Methods and compositions for targeted two-dimensional western blot analysis for early cancer detection and cancer diagnosis up to ten years in advance of clinical symptoms of malignant disease |
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| 申请号 | US15169205 | 申请日 | 2016-05-31 | 公开(公告)号 | US09612243B1 | 公开(公告)日 | 2017-04-04 |
| 申请人 | Mor-NuCo Enterprises, Inc.; | 发明人 | D. James Morre; | ||||
| 摘要 | The present invention includes methods for detecting benign to malignant transformation of a cancer in a subject, comprising the steps of: collecting a sample from the subject prior to electrophoretic protein separation; activating electrophoretically separated ENOX2 transcript variants with an ENOX2 electron donor; and detecting the presence of the one or more activated ENOX2 transcript variants using a pan-ENOX2 detectable binding reagent, wherein the presence of one or more activated ENOX2 transcript variants in the sample is indicative of the malignant transformation of the cancer, whereby a 10 to 100 fold increase in detection sensitivity is obtained for the one or more activated ENOX2 transcript variants when compared to an equivalent non-activated ENOX2 transcript variant. | ||||||
| 权利要求 | What is claimed is: |
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| 说明书全文 | None. The present invention relates in general to the field of cancer detection and diagnosis, and more particularly, to a functionalized single chain variable region recombinant ENOX2 antibody based on NADH-targeted detection. None. The present application includes a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on May 30, 2016, is named MNCE1002.txt and is 18 kilobytes in size. Without limiting the scope of the invention, its background is described in connection with cancer protein biochemistry. There is a unique, growth-related family of cell surface hydroquinone or NADH oxidases with protein disulfide-thiol interchange activity referred to as ECTO-NOX proteins (for cell surface NADH oxidases) (Morre, 1998. Plasma Membrane Redox Systems and Their Role in Biological Stress and Disease (Asard, H., Berczi, A. and Caubergs, R. J., Eds) pp. 121-156, Kluwer Academic Publishers, Dordrecht, Netherlands; Morre and Morre, 2003. Free Radical Res. 37: 795-805). One member of the ECTO-NOX family, designated ENOX2 (for tumor associated) is specific to the surfaces of cancer cells and the sera of cancer patients (Morre et al., 1995. Proc. Natl. Acad. Sci. 92: 1831-1835; Bruno et al., 1992. Biochem. J. 284: 625-628). The presence of the ENOX2 protein has been demonstrated for several human tumor tissues (mammary carcinoma, prostate cancer, neuroblastoma, colon carcinoma and melanoma) (Cho et al., 2002. Cancer Immunol. Immunother. 51: 121-129); and serum analysis suggest a much broader association with human cancer (Morre, et al., 1997. Arch. Biochem. Biophys. 342: 224-230; Morre and Reust, 1997. J. Bioenerg. Biomemb. 29: 281-289). ENOX proteins are ectoproteins anchored in the outer leaflet of the plasma membrane (Morre, 1965. Biochim. Biophys. Acta 1240: 201-208; While the basis for the cancer specificity of cell surface ENOX2 was not previously determined, the concept was supported by several lines of evidence. Drug responsive ENOX2 activity has been rigorously determined to be absent from plasma membranes of non-transformed human and animal cells and tissues (Morre et al., 1995. Proc. Natl. Acad. Sci. 92: 1831-1835). ENOX2 proteins lack a transmembrane binding domain (Morre, et al., 2001. Arch. Biochem. Biophys. 392: 251-256) and are released from the cell surface by brief treatment at low pH (del Castillo-Olivares et al., 1998. Arch. Biochem. Biophys. 358: 125-140). A drug-responsive ENOX2 activity has not been detected in sera from healthy volunteers or patients with diseases other than cancer (Morre, et al., 1997. Arch. Biochem. Biophys. 342: 224-230; Morre and Reust, 1997. J. Bioenerg. Biomemb. 29: 281-289). Several ENOX2 antisera have identified the immunoreactive band at 34 kDa (the processed molecular weight of one of the cell surface forms of ENOX2) by Western blot analysis or immunoprecipitation when using transformed cells and tissues or sera of cancer patients as antigen source (Cho et al., 2002. Cancer Immunol. Immunother. 51: 121-129; Morre, et al., 2001. Arch. Biochem. Biophys. 392: 251-256; Chueh et al., 2002. Biochemistry 44: 3732-3741). The immunoreactive band at 34 kDa is absent with Western blot analysis or immunoprecipitation when using transformed cells and tissues or sera from healthy volunteers or patents with disorders other than cancer (Cho et al., 2002. Cancer Immunol. Immunother. 51: 121-129; Morre, et al., 2001. Arch. Biochem. Biophys. 392: 251-256; Chueh et al., 2002. Biochemistry 44: 3732-374). These antisera include a monoclonal antibody (Cho et al., 2002. Cancer Immunol. Immunother. 51: 121-129), single-chain variable region fragment (scFv) which reacts with the cell surface NADH oxidase from normal and neoplastic cells, polyclonal antisera made in response to expressed ENOX2 (Chueh et al., 2002. Biochemistry 44: 3732-374) and polyclonal peptide antisera to the conserved adenine nucleotide binding region of ENOX2 (Chueh et al., 2002. Biochemistry 44: 3732-374). ENOX2 cDNA has been cloned (GenBank Accession No. AF207881; 11; U.S. Patent Publication 2003/0207340 A1). The derived molecular weight from the open reading frame is 70.1 kDa. Functional motifs include a quinone binding site, an adenine nucleotide binding site, and a CXXXXC cysteine pair as a potential protein disulfide-thiol interchange site based on site-directed mutagenesis (Chueh et al., 2002. Biochemistry 44: 3732-374). Based on available genomic information (Bird, 1999. Direct submission of human DNA sequence from clone 875H3 (part of APK1 antigen) to GenBank database at NCBI) the ENOX2 gene is located on chromosome X, and it is comprised of multiple exons (thirteen). It is known that there are a number of splice variant mRNAs and proteins expressed. The hybridoma cell line that produces the tumor NADH oxidase-specific monoclonal antibody MAB 12.1 was deposited with the American Type Culture Collection, Manassas, Va., 20108 on Apr. 4, 2002, under the terms of the Budapest Treaty. This deposit is identified by Accession No. ATCC PTA-4206. The deposit will be maintained with restriction in the ATCC depository for a period of 30 years from the deposit date, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if the deposit becomes non-viable during that period. This monoclonal antibody is described in U.S. Pat. No. 7,053,188, issued May 30, 2006, which is incorporated by reference herein. Because cancer poses a significant threat to human health and because cancer results in significant economic costs, there is a long-felt need in the art for an effective, economical and technically simple system in which to assay for the presence and organ site of cancer. The present invention includes methods for the analysis of a biological sample for the presence of particular transcript variants of the pan-cancer antigen known as ENOX2 (for tumor-specific NADH oxidase). The present method includes, e.g., a 2-dimensional gel electrophoresis and immunoblotting using an antibody specific for the pan-cancer ENOX2 antigen and the various isoforms, which characterize particular types of cancers. The methods of the present invention can also be applied to evaluate response to therapy, with decreasing amounts of ENOX2 isoform(s) reflecting successful treatment, as well as early detection of recurrent disease (reflected increased or reappearance of ENOX2-specific isoforms. In one embodiment, the present invention includes a method for detecting benign to malignant transformation of a cancer in a subject, comprising the steps of: collecting sample from the subject prior to electrophoretic protein separation; activating electrophoretically separated ENOX2 transcript variants with an ENOX2 electron donor; and detecting the presence of the one or more activated ENOX2 transcript variants using a pan-ENOX2 detectable binding reagent, wherein the presence of one or more activated ENOX2 transcript variants in the sample is indicative of the malignant transformation of the cancer, whereby a 10 to 100 fold increase in detection sensitivity is obtained for the one or more activated ENOX2 transcript variants when compared to equivalent non-activated ENOX2 transcript variants. In one aspect, the ENOX2 electron donor required to activate the ENOX2 transcript variants is selected from at least one of a reduced pyridine nucleotide, NADH, NAD(P)H, or a synthetic substrate that is an ENOX2 electron donor, and detecting the one or more activated ENOX2 transcript variants on the 2D blot, wherein the final concentration of NADH or NAD(P)H is in the range 10 μM to 50 μM. In another aspect, the method further comprises performing two dimensional (2D) electrophoretic protein separation and blotting onto a film or paper. In another aspect, the pan-ENOX2 detectable binding reagent comprises SEQ ID NO:1. In another aspect, the sample is a blood, serum, plasma, urine, cerebrospinal fluid or other body fluid. In another aspect, the pan-ENOX2 detectable binding reagent comprises an anti-ENOX2 scFv fusion protein that is: non-aggregating at between 4° C. and 40° C.; comprises a functional linker between heavy and light chain portions of the ScFv fusion protein comprised primarily of amino acids with small side chains (Gly/Ser) containing, in addition, two cysteine residues (C) spaced as either CXXXXC or CXXXXXC; and is capable of forming an interchain disulfide bond with the protein disulfide-thiol interchange functional motif of ENOX2. In another aspect, the pan-ENOX2 detectable binding reagent comprises an scFv of SEQ ID NO:11, wherein the stability, binding efficiency, and shelf life of the scFv of SEQ ID NO:1 is improved by storing in 50% at −70° C. glycerol to prevent aggregation. In another aspect, the step of concentrating the blood, serum, or plasma sample is defined further as concentrating the one or more ENOX2 transcript variants using a nickel-agarose substrate to bind and concentrate the one or more ENOX2 transcript variants. In another aspect, the method further comprises detecting the cancer and/or determining a tissue of origin of a human cancer at least one year in advance of clinical symptoms. In another aspect, the method further comprises detecting the cancer and/or determining a tissue of origin of a human cancer at least one year (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10 or 20 years) in advance of clinical symptoms. In another aspect, the method further comprises determining a tissue of origin of one or more cancers of unknown primary (CUP). In another aspect, the method further comprises screening for at least one of: early cancer in populations with family cancer histories, environmental exposures, or in a general population. In another aspect, the method further comprises determining a tissue of origin of the one or more activated ENOX2 transcript variants based on the presence of ENOX2 transcript variants as set forth in the following Table 1: In another aspect, the method further comprises resolving proteins at 53 and/or 79 to 85 kDa as total protein loading controls. In another aspect, the method further comprises distinguishing between distant metastases and multiple primary cancers based on the presence of the one or more activated ENOX2 transcript variants. In another aspect, the method further comprises detecting stage 0 and stage 1 cancers and determining the tissue of origin of the cancer. In another aspect, an incidence of false positives and confirmed false negatives of the predicted cancer is less than 1%. In another aspect, the sensitivity of the method for detecting the cancer is greater than 95%. In another aspect, the sensitivity of the method detects the presence of 2 million cancer cells or less. In another aspect, the method further comprises monitoring the reemergence of the cancer, therein the presence of 2 million or less cancer cells is detectable based on the reemergence of the one or more activated ENOX2 transcript variants. In another aspect, the method further comprises determining between malignant and benign early neoplastic lesions, wherein if a benign legion is detected a step of performing surgery, chemotherapy, or radiation therapy may be avoided. In another aspect, the method further comprises determining an early indication of prostate cancer. In another aspect, the method further comprises determining a ductile mammary carcinoma in situ and in need of curative early intervention to potentially avoid surgery, the need for radiation or chemotherapy, prior to the development of ductal mammary carcinoma. In another aspect, the benign to malignant transformation is detected at least one year before development of clinical symptoms. In another aspect, the tissue of origin of the cancer detected is selected from at least one of bladder, blood cell, lymphomas, leukemias, multiple myelomas and myelomas breast, cervical, colorectal, esophageal, gastric, hepatocellular, lung, non-small cell, melanoma, mesothelioma, ovarian, pancreatic, prostate, renal cell (kidney), sarcoma, squamous cell, testicular germ cell, thyroid follicular, thyroid papillary, or uterine (endometrial). Yet another embodiment of the present invention includes a calibrated method of quantitation of ENOX2 transcript variants on a western blot comprising: subjecting a sample from the subject concentrated sample to electrophoretic protein separation; western blotting the electrophoretically separated proteins onto a protein capture film or paper; activating one or more ENOX2 transcript variants on the protein capture film or paper with a reduced ENOX2 substrate; and detecting the presence of the one or more activated ENOX2 transcript variants using a pan-ENOX2 detectable binding reagent, wherein a presence of one or more activated ENOX2 transcript variants in the blood, serum, or plasma sample is indicative of the malignant transformation of the cancer, wherein a 10 to 100 fold increase in detection sensitivity for ENOX2 is obtained when compared to the non-activated ENOX2, wherein the amount of the amount of one or more activated ENOX2 transcript variants is calibrated based on a spot diameter and an intensity of the ENOX2 transcript variant on the protein capture film or paper when compared to a known amount of the one or more ENOX2 transcript variants. In one aspect, the spot diameter is compared to a standard curve of recombinant ENOX2. In another aspect, the spot diameter and the log of the mass of ENOX2 are linearly correlated. Yet another embodiment of the present invention includes a method for determining the tissue of origin of a cancer in a subject comprising: subjecting proteins in a sample from the subject to a two-dimensional (2D) molecular weight and isoelectric point electrophoretic protein separation; transferring the proteins to a protein capture film or paper; activating the electrophoretically separated ENOX2 transcript variants by incubation with an ENOX2 electron donor on the protein capture film or paper; detecting the activated ENOX2 transcript variants; and determining the tissue of origin of the cancer based on the presence of one or more activated ENOX2 transcript variants in the sample from the Table 1, wherein activation of the one or more ENOX2 transcript variants in situ increases the detection sensitivity by 10 to 100 fold when compared to non-activated ENOX2 transcript variants. In another aspect, the ENOX2 electron donor required to activate the ENOX2 transcript variants is selected from at least one of a reduced pyridine nucleotide, NADH, NAD(P)H, or a synthetic substrate that is an ENOX2 electron donor, and detecting the one or more activated ENOX2 transcript variants on the 2D blot, wherein the final concentration of NADH or NAD(P)H is in the range 10 μM to 50 μM. In another aspect, the method further comprises performing two dimensional (2D) electrophoretic protein separation and blotting onto a film or paper, wherein the ENOX2 electron donor is selected from at least one of a reduced pyridine nucleotide, NADH, NAD(P)H, or a synthetic substrate that is an ENOX2 electron donor, and detecting the one or more activated ENOX2 transcript variants on the 2D blot, wherein the final concentration of NADH or NAD(P)H is in the range 10 μM to 50 μM. In another aspect, the pan-ENOX2 detectable binding reagent comprises SEQ ID NO:11. In another aspect, the pan-ENOX2 detectable binding reagent comprises an anti-ENOX2 scFv fusion protein is: non-aggregating at between 4° C. and 40° C.: comprises a small side chain (Gly/Ser) amino acid residues containing two cysteines (C) spaced as either CXXXXC or CXXXXXC; and is capable of forming interchain disulfide bonds with the protein disulfide-thiol interchange functional motif of ENOX2. In another aspect, the pan-ENOX2 detectable binding reagent comprises an scFv of SEQ ID NO:11, wherein the stability, binding efficiency, and shelf life of the scFv of SEQ ID NO:11 is improved by storing in 50% glycerol at −70° C. to prevent aggregation. In another aspect, the step of concentrating the sample is defined further as concentrating the one or more ENOX2 transcript variants using a nickel-agarose substrate to bind and concentrate the one or more ENOX2 transcript variants. In another aspect, the method further comprises detecting the cancer and/or determining a tissue of origin of a human cancer at least one year in advance of clinical symptoms. In another aspect, the sample is a blood, serum, plasma, urine, cerebrospinal fluid or a body fluid. Yet another embodiment of the present invention includes a blot comprising one or more electrophoretically separated proteins from a concentrated sample from a subject, wherein the blot is exposed to a pan-ENOX2 detecting reagent and to a reducing substrate for ENOX2 that activates the ENOX2 transcript variants on the blot, wherein the blot is analyzed for the present of one or more activated ENOX2 transcript variants from Table 1, wherein the presence of the one or more activated ENOX2 transcript variants is used to detect and determine a tissue of origin of a human cancer at least one year in advance of clinical symptoms, and the activation of the one or more ENOX2 transcript variants in situ increases the detection sensitivity by 10 to 100 fold when compared to non-activated ENOX2 transcript variants. For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures and in which: While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims. The field of this invention is a serum-based assay for early pan-cancer diagnosis of cancer that permits detection of cancer up to ten years in advance of clinical symptoms of malignant disease based on a specific functionalized single chain variable region recombinant antibody targeted to a cancer-specific family of cell surface ENOX2 proteins whereby molecular weights and isoelectric points of tissue of origin-specific transcript variants determined by using two-dimensional gel electrophoresis with an ENOX2-specific recombinant scFv antibody combined with NADH-targeted technology providing ten- to 100-fold enhanced sensitivity over the previously developed protocols. Ecto-Nicotinamide Adenine Dinucleotide Oxidase Disulfide Thiol Exchanger 2 (ENOX2) (GenBank accession no. AF207881; Chueh et al., 2002) also known as Tumor Associated Nicotinamide Adenine Dinucleotide Oxidase (ENOX2) is ideally suited as a target for early diagnosis as well as for early preventive intervention ( The present invention provides a method for the analysis of a biological sample for the presence of particular isoforms of the pan-cancer antigen known as ENOX2 (for tumor-specific NADH oxidase). The present method entails 2-dimensional gel electrophoresis and immunoblotting using an antibody specific for the pan-cancer ENOX2 antigen and the various isoforms which characterize particular types of cancers. As specifically exemplified, about 30 μL of sera are loaded for analysis. ENOX2 transcript variants are identified on the basis of their molecular weights and isoelectric point with detection using a ENOX2-specific monoclonal antibody (MAb) (U.S. Pat. No. 7,053,188), using single chain variable region (scFv) fragment which recognizes all cell surface NOX proteins (both age-related, normal cell and neoplasia specific NADH oxidase) or using polyclonal sera raised against ENOX2. The ECTO-NOX proteins are first enriched and concentrated from a biological sample, desirably a serum sample, by binding to nickel-agarose and then eluting. After release of the proteins from the nickel agarose by vortexing, the proteins are separated in the first dimension by isoelectric focusing and in the second dimension by polyacrylamide gel electrophoresis. As specifically exemplified herein, the isoelectric focusing step is over a pH range from 3 to 10, and size separation is over a 10% polyacrylamide gel. Most of the cancer-specific ENOX2 isoforms exhibit isoelectric points in a very narrow range between pH 3.9 and 6.3 but differ in molecular weight from 34 to 136 kDa. In the 2D gel system specifically exemplified, the cancer-specific isoforms are located in Quadrants I (relatively high molecular weight material) and IV (lower molecular weight material, notably the range of 30 to 50 kDa. IgG heavy chains (Quadrant II and IgG light chains (Quadrant III) cross react with the scFv antibody and along with reference proteins at 53 and 79 to 85 kDa serve as loading controls. The absence of all ENOX2 isoforms indicates the absence of cancer or a cumulative cancer size below the limit of detection in the assay. The presence of an ENOX2 isoform indicates the presence of cancer. The particular molecular weight present in a serum sample or a particular combination of isoforms provides an indication of the cell type or tissue of origin of the cancer. The method not only determines cancer presence, but also the method of the present invention provides diagnostic information concerning the tissue of origin. At present there are no other pan cancer (all forms of human cancer) tests with these particular capabilities. ENOX2 transcript variants with apparent molecular weights in the range of 64-69 kDa. pH in the range of 4.2-4.9 are associated with breast cancer. ENOX2 transcript variants of 52-53 kDa, pH 4.1-4.6 is associated with small cell lung cancer. An ENOX2 transcript variant of 54-56 kDa, pH 4.6-5.3 is associated with non-small cell lung cancer. Two ENOX2 transcript variants of about 72-90 kDa and 37-47 kDa, isoelectric point pH 3.7-5.0 for both, characterize ovarian cancer. ENOX2 transcript variants of 71-88 kDa, pH 5.1-6.5 are associated with prostate cancer. An ENOX2 transcript variant of about 90-100 kDa, pH 4.2-5.4 signals cervical cancer. Three ENOX2 transcript variants of about 80-96 kDa, pH 4.4-5.4; 50-65 kDa, pH 4.2-5.3; and 33-46 kDa, pH 3.8-5.2 are characteristic of colon cancer. Where a patient is suspected of having cancer, the 2D gel electrophoresis/immunological analysis of a biological sample, advantageously a serum sample will reveal both cancer presence and organ site with the present invention. Method 1—Ten- to 100-Fold Increase in Sensitivity and Specificity of the Western Blot Detection Protocol. Using the present invention a ten- to 100-fold increase in sensitivity and specificity of the western blot detection protocol was derived from an observation that there was a delay time of the inhibition of NADH oxidation following exposure of serum ENOX2 to an antibody combining site inhibitory ligand. The inhibition was observed to occur at various time between 0 and 22 minutes (22 minutes is the length of the ENOX 2 activity cycle; (Wang et al., 2001. Biochim. Biophys. Acta 1539:i92-204) during a 30 minute incubation. Thus, the time during each 22 min activity cycle where the EEMTE antibody combining site is available for combination with antibody is relatively brief, and in the order of less than 5 minutes. Also, the ENOX2 protein must be active in order for the antibody to gain access to the binding site during this relatively short window of opportunity. Table 2 shows the activity of ENOX2 at the five activity maxima during 5 successive 22 minutes activity cycles following antibody addition. Inhibition occurs at maximum 4 within the 22 min activity cycle. Thus, antibody binding must occur exclusively during maximum 4 since maximum 5 is the first maximum to be inhibited. Antibody addition at maximum 5 had no effect nor did antibody addition before maximum 4. A corollary of the above result is that antibody will not bind or will bind only poorly to inactive ENOX2 transcript variants. Therefore, steps were initiated to render ENOX2 on western blots active during incubation with antibody. In order to maintain an active ENOX2 during western blotting with antibody, following blocking for 10 minutes with 1% milk and two rinses with TBST to remove excess milk, reduced pyridine nucleotides [NAD(P)H] were added at a concentration of 15 μM during incubation with the primary scFv antibody. NADH is preferred at a final concentration in the range of 10 μM. Incubation of the blot with antibody with or without shaking at any temperature between 4° C. and 40° C. for times of 1 to 16 hours depending on the concentration of NADH, the temperature and the antibody titer, preferably with incubation at 4° C. overnight (approximately 16 hours) with shaking. The cancer diagnostic system of the present invention utilizes two-dimensional polyacrylamide gel electrophoretic techniques for the separation of proteins in human sera to generate cancer-specific isoform patterns and compositions indicative of cancer presence, tumor type, disease severity and therapeutic response. The protocol is designed for the detection of at least 26 cancer-specific patterns of ENOX2 transcript variants each denoting a different tumor type representing 20 different tissue of cancer origin, which are resolved to indicate cancer presence and origin of the primary cancer. This specification illustrates the process of the transcript-resolving two-dimensional gel electrophoresis protocol and subsequent immunoanalysis to detect ENOX2 transcript variants that reflect particular cancers. Two-dimensional gel electrophoresis separates by displacement in two dimensions oriented at right angles to one another and immunoblotting identifies the ENOX2 isoforms. In the first dimension variants are separated by isoelectric point (pI) according to charge by isoelectric focusing (IEF). The variants are then separated according to molecular weight in kilodaltons (kDa) by SDS-PAGE in a second dimension. The isoforms are then blotted onto a nitrocellulose membrane for further analysis using the pan-cancer specific antibody preparation containing a functional linker that stabilizes antibody binding to the transcript variants. The opportunity to simultaneously determine both cancer presence and cancer tissue of origin emerged as a result of 2-dimensional gel electrophoretic separations where western blots with a pan ENOX2 recombinant single chain variable region (scFv) antibody carrying an S tag ( Method 2—ENOX Transcript Variants of Specific Molecular Weights and Isoelectric Points are Produced Uniquely by Patients with Cancer. The transcript variants are shed into the circulation and have the potential to serve as definitive, non-invasive and sensitive serum markers for early detection of both primary and recurrent cancer in at risk populations with a low incidence of both false positives, and false negatives as they are molecular signature molecules produced specifically by cancer cells and absent from non-cancer cells. As the 2-D-western blot protocol detects cancer early, well in advance of clinical symptoms, the opportunity to combine early detection with early intervention as a potentially curative prevention strategy for cancer is provided whereby elimination of the disease in its very earliest stages is uniquely possible. Analytical 2-D gel electrophoresis and immunoblotting of ENOX proteins from a mixed population of cancer patients (bladder, blood cell (leukemias, lymphomas, and myelomas), breast, cervical, colorectal, esophageal, gastric, hepatocellular, lung, melanoma, ovarian, pancreatic, prostate, renal cell (kidney), sarcoma, squamous cell, testicular germ cell, thyroid, and uterine (endometrial) revealed multiple species of acidic proteins of molecular weight between 34 and 100 kDa in quadrants I and IV ( Sera from individual patients with various forms of cancer were analyzed by 2-D gel electrophoresis and immunoblotting to assign each of the ENOX2 isoforms of The protein sequence of ENOX2 exhibits similarity with the two reference proteins alpha-fetuin and serrotransferrin reactive with the pan ENOX2 scFv recombinant antibody. Regions of similarity are restricted to a 7 amino acid sequence (underlined) adjacent in ENOX2 to the E394EMTE398 quinone inhibitor-binding site, which serves as the antigen sequence to which the specific scFv antibodies bind. A. Sample Preparation
B. Isoelectric Focusing (First Dimension)
Run Parameters: C. Prepare SDS-Page Gels (for Second Dimension)
D. Equilibration (First Dimension)
E. SDS-PAGE (Second Dimension)
F. Protein Transfer (for Western Blot)
G. Immunological Analysis for Western Blot Using scFv with S-Tag Linked to Alkaline Phosphatase or Alkaline Phosphatase Linked Anti S-Tag so as to Amplify Signal
H. Development of Western Blot and Scanning
Solutions Used for First Dimension I. Rehydration Buffer pH 7 (25 mL): Solutions Used for Second Dimension Tris Buffer (1.5 M, pH 8.8) (1 L): Equilibration Buffer (400 mL): Acrylamide Gel (20 cm×20 cm; 1-mm Thick) 10% Alkaline Phosphatase Substrate (APS) Agarose Solution (1%): 10×SDS Running Buffer (4 L): Solutions for Western Blot Western Transfer Buffer (4 L): Blocking Buffer (5% BSA) 10× Tris Buffered Saline with Tween-20 (TBST) (4 L) Method 3—2-D Gel Electrophoresis Western Blot Early Detection Protocol. Serum was prepared from 5 ml of blood collected by venipuncture (with tourniquet) in standard B & D 13×100 (7 ml) vacutainer clot tubes (or equivalent) with or without hemoguard closure. After approximately 30 minutes at room temperature to allow for clotting, the clot was pelleted by centrifugation for 5 to 10 minutes at 2,500 to 3,000 rpm. Clot-free serum was decanted into a clean tube, labeled and analyzed fresh or stored frozen. For western blot analysis, 30 μL of sera was added to 120 μL of Rehydration Buffer (7M urea, 2 M thiourea, 2% (w/v) CHAPS [(3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate), a nondenaturing zwitterionic detergent], 0.5% (w/v) ASB-14 (amidosulfobetaine-14, a zwitterionic detergent), 0.5% (v/v) ampholytes pH 3-10 (Bio-Rad), 0.5% (v/v) immobilized pH gradient (IPG) buffer pH 3-10 (Amersham-Pharmacia Biotech) and 65 mM dithiothreitol). The samples were quickly vortexed to mix sera with Rehydration Buffer. Four to six mg of protein were loaded for analysis. The samples were electrophoresed in the first dimension by using a commercial flatbed electrophoresis system (Ettan IPGphor 3, Amersham-Pharmacia Biotech) with IPG dry strips (Amersham). A linear pH range of 3 to 10 on 7 cm IPG strips was used. The IPG strips were rehydrated with the samples overnight at room temperature. The strips were then focused at 50 mA per strip and at increasing voltage of 250 V for 250 Vhrs, 500 V for 500 Vhrs, 1,000 V for 1,000 Vhrs and 4,000 V for 3 hours. The samples were then focused at a constant 4,000 V for 28,000 Volt-hours. After isoelectric focusing, the IPG strips were re-equilibrated for 20 minutes in 2.5% (w/v) SDS, 6 M urea, 30% (v/v) glycerol, 100 mM Tris-HCl (pH 8.8). The strips were placed onto linear SDS-PAGE gels (10% (w/v) polyacrylamide) and electrophoresed at a constant 250 V for 75 minutes. The samples were then transferred to nitrocellulose membranes by electroblotting using the Bio-Rad Trans-Blot Electrophoretic Transfer Cell. The membranes were blocked using milk protein (1% low fat dry milk) at room temperature for 10 minutes. Detection was with recombinant anti-ENOX2 single chain variable region of antibody (scFv) that was alkaline phosphatase-linked overnight at 4° C. After washing, detection was performed with Western Blue nitrotetrazolium (NBT) substrate (Promega, Madison, Wis.; Cat. No. 53841) at room temperature. Images were scanned and processed using Adobe Photoshop. Quantitation utilized an algorithm developed for this purpose. Reactive proteins appeared reddish blue. For interpretative purposes, the blots were divided into quadrants I-IV with unreactive serum albumin at the center ( Two-fold increase in spot size and density of different amounts of ENOX2 in the assay as determined by 2-D gel electrophoresis/western blot analysis comparing incubation in the presence of 15 μM NADH in the assay compared to no NADH ( Analyses of sera from 1,626 cancer patients with confirmed diagnoses of cancer (Table 1, repeated from the Summary of the Invention) showing non-lapping patterns of number of transcript variants (protein 1 to protein 3), molecular weights and isoelectric points that distinguish 26 different cancers and 20 different tissues of origin. Table 1, repeated from the Summary of the Invention: Ranges for Molecular Weight (MW) and Isoelectric Point (Pi) Determined for Sera of Patients Diagnosed with 24 Different Cancers Representing 20 Different Tissues of Origin The ONCOblot test correctly identified cancers as to tissue of origin with both state 0 and Stage I cancers (Table 3). Often referred to as cancer in situ, with stage 0 and stage I cancers, the disease has not spread beyond the tissue of origin. Thus, the ONCOblot Cancer Test signals cancer earlier than Circulating Tumor Cell tests that detect only cancer cells in the blood. A 64 year old male was followed longitudinally for 16 years by using archived serum samples. The starting PSA was 0.8 ng/mL. No clinical symptoms were recorded until year 16 when prostate cancer was confirmed by biopsy. ENOX2 was first detected in year 8 with a PSA of 4 ng/ml 8 years in advance of clinical symptoms. Malignant mesothelioma is an aggressive, almost uniformly fatal cancer caused primarily by exposure to asbestos. Sequential serum samples collected from asbestos-exposed individuals prior to the development of frank mesothelioma were assayed for ENOX2 presence by 2-D gel-immunoblot analysis to determine how long in advance of clinical symptoms mesothelioma-specific transcript variants could be detected. Two mesothelioma-specific transcript variants were detected in the sera of asbestos-exposed individuals 4 to 10 years prior to clinical diagnosis of malignant mesothelioma (average 6.2 years). Either one or both ENOX2 protein transcript variants indicative of malignant mesothelioma were absent in 14 of 15 subjects diagnosed with benign pleural plaques either with or without accompanying asbestosis. Analysis of patient sera with cancer of unknown primary (CUP). The 2-D gel from a patient with cancer where the primary tumor was unknown revealed the presence of 80 and 42.5 kDa, both with transcript variants of isoelectric points of pH 4.2 and 4.1 to indicate that the primary cancer was ovarian cancer, which was confirmed later by biopsy. Successful validation and quantitation of ENOX2 presence in 1,587 ONCOblot analyses comparing 20 different tissues of origin (Table 1). Early detection of cancer in a healthy population of young adults in advance of clinical symptoms. Sera from 100 subjects (50 male and 50 female) between the ages of 20 and 39 years were analyzed for ENOX2 presence by the technology described herein. In the age group 20-29 years, none of the 25 females and only one (colorectal) of the 25 males exhibited ENOX2 proteins indicative of cancer presence. Similarly, in the age group 30-39 years, one (blood cell) of the 25 females and one (prostate) of the 25 males exhibited ENOX2 proteins. Therefore, the overall incidence of ENOX2 presence within all 100 serum samples was 3%. The overall incidence of newly diagnoses cancers within a population of men and women between 20 and 29 years old is approximately 2% (Howlander et al. SEER Cancer Statistics Review, 1975-2012, National Cancer Institute, Bethesda, Md.). Method 4—Generation of Functionalized Recombinant Antibody with Protein Disulfide-Thiol Interchange Functional Motif Represented in Linker. To further enhance the affinity and specificity of the binding of the recombinant antibody to ENOX2 on western blots a linker was designed to specifically mimic the protein disulfide-thiol interchange functional motif of the ENOX2 family of proteins. Monoclonal antibody generated against ENOX2 NADH oxidase tumor cell specific was produced in sp-2 myeloma cells; however, the monoclonal antibody slowed the growth of sp-2 myeloma cells that were used for fusion with spleen cells after 72 hours. This phenomenon made it difficult to produce antibody in quantity. To overcome this problem, the coding sequences of the antigen-binding variable region of the heavy chain and the light chain (Fv region) of the antibody cDNA were cloned and linked into one chimeric gene, upstream of the S-tag coding sequence. The Fv portion of an antibody, consisting of variable heavy (VH) and variable light (VL) domains, can maintain the binding specificity and affinity of the original antibody (Glockshuber et al. 1990. Biochemistry 29:1262-1367). For a recombinant antibody, cDNAs encoding the variable regions of immunoglobulin heavy chain (VH) and light chain (VI), were cloned using degenerative primers. Mammalian immunoglobulins of light and heavy chain contain conserved regions adjacent to the hypervariable complementary defining regions (CDRs). Degenerate oligoprimer sets allow these regions to be amplified using PCR (Jones et al. 1991. Bio/Technology 9:88-89; Daugherty et al. 1991. Nucleic Acids Research 19:2471-2476). Recombinant DNA techniques have facilitated the stabilization of variable fragments by covalently linking the two fragments by a polypeptide linker (Huston et al. 1988. Proc. Natl. Acad. Sci. USA 85:5879-5883). Either VL or VH can provide the NH2-terminal domain of the single chain variable fragment (scFv). The linker should be designed to resist proteolysis and to minimize protein aggregation. Linker length and sequences contribute and control flexibility and interaction with scFv and antigen. The preferred linker was uniquely comprised as a functional linker between heavy and light chain portions of the ScFv fusion protein comprised primarily of amino acids with small side chains (Gly/Ser) containing, in addition, two cysteine residues (C) spaced as either CXXXXC or CXXXXXC; that forms interchain disulfide bonds with the protein disulfide-thiol interchange functional motif of ENOX2. Total RNA was isolated from the hybridoma cells producing ENOX2-specific monoclonal antibodies by the following procedure modified from Chomczynski et al. (1987) Anal. Biochem. 162:156-159 and Gough (1988) Anal. Biochem 176:93-95. Cells were harvested from medium and pelleted by centrifugation at 450×g for 10 minutes. Pellets were gently resuspended with 10 volumes of ice cold PBS and centrifuged again. The supernatant was discarded and cells were resuspended with an equal volume of PBS. Denaturing solution (0.36 ml of 2-mercaptoethanol/50 ml of guanidinium stock solution-4M guanidinium thiocyanate, 25 mM sodium citrate, pH 7.0, 0.5% sarkosyl) 10 ml per 1 g of cell pellet was added prior to use and mixed gently. Sodium acetate (pH 4.0, 1 ml of 2M), 10 ml of phenol saturated water and 2 ml of chloroform: isoamyl alcohol (24:1) mixtures were sequentially added after each addition. The solution was mixed thoroughly by inversion. The solution was vigorously shaken for 10 seconds, chilled on ice for 15 minutes and then centrifuged 12,000×g for 30 minutes. The supernatant was transferred and an equal volume of 2-propanol was added and placed at −20° C. overnight to precipitate the RNA. The RNA was pelleted for 15 minutes at 12,000×g, and the pellet was resuspended with 2-3 ml of denaturing solution and 2 volumes of ethanol. The solution was placed at −20° C. for 2 hours, and then centrifuged at 12,000×g for 15 minutes. The RNA pellet was washed with 70% ethanol and then 100% ethanol. The pellet was resuspended with RNase-free water (DEPC-treated water) after centrifugation at 12,000×g for 5 minutes. The amount of isolated RNA was measured spectrophotometrically and calculated from the absorbance at 280 nm and 260 nm. A poly(A)mRNA isolation kit was purchased from Stratagene. Total RNA was applied to an oligo(dT) cellulose column after heating the total RNA at 65° C. for 5 minutes. Before applying, the RNA samples were mixed with 500 μL of 10× sample buffer (10 mM Tris-HCl, pH 7.5, 1 mM EDTA, 5 M NaCl). The RNA samples were pushed through the column at a rate of 1 drop every 2 seconds. The eluates were pooled and reapplied to the column and purified again. Preheated elution buffer (65° C.) was applied, and mRNA was eluted and collected in 1.5 ml of centrifuge tubes on ice. The amount of mRNA was determined at OD260 (1 OD unit=40 μg of RNA). The amounts of total RNA and mRNA obtained from 4×10 e 8 cells were 1328 μg and 28 μg, respectively. Next, mRNA (1-2 μg) dissolved in DEPC-treated water was used for cDNA synthesis. mRNA isolated on three different dates was pooled for first-strand cDNA synthesis. The cDNA synthesis kit was purchased from Pharmacia Biotech. The mRNA (1.5 μg/5 μL of DEPC-treated water) was heated at 65° C. for 10 minutes and cooled immediately on ice. The primed first strand mix containing Murine Leukemia Virus (MuLV) reverse transcriptase (11 μL) and appropriate buffers for the reaction were mixed with the mRNA sample. DTT solution (1 μL of 0.1 M) and RNase-free water (16 μL) also were added to the solution. The mixture was incubated for 1 hour at 37° C. Degenerate primers for light chain and heavy chain (Novagen, Madison, Wis.) were used for PCR. PCR synthesis was carried out in 100 μL reaction volumes in 0.5 ml microcentrifuge tubes by using Robocycler (Stratagene, La Jolla, Calif.). All PCR syntheses included 2 μL of sense and anti-sense primers (20 picomoles/μL), 1 μL of first-strand cDNA as a template, 2 μL of 10 mM of dNTPs, 1 μl of Vent polymerase (2 units/μL), 10 μL of 10×PCR buffer (100 mM Tris-HCl, pH 8.8 at 25° C., 500 mM KCl, 15 mM MgCl2, 1% Triton X-100), 82 μL of H2O. Triton X-100 is t-octylphenoxypolyethoxyethanol. All PCR profiles consisted of 1 min of denaturation at 94° C., 1 minute of annealing at 55° C., and 1 minute of extension at 72° C. This sequence was repeated 30 times with a 6-minute extension at 72° C. in the final cycle. PCR products were purified with QIAEX II gel extraction kit from Qiagen, Valencia, Calif. PCR amplification products for heavy and light chain coding sequences were analyzed by agarose gel electrophoresis and were about 340 base pair (bp) long and 325 bp long, respectively. Total RNA or DNA was analyzed by agarose gel electrophoresis (1% agarose gels). Agarose (0.5 g in 50 ml of Tris-acetate-EDTA (TAE) buffer, 40 mM Tris-acetate, 1 mM EDTA) was heated for 2 minutes in a microwave to melt and evenly disperse the agarose. The solution was cooled at room temperature, and ethidium bromide (0.5 μg/ml) was added and poured into the apparatus. Each sample was mixed with 6× gel loading buffer (0.25% bromophenol blue, 0.25% xylene cyanol FF, 40% (w/v) sucrose in water). TAE buffer was used as the running buffer. Voltage (10 v/cm) was applied for 60-90 minutes. According to the proper size for heavy and light chain cDNAs, the bands were excised from the gels under UV illumination, and excised gels were placed in 1 ml syringes fitted with 18-gauge needles. Gels were crushed to a 1.5 ml Eppendorf tube. The barrel of each syringe was washed with 200 μL buffer-saturated phenol (pH 7.9±0.2). The mixture was thoroughly centrifuged and frozen at −70° C. for 10 minutes. The mixture was centrifuged for 5 minutes, and the top aqueous phase was transferred to a new tube. The aqueous phase was extracted again with phenol/chloroform (1:1). After centrifuging for 5 minutes, the top aqueous phase was transferred to a clean tube, and chloroform extraction was performed. Sodium acetate (10 volumes of 3 M) and 2.5 volumes of ice-cold ethanol were added to the top aqueous phase to precipitate DNA at −20° C. overnight. Purified heavy and light chain cDNAs were ligated into plasmid pSTBlue-1 vector and transfected into NovaBlue competent cells (Stratagene). Colonies containing heavy and light chain DNAs were screened by blue and white colony selection and confirmed by PCR analysis. Heavy and light chain DNAs were isolated and sequenced using standard techniques. PCR amplification and the assembly of single scFv gene was according to Davis et al. (1991) Bio/Technology 9:165-169. Plasmid pSTBlue-1 carrying VH and VL genes were combined with all four oligonucleotide primers in a single PCR synthesis. Following first PCR synthesis, one tenth of the first PCR product was removed and added to a second PCR reaction mixture containing only the primer a (VH sense primer) and primer d (VL Antisense primer). The product of the second PCR synthesis yielded single scFv gene. The single scFv gene was ligated to plasmid pT-Adv (Clontech, Palo Alto, Calif.). pT-Adv carrying scFv gene was used for DNA sequencing. The complete functionalized scFv gene was assembled from the VH, VL and linker sequences to yield an scFv cDNA with a high degree of efficacy and sensitivity. Total RNA or DNA was analyzed by agarose gel electrophoresis (1% agarose gels). Agarose (0.5 g in 50 ml of TAE buffer, 40 mM Tris-acetate, 1 mM EDTA) was heated for 2 minutes in a microwave to melt and evenly disperse the agarose. The solution was cooled at room temperature, and ethidium bromide (0.5 μg/ml) was added and poured into the apparatus. Each sample was mixed with 6× gel loading buffer (0.25% bromophenol blue, 0.25% xylene cyanol FF, 40% (w/v) sucrose in water). TAE buffer was used as the running buffer. Voltage (10 v/cm) was applied for 60-90 minutes. According to the proper size for heavy and light chain cDNAs, the bands were excised from the gels under UV illumination, and excised gels were placed in 1 ml syringes fitted with 18-gauge needles. Gels were crushed to a 1.5 ml Eppendorf tube. The barrel of each syringe was washed with 200 μL of buffer-saturated phenol (pH 7.9.+/−.0.2). The mixture was thoroughly centrifuged and frozen at −70° C. for 10 minutes. The mixture was centrifuged for 5 minutes, and the top aqueous phase was transferred to a new tube. The aqueous phase was extracted again with phenol/chloroform (1:1). After centrifuging for 5 minutes, the top aqueous phase was transferred to a clean tube, and chloroform extraction was performed. Sodium acetate (10 volumes of 3 M) and 2.5 volumes of ice-cold ethanol were added to the top aqueous phase to precipitate DNA at −20° C. overnight. Purified heavy and light chain cDNAs were ligated into plasmid pSTBlue-1 vector and transfected into NovaBlue competent cells (Stratagene). Colonies containing heavy and light chain DNAs were screened by blue and white colony selection and confirmed by PCR analysis. Heavy and light chain DNAs were isolated and sequenced using standard techniques. PCR amplification and the assembly of single scFv gene was according to Davis et al. (1991) Bio/Technology 9:165-169. Plasmid pSTBlue-1 carrying VH and VL genes were combined with all four oligonucleotide primers in a single PCR synthesis. Following first PCR synthesis, one tenth of the first PCR product was removed and added to a second PCR reaction mixture containing only the primer a (VH sense primer) and primer d (VL Antisense primer). The product of the second PCR synthesis yielded single scFv gene. The single scFv gene was ligated to plasmid pT-Adv (Clontech, Palo Alto, Calif.). pT-Adv carrying scFv gene was used for DNA sequencing. The complete functionalized scFv gene was assembled from the VH, VL and linker sequences to yield a scFv cDNA by PCR as follows: DNA and Amino Acid Sequence of scFv(S)(GST) with Gly.Ser.Cys Linker [scFv(SC)] Linker Sequence DNA and Amino Acid Sequence of scFv(GST) GST-Tag scFv Heavy Chain (VH) Linker Sequence scFv Light Chain (VL) DNA Sequence of scFv(SC) with GST Tag Translation of scFv(S)(GST) with Gly.Ser.Cys Linker DNA Sequence SEQ ID NO:10 and Amino Acid Sequence SEQ ID NO:11: Translated Protein Sequence: Analysis of Protein Sequence: Length in amino acids: 477 Molecular weight in kD: 53.52 Iso-electric point (IP): 5.87 Molar absorption coefficient (in L/mol/cm); all cysteine residues as disulfide bonds: 1.02E+05 Molar absorption coefficient (in L/mol/cm); 50 percent of cysteine residues as disulfide bonds: 1.02E+05 Molar absorption coefficient (in L/mol/cm); no disulfide bonds: 1.01E+05 1. Primer Design Linker with Gly.Ser.Cys Design for Primers 1. Forward Primer for scFv(S) Heavy Chain for PCR Amplification 2. Reverse Primer for scFv(S) Heavy Chain for PCR Amplification scFv(S) Heavy Chain C-Terminus Plus Linker 1 Reverse Primer for scFv(S) Heavy Chain for PCR Amplification (Primer 18): 3. Forward Primer for scFv(S) Light Chain PCR Amplification Linker Plus scFv(S) Light N-Terminus SEQ ID NO:18 Forward Primer for scFv(S) Light Chain for PCR Amplification (Primer 19): 4. Reverse Primer for scFv(S) Light Chain for PCR Amplification (Primer 17) Primers were ordered from Integrated DNA Technologies (Coralville, Iowa). PCR amplification of heavy chain (VH) and light chain (VL) of scFv(SC). Heavy chain and light chain of scFv(SC) were amplified by polymerase chain reaction (PCR). Conditions for PCR were: PCR Cycle Heavy chain and light chain DNAs of scFv(SC) was analyzed by agarose gel electrophoresis (0.9%). DNA bands were excised, frozen, thawed and centrifuged. scFv(SC) DNA was amplified by extending heavy chain and light chain DNAs by PCR. Conditions for PCR were: The amplified scFv(SC) DNA was analyzed by agarose gel electrophoresis (0.9%). DNA bands were excised, purified by QIAquick Gel Extraction Kit (QIAGEN) and solubilized in 30 μl of TE buffer. Ligation of scFv(SC) to pGEX-4T2 [pGEX4T-scFv(SC)]. scFv(SC) was ligated to pGEXT-4T2. The ligation reaction was as follows: Ligation was 16 hours 50 minutes at 15° C. After ligation, E. coli BL21 (DE3) cells were transformed with pGEX4T-scFv(SC) and plated on LB/ampicillin plate. Cells were grown 37° C. for 20 hours. Screening of colonies for carrying plasmid pGEX4T-scFv(SC). Seven colonies were screened for carrying plasmid pGEX4T-scFv(SC) by PCR. Cells were picked from colony 1, grown in 100 ml of LB/ampicillin media and plasmid was purified using plasmid purification kit (Plasmid Midi Kit, Qiagen). scFv(SC) DNA sequence was performed by Purdue University. The sequenced DNA was analyzed by Alignment algorithm (NCBI) and showed no mutation.
Alignment of scFv(SC) with Sequenced DNA Expression of scFv(SC) BL21(DE3) cells carrying plasmid pGEX4T-scFv(SC) was inoculated in 10 ml of LB/carbenicillin (100 μg/ml). Cells were grown for 6 hr and centrifuged at 6,000 rpm (3,700×g) for 6 minutes. Supernatant was discarded and pellet was resuspended in fresh 2 ml of LB/ampicillin (100 μg/ml) and transferred to two 100 ml LB/amp media in 250 ml-Erlenmyer flask. Cells were grown 3 hours at 37° C. at 250 rpm. Temperature was lowered to 25° C. and IPTG was added (0.15 mM final concentration). Cells were grown additionally 15 hours, harvested and resuspended in 20 ml of 20 mM Tris-HCl, pH 8.0 buffer. Proteins were extracted by French Pressure (3 passages at 20,000 psi). Expression of scFv(SC) was analyzed by SDS-PAGE followed by Ponceau S staining and western blot. scFv(SC) was expressed both as soluble protein and as insoluble inclusion bodies. 1D Western blot analysis of scFvSC. Reactivity of scFv(SC) toward recombinant ENOX2 was analyzed by 1 dimensional western blot. Recombinant ENOX2 was separated by SDS-PAGE and transferred to nitrocellulose membranes. Nitrocellulose membranes were incubated with scFv(SC) for 17 hours and alkaline phosphatase linked S-protein for 2 hours. Detection was with Western Blue (Promega). scFv(SC) reacted toward recombinant ENOX2. For comparison, scFv(S) was included in the western blot analysis. 2D Western blot analysis of scFvSC. Reactivity of scFv(SC) toward recombinant ENOX2 and transcript variant of serum of prostate cancer patient was analyzed by 2 dimensional western blot. Normal serum spiked with 6 μg of recombinant and serum from prostate cancer patient were separated first by isoelectric focusing and then SDS-PAGE and then transferred to nitrocellulose membranes. Nitrocellulose membranes were incubated with scFv(SC) for 17 hours and alkaline phosphatase linked S-protein for 2 hours. Detection was with Western Blue (Promega). Method 5—Enhancement of the Physical Stability of Concentrated Antibody Solutions An important embodiment of the present invention is to enhance the physical stability of concentrated solutions, while maintaining chemical stability and biological potency. The invention provides scFv antibodies which are at least 99% identical to SEQ ID NO:11 and have a kDa for ENOX2 protein of 7×10−7 M and a purity of at least 95%. A major factor, however, in determining the efficacy of the scFv is its propensity to aggregate. After only ten days of storage at either −70° C. or 4° C., the binding of the purified scFv to recombinant ENOX2 protein was reduced by more than 90%. After much study, this loss of efficacy was traced solely to protein aggregation. Aggregated antibodies do not combine specifically with ENOX2 proteins during western blotting. Aggregation of the functionalized scFv antibody as determined from light scattering measurements is achieved by storage in 50% glycerol and stored at −70° C., essential ingredients in the overall protocol to achieve the desired level of sensitivity and specificity. Activity is lost rapidly by storage in the absence of glycerol. With storage in the presence of 50% glycerol (right), all three reference proteins were approximately two times stronger than in the absence of glycerol (left). Transcript variants (spots) were clearer with storage in 50% glycerol (right) than in its absence (left) These three elements, addition of NADH during antibody binding, modification of the scFv linker peptide to resemble the ENOX2 protein disulfide-thiol interchange functional motif and the use of 50% glycerol to prevent scFv aggregation combine to provide an unprecedented sensitivity of the ONCOblot test to permit detection of cancers more than 10 years in advance of clinical symptoms. Method 6—Determination of the Sensitivity and Limit of Detection of the Functionalized Antibody in the Presence of NADH. The incidence of confirmed false positives and confirmed false negatives is low, less than 1% each (D. J. Morre and D. S. Gilmartin. 2015 ONCOblot Reports 1 (1):1-2). For several cancers, two or more ENOX2 transcript variants must be present within the ONCOblot Tissue of Origin Cancer Test to permit the correct identification of the tissue of origin. These include bladder, colorectal, gastric, mesothelioma, ovarian, renal cell and uterine cancer. If one or more ENOX2 transcript variants are absent or below the limit of detection, the tissue of origin of the cancer may be misidentified. Of the most recent ONCOblots analyzed under the current protocol, the rate of misidentification is 2.8%. Thus, the overall accuracy of the test with clinically diagnosed cancers is at least 95%. When proteins are separated by two-dimensional (2-D) gel electrophoresis and detected by immunoblot, visualized proteins appear as small spherical or oval immunoreactive regions termed “spots.” The average diameter of the spot produced by an ENOX2 protein is proportional to the amount of ENOX2 protein present. To determine the limit of ENOX2 detection by ONCOblot, a standard cure of spot diameter was generated. To this end, a functional 46 kDa form of human ENOX2 was first produced in E. coli and purified to near homogeneity. Various amounts of this recombinant ENOX2 protein were then assayed by ONCOblot. The log of the resulting spot diameter was then plotted against the log of the amount of ENOX2 protein assayed ( ENOX2 proteins within sera of 25 Stage 0 and Stage I cancer patients were detected by ONCOblot (Morre, D. J and Taggart, D. J. 2015. ONCOblot Reports 1(4):1-2). The average concentration of ENOX2 within these sera samples was approximately 990 femtomoles (6×1011 molecules) per 150 μL assay by comparison to the standard curve of If the tumor cells are treated as spheres, then the number of cells in a solid tumor can be calculated by using equation 1, where Vtumor is the volume of the tumor, Vcell is the average volume of a cancer cell, D is the tumor diameter and d is the average diameter of a cancer cell estimated to be 10 um, then a 1.2 mm diameter cancer is calculated to contain approximately 2 million cells. Method 7—How Early Might the Functionalized Test with NADH and Modified Linker Detect Cancer in Advance of Clinical Symptoms. Evidence summarized herein has determined that the capability of the test in its present configuration is to detect cancer between 10 and 20 years in advance of clinical symptoms consistent with the 10-fold increased sensitivity provided. In order to estimate how far in advance if clinical symptoms it would be possible to detect cancer presence by the current functionalized version of the test, a study was designed to determine, by comparison to NCI Seer Cancer Statistics Review (Howlander, N. et al. SEER Cancer Statistics Review, 1875-2912, National Cancer Institute, Bethesda, Md.) estimation of how closely the current test results correlated with overall risk of being diagnosed with cancer comparing six age groups consisting of equal numbers of male and female participants. Actual diagnoses were compared to those predicted by the Seer Cancer Statistics Review of predicted risk of being diagnosed with cancer with increasing age. A total of 300 healthy volunteers without clinical evidence of cancer, 25 males and 25 females in each of six age groups, were analyzed for cancer presence by the current 2-D gel-western blot test with NADH and functionalized linker. Sera were collected by venipuncture and analyzed using IRB approved protocols and informed consent. Findings summarized in Table 5 reveal a relatively high incidence of early cancer detection with the normal healthy population consistent with cancer detection 10 to 20 years in advance of clinical symptoms (see also The overall incidence of positive test was 10% in the 21 to 29 year age group and stabilized at about 22% between 50 and 79 years. The marked increase in positive ONCOblots in the 40 to 49 year old males was due to a disproportionate number of early prostate indications within this population, a number of which would likely never develop in overt disease. Otherwise, for all age groups, the observed incidence of cancer matched closely the incidences predicted from the National Cancer Institute Seer Cancer Statistics Review (Table 6) for between 10 and 20 years rather than the previous estimates of 7 to 10 years to be provided by the 2-D gel-western blot protocol lacking the NADH/functionalized linker modified version of the present invention consistent with the 2- to 3-fold increase in sensitivity of the test over that of the original test. The findings show that the 2-D gel-western blot test as described in the present invention has the potential to detect cancer earlier than any test previously reported. Certainly, not all of the early detected cancers would be expected to develop into clinically diagnosed disease but, based on the comparisons provided, in the order of 50% would have a high probability of so doing. At least with prostate cancer, positive ONCOblot results have been recorded for subjects with PSA values as low as 0.5 ng/ml in the age group of 40 to 49 year old males as one explanation for the exceptionally high incidence of cancer indicated by the functionalized ONCOblot test. It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method, kit, reagent, or composition of the invention, and vice versa. Furthermore, compositions of the invention can be used to achieve methods of the invention. It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims. All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects. As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. In embodiments of any of the compositions and methods provided herein, “comprising” may be replaced with “consisting essentially of” or “consisting of”. As used herein, the phrase “consisting essentially of” requires the specified integer(s) or steps as well as those that do not materially affect the character or function of the claimed invention. As used herein, the term “consisting” is used to indicate the presence of the recited integer (e.g., a feature, an element, a characteristic, a property, a method/process step or a limitation) or group of integers (e.g., feature(s), element(s), characteristic(s), propertie(s), method/process steps or limitation(s)) only. The term “or combinations thereof” as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof” is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context. As used herein, words of approximation such as, without limitation, “about”, “substantial” or “substantially” refers to a condition that when so modified is understood to not necessarily be absolute or perfect but would be considered close enough to those of ordinary skill in the art to warrant designating the condition as being present. The extent to which the description may vary will depend on how great a change can be instituted and still have one of ordinary skilled in the art recognize the modified feature as still having the required characteristics and capabilities of the unmodified feature. In general, but subject to the preceding discussion, a numerical value herein that is modified by a word of approximation such as “about” may vary from the stated value by at least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%. All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims. |
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