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Background/aim: Autoantibodies have potential as circulating biomarkers for early cancer detection. This study aimed to screen for known autoantibodies in human plasma using an Autoantibody Profiling System (APS) and quantify the levels in plasma of donors with/without breast cancer., Materials and Methods: Plasma from nine female donors diagnosed with breast cancer (test group) and nine matched donors with no personal history of cancer (reference group) were screened with an APS containing probes for 30 autoantibodies. Autoantibody levels ≥1.5 times the mean concentration of the group were considered elevated, and test/reference ratios ≥1.3 were considered higher in the test group compared to the reference group., Results: Twenty percent of the probes detected elevated levels of autoantibodies against proteins involved in different cancer mechanisms. Amongst these, the levels of autoantibodies against interleukin 29 (IL29), osteoprotegerin (OPG), survivin (SUR), growth hormone (GRH) and resistin (RES) were significantly higher in the cancer group compared to the reference group (p<0.05), whereas the level of autoantibody against cytotoxic T-lymphocyte associated antigen-4 (CTLA4) was not significantly different between the two groups (p=0.38)., Conclusion: Disease-relevant autoantibodies were detected in the plasma of patients with breast cancer and donors without breast cancer. This means that identifying the type and level of autoantibodies in samples will be important in determining their significance in the disease process. A microtiter plate-based array system could be a fast and inexpensive screening method for identifying and quantifying autoantibodies in human plasma., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: The ability to easily detect autoantibodies will help in the early diagnosis and treatment of certain diseases. Currently, available methods for autoantibody detection are time-consuming and cumbersome. The present study aimed to evaluate the performance of an easy-to-use antigen array developed for autoantibody detection., Materials and Methods: Plasma from 9 female donors diagnosed with ovarian cancer (test group) and 9 matched donors with no history of cancer (reference group) were screened and results were compared. Autoantibody levels ≥1.5-times the background were classified as positive., Results: A total of 29 autoantibodies were detected, out of which the autoantibody against osteoprotegerin was found to be significantly higher in the "test" group (p<0.001) while those against macrophage migration inhibitor factor, interleukin-2 and vascular endothelial growth factor were lower (p<0.05)., Conclusion: The evaluated antigen array has potential as a simple method for determining the presence/absence of up to 90 disease-associated autoantibodies in a plasma specimen., (Copyright© 2016, International Institute of Anticancer Research (Dr. John G. Delinasios), All rights reserved.)

Epidemiological and preclinical studies suggest that environmental factors, hormonal responses and lifestyle, including diet and physical inactivity, are likely contributors to the initiation and progression of prostate cancer in humans. Although the effects of the food derived carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and/or testosterone (T) in the development of prostate cancer in the rat have been reported, the extent to which such compounds impact cancer related proteins is not clear. Knowledge of cancer-related proteins impacted by PhIP and/or T is prerequisite to developing novel strategies to early-detect prostate cancer. Male F344 rats were sacrificed, the prostate tissue isolated and separated into dorsolateral, ventral, and anterior lobes. The lobes were cultured and treated with 10(-3) M NHPhIP and/or 10(-7) M DT for 24 h. NHPhIP is the genotoxic form of PhIP and DT is the more proliferative form of T. We used 2D-DIGE and LC/MS/MS technologies to study the proteome of the prostate lobes to determine if the compounds will trigger detectable changes in expression of cancer-related proteins. Analysis of the signals from 2D-DIGE revealed that about 10% of proteins were differentially expressed in the NHPhIP and/or DT treatments compared to controls. Eight candidate protein spots detected by 2D-DIGE in at least two out of three lobes showed > or =2-fold difference between treated and control samples. Five out of the eight spots contained single proteins; including, phospholipase Calpha (PLP-Calpha), Rab7, SAR1a, ribosomal protein S7 (RPS7), and nucleoside diphosphate kinase (NDPK). A survey of the literature shows that NDPK expression is altered in human cancers, including prostate cancer. Thus, we validated the altered expression of NDPK by Western blot analysis. The concordance between 2D-DIGE and Western blot analysis was 80%. The results of this study demonstrate, for the first time, that the combination of 2D-DIGE and LC/MS/MS is a powerful tool for identification of proteins in the prostate tissue that are altered by environmental carcinogens and/or hormones.

Proteomics is now widely employed in the study of cancer. Many laboratories are applying the rapidly emerging technologies to elucidate the underlying mechanisms associated with cancer development, progression, and severity in addition to developing drugs and identifying patients who will benefit most from molecular targeted compounds. Various proteomic approaches are now available for protein separation and identification, and for characterization of the function and structure of candidate proteins. In spite of significant challenges that still exist, proteomics has rapidly expanded to include the discovery of novel biomarkers for early detection, diagnosis and prognostication (clinical application), and for the identification of novel drug targets (pharmaceutical application). To achieve these goals, several innovative technologies including 2-D-difference gel electrophoresis, SELDI, multidimensional protein identification technology, isotope-coded affinity tag, solid-state and suspension protein array technologies, X-ray crystallography, NMR spectroscopy, and computational methods such as comparative and de novo structure prediction and molecular dynamics simulation have evolved, and are being used in different combinations. This review provides an overview of the field of proteomics and discusses the key proteomic technologies available to researchers. It also describes some of the important challenges and highlights the current pharmaceutical and clinical applications of proteomics in human cancer research., (Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Capillary array electrophoresis and laser-assisted microdissection, which provide increased speed and accuracy in loss of heterozygosity studies, are often used independently in studying breast cancer; the successful coupling of these emerging technologies, however, must overcome technical problems, especially those related to the poor quality and quality of DNA typically retrieved from archival tumor samples. Here we present a panel of 52 microsatellite markers from 26 of the most commonly deleted regions in breast cancer. All markers have been optimized to robustly amplify DNA extracted from paraffin-embedded samples, represent informative (highly polymorphic) loci, and effectively detect chromosomal loss. In the 10 tumor samples (stage 0 to stage III) tested here, chromosomal loss was detected loss for every locus, and the degree of loss at the 26 commonly deleted regions ranged from 23% to 77%. This panel can be used to quickly detect genomic patterns of loss in large numbers of breast tumor samples and may provide both clinical information and molecular information regarding the underlying tumor suppressor genes.