2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

Biochip-Based Test System for Cancer Diagnostics. Simultaneous Quantitation of Total and Free Forms of Prostate-Specific Antigen

T. Osipova, Z. Sokolova, T. Ryabykh, V. Karaseva, M. Modorsky, V. Matveev, A. Baryshnikov
N.N. Blokhin Cancer Research Center, RAMS, RU

protein biochip, cancer diagnostics, PSA, PSAt, PSAf, ROC-analysis

Background. Prostate-specific antigen (PSA) is the most useful marker for the early detection of prostate cancer (PCa). The use of two PSA forms – total (PSAt) and free (PSAf) makes it possible to differentiate benign prostatic hyperplasia (BPH) from PCa. The biochip-based test-system permits simultaneous quantitation of PSAt and PSAf (Osipova et al., 2006). The goal of the investigation is diagnostic performance evaluation of the biochip-based test system for two PSA forms and its comparison to efficacy of ELISA test-system (CanAg). Materials and methods. Gel-based microchips with immobilized monoclonal antibodies to two forms of tumor antigen were manufactured in Biochip center of EIMB RAS. PSAt and PSAf concentrations were determined in sandwich immunoassay with fluorescence detection. Sera were collected from 63 patients with PCa, 48 patients with BPH, 38 patients with urogenital malignant tumors (UMT) and 22 healthy donors. Three models were formed: PCa versus normal healthy controls, PCa versus UMT, and PCa versus BPH. The computer program MedCalc was used for ROC curve analysis. Results. Regression analysis has revealed a high degree of correlation (r=0,96; p0.05) for each of the models: PCa/ healthy donors, PCa/ UMT and PCa/BPH. Conclusion. Diagnostic performance of the biochip-based test system for quantitative determination of total and free forms of PSA is highly competitive with that of ELISA test-system (CanAg). The advantage of biochip-based test system is simultaneous determination of both markers. This new test-system can be applied to PCa diagnostics in group of high risk (men older than 45). Key words: protein biochip, cancer diagnostics, PSA, PSAt, PSAf, ROC-analysis a) b) Figure 1: Linear regression analysis of the results of PSAt (a) and PSAf (b) measurements in biochip-based test-system and in CanAg test-system

Nanotech 2008 Conference Program Abstract