Differential profiling of prostate tumors versus benign prostatic tissues by using a 2DE-MALDI-TOF-based proteomic...

Oncoproteomic technologies offer a complementary approach to the understanding of cancer proteins' function and the translation of molecular knowledge into clinical practice. Our aim was to compare the proteomic profiles of prostate tumors versus benign prostatic hyperplasia (BPH) tissues in order to identify modulated proteins as the potential biomarkers for prostate cancer. Proteins extracted from twenty prostate cancer tissue specimens and ten BPH tissues were analyzed by two-dimensional electrophoresis (2-DE) coupled with MALDI-TOF mass spectrometry. Western blot and quantitative real-time PCR (RT-PCR) were performed to confirm the different amounts of protein biomarkers revealed by 2DE combined with MALDI mass spectrometry. We found 42 spots whose expression in the prostate was altered more than 1.5-fold compared with BPH tissue (p<0.05). These spots represented ten different proteins that were identified by a database search after mass spectrometry: they comprised proteins involved in the regulation of actin dynamics, the cytoskeleton, and cell motility (ACTG2, ACTA2, TPM1, DES, VIM, FLNA, and TAGLN), heat shock protein-27 (Hsp27), and proteins with other functions (TR and RANBP3). Subsequent western blot and RT-PCR assays for DES, VIM, TAGLN, and Hsp27 in prostate tumor tissues and BPH tissues confirmed the observations obtained by proteomic analysis. The cytoskeletal and cytoskeleton-associated proteins identified by this approach might be useful molecular targets for prostate cancer diagnostics and may contribute to novel therapies for prostate cancer.