SerpinA1:a Predictor For Treatment Sensitivity In Prostate Cancer Hormonal Therapy

[Objectives] To apply serine protease inhibitor Al (serpin Al) for the most differentially expressed protein screened in blood in prostate cancer (PCa) patients with different sensitivity to hormonal therapy, and evaluate the validity and accuracy of Serpin Al in predictinghormonal treatment sensitivity at different levels in vitro and in vivo, with an attempt to provide theoretical guidance for personalized treatment in PCahormonal therapy.[Methods] 1) Twenty PCa patients with progression time to hormonal resistance<6 months (low treatment sensitivity) and 20 with progression time>24 months (high treatment sensitivity), were included in the present study. iTRAQ-based quantitative proteomic analysis was applied for screening of differentially expressed proteins in PCa patient blood, and Serpin Al was administered for the most differentially expressed ones according to spectrometry results.2) PCa cell lines with different hormone dependence were collected and cultured. Serpin Al mRNA expressionwas determined by RT-PCR, protein expression was determined by Western-blot. Supernatant serpin Al level in different PCa cell lines were determined by ELISA. Transurethral prostate resection and blood specimen were collected, and serpin Al expression in tissue and blood was determined by immunohistochemistry and ELISA[Results] Stable PCa cell lines with different hormone dependence were cultured. RT-PCR and Western Blot indicated that Serpin Al mRNA and protein in hormone independen PCa cell lines were higher than that in hormone dependent PCa cell lines; Serpin Al was proven exist in supernatant in different PCa cell lines, thus indicating it as a secretory protein; in transurethral prostate resection specimen, serpin Al level was higher in high treatment sensitivity PCa patients; serpin Al levels in high and low treatment sensitivity patients was determined.[Conclusions] Our results suggest that serpin Al is related to treatment sensitivity in PCa patients, and serpin Al may serve as a potential biomarker to predict hormonal response in PCa patients.