Résumé
Abstract only 150 Background: Prostate cancer (PCa) is one of the leading causes of death from cancer in men. High Gleason grade prostate cancers are characterized by aggressive tumors with poorly differentiated cells and a high metastatic potential. They are often refractory to chemical castration but still treated with hormone therapy to which docetaxel or cabazitaxel are added when they become resistant to the anti-androgen. Despite many clinical trials with other chemotherapeutic agents, response rates remain low. Moreover, none of these trials took into account the tumor grade. Methods: We used an in silico approach to screen for drug candidates that could be used as an alternative to taxanes, based on a 86 genes signature which could distinguish between low-grade and high-grade tumors. We extracted from the NCI60 panel databases the expression profiles of the 86 genes across 60 human tumor cell lines and the corresponding in vitro cytotoxicity data of 152 drugs and looked for correlation between their expression level and cell sensitivity to each of these drugs. Results: Among the 86 genes, we identified 9 genes (PCCB, SHMT2, DPM1, RHOT2, RPL13, CD59, EIF4AI, CDKN2C, JUN) for which expression levels across the 60 cell lines was significantly correlated (p< 0.05) to oxaliplatin but not to cisplatin sensitivity. This signature was validated at the functional level since repression of each of these genes conferred a significant change in the sensitivity of PCa cell lines to oxaliplatin but not cisplatin. Conclusions: Our results provide a proof of concept that gene expression signature specific from high grade PCa could be used for the identification of alternative therapies to taxanes. They could also be used to select patients for further clinical trials and as predictive markers of response to these drugs, which represents a further step forward towards personalized therapy of PCa.