Combination of navitoclax (Bcl-2 and Bcl-xL inhibitor) and Debio-0932 (Hsp90 inhibitor) suppresses the viability of prostate cancer cells via induction of apoptotic signaling pathway

Prostate cancer is one of the most common cancers in men. Given the diverse nature of prostate cancer and its tendency to respond differently to various treatments, combination therapies are often employed to enhance outcomes. In this study, the synergetic efficiency of chemotherapeutic drug Navitoclax and heat shock protein 90 (Hsp90) inhibitor Debio-0932 was evaluated in human prostate cancer cell line (PC3). Our results indicated that Navitoclax-Debio-0932 combination exhibited synergistic activity in PC3 cells at concentrations lower than IC 50 values. The combination of Navitoclax and Debio-0932 decreased PC3 cell viability in a dose dependent manner at 48 h. To investigate the apoptotic potential of the Navitoclax-Debio-0932 combination against prostate cancer cells, the mRNA and protein expression levels of apoptotic and antiapoptotic markers (Bax, Bcl-2, Bcl-xL, Cyt-c, Apaf-1, Casp-3, Casp-7, and Casp-9) were measured using RT-PCR and ELISA assay. Furthermore, the cleavage activity of Casp-3 was determined by colorimetric assay. The results revealed that Navitoclax-Debio-0932 combination potently induced intrinsic apoptotic pathway in PC3 cells rather than using drugs alone. The combined treatment of Navitoclax and Debio-0932 displayed synergistic cytotoxic and apoptotic effects on prostate cancer cells, presenting a promising approach for combination therapy in prostate cancer.