There is currently no definitive cure for metastatic castration-resistant prostate cancer (mCRPC) In this study, we investigated the possible anticancer effects of two nucleoside antibiotics: puromycin and blasticidin. PC3 cells were significantly more susceptible to both antibiotics compared to DU145 cells.
There is currently no definitive cure for metastatic castration-resistant prostate cancer (mCRPC), therefore justifying the incessant need for more investigative studies to either repurpose old drugs or identify novel and effective therapeutics. In this study, we investigated the possible anticancer effects of two nucleoside antibiotics: puromycin and blasticidin. We hypothesized that the two antibiotics alone or combined with other drugs will inhibit prostate cancer (PCa) cell proliferation and metastasis and induce cell death via apoptosis. mCRPC cell lines (PC3 and DU145) with different p53-gene statuses were cultured and seeded in 96 well-plates, and thereafter treated with varying concentrations of puromycin and blasticidin (1 ng/mL - 100 g/mL) for 24 - 48 hours. Resazurin reduction and/or MTT assays were done to evaluate the treatment-induced effects on mCRPC cell viability and proliferation. The colony-forming assay measured the cell survival rate following treatment nucleoside antibiotics while scratch migration assay and dual-fluorescent microscopy assessed the effects on metastatic potential and cell death, respectively. The two antibiotics were combined with either paclitaxel, docetaxel, or cabazitaxel to check for synergism. Our results indicate that both antibiotics exhibit dose- and time-dependent anticancer effects on growth, survival, and metastasis of mCRPCs. PC3 cells were significantly more susceptible to both antibiotics compared to DU145 cells. Both cell lines were more susceptible to puromycin compared to blasticidin. Synergism was observed when each antibiotic compound was combined with any of the three taxanes. In conclusion, we have demonstrated that both puromycin and blasticidin could be explored for the treatment of mCRPC.