Dirty deeds done dirt cheap: sensitization of prostate cancer cells to abiraterone treatment using hydroxylated polychlorinated biphenyls

SummaryEffective targeting of androgen biosynthesis by the 17 α-hydroxylase/17,20-lyase inhibitor abiraterone prolongs survival in a variety of prostate cancer patients. However, resistance to abiraterone treatment occurs frequently and the development of new drugs supporting or complementing abiraterone therapy is urgently needed. We recently reported antipr oliferative and proapoptotic effects of hydroxylated polychlorinated biphenyls (PCBs) on various blood cell lines in vitro. Here we report the biological evaluation of the PCB28 derived OH-metabolites 3-OHCB28 or 3′-OHCB28 in prostate cancer cells. Depending on concentration, both metabolites inhi bit the growth of PC3 cells, a cell line representing later stages of advanced prostate cancer. In addition 3′-OHCB28 reduced the necessary concentration of abiraterone required for the inhibition of PC3 cells by a factor of 4. Western blot analysis of cytoprotective heatshock proteins (HSP) impli cated a significant reduction of HSP27 expression by 3′-OHCB28 in PC3 cells. Given the known HSP27 suppressive role of abiraterone, our results therefore suggest, that that the pharmacological interaction between abiraterone and 3′-OHCB28 in PC3 cells could be produced by the combined effect of both substances on the expression of HSPs, especially the expression of HSP27. Including the known dose response linkages and pharmacokinetic characteristics of the OH-metabolites described here, we conclude, that the use of hydroxylat...
Source: Investigational New Drugs - Category: Drugs & Pharmacology Source Type: research