afimoxifene and bicalutamide

Bicalutamide (BIC) is an alternative treatment to castration for advanced prostate cancer. Breast events are common adverse effects which can be effectively prevented by the concurrent administration of tamoxifen, a selective estrogen receptor modulator.. We investigated the effects of BIC, 4-hydroxy Tamoxifen (4OHT), the active metabolite of tamoxifen, and their combination on the expression of a panel of genes implicated in prostate cancer development and progression in LNCaP cells stimulated with dihydrotestosterone.. Our findings confirm the anti-proliferative activity of BIC on LNCaP cell growth but also show the down-regulating function of this anti-androgen on the expression of genes involved in tumor proliferation and invasion [cyclins, caspases, epidermal growth factor (EGF)]. The combination with 4OHT exerts a synergistic effect on the downregulation of some genes involved in prostate cancer progression.. The observation that the expression of several genes [such as B-cell lymphoma-2 (BCL2), myelocytomatosis oncogene (MYC), caspases] is modulated midly-to-moderately, after 4OHT addition suggests that this combined approach in the clinical setting should be further investigated through appropriate trials.

Topics: Androgens; Anilides; Antineoplastic Combined Chemotherapy Protocols; Cell Growth Processes; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Humans; Kallikreins; Male; Neoplasms, Hormone-Dependent; Nitriles; Prostate-Specific Antigen; Prostatic Neoplasms; Tamoxifen; Tosyl Compounds

Bicalutamide (BIC) is widely used in prostate cancer therapy. The dose and schedule employed are well tolerated, but about 50% of patients develop gynecomastia. Several studies have shown a significant reduction of the troublesome effects when Tamoxifen is concomitantly administered with BIC. However, the results reported in the literature seem to be preliminary and possible interferences could be present. In order to clarify the molecular mechanisms of the combination of the two drugs, we have investigated whether the expression of the proteins belonging to nuclear matrix (NM), one modulator of hormone action, is altered by BIC and/or 4-hydroxy-tamoxifen (4OHT) in LNCaP cells. We focused above all on heterogeneous nuclear ribonucleoprotein K (hnRNP K) a NM protein with a key role in prostate carcinoma.. NM proteins were analyzed by two-dimensional gel electrophoresis. Modulation and compartmentalization of the androgen receptor and the hnRNP K were studied by Western blotting, confocal microscopy, and immunoprecipitation.. Proteomic analysis revealed that there is a similarity in the changes of the NM proteins elicited by drugs alone but that their combination does not result in a simple additive effect. Moreover, we found that in the nucleoplasm the androgen receptor and the hnRNP K colocalize in a complex that is highly proximal to DNA and that both proteins were synchronously modulated by BIC and/or 4OHT treatment.. This study confirm the pivotal role of hnRNP K in prostate carcinoma and suggest that this role might be played by the interaction with the androgen receptor.

Topics: Androgen Antagonists; Anilides; Cell Line, Tumor; Cell Nucleus; Cell Survival; Estrogen Antagonists; Heterogeneous-Nuclear Ribonucleoprotein K; Humans; Male; Nitriles; Phosphorylation; Prostate-Specific Antigen; Prostatic Neoplasms; Receptors, Androgen; Tamoxifen; Tosyl Compounds