Tanshinone IIA Inhibits the Growth of LNCaP Cells by Blocking the Transcriptional Activity of Androgen Receptor

Abstract

Androgen receptor (AR) is a nuclear transcription factor of the hormone receptor family. For some prostate cancers, named AR-dependent prostate cancer, it plays an important role for the development and progress of prostate cancer. In this study, we showed 0.1μM tanshinone IIA can inhibit the expression of mRNA and protein level in AR downstream proteins. It suggests tanshinone IIA can block the transcriptional activity of activated ARs by lower concentration. We also showed tanshinone IIA can suppress stability of AR protein, but not the mRNA level of AR. We also found tanshinone IIA can inhibit the growth of LNCaP cells, AR-dependent prostate cancer cell line. This inhibitory effect is stronger on LNCaP cells stimulated by dihydrotestosterone (DHT) than without DHT, suggesting that tanshinone IIA can inhibit the growth of LNCaP cells through affecting the function of AR. In summary, we discovered tanshinone IIA can efficiently inhibit AR transactivation, block AR target genes expression in low concentration (0.1 μM), and then inhibit cell growth in AR positive LNCaP cells. Our results suggest that tanshinone IIA could be a potential agent for the treatment of prostate cancers.