Mechanism study of dasatinib inhibiting phosphorylation of androgen receptor in prostatic cancer cells / 肿瘤研究与临床

ABSTRACT

Objective To investigate the mechanism of dasatinib,tyrosine kinase inhibitor,inhibiting androgen receptor (AR) phosphorylation in prostate cancer cells.Methods HEK-293T and COS7 cell lines were cotransfected by wild-type (WT)-AR,ARY267F or ARY534F with Ack1 or Src,respectively,and Western blot was used to detect the AR phosphorylation sites.LNCaP cells were treated by EGF or heregulin without androgen,then Western blot was used to detect AR phosphorylation.After these LNCaP cells were treated by dasatinib or transfection with siRNA to silence Ack1 or Src gene,Western blot was used to observe the effect on AR phosphorylation,and quantitative real-time reverse transcription polymerase chain (RT-PCR)was applied to detect PSA mRNA and hk2 mRNA.Results After transfection,Ack1 kinase mediated the phosphorylation of AR Tyr267 in HEK-293T cells,and Src mediated AR Tyr534 phosphorylation in COS7cells.When LNCaP cells were treated by heregulin,AR Tyr267 was phosphorylated,but its phosphorylation was inhibited after these cells were treated by dasatinib or ack1 gene was silenced.When LNCaP cells were treated by EGF,AR Tyr534 was phosphorylated,but its phosphorylation was inhibited after these cells were treated by dasatinib or Src gene was silenced.EGF or heregulin raised endogenous AR target gene,PSA and hK2,mRNA levels in LNCaP cells (P ＜ 0.05).However,after these cells were treated by dasatinib,PSA and hK2 mRNA levels induced by heregulin were decreased (P ＜ 0.05),but those induced by EGF PSA were no significant changes (P ＞ 0.05).Conclusion Dasatinib can inhibit AR Tyr267 and AR Tyr 534phosphorylation,and it may play a significant role in anti-prostate cancer cells by inhibiting Ack1-mediated AR Tyr-267 phosphorylation and the expression of PSA mRNA and hk2 mRNA induced by heregulin.