A Prelminary Study Of The Role Of GATA2 In Expression Of C-Myc In Prostate Cancer

Objective1. To investigate the expression level of GATA2 mRNA in benign prostate hyperplasia tissues and prostate cancer tissues and prostate cancer cells, respectively.Then analyze the association of GATA2 expression with clinicopathological variables of PCa. 2. To study whether GATA2 acts as a cofactor of AR to regulate the expression of c-Myc, resulting in the development of prostate cancer.MethodsRT-qPCR was used to examine the expression of GATA2 mRNA between BPH samples(n=80) and PCa samples(n=120) which had undergone radical prostatectomy at the second hosipital of Tianjin medical university from 2004 to 2014.No patient was preoperatively treated with radiotherapy, chemotherapy or androgen deprivation treatment. We studied the relationship between the expression of GATA2 mRNA and clinicopathological variables to assess its clinical significance. RT-qPCR and western blotting were applied in examining the expression of GATA2 mRNA and protein in prostate cancer cell lines including PC3, DU145,LNCaP,C4-2 and nontumorous prostatic epithelial cell lines RWPE-1. Then Immunoprecipitation was available for further verifying the interaction between GATA2 and AR.Lastly, we constructed the GATA2 shRNA and transduced it into LNCaP cell. Chromatin immunoprecipitation(ChIP) assay was used to evaluate whether the interaction between AR and c-Myc enhancer was decreasing,and whether the expression of HSPC111 protein, which is the downstream protein of c-Myc,was reducing followed by the low expression of GATA2.Results1.GATA2 mRNA was overexpressed in PCa tissues compared with BPH tissues(P<0.05). The enhanced expression of GATA2 was significantly associated with higher PSA(P<0.05), Gleason score(P<0.05), clinical stage(P<0.05) and lymph node invasion(P<0.05), however, not relevant to age, surgical margin status and seminal vesical invasion(P>0.05). Meanwhile, the expression of GATA2 mRNA and protein were higher in LNCa P and C4-2 cell than that in PC3 cell and DU145 cell. 2.GATA2 protein and AR protein could interact with each other in LNCaP and C4-2cell by Co-Immunoprecipitation. 3. The recruitment of AR to the c-Myc enhancer was significantly decreased and the expression of HSPC111 protein was reducing in shGATA2 transfected cells as compared with the control group.Conclusion1. The expression of GATA2 was up-regulated in PCa compared with those in BPH tissues, and the high-expression of GATA2 was involved in the tumorigenesis and development of prostate cancer. 2. GATA2 protein could act as a cofactor of AR protein to regulate the expression of c-Myc, promoting the development of PCa.