Aim:To study the regulatory effects of 9-cis retinoic acid(RA)on the expression of human homeobox gene NKX3.1 in prostate cancer cell line LNCaP.Methods:Flow cytometry,reverse transcriptase polymerase chain reaction a...Aim:To study the regulatory effects of 9-cis retinoic acid(RA)on the expression of human homeobox gene NKX3.1 in prostate cancer cell line LNCaP.Methods:Flow cytometry,reverse transcriptase polymerase chain reaction and Western blotting were performed to evaluate the effects of 9-cis RA on NKX3.1 expression and cell cycle of LNCaP cells.To identify a regulatory region within the NKX3.1 promoter contributing to the regulation induced by 9-cis RA, we have constructed an NKX3.1 promoter-reporter plasmid,pGL_3-1040bp,and its 5′-deletion mutants,which were transfected into LNCaP cells with treatment of 9-cis RA in indicated concentrations.Results:With the treatment of 9-cis RA,the NKX3.1 promoter activity was increased in reporter gene assay and NKX3.1 expression was enhanced at both mRNA and protein levels in LNCaP cells.We found that the region between -936 and -921 in the upstream of NKX3.1 gene involved the inducible regulation by 9-cis RA treatment.In flow cytometry,9-cis RA treatment caused accumulation of cells in the G_1 phase of the cell cycle and a fewer cells pass through to G_2/M.Conclusion:Our results demonstrated that 9-cis RA as a differentiating agent can arrest prostate cancer cells in G_1 phase and reduce cell mitosis,and upregulate the expression of human homeobox gene NKX3.1,which is thought to play an important role in prostate differentiation and to act as a tumor suppressor gene in the prostate.(Asian J Androl 2006 Jul;8:435-441)展开更多
文摘Aim:To study the regulatory effects of 9-cis retinoic acid(RA)on the expression of human homeobox gene NKX3.1 in prostate cancer cell line LNCaP.Methods:Flow cytometry,reverse transcriptase polymerase chain reaction and Western blotting were performed to evaluate the effects of 9-cis RA on NKX3.1 expression and cell cycle of LNCaP cells.To identify a regulatory region within the NKX3.1 promoter contributing to the regulation induced by 9-cis RA, we have constructed an NKX3.1 promoter-reporter plasmid,pGL_3-1040bp,and its 5′-deletion mutants,which were transfected into LNCaP cells with treatment of 9-cis RA in indicated concentrations.Results:With the treatment of 9-cis RA,the NKX3.1 promoter activity was increased in reporter gene assay and NKX3.1 expression was enhanced at both mRNA and protein levels in LNCaP cells.We found that the region between -936 and -921 in the upstream of NKX3.1 gene involved the inducible regulation by 9-cis RA treatment.In flow cytometry,9-cis RA treatment caused accumulation of cells in the G_1 phase of the cell cycle and a fewer cells pass through to G_2/M.Conclusion:Our results demonstrated that 9-cis RA as a differentiating agent can arrest prostate cancer cells in G_1 phase and reduce cell mitosis,and upregulate the expression of human homeobox gene NKX3.1,which is thought to play an important role in prostate differentiation and to act as a tumor suppressor gene in the prostate.(Asian J Androl 2006 Jul;8:435-441)