Negative regulation of cyclin D3 expression by trans- cription factor c-Etsl in umbilical cord hematopoietic cells  

作　　者：Fan-kai MENG Han-ying SUN Xi-you TAN Chun-rui LI Jian-feng ZHOU Wen-li LIU 

机构地区：[1]Department of Hematology, Tongji Hospital, Tongl＇i Medical College, Huazhong University of Science and Technology, Wuhan 430030,China

出　　处：《Acta Pharmacologica Sinica》2011年第9期1159-1164,共6页中国药理学报（英文版）

摘　　要：Aim： To investigate the role of transcription factor c-Etsl in cyclin D3 expression and its effects on the proliferation of umbilical cord hematopoietic cells. Methods： Cyclin D3 promoter deletion constructs were generated and transfected into CD34＋ cells. Dual luciferase reporter assays and TFSEARCH software were used to identify negative regulatory domains and to predict putative transcription factors involved in cyclin D3 downregulation. Expression of c-Etsl in CD34＋ cells was detected using electrophoretic mobility shift and super shift assays. Point mutants of c-Etsl binding sites were constructed. The wild-type c-Etsl and the mutant promoter constructs were co-transfected into CD34＋ cells to determine the promoter activity. The impact of c-Etsl expression on the proliferation of CD34＋ cells was assessed using M-R- assay. Results： Nine cyclin D3 promoter deletion constructs were generated. A negative regulatory domain containing c-Etsl binding sites was identified between -439 bp and -362 bp. Transfection of the promoter deletion constructs containing mutant c-Etsl binding sites enhanced cyclin D3 promoter activity. However, the opposite results were observed when CD34＋ cells were co-transfected with wildtype c-Etsl and its promoter deletion constructs. The overexpression of c-Etsl could suppress cyclin D3 mRNA and protein levels. In addi- tion, it inhibits the proliferation of CD34＋ cells. Conclusion： c-Etsl functions as a negative transcription factor, down-regulating the expression of cyclin D3, which leads to inhibition of CD34＋ cell proliferation.Aim： To investigate the role of transcription factor c-Etsl in cyclin D3 expression and its effects on the proliferation of umbilical cord hematopoietic cells. Methods： Cyclin D3 promoter deletion constructs were generated and transfected into CD34＋ cells. Dual luciferase reporter assays and TFSEARCH software were used to identify negative regulatory domains and to predict putative transcription factors involved in cyclin D3 downregulation. Expression of c-Etsl in CD34＋ cells was detected using electrophoretic mobility shift and super shift assays. Point mutants of c-Etsl binding sites were constructed. The wild-type c-Etsl and the mutant promoter constructs were co-transfected into CD34＋ cells to determine the promoter activity. The impact of c-Etsl expression on the proliferation of CD34＋ cells was assessed using M-R- assay. Results： Nine cyclin D3 promoter deletion constructs were generated. A negative regulatory domain containing c-Etsl binding sites was identified between -439 bp and -362 bp. Transfection of the promoter deletion constructs containing mutant c-Etsl binding sites enhanced cyclin D3 promoter activity. However, the opposite results were observed when CD34＋ cells were co-transfected with wildtype c-Etsl and its promoter deletion constructs. The overexpression of c-Etsl could suppress cyclin D3 mRNA and protein levels. In addi- tion, it inhibits the proliferation of CD34＋ cells. Conclusion： c-Etsl functions as a negative transcription factor, down-regulating the expression of cyclin D3, which leads to inhibition of CD34＋ cell proliferation.

关 键 词：transcription factor c-Etsl CYCLINS hematopoietic stem cells CD34~ cells gene regulation cell cycle point mutation 

分 类 号：Q813[生物学—生物工程] Q421