Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
Previous studies have suggested that microRNAs (miRNAs) may play important roles in tumorigenesis, but little is known about the functions of most miRNAs in cancer development. In the present study, we set up a cell-based screen using a luciferase reporter plasmid carrying the whole 4.7 kb 3¢-UTR of estrogen receptor a(ERa) mRNA cotransfected with a synthetic miRNA expression library to identify potential ERa-targeting miRNAs. | An estrogen receptor a suppressor microRNA-22 is downregulated in estrogen receptor a-positive human breast cancer cell lines and clinical samples Jianhua Xiong1 z Dianke Yu2 z Na Wei1 Hanjiang Fu3 Tianjing Cai1 Yuanyu Huang1 Chen Wu2 Xiaofei Zheng3 Quan Du1 Dongxin Lin2 and Zicai Liang1 1 Laboratory of Nucleic Acid Technology Institute of Molecular Medicine Peking University Beijing China 2 Department of Etiology and Carcinogenesis State Key Laboratory of Molecular Oncology Cancer Institute Chinese Academy of Medical Sciences and Peking Union Medical College Beijing China 3 Beijing Institute of Radiation Medicine China Keywords breast carcinoma estrogen receptor a microRNA-22 proliferation Correspondence Z. Liang Laboratory of Nucleic Acid Technology Institute of Molecular Medicine Peking University Beijing 100871 China Fax 86 10 62769862 Tel 86 10 62769862 E-mail liangz@pku.edu.cn Dongxin Lin Department of Etiology and Carcinogenesis Cancer Institute Chinese Academy of MedicalSciences Beijing 100021 China Fax 86 10 67722460 Tel 86 10 87788491 E-mail lindx72@cicams.ac.cn These authors contributed equally to this work Received 30 September 2009 revised 5 January 2010 accepted 25 January 2010 doi 10.1111 j.1742-4658.2010.07594.x Previous studies have suggested that microRNAs miRNAs may play important roles in tumorigenesis but little is known about the functions of most miRNAs in cancer development. In the present study we set up a cell-based screen using a luciferase reporter plasmid carrying the whole 4.7 kb 3 -UTR of estrogen receptor a ERa mRNA cotransfected with a synthetic miRNA expression library to identify potential ERa-targeting miRNAs. Among all the miRNAs miR-22 was found to repress robustly the luciferase signal in both HEK-293T and ERa-positive MCF-7 cells. Mutation of the target site was found to abrogate this repression effect of miR-22 whereas antagonism of endogenous miR-22 in MDA-MB-231 cells resulted in elevated reporter signals. We assessed the
