tailieunhanh - Báo cáo khoa học: MicroRNA-23a promotes the growth of gastric adenocarcinoma cell line MGC803 and downregulates interleukin-6 receptor

MicroRNAs are an evolutionarily conserved class of endogenous noncod-ing RNAs that modulate gene expression at the post-transcriptional level. Recently, microRNA-23a (miR-23a) has been found to function as a growth-promoting and antiapoptotic factor in hepatocellular carcinoma cells. | MicroRNA-23a promotes the growth of gastric adenocarcinoma cell line MGC803 and downregulates interleukin-6 receptor Li-Hua Zhu1 2 Tao Liu1 Hua Tang1 Rui-Qing Tian1 Chang Su1 Min Liu1 and Xin Li1 1 Tianjin Life Science Research Center and Basic Medical School Tianjin MedicalUniversity Tianjin China 2 Department of Pathobiology Bioscience Faculty North China CoalMedicalCollege Tangshan China Keywords cell growth gastric adenocarcinoma IL6R miR-23a target gene Correspondence H. Tang Tianjin Life Science Research Center and Basic Medical School Tianjin MedicalUniversity Tianjin 300070 China Fax 86 22 23542503 Tel 86 22 23542503 E-mail htang2002@ These authors contributed equally to this work Received 11 April 2010 revised 15 June 2010 accepted 12 July 2010 MicroRNAs are an evolutionarily conserved class of endogenous noncoding RNAs that modulate gene expression at the post-transcriptional level. Recently microRNA-23a miR-23a has been found to function as a growth-promoting and antiapoptotic factor in hepatocellular carcinoma cells. Our previous study showed that miR-23a was significantly upregulat-ed in gastric adenocarcinoma tissues. In this study we found that miR-23a promoted the proliferative potential of gastric adenocarcinoma cell line MGC803. We also identified IL6R as a direct target gene for miR-23a using a fluorescent reporter assay. The mRNA and protein levels of IL6R were both inversely correlated with the miR-23a expression level. Our results demonstrate that miR-23a can target IL6R and promote the growth activity of gastric adenocarcinoma cells in vitro. The downregulation of IL6R by miR-23a may explain why the suppression of miR-23a can inhibit gastric cancer cell proliferation. doi Introduction Recent findings have shown that as regulation factors of gene expression microRNAs miRNAs are often overexpressed or downregulated in a number of human malignancies and some can also function as tumor suppressors or .