title: Let-7 g microRNA sensitizes fluorouracil-resistant human hepatoma cells.
abstract: Let-7 microRNA is expressed in lower lever in a variety of human tumors and is involved in tumorigenesis. This study investigated the inhibitory effect of the let-7g microRNA on the expression of the HMGA2 gene in the fluorouracil (5-Fu)-resistant human hepatoma cell line Bel-7402/5-Fu, and the effect of let-7 g microRNA on drug sensitization in Bel-7402/5-Fu cells. Let-7 g microRNA and negative microRNA plasmids were constructed and transient transfected into Bel-7402/5-Fu cells. Expression levels of HMGA2 mRNA and protein in microRNA transient transfectants were clearly reduced as compared with negative microRNA transfectants and untreated cells. Flow cytometry revealed increased in S phase in let-7 g microRNA cells. dimethylthiazol-diphenyltetrazolium bromide (MTT) results indicated that microRNA transfectants had a higher cell inhibition rate than the negative vector or untreated cells after treatment with 0.13-13 microg/ml 5-Fu. In addition, cyclin A was down-regulated in the let-7 g transfectants cells.The results showed that let-7 g microRNA contributed to an increase of 5-Fu-induced cell cycle inhibit in human hepatoma cell and sensitized cells to 5-Fu, leading to increased the effectiveness of the drug in treating hepatoma cancer.
authors.forename: Huifang
authors.initials: H
authors.lastname: Tang
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Xiang
authors.forename: Jie
authors.initials: J
authors.lastname: Yin
authors.forename: Jia
authors.initials: J
authors.lastname: Yu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yang
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Lei
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy; D045744:Cell Line, Tumor; D004396:Coloring Agents; D019925:Cyclin A / Q000096:biosynthesis; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005434:Flow Cytometry; D005472:Fluorouracil / Q000494:pharmacology*; D005822:Genetic Vectors; D025743:HMGA2 Protein / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy; D035683:MicroRNAs / Q000494:pharmacology*; D060888:Real-Time Polymerase Chain Reaction; D013778:Tetrazolium Salts; D013844:Thiazoles; D014162:Transfection
chemical_list: D000964:Antimetabolites, Antineoplastic; D004396:Coloring Agents; D019925:Cyclin A; D025743:HMGA2 Protein; D035683:MicroRNAs; D013778:Tetrazolium Salts; D013844:Thiazoles; C487931:mirnlet7 microRNA, human; C022616:thiazolyl blue; D005472:Fluorouracil