title: MicroRNA-122 plays a critical role in liver homeostasis and hepatocarcinogenesis.
abstract: MicroRNA-122 (miR-122), which accounts for 70% of the liver's total miRNAs, plays a pivotal role in the liver. However, its intrinsic physiological roles remain largely undetermined. We demonstrated that mice lacking the gene encoding miR-122a (Mir122a) are viable but develop temporally controlled steatohepatitis, fibrosis, and hepatocellular carcinoma (HCC). These mice exhibited a striking disparity in HCC incidence based on sex, with a male-to-female ratio of 3.9:1, which recapitulates the disease incidence in humans. Impaired expression of microsomal triglyceride transfer protein (MTTP) contributed to steatosis, which was reversed by in vivo restoration of Mttp expression. We found that hepatic fibrosis onset can be partially attributed to the action of a miR-122a target, the Klf6 transcript. In addition, Mir122a(-/-) livers exhibited disruptions in a range of pathways, many of which closely resemble the disruptions found in human HCC. Importantly, the reexpression of miR-122a reduced disease manifestation and tumor incidence in Mir122a(-/-) mice. This study demonstrates that mice with a targeted deletion of the Mir122a gene possess several key phenotypes of human liver diseases, which provides a rationale for the development of a unique therapy for the treatment of chronic liver disease and HCC.
authors: Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan.
authors: Wei-Chih
authors: WC
authors: Tsai
authors: Sheng-Da
authors: SD
authors: Hsu
authors: Chu-Sui
authors: CS
authors: Hsu
authors: Tsung-Ching
authors: TC
authors: Lai
authors: Shu-Jen
authors: SJ
authors: Chen
authors: Roger
authors: R
authors: Shen
authors: Yi
authors: Y
authors: Huang
authors: Hua-Chien
authors: HC
authors: Chen
authors: Chien-Hsin
authors: CH
authors: Lee
authors: Ting-Fen
authors: TF
authors: Tsai
authors: Ming-Ta
authors: MT
authors: Hsu
authors: Jaw-Ching
authors: JC
authors: Wu
authors: Hsien-Da
authors: HD
authors: Huang
authors: Ming-Shi
authors: MS
authors: Shiao
authors: Michael
authors: M
authors: Hsiao
authors: Ann-Ping
authors: AP
authors: Tsou
mesh_terms: D000818:Animals; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D005234:Fatty Liver / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D016147:Genes, Tumor Suppressor; D006706:Homeostasis; D006801:Humans; D050356:Lipid Metabolism / Q000235:genetics; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008106:Liver Cirrhosis, Experimental / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D008113:Liver Neoplasms / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000209:etiology / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D012727:Sex Characteristics
chemical_list: D008079:Lipoproteins, VLDL; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; C544354:Mirn122 microRNA, mouse