MicroRNA-122 inhibits tumorigenic properties of hepatocellular carcinoma cells and sensitizes these cells to sorafenib.
MicroRNAs are negative regulators of protein coding genes. The liver-specific microRNA-122 (miR-122) is frequently suppressed in primary hepatocellular carcinomas (HCCs). In situ hybridization demonstrated that miR-122 is abundantly expressed in hepatocytes but barely detectable in primary human HCCs. Ectopic expression of miR-122 in nonexpressing HepG2, Hep3B, and SK-Hep-1 cells reversed their tumorigenic properties such as growth, replication potential, clonogenic survival, anchorage-independent growth, migration, invasion, and tumor formation in nude mice. Further, miR-122-expressing HCC cells retained an epithelial phenotype that correlated with reduced Vimentin expression. ADAM10 (a distintegrin and metalloprotease family 10), serum response factor (SRF), and insulin-like growth factor 1 receptor (Igf1R) that promote tumorigenesis were validated as targets of miR-122 and were repressed by the microRNA. Conversely, depletion of the endogenous miR-122 in Huh-7 cells facilitated their tumorigenic properties with concomitant up-regulation of these targets. Expression of SRF or Igf1R partially reversed tumor suppressor function of miR-122. Further, miR-122 impeded angiogenic properties of endothelial cells in vitro. Notably, ADAM10, SRF, and Igf1R were up-regulated in primary human HCCs compared with the matching liver tissue. Co-labeling studies demonstrated exclusive localization of miR-122 in the benign livers, whereas SRF predominantly expressed in HCC. More importantly, growth and clonogenic survival of miR-122-expressing HCC cells were significantly reduced upon treatment with sorafenib, a multi-kinase inhibitor clinically effective against HCC. Collectively, these results suggest that the loss of multifunctional miR-122 contributes to the malignant phenotype of HCC cells, and miR-122 mimetic alone or in combination with anticancer drugs can be a promising therapeutic regimen against liver cancer.
Bai
Shoumei
S
Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA.
Nasser
Mohd W
MW
Wang
Bo
B
Hsu
Shu-Hao
SH
Datta
Jharna
J
Kutay
Huban
H
Yadav
Arti
A
Nuovo
Gerard
G
Kumar
Pawan
P
Ghoshal
Kalpana
K
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001557:Benzenesulfonates / Q000494:pharmacology*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D017403:In Situ Hybridization; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000502:physiology*; D009536:Niacinamide / Q000031:analogs & derivatives; D010671:Phenylurea Compounds; D011725:Pyridines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077157:Sorafenib; D014162:Transfection
D000970:Antineoplastic Agents; D001557:Benzenesulfonates; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D010671:Phenylurea Compounds; D011725:Pyridines; D012333:RNA, Messenger; D009536:Niacinamide; D000077157:Sorafenib; D008156:Luciferases