title: MiR-122/cyclin G1 interaction modulates p53 activity and affects doxorubicin sensitivity of human hepatocarcinoma cells.
abstract: The identification of target genes is a key step for assessing the role of aberrantly expressed microRNAs (miRNA) in human cancer and for the further development of miRNA-based gene therapy. MiR-122 is a liver-specific miRNA accounting for 70% of the total miRNA population. Its down-regulation is a common feature of both human and mouse hepatocellular carcinoma (HCC). We have previously shown that miR-122 can regulate the expression of cyclin G1, whose high levels have been reported in several human cancers. We evaluated the role of miR-122 and cyclin G1 expression in hepatocarcinogenesis and in response to treatment with doxorubicin and their relevance on survival and time to recurrence (TTR) of HCC patients. We proved that, by modulating cyclin G1, miR-122 influences p53 protein stability and transcriptional activity and reduces invasion capability of HCC-derived cell lines. In addition, in a therapeutic perspective, we assayed the effects of a restored miR-122 expression in triggering doxorubicin-induced apoptosis and we proved that miR-122, as well as cyclin G1 silencing, increases sensitivity to doxorubicin challenge. In patients resected for HCC, lower miR-122 levels were associated with a shorter TTR, whereas higher cyclin G1 expression was related to a lower survival, suggesting that miR-122 might represent an effective molecular target for HCC. Our findings establish a basis toward the development of combined chemo- and miRNA-based therapy for HCC treatment.
authors: Dipartimento di Medicina Clinica e CRBA, Policlinico S.Orsola-Malpighi, Bologna, Italy.
authors: Francesca
authors: F
authors: Fornari
authors: Laura
authors: L
authors: Gramantieri
authors: Catia
authors: C
authors: Giovannini
authors: Angelo
authors: A
authors: Veronese
authors: Manuela
authors: M
authors: Ferracin
authors: Silvia
authors: S
authors: Sabbioni
authors: George Adrian
authors: GA
authors: Calin
authors: Gian Luca
authors: GL
authors: Grazi
authors: Carlo Maria
authors: CM
authors: Croce
authors: Simona
authors: S
authors: Tavolari
authors: Pasquale
authors: P
authors: Chieco
authors: Massimo
authors: M
authors: Negrini
authors: Luigi
authors: L
authors: Bolondi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002465:Cell Movement; D002470:Cell Survival; D056746:Cyclin G; D056766:Cyclin G1; D016213:Cyclins / Q000235:genetics* / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
chemical_list: D000903:Antibiotics, Antineoplastic; C534702:CCNG1 protein, human; C534703:Ccng1 protein, mouse; D056746:Cyclin G; D056766:Cyclin G1; D016213:Cyclins; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D034741:RNA, Small Interfering; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin