RESUMO
Downregulation of deleted in liver cancer 1 (DLC1) is associated with poor prognosis of various cancers, but its functional mechanisms in hepatocellular carcinoma (HCC) remains unclear. In the present study, we investigated the roles of DLC1 in tumor progression and autophagy of HCC. We found that DLC1 was frequently downregulated in HCC tissues. Underexpression of DLC1 correlated with AFP level, vascular invasion, poor differentiation, and poor prognosis. In vitro assays revealed that DLC1 not only suppressed the proliferation, migration, and invasion of HCC cells, but also inhibited autophagy of HCC cells. Mechanistic investigation revealed that DLC1 decreased TCF4 expression and the interaction between ß-catenin and TCF4, then inactivated Wnt/ß-catenin signaling. Additionally, DLC1 suppressed the ROCK1 activity and the dissociation of the Beclin1-Bcl2 complex, thereby inhibiting autophagy of HCC cells. In conclusion, our findings imply that loss of DLC1 contributes to the progression and oncogenic autophagy of HCC.
Assuntos
Autofagia/genética , Carcinoma Hepatocelular/genética , Proteínas Ativadoras de GTPase/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Proteínas Supressoras de Tumor/genética , Animais , Carcinogênese/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas Ativadoras de GTPase/metabolismo , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Interferência de RNA , Terapêutica com RNAi/métodos , Carga Tumoral/genética , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Hepatocellular carcinoma (HCC) accounts for a large proportion of cancer-associated mortality worldwide. The functional impact of long noncoding RNAs (lncRNAs) in human cancer is not fully understood. Here, we identified a novel oncogenic lncRNA termed as lncPARP1, which was significantly up-regulated in HCC. Increase in lncPARP1 expression was associated with age, α-fetoprotein (AFP) levels, tumor size, recurrence, and poor prognosis of HCC patients. Loss-of-function approaches showed that knockdown of lncPARP1 inhibited proliferation, migration, and invasion, while induced apoptosis in HCC cells. Moreover, mechanistic investigation demonstrated that PARP1 was an underlying target of lncPARP1 in HCC. In summary, we provide the first evidence that lncPARP1 exerts an oncogene to promote HCC development and progression, at least in part, by affecting poly (ADP-ribose) (PAR) polymerase 1 (PARP1) expression.
Assuntos
Carcinogênese/genética , Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Poli(ADP-Ribose) Polimerase-1/genética , RNA Longo não Codificante/genética , Idoso , Animais , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Progressão da Doença , Feminino , Células Hep G2 , Xenoenxertos , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Camundongos Nus , Pessoa de Meia-Idade , Poli(ADP-Ribose) Polimerase-1/metabolismo , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Análise de SobrevidaRESUMO
Long noncoding RNAs (lncRNAs) are a new class of regulatory noncoding RNAs. Emerging evidences indicate that lncRNAs play a critical role in the development of hepatocellular carcinoma (HCC). Although several lncRNAs have been annotated, the association of most lncRNAs with HCC is unknown. In this study, we investigated lncRNA alterations in HCC by performing lncRNA microarray analysis. We identified a novel lncRNA called HCC-associated lncRNA (HCAL) that was highly expressed in HCC tissues. HCAL upregulation was clinically associated with poor differentiation, intravascular cancer embolus, and decreased survival of patients with HCC. HCAL silencing significantly inhibited the growth and metastasis of HCC cells both in vitro and in vivo. Interestingly, transcriptome-sequencing analysis of HCAL-knockdown cells showed alterations in some cancer-related pathways. Mechanistically, HCAL directly interacted with and functioned as a sponge for microRNAs such as miR-15a, miR-196a, and miR-196b to modulate LAPTM4B expression. Taken together, our findings suggest the presence of a novel lncRNA-miRNA-mRNA regulatory network, i.e., the HCAL-miR-15a/miR-196a/miR-196b-LAPTM4B network, in HCC and indicate that HCAL may be a potential target for treating HCC.
