RESUMO
Long noncoding RNAs play an important role in the occurrence, invasion, as well as metastasis of various human cancers, including hepatocellular carcinoma. Long noncoding RNAs can affect the biological functions of hepatocellular carcinoma cells by regulating various genes; however, only a small fraction of molecular mechanisms of long noncoding RNAs have been elucidated. In the present study, lnc AC010973.1 (lnc-ATG9B-4) was first identified by microarray analysis from 8 patients with hepatocellular carcinoma and confirmed by quantitative PCR in 176 patients with hepatocellular carcinoma. We demonstrated that lnc-ATG9B-4 was tightly relative to the tumorous size, TNM stages, portal vein tumor thrombus (PVTT), the tumor capsule, metastasis, degree of differentiation, and poor prognosis of hepatocellular carcinoma according to long-term follow-up data. In hepatocellular carcinoma cells, overexpression of lnc-ATG9B-4 promoted proliferation, invasion, as well as migration, while inhibiting lnc-ATG9B-4 by siRNA significantly attenuated the proliferation, invasion, as well as migration. Interestingly, lnc-ATG9B-4 increased the expression of cyclin-dependent kinase 5 (CDK5), which was closely related to the development and chemotherapy sensitivity of hepatocellular carcinoma. In summary, our results revealed that lnc-ATG9B-4 suggests an unfavorable prognosis of hepatocellular carcinoma and facilitates the proliferation, invasion, as well as migration of hepatocellular carcinoma cells by upregulating CDK5. This research suggests that lnc-ATG9B-4 may be a new biomarker for predicting the prognosis of hepatocellular carcinoma; meanwhile, targeting lnc-ATG9B-4 might serve as a potential strategy for the treatment hepatocellular carcinoma.
Assuntos
Carcinoma Hepatocelular/genética , Movimento Celular/genética , Quinase 5 Dependente de Ciclina/genética , Progressão da Doença , Neoplasias Hepáticas/genética , RNA Longo não Codificante/metabolismo , Regulação para Cima/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Quinase 5 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , Invasividade Neoplásica , RNA Longo não Codificante/genética , Análise de SobrevidaRESUMO
Caspase-8 is an initiator of apoptotic signalling, and aberrations in procaspase-8 have been verified to be associated with malignant tumours. In previous studies, various procaspase-8 mutants were identified in AML patients, such as Q482H and M476W/Q482H mutations. The Q482H mutation can abolish caspase-8-mediated apoptosis by attenuating the dimerization of procaspase-8 protein monomers, causing AML patients carrying the Q482H mutation to develop resistance to chemotherapeutics. The patients with the M476W/Q482H mutation were sensitive to chemotherapy. Nevertheless, the underlying molecular mechanism is still unclear in regard to how the M476W/Q482H mutation restored caspase-8-mediated apoptosis. In this study, apoptosis was detected in the cells overexpressing the WT or mutant procaspase-8 with or without TRAIL treatment. Western blotting was devoted to detect the cleavage of procaspase-8 or the expression of proteins downstream in the apoptotic cascade and CO-IP was employed to analyze the dimerization of WT and mutant procaspase-8 proteins. Results demonstrated cells carrying the M476W/Q482H mutation restored caspase-8-mediated and TRAIL-induced apoptosis. The M476W/Q482H mutation recovered the dimerization of procaspase-8. Taken together, the M476W/Q482H mutation have restored caspase-8-mediated apoptosis resulting from the recovery of procaspase-8 dimerization.