RESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) is the most predominant primary liver cancer. Extracellular vesicles (EV)-mediated microRNA (miRNA) delivery is critical in cancer metastasis. We aimed to identify the mechanism of HCC cell-derived EVs-mediated miR-3129 in HCC. METHODS: After EVs isolation and identification, miR-3129 expression in plasma EVs was evaluated and its diagnostic efficiency was analyzed. miR-3129 inhibitor was transfected into HepG2 and SMMC7721 cells, and cell malignant episodes were assessed. HCC cells were incubated with EVs from MHCC-97H cells and transfected with miR-3129 inhibitor and/or TXNIP. The nude mice were injected with MHCC-97H cells-EV or MHCC-97H cells-EV/miR-3129 inhibitor, and HCC growth and metastasis were assessed. RESULTS: miR-3129 was highly expressed in plasma EVs from HCC patients, which was the essential diagnostic biomarker for HCC. miR-3129 downregulation inhibited the malignant episodes of HCC cells. MHCC-97H cell-EVs were absorbed by HCC cells and transferred miR-3129 to HCC cells. EVs-carried miR-3129 promoted malignant episodes of HCC cells, which were weakened by miR-3129 inhibition in EVs. miR-3129 targeted TXNIP. TXNIP overexpression averted the effect of EVs-carried miR-3129 in HCC. In vivo, MHCC-97H cell-EVs transferred miR-3129 to facilitate HCC growth and metastasis. CONCLUSION: MHCC-97H cell-EVs transferred miR-3129 to promote HCC metastasis by targeting TXNIP.
Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Transporte/genética , Vesículas Extracelulares/metabolismo , Neoplasias Hepáticas/genética , MicroRNAs/genética , Animais , Carcinoma Hepatocelular/patologia , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Several microRNAs (miRNAs) have been reported as oncogenes or tumor suppressors in many cancers, including gastric cancer (GC). However, the role and molecular mechanism of miR-3129 in GC is largely unknown. We aimed to explore the function and the underlying molecular mechanism of miR-3129 in GC. Cancer tissues and corresponding adjacent tissues were collected from 50 patients with GC, and the expression of miR-3129 was detected by RT-qPCR. The expression of miR-3129 and pRb in human GC cell line SCG7091 was altered by transient transfection. Thereafter, MTT and flow cytometry assays were used to analyze cell viability and cell cycle. The expression of cyclin E, CDK2, CDK2 inhibitors (p16 and 21), and pRb were detected by RT-qPCR and western blot. A significant up-regulation of miR-3129 was observed in GC tissues compared to adjacent tissues. Overexpression of miR-3129 significantly improved cell viability after 4 days of post-transfection. Flow cytometry assay results showed that the miR-3129 overexpression arrested more SGC7901 cells at S phase. Moreover, overexpression of miR-3129 down-regulated the expression of CDK2 inhibitors while it up-regulated the expression levels of cyclin E, CDK2, and pRb. Interestingly, we found that pRb inhibition reversed the effect of miR-3129 inhibitor on cell proliferation in SGC7901 cells, increased cell viability, reduced cells at G0/1 phase, and modulated the expression of proliferation-related factors. Our results revealed that miR-3129 functioned as an oncogene through positive regulation of pRb and may prove to be a promising option for molecular therapy of GC.
