ABSTRACT
We aimed to investigate the role of methyltransferase-like 3 (METTL3) in regulating HCC by mediating m6A level of ubiquitin-specific protease (USP7). METTL3 levels and m6A contents in HCC tissues and cells were detected. Potential correlations between METTL3 level and lymphatic metastasis, tumor size, tumor staging, and overall survival of HCC patients were analyzed. Moreover, its regulatory effects on proliferative, migratory, and invasive rates of HCC cells were examined. Potential methylation of USP7 in HCC was predicted using an online software, and the correlation between USP7 and METTL3 was assessed. METTL3 and m6A were increased both in HCC cells and tissues. High level of METTL3 was associated with the incidence of lymphatic metastasis, large tumor size, advanced tumor staging, and low overall survival of HCC. Silencing of METTL3 reduced proliferation, migration, and invasion rates. USP7 was predicted to have a methylation site regulated by METTL3. It was upregulated in HCC and associated with METTL3 level positively. USP7 silencing decreased proliferation, migration, and invasion rates of HCC cells. METTL3 promotes HCC to proliferate, migrate, and invade by regulating m6A methylation of USP7.
ABSTRACT
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most severe malignant cancers that leads to high death rate worldwide. Recent research revealed that long non-coding RNAs (lncRNAs) exert a critical role regarding chemoresistance in numerous cancers, including HCC. OBJECTIVES: Our research aimed to explore the function and molecular mechanism of lncRNA PCGEM1 on oxaliplatin resistance of HCC in vitro. MATERIAL AND METHODS: Expression of the lncRNA PCGEM1, together with miR-129-5p, and the mRNA level of ETV1 and drug resistance-related genes including LRPA, MDR1 and MDR3 were determined using quantitative real-time polymerase chain reaction (qRT-PCR) in an oxaliplatin-resistant HCC cell line (Hep3B/OXA). Cell Counting Kit-8 (CCK-8) was employed to assess the viability and cell survival rate, and transwell assays were performed to measure the number of migrated or invaded cells. In addition, the relation among lncRNA PCGEM1, miR-129-5p and ETV1 were determined using luciferase assay. RESULTS: Our data indicated that PCGEM1 and ETV1 expression were enhanced in Hep3B/OXA cells. Furthermore, knockdown of lncRNA PCGEM1 significantly decreased the migration, invasion and mRNA expressions of LRPA, MDR1 and MDR3, and the cell viability in Hep3B/OXA cells. The starBase online tool and luciferase assays verified that miR-129-5p targeted PCGEM1 and ETV1, signifying that PCGEM1 could enhance ETV1 expression via suppressing miR-129-5p. CONCLUSIONS: Our findings demonstrated that PCGEM1 modulated oxaliplatin resistance by targeting the miR-129-5p/ETV1 pathway in HCC in vitro, suggesting a potential strategy for the treatment of chemoresistant HCC.
Subject(s)
Carcinoma, Hepatocellular , Drug Resistance, Neoplasm , Liver Neoplasms , MicroRNAs , RNA, Long Noncoding , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Cell Line, Tumor , Cell Movement , Cell Proliferation , DNA-Binding Proteins , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , MicroRNAs/genetics , Oxaliplatin/pharmacology , RNA, Long Noncoding/genetics , Transcription FactorsABSTRACT
To explore the role of POTEE in the malignant development of pancreatic cancer and the possible mechanism. POTEE levels in pancreatic cancer samples were detected. The relationship between POTEE level and clinical data of pancreatic cancer patients was analyzed. After knockdown of POTEE or treatment of the GSK-3ß inhibitor, proliferative change in pancreatic cancer cells was assessed. Protein levels of vital genes in the PI3K/Akt/GSK-3ß/ß-catenin signaling influenced by POTEE were examined. POTEE was upregulated in pancreatic cancer samples. High level of POTEE indicated advanced tumor staging, large tumor size, and poor prognosis in pancreatic cancer patients. Knockdown of POTEE or treatment of Tideglusib remarkably attenuated proliferative ability in pancreatic cancer cells. Vital genes in the PI3K/Akt/GSK-3ß/ß-catenin signaling were downregulated by knockdown of POTEE. POTEE stimulates the proliferative ability in pancreatic cancer by activating the PI3K/Akt/GSK-3ß/ß-catenin signaling. High level of POTEE indicates advanced tumor staging, large tumor size and poor prognosis in pancreatic cancer patients.
