1. DNMT1-induced miR-378a-3p silencing promotes angiogenesis via the NF-κB signaling pathway by targeting TRAF1 in hepatocellular carcinoma
- Author
-
Jun-Jie Chen, Bin Zhu, Ying Feng, Jun-Ling Yang, Hua Huang, Wan-Jiang Xue, Wen Yuan Chung, and Yi-Lin Hu
- Subjects
DNA (Cytosine-5-)-Methyltransferase 1 ,Male ,Cancer Research ,Carcinoma, Hepatocellular ,Angiogenesis ,Down-Regulation ,Mice, Nude ,Transfection ,medicine.disease_cause ,Mice ,chemistry.chemical_compound ,Downregulation and upregulation ,medicine ,Animals ,Humans ,Gene silencing ,HCC ,RC254-282 ,Tube formation ,DNA methylation ,Research ,Liver Neoplasms ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Middle Aged ,miR-378a-3p ,Vascular endothelial growth factor ,TRAF1 ,TNF receptor associated factor ,Oncology ,chemistry ,Cancer research ,Carcinogenesis ,Chromatin immunoprecipitation ,Signal Transduction - Abstract
Background Angiogenesis plays an important role in the occurrence, development and metastasis of hepatocellular carcinoma (HCC). According to previous studies, miR-378a participates in tumorigenesis and tumor metastasis, but its exact role in HCC angiogenesis remains poorly understood. Methods qRT-PCR was used to investigate the expression of miR-378a-3p in HCC tissues and cell lines. The effects of miR-378a-3p on HCC in vitro and in vivo were examined by Cell Counting Kit-8 (CCK-8), Transwell, tube formation and Matrigel plug assays, RNA sequencing, bioinformatics, luciferase reporter, immunofluorescence and chromatin immunoprecipitation (ChIP) assays were used to detect the molecular mechanism by which miR-378a-3p inhibits angiogenesis. Results We confirmed that miR-378a-3p expression was significantly downregulated and associated with higher microvascular density (MVD) in HCC; miR-378a-3p downregulation indicated a short survival time in HCC patients. miR-378a-3p knockdown led to a significant increase in angiogenesis in vitro and in vivo. We found that miR-378a-3p directly targeted TNF receptor associated factor 1 (TRAF1) to attenuate NF-κB signaling, and then downregulated secreted vascular endothelial growth factor. DNA methyltransferase 1 (DNMT1)-mediated hypermethylation of miR-378a-3p was responsible for downregulating miR-378a-3p. Moreover, a series of investigations indicated that p65 initiated a positive feedback loop that could upregulate DNMT1 to promote hypermethylation of the miR-378a-3p promoter. Conclusion Our study indicates a novel DNMT1/miR-378a-3p/TRAF1/NF-κB positive feedback loop in HCC cells, which may become a potential therapeutic target for HCC.
- Published
- 2021