1. microRNA-93-5p promotes hepatocellular carcinoma progression via a microRNA-93-5p/MAP3K2/c-Jun positive feedback circuit
- Author
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Tao-Tao Liu, Asha Balakrishnan, Xiang-Nan Yu, Ling Dong, Guang-Cong Zhang, Hong-Ying Guo, Ji-Min Zhu, Guangqi Song, Michael Ott, Jialei Sun, Hai-Rong Zhu, Xuan Shi, Xizhong Shen, Enkhnaran Bilegsaikhan, and Shuqiang Weng
- Subjects
0301 basic medicine ,Cancer Research ,Three prime untranslated region ,c-jun ,RNA activation ,MAP3K2 ,Biology ,digestive system diseases ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Downregulation and upregulation ,030220 oncology & carcinogenesis ,microRNA ,Gene expression ,Genetics ,Cancer research ,Protein kinase A ,Molecular Biology - Abstract
Cumulative evidence suggests that microRNAs (miRNAs) promote gene expression in cancers. However, the pathophysiologic relevance of miRNA-mediated RNA activation in hepatocellular carcinoma (HCC) remains to be established. Our previous miRNA expression profiling in seven-paired HCC specimens revealed miR-93-5p as an HCC-related miRNA. In this study, miR-93-5p expression was assessed in HCC tissues and cell lines by quantitative real-time PCR and fluorescence in situ hybridization. The correlation of miR-93-5p expression with survival and clinicopathological features of HCC was determined by statistical analysis. The function and potential mechanism of miR-93-5p in HCC were further investigated by a series of gain- or loss-of-function experiments in vitro and in vivo. We identified that miR-93-5p, overexpressed in HCC specimens and cell lines, leads to poor outcomes in HCC cases and promotes proliferation, migration, and invasion in HCC cell lines. Mechanistically, rather than decreasing target mRNA levels as expected, miR-93-5p binds to the 3'-untranslated region (UTR) of mitogen-activated protein kinase kinase kinase 2 (MAP3K2) to directly upregulate its expression and downstream p38 and c-Jun N-terminal kinase (JNK) pathway, thereby leading to cell cycle progression in HCC. Notably, we also demonstrated that c-Jun, a downstream effector of the JNK pathway, enhances miR-93-5p transcription by targeting its promoter region. Besides, downregulation of miR-93-5p significantly retarded tumor growth, while overexpression of miR-93-5p accelerated tumor growth in the HCC xenograft mouse model. Altogether, we revealed a miR-93-5p/MAP3K2/c-Jun positive feedback loop to promote HCC progression in vivo and in vitro, representing an RNA-activating role of miR-93-5p in HCC development.
- Published
- 2020