Long Noncoding RNA HOST2 Promotes Epithelial-Mesenchymal Transition, Proliferation, Invasion and Migration of Hepatocellular Carcinoma Cells by Activating the JAK2-STAT3 Signaling Pathway.

BACKGROUND/AIMS: This study aims to examine the effect of long noncoding RNA HOST2 (LncRNA HOST2) on epithelial-mesenchymal transition (EMT), proliferation, invasion and migration of hepatocellular carcinoma (HCC) cells via activation of the JAK2-STAT3 signaling pathway.

METHODS: HCC and para-cancerous tissues were collected from 136 HCC patients. Immunohistochemistry was used to detect the expression of JAK2 and STAT3. HCC SMMC7721 cells were grouped into blank, negative control (NC), HOST2 mimic and HOST2 inhibitor groups. The mRNA and protein expression levels of HOST2, JAK2, STAT3, E-cadherin, vimentin, Snail, Slug, Twist and Zeb1 in tissues and cells were determined by reverse transcription -quantitative polymerase chain reaction (RT-qPCR) and Western blotting, respectively. An MTT assay, scratch test and Transwell assay were applied to measure cell proliferation, migration and invasion, respectively.

RESULTS: The levels of JAK2, STAT3 and vimentin were higher in HCC tissues, while the expression of E-cadherin was lower in HCC tissues compared with para-cancerous tissues. The silencing of HOST2 significantly decreased cell proliferation, migration and invasion, reduced the levels of HOST2, JAK2, STAT3 and vimentin, and elevated the expression of E-cadherin. HOST2 silencing also decreased the levels of Snail, Slug and Twist but increased the level of Zeb1 protein, while the opposite findings were observed in the HOST2 mimic group.

CONCLUSION: These results reveal a possible mechanism in HCC in which LncRNA HOST2 may increase EMT and enhance proliferation, invasion and metastasis of HCC cells via activation of the JAK2-STAT3 signaling pathway.