Long noncoding RNA HNF1A-AS1 promotes ovarian cancer growth and M2 macrophage polarization by counteracting miR-214-mediated suppression of semaphorin 4D signaling

To determine whether lncRNA HNF1A-AS1 affects epithelial ovarian cancer (EOC) growth and macrophage polarization through miR-214/SEMA4D, the endogenous HNF1A-AS1 and miR-214 levels in human EOC cell lines are compared with those in normal ovarian epithelial IOSE80 cells. <i>HNF1A-AS1</i> is overexpressed or silenced to investigate whether HNF1A-AS1 regulates miR-214/SEMA4D in SKOV3 cells and xenograft tumors, as well as the phenotypic switching of THP-1 cells. Compared with IOSE80 cells, EOC cells present significantly higher HNF1A-AS1 level and lower miR-214 level. Fluorescence <i>in situ</i> hybridization reveals predominant cytoplasmic localization of HNF1A-AS1, supporting its role as a competing endogenous RNA. HNF1A-AS1 and miR-214 antagonize each other in SKOV3 cells. <i>In vitro</i>, HNF1A-AS1 inhibits SKOV3 apoptosis and promotes migration and invasion. HNF1A-AS1 overexpression enhances miR-214 downstream of SEMA4D/PLEXIN-B1/TIAM1/RAC signaling, but miR-214 mimics significantly reverses this effect. Compared with control tumors, xenograft tumors derived from HNF1A-AS1-overexpressing SKOV3 cells present increased tumor growth, attenuated miR-214 expression, and activated SEMA4D/PLEXIN-B1/TIAM/RAC signaling. Knockdown of <i>HNF1A-AS1</i> has the opposite effects. Additionally, HNF1A-AS1 promotes M2 phenotypic switching in THP-1 cells, which could be reversed by miR-214 overexpression or <i>SEMA4D</i> silencing. Our study suggests that by antagonizing miR-214, HNF1A-AS1 activates the SEMA4D/PLEXIN-B1/TIAM/RAC pathway, facilitating EOC growth and potentially promoting M2 macrophage polarization in the tumor microenvironment. HNF1A-AS1 represents a compelling therapeutic target for treating EOC.