LncRNA HEIH Enhances Paclitaxel-Tolerance of Endometrial Cancer Cells via Activation of MAPK Signaling Pathway

This study aimed to investigate the function of lncRNA HEIH on promoting endometrial cancer cells' tolerance of paclitaxel (PTX). LncRNA HEIH expression was measured by QRT-PCR in endometrial cancer tissues, human healthy tissues and cell lines. The PTX-resistant endometrial cancer cells (Ishikawa-RE and HHUA-RE) were intermittently exposed to increase concentrations of PTX and were constructed as evidenced by MTT assay. Besides, the specific siRNA of HEIH (siHEIH) and pcDNA3.1-HEIH plasmid transfection were utilized to alter the expression of HEIH in the cells and investigate the effects of HEIH on resistance to PTX in endometrial cancer cells. Moreover, MTT, colony formation and apoptosis analysis were taken advantage to evaluate cell viability and proliferation when treated with PTX. Then, differential genes in PTX-resistant and HEIH-knock-down PTX-resistant endometrial cancer cells were screened out by microarray analysis. Finally, gene-set enrichment analysis was used to predict the promising signaling pathway of HEIH and western blotting analysis were performed to verify the relevant genes expression of MAPK signaling pathway. LncRNA HEIH, the dysregulation of which involved in production of drug-resistance, was overexpressed in PTX-resistant endometrial cancer cells. Up-regulating HEIH would activate MAPK pathway, promote chemo-resistance of endometrial cancer cells and enhance cell proliferation and viability, whereas silencing HEIH depressed the MAPK signaling pathway, contributed to restoring chemo-sensitivity to PTX and repressed cell physiological process. Down-regulating lncRNA HEIH expression reversed the PTX-resistance of endometrial cancer cells through MAPK signaling pathway.