LncRNA HOTAIR Promotes Chemoresistance by Facilitating Epithelial to Mesenchymal Transition through miR-29b/PTEN/PI3K Signaling in Cervical Cancer

Long non-coding RNA HOTAIR has been revealed to participate in the tumorigenesis of various cancers. However, the mechanism of HOTAIR involvement in cervical cancer has not been identified. Hence, this study aimed to explore the oncogenic and chemoresistant roles of HOTAIR in cervical cancer, and its underlying mechanism. RT-PCR, Western blot, and Luciferase assay were employed to determine the relationship of HOTAIR with miR-29b and PTEN and to study the role of HOTAIR in cervical cancer. CCK8 assay, cell migration, and invasion assay were used to reveal the role of HOTAIR in cervical cancer cell proliferation and metastasis. The inhibitory dose of chemotherapeutics was determined by CCK8 assay using probit analysis. HOTAIR was found to bind with miR-29b, and a negative correlation existed between HOTAIR and miR-29b expression in cervical cancer cells. In addition, HOTAIR promoted the migration and proliferation of cervical cancer cell lines HeLa and Siha, showing effects opposite to miR-29b. Further, HOTAIR facilitated the resistance of both HeLa and Siha cells against cisplatin, paclitaxel and docetaxel, whereas miR-29 suppressed the resistance of both cervical cancer cells against the 3chemotherapeutics. In addition, HOTAIR enhanced epithelial-to-mesenchymal transition (EMT), while miR-29b exerted an inhibitory effect on EMT. In cervical cancer cells, miR-29b did not affect promoter methylation of PTEN but regulated PTEN expression by targeting SP1. Transfection of miR-29b mimics led to a significant downregulation of PI3K. HOTAIR promotes chemoresistance by facilitating EMT through the miR-29b/PTEN/PI3K axis in cervical cancer.