The central role of HOTAIR in the malignancy of CD44+ human hypopharyngeal carcinoma cells.

Human hypopharyngeal carcinoma is one of the most common malignant tumors. CD44 could serve as a molecular marker to screen for cancer stem cells (CSCs) in hypopharyngeal cancer. The aim of this study was to identify the role of HOX transcript antisense RNA (HOTAIR) on cell proliferation and invasion in CD44+ FADU cells (human hypopharyngeal carcinoma cells). We also explored the underlying mechanism contributing to HOTAIR's observed effects. CD44+ FADU cells were sorted and purified by flow cytometry and infected with lentivirus stably expressing HOTAIR shRNA. Cell proliferation and invasion analyses were carried out with cell counting kit-8 (CCK-8) and Transwell assays. The expressions of downstream effectors of HOTAIR, including E-cadherin, β-catenin, and vimentin were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting. Knockdown of HOTAIR markedly inhibited the proliferation and invasion of CD44+ FADU cells in vitro. HOTAIR depletion also increased the expressions of tumor suppressors E-cadherin and β-catenin and decreased the expression of oncogenic vimentin at both mRNA and protein levels. Collectively, our results show that HOTAIR can suppress CD44+ FADU cells proliferation and invasion by regulating the expressions of E-cadherin, β-catenin, and vimentin.