TIPE2 Inhibits Migration and Promotes Apoptosis as a Tumor Suppressor in Hypopharyngeal Carcinoma

Background: Hypopharyngeal squamous cell carcinoma (HSCC) is a common malignant cancer characterized by high metastasis and infiltration. The development of new approaches for the early diagnosis and identification of new therapeutic targets is essential. TIPE2 is well known as a tumor suppressor and related to a favorable prognosis of HSCC. However, its underlying mechanism remains unclear. Methods and Materials: TIPE2 expression was determined by immunohistochemistry and RT-qPCR. A TIPE2 overexpression stable cell line was generated by lentivirus infection. TIPE2 and other related protein levels were detected by western blotting. The cell cycle and apoptosis were performed by flow cytometric analysis. Cell proliferation was measured with a Cell Counting Kit-8 (CCK-8) assay, and the activity of caspase-3 and caspase-7 was assessed by Caspase-Glo® 3/7 Assay. All data were analyzed with SPSS 25 and GraphPad Prism 8.0. Results: TIPE2 expression was significantly down-regulated in HSCC. Low TIPE2 expression may be associated with poor prognosis in HSCC. TIPE2 overexpression markedly inhibited tumor cell migration. Moreover, TIPE2 decreased cell proliferation but promoted apoptosis. TIPE2 suppressed tumor growth by activating Epithelial-Mesenchymal Transition (EMT) and the extrinsic apoptosis pathway. Conclusion: TIPE2 inhibited tumor progression by suppressing cell migration but promoting apoptosis. TIPE2 can be a new therapeutic target in HSCC.