Silencing of ITGB6 inhibits the progression of cervical carcinoma via regulating JAK/STAT3 signaling pathway

BACKGROUND: Integrin β6 (ITGB6), a key submonomer of integrin αvβ6, plays an important role in epithelial-to-mesenchymal transition (EMT), wound healing, epithelial-derived tumor growth, fibrosis, and epithelial repair. However, the role of ITGB6 in cervical carcinoma (CC) remains elusive. METHODS: The expression levels of ITGB6 in CC tissues and cell lines were determined using quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability, proliferation, apoptosis, migration, and invasion were evaluated by Cell Counting Kit-8 (CCK-8), colony-forming, flow cytometry, and Transwell assay, respectively. The expression of related proteins, including EMT markers and the Janus kinase/signal transducer and activator of transcription (JAK/STAT3) signaling markers, were detected using western blotting. RESULTS: The ITGB6 expression in CC tissues and cells (C-33A, Hela, SiHa, and Caski) was remarkably higher than that in paracarcinoma tissues and ECT1/E6E7 cells. The data from The Cancer Genome Atlas (TCGA) data set suggested that patients with CC with high ITGB6 expression showed poorer overall survival (OS). Compared with the empty transfection group (si-NC), si-ITGB6 restrained the proliferation, migration, and invasion of SiHa and Hela cells, while promoting cell apoptosis. si-ITGB6 suppression decreased the expression of Snail, vimentin, and N-cadherin, while increasing E-cadherin expression. Further research showed that si-ITGB6 reduced p-JAK1/JAK1, p-JAK2/JAK2, and p-STAT3/STAT3 expression in the JAK/STAT3 signaling pathway. Interestingly, proliferation, migration, invasion, and the expressions of the molecular markers of the JAK/STAT3 signaling pathway and EMT pathway induced by ITGB6 were altered by RO8191 (JAK/STAT3 pathway activator). Furthermore, the protein expression levels of Snail, vimentin, N-cadherin, p-STAT3/STAT3, p-JAK1/JAK1, and p-JAK2/JAK2 in tumor tissues were higher than those in adjacent normal tissue, while the expression level of E-cadherin was downregulated in tumor tissues. CONCLUSIONS: Silencing of ITGB6 restrains cell proliferation, migration and invasion, and promotes apoptosis in CC by inhibiting JAK/STAT signaling pathways. Thus, ITGB6 may perhaps be a new and useful candidate target for treating CC.