TGFBR2 Regulates Hedgehog Pathway and Cervical Cancer Cell Proliferation and Migration by Mediating SMAD4.

Abstract

TGFBR2 serves as an initial regulator of the TGF-β signaling pathway, and loss or reduction of its expression can lead to uncontrolled cell growth. This study was conducted to further explore the mechanism of TGFBR2/SMAD4 on the migration and proliferation of CC cells. Here, TGFBR2 and SMAD4 expressions in CC cells and control cells were measured. The expression patterns of TGFBR2 and SMAD4 in CC cells were verified in the TCGA database. After CC cells were transfected with pcDNA3.1-TGFBR2 or pcDNA3.1-SMAD4, or cotransfected with pcDNA3.1-TGFBR2 and si-SMAD4, Co-IP was utilized for identification of the interaction between TGFBR2 and SMAD4, CCK-8 assay for the assessment of CC cell proliferation, and flow cytometry for the performance of cell cycles. After that, the migration ability of CC cells was examined by cell scratch assay. The expression levels of Hedgehog signaling pathway-related proteins (GLI1 and PTCH) were assayed by Western blot. Lowly expressed TGFBR2 and SMAD4 in CC cells were displayed by the TCGA database. Overexpression of TGFBR2 restrained CC cell migration and proliferation abilities, while the coeffect of TGFBR2 overexpression and SMAD4 knockdown reversed these trends. Besides, highly expressed PTCH and lowly expressed GLI1 were found in CC cells with overexpression of TGFBR2 or SMAD4. The Hedgehog signaling inhibitor (GANT58) can substantially hinder the development of CC cells. Cells in pcDNA3.1-TGFBR2 + si-SMAD4 + GANT58 group had suppressed abilities of cell proliferation and migration than those in pcDNA3.1-TGFBR2 + si-SMAD4 group. Hedgehog pathway agonist (SAG) reversed the inhibitory effect of pcDNA3.1-TGFBR2 or pcDNA3.1-SMAD4 on CC cell biological function. Collectively, TGFBR2 restrains the migration and proliferation abilities of CC cells via mediating SMAD4 to partially block the Hedgehog signaling pathway.