GLIS3, a novel prognostic indicator of gastric adenocarcinoma, contributes to the malignant biological behaviors of tumor cells via modulating TGF-β1/TGFβR1/Smad1/5 signaling pathway

GLIS3 is highly expressed in multiple cancers, but it has not been studied in gastric adenocarcinoma (GAC). Based on bioinformatics analysis, the prognostic significance of GLIS3 in GAC was analyzed. GAC cells were transfected with small interfering (si)-GLIS3 and GLIS3 overexpression plasmid as well as treated with SB505124 [an inhibitor for transforming growth factor beta receptor 1 (TGFβR1)] and dorsomorphin [an inhibitor for bone morphogenetic protein receptor 1 (BMPR1)]. The GLIS3 expression was detected using qRT-PCR. The impacts of GLIS3 on the proliferation, invasion and migration of GAC cells were measured using cell function assays. The activation of phosphor (p)-Smad1/5 was tested by immunofluorescence. Western blot was utilized to measure the level of transforming growth factor (TGF)-β1/Smad1/5 signaling pathway-related proteins (TGF-β1, p-Smad1, Smad1, p-Smad5, Smad5). GLIS3 was expressed at high levels in GAC tissues and cell lines and its high expression could indicate the poor prognosis of GAC patients. GLIS3 inhibition declined the proliferative, invasive and migratory capabilities as well as TGF-β1 expression and phosphorylation of Smad1/5 in GAC cells. Overexpressed GLIS3 promoted proliferation, migration, invasion, TGF-β1 expression and Smad1/5 phosphorylation in GAC cells, with SB505124 reversing the effects of overexpressed GLIS3 on proliferation, migration, invasion and Smad1/5 phosphorylation whereas dorsomorphin exhibiting no influence on GLIS3-induced effects. GLIS3 facilitated the malignant phenotype of GAC cells via regulating TGF-β1/TGFβR1/Smad1/5 pathway, which may be a novel prognostic indicator of GAC and provided a target for GAC treatment.