Glia maturation factor-γ (GMFG) promotes ovarian tumorigenesis and chemoresistance via activation of the FAK signaling-associated focal adhesion dynamics 

Glia maturation factor-γ (GMFG) is reported to regulate actin cytoskeleton remodeling through the facilitation of actin debranching and nucleation suppression, which may be associated with cellular malignancy, but the role of GMFG in tumorigenesis remains largely unknown. By overexpressing or silencing of GMFG in ovarian cancer cell lines, we show that GMFG enhances in vitro ovarian cancer cell proliferation, migration, invasion, and paclitaxel resistance and accelerates in vivo tumor growth and intraperitoneal metastasis in xenograft animal models. The mechanistic study demonstrates that GMFG activates the FAK/Talin/Paxillin/Src signaling molecules via binding to p-FAK (Tyr397) and p-Talin (Ser425), whereas cell proliferation, migration and paclitaxel resistance induced by GMFG can be inversely suppressed by the chemical inhibition of p-FAK (Tyr397). Additionally, patients with high expression of GMFG exhibited a poor progression-free survival (PFS) (HR = 1.42, 95%CI: 1.1 − 1.82, P = 0.0065). To conclude, our study suggests that GMFG may activate FAK signaling via binding to p-FAK (tyr397) and p-Talin (ser425) to promote ovarian tumorigenesis and chemoresistance. These findings indicate a functional interaction between GMFG and FAK pathway in ovarian tumorigenesis and chemoresistance. Thus, targeting the oncogenic GMFG-FAK axis may be a promising therapeutic strategy for ovarian cancer.