A study on the correlation of GDF15 with cancer cell invasion and poor prognosis in gallbladder cancer.

167 Background: Growth differentiation factor 15 (GDF15) is a member of the TGF-β superfamily and has been found to be expressed in various human cancers. This study investigated the role of GDF15 in gallbladder cancer and its underlying molecular mechanisms. Methods: We examined immunohistochemical staining to evaluate the expression of GDF15 in 57 cases of gallbladder cancer using a tissue microarray, and clinic-pathological parameters were analyzed. In addition, we established a stable cell line overexpressing GDF15 using NOZ and OCUG-1 gallbladder cancer cell lines. The successful overexpression of GDF15 was confirmed using RT-PCR and western blot analysis. Migration and invasion assays were performed using transwell plates coated with collagen or matrigel, and cell motility was analyzed using a wound healing assay. We also performed western blot analysis to detect the expression levels of various proteins associated with cell proliferation, migration, and invasion. Results: High GDF15 expression was significantly associated with pathologic T stage ( P = 0.063), differentiation ( P = 0.062), perineal invasion ( P = 0.059) and lymphatic invasion ( P = 0.008). High GDF15 expression has also been associated with poor prognosis. Overexpression of GDF15 significantly enhanced wound healing, cell migration, invasion, and motility in comparison to controls and regulated the expression of related proteins. Our results indicate that GDF15 enhances the migratory, invasive, and motility abilities of NOZ and OCUG-1 cells in vitro and is involved in poor prognosis and overall survival of gallbladder cancer patients. Conclusions: This study implies that GDF15 could serve as a potential therapeutic target in gallbladder cancer.