Overexpression of glycosyltransferase 8 domain containing 2 confers ovarian cancer to CDDP resistance by activating FGFR/PI3K signalling axis

It has been reported that chemotherapy resistance mainly contributed to treatment failure and poor survival in patients with ovarian cancer. Therefore, clarifying the molecular mechanism and identifying effective strategies to overcome drug resistance may play an important clinical impact on this malignant tumor. In our study, we found that the expression of Glycosyltransferase 8 domain containing 2 (GLT8D2) was significantly upregulated in ovarian cancer samples with CDDP (Cis-dichlorodiammine-platinum) resistance. Biological experiment demonstrate that GLT8D2 overexpression confers CDDP resistance on ovarian cancer cells; however, inhibition of GLT8D2 sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. By using affinity purification/mass spectrometry (IP/MS) and reciprocal co-immunoprecipitation (co-IP) analyses, we found that GLT8D2 interacts with fibroblast growth factor receptor 1(FGFR1) in ovarian cancer cells. Furthermore, overexpression of GLT8D2 activated FGFR/PI3K signaling axis and upregulated the phosphorylation levels of FRS2a and AKT (AKT serine/threonine kinase). Importantly, pharmacological inhibition of FGFR and PI3K (phosphatidylinositol 3-kinase) signaling pathway significantly counteracted GLT8D2-induced chemoresistance and enhanced platinum’s therapeutic efficacy in ovarian cancer. Therefore, our findings suggest that GLT8D2 is a potential therapeutic target for the treatment of ovarian cancer; targeting GLT8D2/FGFR/PI3K/AKT signaling axis may represent a promising strategy to enhance platinum response in patients with chemoresistant ovarian cancer.