ABSTRACT
Our previous studies revealed a novel link between gemcitabine (GEM) chemotherapy and elevated glutamine-fructose-6-phosphate transaminase 2 (GFPT2) expression in pancreatic cancer (PaCa) cells. GFPT2 is a rate-limiting enzyme in the hexosamine biosynthesis pathway (HBP). HBP can enhance metastatic potential by regulating epithelial-mesenchymal transition (EMT). The aim of this study was to further evaluate the effect of chemotherapy-induced GFPT2 expression on metastatic potential. GFPT2 expression was evaluated in a mouse xenograft model following GEM exposure and in clinical specimens of patients after chemotherapy using immunohistochemical analysis. The roles of GFPT2 in HBP activation, downstream pathways, and cellular functions in PaCa cells with regulated GFPT2 expression were investigated. GEM exposure increased GFPT2 expression in tumors resected from a mouse xenograft model and in patients treated with neoadjuvant chemotherapy (NAC). GFPT2 expression was correlated with post-operative liver metastasis after NAC. Its expression activated the HBP, promoting migration and invasion. Treatment with HBP inhibitors reversed these effects. Additionally, GFPT2 upregulated ZEB1 and vimentin expression and downregulated E-cadherin expression. GEM induction upregulated GFPT2 expression. Elevated GFPT2 levels promoted invasion by activating the HBP, suggesting the potential role of this mechanism in promoting chemotherapy-induced metastasis.
