T-Synthase Deficiency Enhances Oncogenic Features in Human Colorectal Cancer Cells via Activation of Epithelial-Mesenchymal Transition
BIOMED RESEARCH INTERNATIONAL
Authors: Dong, Xichen; Jiang, Yuliang; Liu, Jian; Liu, Zhe; Gao, Tianbo; An, Guangyu; Wen, Tao
Abstract
Background. Immature truncated O-glycans such as Tn antigen are frequently detected in human colorectal cancer (CRC); however, the precise pathological consequences of Tn antigen expression on CRC are unknown. T-synthase is the key enzyme required for biosynthesis of mature O-glycans. Here we investigated the functional roles of Tn antigen expression mediated by T-synthase deficiency in CRC cells. Methods. To knock out T-synthase, we used CRISPR-Cas9 technology to target C1GALT1, the gene encoding T-synthase, in a CRC cell line (HCT116). Deletion of T-synthase was confirmed by western blotting, and expression of Tn antigen was determined by flow cytometry in HCT116 cells. We then assessed the biological effects of T-synthase deficiency on oncogenic behaviors in HCT116 cells. Furthermore, we analyzed the mechanistic role of T-synthase deficiency in cancer cells by determining the epithelial-mesenchymal transition (EMT) pathway. Results. We showed that forced knockout of T-synthase in HCT116 cells significantly induced Tn antigen expression, which represented the occurrence of aberrant O-glycosylation. Loss of Tsynthase significantly enhanced cell proliferation and adhesion, as well as migration and invasiveness in culture. More importantly, we demonstrated that T-synthase deficiency directly induced classical EMT characteristics in cancer cells. E-cadherin, a typical epithelial cell marker, was markedly decreased in T-synthase knockout HCT 116 cells, accompanied by an enhanced expression of mesenchymal markers including snail and fibronectin (FN). Conclusions. These findings indicate that T-synthase deficiency in CRC cells not only is responsible for aberrant O-glycosylation, but also triggers themolecular process of EMT pathway, whichmay translate to increased invasiveness and metastasis in cancers.
C1GALT1 activates multiple RTKs and promotes malignant behaviors in pancreatic adenocarcinoma cells
CANCER RESEARCH
Authors: Kuo, Ting-Chun; Juan, Hsueh-Fen; Tien, Yu-Wen; Huang, Min-Chuan
Abstract