title: In-depth research of multidrug resistance related cell surface glycoproteome in gastric cancer.
abstract: Human gastric cancer is a big public health problem. Multidrug resistance is a main obstacle to successful chemotherapeutic treatment in gastric cancers and the underlying mechanism is not clear. Glycosylation, one of the most important post translational modifications of proteins, plays a vital role in diverse aspects of tumor progression. In the present study, we applied two multidrug resistance cell lines and their parental drug sensitive gastric cancer cell line to a modified cell surface capturing strategy with triplex labeling to characterize MDR related cell surface glycoproteome. Finally, 56 cell membrane glycoproteins were successfully identified via combination of identification by glycopeptides and quantitation by non-glycopeptides, and 11 of them were found to be differentially expressed with the same trend in both drug resistant cell lines compared with that in sensitive cell line. The further analysis by western blot and in vitro drug sensitivity assay demonstrated that our approach is reliable and accurate and suggested that these glycoproteins may represent as biomarkers for multidrug resistance in gastric cancer.
  
  
  CONCLUSIONS
  In this study, we performed a cell surface glycoproteomics research of multidrug resistance in gastric cancer using a modified CSC approach. Totally we identified and quantified 11 membrane N-glycoproteins which were significantly changed in MDR gastric cancer cells. These glycoproteins are quite possible to be biomarkers for predicting MDR or key regulators for targeted therapy, and are also helpful for better interpreting the sophisticated mechanisms of MDR in gastric cancer. In addition to that, this approach used in this study can be well applied to screen aberrantly glycosylated biomarkers associated with other malignant phenotypes of various kinds of cancers.
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, the Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi Province, 710032, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Sun
authors.forename: Jianyong
authors.initials: J
authors.lastname: Zheng
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Lu
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Bian
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Yongzhan
authors.initials: Y
authors.lastname: Nie
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
authors.forename: Daiming
authors.initials: D
authors.lastname: Fan
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D045744:Cell Line, Tumor; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D006023:Glycoproteins; D009363:Neoplasm Proteins; D020543:Proteome