Department of Urology, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, 200072, China.
Department of pathology, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, 200072, China.
BMC Cancer. 2018 Nov 20;18(1):1141. doi: 10.1186/s12885-018-5033-y.
This study aimed to explore hyper-O-linked N-acetylglucosaminylation (O-GlcNAcylation) with an elevation of the expression of O-linked-β-N-acetylglucosamine transferase (OGT) in human bladder cancer.
Immunohistochemical staining for OGT and O-GlcNAcylation was performed in 20 paired human bladder cancer and adjacent normal tissues, as well as in human bladder cancer tissue microarrays (N = 169). The expression level of OGT and O-GlcNAcylation in cell lines were detected using the Western blot analysis. The effects of O-GlcNAcylation on the cell proliferation of bladder cancer were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clone formation assays. Cell apoptosis and cell cycle analysis were detected using flow cytometry. The autophagy of bladder cancer cells was investigated using the Western blot analysis, and GFP-LC3 plasmid was used to detect the autophagic flux. MTT assay was performed to detect the sensitivity of bladder cancer cells to cisplatin after OGT knockdown.
The expression of OGT and the O-GlcNAcylation were upregulated in bladder cancer tissues and cell lines. O-GlcNAcylation and OGT were observed in nucleus and cytoplasm and found to be higher in muscle-invasive bladder cancer (MIBC) than in non-muscle-invasive bladder cancer (NMIBC). Reducing hyper-O-GlcNAcylation by OGT knockdown inhibited the proliferation of bladder cancer cells in vitro and xenograft tumor growth in vivo, triggered apoptosis, as well as led to cell cycle arrest. It also increased autophagy in bladder cancer cells. This study demonstrated increased autophagy pro-survival, but not pro-death. Reducing hyper-O-GlcNAcylation by OGT knockdown facilitated the chemosensitivity of bladder cancer cells to cis-platinum.
The data indicated that hyper-O-GlcNAcylation enhanced oncogenic phenotypes and was involved in DNA damage response in bladder cancer.
本研究旨在探讨人膀胱癌中高表达 O-连接-β-N-乙酰氨基葡萄糖转移酶（OGT）导致的高-O-连接-N-乙酰氨基葡萄糖化（O-GlcNAcylation）。
对 20 对人膀胱癌及相邻正常组织和人膀胱癌组织微阵列（N=169）进行 OGT 和 O-GlcNAcylation 的免疫组织化学染色。采用 Western blot 分析检测细胞系中 OGT 和 O-GlcNAcylation 的表达水平。采用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）和克隆形成实验检测 O-GlcNAcylation 对膀胱癌细胞增殖的影响。采用流式细胞术检测细胞凋亡和细胞周期。采用 Western blot 分析检测膀胱癌细胞自噬，并用 GFP-LC3 质粒检测自噬流。采用 MTT 检测 OGT 敲低后膀胱癌细胞对顺铂的敏感性。
OGT 和 O-GlcNAcylation 的表达在膀胱癌组织和细胞系中上调。OGT 和 O-GlcNAcylation 在膀胱癌组织中观察到核内和细胞质内表达，且在肌层浸润性膀胱癌（MIBC）中高于非肌层浸润性膀胱癌（NMIBC）。OGT 敲低可降低高 O-GlcNAcylation，从而抑制膀胱癌细胞的体外增殖和体内异种移植肿瘤生长，引发细胞凋亡，并导致细胞周期停滞。它还增加了膀胱癌细胞中的自噬。本研究表明，增加自噬可促进膀胱癌细胞的存活，但不会促进其死亡。OGT 敲低降低高 O-GlcNAcylation 可提高膀胱癌细胞对顺铂的化疗敏感性。
数据表明，高 O-GlcNAcylation 增强了膀胱癌的致癌表型，并参与了膀胱癌中的 DNA 损伤反应。
