Tobisawa Yuki, Nakane Keita, Koie Takuya, Taniguchi Tomoki, Tomioka Masayuki, Tomioka-Inagawa Risa, Kawase Kota, Kawase Makoto, Iinuma Koji
Department of Urology, Graduate School of Medicine, Gifu University, Gifu 5011194, Japan.
Center for One Medicine Innovative Translational Research (COMIT), Institute for Advanced Study, Gifu University, Gifu 5011194, Japan.
Biomedicines. 2025 Mar 10;13(3):682. doi: 10.3390/biomedicines13030682.
Abnormal glycan formation on the cancer cell surface plays a crucial role in regulating tumor functions in bladder cancer. In this study, we investigated the roles of glucosaminyl (-acetyl) transferase 2 (GCNT2) in bladder cancer progression and immune evasion. GCNT2 synthesizes I-branched polylactosamine chains on cell surface glycoproteins. Understanding its functions will provide insights into tumor-immune interactions, facilitating the development of effective immunotherapeutic strategies. GCNT2 expression levels in bladder cancer cell lines and patient tumor samples were analyzed via quantitative polymerase chain reaction and immunohistochemistry. GCNT2 functions were assessed via overexpression and knockdown experiments. Its effect on natural killer (NK) cell-mediated cytotoxicity was evaluated via in vitro assay. Cytotoxic granule release from NK cells was measured via enzyme-linked immunosorbent assay. GCNT2 expression was inversely correlated with bladder cancer aggressiveness in both cell lines and patient samples. Low GCNT2 levels were associated with advanced tumor stage and grade, suggesting the tumor-suppressive roles of GCNT2. Notably, GCNT2 overexpression enhanced the susceptibility of bladder cancer cells to NK cell-mediated killing, whereas its knockdown promoted immune evasion. GCNT2-overexpressing cells strongly induced the release of cytotoxic granules from NK cells, indicating enhanced immune recognition. Our findings suggest that aggressive bladder tumors evade NK cell immunity by decreasing the GCNT2 levels and that I-antigen glycans synthesized by GCNT2 are crucial for NK cell recognition by tumor cells. Our findings provide insights into the tumor-immune interactions in bladder cancer and GCNT2 and its associated pathways as potential targets for novel immunotherapeutic strategies.
癌细胞表面异常聚糖的形成在调节膀胱癌的肿瘤功能中起着关键作用。在本研究中，我们调查了氨基葡萄糖基（-乙酰）转移酶2（GCNT2）在膀胱癌进展和免疫逃逸中的作用。GCNT2在细胞表面糖蛋白上合成I分支的聚乳糖胺链。了解其功能将有助于深入了解肿瘤-免疫相互作用，促进有效的免疫治疗策略的开发。通过定量聚合酶链反应和免疫组织化学分析了膀胱癌细胞系和患者肿瘤样本中GCNT2的表达水平。通过过表达和敲低实验评估GCNT2的功能。通过体外试验评估其对自然杀伤（NK）细胞介导的细胞毒性的影响。通过酶联免疫吸附测定法测量NK细胞的细胞毒性颗粒释放。在细胞系和患者样本中，GCNT2表达均与膀胱癌侵袭性呈负相关。低GCNT2水平与肿瘤晚期和高分级相关，提示GCNT2具有肿瘤抑制作用。值得注意的是，GCNT2过表达增强了膀胱癌细胞对NK细胞介导杀伤的敏感性，而其敲低则促进了免疫逃逸。过表达GCNT2的细胞强烈诱导NK细胞释放细胞毒性颗粒，表明免疫识别增强。我们的研究结果表明，侵袭性膀胱肿瘤通过降低GCNT2水平逃避NK细胞免疫，并且GCNT2合成的I抗原聚糖对于NK细胞识别肿瘤细胞至关重要。我们的研究结果为膀胱癌中的肿瘤-免疫相互作用以及GCNT2及其相关途径作为新型免疫治疗策略的潜在靶点提供了见解。
