Wu Qikai, Lv Jiancheng, Li Xiaojun
Laboratory of Urology and Andrology, Jiangsu Clinical Medicine Research Institution, Nanjing 210029, China.
Department of Urology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China.
Int Immunopharmacol. 2025 Jan 27;146:113802. doi: 10.1016/j.intimp.2024.113802. Epub 2024 Dec 18.
The response rate to immunotherapy in patients with urothelial carcinoma remains limited. Studies have shown that membrane palmitoylated proteins (MPPs) play key roles in tumor progression. However, the mechanisms by which MPP1 regulates immune escape in urothelial carcinoma are not well understood.
The TCGA and BEST databases were used to analyze the associations between the expression of members of the MPP family and the prognosis or immunotherapy sensitivity of urothelial carcinoma patients. MPP1 was identified due to its significant association with survival and immunotherapy sensitivity. MPP1 expression in urothelial carcinoma tissues and cell lines was examined. An MPP1 overexpression vector was used to transfect urothelial carcinoma cells. The functional assays included proliferation, migration, urothelial carcinoma cell-CD8 T-cell coculture, CD8 T-cell chemotaxis, and tumorigenesis in human immune reconstitution NOG mice (HuNOG). Bioinformatics, coimmunoprecipitation (CO-IP), mass spectrometry, quantitative real-time polymerase chain reaction (RT-qPCR), and western blotting were used to validate the activity of the MPP1/USP12/CCL5 cascade.
Analysis of the BEST data revealed that, compared with other MPP family genes, MPP1 was more strongly associated with urothelial carcinoma prognosis and immunotherapy response. Low MPP1 expression was observed in urothelial carcinoma patients and was positively associated with better survival. MPP1 inhibited the proliferation and migration of urothelial carcinoma cells. Bioinformatics, in vitro coculture assays, and in vivo tumorigenesis experiments demonstrated that MPP1 promotes CCL5 production and CD8 T-cell chemotaxis in the urothelial carcinoma tumor microenvironment (TME). Mechanistically, bioinformatics, mass spectrometry, co-IP, RT-qPCR, and western blot analyses indicated that MPP1 increases CCL5 expression by binding to and promoting USP12.
MPP1 significantly inhibits urothelial carcinoma cell proliferation and immune escape via the MPP1/USP12/CCL5 cascade. MPP1 has the potential to serve as a biomarker for guiding immunotherapy in patients with urothelial carcinoma.
尿路上皮癌患者对免疫疗法的反应率仍然有限。研究表明，膜棕榈酰化蛋白（MPP）在肿瘤进展中起关键作用。然而，MPP1调节尿路上皮癌免疫逃逸的机制尚不清楚。
利用TCGA和BEST数据库分析MPP家族成员的表达与尿路上皮癌患者预后或免疫治疗敏感性之间的关联。由于MPP1与生存率和免疫治疗敏感性显著相关，因此对其进行了鉴定。检测了MPP1在尿路上皮癌组织和细胞系中的表达。使用MPP1过表达载体转染尿路上皮癌细胞。功能测定包括增殖、迁移、尿路上皮癌细胞-CD8 T细胞共培养、CD8 T细胞趋化性以及在人免疫重建NOG小鼠（HuNOG）中的肿瘤发生。采用生物信息学、免疫共沉淀（CO-IP）、质谱、定量实时聚合酶链反应（RT-qPCR）和蛋白质印迹法验证MPP1/USP12/CCL5级联反应的活性。
对BEST数据的分析显示，与其他MPP家族基因相比，MPP1与尿路上皮癌预后和免疫治疗反应的相关性更强。在尿路上皮癌患者中观察到MPP1低表达，且与更好的生存率呈正相关。MPP1抑制尿路上皮癌细胞的增殖和迁移。生物信息学、体外共培养试验和体内肿瘤发生实验表明，MPP1促进尿路上皮癌肿瘤微环境（TME）中CCL5的产生和CD8 T细胞趋化性。机制上，生物信息学、质谱、免疫共沉淀、RT-qPCR和蛋白质印迹分析表明，MPP1通过与USP12结合并促进其表达来增加CCL5的表达。
MPP1通过MPP1/USP12/CCL5级联反应显著抑制尿路上皮癌细胞增殖和免疫逃逸。MPP1有潜力作为指导尿路上皮癌患者免疫治疗的生物标志物。
