Shu Ming, Guo Kunpeng, Huang Yikai, Wang Weishan
Department of Clinical Laboratory, Shanghai Electric Power Hospital, 937 Yan'an West Road, Changning District, Shanghai, 200000, China.
Department of General Surgery, Shanghai Electric Power Hospital, Changning District, Shanghai, 200000, China.
J Cancer Res Clin Oncol. 2025 Mar 20;151(3):117. doi: 10.1007/s00432-025-06163-4.
NSUN5, also known as NOP2/Sun domain 5, is a pivotal RNA methyltransferase that catalyzes the formation of 5-methylcytosine (m5C). Cuproptosis, induced by elevated copper concentrations, is under investigation as a potential therapeutic strategy for cancer treatment. Despite this, the specific roles and the molecular mechanisms underlying Cuproptosis and NSUN5-mediated m5C modification in cholangiocarcinoma (CCA) remain to be fully elucidated.
Human tissue samples were collected to assess the expression levels of NSUN5 in CCA. In vitro functional assays were conducted to evaluate the biological function of NSUN5. The functional mechanism of NSUN5 on glutaminase (GLS) was investigated using RNA pull-down, RNA immunoprecipitation, molecular docking, and RNA stability assays.
This study identified an upregulation of NSUN5 in CCA tissues. The knockdown of NSUN5 diminished the proliferation, migration, and invasion capabilities of CCA cells in vitro. In contrast, the overexpression of NSUN5 enhanced the growth and metastasis of CCA cells. Additionally, an increased copper content was detected in CCA tissues, which correlated with aggressive clinical features. CCA cells exhibited resistance to cuproptosis by upregulating GLS expression. Functionally, NSUN5 was found to positively modulate GLS expression. The NSUN5-mediated m5C modification at site 137 C on the GLS mRNA sequence stabilizes the GLS mRNA, leading to an accumulation of GLS within cells.
Our findings highlight the critical role of NSUN5 in CCA progression through m5C-dependent stabilization of the GLS transcript, suggesting a potential targeted therapeutic strategy for CCA.
NSUN5，也称为NOP2/Sun结构域5，是一种关键的RNA甲基转移酶，可催化5-甲基胞嘧啶（m5C）的形成。由铜浓度升高诱导的铜死亡作为一种潜在的癌症治疗策略正在研究中。尽管如此，铜死亡和NSUN5介导的m5C修饰在胆管癌（CCA）中的具体作用和分子机制仍有待充分阐明。
收集人体组织样本以评估NSUN5在CCA中的表达水平。进行体外功能试验以评估NSUN5的生物学功能。使用RNA下拉、RNA免疫沉淀、分子对接和RNA稳定性试验研究NSUN5对谷氨酰胺酶（GLS）的功能机制。
本研究发现CCA组织中NSUN5上调。敲低NSUN5可降低体外CCA细胞的增殖、迁移和侵袭能力。相反，NSUN5的过表达增强了CCA细胞的生长和转移。此外，在CCA组织中检测到铜含量增加，这与侵袭性临床特征相关。CCA细胞通过上调GLS表达表现出对铜死亡的抗性。在功能上，发现NSUN5正向调节GLS表达。NSUN5介导的GLS mRNA序列第137位C处的m5C修饰稳定了GLS mRNA，导致细胞内GLS积累。
我们的研究结果突出了NSUN5在CCA进展中通过GLS转录本的m5C依赖性稳定发挥的关键作用，提示了一种潜在的CCA靶向治疗策略。
