Upregulation of MTHFD2 is associated with PD-L1 activation in bladder cancer via the PI3K/AKT pathway
Upregulation of MTHFD2 is associated with PD-L1 activation in bladder cancer via the PI3K/AKT pathway
复制标题
MTHFD2的上调通过PI3K/AKT通路与膀胱癌中PD-L1的激活相关
DOI：
10.3892/ijmm.2022.5217
复制
发表时间：
2023-02-01
影响因子：
5.4
通讯作者：
Zhang, Wensheng
中科院分区：
文献类型：
--
作者：
Deng, Xinxi;Liu, Xiaoqiang;Zhang, Wensheng
亚甲基四氢叶酸脱氢酶2（MTHFD 2）与多种人类恶性肿瘤的病因有关，但其在膀胱癌（BC）中的确切作用仍有待探讨。通过逆转录-定量PCR、免疫印迹和免疫组化检测BC组织，结合肿瘤基因组图谱（TCGA）数据库分析，证实MTHFD 2在BC组织中表达上调。BC患者MTHFD 2表达通常与预后不良、肿瘤免疫细胞浸润和程序性死亡配体1（PD-L1）表达相关。随后，使用短发夹RNA，在BC细胞系中敲低MTHFD 2的表达水平，结果显示，如通过细胞计数试剂盒8和集落形成测定所确定的，肿瘤细胞增殖和细胞集落形成能力大大降低，如通过蛋白质印迹所确定的，PD-L1的表达也是如此。这些发现也在异种移植裸鼠模型中得到证实。同时，在RNA测序和TCGA数据集中均显示MTHFD 2的异常表达与PI 3 K/AKT信号通路密切相关。通过Western印迹法检测PI 3 K和AKT的蛋白表达水平，验证了这一观察结果。在用740 Y-P（一种PI 3 K激活剂）刺激后，BC细胞（T24）中PI 3 K和AKT的激活增强，并且细胞活性和PD-L1表达水平恢复。最后，证明了MTHFD 2水平与对传统BC化疗剂和各种PI 3 K/AKT靶向药物的化学敏感性相关，如通过分析癌症药物敏感性基因组学数据库所确定的。总体而言，目前的研究结果显示，MTHFD 2的上调与BC中PD-L1通过PI 3 K/AKT信号通路活化相关，这表明它可能是BC化疗和免疫治疗的有希望的标志物。
Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) has been implicated in the etiology of various human malignant tumors; however, its exact role in bladder cancer (BC) remains to be explored. Through reverse transcription-quantitative PCR, western blotting and immunohistochemistry detection of BC tissue, combined with The Cancer Genome Atlas (TCGA) database analysis, the present study demonstrated that MTHFD2 was upregulated in BC tissues. MTHFD2 expression in patients with BC was frequently associated with worse prognosis, tumor immune cell infiltration and programmed death-ligand 1 (PD-L1) expression. Subsequently, using short hairpin RNA, the expression levels of MTHFD2 were knocked down in BC cell lines, and the results revealed that the tumor cell proliferation and colony formation abilities of cells were greatly reduced, as determined by Cell Counting Kit 8 and colony formation assays, as was the expression of PD-L1, as determined by western blotting. These findings were also confirmed in a xenograft nude mouse model. Simultaneously, it was revealed that abnormal expression of MTHFD2 was closely associated with the PI3K/AKT signaling pathway in both RNA-sequencing and TCGA datasets. This observation was verified in vitro by detecting the protein expression levels of PI3K and AKT by western blotting. The activation of PI3K and AKT was enhanced in BC cells (T24) following stimulation with 740Y-P, a PI3K activator, and cellular activities and PD-L1 expression levels were restored. Finally, it was demonstrated that the MTHFD2 levels were correlated with chemosensitivity to traditional BC chemotherapeutic agents and various PI3K/AKT-targeted drugs, as determined by analyzing the Genomics of Drug Sensitivity in Cancer database. Overall, the present findings revealed that upregulation of MTHFD2 was associated with PD-L1 activation in BC via the PI3K/AKT signaling pathway, suggesting that it could be a promising marker of chemotherapy and immunotherapy for BC.