Shen Tianyu, Su Yu, Wang Dekun, Li Gang, Liu Xuan, Sun Chuangxin, Hu Taoyu, Pang Haoxiang, Mi Xue, Zhang Yuying, Yue Shijing, Zhang Zhujun, Tan Xiaoyue
The School of Medicine, Nankai University; 94 Wei Jin Road, Tianjin, China.
Department of Urology, Tianjin Institute of Urology, the 2nd Hospital of Tianjin Medical University, 23 Ping Jiang Road, Tianjin, China.
Cell Death Dis. 2025 Feb 13;16(1):93. doi: 10.1038/s41419-025-07432-3.
The role of hypoxia-inducible factor 2α (HIF2α) in clear cell Renal Cell Carcinoma (ccRCC) is still not fully understood. In this study, we identified that urinary prolegumain levels positively correlated with the malignant characteristics of ccRCC. In cultured 786-O and OSRC-2 cells, HIF2α downregulation reduced prolegumain secretion. RNA sequencing assay revealed that HIF2α induces methylation-controlled J (MCJ), a negative regulator on the mitochondrial respiratory chain. Silencing MCJ reduced prolegumain secretion, and MCJ overexpression restored prolegumain secretion inhibited by HIF2α downregulation. Chromatin immunoprecipitation and luciferase assay confirmed MCJ as a transcription target of HIF2α. Furthermore, we showed the ectopic MCJ overexpression reversed the improved mitochondrial damage resulting from HIF2α downregulation, as evidenced by electron microscope, ATP level, GSSG/GSH ratio, MitoSOX, and DHE staining. Through mass spectrometry analysis, we identified oxidation site His343 on the legumain sequence as contributing to the prolegumain secretion. Therapeutically, silencing MCJ or HIF2α or using ROS scavengers Vitamin C or MitoQ alleviated MMP2 activation as well as cell migration and tube formation. In a mouse orthotopic xenograft model of ccRCC, silencing MCJ or administration of MitoQ significantly protected against mitochondrial damage and subsequently reduced the lung metastasis of tumors. Overall, our study identified MCJ as a target molecule of HIF2α in ccRCC. Silencing MCJ or using ROS scavengers like MitoQ can suppress oxidation site His343 in legumain, preventing prolegumain secretion and subsequently reducing metastasis of ccRCC.
缺氧诱导因子2α（HIF2α）在透明细胞肾细胞癌（ccRCC）中的作用仍未完全明确。在本研究中，我们发现尿中prolegumain水平与ccRCC的恶性特征呈正相关。在培养的786 - O和OSRC - 2细胞中，HIF2α下调减少了prolegumain的分泌。RNA测序分析显示，HIF2α诱导甲基化控制的J（MCJ），这是线粒体呼吸链上的一个负调节因子。沉默MCJ可减少prolegumain的分泌，而MCJ过表达可恢复因HIF2α下调而被抑制的prolegumain分泌。染色质免疫沉淀和荧光素酶测定证实MCJ是HIF2α的转录靶点。此外，我们发现异位MCJ过表达逆转了因HIF2α下调而改善的线粒体损伤，这通过电子显微镜、ATP水平、GSSG/GSH比值、MitoSOX和DHE染色得以证实。通过质谱分析，我们确定legumain序列上的氧化位点His343有助于prolegumain的分泌。在治疗方面，沉默MCJ或HIF2α或使用活性氧清除剂维生素C或MitoQ可减轻MMP2的激活以及细胞迁移和管形成。在ccRCC的小鼠原位异种移植模型中，沉默MCJ或给予MitoQ可显著预防线粒体损伤，进而减少肿瘤的肺转移。总体而言，我们的研究确定MCJ是ccRCC中HIF2α的靶分子。沉默MCJ或使用MitoQ等活性氧清除剂可抑制legumain中的氧化位点His343，阻止prolegumain的分泌，从而减少ccRCC的转移。
