Sun Huating, Zhang Yinghui, Wang Fang, Wang Zizhao, Zhang Yuhong, Chen Youguo, Wang Li, Zhou Jinhua
Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
Department of Obstetrics and Gynecology, the Affiliated Suzhou Hospital of Nanjing Medical University, Gusu School, Suzhou Municipal Hospital, Nanjing Medical University, No. 26, Daoqian Street, Suzhou, 215002, Jiangsu, China.
J Transl Med. 2025 Apr 8;23(1):406. doi: 10.1186/s12967-025-06409-2.
Cervical cancer (CC) is a prevalent gynecological malignancy, with lymph node metastasis (LNM) serving as a critical factor influencing patient prognosis. SORBS3, an adaptor protein with two known isoforms (α and β), has been implicated in tumor suppression, but the specific roles of its isoforms in CC metastasis remains unexplored. This study aimed to identify the functional isoform of SORBS3 driving LNM suppression and elucidate its mechanisms.
Proteomic analysis of clinical CC tissues and metastatic lymph nodes revealed progressive downregulation of SORBS3. The mRNA and protein levels of SORBS3-α and SORBS3-β were subsequently examined in normal cervical epithelial and CC cell lines. Functional studies, including siRNA-mediated knockdown of SORBS3-α, lentiviral-mediated overexpression and knockdown of SORBS3-β, Transwell migration, lymphangiogenesis assays, and in vivo footpad xenograft models, were conducted to evaluate the role of SORBS3 isoforms in LNM. SORBS3 DNA methylation mechanisms were analyzed by MSP and Targeted Bisulfite sequencing. Mechanistic insights were derived from Co-IP, ubiquitination assays, RNA-seq, and LC-MS/MS.
Knockdown of SORBS3-α had no effect on CC cell migration, invasion, or lymphangiogenesis. In contrast, SORBS3-β overexpression markedly suppressed CC cell invasion, lymphangiogenesis, and adhesion to lymphatic endothelial cells, whereas its knockdown significantly promoted these phenotypes. Promoter hypermethylation driven by DNMT-1 inhibited SORBS3 expression in CC. SORBS3- β directly binds to β-catenin and recruits UBA1 to enhance its ubiquitination and degradation, thereby inhibiting Wnt/β-catenin signaling. This inhibition reduced accumulation of β-catenin and downregulated the pro-lymphangiogenic gene VEGFC, ultimately suppressing lymphangiogenesis and LNM. In vivo, SORBS3-β overexpression attenuated lymphatic metastasis in nude mice, whereas its knockdown promoted metastasis.
SORBS3-β is the major isoform of SORBS3 that inhibits lymphatic metastasis of cervical cancer by degrading β-catenin through UBA1-mediated ubiquitination, blocking Wnt/β-catenin signaling and downstream lymphangiogenesis pathways, thereby inhibiting lymphatic metastasis. Our findings elucidate key molecular mechanisms underlying cervical cancer lymph node metastasis, offering potential therapeutic targets.metastasis.
宫颈癌（CC）是一种常见的妇科恶性肿瘤，淋巴结转移（LNM）是影响患者预后的关键因素。SORBS3是一种有两种已知异构体（α和β）的衔接蛋白，与肿瘤抑制有关，但其异构体在CC转移中的具体作用仍未被探索。本研究旨在确定驱动LNM抑制的SORBS3功能异构体，并阐明其机制。
对临床CC组织和转移淋巴结进行蛋白质组分析，发现SORBS3呈进行性下调。随后检测了正常宫颈上皮和CC细胞系中SORBS3-α和SORBS3-β的mRNA和蛋白水平。进行了功能研究，包括siRNA介导的SORBS3-α敲低、慢病毒介导的SORBS3-β过表达和敲低、Transwell迁移、淋巴管生成测定以及体内足垫异种移植模型，以评估SORBS3异构体在LNM中的作用。通过甲基化特异性PCR（MSP）和靶向亚硫酸氢盐测序分析SORBS3的DNA甲基化机制。通过免疫共沉淀（Co-IP）、泛素化测定、RNA测序（RNA-seq）和液相色谱-质谱联用（LC-MS/MS）获得机制方面的见解。
敲低SORBS3-α对CC细胞迁移、侵袭或淋巴管生成没有影响。相反，SORBS3-β过表达显著抑制CC细胞侵袭、淋巴管生成以及与淋巴管内皮细胞的粘附，而敲低则显著促进这些表型。由DNA甲基转移酶-1（DNMT-1）驱动的启动子高甲基化抑制了CC中SORBS3的表达。SORBS3-β直接与β-连环蛋白结合，并募集泛素激活酶1（UBA1）以增强其泛素化和降解，从而抑制Wnt/β-连环蛋白信号通路。这种抑制减少了β-连环蛋白的积累，并下调了促淋巴管生成基因VEGFC，最终抑制淋巴管生成和LNM。在体内，SORBS3-β过表达减弱了裸鼠的淋巴转移，而敲低则促进了转移。
SORBS3-β是SORBS3的主要异构体，通过UBA1介导的泛素化降解β-连环蛋白，阻断Wnt/β-连环蛋白信号通路和下游淋巴管生成途径，从而抑制宫颈癌的淋巴转移。我们的研究结果阐明了宫颈癌淋巴结转移的关键分子机制，提供了潜在的治疗靶点。
