Department of Gynecology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China.
Theranostics. 2023 Jan 5;13(2):833-848. doi: 10.7150/thno.77441. eCollection 2023.
Lymph node (LN) metastasis is common in patients with epithelial ovarian cancer (EOC) and is associated with poor prognosis. Tumor-associated lymphangiogenesis is the first stage of LN metastasis. Research on lymphangiogenesis and lymph node metastases can help develop new anti-LN-targeted therapies. Aberrant N6-methyladenosine (m6A) modifications have been reported to be linked to LN metastasis in several cancers, however, their role in EOC lymphangiogenesis and LN metastasis remains unclear. m6A levels in EOC tissues with or without LN metastases were evaluated by dot blot analysis. Real-time polymerase chain reaction (PCR) and immunofluorescence were used to examine the expression of m6A-related enzymes. Additionally, and functional studies were performed to discover the importance of the AlkB homolog 5 () gene in EOC lymphatic metastasis. To identify the downstream target genes regulated by ALKBH5, we performed RNA pulldown, RNA-binding protein immunoprecipitation-quantitative PCR, co-immunoprecipitation, m6A-modified RNA immunoprecipitation-quantitative PCR, and luciferase reporter assays. m6A modification was reduced in ovarian cancers with LN metastases. ALKBH5 overexpression increased tumor-associated lymphangiogenesis and LN metastasis both and . ALKBH5 overexpression also reversed the m6A modification in mRNA and suppressed the YTHDF2 protein-mediated m6A-dependent mRNA degradation, which resulted in increased expression of ITGB1 and phosphorylation of the focal adhesion kinase (FAK) and Src proto-oncogene proteins, thereby increasing LN metastasis. Furthermore, hypoxia induced the expression of hypoxia inducible factor 1 subunit alpha, which increased ALKBH5 expression and enhanced LN metastasis in EOC. The ALKBH5/m6A-ITGB1/FAK signalling axis is important in ovarian cancer lymphangiogenesis and LN metastasis. Antibodies that block ITGB1 and FAK kinase-inhibitors are promising anti-metastatic agents.
淋巴结（LN）转移在卵巢上皮癌（EOC）患者中很常见，与预后不良有关。肿瘤相关淋巴管生成是 LN 转移的第一阶段。对淋巴管生成和淋巴结转移的研究有助于开发新的抗 LN 靶向治疗方法。已有研究报道，异常的 N6-甲基腺苷（m6A）修饰与几种癌症的 LN 转移有关，然而，其在 EOC 淋巴管生成和 LN 转移中的作用尚不清楚。通过斑点印迹分析评估有无 LN 转移的 EOC 组织中的 m6A 水平。实时聚合酶链反应（PCR）和免疫荧光用于检测 m6A 相关酶的表达。此外，进行了 和 功能研究，以发现 AlkB 同源物 5（）基因在 EOC 淋巴转移中的重要性。为了确定受 ALKBH5 调控的下游靶基因，我们进行了 RNA 下拉、RNA 结合蛋白免疫沉淀-定量 PCR、共免疫沉淀、m6A 修饰 RNA 免疫沉淀-定量 PCR 和荧光素酶报告基因检测。LN 转移的卵巢癌中 m6A 修饰减少。ALKBH5 过表达增加肿瘤相关淋巴管生成和 LN 转移 both 和. ALKBH5 过表达还逆转了 mRNA 的 m6A 修饰，并抑制了 YTHDF2 蛋白介导的 m6A 依赖性 mRNA 降解，从而增加了 ITGB1 的表达和粘着斑激酶（FAK）和原癌基因 Src 蛋白的磷酸化，从而增加了 LN 转移。此外，缺氧诱导缺氧诱导因子 1 亚单位 alpha 的表达，增加了 ALKBH5 的表达，并增强了 EOC 中的 LN 转移。ALKBH5/m6A-ITGB1/FAK 信号轴在卵巢癌淋巴管生成和 LN 转移中起重要作用。阻断 ITGB1 和 FAK 激酶的抗体是很有前途的抗转移药物。
