Tang Chao, Li Lin, Zhu Chongying, Xu Qiang, An Zihao, Xu Shouying, Lin Chao
National Clinical Research Center for Child Health of Children's Hospital, Zhejiang University School of Medicine, No. 3333, Binsheng Rd, Hangzhou, 310052, People's Republic of China.
Department of Urology, Third Affiliated Hospital, Naval Medical University, Shanghai, 201805, China.
J Exp Clin Cancer Res. 2025 Jan 24;44(1):22. doi: 10.1186/s13046-025-03275-0.
Ovarian cancer (OC) progression is one of the commonest cause of female cancer death. While treatments in clinic includes primary surgery and targeted chemotherapy, curative and survival trends in OC have not significantly improved. Thus, further investigation of the mechanisms regarding OC carcinogenesis and discovery of novel targets is of great importance.
Human ovarian tissue specimens, RNA sequencing, GEPIA database and bioinformatics analyses were used to analyze the gene correlation, and to identify and validate potential downstream candidates. The biological effects of GPR137-RAB8A-Hedgehog(HH) were investigated using in vitro and in vivo models and methods including qRT-PCR, RNA stability assay, RNA immunoprecipitation assay, GLI-luciferase reporter assay, nucleo-cytoplasmic separation assay, membrane-cytoplasmic separation assay, western blot, co-immunoprecipitation, immunofluorescence staining, cell counting kit-8 assay, wound healing assay, matrigel invasion assay, colony formation assay, xenografts assay, in situ transplantation tumor model of ovarian cancer in nude mice, and immunohistochemistry staining.
GPR137 expression was significantly higher in collected clinical OC tissues, compared with the adjacent normal tissues. Consistently, suppression of GPR137 inhibited human SK-OV-3 and A2780 OC cell proliferation, migration, invasion, and colony formation, whereas overexpression of GPR137 in human OC HO8910 cell exerted the opposite effects on cell biological behaviors. Mechanistically, RAB8A was identified as a downstream target of GPR137, and GPR137 promotes RAB8A expression by promoting RAB8A mRNA stability. By RNA-sequencing and experiments in vitro using multiple ovarian cancer cell models as well as in vivo using subcutaneous xenografts assay and in situ transplantation ovarian cancer model in nude mice, we further demonstrated that RAB8A positively mediated OC progression through activating HH signaling pathway by disassociating the protein-protein complex formation of GLI and SuFu (Suppressor of Fused), which reciprocally enhanced GPR137 activity, forming a regulation loop between HH signaling and GPR137.
Collectively, this study depicts the role of GPR137-RAB8A-HH cascade in the development of OC, deepening our understanding of tumor biomechanics regarding OC progression and providing novel targets for OC therapy in future.
卵巢癌（OC）进展是女性癌症死亡的最常见原因之一。虽然临床上的治疗包括初次手术和靶向化疗，但OC的治愈率和生存率并未显著提高。因此，进一步研究OC致癌机制并发现新靶点具有重要意义。
利用人卵巢组织标本、RNA测序、GEPIA数据库和生物信息学分析来分析基因相关性，并鉴定和验证潜在的下游候选基因。使用体外和体内模型及方法，包括qRT-PCR、RNA稳定性测定、RNA免疫沉淀测定、GLI荧光素酶报告基因测定、核质分离测定、膜质分离测定、蛋白质免疫印迹、免疫共沉淀、免疫荧光染色、细胞计数试剂盒-8测定、伤口愈合测定、基质胶侵袭测定、集落形成测定、异种移植测定、裸鼠卵巢癌原位移植肿瘤模型和免疫组织化学染色，研究GPR137-RAB8A-刺猬（HH）信号通路的生物学效应。
与相邻正常组织相比，收集的临床OC组织中GPR137表达显著更高。同样，抑制GPR137可抑制人SK-OV-3和A2780 OC细胞的增殖、迁移、侵袭和集落形成，而在人OC HO8910细胞中过表达GPR137对细胞生物学行为产生相反的影响。机制上，RAB8A被鉴定为GPR137的下游靶点，GPR137通过促进RAB8A mRNA稳定性来促进RAB8A表达。通过RNA测序以及使用多种卵巢癌细胞模型的体外实验，以及使用皮下异种移植测定和裸鼠卵巢癌原位移植模型的体内实验，我们进一步证明RAB8A通过解离GLI和SuFu（融合抑制因子）的蛋白质-蛋白质复合物形成来激活HH信号通路，从而正向介导OC进展，这反过来又增强了GPR137活性，在HH信号通路和GPR137之间形成了一个调节环。
总体而言，本研究描述了GPR137-RAB8A-HH级联在OC发生发展中的作用，加深了我们对OC进展的肿瘤生物力学的理解，并为未来OC治疗提供了新靶点。
