Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, 510315 Guangzhou, China.
Cancer Institute, Southern Medical University, 510515 Guangzhou, China.
Theranostics. 2021 Jul 13;11(16):8112-8128. doi: 10.7150/thno.54961. eCollection 2021.
The coiled-coil domain containing protein members have been well documented for their roles in many diseases including cancers. However, the function of the coiled-coil domain containing 65 (CCDC65) remains unknown in tumorigenesis including gastric cancer. CCDC65 expression and its correlation with clinical features and prognosis of gastric cancer were analyzed in tissue. The biological role and molecular basis of CCDC65 were performed via in vitro and in vivo assays and a various of experimental methods including co-immunoprecipitation (Co-IP), GST-pull down and ubiquitination analysis et al. Finally, whether metformin affects the pathogenesis of gastric cancer by regulating CCDC65 and its-mediated signaling was investigated. : Here, we found that downregulated CCDC65 level was showed as an unfavourable factor in gastric cancer patients. Subsequently, CCDC65 or its domain (a.a. 130-484) was identified as a significant suppressor in GC growth and metastasis in vitro and in vivo. Molecular basis showed that CCDC65 bound to ENO1, an oncogenic factor has been widely reported to promote the tumor pathogenesis, by its domain (a.a. 130-484) and further promoted ubiquitylation and degradation of ENO1 by recruiting E3 ubiquitin ligase FBXW7. The downregulated ENO1 decreased the binding with AKT1 and further inactivated AKT1, which led to the loss of cell proliferation and EMT signal. Finally, we observed that metformin, a new anti-cancer drug, can significantly induce CCDC65 to suppress ENO1-AKT1 complex-mediated cell proliferation and EMT signals and finally suppresses the malignant phenotypes of gastric cancer cells. These results firstly highlight a critical role of CCDC65 in suppressing ENO1-AKT1 pathway to reduce the progression of gastric cancer and reveals a new molecular mechanism for metformin in suppressing gastric cancer. Our present study provides a new insight into the mechanism and therapy for gastric cancer.
卷曲螺旋结构域包含蛋白成员在许多疾病中，包括癌症中的作用已经得到了很好的记录。然而，卷曲螺旋结构域包含 65 号（CCDC65）在肿瘤发生中的功能在胃癌中仍然未知。在组织中分析了 CCDC65 的表达及其与胃癌临床特征和预后的相关性。通过体外和体内实验以及各种实验方法，包括共免疫沉淀（Co-IP）、GST 下拉和泛素化分析等，研究了 CCDC65 的生物学作用和分子基础。最后，研究了二甲双胍是否通过调节 CCDC65 及其介导的信号通路来影响胃癌的发病机制。在这里，我们发现下调的 CCDC65 水平在胃癌患者中表现为不利因素。随后，CCDC65 或其结构域（a.a. 130-484）被鉴定为体外和体内 GC 生长和转移的重要抑制因子。分子基础表明，CCDC65 通过其结构域（a.a. 130-484）与ENO1 结合，ENO1 是一种广泛报道的促进肿瘤发病机制的致癌因子，并进一步通过招募 E3 泛素连接酶 FBXW7 促进 ENO1 的泛素化和降解。下调的 ENO1 减少了与 AKT1 的结合，并进一步使 AKT1 失活，导致细胞增殖和 EMT 信号丧失。最后，我们观察到二甲双胍，一种新的抗癌药物，可显著诱导 CCDC65 抑制 ENO1-AKT1 复合物介导的细胞增殖和 EMT 信号，最终抑制胃癌细胞的恶性表型。这些结果首次强调了 CCDC65 在抑制 ENO1-AKT1 通路以减少胃癌进展中的关键作用，并揭示了二甲双胍抑制胃癌的新分子机制。我们的研究为胃癌的机制和治疗提供了新的见解。
