Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, 1# Jianshe East Road, Zhengzhou, Henan, China.
Apoptosis. 2023 Oct;28(9-10):1315-1331. doi: 10.1007/s10495-023-01861-1. Epub 2023 Jun 19.
Thyroid cancer (TC) is one of the most common endocrine system cancers, and its incidence is elevating. There is an urgent need to develop a deeper understanding of TC pathogenesis and explore new therapeutic target for its treatment. This study aimed to investigate the effects of pleckstrin homology and RhoGEF domain containing G4 (PLEKHG4) on the progression of TC. Herein, 29 pairs of TC and adjacent tissues were used to assess the expression of PLEKHG4. A xenograft model of mouse was established by subcutaneously injected with TC cells. Lung metastasis model was established through left ventricular injection. The results revealed that PLEKHG4 was up-regulated in human TC tissues. PLEKHG4 level was correlated with clinicopathological parameters of TC patients. In vitro assays revealed that PLEKHG4 promoted TC cell proliferation, migration, invasion, and epithelial-mesenchymal transformation. Knockdown of PLEKHG4 led to the opposite effects, and the loss of PLEKHG4 enhanced the apoptosis ability and inhibited the stemness properties of TC cells. These findings were further confirmed by the in vivo growth and lung metastasis of TC tumor. Mechanistically, PLEKHG4 promoted the activation of RhoGTPases RhoA, Cdc42, and Rac1. The inhibitors of these RhoGTPases reversed the PLEKHG4-induced malignant phenotypes. Additionally, ubiquitin-conjugating enzyme E2O (UBE2O), a large E2 ubiquitin-conjugating enzyme acted as an ubiquitin enzyme of PLEKHG4, facilitated its ubiquitination and degradation. In conclusion, PLEKHG4, regulated by UBE2O, promoted the thyroid cancer progression via activating the RhoGTPases pathway. UBE2O/PLEKHG4/RhoGTPases axis is expected to be a novel a therapeutic target for TC treatment.
甲状腺癌 (TC) 是最常见的内分泌系统癌症之一,其发病率正在上升。因此,迫切需要深入了解 TC 的发病机制,并探索新的治疗靶点。本研究旨在探讨 pleckstrin homology and RhoGEF domain containing G4 (PLEKHG4) 对 TC 进展的影响。本研究使用 29 对 TC 组织和相邻组织来评估 PLEKHG4 的表达。通过皮下注射 TC 细胞建立了小鼠移植瘤模型。通过左心室注射建立了肺转移模型。结果表明,PLEKHG4 在人 TC 组织中上调。PLEKHG4 水平与 TC 患者的临床病理参数相关。体外实验表明,PLEKHG4 促进 TC 细胞的增殖、迁移、侵袭和上皮间质转化。PLEKHG4 的敲低导致相反的效果,并且 PLEKHG4 的缺失增强了 TC 细胞的凋亡能力并抑制了其干性。这些发现通过 TC 肿瘤的体内生长和肺转移得到进一步证实。机制上,PLEKHG4 促进了 RhoGTPases RhoA、Cdc42 和 Rac1 的激活。这些 RhoGTPases 的抑制剂逆转了 PLEKHG4 诱导的恶性表型。此外,泛素连接酶 E2O (UBE2O),一种作为 PLEKHG4 的泛素酶的大型 E2 泛素连接酶,促进了其泛素化和降解。总之,UBE2O 调节的 PLEKHG4 通过激活 RhoGTPases 途径促进甲状腺癌的进展。UBE2O/PLEKHG4/RhoGTPases 轴有望成为 TC 治疗的新治疗靶点。