Department of Ophthalmology, Yunnan No. 2 Provincial People's Hospital, Kunming, Yunnan, China (mainland).
Department of Neurosurgery, HuZhou Central Hospital, Huzhou, Zhejiang, China (mainland).
Med Sci Monit. 2019 Nov 8;25:8422-8429. doi: 10.12659/MSM.916024.
BACKGROUND Herein, we found that tripartite motif-containing 48 (TRIM48) was reduced in human glioblastoma (GBM) cell lines. We investigated whether and how TRIM48 functions in human GBM in vitro. MATERIAL AND METHODS Human GBM cells (U87 MG and U138 MG) were infected with lentivirus to overexpress TRIM48, and 1 human GBM cell line (T98G) was infected with siRNAs to knock down TRIM48 expression. Techniques used included cell proliferation assay, measured by CCK-8 and BrdU-ELISA method, and cell cycle assay, determined using flow cytometry. Curcumin, a specific activator of extracellular signal regulated kinases (ERK1/2), or PD98059, a specific inhibitor of ERK1/2, was used to activate or block the ERK1/2 pathway, respectively. Expression of phosphorylated (p)-ERK1/2, and its downstream targets (Cyclin D1) were measured to assess the mechanism. RESULTS Our data suggest that overexpression of TRIM48 reduces the viability of U87 MG and U138 MG and leads to cell cycle arrest (in G0-G1 phase), which is associated with blockade of the ERK1/2 pathway and reduction of Cyclin D1. In contrast, knockdown of TRIM48 resulted in the opposite effects. Interestingly, the inhibitory effect of TRIM48 overexpression on human GBM cell growth and the inactivation of ERK1/2 were significantly alleviated with additional curcumin treatment, while it the promoted the effect of siTRIM48 on human GBM cell growth, and the activation of ERK1/2 was significantly alleviated with additional PD98059 treatment. CONCLUSIONS TRIM48 suppressed the growth of human GBM cell via the prevention of ERK1/2 activation.
在此，我们发现三结构域蛋白 48（TRIM48）在人胶质母细胞瘤（GBM）细胞系中减少。我们研究了 TRIM48 在体外是否以及如何在人 GBM 中发挥作用。
用人慢病毒感染 U87 MG 和 U138 MG 人 GBM 细胞系以过表达 TRIM48，并用 siRNA 感染 T98G 人 GBM 细胞系以敲低 TRIM48 的表达。使用的技术包括 CCK-8 和 BrdU-ELISA 法测量的细胞增殖测定法，以及通过流式细胞术确定的细胞周期测定法。姜黄素，一种细胞外信号调节激酶（ERK1/2）的特异性激活剂，或 PD98059，一种 ERK1/2 的特异性抑制剂，分别用于激活或阻断 ERK1/2 通路。测量磷酸化（p）-ERK1/2 及其下游靶标（Cyclin D1）的表达以评估机制。
我们的数据表明，TRIM48 的过表达降低了 U87 MG 和 U138 MG 的活力，并导致细胞周期停滞（在 G0-G1 期），这与 ERK1/2 通路的阻断和 Cyclin D1 的减少有关。相反，敲低 TRIM48 则产生相反的效果。有趣的是，TRIM48 过表达对人 GBM 细胞生长的抑制作用和 ERK1/2 的失活作用随着姜黄素的额外处理而明显减轻，而它对人 GBM 细胞生长的促进作用和 ERK1/2 的激活作用随着 PD98059 的额外处理而明显减轻。
TRIM48 通过阻止 ERK1/2 的激活来抑制人 GBM 细胞的生长。
