Li Jianchang, Liu Xiuming, Wang Wenqi, Li Chaopeng, Li Xiaofeng
Department of Ophthalmology, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huai' an, Jiangsu, China.
Arch Med Sci. 2019 Jun 14;16(5):1176-1188. doi: 10.5114/aoms.2019.85810. eCollection 2020.
Uveal melanoma is known as a frequent intraocular tumor, with high metastasis and poor prognosis. Mitogen- and stress-activated protein kinase 1 (MSK1) is a serine/threonine kinase that has been reported to be associated with tumor progression in several types of human cancer. However, the role of MSK1 has rarely been studied in uveal melanoma and the underlying mechanism remained unclear.
The expression level of MSK1 in human uveal melanoma tissues and normal uveal tissues was determined by qRT-PCR analysis, western blotting and immunohistochemistry (IHC). Subsequently, MTT assay, colony formation assay and flow cytometry assay were performed to assess the effects of MSK1 on cell proliferation. Wound-healing and transwell chamber assays were adopted to clarify the role of MSK1 in cell metastasis. Finally, the function of MSK1 was confirmed in vivo in a tumor-bearing mouse model.
The expression levels of MSK1 and p-cyclic AMP-responsive element binding protein (CREB) were strongly up-regulated in human uveal melanoma tissues. MSK1 overexpression facilitated cell viability and clone formation, and promoted migration and invasion of uveal melanoma cells. However, mutation of cyclic AMP-responsive element binding protein (CREB) at Ser133 residues reversed the effect of MSK1 on uveal melanoma cell proliferation and metastasis. The experiment suggested that the tumor weight was lower and the tumor mass grew more slowly in the shMSK1 group as compared to the shNC group.
MSK1 promotes proliferation and metastasis of uveal melanoma cells by phosphorylated CREB at Ser133 residues. Therefore, MSK1 could be a promising candidate for uveal melanoma therapy and especially has tremendous potential in the treatment of cancers in which the MSK1-CREB pathway is abnormally active.
葡萄膜黑色素瘤是一种常见的眼内肿瘤，具有高转移性和不良预后。丝裂原和应激激活蛋白激酶1（MSK1）是一种丝氨酸/苏氨酸激酶，据报道在几种人类癌症中与肿瘤进展相关。然而，MSK1在葡萄膜黑色素瘤中的作用鲜有研究，其潜在机制仍不清楚。
通过qRT-PCR分析、蛋白质印迹法和免疫组织化学（IHC）检测人葡萄膜黑色素瘤组织和正常葡萄膜组织中MSK1的表达水平。随后，进行MTT法、集落形成试验和流式细胞术试验以评估MSK1对细胞增殖的影响。采用伤口愈合试验和Transwell小室试验来阐明MSK1在细胞转移中的作用。最后，在荷瘤小鼠模型中体内证实MSK1的功能。
人葡萄膜黑色素瘤组织中MSK1和磷酸化环磷酸腺苷反应元件结合蛋白（CREB）的表达水平显著上调。MSK1过表达促进细胞活力和克隆形成，并促进葡萄膜黑色素瘤细胞的迁移和侵袭。然而，CREB第133位丝氨酸残基的突变逆转了MSK1对葡萄膜黑色素瘤细胞增殖和转移的影响。实验表明，与shNC组相比，shMSK1组的肿瘤重量更低，肿瘤块生长更缓慢。
MSK1通过磷酸化CREB的第133位丝氨酸残基促进葡萄膜黑色素瘤细胞的增殖和转移。因此，MSK1可能是葡萄膜黑色素瘤治疗的一个有前景的候选靶点，尤其在治疗MSK1-CREB通路异常活跃的癌症方面具有巨大潜力。
