Zhu Jianjun, Shi Lihong, Du Genlai, Li Li, Liu Ming
Department of Medical Cellular Biology and Genetics, Shanxi Medical University, Taiyuan 030001, People's Republic of China.
Department of Human Anatomy, School of Basic Medicine, Shanxi Medical University, Taiyuan 030001, People's Republic of China.
Cancer Manag Res. 2020 Jun 19;12:4735-4745. doi: 10.2147/CMAR.S255930. eCollection 2020.
SET has been proven to be an oncogene, which promotes the initiation and progression in several kinds of malignant carcinomas. However, the expression and its functional roles in colorectal carcinoma (CRC) remained unknown.
CRC tissues samples, CRC cell lines and xenograft mouse tumors were used in this study. The mRNA and protein expressions were detected by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), and Western blot (WB), respectively. siRNAs were used to silence the gene expression. Cell viability, cell proliferation, colony formation, and apoptosis were measured by MTS assay, EdU incorporation assay, plated colony formation assay, and flow cytometry, respectively. Western blot was applied to evaluate the levels of Akt, p-Akt, c-Myc and cyclin D1. Xenograft mouse model was performed to observe the role of SET in vivo.
Our results revealed that SET was up-regulated in CRC, and the expression of SET was increased with the development of CRC. SET knockdown in vitro attenuated cell proliferation activity, and increased cell apoptosis in CRC cells. Moreover, the knockdown of SET reduces tumorigenic potential in nude mice. For the mechanism, knockdown of SET promoted the dephosphorylation of Akt, followed by suppressing the translocation of NF-κB to nucleus. In addition, SET knockdown-mediated dephosphorylation of Akt downregulated the expression of c-Myc and Cyclin D1, which inhibited the cell survival in CRC.
Our results indicated that SET promoted cell survival via activating Akt/NF-κB signaling pathway in CRC, which strongly suggested that SET might be a potential therapeutic target in the colorectal carcinoma treatment.
SET已被证明是一种癌基因，可促进多种恶性肿瘤的发生和发展。然而，其在结直肠癌（CRC）中的表达及其功能作用尚不清楚。
本研究使用了CRC组织样本、CRC细胞系和异种移植小鼠肿瘤。分别通过定量实时聚合酶链反应（qRT-PCR）、免疫组织化学（IHC）和蛋白质免疫印迹（WB）检测mRNA和蛋白质表达。使用小干扰RNA（siRNA）沉默基因表达。分别通过MTS法、EdU掺入法、平板集落形成法和流式细胞术检测细胞活力、细胞增殖、集落形成和细胞凋亡。应用蛋白质免疫印迹评估Akt、p-Akt、c-Myc和细胞周期蛋白D1的水平。建立异种移植小鼠模型以观察SET在体内的作用。
我们的结果显示，SET在CRC中上调，且其表达随CRC的发展而增加。体外敲低SET可减弱CRC细胞的增殖活性，并增加细胞凋亡。此外，敲低SET可降低裸鼠的致瘤潜力。机制方面，敲低SET促进了Akt的去磷酸化，随后抑制了NF-κB向细胞核的转位。此外，SET敲低介导的Akt去磷酸化下调了c-Myc和细胞周期蛋白D1的表达，从而抑制了CRC中的细胞存活。
我们的结果表明，SET通过激活CRC中的Akt/NF-κB信号通路促进细胞存活，这强烈提示SET可能是结直肠癌治疗中的一个潜在治疗靶点。
