Xu Jing, Liu Lei, Ma Ranran, Wang Yawen, Chen Xu, Liu Haiting, Ji Youxin, Liu Tiantian, Gao Peng
Key Laboratory for Experimental Teratology of Ministry of Education, Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China.
Department of Pathology, Qilu Hospital, Shandong University, Jinan, China.
Front Oncol. 2021 Jan 11;10:530933. doi: 10.3389/fonc.2020.530933. eCollection 2020.
The aim of this study was to investigate the role of KIF26A in breast cancer.
qRT-PCR and immunohistochemistry were conducted to explore KIF26A expression and functional contribution to breast cancer development. MTS, EDU, colony formation assays, and flow cytometry analysis were conducted to assess cell proliferation characteristics and cell cycle progression. A series of 5'-flanking region deletion plasmids and mutating the binding site, with the luciferase reporter assay, were used to identify the core promotor region of KIF26A. The prediction by software and construction of the transcriptional factor plasmids were used to identify the transcriptional factor. Chromatin immunoprecipitation assay could demonstrate transcriptional factor directly binding to the KIF26A promoter. Human Genome Oligo Microarray Assay and gene ontology (GO) and pathway analyses were used to predict the downstream pathway.
Our results showed that in breast cancer tissues, elevated KIF26A expression was significantly correlated with lymph node metastasis. KIF26A could promote proliferation and G0/G1 phase cell cycle progression in breast cancer cells. The core promoter region of the human KIF26A gene was located upstream of the transcription start site at position -395 to -385. The transcriptional factor E2F1 was shown to activate KIF26A expression. Furthermore, KIF26A was shown to inhibit the expression of p21, then activate CDK-RB-E2Fs pathway. The elevated E2F1 can activate the cell cycle progression and the KIF26A expression, forming feedback loop.
The present study demonstrated that KIF26A, directly upregulated by E2F1, promoted cell proliferation and cell cycle progression CDK-RB-E2Fs feedback loop in breast cancer.
本研究旨在探讨KIF26A在乳腺癌中的作用。
采用qRT-PCR和免疫组织化学方法，探讨KIF26A在乳腺癌发生发展中的表达及功能作用。采用MTS、EDU、集落形成实验和流式细胞术分析评估细胞增殖特性和细胞周期进程。利用一系列5'-侧翼区域缺失质粒和结合位点突变体，通过荧光素酶报告基因实验鉴定KIF26A的核心启动子区域。运用软件预测和构建转录因子质粒来鉴定转录因子。染色质免疫沉淀实验可证明转录因子直接与KIF26A启动子结合。采用人类基因组寡核苷酸微阵列分析以及基因本体（GO）和通路分析来预测下游通路。
我们的结果显示，在乳腺癌组织中，KIF26A表达升高与淋巴结转移显著相关。KIF26A可促进乳腺癌细胞的增殖和G0/G1期细胞周期进程。人类KIF26A基因的核心启动子区域位于转录起始位点上游-395至-385位。转录因子E2F1可激活KIF26A的表达。此外，KIF26A可抑制p21的表达，进而激活CDK-RB-E2Fs通路。升高的E2F1可激活细胞周期进程和KIF26A的表达，形成反馈环。
本研究表明，由E2F1直接上调的KIF26A在乳腺癌中通过CDK-RB-E2Fs反馈环促进细胞增殖和细胞周期进程。
