Abstract
OBJECTIVE To investigate the mechanism of disruptor of telomeric silencing 1-like(DOT1L)on epithelial mesenchymal transition(EMT)in laryngeal squamous cell carcinoma(LSCC)via Notch1 signal pathway.METHODS Fresh tumor tissues and adjacent normal tissues from 30 pathologically confirmed LSCC patients were selected.The positive expression rates of DOT1L and its catalytic product H3K79me3 were detected by immunohistochemistry staining,the relative mRNA expression levels of DOT1L and H3K79me3 were measured by qRT-PCR.The human LSCC cell line TU686 was selected and divided into blank control group,over-expression group,and low-expression group.After 48 hours of cultivation,cell proliferation rate was measured using MTT method,cell apoptosis rate was measured using flow cytometry,and the relative expression levels of Notch1,E-cadherin,N-cadherin,and Vimentin proteins were detected using Western blot.RESULTS 1.Compared with normal tissues adjacent to cancer,the positive expression rates[(41.5±8.9)%vs.(18.3±3.6)%,t=56.963,P＜0.001;(40.5±7.7)%vs.(10.2±2.3)%,t=96.635,P＜0.001]and mRNA expression levels[(0.69±0.13)vs.(0.13±0.09),t=102.302,P＜0.001;(0.42±0.19)vs.(0.09±0.03),t=85.659,P＜0.001]of DOT1L and H3K79me3 in tumor tissues were significantly increased.2.Compared with the blank control group,cell proliferation rate in the over-expression group was significantly higher(t=45.628,P＜0.001),while apoptosis rate was lower(t=40.125,P＜0.001),Notch1,N-cadherin,and Vimentin proteins expressions were increased,E-cadherin was decreased(t=22.524,30.263,45.629,27.859,P＜0.001).The cell proliferation rate in the low expression group was significantly decreased(t=33.427,P＜0.001),but apoptosis rate was increased(t=78.529,P＜0.001),levels of Notch1,N-cadherin,and Vimentin proteins were lower,E-cadherin was higher,too(t=19.864,23.524,28.957,33.426,P＜0.001).CONCLUSION DOT1L is highly expressed in LSCC,affecting the methylation level of histones,thereby regulating cell proliferation,apoptosis,and EMT behavior.DOT1L is expected to become a new site for tumor targeted intervention.关键词
喉肿瘤/癌,鳞状细胞/细胞增殖/细胞凋亡/类端粒沉默干扰体1/Notch1信号通路/上皮间质转化/H3K79me3Key words
Laryngeal Neoplasms/Carcinoma,Squamous Cell/Cell Proliferation/Apoptosis/disruptor of telomeric silencing 1-like/notch1 signaling pathway/epithelial mesenchymal transition/H3K79me3
