CDYL promotes the chemoresistance of small cell lung cancer by regulating H3K27 trimethylation at the CDKN1C promoter
CDYL promotes the chemoresistance of small cell lung cancer by regulating H3K27 trimethylation at the CDKN1C promoter
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CDYL通过调节CDKN1C启动子处的H3K27三甲基化促进小细胞肺癌的化疗耐药
DOI：
10.7150/thno.33680
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发表时间：
2019
期刊：
影响因子：
12.4
通讯作者：
Zhang Jian
中科院分区：
文献类型：
--
作者：
Qiu Zhengang;Zhu Weiliang;Meng Hui;Tong Lihua;Li Xi;Luo Peng;Yi Lilan;Zhang Xiaoli;Guo Linlang;Wei Ting;Zhang Jian
理由：化疗耐药经常发生在小细胞肺癌（SCLC）患者中，并导致预后不佳。然而，这一过程背后的机制在很大程度上仍不清楚。方法：采用Western blotting、免疫组织化学、细胞计数试剂盒-8、流式细胞术、致瘤性实验等方法检测y -样色域（CDYL）对SCLC化疗耐药的影响，并采用mRNA测序、染色质免疫沉淀- qpcr、电泳迁移量移位、共免疫沉淀、GST拉下实验、亚硫酸酯测序PCR、ELISA和生物信息学分析等方法研究其潜在机制。结果：CDYL在化疗耐药SCLC患者组织中高水平表达，CDYL水平升高与临床分期晚期和预后不良相关。此外，CDYL的表达在化疗耐药的SCLC细胞中显著上调。使用功能增益和功能丧失方法，我们发现CDYL在体外和体内促进SCLC的化疗耐药。从机制上讲，CDYL通过沉默其下游介质细胞周期蛋白依赖性激酶抑制剂1C （CDKN1C）来促进SCLC化疗耐药。进一步的机制研究表明，CDYL招募zeste同源物2的增强子（EZH2）来调节CDKN1C启动子区域组蛋白3 （H3K27me3）中赖氨酸27的三甲基化，并促进转录沉默。因此，EZH2抑制剂GSK126可以抑制CDKN1C，降低SCLC中cdyl诱导的化疗耐药。主要结论：基于这些结果，CDYL/EZH2/CDKN1C轴促进SCLC的化疗耐药，这些标志物是克服SCLC患者化疗耐药的有希望的治疗靶点。
Rationale: Chemoresistance frequently occurs in patients with small cell lung cancer (SCLC) and leads to a dismal prognosis. However, the mechanisms underlying this process remain largely unclear. Methods: The effects of chromodomain Y-like (CDYL) on chemoresistance in SCLC were determined using Western blotting, immunohistochemistry, cell counting kit-8 assays, flow cytometry, and tumorigenicity experiments, and the underlying mechanisms were investigated using mRNA sequencing, chromatin immunoprecipitation-qPCR, electrophoretic mobility shift assays, co-immunoprecipitation, GST pull down assays, bisulfite sequencing PCR, ELISA, and bioinformatics analyses. Results: CDYL is expressed at high levels in chemoresistant SCLC tissues from patients, and elevated CDYL levels correlate with an advanced clinical stage and a poor prognosis. Furthermore, CDYL expression is significantly upregulated in chemoresistant SCLC cells. Using gain- and loss-of-function methods, we show that CDYL promotes chemoresistance in SCLC in vitro and in vivo. Mechanistically, CDYL promotes SCLC chemoresistance by silencing its downstream mediator cyclin-dependent kinase inhibitor 1C (CDKN1C). Further mechanistic investigations showed that CDYL recruits the enhancer of zeste homolog 2 (EZH2) to regulate trimethylation of lysine 27 in histone 3 (H3K27me3) at the CDKN1C promoter region and promotes transcriptional silencing. Accordingly, the EZH2 inhibitor GSK126 de-represses CDKN1C and decreases CDYL-induced chemoresistance in SCLC. Principal conclusions: Based on these results, the CDYL/EZH2/CDKN1C axis promotes chemoresistance in SCLC, and these markers represent promising therapeutic targets for overcoming chemoresistance in patients with SCLC.