Zhang Haiyan, Zhang Zhuo, Wang Dayu
Department of Gastrointestinal Colorectal and Anal Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China.
Department of Urology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China.
Cancer Manag Res. 2019 Sep 20;11:8589-8602. doi: 10.2147/CMAR.S186002. eCollection 2019.
Long noncoding RNAs (lncRNAs) play an important role in gastric cancer. In this study, we aimed to uncover the epigenetic regulatory mechanism of lncRNA KCNK15-AS1 in gastric cancer progression.
Forty patients were included in the study. The expression of KCNK15-AS1 was detected by real-time PCR (RT-PCR), the promoter of KCNK15-AS1 was detected by methylation-specific PCR, and the luciferase assay was performed to detect the relationship between KCNK15-AS1 and miR-21. The relationship of the proteins was explored by an RNA pull-down assay and RNA immunoprecipitation. Chromatin immunoprecipitation was performed to detect the relationship between the promoter and the protein.
The expression of KCNK15-AS1 was lower in the tumor tissue compared to the normal tissue. KCNK15-AS1 interacted with miR-21. Both the overexpression of KCNK15-AS1 and the knockdown of the expression of miR-21 inhibited proliferation and promoted apoptosis and decreased the level of MMP-9, bcl-2, and MMP-2 but increased the level of Bax. In addition, the methylation of KCNK15-AS1 was detected in the tumor tissue but was not detected in the normal tissue. Treatment with 5-azacytidine and chidamide decreased the level of DNMT1 and HDAC1 and increased the level of KCNK15-AS1. The RNA pull-down and RNA immunoprecipitation results showed that KCNK15-AS1 interacted with DNMT1 and HDAC1. The ChIP-seq result showed that the promoter of MAPK interacted with DNMT1, and the promoter of AKT and STAT5 interacted with HDAC1.
In this study, we identified two regulatory axes, namely KCNK15-AS1-DNMT1-MAPK and KCNK15-AS1-HDAC1-AKT, which were associated with gastric cancer progression. Chidamide and 5-azacytidine might provide new modes for treating gastric cancer.
长链非编码RNA（lncRNA）在胃癌中发挥重要作用。在本研究中，我们旨在揭示lncRNA KCNK15-AS1在胃癌进展中的表观遗传调控机制。
本研究纳入40例患者。采用实时荧光定量PCR（RT-PCR）检测KCNK15-AS1的表达，甲基化特异性PCR检测KCNK15-AS1的启动子，荧光素酶报告基因检测法检测KCNK15-AS1与miR-21之间的关系。通过RNA下拉试验和RNA免疫沉淀探索蛋白质之间的关系。进行染色质免疫沉淀检测启动子与蛋白质之间的关系。
与正常组织相比，肿瘤组织中KCNK15-AS1的表达较低。KCNK15-AS1与miR-21相互作用。KCNK15-AS1的过表达和miR-21表达的敲低均抑制增殖、促进凋亡，并降低MMP-9、bcl-2和MMP-2的水平，但增加Bax的水平。此外，在肿瘤组织中检测到KCNK15-AS1的甲基化，而在正常组织中未检测到。用5-氮杂胞苷和西达本胺处理可降低DNMT1和HDAC1的水平，并增加KCNK15-AS1的水平。RNA下拉和RNA免疫沉淀结果表明，KCNK15-AS1与DNMT1和HDAC1相互作用。染色质免疫沉淀测序结果表明，MAPK启动子与DNMT1相互作用，AKT和STAT5启动子与HDAC1相互作用。
在本研究中，我们鉴定出两条与胃癌进展相关的调控轴，即KCNK15-AS1-DNMT1-MAPK和KCNK15-AS1-HDAC1-AKT。西达本胺和5-氮杂胞苷可能为胃癌治疗提供新的模式。
