Hypermethylation of miR-338-3p and Impact of its Suppression on Cell Metastasis Through N-Cadherin Accumulation at the Cell -Cell Junction and Degradation of MMP in Gastric Cancer
Hypermethylation of miR-338-3p and Impact of its Suppression on Cell Metastasis Through N-Cadherin Accumulation at the Cell -Cell Junction and Degradation of MMP in Gastric Cancer
复制标题
胃癌中 miR-338-3p 的高甲基化及其通过细胞-细胞连接处 N-钙粘蛋白积累和 MMP 降解抑制细胞转移的影响
DOI：
10.1159/000494153
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发表时间：
2018-01-01
影响因子：
--
通讯作者：
Huang, Chen
中科院分区：
文献类型：
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作者：
Guo, Bo;Zhang, Jing;Huang, Chen
背景/目的：MicroRNA（miRNAs）在人类肿瘤发生和癌症进展中的作用已得到充分研究。我们前期的研究发现miR-338- 3 p在人胃癌中表达下调。然而，这种失调的原因在很大程度上仍不清楚。方法：采用亚硫酸氢盐序列分析法检测miR-338- 3 p启动子区甲基化状态。细胞创伤愈合和transwell实验检测细胞迁移和细胞相互作用的能力。双荧光素酶报告基因用于验证生物信息学预测的miR-338- 3 p靶基因。使用Western印迹、RNA干扰和免疫荧光（IF）来评估MMP的表达和N-cadherin的定位，以确定miR-338- 3 p诱导的抗肿瘤作用的潜在机制。结果：miR-338- 3 p在胃癌中表观遗传学上被沉默，这种表达缺失与胃癌的Borrmann分期显著相关。在BGC-823细胞中恢复miR-338- 3 p表达抑制细胞迁移和侵袭。此外，Ras相关蛋白（Rab-14）和Hedgehog酰基转移酶（Hhat）被鉴定为miR-338- 3 p的直接靶点。miR-338- 3 p和小干扰RNA的强制表达均诱导Rab 14介导的细胞-细胞连接处的N-钙粘蛋白积聚或Hhat相关的基质金属蛋白酶（MMP）降解，这可能强调了GC中miR-338- 3 p缺失导致的转移缺陷。结论：这些数据表明miR-338- 3 p在GC中具有抑癌作用，其CpG岛的高甲基化状态可能是治疗GC的一种新的潜在策略。
Background/Aims: MicroRNAs (miRNAs) have been well studied in human carcinogenesis and cancer progression. Our previous study showed the down-regulation of miR-338-3p expression in human gastric cancer (GC). However, the reasons of this dysregulation remain largely unclear. Methods: Bisulfite sequence analysis was performed to explore the methylation status of the promoter region of miR-338-3p. Cell wound-healing and transwell assays were performed to examine the capacity of cell migration and cell interaction. A dual-luciferase reporter was used to validate the bioinformatics-predicted target gene of miR-338-3p. Western blotting, RNA interference, and immunofluorescence (IF) were used to evaluate the expression of MMPs and the location of N-cadherin to determine the mechanism underlying miR-338-3p-induced anti-tumor effects. Results: miR-338-3p was epigenetically silenced, and this loss of expression was significantly correlated with the Borrmann Stage in GC. Restoring miR-338-3p expression in BGC-823 cells inhibited cell migration and invasion. Moreover, Ras-related protein (Rab-14) and Hedgehog acyltransferase (Hhat) were identified as direct targets of miR-338-3p. Both enforced expression of miR-338-3p and small interfering RNA induced Rab14-mediated accumulation of N-cadherin in the cell -cell junctions or Hhat-associated matrix metalloproteinase (MMP) degradation, which may underline the metastasis defects caused by loss of miR-338-3p in GC. Conclusion: These data indicate that miR-338-3p functions as a tumor suppressor in GC, and that the hypermethylation status of its CpG island might be a novel potential strategy for treating GC.