Chongqing Key Laboratory of Molecular Oncology and Epigenetics, Τhe First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
Department of Oncology, Τhe Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China.
Int J Oncol. 2018 Sep;53(3):961-972. doi: 10.3892/ijo.2018.4446. Epub 2018 Jun 19.
Several studies have recently reported that KRAB zinc finger protein 382 (ZNF382) is downregulated in multiple carcinoma types due to promoter methylation. The exact role of ZNF382 in gastric carcinogenesis, however, remains elusive. In this study, we investigated the alterations and functions of ZNF382 in the pathogenesis of gastric cancer (GC). Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), quantitative (real-time) PCR (qPCR) and immunohistochemistry were carried out to detect the expression patterns of ZNF382 in GC cell lines and gastric tissue samples. Furthermore, its methylation status in GC cell lines, tumor tissues and adjacent non-tumor tissues was detected by methylation-specific PCR (MSP). We observed that ZNF382 was silenced due to promoter methylation in MKN45 and SGC7901 cell lines, and that its silencing could be reversed with 5-aza-2'-deoxycytidine, indicating that its downregulation in GC is due to promoter methylation. In addition, the ectopic expression of ZNF382 significantly inhibited gastric tumor cell clonogenicity, proliferation, migration and epithelial-mesenchymal transition (EMT) through the induction of apoptosis. ZNF382 expression downregulated the expression of SNAIL, Vimentin, Twist, NOTCH1, NOTCH2, NOTCH3, NOTCH4, HES-1, JAG1, matrix metalloproteinase (MMP)2 and MMP11, as well as that of the stem cell markers, NANOG, octamer-binding transcription factor 4 (OCT4) and SOX2. ZNF382 also upregulated the expression of E-cadherin. On the whole, the findings of this study suggest that ZNF382 functions as a tumor suppressor in GC cells, but is frequently methylated in both GC cell lines and primary gastric tumors. ZNF382 can reverse the EMT process in GC cells through NOTCH signaling. Our findings further illustrate the molecular pathogenesis of GC and establish potential biomarkers for this type of cancer.
最近有几项研究报道，KRAB 锌指蛋白 382（ZNF382）由于启动子甲基化而在多种癌类型中下调。然而，ZNF382 在胃癌发生中的确切作用仍然难以捉摸。在这项研究中，我们研究了 ZNF382 在胃癌发病机制中的改变和功能。通过半定量逆转录-聚合酶链反应（RT-PCR）、定量（实时）PCR（qPCR）和免疫组织化学检测 ZNF382 在 GC 细胞系和胃组织样本中的表达模式。此外，通过甲基化特异性 PCR（MSP）检测 ZNF382 在 GC 细胞系、肿瘤组织和相邻非肿瘤组织中的甲基化状态。我们观察到 ZNF382 在 MKN45 和 SGC7901 细胞系中由于启动子甲基化而沉默，并且其沉默可以通过 5-氮杂-2'-脱氧胞苷逆转，表明 GC 中的下调是由于启动子甲基化。此外，ZNF382 的异位表达通过诱导细胞凋亡显著抑制胃肿瘤细胞的克隆形成、增殖、迁移和上皮-间充质转化（EMT）。ZNF382 表达下调 SNAIL、波形蛋白、Twist、NOTCH1、NOTCH2、NOTCH3、NOTCH4、HES-1、JAG1、基质金属蛋白酶（MMP）2 和 MMP11 的表达，以及干细胞标志物 NANOG、八聚体结合转录因子 4（OCT4）和 SOX2 的表达。ZNF382 还上调了 E-钙粘蛋白的表达。总的来说，这项研究的结果表明，ZNF382 在 GC 细胞中作为肿瘤抑制因子发挥作用，但在 GC 细胞系和原发性胃肿瘤中经常发生甲基化。ZNF382 可以通过 NOTCH 信号通路逆转 GC 细胞中的 EMT 过程。我们的研究结果进一步说明了 GC 的分子发病机制，并为这种癌症建立了潜在的生物标志物。
