Department of Thoracic and Cardiovascular Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China.
Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
J Cell Physiol. 2019 Aug;234(8):13735-13746. doi: 10.1002/jcp.28053. Epub 2019 Jan 8.
Recently, pseudogenes have emerged as critical regulators in the onset of human neoplasia. Here, we present a comprehensive analysis of pseudogene alterations at transcriptional levels in lung adenocarcinoma (LUAD) from The Cancer Genome Atlas. By combinations of differential expression analysis, survival analysis, and univariate and multivariable Cox proportional hazards regression models, we identified four dysregulated pseudogenes, whose expression level was closely related to LUAD patients' prognosis and the four pseudogene signature could act as an independent prognostic indicator for LUAD patients. We further characterized CHIAP2, one of those four pseudogenes, whose expression level was the most closely linked to LUAD patients' prognosis. Consistent with our analysis, the expression of CHIAP2 was abnormally downregulated in LUAD tissues compared with that in normal tissues in our 50 pairs of clinical samples. Functional assays demonstrated that upregulation of CHIAP2 significantly impaired cell proliferation and invasion. After performing RNA sequencing (RNA-seq) and small RNA-seq between CHIAP2 overexpression and negative control LUAD cell lines, we identified differentially expressed messenger RNAs and microRNAs (miRNAs), among which six miRNAs were downregulated. Target genes of six downregulated miRNAs were predicted with online miRNA target prediction tools and significant pathways including the WNT signal pathway were identified with Gene Set Enrichment Analysis. By combining predictor genes of six downregulated miRNAs and dysregulated genes of the WNT pathway, we inferred that overexpression of CHAP2 may inhibit LUAD cell proliferation and invasion via modulation of NFATC2 or GSK3B (WNT signal pathway) targeted by miR-3614-5p or miR-873-3p.
最近，假基因已成为人类肿瘤发生的关键调控因子。在这里，我们对癌症基因组图谱中的肺腺癌（LUAD）的转录水平的假基因改变进行了全面分析。通过差异表达分析、生存分析以及单变量和多变量 Cox 比例风险回归模型的组合，我们确定了四个失调的假基因，其表达水平与 LUAD 患者的预后密切相关，并且这四个假基因特征可以作为 LUAD 患者的独立预后指标。我们进一步对这四个假基因中的一个 CHIAP2 进行了特征描述，其表达水平与 LUAD 患者的预后最密切相关。与我们的分析一致，在我们的 50 对临床样本中，CHIAP2 的表达水平在 LUAD 组织中明显低于正常组织。功能测定表明，CHIAP2 的上调显著抑制了细胞增殖和侵袭。在 CHIAP2 过表达和阴性对照 LUAD 细胞系之间进行 RNA 测序（RNA-seq）和小 RNA-seq 后，我们鉴定了差异表达的信使 RNA 和 microRNA（miRNA），其中六个 miRNA 下调。六个下调 miRNA 的靶基因使用在线 miRNA 靶预测工具进行预测，使用基因集富集分析鉴定了显著的途径，包括 WNT 信号途径。通过将六个下调 miRNA 的预测基因和 WNT 途径的失调基因结合起来，我们推断 CHAP2 的过表达可能通过 miR-3614-5p 或 miR-873-3p 靶向的 NFATC2 或 GSK3B（WNT 信号途径）来抑制 LUAD 细胞的增殖和侵袭。
