DataSheet1_NcRNA-mediated upregulation of CAMK2N1 is associated with poor prognosis and tumor immune infiltration of gastric cancer.PDF

Gastric cancer (GC) is still notorious for its poor prognosis and aggressive characteristics. Though great developments have been made in diagnosis and therapy for GC, the prognosis of patient is still perishing. In this study, differentially expressed genes (DEGs) in GC were first screened using three Gene Expression Omnibus (GEO) datasets (GSE13911, GSE29998, and GSE26899). Second, The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data were used to validate expression of these DEGs and perform survival analysis. We selected seven candidate genes (CAMK2N1, OLFML2B, AKR7A3, CYP4X1, FMO5, MT1H, and MT1X) to carry out the next analysis. To construct the ceRNA network, we screened the most potential upstream ncRNAs of the candidate genes. A series of bioinformatics analyses, including expression analysis, correlation analysis, and survival analysis, revealed that the SNHG10–hsa-miR-378a-3p might be the most potential regulatory axis in GC. Then, the expression of CAMK2N1, miR-378a-3p, and SNHG10 was verified in GC cell lines (GES-1, MGC-803, BGC-823, HGC-27, MKN-45, and AGS) by qRT-PCR and Western blotting. We found that SNHG10 and CAMK2N1 were highly expressed in gastric cancer lines, and the miR-378a-3p was lowly expressed in BGC-823, HGC-27, and MKN-45. Furthermore, CAMK2N1 levels were significantly negatively associated with tumor immune cell infiltration, biomarkers of immune cells, and immune checkpoint expression. In summary, our results suggest that the ncRNA-mediated high expression of CAMK2N1 is associated with poor prognosis and tumor immune infiltration of GC.

胃癌（Gastric cancer, GC）仍以预后不良、侵袭性强的特性为人诟病。尽管胃癌的诊断与治疗领域已取得长足进展，但患者的预后依旧不容乐观。本研究首先利用3组基因表达综合数据库（Gene Expression Omnibus, GEO）数据集（GSE13911、GSE29998及GSE26899）筛选胃癌组织中的差异表达基因（differentially expressed genes, DEGs）；其次借助癌症基因组图谱（The Cancer Genome Atlas, TCGA）与基因型-组织表达数据库（Genotype-Tissue Expression, GTEx）的数据，对上述差异表达基因的表达情况进行验证，并开展生存分析。我们最终筛选出7个候选基因（CAMK2N1、OLFML2B、AKR7A3、CYP4X1、FMO5、MT1H及MT1X）用于后续分析。为构建内源竞争RNA（competing endogenous RNA, ceRNA）网络，我们进一步筛选了候选基因最具潜力的上游非编码RNA（non-coding RNAs, ncRNAs）。一系列生物信息学分析（涵盖表达分析、相关性分析与生存分析）结果显示，SNHG10–hsa-miR-378a-3p可能是胃癌中最具潜力的调控轴。随后，我们通过实时定量聚合酶链式反应（quantitative real-time polymerase chain reaction, qRT-PCR）与蛋白质印迹法（Western blotting），在胃癌细胞系（GES-1、MGC-803、BGC-823、HGC-27、MKN-45及AGS）中验证了CAMK2N1、miR-378a-3p及SNHG10的表达水平。研究发现，SNHG10与CAMK2N1在胃癌细胞系中呈高表达，而miR-378a-3p在BGC-823、HGC-27及MKN-45细胞系中呈低表达。此外，CAMK2N1的表达水平与肿瘤免疫细胞浸润、免疫细胞生物标志物及免疫检查点表达均呈显著负相关。综上，本研究结果表明，非编码RNA介导的CAMK2N1高表达与胃癌患者的不良预后及肿瘤免疫浸润密切相关。