ObjectiveTo explore the mechanism of dihydrouridine synthase 4-like (DUS4L) on the development of lung adenocarcinoma (LUAD).MethodsThe RNA-seq expression data of LUAD was downloaded from The Cancer Genome Atlas (TCGA), and the relationship between its clinical pathological characteristics and DUS4L mRNA expression was evaluated. The effect of DUS4L knockdown on the proliferation of A549 cells was detected by EDU proliferation assay. The gene expression profile of lung adenocarcinoma A549 cells in the DUS4L knockdown group (KD group) and control group (NC group) was detected by transcriptome sequencing technique. The differential genes were screened by DESeq2. ClusterProfiler was used to perform GO functional enrichment analysis of differential genes.ResultsThe expression of DUS4L mRNA in LUAD tissues was higher than that in normal tissues, and the up-regulation of DUS4L was related to the clinical pathological characteristics of LUAD patients. EDU proliferation assay suggested that knocking down DUS4L could inhibit the proliferation of A549 cells. A total of 456 differential genes were screened, including 289 up-regulated genes and 167 down-regulated genes [|log2(fold change)|>1 and Padj<0.05]. STC2 and TRIB3 were significantly down-regulated (P<0.05). Differential genes were mainly involved in the production of interleukin-8, angiogenesis, vascular endothelial cell proliferation and other biological pathways.ConclusionDUS4L can widely regulate the gene expression of LUAD cells, which provides a new idea for further studying the function and role of DUS4L in the occurrence and development of LUAD and finding new therapeutic targets for LUAD.
ObjectiveTo systematically evaluate the expression of programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) in esophageal squamous cell carcinoma and its relationship with prognosis.MethodsThe literature from PubMed, EMbase, The Cochrane Library, Web of Science, CNKI and Wanfang data from inception to February 22, 2020 was searched by computer. Data were extracted and the quality of literature was evaluated using RevMan 5.3 software for meta-analysis. Egger's and Begg's tests were used to evaluate publication bias, and Stata 15.1 software was used for sensitivity analysis.Results A total of 16 articles were included, and there were 3 378 patients with esophageal squamous cell carcinoma. The methodological index for nonrandomized studies (MINORS) scores were all 12 points and above. The meta-analysis results showed that the positive expression rates of PD-1 and PD-L1 in tumor cells were 37.8% (190/504) and 41.7% (1 407/3 378), respectively. The positive expression of PD-L1 in tumor immune infiltrating cells was 41.7% (412/987). The overall survival (OS) of the tumor cell with high PD-L1 expression was lower than that with low PD-LI expression (HR=1.30, 95%CI 1.01-1.69, P=0.04). The OS of the tumor immune infiltrating cell with high PD-L1 expression was significantly higher than that with low PD-LI expression (HR=0.65, 95%CI 0.53-0.80, P<0.0001).ConclusionPD-L1 has a high expression rate in esophageal squamous cell carcinoma and is an important factor for the prognosis of esophageal squamous cell carcinoma.