Xiangxiang Ding

BACKGROUND: Circulating tumor DNA (ctDNA) has offered a minimally invasive and feasible approach for detection of EGFR mutation for non-small cell lung cancer (NSCLC). This meta-analysis was designed to investigate the diagnostic value of ctDNA, compared with current "gold standard," tumor tissues. METHODS: We searched PubMed, EMBASE, Cochrane Library, and Web of Science to identify eligible studies that reported the sensitivity and specificity of ctDNA for detection of EGFR mutation status in NSCLC. Eligible studies were pooled to calculate the pooled sensitivity, specificity, and diagnostic odds ratio (DOR). The summary ROC curve (SROC) and area under SROC (AUSROC) were used to evaluate the overall diagnostic performance. RESULTS: Twenty-seven eligible studies involving 3,110 participants were included and analyzed in our meta-analysis, and most studies were conducted among Asian population. The pooled sensitivity, specificity, and DOR were 0.620 [95% confidence intervals (CI), 0.513-0.716), 0.959 (95% CI, 0.929-0.977), and 38.270 (95% CI, 21.090-69.444), respectively. The AUSROC was 0.91 (95% CI, 0.89-0.94), indicating the high diagnostic performance of ctDNA. CONCLUSION: ctDNA is a highly specific and effective biomarker for the detection of EGFR mutation status. IMPACT: ctDNA analysis will be a key part of personalized cancer therapy of NSCLC.

Noncoding RNA play important roles in various biological processes and diseases, including cancer. The expression profile of circular RNA (circRNA) has not been systematically investigated in lung adenocarcinoma (LUAD). In this study, we performed genomewide transcriptome profiling of coding genes, long noncoding RNA (lncRNA), and circRNA in paired LUAD and nontumor tissues by ribosomal RNA-depleted RNA sequencing. The detected reads were first mapped to the human genome to analyze expression of coding genes and lncRNA, while the unmapped reads were subjected to a circRNA prediction algorithm to identify circRNA candidates. We identified 1282 differentially expressed coding genes in LUAD. Expression of 19 023 lncRNA was detected, of which 244 lncRNAs were differentially expressed in LUAD. AFAP1-AS1, BLACAT1, LOC101928245, and FENDRR were most differentially expressed lncRNAs in LUAD. Also identified were 9340 circRNA candidates with ≥ 2 backspliced, including 3590 novel circRNA transcripts. The median length of circRNA was ~ 530 nt. CircRNA are often of low abundance, and more than half of circRNAs we identified had < 10 reads. Agarose electrophoresis and Sanger sequencing were used to confirm that four candidate circRNA were truly circular. Our results characterized the expression profile of coding genes, lncRNA, and circRNA in LUAD; 9340 circRNAs were detected, demonstrating that circRNA are widely expressed in LUAD. Database: The raw RNA sequencing data have been submitted to Gene Expression Omnibus (GEO) database and can be accessed with the ID GEO: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE104854.

BACKGROUND: Single nucleotide polymorphisms (SNPs) occurred in pre-microRNAs or targets of microRNAs (miRs) may contribute to cancer risks. Since 2007, many studies have investigated the association between common SNPs located on hsa-miR-499 (rs3746444) and cancer risks; however, the results were inconclusive. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a meta-analysis of 12 studies that included 5765 cases and 7076 controls to identify the strength of association. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of association. Overall, individuals with the variant AG (OR = 1.215, 95% CI: 1.027, 1.437; P(heterogeneity)<0.01) and AG/GG (OR = 1.227, 95% CI: 1.046, 1.439; P(heterogeneity)<0.01) genotypes were associated with a significantly increased risk of cancer than those with wild AA genotype. Sub-group analysis revealed that the variant AG (OR = 1.411, 95% CI: 1.142, 1.745; P(heterogeneity) = 0.01) and AG/GG (OR = 1.413, 95% CI: 1.163, 1.717, P(heterogeneity) = 0.01) genotypes still showed an increased risk of cancer in Asians; however, a trend of reduced risk of cancer was observed in Caucasians (AG vs. AA: OR = 0.948, 955 CI: 0.851, 1.057, P(heterogeneity) = 0.12; AG/GG vs. AA: OR = 0.959, 95% CI: 0.865, 1.064; P(heterogeneity) = 0.19). Meta-regression showed that ethnicity (p = 0.048) and sample size (p = 0.02) but not cancer types (p = 0.89) or source of control (p = 0.97) were the sources of heterogeneity. CONCLUSIONS: These meta-analysis results suggest that hsa-miR-499 polymorphism rs3746444 is associated with a significantly increased risk of cancer, especially in Asian populations.

hybridization were performed to detect AFAP1-AS1 expression in frozen tissues and tissue microarrays, respectively. The results revealed that the expression level of AFAP1-AS1 was significantly increased in tumor tissues, compared with the paired non-cancerous tissues. It was also determined that the AFAP1-AS1 expression level was higher in patients with lymph node metastasis than those without lymph node metastasis (P=0.014). Kaplan-Meier analysis was conducted to evaluate the overall survival of patients with NSCLC and different expression levels of AFAP1-AS1, and the results indicated that patients with high AFAP1-AS1 expression had a reduced survival time, compared with those with low AFAP1-AS1 expression (P=0.011). Cox regression analysis was also performed to analyze the prognostic value of lncRNA AFAP1-AS1. The obtained data demonstrated that lncRNA AFAP1-AS1 was an unfavorable prognostic biomarker for NSCLC (HR: 3.12, 95% CI (1.05-9.25), P=0.040). In conclusion, it was demonstrated that lncRNA AFAP1-AS1 is overexpressed in NSCLC and an unfavorable biomarker for patients with NSCLC.