Background/Aims: Circular RNAs (circRNAs) are key regulators in the development and progression of human cancers, however its role in non-small cell lung cancer (NSCLC) tumorigenesis is not well understood. The aim of this study is to identify the expression level of circPVT1 in NSCLC and further investigated its functional relevance with NSCLC progression both in vitro and in vivo. Methods: Quantative real-time PCR was used for the measurement of circPVT1 in NSCLC specimens and cell lines. Fluorescence in situ hybridization analysis (FISH) assay was used for the identification of sublocation of circPVT1 in NSCLC cells. Bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation (RIP) were performed to verify the binding of c-Fos at circPVT1 promoter region, and the direct interaction between circPVT1 and miR-125b. Gain- or loss-function assays were performed to evaluate the effects of circPVT1 on cell proliferation and invasion. Western blot and immunohistochemistry assays were performed to detect the protein levels involved in E2F2 pathway. Results: We found that circPVT1 was upregulated in NSCLC specimens and cells. The transcription factor c-Fos binded to the promoter region of circPVT1, resulting in the overexpression of circPVT1 in NSCLC. Knockdown of circPVT1 suppressed NSCLC cell proliferation, migration and invasion, and increased apoptosis. In addition, circPVT1 mediated NSCLC progression via the regulation of E2F2 signaling pathway. More importantly, circPVT1 was predominantly abundant in the cytoplasm of NSCLC cells, and circPVT1 could serve as a competing endogenous RNA to regulate E2F2 expression and tumorigenesis in a miR-125b-dependent manner, which is further verified by using an in vivo xenograft model. Conclusion: circPVT1 promotes NSCLC cell growth and invasion, and may serve as a promising therapeutic target for NSCLC patients. Therefore, silence of circPVT1 could be a future direction to develop a novel treatment strategy.

Background: Exosomes are cell-derived vesicles and bear a specific set of nucleic acids including DNA (exoDNA). Thus, this study is to explore whether exoDNA in malignant pleural effusions (MPEs) could be a novel DNA source for mutation detection of epidermal growth factor receptor (EGFR).Methods: In this study, 52 lung adenocarcinoma patients were enrolled, and EGFR mutation status was detected with tumor tissues as well as cell blocks and exosomes in MPEs. The sensitivity, specificity and consistency of EGFR detection using exosomes were evaluated, compared with gene detection using tumor tissues and cell blocks. And the clinical response of patients who were detected as EGFR mutation in exosomes and treated with EGFR tyrosine kinase inhibitor (EGFR-TKI) was explored.Results: Gene detection using exosomes showed sensitivity of 100%, specificity of 96.55% and coincidence rate of 98.08% (Kappa = 0.961, P < 0.001), compared with detection using tumor tissues and cell blocks. After EGFR-TKI treatment, patients detected as EGFR mutation by exosomes showed efficacy rate of 83% and disease control rate of 100%. And patients who were detected as wild type in tumor tissues or cell blocks but EGFR mutation in exosomes turned up as PR or SD.Conclusions: These results demonstrated that exoDNA in MPEs could be used as a DNA source for EGFR detection in lung adenocarcinoma.

Circulating tumor DNA (ctDNA) can be identified in the peripheral blood of patients and harbors the genomic alterations found in tumor tissues, which provides a noninvasive approach for detection of gene mutations. We conducted this meta-analysis to investigate whether ctDNA can be used for monitoring KRAS gene mutations in colorectal cancer (CRC) patients. Medline, Embase, Cochrane Library and Web of Science were searched for the included eligible studies in English, and data were extracted for statistical analysis according to the numbers of true-positive (TP), true-negative (TN), false-positive (FP) and false-negative (FN) cases. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated, and the area under the receiver operating characteristic curve (AUROC) was used to evaluate the diagnostic performance. After independent searching and reviewing, 21 studies involving 1,812 cancer patients were analyzed. The overall sensitivity, specificity and DOR were 0.67 (95% confidence interval [CI] =0.55–0.78), 0.96 (95% CI =0.93–0.98) and 53.95 (95% CI =26.24–110.92), respectively. The AUROC was 0.95 (95% CI =0.92–0.96), which indicated the high diagnostic accuracy of ctDNA. After stratified analysis, we found the higher diagnostic accuracy in subgroup of patients detected in blood sample of plasma. The ctDNA may be an ideal source for detection of KRAS gene mutations in CRC patients with high specificity and diagnostic value.

The gold standard of natural nacre provides the inspiration for assembling bioinspired nanocomposites.

RNA interference combined with conventional chemotherapy is more effective against colon cancer.