Circular RNAs expression profiles in plasma exosomes from early-stage lung adenocarcinoma and the potential biomarkers.

This study aimed to identify differential circular RNA (circRNA) in the plasma exosomes of patients with lung adenocarcinoma (LUAD) using high-throughput sequencing. First, exosomes were isolated using an exosome isolation kit and confirmed by Western blotting, transmission electron microscopy, and NanoSight Assay. Subsequently, plasma circRNA expression profiles were screened by high-throughput sequencing and confirmed by fluorescence quantitative real-time polymerase chain reaction (qRT-PCR) and Sanger sequencing. Finally, the circRNA-miRNA-mRNA network was performed to forecast the potential function of circRNAs. The result of high-throughput sequencing data documented that 182 differentially expressed exosomal circRNAs in all were screened, which included 105 that were upregulated and 78 that were downregulated in LUAD patients plasma compared with controls. The four upregulated circRNAs including circ_0001492, circ_0001346, circ_0000690, and circ_0001439 were identical to the sequencing data by qRT-PCR, and their latent circRNA-miRNA-mRNA interactions were exhibited. Taken together, our study firstly revealed the altered exosomal circRNA expression from plasma samples in patients with LUAD and supports the need for exploring their potential as biomarkers and the pathological effects of lung cancer.

Chen F ，Huang C ，Wu Q ，Jiang L ，Chen S ，Chen L ... -  《-》

Identification of a Plasma Exosomal lncRNA- and circRNA-Based ceRNA Regulatory Network in Patients With Lung Adenocarcinoma.

Exosomes have been established to be enriched with various long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) that exert various biological effects. However, the lncRNA- and circRNA-mediated coexpression competing endogenous RNA (ceRNA) regulatory network in exosomes derived from the plasma of patients with lung adenocarcinoma (LUAD) remains elusive. This study enrolled nine patients with lung adenocarcinoma and three healthy individuals, and the differential expression of messenger RNAs (mRNAs), lncRNAs, and circRNAs was detected using microarray analysis, while microRNAs (miRNAs) were detected through RNA sequencing. Additionally, bioinformatics algorithms were applied to evaluate the lncRNA-miRNA-mRNAs/circRNA-miRNA-mRNA network. Differentially expressed cicRNAs were identified via quantitative reverse transcription polymerase chain reaction (RT-qPCR). A total of 1016 lncRNAs, 1396 circRNAs, 45 miRNAs, and 699 mRNAs were differentially expressed in the plasma exosomes of patients with LUAD compared with healthy controls. Among them, 881 lncRNAs were upregulated and 135 were downregulated, 916 circRNAs were upregulated while 480 were downregulated, 45 miRNAs were upregulated while none were downregulated, and 591 mRNAs were upregulated while 108 were downregulated (p ≤ 0.05, and fold change ≥ 2). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed the biological functions of differentially expressed RNAs. Meanwhile, the RNA networks displayed the regulatory relationship between dysregulated RNAs. Finally, RT-qPCR validated that the expression of circ-0033861, circ-0043273, and circ-0011959 was upregulated in the plasma exosome of patients with LUAD compared to healthy controls (p = 0.0327, p = 0.0002, p = 0.0437, respectively). This study proposed a newly discovered ncRNA-miRNA-mRNA/circRNA-miRNA-mRNA ceRNA network and identified that the expression of circulating circ-0033861, circ-0043273, and circ-0011959 was up-regulated in the plasma exosomes of patients with LUAD, offering valuable insights for exploring the potential function of exosomal noncoding RNA and identifying potential biomarkers for LUAD.

Zhu W ，Zhang H ，Tang L ，Fang K ，Lin N ，Huang Y ，Zhang Y ，Le H ... -  《-》

A two-circular RNA signature as a noninvasive diagnostic biomarker for lung adenocarcinoma.

Liu XX ，Yang YE ，Liu X ，Zhang MY ，Li R ，Yin YH ，Qu YQ ... -  《Journal of Translational Medicine》

Circular RNA expression profile of lung squamous cell carcinoma: identification of potential biomarkers and therapeutic targets.

Emerging evidences indicated that exosomal circular RNAs (circRNAs) could serve as diagnostic biomarkers for cancers. However, the expression profiles and clinical significance of circRNAs in lung squamous cell carcinoma (LUSC) remain largely unknown. Herein, we analyzed circRNAs expression profile in six pairs of plasma exosome samples of LUSC patients using high-throughput sequencing. A total of 252 differentially expressed exosomal circRNAs were identified, including 133 up-regulated circRNAs and 119 down-regulated circRNAs. Subsequently, the circRNAs-miRNAs-mRNAs interaction network was built to investigate potential function of circRNAs. Three up-regulated circRNAs (hsa_circ_0014235, hsa_circ_0025580 and hsa_circ_0026403) were implied to participate in cancer-related pathways. QRT-PCR experiment confirmed the up-regulation of hsa_circ_0014235 and hsa_circ_0025580. Finally, clinical studies indicated that hsa_circ_0014235 and hsa_circ_0025580 could serve as novel diagnostic biomarkers for LUSC. Taken together, our study revealed exosomal circRNAs expression profile in LUSC for the first time and showed the important diagnostic potential for circRNAs in LUSC.

Wang Y ，Zhang H ，Wang J ，Li B ，Wang X ... -  《-》

Circular RNA-microRNA-mRNA network identified circ_0007618 and circ_0029426 as new valuable biomarkers for lung adenocarcinoma.

Zhang Q ，Sun Y ，Wang C ，Shao F ... -  《-》