Analyzing the Interactions of mRNAs and ncRNAs to Predict Competing Endogenous RNA Networks in Osteosarcoma Chemo-Resistance.

Chemo-resistance is a huge obstacle encountered in the osteosarcoma (OS) treatment. Protein-coding mRNAs, as well as non-coding RNAs (ncRNAs), including long ncRNA (lncRNA), circular RNA (circRNA), and microRNA (miRNA), have been demonstrated to play an essential role in the regulation of cancer biology. However, the comprehensive expression profile and competing endogenous RNA (ceRNA) regulatory network between mRNAs and ncRNAs in the OS chemo-resistance still remain unclear. In the current study, we developed whole-transcriptome sequencing (RNA sequencing [RNA-seq]) in the three paired multi-drug chemo-resistant and chemo-sensitive OS cell lines to comprehensively identify differentially expressed lncRNAs, circRNAs, miRNAs, and mRNAs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed for mRNAs with significantly different expression. Then the ceRNA networks combining lncRNAs, circRNAs, miRNAs, and mRNAs were predicted and constructed on the basis of the authoritative miRanda and TargetScan databases combined with the widely accepted vital drug resistance-related genes and signal transduction pathways. In addition, two constructed ceRNA regulatory pathways, lncRNAMEG3/hsa-miR-200b-3p/AKT2 and hsa_circ_0001258/hsa-miR-744-3p/GSTM2, were randomly selected and validated by real-time qPCR, RNA immunoprecipitation (RIP), RNA pull-down assay, and dual luciferase reporter gene system. Taken together, our findings may provide new evidence for the underlying mechanism of OS chemo-resistance and uncover some novel targets for reversing it.

Zhu KP ，Zhang CL ，Ma XL ，Hu JP ，Cai T ，Zhang L ... -  《-》

Comprehensive analysis of the whole coding and non-coding RNA transcriptome expression profiles and construction of the circRNA-lncRNA co-regulated ceRNA network in laryngeal squamous cell carcinoma.

Recently, accumulating evidence has demonstrated that non-coding RNAs (ncRNAs) play a vital role in oncogenicity. Nevertheless, the regulatory mechanisms and functions remain poorly understood, especially for lncRNAs and circRNAs. In this study, we simultaneously detected, for the first time, the expression profiles of the whole transcriptome, including miRNA, circRNA and lncRNA + mRNA, in five pairs of laryngeal squamous cell carcinoma (LSCC) and matched non-carcinoma tissues by microarrays. Five miRNAs, four circRNAs, three lncRNAs and five mRNAs that were dysregulated were selected to confirm the verification of the microarray data by quantitative real-time PCR (qRT-PCR) in 20 pairs of LSCC samples. We constructed LSCC-related competing endogenous RNA (ceRNA) networks of lncRNAs and circRNAs (circRNA or lncRNA-miRNA-mRNA) respectively. Functional annotation revealed the lncRNA-mediated ceRNA network were enriched for genes involved in the tumor-associated pathways. Hsa_circ_0033988 with the highest degree in the circRNA-mediated ceRNA network was associated with fatty acid degradation, which was responsible for the depletion of fat in tumor-associated cachexia. Finally, to clarify the ncRNA co-regulation mechanism, we constructed a circRNA-lncRNA co-regulated network by integrating the above two networks and identified 9 modules for further study. A subnetwork of module 2 with the most dysregulated microRNAs was extracted to establish the ncRNA-involved TGF-β-associated pathway. In conclusion, our findings provide a high-throughput microarray data of the coding and non-coding RNAs and establish the foundation for further functional research on the ceRNA regulatory mechanism of non-coding RNAs in LSCC.

Zhao R ，Li FQ ，Tian LL ，Shang DS ，Guo Y ，Zhang JR ，Liu M ... -  《-》

Whole transcriptome analysis of HCT-8 cells infected by Cryptosporidium parvum.

Cryptosporidium species are zoonotic protozoans that are important causes of diarrhoeal disease in both humans and animals. Non-coding RNAs (ncRNAs) play an important role in the innate immune defense against Cryptosporidium infection, but the underlying molecular mechanisms in the interaction between human ileocecal adenocarcinoma (HCT-8) cells and Cryptosporidium species have not been entirely revealed. The expression profiles of messenger RNAs (mRNAs), long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) in the early phase of infection of HCT-8 cells with Cryptosporidium parvum and at 3 and 12 h post infection were analyzed using the RNA-sequencing technique. The biological functions of differentially expressed RNAs (dif-RNAs) were discovered through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The targeting relationships between three ncRNAs and mRNAs were analyzed using bioinformatics methods, followed by building a competing endogenous RNA (ceRNA) regulatory network centered on miRNAs. After strictly filtering the raw data, our analysis revealed 393 dif-lncRNAs, 69 dif-miRNAs and 115 dif-mRNAs at 3 hpi, and 450 dif-lncRNAs, 129 dif-miRNAs, 117 dif-mRNAs and one dif-circRNA at 12 hpi. Of these, 94 dif-lncRNAs, 24 dif-miRNAs and 22 dif-mRNAs were detected at both post-infection time points. Eleven dif-lncRNAs, seven dif-miRNAs, eight dif-mRNAs and one circRNA were randomly selected and confirmed using the quantitative real-time PCR. Bioinformatics analyses showed that the dif-mRNAs were significantly enriched in nutritional absorption, metabolic processes and metabolism-related pathways, while the dif-lncRNAs were mainly involved in the pathways related to the infection and pathogenicity of C. parvum (e.g. tight junction protein) and immune-related pathways (e.g. cell adhesion molecules). In contrast, dif-miRNAs and dif-circRNA were significantly enriched in apoptosis and apoptosis-related pathways. Among the downregulated RNAs, the miRNAs has-miR-324-3p and hsa-miR-3127-5p appear to be crucial miRNAs which could negatively regulate circRNA, lncRNA and mRNA. The whole transcriptome profiles of HCT-8 cells infected with C. parvum were obtained in this study. The results of the GO and KEGG pathway analyses suggest significant roles for these dif-RNAs during the course of C. parvum infection. A ceRNA regulation network containing miRNA at its center was constructed for the first time, with hsa-miR-324-3p and hsa-miR-3127-5p being the crucial miRNAs. These findings provide novel insights into the responses of human intestinal epithelial cells to C. parvum infection.

Sun L ，Li J ，Xie F ，Wu S ，Shao T ，Li X ，Li J ，Jian F ，Zhang S ，Ning C ，Zhang L ，Wang R ... -  《Parasites & Vectors》

Hsa_circRNA_0059655 plays a role in salivary adenoid cystic carcinoma by functioning as a sponge of miR-338-3p.

Zhao F ，Chen CW ，Yang WW ，Xu LH ，Du ZH ，Ge XY ，Li SL ... -  《-》

Microarray Expression Profile and Functional Analysis of Circular RNAs in Osteosarcoma.

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents. However, the molecular mechanisms regulating osteosarcoma tumorigenesis and progression are still poorly understood. Circular RNAs (circRNAs) have been identified as microRNA sponges and are involved in many important biological processes. This study aims to investigate the global changes in the expression pattern of circRNAs in osteosarcoma and provide a comprehensive understanding of differentially expressed circRNAs. Microarray based circRNA expression was determined in osteosarcoma cell lines and compared with hFOB1.19, which was used as the normal control. We confirmed the microarray data by real time-qPCR in both osteosarcoma cell lines and tissues. The circRNA/microRNA/mRNA interaction network was predicted using bioinformatics. Gene Ontology analysis and 4 annotation tools for pathway analysis (KEGG, Biocarta, PANTHER and Reactome) were used to predict the functions of differentially expressed circRNAs. We revealed a number of differentially expressed circRNAs and 12 of them were confirmed, which suggests a potential role of circRNAs in OS. Among these differentially expressed circRNAs, hsa_circRNA_103801 was up-regulated in both osteosarcoma cell lines and tissues, while hsa_circRNA_104980 was down-regulated. The most likely potential target miRNAs for hsa_circRNA_103801 include hsa-miR-370-3p, hsa-miR-338-3p and hsa-miR-877-3p, while the most potential target miRNAs of hsa_circRNA_104980 consist of hsa-miR-1298-3p and hsa-miR-660-3p. Functional analysis found that hsa_circRNA_103801 was involved in pathways in cancer, such as the HIF-1, VEGF and angiogenesis pathway, the Rap1 signaling pathway and the PI3K-Akt signaling pathway, while hsa_circRNA_104980 was related to some pathways such as the tight junction pathway. This study has identified the comprehensive expression profile of circRNAs in osteosarcoma for the first time. And the ceRNA network prediction and bioinformatics functional analysis could provide a comprehensive understanding of hsa_circRNA_103801 and hsa_circRNA_104980, which may be involved in the initiation and progression of osteosarcoma. The present study indicates that circRNAs may play important roles in osteosarcoma and thus serve as biomarkers of osteosarcoma diagnosis and treatment.

Liu W ，Zhang J ，Zou C ，Xie X ，Wang Y ，Wang B ，Zhao Z ，Tu J ，Wang X ，Li H ，Shen J ，Yin J ... -  《-》