Comprehensive analysis of long noncoding RNA and mRNA in five colorectal cancer tissues and five normal tissues

The present study investigated the role of abnormally expressed mRNA and long noncoding RNA (lncRNA) in the development of colorectal cancer (CRC). We used lncRNA sequencing to analyze the transcriptome (mRNA and lncRNA) of five pairs of CRC tissues and adjacent normal tissues. The total expression of mRNAs and lncRNAs in each sample was determined using the R package and the gene expression was calculated using normalized FPKM. The structural features and expression of all detected lncRNAs were compared with those of mRNAs. Differentially expressed mRNAs were selected to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The functional analysis of differentially expressed lncRNAs was performed by analyzing the GO and KEGG enrichment of predicted cis-regulated target genes. A total of 18.2 x 10(8) reads were obtained by sequencing, in which the clean reads reached >= 94.67%, with a total of 245.2 G bases. The number of mRNAs and lncRNAs differentially expressed in CRC tissues and normal tissues were 113 and 6, respectively. Further predictive analysis of target genes of lncRNAs revealed that six lncRNA genes had potential cis-regulatory effects on 13 differentially expressed mRNA genes and co-expressed with 53 mRNAs. Up-regulated CTD-2256P15.4 and RP11-229P13.23 were the most important lncRNAs in these CRC tissues and involved in cell proliferation and pathway in cancer. In conclusion, our study provides evidence regarding the mRNA and lncRNA transcription in CRC tissues, as well as new insights into the lncRNAs and mRNAs involved in the development of CRC.