Comperative Transcriptomics Study Of The HepG2 Stimulated By UC-MSCs Supernate

Mesenchymal stem cells (MSCs) are adult stem cells derived from the mesoderm. Their low immunogenicity and availability from many different adult tissues, are the utmost characteristics of MSCs that make them a great resource for therapy, such as cardiovascular disease, neurologic disease, immunodeficiency disease and cancer. Numerous lines of evidence demonstrated that MSCs can be recruited by tumors and have impact on tumor microenvironment during tumorigenesis and tumor development. MSCs secrete various cytokines and growth factors, which affect the cell proliferation, migration and angiogenesis of the tumor.Based on our previous study, umbilical cords derived MSCs supernate has an inhibitory effect on the proliferation of HepG2. To explore the molecular mechanisms underlying such phenomenon, 5 stages of the UC-MSCs supernate stimulated HepG2 were sequenced using short reads sequencing technology to obtain the transcriptom information of the cell lines. As a result,47.67, 47.68,47.74,47.69 and 47.53 million clean reads were obtained. Clean reads were mapped to a reference sequences, the genome coverage of the samples were over 84%, and the proportions of genes with certain coverage were over 78%. The number of differential expressed genes (DEGs) was over 16,000, and also 50,000 of alternative splicing events were found. Over 50,000 SNP loci were identified. We also recognized 20 gene fusion events. DEGs statistics showed that as the stimulation time prolonged, the number of DEGs was increased.Large amounts of annotated information were obtained by enrichment analysis of Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) of the identified DEGs. After 24 hours,117 DEGs were enriched in GO terms of cell proliferation.59 DEGs were enriched in MAPK pathways, and 69 DEGs were enriched in pathways in cancer, etc. According to the gene expression patterns, the possible roles for UC-MSCs supernate in inhibitory effect on the proliferation of HepG2 were discussed. The expression patterns of the DEGs detected by qRT-PCR were highly consistent with the RNA-seq data.