Identification and differential expression of microRNAs in Madin-Darby canine kidney cells with high and low...

Madin-Darby canine kidney (MDCK) cells are widely used for vaccine production, however, the safety of MDCK cells needs to be considered seriously because of high tumorigenicity. Micro RNAs (miRNAs) that are involved in the tumorigenicity of MDCK cells have been never been reported.

To reveal the role of miRNA in the tumorigenic phenotype of MDCK cell line.

The miRNA expression profiles of two monoclonal MDCK cells (M09CL and M35CL) with low tumorigenicity and one MDCK cell line (M73P) with high tumorigenicity were characterized and investigated by using small RNA-seq technology.

A total of 5 known miRNAs and 5 novel miRNAs were highly expressed in M73P. In addition, 4 known miRNAs and 4 novel miRNAs were highly expressed in M09CL and M35CL. The target genes of the differentially expressed miRNAs were significantly enriched in several biological processes, and the majority of these genes were involved in pathways in cancer and the MAPK signaling pathway. Through interaction analysis, 4 up-regulated miRNAs (cfa-miR-452, cfa-miR-8826, cfa-miR-224, and cfa-miR-2387) and their crucial target genes related to the tumor regulation network were identified. Results indicated these 4 miRNAs might play crucial roles in the tumorigenesis of MDCK cells.

Our findings, which were based on the functional prediction of miRNAs and target genes, suggested that miRNAs might influence the tumorigenicity of MDCK cells by regulating target genes. Moreover, the results provided important data for understanding the miRNA-mediated regulatory networks that control the tumorigenicities of MDCK cells.