Chicken gga-miR-130a targets HOXA3 and MDFIC and inhibits Marek's disease lymphoma cell proliferation and migration

Marek's disease (MD) is an infectious disease of chickens caused by MD virus (MDV), which is a herpesvirus that initiates tumor formation. Studies have indicated that microRNAs (miRNAs) are linked with the development of cancers or tumors. Previously, gga-miR-130a was discovered downregulated in MDV-infected tissues. Here, we aimed to explore the further function of gga-miR-130a in MD. The expression of gga-miR-130a in MDV-infected and uninfected spleens was detected by quantitative real-time PCR (qRT-PCR). Subsequently, proliferation and migration assays of MDV-transformed lymphoid cells (MSB1) were carried out by transfecting gga-miR-130a. The target genes of gga-miR-130a were predicted using TargetScan and miRDB and clustered through Gene Ontology analysis. The target genes were validated by western blot, qRT-PCR, and a dual luciferase reporter assay. Our results show that the expression of gga-miR-130a was reduced in MDV-infected spleens. Gga-miR-130a showed an inhibitory effect on MSB1 cell proliferation and migration. Two target genes, homeobox A3 (HOXA3) and MyoD family inhibitor domain containing (MDFIC), were predicted and clustered to cell proliferation. Results indicate that gga-miR-130a regulates HOXA3 and MDFIC at the protein level but not at the mRNA level. Moreover, the gga-miR-130a binding sites of two target genes have been confirmed. We conclude that gga-miR-130a can arrest MSB1 cell proliferation and migration, and target HOXA3 and MDFIC, which are both involved in the regulation of cell proliferation. Collectively, gga-miR-130a plays a critical role in the tumorigenesis associated with chicken MD.