The inhibitory effects of gga-miR-199-3p, gga-miR-140-3p, and gga-miR-221-5p in Marek's disease tumorigenesis.

Marek's disease (MD) is lymphoproliferative neoplastic disease in chickens, which is caused by Marek's disease virus (MDV). Our previous study profiled microRNA (miRNA) transcriptome in MD lymphoma, and found that gga-miR-199-3p, gga-miR-140-3p, and gga-miR-221-5p were down-regulated in MD lymphoma. In this study, we further investigated their differential expression between MDV-infected spleens and noninfected spleens at 4, 7, 14, 21, and 28 d postinfection (dpi) to elucidate whether deregulation of them was specific to late tumor transformation phase or not. The results showed that gga-miR-199-3p was down-regulated at 14 and 28 dpi, and the expression of gga-miR-140-3p was decreased at 14 dpi, which indicated that deregulation of these miRNAs appeared since early stage of MD tumor transformation. Additionally, the inhibitory effects of gga-miR-199-3p, gga-miR-140-3p, and gga-miR-221-5p on MDV-transformed lymphoid cell line (MSB1) cells proliferation were observed, which suggested that these miRNAs acted as MD tumor suppressors. Their aberrant expression at early tumor transformation phase and suppressive role in cell proliferation indicated that they were involved in MD lymphoma transformation, and might play crucial roles in MD tumorigenesis.

Lian L ，Zhang D ，Wang Q ，Yang N ，Qu L ... -  《-》

Chicken gga-miR-181a targets MYBL1 and shows an inhibitory effect on proliferation of Marek's disease virus-transformed lymphoid cell line.

Marek's disease (MD), caused by Marek's disease virus (MDV), is a lymphoproliferative neoplastic disease of chickens and is characterized by MD lymphoma in multiple visceral organs of chicken. It causes great damage to poultry health. Recently, miRNA has been reported to be involved in Marek's disease lymphomagenesis. Our previous study showed that gga-miR-181a was downregulated in MDV-induced lymphoma, and its target gene, v-myb myeloblastosis viral oncogene homolog-like 1 (MYBL1), was predicted. In this study, the interaction between gga-miR-181a and MYBL1 was further verified by detecting protein expression levels of MYBL1 after transfecting miR-181a mimic into MD lymphoma cell line, MSB1. The result showed that protein level of MYBL1 was lower in gga-miR-181a mimic transfecting group than that in the negative control group at 96 h post transfection, which indicated that MYBL1 was a target gene of gga-miR-181a. Additionally, we found that the expression of MYBL1 was higher in MDV-infected samples than that in non-infected controls, which agreed with the proposition that miRNA showed a negatively correlated expression pattern with its target gene. We observed the inhibitory effect of gga-miR-181a on MSB1 cell proliferation. Collectively, the aberrant expression of gga-miR-181a and MYBL1 in MD lymphoma suggested that they might be involved in MD tumor transformation and played important roles.

Lian L ，Li X ，Zhao C ，Han B ，Qu L ，Song J ，Liu C ，Yang N ... -  《-》

gga-miR-26a targets NEK6 and suppresses Marek's disease lymphoma cell proliferation.

Li X ，Lian L ，Zhang D ，Qu L ，Yang N ... -  《-》

A systematic analysis of miRNA transcriptome in Marek's disease virus-induced lymphoma reveals novel and differentially expressed miRNAs.

Lian L ，Qu L ，Chen Y ，Lamont SJ ，Yang N ... -  《PLoS One》

Chicken gga-miR-103-3p Targets CCNE1 and TFDP2 and Inhibits MDCC-MSB1 Cell Migration.

Marek's disease (MD) is a highly contagious viral neoplastic disease caused by Marek's disease virus (MDV), which can lead to huge economic losses in the poultry industry. Recently, microRNAs (miRNAs) have been found in various cancers and tumors. In recent years, 994 mature miRNAs have been identified through deep sequencing in chickens, but only a few miRNAs have been investigated further in terms of their function. Previously, gga-miR-103-3p was found downregulated in MDV-infected samples by using Solexa deep sequencing. In this study, we further verified the expression of gga-miR-103-3p among MDV-infected spleen, MD lymphoma from liver, noninfected spleen, and noninfected liver, by qPCR. The results showed that the expression of gga-miR-103-3p was decreased in MDV-infected tissues, which was consistent with our previous study. Furthermore, two target genes of gga-miR-103-3p, cyclin E1 (CCNE1) and transcription factor Dp-2 (E2F dimerization partner 2) (TFDP2), were predicted and validated by luciferase reporter assay, qPCR, and western blot analysis. The results suggested that CCNE1 and TFDP2 are direct targets of gga-miR-103-3p in chickens. Subsequent cell proliferation and migration assay showed that gga-miR-103-3p suppressed MDCC-MSB1 migration, but did not obviously modulate MDCC-MSB1 cell proliferation. In conclusion, gga-miR-103-3p targets the CCNE1 and TFDP2 genes, and suppresses cell migration, which indicates that it might play an important role in MD tumor transformation.

Han B ，Lian L ，Li X ，Zhao C ，Qu L ，Liu C ，Song J ，Yang N ... -  《G3-Genes Genomes Genetics》