Expression of dysregulated miRNA in vivo in DF-1 cells during the course of subgroup J avian leukosis virus infection.

Aberrant expression of microRNAs (miRNAs) is known to be involved in cancer progression caused by subgroup J avian leukosis virus (ALV-J) in liver tissues. To advance our understanding of the related pathological mechanisms and virus-host interactions, seven previously reported miRNAs were selected for a comparative analysis of miRNA expression between infected and uninfected DF-1 cells, including six miRNAs related to tumorigenesis (let-7b/7i, miR-221/222, miR-125b, miR-375 and miR-2127. The results showed that six of the seven miRNAs except gga-miR-375 were upregulated in cells infected with NX0101 (caused myeloma (ML)) and GD1109 (caused hemangioma (HE)) at 1 h post infection. On day 2 post-infection, all seven miRNAs were upregulated in infected DF-1 cells. On day 6 post-infection, gga-let-7b, gga-miR-125b, and gga-miR-375 were downregulated whereas gga-miR-221 and gga-miR-222 were upregulated in DF-1 cells infected with the two ALV-J strains of different phenotypes. However, expression of gga-let-7i was reduced in DF-1 cells infected with NX0101 and was increased in those infected with GD1109; gga-miR-2127 expression showed no significant difference between infected and uninfected cells. This study is the first to report the changes in the miRNA expression levels in DF-1 cells during the course of ALV-J infection, and suggests a relationship between its pathological mechanisms and miRNAs.