Avian leukosis virus subgroup J promotes cell proliferation and cell cycle progression through miR-221 by targeting...

Area of Science:

• Oncology
• Virology
• Molecular Biology

Background:

• Avian leukosis virus subgroup J (ALV-J) is a potent oncogenic retrovirus causing proliferative diseases in chickens.
• MicroRNAs regulate gene expression post-transcriptionally and are implicated in tumor development.
• Previous studies indicated miR-221 upregulation in ALV-J-induced tumors.

Purpose of the Study:

• To investigate the functional role of miR-221 in ALV-J-induced tumorigenesis.
• To identify and validate targets of miR-221 involved in ALV-J pathogenesis.
• To elucidate the molecular mechanisms by which miR-221 contributes to ALV-J-driven cancer.

Main Methods:

• Target validation assays to confirm CDKN1B as a miR-221 target.
• Analysis of CDKN1B expression in ALV-J infected cells.
• Cell proliferation assays using ALV-J infected DF-1 cells.
• Cell cycle analysis to assess G1/S transition.
• Pathway analysis of the CDKN1B-CDK2/CDK6 signaling axis.

Main Results:

• CDKN1B was validated as a direct target of miR-221 and was found to be downregulated during ALV-J infection.
• ALV-J infection led to derepression of the G1/S cell cycle transition and overproliferation of DF-1 cells.
• High miR-221 expression and subsequent CDKN1B downregulation were essential for ALV-J-induced cell overproliferation.
• ALV-J infection promoted DF-1 cell overproliferation through the CDKN1B-CDK2/CDK6 pathway.

Conclusions:

• miR-221 plays a critical role in promoting the aggressive growth of DF-1 cells induced by ALV-J.
• The findings enhance understanding of the molecular mechanisms underlying ALV-J infection and tumorigenesis.
• Targeting the miR-221/CDKN1B axis could offer potential therapeutic strategies against ALV-J-associated cancers.