Identification of aberrantly expressed circRNAs in subgroup J avian leucosis virus induced tumor livers by RNA sequencing

Authors: ZHANG, X - South China Agricultural University; YAN, Y - South China Agricultural University; LEI, X - South China Agricultural University; LI, A - South China Agricultural University; Zhang, Huanmin; DAI, Z - South China Agricultural University; LI, X - South China Agricultural University; CHEN, W - South China Agricultural University; LIN, W - South China Agricultural University; CHEN, F - South China Agricultural University; MA, J - South China Agricultural University; XIE, Q - South China Agricultural University

Submitted to: Oncotarget
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2017
Publication Date: N/A
Citation: N/A
DOI: https://doi.org/10.18632/oncotarget.24181

Interpretive Summary: Subgroup J Avian Leucosis virus (ALV-J) is an oncogenic retrovirus that causes severe production and reproduction issues in poultry. The mechanism of pathogenesis in ALV-J infection induction of tumor formation, however, is yet to be elucidated. A specific class of small non-coding RNAs, commonly known as circRNAs, in recent years has been illustrated in association with cancer development in human. This study was designed to explore the potential roles that circRNAs may play in ALV-J induced pathogenicity. A total of 2,822 circRNAs were detected with expressional differences between liver tumors of chickens challenged with ALV-J and normal liver samples. Another class of small RNAs known as microRNAs was also selectively examined, which targeted 24 of the differentially expressed circRNAs. Data from this study suggested that altered metabolism may play a key role in ALV-J-induced tumorigenesis. Future studies on epigenetics are warranted to further elucidate the pathogenicity mechanism in association with ALV-J infection in chicken in order to keep improving the basic understanding and the preventative control measures of this disease in poultry.

Technical Abstract: ALV-J (subgroup J avian leucosis virus) is a kind of oncogenic exogenous retrovirus and diseases associated with ALV-J have caused severe reproduction problems in the poultry industry worldwide. However, the pathogenesis of ALV-J-induced tumor formation is still unclear. In recent years, circRNAs are validated to be related to cancer, which prompts us to explore whether aberrant expression of circRNAs exists in ALV-J-infected tumor samples. In this study, a total of 2,822 differentially expressed circRNAs were detected by RNA sequencing between the tumor livers of ALV-J-susceptible chickens (n = 3) and the normal liver samples of ALV-J-resistant chickens (n = 3), among which 2,808 circRNAs in the tumor liver samples were detected as upregulated compared to those in the normal liver samples. In general, circRNAs are considered as miRNA sponge. Therefore, we predicted top 5 miRNA targets for 24 of the upregulated circRNAs identified in the ALV-J-induced liver tumors. CircRNA-miRNA-mRNA regulatory axes were also constructed to illustrate the interaction relationship among them. Furthermore, Gene Ontology and KEGG pathway analyses were performed for miRNA target genes, and the result of which implied that metabolism plays a key role in circRNA expression alterations in ALV-J-induced liver tumors. In summary, we identified circRNAs that were involved in ALV-J-induced tumor formation in chickens. However, the pathogenicity mechanism still needs to be further explored.