Proviral ALV-LTR Sequence Is Essential for Continued Proliferation of the ALV-Transformed B Cell Line.

Avian leukosis virus (ALV) induces B-cell lymphomas and other malignancies in chickens through insertional activation of oncogenes, and activation has been commonly identified in ALV-induced tumors. Using ALV-transformed B-lymphoma-derived HP45 cell line, we applied in situ CRISPR-Cas9 editing of integrated proviral long terminal repeat (LTR) to examine the effects on gene expression and cell proliferation. Targeted deletion of LTR resulted in significant reduction in expression of a number of LTR-regulated genes including .

Multifunctional miR-155 Pathway in Avian Oncogenic Virus-Induced Neoplastic Diseases.

MicroRNAs (miRNAs) are small noncoding RNAs that fine-tune the responses of the cell by modulating the cell transcriptome and gene expression. MicroRNA 155 (miR-155) is a conserved multifunctional miRNA involved in multiple roles including the modulation of the immune responses. When deregulated, miR-155 can also contribute to cancer as has been demonstrated in several human malignancies such as diffuse large B cell lymphoma, chronic lymphocytic leukemia, as well as in Epstein⁻Barr virus (EBV)-induced B cell transformation.