Recurrent reciprocal RNA chimera involving YPEL5 and PPP1CB in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in adults in the Western hemisphere. Tumor-specific chromosomal translocations, characteristic findings in several human malignancies that directly lead to malignant transformation, have not been identified in CLL. Using paired-end transcriptome sequencing, we identified recurrent and reciprocal RNA chimeras involving yippee like 5 (YPEL5) and serine/threonine-protein phosphatase PP1-beta-catalytic subunit (PPP1CB) in CLL. Two of seven index cases (28%) harbored the reciprocal RNA chimeras in our initial screening. Using quantitative real-time PCR (q real-time PCR), YPEL5/PPP1CB and PPP1CB/YPEL5 fusion transcripts were detected in 97 of 103 CLL samples (95%) but not in paired normal samples, benign lymphocytes, or various unrelated cancers. Whole-genome sequencing and Southern blotting demonstrated no evidence for a genomic fusion between YPEL5 and PPP1CB. YPEL5/PPP1CB chimera, when introduced into mammalian cells, expressed a truncated PPP1CB protein that demonstrated diminished phosphatase activity. PPP1CB silencing resulted in enhanced proliferation and colony formation of MEC1 and JVM3 cells, implying a role in the pathogenesis of mature B-cell leukemia. These studies uncover a potential role for recurrent RNA chimeras involving phosphatases in the pathogenesis of a common form of leukemia.

Citation

Thirunavukkarasu Velusamy, Nallasivam Palanisamy, Shanker Kalyana-Sundaram, Anagh Anant Sahasrabuddhe, Christopher A Maher, Daniel R Robinson, David W Bahler, Timothy T Cornell, Thomas E Wilson, Megan S Lim, Arul M Chinnaiyan, Kojo S J Elenitoba-Johnson. Recurrent reciprocal RNA chimera involving YPEL5 and PPP1CB in chronic lymphocytic leukemia. Proceedings of the National Academy of Sciences of the United States of America. 2013 Feb 19;110(8):3035-40

Mesh Tags

Substances

PMID: 23382248

search → result