PPP2R1B gene in chronic lymphocytic leukemias and mantle cell lymphomas.

Deletion of chromosome bands 11q22-q23 is one of the most common structural chromosome alterations in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). The PPP2R1B gene is located very close to the minimal common deletion region of 11q22-q23 in CLL and MCL. Recently, the PPP2R1B gene was found to be mutated in human lung and colon cancers. To evaluate the role of the PPP2R1B gene in the pathogenesis of CLL and MCL, we performed RT-PCR analysis and cDNA sequencing on 10 CLL RNA samples and SSCP analysis on 26 CLL and 37 MCL genomic DNA samples. A deletion of exon 3 was found in one CLL sample. No mutation was detected in the SSCP analysis. To exclude the possibility of large genomic deletions we performed Southern blotting analysis. One MCL sample showed abnormal bands. Our results do not suggest that the PPP2R1B gene has a major pathogenic role in CLL and MCL.