Differential expression of the Bcl-2 and Bax isoforms in CD19 positive B-lymphocytes isolated from patients diagnosed with chronic lymphocytic leukaemia

Aim: To examine the relative gene expression levels of the anti-apoptotic Bcl-2 alpha and beta isoforms and the pro-apoptotic Bax alpha and beta isoforms in patients with chronic lymphocytic leukaemia (CLL) and healthy controls (HC). Methods: Peripheral blood was obtained from 36 patients diagnosed with CLL and 10 HC. CD19(+) B-lymphocytes were isolated using an antibody coupled magnetic bead isolation system; from these cells the total RNA was isolated and purified. The relative levels of gene expression were examined by quantitative real-time polymerase chain reaction (qReTi-PCR) using primers specific for each isoform. Results: Bcl-2 alpha and Bax alpha are expressed at higher levels than their beta-isoforms in CLL and HC. Bcl-2 alpha, Bcl-2 beta and Bax beta expression is increased in CLL while Bax-alpha is expressed at similar levels to HC. The Bcl-2 alpha/Bcl-2 beta ratio is similar in CLL and HC. The Bcl-2 alpha/Bax alpha ratio is increased in CLL when compared with HC. Conclusion: Bcl-2 alpha and Bax alpha appear to be the dominant anti- and pro-apoptotic isoforms in CLL. The Bcl-2 alpha/Bax alpha ratio is increased in CLL while the Bcl-2 alpha/Bcl-2 beta ratio is similar to HC.