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-2α and β isoforms and the pro-apoptotic Baxα and β 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-2α and Baxα are expressed at higher levels than their β-isoforms in CLL and HC. Bcl-2α, Bcl-2β and Baxβ expression is increased in CLL while Bax-α is expressed at similar levels to HC. The Bcl-2α/Bcl-2β ratio is similar in CLL and HC. The Bcl-2α/Baxα ratio is increased in CLL when compared with HC.

Conclusion: Bcl-2α and Baxα appear to be the dominant anti- and pro-apoptotic isoforms in CLL. The Bcl-2α/Baxα ratio is increased in CLL while the Bcl-2α/Bcl-2β ratio is similar to HC.