Expression of bcl-2 and bax in cells isolated from B-chronic lymphocytic leukemia patients at different stages of the disease

B-Chronic lymphocytic leukemia (B-CLL) is an example of a human malignancy caused by alterations in the pathways of programmed cell death. In this dis ease the anti-apoptotic protein, bcl-2, is overexpressed and may lead to th e prolonged survival of a malignant CLL clone. In the present study we exam ined the expression of bcl-2 and bar, which has an antagonistic role agains t the function of bcl-2, in cells from CLL patients at different stages of the disease, by immunoblot analysis. A direct association between the stage of the disease and the level of bcl-2 in the patients' cells was observed. At stages A and B, 33% and 29% of patients, respectively, expressed high l evels of bcl-2, as opposed to 80% of patients at stage C (p=0.019). Bax lev el was not significantly associated with the stage of the disease, although patients at stage C had higher levels of bar. In this study we found a tre nd of association between bcl-2 and bar levels. Analysis including all pati ents revealed that 65% of the patients who expressed high levels of bcl-2 h ad high levels of bar (p=0.058). Of patients in stage CI 45% expressed high levels of both bcl-2 and bar while 50% and 42% of patients at stages A and B had low levels of both proteins.