Abstract
The expression of P53, Bcl-2, Bax, Bag-1, and Mcl-1 proteins in CD5/CD20-positive B-chronic lymphocytic leukemia (B-CLL) cells from 30 typical CLL patients was evaluated before and after 48 h of incubation with 10(-6) M fludarabine using multiparametric flow cytometric analysis. Protein expression was correlated with annexin V expression, Rai modified clinical staging, lymphocyte doubling time, and previous treatment. Our main goal was to determine the predictive value of these proteins in CLL cells in terms of disease evolution. Bcl-2 expression decreased from a median fluorescence index (MFI) of 331.71 +/- 42.2 to 245.81 +/- 52.2 (P < 0.001) after fludarabine treatment, but there was no difference between viable cells (331.57 +/- 44.6 MFI) and apoptotic cells (331.71 +/- 42.2 MFI) before incubation (P = 0.859). Bax expression was higher in viable cells (156.24 +/- 32.2 MFI) than in apoptotic cells (133.56 +/- 35.7 MFI) before incubation, probably reflecting defective apoptosis in CLL (P = 0.001). Mcl-1 expression was increased in fludarabine-resistant cells and seemed to be a remarkable protein for the inhibition of the apoptotic process in CLL (from 233.59 +/- 29.8 to 252.04 +/- 35.5; P = 0.033). After fludarabine treatment, Bag-1 expression was increased in fludarabine-resistant cells (from 425.55 +/- 39.3 to 447.49 +/- 34.5 MFI, P = 0.012), and interestingly, this higher expression occurred in patients who had a short lymphocyte doubling time (P = 0.022). Therefore, we could assume that Bag-1 expression in such situation might identify CLL patients who will need treatment earlier.
Highlights
B-cell chronic lymphocytic leukemia (BCLL) is a neoplasm that results in the accumulation of clonal CD5-positive B-cells with a low proliferation rate [1]
Bcl2 expression decreased from a median fluorescence index (MFI) of 331.71 ± 42.2 to 245.81 ± 52.2 (P < 0.001) after fludarabine treatment, but there was no difference between viable cells (331.57 ± 44.6 MFI) and apoptotic cells (331.71 ± 42.2 MFI) before incubation (P = 0.859)
Bag-1 expression was increased in fludarabine-resistant cells, and interestingly, this higher expression occurred in patients who had a short lymphocyte doubling time (P = 0.022)
Summary
B-cell chronic lymphocytic leukemia (BCLL) is a neoplasm that results in the accumulation of clonal CD5-positive B-cells with a low proliferation rate [1]. Group I Bcl-2 proteins can form heterodimers with group II and prevent the occurrence of programmed cell death [5]. Bag was first cloned from mouse cells as a novel protein which interacts with Bcl-2 and Bcl-XL, enhancing the ability of Bcl-2 to prevent apoptosis. The exact mechanism of apoptosis induction by F-ara-A in proliferative and quiescent cells has not been completely established; some data suggest that purine nucleoside analogs may function as activators for d-ATP-dependent caspase pathways [9,10]. The expression of P53, Bcl-2, Bax, Bag-1, and Mcl-1 proteins in CD5-positive B-CLL cells in 30 typical CLL patients on two different occasions, i.e., before and after 48 h of fludarabine incubation. Our main goal was to determine the value of these apoptotic proteins in CLL cells in order to predict the evolution of the disease
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
