Oxidative stress accelerates spontaneous apoptosis of B-chronic lymphocytic leukemia lymphocytes.
OBJECTIVE
B-chronic lymphocytic leukemia (B-CLL) is characterized by the progressive accumulation of small immature B lymphocytes which do not undergo apoptosis due to an underlying defect. One potential mechanism of defective apoptosis could be irregular oxidative stress. The goal of our investigation was to determine in vitro production of oxidative stress markers by lymphocytes of B-CLL patients.


METHODS
30 untreated stage A B-CLL patients, as well as 20 stage B and C patients and 30 healthy volunteers as a control group were examined. Nitric oxide (NO), superoxide anion, hydrogen peroxide and malondialdehyde (MDA) were measured by spectrophotometry in supernatants of lymphocytes cultures of all 3 investigational groups. The method applied for detecting apoptosis was fluorescence microscopic analysis using acridine orange/ethidium bromide (AO/EB) double staining.


RESULTS
In vitro lymphocyte production of superoxide anion, hydrogen peroxide and MDA was increased in B-CLL patients, while there were no statistical significantly differences of NO production among the tested groups. Compared with the spontaneous apoptosis observed in control subjects lymphocytes, B-CLL lymphocytes showed increased percentages of apoptotic cells after incubation for 24 h. Disease progression was not followed with significant differences in spontaneous apoptosis of B-CLL lymphocytes.


CONCLUSIONS
This intensive oxidative stress markers production in cultures of B-CLL lymphocytes could be one of the potential mechanisms in the pathogenesis of abnormal apoptosis.
Djurdjevic
P
P
Department of Pathophysiology, Faculty of Medicine, University of Kragujevac, Kragujevac, Serbia. zekapeka@ptt.yu
Zelen
I
I
Ristic
P
P
Jovanovic
I
I
Jakovljevic
V
V
Baskic
D
D
Popovic
S
S
Arsenijevic
N
N
D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D018450:Disease Progression; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism* / Q000473:pathology*; D008214:Lymphocytes / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D013481:Superoxides / Q000378:metabolism
D013481:Superoxides; D009569:Nitric Oxide; D008315:Malondialdehyde; D006861:Hydrogen Peroxide