A. Pituchnoworolska et al., TUMOR-NECROSIS-FACTOR-ALPHA (TNF-ALPHA) AND LEUKEMIC-CELLS - SECRETION AND RESPONSE, Clinical and laboratory haematology, 20(4), 1998, pp. 231-238
Leukaemic cells from various types (ALL-0, ALL-proB, ALL-common [cALL]
, ALL-T) of acute lymphoblastic leukaemia (ALL) and non-lymphoblastic
leukaemia (ANLL) were studied for their ability to produce tumour necr
osis factor alpha (TNF). The role of exogenous and endogenous TNF in p
roliferation in vitro of leukaemic cells was also assessed. Leukaemic
cells from different types of acute leukaemia were found to show major
differences in their ability to proliferate in vitro. High production
of TNF was observed mainly in ALL-T and ANLL but in ALL-T it was not
associated with the proliferation rate of leukaemic cells. In most ins
tances no bioactive TNF was detected. The variable response of leukaem
ic cells (inhibition or stimulation of proliferation) to exogenous hum
an recombinant (rTNF) was assessed. The role of endogenous TNF as a gr
owth factor or agent associated with resistance to exogenous TNF was e
xcluded as judged by a lack of effect of the TNF synthesis inhibitor p
entoxifylline (PTX) and of anti-TNF antibody and PTX/rTNF. There was n
o association of the effect of rTNF on proliferation of leukaemic cell
s with their immunophenotype, spontaneous release of TNF or proliferat
ion rate, Hence, this study does not provide evidence for the role of
TNF as a growth factor for leukaemic cells or for its role in the inhi
bition of proliferation of leukaemic cells.