Phorbol ester induces abnormal chronic lymphocytic leukemia cells to
express features of hairy cell leukemia
F Caligaris-Cappio, G Pizzolo, M Chilosi, L Bergui, G Semenzato, L Tesio, L Morittu, F Malavasi, M Gobbi and R Schwarting
We have investigated the relationship between chronic lymphocytic leukemia
(CLL), hairy cell leukemia (HCL), and different normal B cell subsets:
Mrbc+, T1+ and slgM+ tonsil cells; germinal center; mantle zone; and
peripheral blood B lymphocytes. Both malignant and normal cells were
incubated in vitro with the phorbol ester 12-O-tetradecanoyl-
phorbol-13-acetate (TPA) for 72 hours and the morphology, cytochemical
profile, and surface markers were evaluated. The results show that CLL
cells TPA-induced become indistinguishable from HCL by four independent
criteria: the morphology; the cytoplasmic tartrate resistant acid
phosphatase (TRAP) enzyme activity; the membrane positivity with anti- Leu
M5 (SHCL3); and anti-Tac monoclonal antibodies which, in the uninduced
state, react only with HCL. The features of TRAP and Tac positivity are
also expressed (though in variable degree) by different normal B cell
populations activated with TPA or pokeweed mitogen (PWM). It is concluded
that HCL might represent an aberrantly activated variant of CLL (or of a
CLL-related disorder).
Volume 66,
Issue 5,
pp. 1035-1042,
11/01/1985
Copyright © 1985 by The American Society of Hematology