TGF-beta activity and expression of its receptors in B-cell chronic lymphocytic leukemia.
B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in Western countries and results from the accumulation of B-lymphocytes which are functionally abnormal and predominantly non-cycling in vivo. Consequently, it is important to understand why B-CLL cells accumulate in GO phase. Since TGF-beta is an important negative regulator of the immune system, a loss of responsiveness to this factor might provide a selective advantage to B-CLL cells. Here we review data on the role of TGF-beta in B-CLL. We show that the B-CLL cell response to TGF-beta signals is abnormal in vitro (inhibition of proliferation and induction of apoptosis). This lack of response of B-CLL cells to TGF-beta inhibition appears to be accompanied by a decrease or a loss of TGF-beta receptor expression.
Service de Médecine Interne et Laboratoire d'Investigation Clinique Henri Tagnon, Institut J. Bordet, Brussels, Belgium.
L
L
Lagneaux
A
A
Delforge
M
M
Bernier
P
P
Stryckmans
D
D
Bron
D017209:Apoptosis / Q000502:physiology; D019898:Autocrine Communication; D002455:Cell Division / Q000502:physiology; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta