COMPARISON OF THE EFFECTS OF ACSDKP, THYMOSIN BETA-4, MACROPHAGE INFLAMMATORY PROTEIN 1-ALPHA AND TRANSFORMING-GROWTH-FACTOR-BETA ON HUMAN LEUKEMIC-CELLS

We have compared the effects of AcSDKP, Thymosin beta 4 (T beta 4), MI P1 alpha and TGF beta on acute myeloid leukemia (AML) and B-lineage ac ute lymphoid leukemia (B-ALL) cells using liquid cultures in the prese nce of GM-CSF, IL-3 and SCF for AML cells and IL-3 and IL-7 for ALL ce lls. Each molecule was added daily and cell proliferation was evaluate d on day 3 by thymidine incorporation. Whereas TGF beta was found inhi bitory in all the AML and B-ALL cases studied, MIP1 alpha was inhibito ry in 6/12 AML cases and had no effect on B-ALL cells. AcSDKP and T be ta 4 showed an inhibitory effect in a few cases but only at high doses which were inactive on normal cells. Thus, our study not only confirm s the effect of TGF beta, MIP1 alpha and AcSDKP on AML cells but also provides new data concerning their effect on B-ALL and the possible in hibitory effect of AcSDKP at high doses. Furthermore, we show for the first time the effect of T beta 4 on leukemic cells. Altogether, our d ata indicate differences of sensitivity of leukemic cells to negative regulators, some leukemias being inhibited by one or several of these molecules whereas others were unresponsive to all used. The clinical r elevance of these observations still remains to be determined.