Stimulation of leukemic myelopoiesis by P30-35 CAMAL, an inhibitor of normal myelopoiesis.
CAMAL (common antigen in myelogenous acute leukemia) is an antigenic preparation isolated in this laboratory from the bone marrow or peripheral blood cells of persons with myeloid leukemias and shown in an immunoperoxidase slide test to be diagnostic of these leukemias. CAMAL has been shown to be inhibitory to myelopoiesis by normal progenitor cells in vitro. This activity is associated with material which was further purified from CAMAL preparations, and which migrates at 30-35 kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). We now report that material from CAMAL preparations highly enriched for this 30-35 kDa material is stimulatory to in vitro colony formation by progenitor cells from patients with chronic myelogenous leukemia (CML). This stimulatory effect on CML colony formation was observed to be consistent. Colony formation was stimulated in a biphasic fashion; enhancement was seen at low (1 to 10 ng/ml) and high (100 to 200 ng/ml) concentrations of P30-35 CAMAL, but enhancement was reduced or absent at an intermediate concentration of P30-35 CAMAL (10 to 70 ng/ml), and was not observed at P30-35 CAMAL levels above 200 ng/ml, or below 1 ng/ml. The colony types in cultures of CML clinical specimens targetted for enhancement by P30-35 CAMAL were identified. At low concentrations of P30-35 CAMAL primitive colonies were increased, whereas at high concentrations of P30-35 CAMAL, an increase in all colony types was observed. In addition, an increase in the size of some colonies within P30-35 CAMAL-treated cultures was frequently observed. Colony formation by two cell lines derived from the leucocytes of a patient with CML was enhanced by treatment with P30-35 CAMAL in a manner similar to the stimulation observed using primary cells from CML clinical specimens.
Department of Microbiology, University of British Columbia, Vancouver, Canada.
H A
HA
Leitch
N
N
Buskard
J G
JG
Levy
D015214:Antigens, Differentiation, Myelomonocytic / Q000494:pharmacology*; D001853:Bone Marrow / Q000473:pathology*; D006410:Hematopoiesis; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D008970:Molecular Weight; D014411:Neoplastic Stem Cells / Q000473:pathology*; D014410:Tumor Stem Cell Assay
D015214:Antigens, Differentiation, Myelomonocytic; C061798:common myelogenous leukemia-associated antigen