Studies on some lipogenic enzymes of cultured myeloid leukemic cells
M Okuma, Y Ichikawa, S Yamashita, K Kitajima and S Numa
The microsomal fraction of M1 cells (an established cell line of myeloid
leukemia) was capable of catalyzing acylation of sn-glycerol 3- phosphate
by long-chain fatty acyl-CoA thioesters. The principal lipid product formed
was identified as phosphatidic acid. Palmityl-CoA, stearyl-CoA, and
oleyl-CoA were more effective acyl donors than linoleyl-CoA and
arachidonyl-CoA. M1 cells and macrophages differentiated from them
exhibited similar levels of sn-glycerol 3- phosphate-acylating activity,
which were approximately one-half that in mouse liver and approximately
four times that in peritoneal macrophages. The levels of acetyl-CoA
carboxylase activity in M1 cells and macrophages differentiated from them
were not significantly different from each other and were comparable to
those in mouse liver, whereas no activity was detected in peritoneal
macrophages. These results indicated that differentiation of the myeloid
leukemic cells, which results in loss of leukemogenicity and mitotic
activity, is not associated with changes in the activities of these
lipogenic enzymes, although the cultured cells exhibited remarkably higher
activities than freshly harvested peritoneal macrophages. Furthermore, the
present study supports the view that the glycerophosphate pathway makes an
essential contribution to the de novo synthesis of phospholipids in M1
cells, as well as in both types of macrophages.
Volume 47,
Issue 3,
pp. 439-446,
03/01/1976
Copyright © 1976 by The American Society of Hematology
