[Shape change in human megakaryoblastic leukemia cells, MEG-01].
We investigated the intracellular processes of the shape change in the human megakaryoblastic leukemia cell, MEG-01, by platelet agonists. Thrombin induced the formation of many pseudopods. This shape change was also induced by TPA and A23187, but not by ADP, collagen, or epinephrine. Electron microscopy and FITC-labeled phalloidin staining revealed thick submembranous microfilament bundles in the pseudopods of the shape-changed cells induced by thrombin. Shape change was inhibited by cytochalasin B. Protein kinase C (RKC) inhibitor, H-7, markedly inhibited thrombin-induced shape change, while the myosin light chain kinase (MLCK) inhibitor, ML-9 did not. These results suggest that thrombin-induced reorganization of microfilaments and shape change of MEG-01 cells are mediated by PKC but not by MLCK.
Goto
S
S
First Department of Internal Medicine, Nagoya University School of Medicine.
Kobayashi
M
M
Hidaka
H
H
Saito
H
H
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000001:Calcimycin / Q000494:pharmacology; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D007947:Leukemia, Megakaryoblastic, Acute / Q000473:pathology*; D008533:Megakaryocytes / Q000187:drug effects* / Q000648:ultrastructure; D008854:Microscopy, Electron; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010959:Tissue Plasminogen Activator / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D007546:Isoquinolines; D010879:Piperazines; D000001:Calcimycin; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D013917:Thrombin; D010959:Tissue Plasminogen Activator