Changes of intracellular calcium, fatty acids and phospholipids during miltefosine-induced apoptosis monitored by fluorescence- and 13C NMR-spectroscopy.
The alkylphosphocholine Miltefosine (hexadecylphosphocholine, HePC) induces apoptosis in human epithelial KB cells, whereas no such effect can be observed in a resistant clone (KBres). Its mode of action is mediated via the cell membrane, whereas the mechanism is still widely unknown. The use of various spectroscopic methods (fluorescence spectroscopy with Fura-2/AM on viable cells, 13C NMR spectroscopy on lipid extracts) reveals osmotic and metabolic changes in HePC treated sensitive cells. Intracellular free Ca(2+)-concentration increased over 300% of control in apoptotic cells, whereas KBres cells showed only a minor increase and no morphological response typical for apoptosis. The Ca(2+)-influx was mediated via calcium channels in the cell membrane. The HePC-induced influx is prevented by Gd3+, which blocks those calcium channels. Cells, grown in Ca(2+)-free medium, showed no apoptotic behaviour after treatment with HePC. If apoptosis was induced, an increased fatty acid and subsequent phospholipid biosynthesis was observed. This effect seems to be a specific marker of apoptosis in KB cells.
Henke
J
J
Institut für Organische Chemie, Universität Bremen, Germany.
Engelmann
J
J
Kutscher
B
B
Nssner
G
G
Engel
J
J
Voegeli
R
R
Leibfritz
D
D
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005682:Gadolinium / Q000494:pharmacology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D010742:Phospholipid Ethers / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism*; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D005227:Fatty Acids; D010742:Phospholipid Ethers; D010743:Phospholipids; D010767:Phosphorylcholine; C026659:edelfosine; C039128:miltefosine; D005682:Gadolinium; D002118:Calcium