Metabolism and effect of platelet-activating factor on the growth of human myeloma cell lines.
In this study we have investigated the presence of PAF receptor (PAF-R) on 5 myeloma cell lines (U266, L363, IM9, OPM2 and XG1), their metabolism of PAF and lyso PAF, and the effect of PAF on their growth. All myeloma cell lines express a PAF acetylhydrolase activity and metabolize [3H]PAF and [3H]lyso PAF in 1-alkyl-2-acyl analogue of phosphatidylcholine. Polymerase chain reaction on reverse transcript (RT-PCR) experiments indicate that OPM2, U266, IM9, XG1 and L363 cells express the PAF-R transcript 1 but not the PAF-R transcript 2. Flow cytometry experiments reveal that PAF-R are present on these myeloma cell lines. PAF and the non-metabolizable PAF agonist 1-O-hexadecyl-2-N-methycarbamyl-glycero-3-phosphocholine have no effect on the growth of OPM2, U266, IM9, XG1 and L363 assessed by [3H]thymidine incorporation into DNA. As a positive control of PAF effect on myeloma cells, PAF (1 microM) enhances by 100% the immunoglobulin synthesis by IM9 cells cultured for 48 h. In conclusion the five myeloma cell lines used in this study metabolize PAF through the deacetylation/reacylation pathway. They express membrane PAF-R through the PAF-R mRNA transcript 1 but PAF does not affect their growth.
Desplat
V
V
Laboratoire d'Hématologie Expérimentale, Faculté de Médecine, Limoges, France.
Dulery
C
C
Faucher
J L
JL
Praloran
V
V
Denizot
Y
Y
D002455:Cell Division / Q000187:drug effects; D006801:Humans; D009101:Multiple Myeloma / Q000378:metabolism* / Q000473:pathology*; D010972:Platelet Activating Factor / Q000378:metabolism* / Q000494:pharmacology; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D011869:Radioligand Assay; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014407:Tumor Cells, Cultured
D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor