Characterization of C2-ceramide-resistant HL-60 subline (HL-CR): involvement of PKC delta in C2-ceramide resistance.
We have established a C2-ceramide-resistant HL-60 subline (HL-CR). HL-CR cells were resistant not only to C2-ceramide but also to various anticancer drugs. HL-CR cells did not respond to differentiation-inducing reagents including 1alpha,25-dihydroxyvitamin D(3), retinoic acid, and 12-O-tetradecanoylphorbol-13-acetate (TPA). TPA induced apoptosis in HL-CR cells much slower than in parental HL-60 cells. As it was reported that PKC isozymes were involved in C2-ceramide-induced apoptosis, we investigated the role of PKC isozymes in C2-ceramide resistance in HL-CR cells. The protein level of PKC delta was lower in HL-CR cells than in parental HL-60 cells, whereas the levels of PKC alpha, betaI, epsilon, and zeta were rather higher in HL-CR cells than in parental cells. Translocation of PKC delta from membrane to cytosol was induced by C2-ceramide in HL-CR cells as well as in wild-type HL-60 cells. Furthermore, overexpression of PKC delta in HL-CR cells potentiated C2-ceramide- and TPA-induced apoptosis and growth inhibition. These results suggest a role for ceramide in apoptosis and differentiation in HL-60 cells, and also suggest that PKC delta might be involved in ceramide- and TPA-induced apoptosis.
Department of Preventive and Community Dentistry, Osaka Dental University, 8-1, Kuzuhahanazono-cho, Hirakata, Osaka 573-1121, Japan.
Kentaro
K
Yakushiji
Hirofumi
H
Sawai
Shinjiro
S
Kawai
Masaki
M
Kambara
Naochika
N
Domae
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002762:Cholecalciferol / Q000494:pharmacology; D004351:Drug Resistance / Q000502:physiology*; D005057:Eukaryotic Cells / Q000187:drug effects / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000235:genetics; D018922:HL-60 Cells; D006801:Humans; D007527:Isoenzymes / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D051745:Protein Kinase C-delta; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology
D000970:Antineoplastic Agents; D007527:Isoenzymes; C064769:N-acetylsphingosine; D002762:Cholecalciferol; D014212:Tretinoin; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D013110:Sphingosine; D013755:Tetradecanoylphorbol Acetate