title: 12-O-tetradecanoylphorbol-13-acetate (TPA) downregulates expression of CD30 in erythroleukemia cell line K562.
abstract: CD30, a member of the tumour necrosis factor/nerve growth factor receptor superfamily, has been thought to have pleiotropic functions on immune response. However, there has been only a little information about the mechanism of CD30 expression. In this study, modulation of the CD30 molecule was investigated by the treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). When cultures were supplemented with TPA, CD30 transcript was downregulated in a dose- and time-dependent manner in the erythroleukemia cell line K562. Half reduction of CD30 transcript, precursor protein and surface protein was at 3 h, 6 h, and 40 h, respectively, by Northern blot and Western blot analyses. This consecutive reduction of both the transcript and proteins suggests that TPA directly inhibits the transcriptional step of CD30, and subsequently CD30 molecules would decrease on the cell surface. To determine whether the protein kinase C (PKC) pathway is involved in this reduction, a PKC inhibitor, 10 microM H-7, was added to the K562 culture. The addition of H-7 recovered the inhibitory effect of TPA, indicating that PKC is involved in the transcription of CD30. When either 2 micrograms/ml actinomycin D or 20 micrograms/ml cycloheximide was added simultaneously with TPA to the culture, the repressive effect of TPA on CD30 was abolished. These results showed that the repression would also partly involve ongoing mRNA and protein synthesis under TPA treatment.
authors.affiliation: First Department of Pathology, School of Medicine, Chiba University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ezawa
authors.forename: K
authors.initials: K
authors.lastname: Harigaya
authors.forename: G
authors.initials: G
authors.lastname: Ishii
authors.forename: N
authors.initials: N
authors.lastname: Nakajima
authors.forename: A
authors.initials: A
authors.lastname: Mikata
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000235:genetics; D001752:Blast Crisis / Q000378:metabolism / Q000473:pathology; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D006207:Half-Life; D006801:Humans; D017730:Ki-1 Antigen / Q000096:biosynthesis* / Q000235:genetics; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism / Q000473:pathology*; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism / Q000473:pathology*; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000951:Antigens, Neoplasm; D004791:Enzyme Inhibitors; D017730:Ki-1 Antigen; D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D003609:Dactinomycin; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D003513:Cycloheximide; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate