title: Human U251 glioma cell proliferation is suppressed by HET0016 [N-hydroxy-N'-(4-butyl-2-methylphenyl)formamidine], a selective inhibitor of CYP4A.
abstract: We have previously reported that HET0016 [N-hydroxy-N'-(4-butyl-2 methylphenyl)formamidine], a selective inhibitor of CYP4A and thus 20-HETE (20-hydroxyeicosatetraenoic acid) synthesis, inhibits endothelial cell proliferation and decreases angiogenesis induced by human glioma cell U251. A stable 20-HETE agonist, WIT003 [20-hydroxyeicosa-5(Z),14(Z)-dienoic acid (1 microM)], increased U251 cell proliferation from 3.9- to 4.8-folds from T(0) (time of the treatment). We examined the effects of HET0016 on the growth of U251. HET0016 inhibited U251 basal cell proliferation in a dose-dependent manner. 10 microM HET0016 suppressed 56% of U251 proliferation and significantly increased the proportions of the cells arrested in the G(0)/G(1) phase of the cell cycle. Exposure to HET0016 (as early as 4 h) reduced protein tyrosine and p42/p44 MAPK (mitogen-activated protein kinase) phosphorylation. Furthermore, HET0016 significantly inhibited the U251 proliferation and phosphorylation of both the epidermal growth factor (EGF) receptor and p42/p44 MAPK induced by EGF. CYP4A mRNA and proteins were both present in U251. This suggests that HET0016 inhibited U251 proliferation by inhibiting 20-HETE synthesis. However, U251 did not synthesize 20-HETE in the presence of arachidonic acid. This implies that HET0016 suppresses U251 proliferation by mechanisms that are not yet clear but may involve activities other than inhibition of 20-HETE synthesis. We concluded that HET0016 may be the prototype of novel compounds that suppress human glioma cell proliferation.
authors.affiliation: Eye Care Services, Henry Ford Hospital, Detroit, MI 48202-3450, USA. mguo1@hfhs.org
authors.forename: Meng
authors.initials: M
authors.lastname: Guo
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Roman
authors.forename: John R
authors.initials: JR
authors.lastname: Falck
authors.forename: Paul A
authors.initials: PA
authors.lastname: Edwards
authors.forename: A Guillermo
authors.initials: AG
authors.lastname: Scicli
mesh_terms: D000578:Amidines / Q000494:pharmacology*; D000970:Antineoplastic Agents; D016718:Arachidonic Acid / Q000378:metabolism; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D042926:Cytochrome P-450 CYP4A / Q000037:antagonists & inhibitors*; D053938:DNA Fragmentation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D066246:ErbB Receptors / Q000187:drug effects; D005434:Flow Cytometry; D005910:Glioma / Q000473:pathology*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis; D020287:In Situ Nick-End Labeling; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects; D012334:RNA, Neoplasm / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013936:Thymidine / Q000378:metabolism
chemical_list: D000578:Amidines; D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; C000708209:HET0016; D006893:Hydroxyeicosatetraenoic Acids; D012334:RNA, Neoplasm; D016718:Arachidonic Acid; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; D042926:Cytochrome P-450 CYP4A; D066246:ErbB Receptors; D019950:Mitogen-Activated Protein Kinase 1; D013936:Thymidine