title: Diverse expression of cytosolic phospholipase A2, 5-lipoxygenase and prostaglandin H synthase 2 in acute pre-B-lymphocytic leukaemia cells.
abstract: Several lines of evidence suggest that phospholipases A2, leukotrienes and prostaglandins play a role in the proliferation of haemopoietic cells. The expression of genes involved in the biosynthesis of leukotrienes and prostaglandins was investigated in peripheral B lymphoblasts, isolated from eight patients with acute pre-B-lymphocytic leukaemia (pre B-ALL). RT-PCR analysis demonstrated that four of the investigated pre-B-ALL clones expressed the gene coding for cytosolic phospholipase A2 (cPLA2), but not the gene coding for 5-lipoxygenase. In contrast, the remaining four pre-B-ALL clones expressed 5-lipoxygenase but not cPLA2, suggesting that the transcriptional regulation of these two genes are different and that their cellular functions are not linked to each other. The capacity of pre B-ALL cells to produce LTB4 and to express the 5-lipoxygenase protein, correlated with the expression of 5-lipoxygenase mRNA. All pre-B-ALL clones expressed genes coding for 5-lipoxygenase activating protein (FLAP), leukotriene A4 hydrolase and prostaglandin (PG)H synthase 1. Seven of the eight pre B-ALL clones expressed PGH synthase 2. In comparison, normal tonsillar B cells did not express cPLA2 or PGH synthase 2.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Feltenmark
authors.forename: G
authors.initials: G
authors.lastname: Runarsson
authors.forename: P
authors.initials: P
authors.lastname: Larsson
authors.forename: P J
authors.initials: PJ
authors.lastname: Jakobsson
authors.forename: M
authors.initials: M
authors.lastname: Björkholm
authors.forename: H E
authors.initials: HE
authors.lastname: Claesson
mesh_terms: D058927:5-Lipoxygenase-Activating Proteins; D000293:Adolescent; D000328:Adult; D001094:Arachidonate 5-Lipoxygenase / Q000096:biosynthesis / Q000235:genetics*; D001402:B-Lymphocytes / Q000201:enzymology; D001483:Base Sequence; D002051:Burkitt Lymphoma / Q000201:enzymology / Q000235:genetics*; D002352:Carrier Proteins / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000096:biosynthesis / Q000235:genetics*; D054467:Phospholipases A2; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D058927:5-Lipoxygenase-Activating Proteins; C548592:ALOX5AP protein, human; D002352:Carrier Proteins; D008565:Membrane Proteins; D001094:Arachidonate 5-Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; D010741:Phospholipases A; D054467:Phospholipases A2