title: VEGFR-1 (FLT-1), beta1 integrin, and hERG K+ channel for a macromolecular signaling complex in acute myeloid leukemia: role in cell migration and clinical outcome.
abstract: Leukemia cell motility and transendothelial migration into extramedullary sites are regulated by angiogenic factors and are considered unfavorable prognostic factors in acute leukemias. We have studied cross talk among (1) the vascular endothelial growth factor receptor-1, FLT-1; (2) the human eag-related gene 1 (hERG1) K(+) channels; and (3) integrin receptors in acute myeloid leukemia (AML) cells. FLT-1, hERG1, and the beta(1) integrin were found to form a macromolecular signaling complex. The latter mostly recruited the hERG1B isoform of hERG1 channels, and its assembly was necessary for FLT-1 signaling activation and AML cell migration. Both effects were inhibited when hERG1 channels were specifically blocked. A FLT-1/hERG1/beta(1) complex was also observed in primary AML blasts, obtained from a population of human patients. The co-expression of FLT-1 and hERG1 conferred a pro-migratory phenotype to AML blasts. Such a phenotype was also observed in vivo. The hERG1-positive blasts were more efficient in invading the peripheral circulation and the extramedullary sites after engraftment into immunodeficient mice. Moreover, hERG1 expression in leukemia patients correlated with a higher probability of relapse and shorter survival periods. We conclude that in AML, hERG1 channels mediate the FLT-1-dependent cell migration and invasion, and hence confer a greater malignancy.
authors.affiliation: Department of Experimental Pathology and Oncology, University of Firenze, Firenze, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Pillozzi
authors.forename: Maria Felice
authors.initials: MF
authors.lastname: Brizzi
authors.forename: Pietro Antonio
authors.initials: PA
authors.lastname: Bernabei
authors.forename: Benedetta
authors.initials: B
authors.lastname: Bartolozzi
authors.forename: Roberto
authors.initials: R
authors.lastname: Caporale
authors.forename: Venere
authors.initials: V
authors.lastname: Basile
authors.forename: Vieri
authors.initials: V
authors.lastname: Boddi
authors.forename: Luigi
authors.initials: L
authors.lastname: Pegoraro
authors.forename: Andrea
authors.initials: A
authors.lastname: Becchetti
authors.forename: Annarosa
authors.initials: A
authors.lastname: Arcangeli
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D002448:Cell Adhesion; D002465:Cell Movement; D002470:Cell Survival; D051638:Ether-A-Go-Go Potassium Channels / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D019012:Integrin beta1 / Q000378:metabolism*; D007951:Leukemia, Myeloid / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism*
chemical_list: D051638:Ether-A-Go-Go Potassium Channels; D019012:Integrin beta1; C496884:KCNH1 protein, human; D034741:RNA, Small Interfering; D040281:Vascular Endothelial Growth Factor Receptor-1; D051057:Proto-Oncogene Proteins c-akt