title: High expression of CEACAM6 and CEACAM8 mRNA in acute lymphoblastic leukemias.
abstract: CEACAM family members are a set of widely expressed proteins involved in several biological functions, including cell adhesion, migration, signal transduction, and the regulation of gene expression. Abnormal overexpression and downregulation of some CEACAMs have been described in tumor cells. Monoclonal antibodies grouped in the CD66 cluster recognize CEACAM members. Ectopic CD66 expression is commonly detected in B-cell lineage acute lymphoblastic leukemia (ALL). To investigate the CEACAM messenger RNA (RNA) expression in leukemic blasts, we performed a quantitative polymerase chain reaction (RQ-PCR) analysis in purified RNA samples from a consecutive series of acute leukemias (135 patients). Most B-cell lineage ALL expressed CD66 (79.5%), whereas no single case of T-cell lineage ALL disclosed CD66 reactivity (0%). All the BCR-ABL+ ALL cases showed CD66 expression. CD66 was positive even in cases without CD10 expression (72.7%) and/or with MLL rearrangements. Despite the sharp contrast between T-ALL and B-ALL in CD66 reactivity, CEACAM patterns were comparable, and only minor differences for CEACAM1 and CEACAM8 were detected. All the leukemic samples showed overexpression of CEACAM6 and 8 when compared with normal granulocytes. These results were confirmed by dilutional experiments. The leukemic pattern paralleled the normal regenerating bone marrow with lower values for CEACAM1. In line with the results for CD66 reactivity, neoplastic cell lines had a uniform low expression of CEACAM family members. It remains to be investigated whether these CEACAM disturbances provide growth advantages to tumoral cells by inhibiting the anoikis process.
authors.affiliation: Department of Hematology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Adriana
authors.initials: A
authors.lastname: Lasa
authors.forename: Elena
authors.initials: E
authors.lastname: Serrano
authors.forename: Maite
authors.initials: M
authors.lastname: Carricondo
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Carnicer
authors.forename: Salut
authors.initials: S
authors.lastname: Brunet
authors.forename: Isabel
authors.initials: I
authors.lastname: Badell
authors.forename: Jorge
authors.initials: J
authors.lastname: Sierra
authors.forename: Anna
authors.initials: A
authors.lastname: Aventín
authors.forename: Josep F
authors.initials: JF
authors.lastname: Nomdedéu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D001752:Blast Crisis / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D005260:Female; D058851:GPI-Linked Proteins; D015973:Gene Expression Regulation, Leukemic; D016313:Genes, abl / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D015260:Neprilysin / Q000096:biosynthesis / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics
chemical_list: D015703:Antigens, CD; C069847:CD66 antigens; C504117:CEACAM6 protein, human; C504120:CEACAM8 protein, human; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D015260:Neprilysin