title: FOXP1 molecular cytogenetics and protein expression analyses in primary cutaneous large B cell lymphoma, leg-type.
abstract: FOXP1 protein is expressed in normal activated B cells and overexpressed in a subset of diffuse large B-cell lymphomas, including primary cutaneous large B-cell lymphomas (PCLBCL), leg type. High expression of FOXP1 has been associated to an unfavourable prognosis with independent survival significance. However, little is known regarding the mechanisms underlying the overexpression of FOXP1 in PCLBCL, leg type. Our aims were to analyze FOXP1 cytogenetic status and protein expression in a series of PCLBCL, leg type. Finally, we compared the observed results with those obtained in a group of patients with primary cutaneous follicle centre lymphoma (PCFCL). Fifteen patients with PCLBCL, leg type and nine patients with primary cutaneous follicle centre lymphoma (PCFCL) were included in the study. For each biopsy specimen, FOXP1 translocation and copy number changes were evaluated by fluorescence in situ hybridization (FISH) and protein expression by immunohistochemistry (IHC). Immunohistochemistry showed FOXP1 staining in 13 PCLBCL, leg type, whereas all PCFCL were negative. FISH analysis disclosed no translocations involving FOXP1 gene in any of the cases. However, FOXP1 gene gains (3 to 4 copies) were observed in 82% of samples of PCLBCL, leg type and in 37% of PCFCL. FOXP1 expression was independent from FOXP1 translocation. Our results confirm that overexpression of FOXP1 is present in a considerable proportion of PCLBCL, leg type and might indicate an unfavourable prognosis. Mechanisms not related to translocation seem to be responsible for this overexpression.
authors.affiliation: Servei de Patologia (Laboratori de Citogenètica i Biologia Molecular), IMIM-Hospital del Mar, GRETNHE, IMIM. Barcelona, Spain. bespinet@parcdesalutmar.cat
authors.forename: Blanca
authors.initials: B
authors.lastname: Espinet
authors.forename: Adriana
authors.initials: A
authors.lastname: García-Herrera
authors.forename: Fernando
authors.initials: F
authors.lastname: Gallardo
authors.forename: Cristina
authors.initials: C
authors.lastname: Baró
authors.forename: Rocío
authors.initials: R
authors.lastname: Salgado
authors.forename: Octavio
authors.initials: O
authors.lastname: Servitje
authors.forename: Teresa
authors.initials: T
authors.lastname: Estrach
authors.forename: Lluís
authors.initials: L
authors.lastname: Colomo
authors.forename: Vicenç
authors.initials: V
authors.lastname: Romagosa
authors.forename: Carlos
authors.initials: C
authors.lastname: Barranco
authors.forename: Sergi
authors.initials: S
authors.lastname: Serrano
authors.forename: Elias
authors.initials: E
authors.lastname: Campo
authors.forename: Ramon Ma
authors.initials: RM
authors.lastname: Pujol
authors.forename: Francesc
authors.initials: F
authors.lastname: Solé
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D002869:Chromosome Aberrations; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics* / Q000378:metabolism; D018628:Gene Dosage; D020440:Gene Duplication; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007866:Leg / Q000473:pathology; D008224:Lymphoma, Follicular / Q000235:genetics / Q000378:metabolism; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C486626:FOXP1 protein, human; D051858:Forkhead Transcription Factors; D012097:Repressor Proteins