title: Gene expression analysis of angioimmunoblastic lymphoma indicates derivation from T follicular helper cells and vascular endothelial growth factor deregulation.
abstract: Angioimmunoblastic lymphoma (AILT) is the second most common subtype of peripheral T-cell lymphoma (PTCL) and is characterized by dismal prognosis. Thus far, only a few studies have dealt with its molecular pathogenesis. We performed gene expression profile (GEP) analysis of six AILT, six anaplastic large cell lymphomas (ALCL), 28 PTCL-unspecified (PTCL/U), and 20 samples of normal T lymphocytes (including CD4(+), CD8(+), and activated and resting subpopulations), aiming to (a) assess the relationship of AILT with other PTCLs, (b) establish the relationship between AILT and normal T-cell subsets, and (c) recognize the cellular programs deregulated in AILT possibly looking for novel potential therapeutic targets. First, we found that AILT and other PTCLs have rather similar GEP, possibly sharing common oncogenic pathways. Second, we found that AILTs are closer to activated CD4(+), rather than to resting or CD8(+) lymphocytes. Furthermore, we found that the molecular signature of follicular T helper cells was significantly overexpressed in AILT, reinforcing the idea that AILT may arise from such cellular counterpart. Finally, we identified several genes deregulated in AILT, including PDGFRA, REL, and VEGF. The expression of several molecules was then studied by immunohistochemistry on tissue microarrays containing 45 independent AILT cases. Notably, we found that the vascular endothelial growth factor (VEGF) was expressed not only by reactive cells, but also by neoplastic cells, and that nuclear factor-kappaB (NF-kappaB) activation is uncommon in AILT, as suggested by frequent exclusively cytoplasmic c-REL localization. Our study provides new relevant information on AILT biology and new candidates for possible therapeutic targets such as PDGFRA (platelet-derived growth factor alpha) and VEGF.
authors.affiliation: Institute of Hematology and Medical Oncology L. and A. Seràgnoli, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy. pierpaolo.piccaluga@unibo.it
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Piccaluga
authors.forename: Claudio
authors.initials: C
authors.lastname: Agostinelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Califano
authors.forename: Antonino
authors.initials: A
authors.lastname: Carbone
authors.forename: Luca
authors.initials: L
authors.lastname: Fantoni
authors.forename: Sergio
authors.initials: S
authors.lastname: Ferrari
authors.forename: Anna
authors.initials: A
authors.lastname: Gazzola
authors.forename: Annunziata
authors.initials: A
authors.lastname: Gloghini
authors.forename: Simona
authors.initials: S
authors.lastname: Righi
authors.forename: Maura
authors.initials: M
authors.lastname: Rossi
authors.forename: Enrico
authors.initials: E
authors.lastname: Tagliafico
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Zinzani
authors.forename: Simonetta
authors.initials: S
authors.lastname: Zupo
authors.forename: Michele
authors.initials: M
authors.lastname: Baccarani
authors.forename: Stefano A
authors.initials: SA
authors.lastname: Pileri
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007107:Immune System; D007150:Immunohistochemistry / Q000379:methods; D008223:Lymphoma / Q000235:genetics* / Q000378:metabolism*; D016411:Lymphoma, T-Cell, Peripheral / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D020569:Proto-Oncogene Proteins c-rel / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
chemical_list: D016328:NF-kappa B; D020569:Proto-Oncogene Proteins c-rel; D042461:Vascular Endothelial Growth Factor A