Preferential expression of truncated isoforms of FOXP1 in primary central nervous system lymphoma.
Forkhead box P1 (FOXP1) protein is a transcription factor involved in cell signaling and regulation of gene expression. The overexpression of FOXP1 in a subgroup of systemic diffuse large B-cell lymphomas has been associated with an exceptionally poor clinical outcome. Data on FOXP1 expression in primary central nervous system lymphomas (PCNSL), that is, diffuse large B-cell lymphomas confined to the central nervous system, are not yet available. We analyzed 43 PCNSL from immunocompetent patients. Immunohistochemistry showed expression of FOXP1 protein in 21 (88%) of 24 cases. All 19 PCNSL analyzed by quantitative gene expression analysis showed overexpression of truncated FOXP1 Isoforms 3 and 9 and downregulation of normal-size FOXP1 compared with nonmalignant germinal center B cells, the normal counterpart of PCNSL tumor cells. Thus, truncated FOXP1 isoforms are preferentially overexpressed in PCNSL as they are in diffuse large B-cell lymphomas. Although the mechanisms are presently unclear, this overexpression may contribute to a poor prognosis in PCNSL.
Courts
Cornelius
C
Department of Neuropathology, University Hospital of Cologne, Cologne.
Brunn
Anna
A
Montesinos-Rongen
Manuel
M
Siemer
Dörte
D
Hans
Volkmar
V
Paulus
Werner
W
Wiestler
Otmar D
OD
Küppers
Ralf
R
Siebert
Reiner
R
Deckert
Martina
M
D000368:Aged; D015153:Blotting, Western; D016543:Central Nervous System Neoplasms / Q000235:genetics* / Q000378:metabolism; D005260:Female; D051858:Forkhead Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
C486626:FOXP1 protein, human; D051858:Forkhead Transcription Factors; D020033:Protein Isoforms; D012097:Repressor Proteins