title: Multiple isoforms of PAX5 are expressed in both lymphomas and normal B-cells.
abstract: The transcription factor Pax5 plays a critical role in B cell development. It has been shown that alternative splicing of its gene (PAX5) produces several distinct transcripts that modify the amino acid sequence of the putative Pax5 proteins. Subsequent studies have attempted to correlate the expression of PAX5 isoforms with certain B-cell lymphomas, the conclusions of which suggest that altered isoform expression is involved in lymphomagenesis. However, in the absence of definitive data for PAX5 isoform expression patterns in normal B cells it is difficult to confirm whether aberrant isoform expression can indeed be correlated with disease. Using a high-resolution method of analysis of reverse transcription polymerase chain reaction products, we sought to analyse the expression of the different PAX5 isoforms in normal B-cells as well as a number of B-cell lymphoma and chronic lymphocytic leukaemia cases. It was found that multiple PAX5 isoforms were expressed in both normal and malignant B cells. Immunodetection and polysomal RNA analyses also confirmed that the different PAX5 mRNAs were translated into their corresponding proteins. No consistent deregulation of PAX5 isoform expression was observed in B-cell lymphomas, but rather, complex isoform expression patterns were found in normal B cell as well as B-cell lymphoma and CLL cases.
authors.affiliation: Atlantic Cancer Research Institute, Moncton, NB, Canada.
authors.forename: Jean-René
authors.initials: JR
authors.lastname: Arseneau
authors.forename: Mark
authors.initials: M
authors.lastname: Laflamme
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Lewis
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Maïcas
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Ouellette
mesh_terms: D017398:Alternative Splicing; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D015153:Blotting, Western / Q000379:methods; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000378:metabolism; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000378:metabolism*; D046210:Microfluidic Analytical Techniques / Q000379:methods; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D051757:PAX5 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014407:Tumor Cells, Cultured
chemical_list: D009363:Neoplasm Proteins; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human; D020033:Protein Isoforms; D012333:RNA, Messenger; D012334:RNA, Neoplasm