Publication Date
2014
Journal Title
FASEB J
Abstract
Within T-cell-dependent germinal centers, p53 gene transcription is repressed by Bcl-6 and is thus less vulnerable to mutation. Malignant lymphomas within inflamed extranodal sites exhibit a relatively high incidence of p53 mutations. The latter might originate from normal B-cell clones manifesting activation-induced cytosine deaminase (AID) and up-regulated p53 following T-cell-independent (TI) stimulation. We here examine p53 gene transcription in such TI clones, with a focus on modulatory effects of prostaglandin E-2 (PGE(2)), and evaluate progeny for p53 mutations. Resting IgM(+)IgD(+)CD27(-) B cells from human tonsils were labeled with CFSE and stimulated in vitro with complement-coated antigen surrogate, IL-4, and BAFF +/- exogenous PGE(2) (50 nM) or an analog specific for the EP2 PGE(2) receptor. We use flow cytometry to measure p53 and AID protein within variably divided blasts, qRT-PCR of p53 mRNA from cultures with or without actinomycin D to monitor mRNA transcription/stability, and single-cell p53 RT-PCR/sequencing to assess progeny for p53 mutations. We report that EP2 signaling triggers increased p53 gene transcriptional activity in AID(+) cycling blasts (P
Volume Number
28
Issue Number
2
Pages
627-643
Document Type
Article
Status
Faculty, Northwell Researcher
Facility
School of Medicine; Northwell Health
Primary Department
Molecular Medicine
Additional Departments
General Internal Medicine
PMID
DOI
10.1096/fj.13-237792