Expression of Bcl-2 and Bcl-2-Ig fusion transcripts in normal and neoplastic cells.
We examined the expression of the Bcl-2 gene at chromosome segment 18q21, that is translocated into the Ig heavy chain gene locus in t(14;18) bearing lymphomas. Bcl-2, while B cell associated, is expressed in a variety of hematopoietic lineages including T cells. Bcl-2 mRNA levels are high during pre-B cell development, the time at which the t(14;18) translocation occurs, but are down regulated with maturation. Like certain other oncogenes, Bcl-2 is quiescent in resting B cells but up-regulated with B cell activation. Mature B cell lymphomas with a t(14;18) have log-folds more mRNA than matched counterparts without the translocation. A sensitive S1 protection assay revealed that all transcripts in t(14;18) B cells were Bcl-2-Ig fusion mRNAs and originated from the translocated allele. Thus, there is a marked deregulation of Bcl-2 when it is introduced into the Ig locus in t(14;18) lymphomas.
D001402:B-Lymphocytes / Q000378:metabolism; D002454:Cell Differentiation; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D005786:Gene Expression Regulation; D006801:Humans; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000378:metabolism*; D008223:Lymphoma / Q000235:genetics*; D009857:Oncogenes; D012333:RNA, Messenger / Q000235:genetics; D013601:T-Lymphocytes / Q000378:metabolism; D014158:Transcription, Genetic; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger