Aberrant c-myc RNAs of Burkitt's lymphoma cells have longer half-lives.
BL67 and BL18 are Burkitt's lymphoma cell lines with t(8;14) translocations (the breakpoint is in the first exon and first intron, respectively) in which the mu-heavy chain switch region is fused to the c-myc gene in head to head orientation. In both cell lines only aberrant c-myc RNAs are found. BL67 cells contain two c-myc RNA species of 2.4 and 3.5 kb. The 2.4-kb RNA is initiated at several cryptic promoters in the first intron. The 3.5-kb RNA is transcribed from the immunoglobulin heavy chain anti-sense strand across the breakpoint of the translocation into the first exon of the c-myc gene and is then normally spliced using the physiological splice donor and acceptor sites of the c-myc gene. BL18 contains c-myc RNA of 2.4 kb initiated at cryptic promoters in the first intron and additional RNAs of 0.90 kb and 0.74 kb transcribed from the dual c-myc promoters on the reciprocal fragment of the translocation. The cytoplasmic turnover of these RNAs differs significantly from that of the normal c-myc message. The 3.5-kb RNA of BL67 cells and the 0.90-kb and 0.74-kb RNAs of BL18 cells, which are both hybrid molecules consisting of c-myc and immunoglobulin sequences, have a half-life of several hours in contrast to the normal c-myc message with a half-life of 15 min. The aberrant 2.4-kb c-myc RNAs of BL67 and BL18 cells are also more stable than the normal c-myc message and disappear with a half-life of 50 min.(ABSTRACT TRUNCATED AT 250 WORDS)
D002051:Burkitt Lymphoma / Q000235:genetics*; D002460:Cell Line; D002906:Chromosomes, Human, 6-12 and X; D004262:DNA Restriction Enzymes; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D009693:Nucleic Acid Hybridization; D009857:Oncogenes; D011401:Promoter Regions, Genetic; D012334:RNA, Neoplasm / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D014158:Transcription, Genetic; D014178:Translocation, Genetic
D012334:RNA, Neoplasm; D004262:DNA Restriction Enzymes