Eick D, Polack A, Kofler E, Lenoir G M, Rickinson A B, Bornkamm G W
Institut für Klinische Molekularbiologie und Tumorgenetik, Hämatologikum der GSF, München, Federal Republic of Germany.
Oncogene. 1990 Sep;5(9):1397-402.
We have studied the allele specific expression of c-myc P0- and P3-RNA in Burkitt's lymphoma (BL) cells. The steady state levels of P0-RNA show considerable variations in BL cells. Expression of P0-RNA was found to be restricted to the translocated allele, but could be induced by TPA from the normal allele. P0-transcription was particularly sensitive to inhibitors of protein synthesis compared to expression of P1-, P2- and P3-RNA. Transcription of P3-RNA is initiated in the first intron of the c-myc gene and has previously been described to be specific for translocated c-myc alleles in BL cells broken within exon 1 or intron 1. Here we show that P3-RNA is also expressed from an unrearranged c-myc gene. In the BL cell line Raji, substantial amounts of c-myc RNA are derived from the P3-promoter of the normal allele. This indicates that repression of the normal allele in BL cells does not include the P3-promoter. The potential coding capacity of P3-RNA is discussed.
我们研究了伯基特淋巴瘤（BL）细胞中c-myc P0-RNA和P3-RNA的等位基因特异性表达。P0-RNA的稳态水平在BL细胞中显示出相当大的差异。发现P0-RNA的表达仅限于易位等位基因，但可被佛波酯从正常等位基因诱导表达。与P1-RNA、P2-RNA和P3-RNA的表达相比，P0转录对蛋白质合成抑制剂特别敏感。P3-RNA的转录起始于c-myc基因的第一个内含子，此前已描述其在第1外显子或第1内含子内断裂的BL细胞中对易位的c-myc等位基因具有特异性。在这里我们表明，P3-RNA也从未重排的c-myc基因表达。在BL细胞系Raji中，大量的c-myc RNA来源于正常等位基因的P3启动子。这表明BL细胞中正常等位基因的抑制不包括P3启动子。本文讨论了P3-RNA的潜在编码能力。
