Schwab M, Klempnauer K H, Alitalo K, Varmus H, Bishop M
Mol Cell Biol. 1986 Jul;6(7):2752-5. doi: 10.1128/mcb.6.7.2752-2755.1986.
The proto-oncogene c-myc is amplified in sublines of human COLO 320 cells carrying either homogeneously staining chromosomal regions or double minutes. COLO 320 cells carrying homogeneously staining chromosomal regions have 15 to 20 copies of an apparently normal c-myc allele and 1 to 2 copies of an abnormal c-myc allele lacking exon 1 and express high levels of a normal c-myc mRNA 2.5 kilobases in size. COLO 320 cells carrying double minutes have about 25 copies each of the normal allele and the abnormal allele but express preferentially an abnormal c-myc mRNA 2.2 kilobases in size. Nucleotide sequence analyses revealed that the break point of rearrangement resulting in the loss of exon 1 in the abnormal allele lies within a region frequently rearranged in human and murine B-cell tumors.
原癌基因c-myc在携带均匀染色染色体区域或双微体的人COLO 320细胞亚系中发生扩增。携带均匀染色染色体区域的COLO 320细胞有15至20个明显正常的c-myc等位基因拷贝和1至2个缺少外显子1的异常c-myc等位基因拷贝，并表达高水平的大小为2.5千碱基的正常c-myc mRNA。携带双微体的COLO 320细胞每个正常等位基因和异常等位基因各有大约25个拷贝，但优先表达大小为2.2千碱基的异常c-myc mRNA。核苷酸序列分析显示，导致异常等位基因中外显子1缺失的重排断点位于人类和鼠类B细胞肿瘤中经常发生重排的区域内。
