Brennscheidt U, Eick D, Kunzmann R, Martens U, Kiehntopf M, Mertelsmann R, Herrmann F
Abteilung für Hmatologie und Onkologie, Universität Freiburg, Germany.
Leukemia. 1994 May;8(5):897-902.
The c-myc oncogene recently shown to act as a transcription factor, is involved in cellular proliferation. Deregulation of this gene can be one step in malignant transformation. In Burkitt's lymphoma (BL) the c-myc gene is consistently involved in chromosomal translocations and the first exon of the gene has been found to be a frequent target of somatic mutations. These mutations are believed to interfere with normal transcriptional regulation of the gene. We demonstrate a case of the rare prolymphocytic leukemia (PLL), a variant of chronic lymphocytic leukemia (CLL), that shows multiple Burkitt-like mutations in the first exon of c-myc and one nonconservative point mutation in the coding exon 2. Cytogenetic analysis revealed involvement of both chromosomes 8 in chromosomal translocations. Both chromosomes 8 are broken at (q23), the c-myc gene locus. Since the patient's leukemia cells exhibited high expression levels of the mutated allele of the c-myc mRNA, the point mutations alone may have accounted for transcriptional deregulation.
最近显示可作为转录因子发挥作用的c-myc癌基因，参与细胞增殖。该基因的失调可能是恶性转化的一个步骤。在伯基特淋巴瘤（BL）中，c-myc基因一直参与染色体易位，并且该基因的第一个外显子已被发现是体细胞突变的常见靶点。据信这些突变会干扰该基因的正常转录调控。我们展示了一例罕见的幼淋巴细胞白血病（PLL）病例，这是慢性淋巴细胞白血病（CLL）的一种变体，其在c-myc的第一个外显子中显示出多个伯基特样突变，并且在编码外显子2中有一个非保守点突变。细胞遗传学分析显示8号染色体均参与了染色体易位。两条8号染色体均在（q23）即c-myc基因位点处断裂。由于患者的白血病细胞表现出c-myc mRNA突变等位基因的高表达水平，仅这些点突变可能就导致了转录失调。
