Lafage-Pochitaloff M, Courcoul M, Simonetti J, Sainty D, Dastugue N, Tabilio A, Hagemeijer A, Birg F
Unité 119, Institut National de la Santé et de la Recherche Médicale, Marseille, France.
Genes Chromosomes Cancer. 1992 Jul;5(1):1-13. doi: 10.1002/gcc.2870050102.
The translocation t(3;21)(q26;q22) is a rare recurring clonal abnormality, either preceding or associated with blast crisis in Philadelphia chromosome-positive chronic myeloid leukemia (CML) patients. We previously localized the chromosomal breakpoints at 3q26.2 and 21q22.2, using high resolution chromosomal analysis. Two genes of interest are localized near the breakpoints, the transferrin receptor gene and the ETS2 proto-oncogene. Their chromosomal localizations, determined by in situ hybridization on normal metaphase cells, were 3q29 and 21q22.3, respectively. They underwent a reciprocal translocation in patients with t(3;21). Their structures were not altered by the translocation, and both were expressed to varying levels in t(3;21) patients. Southern blotting investigations showed that the structure of other single-copy genes, including FIM3, localized near the breakpoints, were not affected by the translocation. An analysis of ETS2 expression performed on CML patients without t(3;21) showed the presence of the transcript in 100% of the blast crises, but only in 20% of the chronic-phase patients. Thus ETS2 expression may either be linked to or play a role in CML progression.
易位t(3;21)(q26;q22)是一种罕见的复发性克隆异常，出现在费城染色体阳性慢性髓性白血病（CML）患者的急变期之前或与之相关。我们之前利用高分辨率染色体分析将染色体断点定位在3q26.2和21q22.2。两个感兴趣的基因位于断点附近，即转铁蛋白受体基因和ETS2原癌基因。通过对正常中期细胞进行原位杂交确定它们的染色体定位分别为3q29和21q22.3。在t(3;21)患者中它们发生了相互易位。它们的结构未因易位而改变，并且在t(3;21)患者中均有不同程度的表达。Southern印迹研究表明，包括位于断点附近的FIM3在内的其他单拷贝基因的结构未受易位影响。对无t(3;21)的CML患者进行的ETS2表达分析显示，100%的急变期患者中有该转录本存在，但慢性期患者中只有20%有。因此，ETS2表达可能与CML进展相关或在其中起作用。
