Genomic imbalances in drug-resistant T-cell acute lymphoblastic CEM leukemia cell lines
Genomic imbalances in drug-resistant T-cell acute lymphoblastic CEM leukemia cell lines
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DOI：
10.1006/bcmd.2002.0530
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发表时间：
2002-07-01
影响因子：
2.3
通讯作者：
Gebhart, E
中科院分区：
文献类型：
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作者：
Efferth, T;Verdorfer, I;Gebhart, E
选择了10种T细胞急性淋巴母细胞（T-ALL）PEM细胞系，用于对甲氨蝶呤（PEM/MTX 60 PGA、PEM/MTX 140 LV、PEM/MTX 1500 LV、PEM/MTX 5000 PGA、PEM/MTXR 1、PEM/MTXR 2和PEM/MTRX 3）、多柔比星（PEM/ADR 5000）、长春新碱（PEM/VCR 1000）或羟基脲耐药。(CEM/HUR 90），并使用比较基因组杂交分析亲本药物敏感性CCRF-CEM细胞。大多数基因组不平衡并不是耐药性的特异性，因为它们在亲本和耐药株系中都有发现。所有或大多数分析的细胞系共有三种畸变：dim（5 q35）、dim（9 p21 p24）和enh（20 q）。我们关注的是那些特别存在于耐药细胞而不是药物敏感细胞中的不平衡。所有甲氨蝶呤耐药细胞系的特征在于5 q13的增强或扩增。甲氨蝶呤抗性赋予二氢叶酸还原酶（DBFR）基因位于该位点。通过PCR分析验证DHFR的获得。CEM/MTX 60 PGA、CEM/MTX 140 LV、CEM/MTX 1500 LV和CEM/MTX 5000 PGA显示增强（14 q21 qter）和CEM/MTX 5000 PGA放大（5 p13 p15.2）。这两个位点含有亚甲基四氢叶酸脱氢酶（MTHFD 1）和5-甲基四氢叶酸-高半胱氨酸甲基转移酶还原酶（MTRR）基因，这两个基因都参与叶酸代谢。它们的增加表明在甲氨蝶呤耐药性中的作用。在CEM/MTXR 2、CEM/MTXR 3和CEM/ADR 5000中发现了4 q35的缺失，其中凋亡前caspase-3基因位于该缺失。CEM/ADR 5000和CEM/MTX 5000 PGA细胞中9 q31的硫氧还蛋白（thioredoxin，TXN）位点表达增强。2 p22 pter在抗羟基脲的CEM/HUR 90细胞中表达增加。核糖核苷酸还原酶多肽M2（RRM 2），其赋予对羟基脲的抗性，位于该基因座。耐药细胞系中的其他特定基因组失衡为dim（1p36.5）、enh（4p）、dim（8 p22 pter）、enh（12 p13）、dim（17 p）、enh（18 q12）、enh（21q22.2）、dim（21q22.2）和dim（22 q13）。对所有基因组不平衡进行分层聚类分析和聚类图像映射，以确定细胞系中染色体畸变的概况。所获得的树状图允许将一个或大多数细胞系常见的不平衡与其他更个体的畸变分离。此外，甲氨蝶呤耐药细胞系聚集在一起。我们未来的努力将针对那些涉及未知候选耐药基因的不平衡。(C)2002 Elsevier Science（美国）。
Ten T-cell acute lymphoblastic (T-ALL) CEM cell lines selected for resistance toward methotrexate (CEM/MTX60PGA, CEM/MTX140LV, CEM/MTX1500LV, CEM/MTX5000PGA, CEM/MTXR1, CEM/MTXR2, and CEM/MTRX3), doxorubicin (CEM/ADR5000), vincristine (CEM/VCR1000), or hydroxyurea. (CEM/HUR90), respectively, and parental drug-sensitive CCRF-CEM cells were analyzed using comparative genomic hybridization. Most genomic imbalances were not specific for drug resistance, as they were found in both parental and drug-resistant lines. Three aberrations were common to all or most cell lines analyzed: dim(5q35), dim(9p21p24), and enh(20q). We were concerned on those imbalances which were specifically present in drug-resistant but not in drug-sensitive cells. All methotrexate-resistant cell lines were characterized by an enhancement or an amplification of 5q13. The methotrexate resistance-conferring dihydrofolate reductase (DBFR) gene is located at this locus. Gain of DHFR was verified by PCR analyses. CEM/MTX60PGA, CEM/MTX140LV, CEM/MTX1500LV, and CEM/MTX5000PGA showed enh(14q21qter) and CEM/MTX5000PGA amp(5p13p15.2). These two loci harbor the methylenetetrahydrofolate dehydrogenase (MTHFD1) and 5-methyltetrahdrofolate-homocysteine methyltransferase reductase (MTRR) genes, both of which are involved in folate metabolism. Their gain indicates a role in methotrexate resistance. A loss of 4q35 was found in CEM/MTXR2, CEM/MTXR3, and CEM/ADR5000 where the proapoptotic caspase-3 gene is located. The thioredoxin (TXN) locus 9q31 was enhanced in CEM/ADR5000 and CEM/MTX5000PGA cells. 2p22pter was increased in hydroxyurea-resistant CEM/HUR90 cells. Ribonucleotide reductase polypeptide M2 (RRM2), which confers resistance to hydroxyurea, resides at this locus. Other specific genomic imbalances in drug-resistant cell lines were dim(1p36.5), enh(4p), dim(8p22pter), enh(12p13), dim(17p), enh(18q12), enh(21q22.2), dim(21q22.2), and dim(22q13). All genomic imbalances were subjected to hierarchical cluster analysis and clustered image mapping to identify profiles of chromosomal aberrations in the cell lines. The obtained dendrograms allowed separation of imbalances common to a or most cell lines from other more individual aberrations. Furthermore, methotrexate-resistant cell lines clustered together. Our future efforts will be directed toward those imbalances which implicate still unknown candidate drug resistance genes. (C) 2002 Elsevier Science (USA).