Cilloni Daniela, Messa Francesca, Gottardi Enrico, Fava Milena, Arruga Francesca, Defilippi Ilaria, Carturan Sonia, Messa Emanuela, Morotti Alessandro, Giugliano Emilia, Rege-Cambrin Giovanna, Alberti Daniele, Baccarani Michele, Saglio Giuseppe
Division of Hematology and Internal Medicine, Department of Clinical and Biological Sciences, University of Turin, Italy.
Cancer. 2004 Sep 1;101(5):979-88. doi: 10.1002/cncr.20457.
The objective of the current study was to verify the ability to predict response to imatinib therapy using in vitro assays to evaluate the inhibition of Wilms tumor gene (WT1) expression and colony growth after samples obtained from patients with chronic myelogenous leukemia (CML) before the start of treatment were subjected to short-term incubation with imatinib.
WT1 transcript levels and colony growth in bone marrow (BM) samples from 23 patients with CML that was later identified as being responsive to imatinib and from 13 patients with CML that was later identified as not being responsive to imatinib were evaluated after incubation of these samples with imatinib at a concentration of 1 microM for 18 hours. In addition, real-time quantitative polymerase chain reaction (RQ-PCR) analysis of WT1 expression was performed during follow-up, and the results were analyzed for associations with cytogenetic response and with BCR/ABL transcript levels as determined using RQ-PCR analysis.
Before treatment, it was found that WT1 expression was elevated in BM samples obtained from all patients with CML. WT1 expression and colony growth were reduced significantly after an 18-hour incubation with imatinib in samples obtained from patients who were later identified as responders to treatment, but not in samples obtained from patients who did not experience responses to treatment. Inhibition of WT1 expression in vitro was associated with inhibition of imatinib-induced BCR-ABL tyrosine kinase activity, a finding that also has been made in studies involving certain Philadelphia chromosome (Ph)-positive and Ph-negative cell lines.
Inhibition of WT1 transcript levels after a short period of in vitro exposure of pretherapy BM samples to imatinib was correlated with inhibition of colony growth and may represent the basis for an easy test that is capable of predicting the sensitivity of CML to treatment with imatinib for individual patients.
本研究的目的是通过体外试验来验证预测伊马替尼治疗反应的能力，该试验是在慢性髓性白血病（CML）患者治疗开始前获取的样本与伊马替尼进行短期孵育后，评估对威尔姆斯肿瘤基因（WT1）表达的抑制作用和集落生长情况。
将来自23例后来被确定对伊马替尼有反应的CML患者以及13例后来被确定对伊马替尼无反应的CML患者的骨髓（BM）样本，与浓度为1微摩尔的伊马替尼孵育18小时后，评估WT1转录水平和集落生长情况。此外，在随访期间进行WT1表达的实时定量聚合酶链反应（RQ-PCR）分析，并分析结果与细胞遗传学反应以及使用RQ-PCR分析测定的BCR/ABL转录水平之间的关联。
治疗前，发现从所有CML患者获取的BM样本中WT1表达均升高。在后来被确定为治疗反应者的患者样本中，与伊马替尼孵育18小时后，WT1表达和集落生长显著降低，但在未出现治疗反应的患者样本中则未降低。体外WT1表达的抑制与伊马替尼诱导的BCR-ABL酪氨酸激酶活性的抑制相关，这一发现也在涉及某些费城染色体（Ph）阳性和Ph阴性细胞系的研究中得到。
治疗前BM样本在体外短期暴露于伊马替尼后WT1转录水平的抑制与集落生长的抑制相关，可能代表一种能够预测个体CML患者对伊马替尼治疗敏感性的简易检测方法的基础。
