接合物蛋白磷酸化水平在伊马替尼治疗慢性粒细胞白血病中的临床意义

目的 探讨接合物蛋白(CRKL)的磷酸化水平在伊马替尼治疗慢性粒细胞白血病(CML)中的临床意义.方法 分别采用筑巢式PCR扩增ABL激酶区序列、实时荧光定量PCR法、流式细胞术检测35例CML患者不同时期52份骨髓标本ABL激酶区点突变、BCR-ABL基因转录水平、CRKL磷酸化水平,分析CRKL磷酸化水平与前两者的关系.结果 15例伊马替尼耐药患者中6例(40.0%)检测到ABL激酶区点突变,涉及四种类型氨基酸的改变,分别为Y253H 1例、E255K 1例、T315I 3例、F317L 1例,其中2例(T315I、Y253H)处于急变期,3例(E255K、T315I、F317L)处于加速期,1例(T315I)处于慢性期.初诊组BCR-ABL mRNA水平高于伊马替尼治疗有效组(P=0.01);伊马替尼耐药组BCR-ABL mRNA水平高于伊马替尼治疗有效组(P=0.03);伊马替尼耐药组BCR-ABLmRNA水平与初诊组差异无统计学意义(P=0.18).伊马替尼耐药组与初诊组磷酸化CRKL阳性细胞百分率及平均荧光强度(MFI)均明显升高,两组差异无统计学意义(P=5.130;P=3.178);但初诊组较伊马替尼治疗有效组患者显著增高(P=0.000;P=0.01),伊马替尼耐药组较伊马替尼治疗有效组患者显著增高(P=0.000;P=0.02);磷酸化CRKL阳性细胞百分率、MFI与BCR-ABL mRNA表达水平存在正相关关系(P＜0.05).结论 应用流式细胞术检测P210BCR-ABL主要底物CRKL蛋白的磷酸化水平,是快速便捷的检测CML患者酪氨酸激酶活性的方法,CRKL磷酸化水平可作为评价伊马替尼治疗CML的疗效指标.

Abstract：

Objective To investigate the adaptor protein CRKL phosphorylation level( p-CRKL) and its significance in chronic myeloid leukemia(CML) treated with imatinib. Methods ABL kinase domain was amplified by nested RT-PCR, domain point mutations analysis by direct sequencing, BCR-ABL mRNA level by real time-PCR, and p-CRKL level by flow cytometry in 52 bone marrow samples from 35 CML patients,and the relationship of p-CRKL level with ABL kinase domain mutation and with BCR-ABL mRNA level was analyzed. Results In the 15 imatinib-resistant patients, ABL domain point mutations were detected in 6 with 4 types of nucleotide substitutions: T315I ( n = 3 ), Y253 H ( n = 1 ), E255 K and F317 L. The incidence of mutations in disease chronic phase ( CP), accelerated phase (AP) and blast phase (BP) was 25.00%,40.00% and 30.00%, respectively. The BCR-ABL mRNA level in newly diagnosed CML was higher than that in imatinib-responded patients (P =0.01 );and so did in imatinib-resistant patients than in imatinib-effective patients ( P = 0. 03 ). The level of BCR-ABL mRNA was not significantly different between newly diagnosed CML and imatinib-resistant patients. p-CRKL%, MFI showed a high degree of phosphorylation in newly diagnosed CML and imatinib-resistant patients(P = 5.130; P = 3.178 ). The level of p-CRKL % and MFI in newly diagnosed group was higher than that in imatinib responded group( P = 0.000; P = 0.01 ) and also higher in imatinib-effective group than in imatinib-resistant group (P = 0. 000; P = 0. 02 ). There was apositive correlation between the level of BCR-ABL expression and p-CRKL % ( and the MFI of p-CRKL)( P ＜ 0. 05 ). Conclusion It seems that p-CRKL detection might be helpful in predicting imatinib treatment outcomes.

Clinical significance of CRKL protein phosphorylation level in the treatment of chronic myeloid leukemia with imatinib

Objective To investigate the adaptor protein CRKL phosphorylation level( p-CRKL) and its significance in chronic myeloid leukemia(CML) treated with imatinib. Methods ABL kinase domain was amplified by nested RT-PCR, domain point mutations analysis by direct sequencing, BCR-ABL mRNA level by real time-PCR, and p-CRKL level by flow cytometry in 52 bone marrow samples from 35 CML patients,and the relationship of p-CRKL level with ABL kinase domain mutation and with BCR-ABL mRNA level was analyzed. Results In the 15 imatinib-resistant patients, ABL domain point mutations were detected in 6 with 4 types of nucleotide substitutions: T315I ( n = 3 ), Y253 H ( n = 1 ), E255 K and F317 L. The incidence of mutations in disease chronic phase ( CP), accelerated phase (AP) and blast phase (BP) was 25.00%,40.00% and 30.00%, respectively. The BCR-ABL mRNA level in newly diagnosed CML was higher than that in imatinib-responded patients (P =0.01 );and so did in imatinib-resistant patients than in imatinib-effective patients ( P = 0. 03 ). The level of BCR-ABL mRNA was not significantly different between newly diagnosed CML and imatinib-resistant patients. p-CRKL%, MFI showed a high degree of phosphorylation in newly diagnosed CML and imatinib-resistant patients(P = 5.130; P = 3.178 ). The level of p-CRKL % and MFI in newly diagnosed group was higher than that in imatinib responded group( P = 0.000; P = 0.01 ) and also higher in imatinib-effective group than in imatinib-resistant group (P = 0. 000; P = 0. 02 ). There was apositive correlation between the level of BCR-ABL expression and p-CRKL % ( and the MFI of p-CRKL)( P ＜ 0. 05 ). Conclusion It seems that p-CRKL detection might be helpful in predicting imatinib treatment outcomes.