慢性髓系白血病STI571耐药与蛋白酪氨酸磷酸酶活性关系

目的探索蛋白酪氨酸磷酸酶(PTP)家族部分成员参与慢性髓系白血病(CML)STI571的耐药机制。方法利用cDNA表达谱芯片技术初步筛选耐药细胞K562/G01与K562/W差异表达基因,应用半定量RT-PCR技术验证芯片结果;进一步检测耐药细胞系K562/G01及STI571耐药的CML患者单个核细胞胞浆蛋白PTP活性,了解PTP与耐药的相关性。结果耐药细胞K562/G01基因表达谱芯片分析发现:其中1个PTP成员出现表达下调PTPRF(PPFIA4)基因,Ratio0.413,GenbankID:NM-015053],1个PTK成员表达升高(PTK9基因Ratio2.004,GenebankID:NM-198974)。胞浆蛋白PTP活性检测:K562/G01细胞胞浆蛋白PTP活性(126.45pmol/min·μg)较K562/W活性(137.32pmol/min·μg)降低;CML耐药组患者骨髓单个核细胞胞浆蛋白PTP活性为(124.83±12.14)pmol/min·μg较非耐药组患者(138.75±13.29)pmol/min·μg也降低(P=0.04)。结论PTP家族部分成员参与了STI571的耐药机制,PTP活性降低提示患者临床出现STI571耐药倾向。

Relationship of PTP activity and resistance to STI571 in chronic myeloid leukemia

Objective To study the correlation between mechanisms of STI571-resistance and expression of protein-tyrosine-phosphatase(PTP) member in chronic myeloid leukemia and K562-R.Methods An expression profile cDNA microarray, BioStarH40s, was used to dectect the potential differential expression genes of PTP members. And the results were validated by semi-quantitative RT-PCR technique. Furthermore, the total PTP activity of tumor cells from CML(chronic myelogenous leukemia) patients and of K562/G01 were detected with the Tyrosine Phosphatase Assay System.Results Further analysis of an expression profile cDNA microarray found one PTP's member, PTPRF(PPFIA4), down-regulated and one PTK's member up-regulated. Furthermore, The PTP activity of K562/G01 (126.45pmol/min·μg) was lower than that of k562/W (137.32 pmol/min·μg). And the same phenomenon was found in the mononuclear cells of STI571 resistant CML cells and non-resistant cells. Conclusion The mechanisms of STI571-resistance involved the expression of PTP member in chronic myeloid leukemia resistant.