Jiang Li-Cai, Luo Jian-Min
Department of Hematology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China.
Oncol Lett. 2017 Aug;14(2):1295-1302. doi: 10.3892/ol.2017.6318. Epub 2017 Jun 6.
Patients with advanced chronic myeloid leukemia (CML) have a poor prognosis, with the use of tyrosine kinase inhibitors (TKIs) to treat CML demonstrating poor results. The results of the present study revealed that, following Cell Counting Kit-8 analysis, treatment of K562 cells with decitabine (DAC) combined with TKIs exhibits synergic effects. Co-immunoprecipitation indicated that tyrosine-protein phosphatase non-receptor type 6 (SHP-1) and BCR-ABL fusion protein (BCR-ABL) (p210) form a complex in the K562 cell line, and in the primary cells derived from patients with CML. These results suggested that SHP-1 serves a role in regulating the tyrosine kinase activity of BCR-ABL (p210). In addition, SHP-1 expression increased, while BCR-ABL expression decreased in the group treated with DAC and TKIs combined group compared with the TKI monotherapy group. Treatment with imatinib (IM) demonstrated no effect on SHP-1 methylation in the K562 cell line; however, the methylation of SHP-1 was not determined in the combined IM and DAC therapy group. Treatment with DAC demonstrated the ability to activate the expression of silenced SHP-1 through demethylation, thus decreasing BCR-ABL tyrosine kinase activity, resulting in an improved therapeutic effect on CML.
晚期慢性髓性白血病(CML)患者预后较差,使用酪氨酸激酶抑制剂(TKIs)治疗CML效果不佳。本研究结果显示,经细胞计数试剂盒-8分析后,地西他滨(DAC)联合TKIs处理K562细胞具有协同作用。免疫共沉淀表明,非受体型酪氨酸蛋白磷酸酶6(SHP-1)与BCR-ABL融合蛋白(BCR-ABL)(p210)在K562细胞系以及CML患者来源的原代细胞中形成复合物。这些结果提示,SHP-1在调节BCR-ABL(p210)的酪氨酸激酶活性中发挥作用。此外,与TKI单药治疗组相比,DAC与TKIs联合治疗组中SHP-1表达增加,而BCR-ABL表达降低。伊马替尼(IM)处理对K562细胞系中SHP-1甲基化无影响;然而,IM与DAC联合治疗组中未检测SHP-1的甲基化情况。DAC处理能够通过去甲基化激活沉默的SHP-1表达,从而降低BCR-ABL酪氨酸激酶活性,对CML产生更好的治疗效果。