慢性髓系白血病细胞中SphK-1/S1P信号通路的初步研究

SphK-1/S1P Signal Pathway in CML Cells

慢性髓系白血病(CML)是一种以髓系细胞受累为主的多能造血干细胞的克隆性疾病。为探讨SphK-1/S1P信号通路元件在CML细胞中的表达情况,研究P210bcr/abl是否涉及到SphK-1/S1P信号通路,首先采用RT-PCR检测bcr/abl阳性的K562细胞和bcr/abl阳性的原代CML细胞中SphK-1和S1P受体mRNA的表达。进一步利用P210bcr/abl特异抑制剂甲磺酸伊马替尼处理bcr/abl阳性的K562细胞和CML原代细胞,然后通过32P-ATP掺入法测定细胞内SphK-1的酶活性。结果表明:K562细胞经2.5μmol/L甲磺酸伊马替尼处理0.5、2、6、24和48小时后,对SphK-1活性抑制强度分别为0.007%、38.9%、34.6%、28.1%和76.1%;CML原代细胞在使用2.5μmol/L甲磺酸伊马替尼处理后SphK-1活性较对照下降(16.8-41.9)%。结论:CML细胞中存在SphK-1和S1P的表达,P210bcr/abl具有激活SphK-1的作用。

Chronic myelogenous leukemia （CML） is a clonal myeloproliferative disease of transformed hematopoietic progenitor cells. In order to investigate the role of sphingosine ldnase-1 （SphK-1）/sphingosine 1-phosphate （S1P） signal pathway in the expression of CML cells, and to explore whether P210^bcr/abll involved is activating SphK-1/S1P signal pathwey, the expressions of SphK-1 and S1P receptor mRNA in bcr/abl positive K562 cells and bcr/abl positive primary CML cells were detected by RT-PCR, the imatinib mesylate, the specific inhibitor of P210^bcr/abl was employed to inhibit the P210^bcr/abl tyrosine kinases of K562 cells and CML primary cells, and then the intracellular SphK-1 activity was assayed. The results indicated that after being cultured with 2. 5 μmol/L imatinib mesylate for 0.5, 2, 6, 24 and 48 hours, the intensions of inhibiting SphK-1 activity were 0. 007%, 38.9%, 34. 6%, 28. 1% and 76. 1% resepectively. SphK-1 activity in CML cells also was reduced by 2.5 μmol/L imatinib mesylate （ 16.8% - 41.9% decrease）. It is concluded that the CML cells express SphK-1 and different S1P receptor, and P210^bcr/abl fusion protein in CML cells can activate SphK-1.