不同转移潜能人神经母细胞瘤细胞系趋化因子受体CXCR4的表达及对瘤细胞趋化作用的影响

The expression of functional chemokine receptor CXCR4 is associated with the metastatic potential of human neuroblastoma

目的以自建的人神经母细胞瘤转移瘤（QDDQ-NM2）及原位瘤（QDDQ-NM2）细胞系的细胞为研究对象，探讨CXCR4在不同转移潜能人神经母细胞瘤细胞系细胞中的表达情况及其对瘤细胞趋化作用的影响。方法采用RT-PCR检测两神经母细胞瘤细胞系细胞CXCR4mRNA的表达；流式细胞仪直接免疫荧光法检测两细胞系细胞膜表面CXCR4蛋白的表达；通过趋化和趋化抑制实验观察CXCR4特异性配体CXCLl2对QDDQ-NM1和QDDQ-NM2细胞系瘤细胞的趋化作用。结果RT-PCR显示QDDQ-NM，细胞系CXCR4mRNA的相对含量为0．57±0．08，QDDQ-NM2细胞系为0．29±0．05，两者比较差异有统计学意义（P=0．005〈0．05），流式细胞仪直接免疫荧光法检测两细胞系细胞膜表面CXCR4蛋白表达的阳性率分别为（64．59±1．57）％和（36．72±0．57）％，两者的差异有统计学意义（P=0．00〈0．05），CXCR4特异性配体CXCLl2可在一定范围内呈浓度依赖性的趋化QDDQ-NM1和QDDQ-NM2细胞系细胞的迁移，以100ng／ml的效果较为明显，两细胞系迁移到聚碳酸酯膜下的细胞数差异有统计学意义（P〈0．05）。CXCR4特异性拮抗剂AMD3100能有效抑制这种趋化作用（P〈0．05）。结论QDDQ-NM1细胞系的细胞功能性高表达趋化因子受体CXCR4,可能与人神经母细胞瘤QDDQ-NM1细胞系细胞的体外高转移潜能有关。

Objective To study the expression of functional chemokine receptor CXCR4 and its effects on the metastatic potential of human neuroblastoma. Methods Two human neuroblastoma cell lines were used in this study, including QDDQ-NM1 with high metastatic potential and QDDQ-NM2 with low metastatic potential. The expression of CXCR4 was explored at mRNA level using RT-PCR, and the protein level by flow cytometry. Chemotaxis assay was also performed to study the migratory response of QDDQ-NM1 and QDDQ-NM2 to CXCR4 ligand CXCL12. Results The mRNA of CXCR4 was higher in QDDQ-NM1 group than that in QDDQ-NM2 group （0. 57 ± 0. 08 vs 0. 29 ± 0. 05, P = 0. 005）. The expression of CXCR4 on QDDQ-NM1 group was also higher than that in QDDQNM2 group [（64. 59± 1.57）% vs （36. 72±0. 57）%0, P〈0. 05]. The QDDQ-NM1 cells exhibited stronger migratory response to CXCL12 in a concentration dependent manner （P〈0. 05）, and the response peaked to CXCL12 at 100 ng/ml. AMD3100, a specific CXCR4 antagonist, could reverse the tumor＇s migratory response to CXCL12. Conclusions The expression of CXCR4 is associated with the metastatic potential of human neuroblastoma.