基质细胞衍生因子-1/CXCR4轴介导非霍奇金淋巴瘤肿瘤浸润的实验研究

The role of stromal cell derived factor-1/CXCR4 biological axis in tumor metastasis of non-Hodgkin lymphoma

目的探讨基质细胞衍生因子-1(SDF-1)及其受体 CXCR4在非霍奇金淋巴瘤(NHL)中的表达及其与 NHL 肿瘤浸润的关系。方法采用逆转录聚合酶链反应(RT-PCR)方法检测淋巴结和骨髓基质细胞中 SDF-1α的表达,采用流式细胞术检测淋巴结和骨髓中淋巴瘤细胞 CXCR4受体的表达,并采用 Transwell 微孔隔离室实验检测淋巴瘤细胞在体外向重组人 SDF-1α(rhSDF-1α)的趋化反应。结果侵犯骨髓的 NHL 患者骨髓淋巴瘤细胞和未侵犯骨髓的 NHL 患者骨髓单个核细胞表面CXCR4受体的表达均明显高于正常骨髓(84.10±12.12,72.76±8.73和33.20±7.73,P<0.01),而NHL 患者来源于淋巴结的淋巴瘤细胞 CXCR4的表达亦显著高于反应性增生淋巴结炎患者(101.04+21.89 vs 34.81±9.90,P<0.01)。此外,被淋巴瘤侵犯的骨髓基质细胞高表达 SDF-1α,而未被淋巴瘤侵犯的骨髓及正常骨髓基质细胞表达 SDF-1α低下,二者比较差异有统计学意义(P<0.01);且 NHL 患者淋巴结基质细胞 SDF-1α的表达高于反应性增生淋巴结炎患者(P<0.01)。趋化实验发现三种不同来源的 NHL 患者淋巴结和骨髓的单个核细胞均能向 rhSDF-1α发生趋化反应,且抗 CXCR4单抗可明显抑制上述细胞的迁移。结论 SDF-1/CXCR4生物学轴是介导 NHL 肿瘤侵袭的重要机制,CXCR4在淋巴瘤细胞表面以及 SDF-1在淋巴瘤转移部位的同时高表达与 NHL 瘤细胞的转移和浸润密切相关。

Objective To study the expression of stromal cell derived factor-1 （ SDF-1 ） and its receptor CXCR4 in non-Hodgkin lymphoma （NHL）, and to investigate the role of this biological axis in tumor metastasis of NHL. Methods Specimens of bone marrow were collected from 4 patients with NHL with bone marrow infiltration and 4 cases of NHL without bone marrow infiltration, and 4 patients with benign hematopathy with normal myologram. Lymphoma specimens were collected from 7 cases of NHL and 3 cases of reactive proliferative lymphadenitis. The level of SDF-1α mRNA in the stromal cells of bone marrow and lymph node were determined by RT-PCR. The CXCR4 expression on lympboma cells freshly isolated from bone marrow and lymph node of the NHL patients were studied by flow cytometry. Transwell assay was performed, the upper chamher being added with suspension of cells newly isolated from lymph nodes or bone marrow undergoing co-incubation with ant-CXCR4 monoclonal antibody or not, and the lower chamber added with culture fluid with or without recombinant human SDF-1α （rhSDF-lct）. The migration rate of the primary lymphoma cells towards rhSDF-1α was calculated. Results The expression levels of CXCR4 on the lymphoma cells isolated from the bone marrow involved or not involved by NHL were both significantly higher than that of the mononuclear cells from normal bone marrow （ both P 〈 0. 01 ）, whereas the CXCR4 expression level on the lymphoma cells from the lymph nodes of the NHL patients was also significantly higher than that of the mononuclear cells from the lymph nodes of reactive proliferative lymphadenitis （ P 〈 0.01 ）. The SDF-lct mRNA expression level/n the stromal cells isolated from the bone marrow involved by NHL was significantly higher than those of the stromal cells of bone marrow not involved by NHL and the normal bone marrow （both P 〈0.01 ）. Moreover, the SDF-1α expression level in the lymph node stromal cells of all the NHL patients was also significantly higher than that of the patients with reactive proliferative lymphadenitis （P 〈0. 01 ）. Transwell assay revealed that all three kinds of primary lymphoma cells migrated towards rhSDF-1α effectively,and this migration was markedly inhibited by the addition of anti-CXCR4 monoclonal antibody to the lymphoma cells（all P〈0.01）.Conclusion SDF-1/CXCR4 axis plays a uniquely important biological role in mediating tumor metastasis of NHL.