Department of Orthopaedics, Warren Alpert Medical School of Brown University and Rhode Island Hospital, Coro West Building, 1 Hoppin St, Providence, RI 02903, USA.
Mol Cancer Ther. 2013 Jul;12(7):1163-70. doi: 10.1158/1535-7163.MCT-12-1092. Epub 2013 May 17.
Chondrosarcoma is notable for its lack of response to conventional cytotoxic chemotherapy, propensity for developing lung metastases, and poor survival. Therefore, a better understanding of angiogenic and metastatic pathways is needed. Multiple pathways regulate angiogenesis and metastasis, including chemokines and their receptors. In this study, we investigated chemokine (C-X-C motif) receptor 4 (CXCR4) signaling in chondrosarcoma and tested the hypotheses that CXCR4 inhibition suppresses tumor angiogenesis and metastasis. CXCR4 expression, analyzed by real-time PCR and Western blot, was increased in human chondrosarcoma cell line JJ compared with normal chondrocytes and was further increased in JJ by hypoxia (2% O2), vascular endothelial growth factor A (VEGFA; 10 ng/mL), and in xenograft tumors in nude mice. The CXCR4 ligand CXCL12 (10 ng/mL) doubled secreted VEGFA, measured with ELISA, under hypoxic conditions and this conditioned media increased human umbilical vein endothelial cell tube formation. These effects were inhibited by CXCR4 siRNA or AMD3100 (5 μg/mL). In a xenograft mouse model, four weeks of AMD3100 treatment (1.25 mg/kg, intraperitoneally twice daily) inhibited tumor angiogenesis, tumor growth, and metastasis. VEGFA content in tumor extracts was decreased (7.19 ± 0.52 ng/mL control vs. 3.96 ± 0.66 treatment) and bioimaging of angiogenesis was decreased by 56%. Tumor volumes averaged 4.44 ± 0.68 cm(3) in control compared with 2.48 ± 0.61 cm(3) in the treatment group. The number of lung metastatic nodules was 23 ± 9 in control compared with 10 ± 6 in the treatment group (N = 8/group). Therefore, CXCR4-targeted therapy may be a treatment strategy for chondrosarcoma.
软骨肉瘤的特点是对常规细胞毒化疗无反应、易发生肺转移和预后不良。因此,需要更好地了解血管生成和转移途径。多种途径调节血管生成和转移,包括趋化因子及其受体。在这项研究中,我们研究了软骨肉瘤中的趋化因子(C-X-C 基序)受体 4(CXCR4)信号,并测试了以下假设:CXCR4 抑制可抑制肿瘤血管生成和转移。通过实时 PCR 和 Western blot 分析,与正常软骨细胞相比,人软骨肉瘤细胞系 JJ 中 CXCR4 的表达增加,在缺氧(2%O2)、血管内皮生长因子 A(VEGFA;10ng/mL)和裸鼠异种移植肿瘤中进一步增加。在缺氧条件下,CXCL12(10ng/mL)使 ELISA 测量的分泌型 VEGFA 增加一倍,并且该条件培养基增加了人脐静脉内皮细胞管形成。这些作用可被 CXCR4 siRNA 或 AMD3100(5μg/mL)抑制。在异种移植小鼠模型中,AMD3100 治疗 4 周(1.25mg/kg,腹腔内每日两次)抑制肿瘤血管生成、肿瘤生长和转移。肿瘤提取物中的 VEGFA 含量降低(对照组 7.19±0.52ng/mL,治疗组 3.96±0.66ng/mL),血管生成生物成像降低 56%。对照组肿瘤体积平均为 4.44±0.68cm3,治疗组为 2.48±0.61cm3(每组 N=8)。因此,CXCR4 靶向治疗可能是软骨肉瘤的一种治疗策略。