Department of Oncology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China.
J Radiat Res. 2011;52(1):1-8. doi: 10.1269/jrr.10013. Epub 2010 Dec 24.
The aims of present study were to evaluate the efficacy of combining sunitinib with ionizing radiation (IR) on endothelial cells in vitro and in vivo. Human umbilical vein endothelial cells (HUVECs) were exposed to IR with or without sunitinib pretreatment. Apoptosis assay and cell cycle distribution were analyzed by flow cytometry. Clonogenic survival assay at 3 Gy dose with or without sunitinib was performed. The activity of phosphatidylinositol 3-kinase (PI3K)/Akt signal pathway was detected by Western immunoblot. Lewis lung carcinoma mouse model was built to examine the effect of combination therapy on endothelial cells in vivo. Microvasculature changes were detected by immunohistochemistry using anti-CD31 antibody. Our results showed combination therapy of sunitinib and IR significantly increased apoptosis of endothelial cells and inhibited colony formation compared to sunitinib or radiotherapy alone. It also resulted in cell cycle redistribution (decreasing cells in S phase and increasing cells in G2/M phase). The activity of PI3K/Akt signal pathway was inhibited, which could be the potential mechanisms that account for the enhanced radiation response induced by sunitinib. In vivo analysis showed that combination therapy significantly decreased microvasculature formation. The results demonstrated that combination therapy of sunitinib and IR has the potential to increase the cytotoxic effects on endothelial cells.
本研究旨在评估舒尼替尼联合电离辐射（IR）对体外和体内血管内皮细胞的疗效。将人脐静脉内皮细胞（HUVEC）用或不用舒尼替尼预处理后进行 IR 照射。采用流式细胞术分析细胞凋亡和细胞周期分布。用或不用舒尼替尼进行 3Gy 剂量的集落形成存活试验。采用 Western 免疫印迹检测磷脂酰肌醇 3-激酶（PI3K）/Akt 信号通路的活性。建立 Lewis 肺癌小鼠模型，检测体内联合治疗对血管内皮细胞的影响。用抗 CD31 抗体通过免疫组织化学检测微血管变化。我们的结果表明，与舒尼替尼或放疗单独治疗相比，舒尼替尼联合 IR 治疗显著增加了内皮细胞的凋亡并抑制了集落形成。它还导致细胞周期重新分布（减少 S 期细胞，增加 G2/M 期细胞）。PI3K/Akt 信号通路的活性受到抑制，这可能是舒尼替尼诱导辐射反应增强的潜在机制。体内分析表明，联合治疗显著减少了微血管形成。结果表明，舒尼替尼联合 IR 治疗有可能增加对内皮细胞的细胞毒性作用。
