SFBR联合贝伐珠单抗对结肠癌脉管系统的影响

目的 探讨单次近距离放疗（SFBR）联合贝伐珠单抗对结肠癌脉管系统的影响。方法 复制小鼠结肠癌移植瘤模型，随机分为空白对照组、SFBR组、贝伐珠单抗组、SFBR联合贝伐珠单抗组（以下简称联合组）。治疗结束后第14天计算移植瘤的终体积和肿瘤生长抑制率。运用¹⁸F-FDG micro PET/CT测量肿瘤最大标准摄取值（SUV_max），评估肿瘤代谢活性。采用免疫组织化学法检测肿瘤组织的微血管密度（MVD）、淋巴管密度（LVD）、血管生成拟态密度（VMD）及肿瘤细胞Ki-67阳性表达率。利用流式细胞学技术检测肿瘤细胞凋亡率，评估肿瘤凋亡情况。结果 联合组肿瘤组织中MVD、LVD、VMD低于SFBR组和贝伐珠单抗组（P <0.05），SUV_max、Ki-67表达水平低于SFBR组和贝伐珠单抗组（P <0.05）；而联合组肿瘤抑制率、肿瘤细胞凋亡率高于SFBR组和贝伐珠单抗组（P <0.05）。结论 SFBR联合贝伐珠单抗能降低结肠癌组织中MVD、LVD、VMD，从而有效抑制结肠癌的生长。

Effects of SFBR combined with bevacizumab on the vasculature of colon cancer

Objective To investigate the influence of Single-Fraction Brachytherapy (SFBR) combined with bevacizumab on the vasculature of colon cancer.Methods The colon cancer model mice were randomly divided into control group, SFBR group, bevacizumab group and SFBR combined bevacizumab group (united group). On the 14th day after the end of treatment, The tumor volume of mice in each group and tumor growth inhibition rate (TGIR) of treatment groups were calculated. The tumor metabolism was assessed by micro 18F-FDG PET-CT imaging. The Immunohistochemistry method was used to detect the expression of microvessel density (MVD), lymphatic vessel density (LVD), vasculogenic mimicry density (VMD) and the expression of Ki-67 in tumor tissues of the mice in each group. The apoptotic rate of cancer cells was detected by flow cytometry.Results The MVD, LVD and VMD in the united group were lower than those in the SFBR group and bevacizumab group (P < 0.05), maximum standard uptake value (SUVmax ) and and the expression of Ki-67 in the united group was lower than that in the SFBR group and bevacizumab group (P < 0.05), Whie the TGIR and the apoptotic rate of united group was higher when Compared with those in the SFBR group and bevacizumab group (P < 0.05).Conclusion SFBR combined with bevacizumab can reduce MVD, LVD and VMD in colon cancer tissue and inhibit the growth of colon cancer effectively.