异鼠李素与索拉非尼联合对肾癌的抑制作用及作用机制

Anti-tumor activity and mechanisms of isorhamnetin in combination with sorafenib for renal cancer

本研究主要探讨黄芪成分异鼠李素与索拉非尼联合使用后对肾癌的生长抑制作用及其作用机制。MTT法检测异鼠李素及与索拉非尼联合后的抗肿瘤活性;采用小鼠Renca移植瘤模型观察其对肾癌生长的抑制作用。Western blot初步探讨异鼠李素及与索拉非尼联合后抗肾癌作用机制。淋巴细胞增殖实验检测体内异鼠李素及与索拉非尼联合后对小鼠脾淋巴细胞增殖影响。结果显示,异鼠李素对不同肾癌细胞增殖有较弱的抑制作用,其作用于A498细胞、786-O细胞和Renca细胞120 h后的半数抑制浓度(IC50)分别是31.7、28.8和106.0μmol·L^-1,异鼠李素联合索拉非尼可增加索拉非尼对Renca细胞的生长抑制作用,索拉非尼的IC50由26.1μmol·L^-1降至12.0μmol·L^-1;单独使用50.0 mg·kg^-1异鼠李素能较弱地抑制小鼠Renca肾癌的生长,抑制率仅为26.9%,而此剂量的异鼠李素和20.0 mg·kg-1索拉非尼联合使用时抑制率可达60.7%,提示异鼠李素可增加索拉非尼的抗肾癌活性。Western blot结果表明,异鼠李素可通过抑制c-Raf/MEK/ERK、AKT/mTOR等信号通路发挥抑制肾癌生长的作用。与对照组相比,异鼠李素与索拉非尼体内联合后能促进未活化的脾淋巴细胞增殖及刀豆蛋白A和脂多糖刺激后的淋巴细胞增殖。综上所述,异鼠李素与索拉非尼联合可增强索拉非尼的抗肾癌活性,其作用机制可能与抑制c-Raf/MEK/ERK和AKT/mTOR信号通路有关。动物实验中对动物的处理均遵循中国医学科学院药物研究所动物实验中心标准操作规程。

This study aimed to explore the anti-tumor activity and mechanisms of action of isorhamnetin, a compound isolated from Astragalus membranaceus, in combination with sorafenib for treatment of renal cell carcinoma(RCC). The anti-tumor activity of isorhamnetin in combination with sorafenib was detected by MTT assay with cells in culture or Renca xenograft model in mice. Western blot was used to study the mechanisms of isorhamnetin in combination with sorafenib. Lymphocyte proliferation assay was also used to investigate the effects of the two drugs in combination. The results indicated that isorhamnetin inhibited the proliferation of RCC cells, with IC50 for A498, 786-O and Renca cell lines with being 31.7, 28.8 and 106.0 μmol·L^-1, respectively.Isorhamnetin in combination with sorafenib improved the anti-lymphocyte proliferation activity of sorafenib with the IC50 down to 12.0 μmol · L^-1. Isorhamnetin inhibited the growth of RCC in mice slightly with the inhibition efficiency at 26.9%. With 50.0 mg·kg^-1 isorhamnetin in combination with 20.0 mg·kg^-1 sorafenib, the anti-tumor activity of sorafenib was enhanced, with inhibition of growth rate increased to 60.7%. Meanwhile, isorhamnetin in combination with sorafenib could promote the lymphocytes proliferation in Renca xenograft model. Western blot results showed that combination of isorhamnetin and sorafenib could inhibit c-Raf/MEK/ERK and AKT/mTOR signaling pathways. In conclusion, the combination of isorhamnetin with sorafenib could increase the anti-tumor activity of sorafenib in RCC in vitro and in vivo. The mechanisms may be related to the inhibition of c-Raf/MEK/ERK and AKT/mTOR signaling pathways. Procedures for animal study were performed with approval of the Animal Care and Use Committee of the Chinese Academy of Medical Sciences and Peking Union Medical College.