姜黄素体内外逆转结肠癌的5-氟尿嘧啶耐药研究及机制探讨

目的 探究姜黄素在体内外对结肠癌5-氟尿嘧啶（5-fluorouracil，5-FU）耐药的逆转作用及其相关机制。方法 以SW480结肠癌细胞为亲代细胞，构建5-FU耐药细胞株SW480R，采用MTT法检测SW480R细胞的耐药指数以及不同浓度的姜黄素对SW480R细胞增殖能力的影响；流式细胞术检测姜黄素对SW480R细胞周期和凋亡的影响；Western blotting检测姜黄素对SW480R细胞上皮-间充质转化（epithelial-mesenchymal transition，EMT）相关蛋白以及Wnt信号通路相关蛋白的影响；采用裸鼠移植瘤模型检测肿瘤体积变化情况，计算姜黄素的体内抑瘤率，Western blotting检测肿瘤组织中相关蛋白变化。结果 SW480R的耐药指数为12.16，姜黄素能够剂量依赖性地抑制SW480R细胞的增殖，阻滞SW480R细胞周期于G₀/G₁期，以及诱导SW480R细胞凋亡；Western blotting结果表明姜黄素能够在体内外抑制EMT和Wnt信号通路的活性；体内试验表明姜黄素能够有效抑制裸鼠移植瘤的生长。结论 姜黄素能够在体内外逆转结肠癌的5-FU耐药，可能是通过调控Wnt信号通路从而抑制EMT的发生。

Study on Reversal Effect of Curcumin on 5-fluorouracil Resistance in Colon Cancer in vitro and in vivo and Its Mechanism

Abstract: Objective To investigate the reversal effect of curcumin on 5-fluorouracil (5-FU) resistance in colon cancer in vivo and in vitro and its related mechanism. Methods SW480 colon cancer cells were used as parental cells to construct 5-FU resistant cell line SW480R. MTT assay was used to determine the resistance index of SW480R cells and the effect of curcumin on the proliferation of SW480R cells. The effects of curcumin on cell cycle and apoptosis of SW480R cells were determined by flow cytometry. Western blot was used to detect the effects of curcumin on EMT-related proteins and Wnt signaling proteins in SW480R cells. The tumor volume changes were detected by using the xenograft model of nude mice, the tumor-inhibiting rate of curcumin was calculated, and the changes of related proteins in tumor tissues were detected by Western blot. Results The resistance index of SW480R was 12.16. Curcumin could dose-dependently inhibit proliferation, arrest cell cycle in G0/G1 phase, and induce apoptosis of SW480R cells. Western blot results showed that curcumin inhibited EMT and Wnt signaling activity in vivo and in vitro.In vivo experiments showed that curcumin could effectively inhibit the growth of transplanted tumor in nude mice. Conclusion Curcumin could reverse 5-FU resistance in colon cancer in vivo and in vitro, possibly by regulating the Wnt signaling pathway to inhibit EMT.