下调AP-1基因表达在冬凌草甲素抑制结直肠癌中的作用  

Downregulation of AP-I gene expression is an initial event in oridonin-mediated inhibition of colorectal cancer

作　　者：金黑鹰[1] 戴功建[2] 丁义江[1] 夏建国[2] 刘秀芳[1] 刘飞[1] 谈瑄忠[1] 耿建祥[1] 

机构地区：[1]南京中医药大学第三附属医院肛肠医疗中心,210001 [2]江苏省人民医院胃肠外科

出　　处：《中华实验外科杂志》2011年第1期22-26,共5页Chinese Journal of Experimental Surgery

基　　金：国家自然科学基金资助项目（30572447、30973837）;江苏省自然科学基金资助项目（BK2007009）

摘　　要：目的探讨冬凌草甲素对结直肠癌的抑制作用及其机制。方法以冬凌草甲素水溶液处理LoVo和SW480结直肠癌细胞株，噻唑蓝（MTT）比色法检测细胞增殖抑制率，以Illumina表达芯片检测LoVo细胞和SW480细胞基因表达的变化，对变异的基因进行定量逆转录一聚合酶链反应（RT—PCR）检测，建立结肠造口的结肠癌原位移植模型，以冬凌草甲素水溶液对动物模型进行腹腔注射，观察肿瘤的增殖并对上述发现的相关变化基因进行RT—PCR检测。结果冬凌草甲素在25mg／L剂量即对LoVo细胞和SW480细胞产生80％以上的抑制率，而且随药物剂量升高和时间延长，抑制率呈逐渐上升趋势；经冬凌草甲素处理后基因表达发现在LoVo结直肠癌中冬凌草甲素可以明显促进CKS2、SFN、SERTAD1、HERC5、RECQL4、GADD45AQ、bax、bxl-2等基因的表达，明显抑制了AP-1、NFkb和p38；而在SW480结直肠癌中冬凌草甲素可以促进ABCG1、ERCC1、HERC5、TERF2IP和TERF2IP等基因表达；与对照组比较，应用冬凌草甲素处理后的结肠癌结肠造口原位移植模型肿瘤生长速度明显低于对照组（P〈0．01），而SW480结直肠癌和LoVo结直肠癌在冬凌草甲素处理后肿瘤的生长速度差异无统计学意义（P〉0．05）。在肿瘤模型中仅仅发现AP-1基因表达下调，其余的基因均无上调或下调，在4周时定量RT-PCR检测发现，不仅AP-1基因下调，而且核因子（NF）-κB和p38明显下调。结论冬凌草甲素体外和体内研究都能明显抑制结直肠癌肿瘤的增殖，而且对2种肿瘤细胞株抑制率差异无统计学意义；在体外研究中发现冬凌草甲素可能抑制多种基因的信号转导途径，但是在在体研究中，只发现AP-1、NF-κB和P38下调，而且AP-1基因下调出现要早于其他2个基因，提示AP-1基因的下调可能是冬凌草甲素抑制结直肠癌的早期事件，AP-1抑制可能影响了NF-κB和MAKP途径基�Objective Ooridonin is the activeingredient isolated from the Chinese herb Rabdosia rubescens. We used both in vivo and in vitro approaches to elucidate the underlying mechanism of the oridonin-mediated inhibition of colorectal cancer. Methods Two colorectal cell lines, LoVo and SW480, were treated with oridonin in solution. The effect of this treatment on inhibition of cell proliferation rate was determined by the methyl thiazol tetrazolium （MTT） method. The changes in gene expression that occurred in both cell lines in response to treatment with oridonin were determined via illumine expression sensor. Additionally, a colorectal cancer colostomy implantation model was established. Animals were injected intraperitoneally with an oridonin solution. Results Treatment of LoVo and SW480 cells with oridonin in- hibited cell proliferation in a dose-dependent manner. The inhibition rate was increased with prolonged treatment. The growth rate of the colorectal cancer colostomy implantation model was significantly lower than control cells when treated with oridonin （P 〈 0. 01 ）. However, oridonin treatment did not have a significant effect on tumor growth rate （P 〉 0. 05）. In the tumor model, AP-1 was the only gene found to be downregnlated after oridonin treatment by the gene expression sensor. After 4 weeks of treatment, AP-1, nuclear factor-KB （NF-KB） and p38 were all found to be downregulated. Conclusion Our study has confirmed the inhibitory effects of oridonin on colorectal cancer. These results indicate that the downregulation of AP-1 might be an initial response to treatment by oridonin. This regulation could, in turn, affect the expression of the NF-κB and MAPK pathways, thereby inhibiting tumor growth.

关 键 词：冬凌草甲素 结直肠癌 AP-1 

分 类 号：R735.3[医药卫生—肿瘤]