Antitumor Activities and Apoptosis-regulated Mechanisms of Fermented Wheat Germ Extract in the Transplantation Tumor Model of Human HT-29 Cells in Nude Mice

Objective A subcutaneous transplantation tumor model of human HT-29 cells in nude mice was established to evaluate anticarcinogenic activities, and the apoptosis-regulated mechanism effect of aqueous extract of fermented wheat germ with Lactobacillus plantarum dy-1 （LFWGE）. Methods The HT-29 cells were transplanted via subcutaneous injection of 1×10^7cells into the right flank of each nude mouse. Then, nude mice were treated for 30 d with LFWGE （high-dose 2 g/kg/d; low-dose 1 g/kg/d） and for 7 d with 5-fluorouracil （5-FU, 25 mg/kg/d） by gavage and intraperitoneal injection, respectively. An inhibition of tumor growth was observed. Results Tumor volume and weights decreased significantly in both groups of nude mice treated with LFWGE. In addition, the cell apoptosis rate of the LFWGE group （2 g/kg/d, 60.2%＋4.4%; 1 g/kg/d, 58.6%＋6.9%） was significantly higher than that of the control group （11.5%＋1.6%） and 5-FU group （32.1%＋3.5%） as measured by the TUNEL assay. Moreover, the real-time fluorescent quantitative PCR and Western blot method further confirmed these enhancing apoptosis and growth inhibition effects. The involvement of LFWGE in inducing apoptosis was confirmed by the expression of Bax, Bcl-2, Caspase-3, and CyclinD1. Conclusion The results showed that LFWGE could induce subcutaneous transplantation tumor apoptosis in nude mice and could be as a natural nutrient supplements or chemopreventive agent in the treatment of human colon cancer.

Antitumor Activities and Apoptosis-regulated Mechanisms of Fermented Barley Extract in the Transplantation Tumor Model of Human HT-29 Cells in Nude Mice

Objective A subcutaneous transplantation tumor model of human HT-29 cells was established in nude mice to study the anticarcinogenic activities and apoptosis-regulatory mechanistic effect of aqueous extract of fermented barley with Lactobacillus plantarum dy-1 （LFBE）. Methods HT-29 cells were transplanted via subcutaneous injection of 1 × 107cells into the right flank of each nude mouse. Then, nude mice were treated for 30 days with LFBE （high-dose 2 g·kg-1·d-1; low-dose 1 g·kg-1·d-1） and for 7 days with 5-fluorouracil （5-FU, 25 g·kg-1·d-1） by gavage and intraperitoneal injection, respectively. Results Tumor volume and weight decreased significantly in both groups of nude mice treated with LFBE. In addition, the cell apoptosis rate of the LFBE group was significantly higher than that of the control group and 5-FU groups as measured by the TUNEL assay. Moreover, the real-time fluorescent quantitative PCR and Western blot methods further confirmed these apoptosis-enhancing and growth-inhibiting effects. The involvement of LFBE in inducing apoptosis was confirmed by the expression of Bax, Bcl-2, caspase-3, and cyclin D1. Conclusion The results showed that LFBE could induce subcutaneous transplantation tumor apoptosis in nude mice and could be used as a natural nutrient supplement or chemopreventive agent in the treatment of human colon cancer.

异叶败酱总苷片对人大肠癌HT-29细胞凋亡的影响

目的:研究异叶败酱总苷片对人大肠癌细胞凋亡的影响及作用机制。方法:建立人大肠癌HT-29裸鼠移植瘤模型,设立异叶败酱总苷片低、中、高剂量组和空白组、5-氟脲嘧啶(5-FU)+甲酰四氢叶酸钙(CF)对照组,给药8周后处死裸鼠,瘤体称重,末端原位标记染色法(TUEL)检测凋亡指数,分别行半胱天冬氨酸蛋白酶-3(caspase-3)、Bax和Bcl-2免疫组化染色,图象分析系统定量检测并比较该3种物质表达情况。结果:异叶败酱总苷片各组瘤重小于空白对照组,而凋亡指数均高于空白对照组和5-FU+CF组,其中高剂量组与空白对照组和5-FU+CF组比较差异有极显著性(P<0.01)。异叶败酱总苷片各组移植瘤caspase-3表达及Bax、Bcl-2表达的相对比率(Bax/Bcl-2)均高于空白对照组。结论:异叶败酱总苷片具有诱导人大肠癌HT-29裸鼠移植瘤细胞凋亡的作用,其机制可能与促进移植瘤caspase-3表达及增大Bax/Bcl-2表达比率有关。

Two sides to colon cancer: mice mimic human anatomical region disparity in colon cancer development and progression

Aim:Strong evidence reveals important differences between cancers in the proximal vs.distal colon.Animal models of metastatic colon cancer are available but with varying degrees of reproducibility and several important limitations.We explored whether there were regional differences in the location of murine colon cancers and assessed the utility of murine models to explore the biological basis for such differences.Methods:We re-analyzed data from our previous studies to assess the regional distribution of murine colon cancer.In survival surgery experiments,we injected HT-29 human colon cancer cells into the wall of the cecum or distal colon of Nu(NCr)-Foxn1 nu or NOD.Cg-Prkdc scid Il2rg Tim1Wji/SzJ mice and compared the development of primary tumors and metastases.Results:Within 7-17 weeks after intramural cecal injection of HT-29 cells,eight mice failed to develop solid primary tumors or metastases.In contrast,within four weeks after cell injection into the distal colon,13 mice developed metastases-12 mice developed subcutaneous metastases;of these,four developed liver metastases and one developed both liver and lung metastases.One mouse developed liver metastases only.Histological examination confirmed these lesions were adenocarcinomas.Conclusion:Our findings reveal the preferential growth of murine colon neoplasia and invasive human orthotopic xenografts in the distal mouse colon.The new approach of injecting cells into the distal colon wall results in a pattern of colon cancer development that closely mimics the progression of metastatic colon cancer in humans.This novel model of colon neoplasia has great potential for exploring anatomical differences in colon cancer and testing novel therapeutics.