苹果多糖预防小鼠结肠炎癌变的作用及其机制研究
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摘要
目的研究苹果多糖对小鼠结肠炎癌变的预防作用,并探讨其作用机制。方法从苹果渣中提取苹果多糖,使用致炎剂葡聚糖硫酸钠(DSS)和致癌剂氧化偶氮甲烷(AOM),建立小鼠结肠炎相关结直肠癌动物模型。通过免疫组织化学、蛋白质印迹法、酶联免疫分析等方法观察苹果多糖预防用药对各组小鼠血清中促炎细胞因子肿瘤坏死因子(TNF)-α以及组织TLR4/My D88/NF-κB p65通路的影响。结果苹果多糖预防用药20周后,与模型组(95%致癌率)相比,苹果多糖(1.25%、2.5%和5%)将结直肠肿瘤的发生率降至26%、10%、5%。蛋白质印迹法结果显示,苹果多糖各个剂量组均降低结直肠组织中TLR4、My D88和NF-κB p65蛋白表达。酶联免疫分析结果显示,苹果多糖各剂量组小鼠血清中肿瘤坏死因子-α水平明显降低(P<0.05)。结论苹果多糖可有效预防结肠炎癌变,其作用机制可能与其抑制TLR4/My D88/NF-κB通路有关。
OBJECTIVE To study the effects and mechanisms of apple polysaccharides( AP) on tumorigenesis in a mouse model of colitis-associated colon cancer. METHODS AP was obtained from apple pomace and its protective efficacy was evaluated on carcinogenesis in a mouse model of colitis-associated colon cancer induced by azoxymethane( AOM) and dextran sodium sulfate( DSS).The effects of AP on TLR4 / My D88 / NF-κB pathway were measured using immunohistochemistry,ELISA and Western blot. The serum were collected and TNF-α was measured by ELISA kits. RESULTS After 20 weeks of continuous treatment,the incidence of colon cancer formation was 95% in the mice treated with AOM / DSS( model group),and these reduced to 26%,10% and 5% in AP( 1. 25%,2. 5% and 5%) treatment group respectively. Western blot analysis demonstrated that TLR4( membrane protein),My D88,NF-κB p65( nuclear protein) expression decreased significantly at protein level; and the secretion of TNF-α decreased in control group( P < 0. 05). CONCLUSION AP could protect ICR mice from CACC effectively and the possible mechanism may be related to the inhibition of TLR4 / My D88 / NF-κB pathways.
OBJECTIVE To study the effects and mechanisms of apple polysaccharides( AP) on tumorigenesis in a mouse model of colitis-associated colon cancer. METHODS AP was obtained from apple pomace and its protective efficacy was evaluated on carcinogenesis in a mouse model of colitis-associated colon cancer induced by azoxymethane( AOM) and dextran sodium sulfate( DSS).The effects of AP on TLR4 / My D88 / NF-κB pathway were measured using immunohistochemistry,ELISA and Western blot. The serum were collected and TNF-α was measured by ELISA kits. RESULTS After 20 weeks of continuous treatment,the incidence of colon cancer formation was 95% in the mice treated with AOM / DSS( model group),and these reduced to 26%,10% and 5% in AP( 1. 25%,2. 5% and 5%) treatment group respectively. Western blot analysis demonstrated that TLR4( membrane protein),My D88,NF-κB p65( nuclear protein) expression decreased significantly at protein level; and the secretion of TNF-α decreased in control group( P < 0. 05). CONCLUSION AP could protect ICR mice from CACC effectively and the possible mechanism may be related to the inhibition of TLR4 / My D88 / NF-κB pathways.
引文
[1]MISALE S,YAEGER R,HOBOR S,et al.Emergence of KRAS mutations and acquired resistance to anti-EGFR therapy in colorectal cancer[J].Nature,2012,486(7404):532-536.
[2]AVIELLO G,CORR S C,JOHNSTON D G,et al.My D88 Adaptor-like(Mal)regulates intestinal homeostasis and colitis-associated colorectal cancer in mice[J].Am J Physiol Gastrointest Liver Physiol,2014,306(9):769-778.
[3]JAGANATHAN S K,VELLAYAPPAN M V,NARASIMHAN G,et al.Role of pomegranate and citrus fruit juices in colon cancer prevention[J].World J Gastroenterol,2014,20(16):4618-4625.
[4]GROSSO G,BIONDI A,GALVANO F,et al.Factors associated with colorectal cancer in the context of the mediterranean diet:A case-control study[J].Nutr Cancer,2014,66(4):558-565.
[5]LI Y,LIU L,NIU Y,et al.Modified apple polysaccharide prevents against tumorigenesis in a mouse model of colitis-associated colon cancer:Role of galectin-3 and apoptosis in cancer prevention[J].Eur J Nutr,2012,51(1):107-117.
[6]LI Y,NIU Y,MEI Q,et al.Modified apple polysaccharides could induce apoptosis in colorectal cancer cells[J].J Food Sci,2010,75(8):224-229.
[7]TANAKA T,KOHNO H,SUZUKI R,et al.A novel inflammation-related mouse colon carcinogenesis model induced by azoxymethane and dextran sodium sulfate[J].Cancer Sci,2003,94(11):965-973.
[8]FUKATA M,CHEN A,KLEPPER A,et al.Cox-2 is regulated by Toll-like receptor-4(TLR4)signaling:Role in proliferation and apoptosis in the intestine[J].Gastroenterology,2006,131(3):862-877.
[9]LI Y,LIU L,NIU Y,et al.Modified apple polysaccharide prevents against tumorigenesis in a mouse model of colitis-associated colon cancer:Role of galectin-3 and apoptosis in cancer prevention[J].Eur J Nutr,2012,51(1):107-117.
[10]NIELSEN O H,JESS T,BJERRUM J T,et al.Ulcerative colitis[J].Ugeskr Laeger,2013,175(20):1412-1416.
[11]VIENNOIS E,CHEN F,MERLIN D.NF-κB Pathway in colitisassociated cancers[J].Transl Gastrointest Cancer,2013,2(1):21-29.
[12]SZUMILAS D,KRYSIAK R,OKOPIEB.The role of TLR4 receptor in development of inflammation and carcinogenesis in ulcerative colitis and pharmacotherapy of this disorder[J].Wiad Lek,2013,66(1):3-9.
[13]SLATTERY M L,HERRICK J S,BONDURANT K L,et al.Tolllike receptor genes and their association with colon and rectal cancer development and prognosis[J].Int J Cancer,2012,130(12):2974-2980.
[14]CAO H,XU Z,LONG H,et al.The-765C allele of the cyclooxygenase-2 gene as a potential risk factor of colorectal cancer:A meta-analysis[J].Tohoku J Exp Med,2010,222(1):15-21.
[15]UMESALMA S,SUDHANDIRAN G.Differential inhibitory effects of the polyphenol ellagic acid on inflammatory mediators NF-kappa B,i NOS,COX-2,TNF-alpha,and IL-6 in 1,2-dimethylhydrazine-induced rat colon carcinogenesis[J].Basic Clin Pharmacol Toxicol,2010,107(2):650-655.
[2]AVIELLO G,CORR S C,JOHNSTON D G,et al.My D88 Adaptor-like(Mal)regulates intestinal homeostasis and colitis-associated colorectal cancer in mice[J].Am J Physiol Gastrointest Liver Physiol,2014,306(9):769-778.
[3]JAGANATHAN S K,VELLAYAPPAN M V,NARASIMHAN G,et al.Role of pomegranate and citrus fruit juices in colon cancer prevention[J].World J Gastroenterol,2014,20(16):4618-4625.
[4]GROSSO G,BIONDI A,GALVANO F,et al.Factors associated with colorectal cancer in the context of the mediterranean diet:A case-control study[J].Nutr Cancer,2014,66(4):558-565.
[5]LI Y,LIU L,NIU Y,et al.Modified apple polysaccharide prevents against tumorigenesis in a mouse model of colitis-associated colon cancer:Role of galectin-3 and apoptosis in cancer prevention[J].Eur J Nutr,2012,51(1):107-117.
[6]LI Y,NIU Y,MEI Q,et al.Modified apple polysaccharides could induce apoptosis in colorectal cancer cells[J].J Food Sci,2010,75(8):224-229.
[7]TANAKA T,KOHNO H,SUZUKI R,et al.A novel inflammation-related mouse colon carcinogenesis model induced by azoxymethane and dextran sodium sulfate[J].Cancer Sci,2003,94(11):965-973.
[8]FUKATA M,CHEN A,KLEPPER A,et al.Cox-2 is regulated by Toll-like receptor-4(TLR4)signaling:Role in proliferation and apoptosis in the intestine[J].Gastroenterology,2006,131(3):862-877.
[9]LI Y,LIU L,NIU Y,et al.Modified apple polysaccharide prevents against tumorigenesis in a mouse model of colitis-associated colon cancer:Role of galectin-3 and apoptosis in cancer prevention[J].Eur J Nutr,2012,51(1):107-117.
[10]NIELSEN O H,JESS T,BJERRUM J T,et al.Ulcerative colitis[J].Ugeskr Laeger,2013,175(20):1412-1416.
[11]VIENNOIS E,CHEN F,MERLIN D.NF-κB Pathway in colitisassociated cancers[J].Transl Gastrointest Cancer,2013,2(1):21-29.
[12]SZUMILAS D,KRYSIAK R,OKOPIEB.The role of TLR4 receptor in development of inflammation and carcinogenesis in ulcerative colitis and pharmacotherapy of this disorder[J].Wiad Lek,2013,66(1):3-9.
[13]SLATTERY M L,HERRICK J S,BONDURANT K L,et al.Tolllike receptor genes and their association with colon and rectal cancer development and prognosis[J].Int J Cancer,2012,130(12):2974-2980.
[14]CAO H,XU Z,LONG H,et al.The-765C allele of the cyclooxygenase-2 gene as a potential risk factor of colorectal cancer:A meta-analysis[J].Tohoku J Exp Med,2010,222(1):15-21.
[15]UMESALMA S,SUDHANDIRAN G.Differential inhibitory effects of the polyphenol ellagic acid on inflammatory mediators NF-kappa B,i NOS,COX-2,TNF-alpha,and IL-6 in 1,2-dimethylhydrazine-induced rat colon carcinogenesis[J].Basic Clin Pharmacol Toxicol,2010,107(2):650-655.