芥菜子对DMH诱导大鼠大肠癌预防作用的体内研究

目的:探讨芥菜籽(MS)对1,2-二甲基肼(DMH)诱导的大鼠大肠癌的预防作用.方法:用DMH腹腔注射诱导大鼠发生大肠癌,观察MS对诱癌率及胸腺指数和脾指数等的影响.结果:用DMH成功诱导大鼠大肠癌模型,正常对照组未见肿瘤发生,DMH组腺癌发生率为83.33％ (10/12),腺瘤发生率为16.67％(2/12),总肿瘤发生率为100％(12/12),肝及淋巴结转移率为58.33％(7/12).5％MS和7.5％MS组腺癌发生率比DMH组分别降低了58.33％和75.00％(X2=15.662,P=0.000),肝及淋巴结转移率分别降低了41.66％和50.00％(x2 =8.585,P=0.014),总肿瘤发生率[66.67％(8/12),41.70％(5/12)]亦显著低于DMH组(x2=9.687,P=0.008),而腺瘤发生率[41.67％(5/12),33.33％(4/12)]则高于DMH组.7.5％MS组大鼠胸腺指数和睥指数均明显大于DMH组,P值分别为0.013和0.037;同时5％MS组胸腺指数也显著大于DMH组,P=0.039.结论:MS对DMH诱导的大肠癌有预防发生及减少转移的作用,并能改善机体免疫功能.     

儿茶素抑制二甲基肼诱发小鼠大肠癌的实验研究

昆明小鼠随机分成7组,1-5组小鼠皮下注射DMH,剂量20mg/kg体重,每周1次,连续20wk.第2-5组于注射前1wk开始灌胃儿茶素1mg、2mg、4mg、EGCG 2mg/每只/每日,第6组给几茶素3mg作为对照组,每周连续灌胃5次至23wk.第7组为溶剂对照组,27wk处死小鼠.结果显示:2组对照小鼠未发生肿瘤,DMH组大肠层发生率为80％,与第2-5组比较明显升高(P<0.0001),当同时用不同剂量儿茶素后,DMH诱发大肠癌的例数、瘤结数和肿瘤体积、累及肠周径     

人参皂甙Rg3对实验性小鼠大肠肿瘤的预防作用

目的:研究人参皂甙Rg3对二甲肼(DMH)诱导的小鼠大肠肿瘤的预防作用及机制。方法:以DMH诱导小鼠大肠肿瘤,诱癌第8周起予以不同浓度Rg3,观察Rg3对大肠肿瘤的化学预防作用;免疫组化方法检测Rg3对小鼠肠肿瘤MVD的影响以及Rg3对VEGF蛋白的表达影响。结果:相比于阳性对照组,不同浓度Rg3能够减少小鼠大肠癌发生率40%～50%,P<0.05;平均荷瘤数减少50%～60%,P<0.05;腺癌百分率减少30%～40%,P<0.05。相比于对照组(17.71±6.08),Rg3能够明显减少实验组小鼠肿瘤组织中的MVD(9.74±4.22),P<0.05。Rg3能够抑制小鼠肠肿瘤组织中VEGF蛋白的表达,P<0.05。结论:Rg3能够抑制DMH诱导的小鼠大肠肿瘤的发生,这种预防作用同Rg3对VEGF和MVD的抑制作用有关。     

芥菜籽调节机体免疫系统预防实验性大鼠大肠癌的机制

目的 研究芥菜籽（mustard seed,MS）对淋巴细胞的过继免疫,验证其免疫调节作用,并初步探讨免疫预防机制。方法 48只5周龄的雄性Wistar大鼠,随机分为4组,每组12只。用l,2-二甲基肼(DMH)腹腔注射诱导大鼠大肠癌模型,分离大鼠脾脏淋巴细胞过继免疫对大鼠进行回输,32周实验结束时,观察记录各组大鼠有无肿瘤发生及发生数目和肿瘤大小,计算肿瘤发生率,肿瘤胸腺指数和脾指数,并观察脾细胞的CD4+T细胞和CD8+T细胞的表达情况。结果 DMH成功诱导大鼠大肠癌模型,正常对照组未见肿瘤发生,二甲基肼(DMH)组,肿瘤发生率为91.7%。淋巴细胞回输组和7.5%MS组肿瘤发生率比DMH组分别降低了40%、50%, MS干预组及淋巴细胞回输组胸腺指数和脾指数均明显大于DMH组（P<0.05）,并且CD4+T细胞与CD8+T细胞比值降低（P<0.05）。结论 芥菜籽可以调节机体免疫系统,通过增强机体免疫力预防DMH诱导大肠癌的发生。     

叶酸对二甲肼诱发小鼠大肠癌干预及其机制的研究

目的:观察在二甲肼(dimethylhydrazine,DMH)诱导小鼠大肠癌的过程中,通过叶酸进行化学干预能否预防肿瘤的发生.方法:以DMH诱发ICR小鼠大肠癌,在诱癌过程中用叶酸进行干预,观察其对肿瘤发生率的影响.定量PCR检测癌基因c-myc转录水平.甲基化特异性PCR(MSP)分析癌基因c-myc启动子区甲基化情况.结果:补充叶酸使小鼠大肠癌的发生率由95%降低至45%;MSP分析9例c-myc表达升高的DMH造模组中有4例发现肿瘤组织DNA启动子区低甲基化,并且发现这4只小鼠的叶酸水平为(71.65±7.04) ng/mL,低于该组其他小鼠(85.75±11.78) ng/mL,P<0.05.结论:通过补充叶酸能有效降低DMH诱发小鼠大肠癌的发生率,其预防肿瘤发生的作用机制与其对基因表达的表观遗传调控有关.     

植酸和魔芋干预二甲肼诱发ICR小鼠大肠癌的初步研究

饮食与大肠癌的关系极为密切,植酸(PA)和魔芋(KM)均为天然食物。本实验表明在二甲肼诱发ICR 小鼠大肠癌过程中,2%PA 饮水25周能使肿瘤发生率和浸润性生长发生率分别从100.0%和70.0%下降至42.9%14.3%;5～10%KM 饲料喂饲25周能使肿瘤发生率从100.0%下降至50.0%,但未能观察到 PA 和 KM协同抑癌作用。PA 和 KM 也能显著地减轻与肿瘤密切有关的超氧化物歧化酶、丙二醛等生化指标的变化程度。     

芥菜籽通过抗氧化和免疫偏移预防大肠肿瘤的实验研究

背景与目的：近年来有关十字花科植物预防肿瘤的研究,主要探讨其抗氧化、抗突变作用、调节免疫功能及诱导细胞凋亡等。芥菜籽(mustard seeds,MS)是十字花科植物的种子。本研究旨在探讨MS对1,2-二甲基肼(1,2-dimethylhydrazine,DMH)诱导的大鼠大肠肿瘤的抗氧化和免疫偏移作用机制。方法：将48只Wistar雄性大鼠随机均分为4组：DMH模型组(模型组)、DMH+5%MS干预组(5%MS干预组)、DMH+7.5%MS干预组(7.5%MS干预组)和正常对照组。模型组和MS干预组每周按30 mg/kg剂量给予DMH腹腔注射1次,连续20周,均于32周时处死大鼠观察大肠肿瘤发生率并HE染色确定肿瘤的组织分型,检测血清脂质过氧化产物丙二醛(malondialdehyde,MDA)水平、抗氧化酶活力、Th1和Th2亚群细胞因子含量。结果：正常对照组大鼠无肿瘤发生。模型组总成瘤率为100%,5%MS干预组和7.5%MS干预组总成瘤率分别降低33.3%和58.3%(P<0.05)。DMH诱导大鼠形成肿瘤的过程中,模型组MDA水平和Th2亚群细胞因子含量均显著高于正常对照组(P<0.05);而抗氧化酶活力明显低于正常对照组(P<0.05)。经MS干预后MDA呈显著下降趋势(P<0.05),而抗氧化酶活力和Th1亚群细胞因子含量均呈显著升高趋势(P<0.05)。结论：芥菜籽显著降低DMH化学诱导的大鼠大肠肿瘤的发生,作用机制可能与其抗氧化作用和免疫平衡偏移有关。     

蚕豆根尖细胞微核试验——经二甲基肼处理小鼠的粪便诱变及抗诱变效应

一般认为膳食对大肠癌发生起重要作用。据推测膳食成分为底物由肠道菌从代谢活动,而产生内源性致癌物。Ames试验发现西方饮食居民的粪便提取物有诱变性,大肠癌高发人群粪便诱变性检测阳性率显著高于低发人群。我们用二甲基肼(DMH)诱发昆明种小鼠大肠癌,在27周末处死动物,发现饲以发酵奶动物大肠癌的发生率显著低于DMH组及牛奶组,且肿瘤数亦低。本研究应用蚕豆根尖细胞微核试验检测各组小鼠     

血管生成抑制剂YH-16抑制结肠癌肝转移的研究

背景与目的:YH-16是新合成的重组人血管内皮抑制素,Ⅱ期临床试验已证实YH-16联合化疗治疗晚期非小细胞肺癌具有协同作用。本文探讨血管生成抑制剂YH-16对结肠癌肝转移的抑制作用。方法:MTT法测定血管生成抑制剂YH-16对血管内皮细胞和结肠癌CT26细胞的IC50;经小鼠脾脏下极包膜下注入CT26细胞建立结肠癌肝转移模型,60只小鼠随机分为对照组、低剂量YH-16组、中剂量YH-16组、高剂量YH-16组,YH-16剂量分别为0mg/kg、0.40mg/kg、0.75mg/kg和1.50mg/kg,术后2周观察各组小鼠肝转移情况,采用免疫组化方法检测肝转移瘤组织中血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)的表达和肿瘤微血管密度(microvesseldensity,MVD)。结果:(1)YH-16对结肠癌CT26细胞和血管内皮细胞的IC50分别为(2.16±0.28)μg/ml和(0.64±0.10)μg/ml,前者是后者的3.38倍;(2)对照组,低、中、高剂量YH-16组肝转移率分别为100.0%、92.3%、80.0%和73.3%。高剂量YH-16组肝转移瘤数目明显低于对照组、低剂量YH-16组和中剂量YH-16组(P值均<0.05);(3)对照组,低、中、高剂量YH-16组脾脏肿瘤体积的中位数分别为1.180cm3、1.201cm3、0.887cm3和0.781cm3,四组比较无显著性差异(P>0.05);(4)YH-16各剂量组肝转移瘤组织中VEGF的表达较对照组无明显降低,四组肝转移瘤的MVD分别为65.00±9.58、58.15±8.81、51.60±7.10和44.53±11.47,中、高剂量YH-16组的MVD计数较对照组明显降低,高剂量YH-16组MVD计数较中剂量和低剂量YH-16组明显降低(P值均<0.05)。结论:血管生成抑制剂YH-16可以明显抑制结肠癌肝转移。     

烟曲霉醇联合环磷酰胺对小鼠LA795肺腺癌转移的抑制作用

背景与目的:血管生成抑制剂联合化疗药物治疗肿瘤成为目前研究热点之一。本研究旨在观察烟曲霉醇(fumagillol,TNP-470)联合环磷酰胺(cyclophosphamide,CTX)对肺腺癌小鼠异体移植转移的协同抑制作用,并初步探讨TNP-470抑制肿瘤转移的相关机制。方法:将40只接种高转移性LA795肺腺癌细胞的T739裸小鼠随机分成5组:对照组、溶剂组、TNP-470组(30mg/kg)、CTX组(40mg/kg)、联合组(TNP-47030mg/kg CTX40mg/kg)。实验3周后,处死全部小鼠。剥离皮下肿瘤称瘤重并计算抑瘤率;取出双肺观察表面肿瘤转移情况,计算肿瘤肺转移发生率,计数各组小鼠肺表面转移结节数及计算出肺表面结节转移抑制率。免疫组化和图像分析系统检测皮下移植瘤中微血管密度(microvesseldensity,MVD)、P-选择素表达并定量分析。结果:联合组抑瘤率(81.5%)明显高于其他各组(P<0.01),Q值等于1.21,说明两药合用具有协同作用。与对照组(12.13±4.02)相比,联合组(1.75±1.71)、TNP-470组(4.75±3.34)、CTX组(8.50±2.67)肺表面转移结节数明显下降;同时TNP-470组和联合用药组皮下肿瘤内MVD、P-选择素表达与对照组相比均下降,差异有显著性(P<0.01),而CTX组对此则无明显影响。结论:TNP-470与CTX对LA795肺腺癌的肺结节转移具有协同抑制作用;TNP-470抑制LA795肺腺癌转移与其抑制肿瘤内P-选择素表达有关。     

结直肠癌肝转移的多因素分析

目的 探讨结直肠癌肝转移的相关因素。方法 收集结直肠癌病例1312例,建立数据库。选择性别,年龄,血型,病程,首发症状,肿瘤大小,组织类型,肠壁侵袭,淋巴结转移等临床因素。用Logistic回归（spss10.0统计软件）进行单因素和多因素分析。并对有意义的指标进行相关分析。结果 单因素分析显示,性别,病程,肿瘤大体类型,组织类型,病理分级,肠壁侵袭和淋巴结转移与肝转移有关。多因素分析显示,仅性别,肠壁侵袭和淋巴结转移与肝转移有关。结直肠癌肝转移男女性别比为1.9:1。肝转移发生与肿瘤侵袭肠壁的层次呈正相关（r=0.926,P=0.024)。肝转移发生与淋巴结转移距离的远近无关（r=0.748,P=0.252)。结论 结直肠癌肝转移的相关因素主要有性别,肿瘤侵袭深度和淋巴结转移,男性结直肠癌患者更易发生肝转移,肿瘤侵袭肠壁越深,发生肝转移的危险越大,年龄,血型,病程,首发症状,肿瘤部位,肿瘤大小,术前合并症,并发病与肝转移无关。     

塞来昔布对实验性结肠癌原位移植瘤生长及血管形成的影响

目的:探讨塞来昔布对实验性结肠癌原位移植瘤生长及血管形成的影响。方法:使用对数生长期的人结肠癌细胞(HT-29)于裸鼠皮下接种成瘤后原位种植。术后随机分为对照组(C组)及塞来昔布高、中、低剂量组(H、M、L组)共四组进行研究。结果:24只裸鼠实验期间无1只死亡,成瘤率为100%,比较各组原位移植瘤体积和瘤质量差异有统计学意义,P值均<0·05。L、M和H组的抑瘤率分别为25·30%、38·80%和76·92%,与对照组比较差异有统计学意义,P=0·000,且存在明显的剂量依赖。干预组瘤组织中MVD、VEGFmRNA、MMP-2mRNA和匀浆上清中PGE2含量与对照组相比差异有统计学意义,P值分别为0·050、0·050、0·050和0·010,随着剂量增加,MVD、VEGFmRNA、MMP-2mRNA和匀浆上清中PGE2含量逐渐降低。瘤组织中PGE2含量与瘤质量,以及MVD与VEGFmRNA、MMP-2mRNA均存在显著的正相关性,r=0·8814,P=0·000;r=0·8573,P=0·000;r=0·6427,P=0·001。结论:塞来昔布通过抑制人结肠癌裸鼠原位移植瘤环氧化酶-2活性,抑制PGE2合成、VEGFmRNA和MMP-2mRNA表达,抑制肿瘤的血管形成,从而对结肠癌的生长有抑制作用。     

低剂量131I标记的抗癌胚抗原抗体C50联合5-FU对结直肠癌裸鼠移植瘤生长的影响

背景与目的:癌胚抗原 (CEA)在结直肠癌组织中表达率高达 90%以上,本研究拟探讨低剂量 131I标记的抗 CEA单抗 C50( 131I- C50)及低剂量 131I- C50联合 5-氟尿嘧啶( 5- FU)对人结直肠癌移植瘤生长的影响.方法:建立表达 CEA的人 LoVo结直肠癌裸鼠移植瘤模型.接种第 9天,分别采用 5- FU、2775kBq 131I- C50及 5- FU联合 131I- C50尾静脉注射治疗荷瘤裸鼠.尾静脉给药后第 7天,每组各随机处死 2只荷瘤裸鼠,观察肿瘤细胞超微结构改变及组织病理学改变.计算各组裸鼠肿瘤体积、群体倍增时间及抑瘤率,比较接种第 30天的肿瘤体积.结果:对照组、5- FU组、131I- C50治疗组和 131I- C50联合 5- FU组接种第 30天肿瘤体积分别为 (9 765.19± 792.21)mm3、(6 533.75± 601.14)mm3、(5 413.57± 415.46)mm3和 (3 865.23± 263.57)mm3,四组之间差异均有显著性( P< 0.001);四组肿瘤群体倍增时间依次延长,分别为 3.07、3.09、3.18和 3.14天;后三组抑瘤率依次增大,分别为 30.97%、42.33%和 59.04%.结论:低剂量 131I- C50可抑制结直肠癌裸鼠移植瘤的生长,低剂量 131I- C50联合 5- FU可以增强抑制肿瘤生长的效果.     

Augmentation of 1,2-dimethylhydrazine-induced colon cancer by experimental colitis in mice: role of dietary vitamin E

Because ulcerative colitis predisposes to colonic cancer, for determination of the effect of colitis on experimental colon carcinogenesis, rectal instillations of peptides that attract and activate neutrophils were used to induce colitis in CD-1 (ICR) BR mice receiving 20 weekly injections of the carcinogen 1,2-dimethylhydrazine [(DMH) CAS: 540-73-8]. From week 4 through week 15 of DMH injections, twice-weekly enemas of formyl-norleucyl-leucyl-phenylalanine were given to DMH-treated mice. The effect of the antioxidant vitamin E in the diet (1,750 IU/kg diet) was studied in another group of mice treated with DMH and having colitis. Four weeks after DMH was discontinued, cancer occurred in 9 of 28 (32%) animals with DMH plus control enemas, in 22 of 29 (76%) animals with DMH plus colitis (P = .001), and in 16 of 28 (57%) animals with DMH plus colitis plus supplemental vitamin E (P = .11 compared with the group with DMH and colitis). Colitis enhances DMH-induced colonic carcinogenesis.     

Rapid induction of colorectal tumors in rats initiated with 1,2-dimethylhydrazine followed by dextran sodium sulfate treatment

To establish a rapid bioassay system with neoplastic end-points for detection of colorectal carcinogenesis modifiers, we evaluated the effects of dextran sodium sulfate (DSS) treatment on the different stages of carcinogenesis in rats initiated with 1,2-dimethylhydrazine (DMH). F344 male rats were given three subcutaneous injections of DMH (40 mg/kg body weight) in a week, and were administered drinking water containing 1.0% DSS ad libitum either during or after the initiation period for a week, or both during and after initiation periods for 2 weeks. At the 10th week of the experiment, although the numbers of aberrant crypt foci were significantly decreased in all groups treated with DSS and given DMH-initiation as compared with DMH alone, dysplastic foci/adenomas/adenocarcinomas were increased. The incidences and multiplicities of these lesions were highest in rats treated with DSS after DMH-initiation period. At the 26th week, the incidences of adenocarcinomas (100 vs. 20% in DMH alone) and their multiplicities (6.6 +/- 0.8/rat vs. 0.2 +/- 0.4/rat in DMH alone) were also highest in this group. These results indicate that short-term DSS-treatment in the post-initiation period significantly accelerates DMH-induced colorectal tumor development in rats, so that this protocol may effective for establishment of a rapid bioassay system with neoplastic end-points.     

Carcinogenicity of 1,2-DimethyIhydrazine in Colorectal Tissue Heterotopically Transplanted into the Glandular Stomach of Rats

The present study was designed to examine the effect of the intestinal carcinogen 1,2-dimethyl-hydrazine (DMH) on grafted colorectal mucosa implanted into the glandular stomach of rats. Four groups were studied: Group 1 received the operation and DMH, Group 2 received the operation alone, Group 3 received DMH alone and Group 4 (controls) received only a sham operation. For Groups 1 and 2, about 8-mm diameter segments of colorectal tissue obtained from various sites in the large intestine of 8-week-old male F344 rats were isologously implanted into the fundic region of the stomachs of age-matched rats. DMH was injected at a dose of 20 mg/kg body weight i.m. per week for 20 weeks beginning 4 weeks after the operation. The animals were then observed for 8 months after the initial DMH treatment. In Group 1, adenocarcinomas developed in 41 of 60 successful implants (68%). Furthermore, poorly differentiated type tumors were observed in the grafts obtained from the rectum. This finding was contrary to that for intrinsic rectal tumors, all of which were well differentiated. The histochemical staining of mucin in the tissues from different sites of the large intestine revealed that sulfomucin, which normally exists essentially only in the intrinsic descending colon or rectum, was present in the grafts from the proximal ascending or ascending colon. No gastric tumors were observed in the control rats, which received either DMH or sham operations alone. Tumors in the intrinsic large intestine were observed only in rats that received DMH. These results indicate that colorectal mucosa implanted into the glandular stomach, like the intrinsic large intestine, is still sensitive to tumorigenesis caused by DMH.     

The Effects of Phyllanthus niruri Linn on Infiltrating Dendritic Cell and Ratio of Neutrophile/Lymphocytes in Chemotherapy of Sprague-Dawley Rats with Colorectal Cancer

Background: Chemotherapy as part of colorectal cancer management can cause death to immunologically active tumor cell, but also it has immune suppressive effect. Phyllanthus niruri Linn is known to has immunomodulatory effect. This study was intended to prove P. niruri Linn effect on infiltrating dendritic cells and Neutrophil/lymphocyte ratios (NLRs) in Sprague–Dawley rats with colorectal cancer which were given capecitabine chemotherapy. Methods: The study was randomized post–test only control group design. The samples were 39 Sprague–Dawley male rats, with body weight around 170–220 grams, induced by 1,2-dimetylhydrazine (DMH) 30 mg/kgBW once per week subcutaneously. On 9th,11th and 13th week, there were four induced rats sacrificed each week to detect colorectal cancer (CRC) development. On the 13th week, all of the 4 sacrificed rats developed colon cancer, so the induction had to be stopped. The rest of 27 induced rats were randomly divided into three groups: control-group (K) were left untreated (9 rats), group P1 (9 rats) were given Capecitabine and group P2 (9 rats) were given Capecitabine with combination of P. niruri Linn extract 13.5 mg/kgBW orally. After 17th week, all rats were terminated and tumor lesion of colon were processed to be paraffin blocks and were stained with HE for evaluating the NLRs, and immunohistochemistry (S100) for evaluating infiltrating dendritic cells. Data was analyzed by using Oneway-Anova-test and post-Hoc LSD-test. Considered significant if p was <0.05. Results: The mean±standard deviation of infiltrating dendritic cells showed increasing value in group P2 (62.11±31.35) compared to group P1 (52.78±29.24) though not statistically significant. The mean of NLRs also showed statistically significant elevation of value in group P2 (0.13±0.05) compared to group P1 (0.04±0.01). Conclusion: Extract of Phyllanthus niruri Linn increasing immunologic status through elevation of infiltrating dendritic cells and NLRs in animal model colorectal cancer with Capecitabine chemotherapy.