地鼠颊囊癌变过程中HIF-1α、iNOS的表达及意义

目的：研究口腔黏膜癌变过程中HIF-1α、iNOS的表达及意义。方法：建立金黄地鼠颊囊癌变模型,应用逆转录聚合酶链反应（RT-PCR）法测定地鼠颊囊癌变过程中HIF-1α、iNOS;mRNA的表达。结果：HIF-1α mRNA在重度异常增生组和鳞癌组出现表达,二者间表达阳性率（44％,68％）无显著性差异（P〉0．05）;其他各组均未检测到HIF-1α mRNA的表达。iNOS在异常增生组和鳞癌组异常高表达,其中轻度、中度异常增生组与鳞癌组间有显著性差异（P〈0．05）,重度异常增生组与鳞癌组间无显著性差异（P〉0．05）。结论：HIF-1α的过度表达是黏膜癌变过程中的早期行为,早于组织学上的血管形成和浸润。HIF-1α、iNOS相互协同促进口腔黏膜癌的发生与发展,检测组织中二者的表达将成为临床监测口腔黏膜癌变进展及判断预后的重要指标。     

一氧化氮在金黄地鼠颊囊粘膜癌变中的动态观察

目的:探讨金黄地鼠颊囊粘膜癌变过程中血清及组织中一氧化氮的作用,为口腔癌的预防及早期诊断寻找 一个新的检测指标。方法:用二甲基苯并萘(DMBA)诱导金黄地鼠颊囊癌变,并在诱导癌变的不同阶段检测血清 中一氧化氮的浓度及组织中iNOS的表达。结果:地鼠颊囊粘膜在由正常向鳞癌发展的过程中,血清NO浓度及组 织中iNOS的表达强度均呈上升趋势,鳞癌组血清NO浓度与正常粘膜组、单纯增生组、异常增生组相比均有显著性 差异(P<0.05);免疫组化显示,正常颊囊粘膜组织中未见iNOS阳性表达,鳞癌中iNOS的表达较单纯增生时显著 增强(P<0.01)。血清NO浓度与组织中iNOS的表达强度之间存在正相关关系(rB=0.590,P<0.01)。结论:一 氧化氮在口腔粘膜鳞癌的发生、发展中起着促进作用,可作为诱癌过程中的一个判断指标。     

金地鼠颊囊癌变过程中IκBα蛋白表达的研究

目的 :探讨核转录因子的抑制蛋白IκBα在金地鼠颊囊鳞癌发生过程中的表达及意义。方法 :建立金地鼠颊囊癌变的动物模型。采用SABC免疫组织化学方法 ,检测在地鼠颊囊黏膜正常上皮 (n =2 2 ) ,上皮单纯增生 (n =2 0 ) ,上皮异常增生 (n =35 ) ,鳞状细胞癌 (n =2 3)中IκBα的表达变化。结果 :各阶段均有IκBα的表达 ,但表达强度不同 ,呈现一种动态变化过程。在正常颊囊黏膜组织和上皮单纯增生组织中IκBα局限表达于基底层和棘层底部细胞的胞浆中。随着上皮异常增生的出现及异常增生程度的加重 ,IκBα表达显著下降 ,较正常组和单纯增生组有显著性差异 (P <0 .0 5 )。一旦鳞癌生成后 ,IκBα表达上调 ,明显高于上皮异常增生组 (P <0 .0 1) ,甚至超过癌变前正常水平 (P <0 .0 1)。结论 :IκBα在金地鼠颊囊癌变过程中的表达异常 ,尤其是在上皮异常增生阶段的表达水平下调 ,可能是口腔黏膜上皮癌变过程中的一个早期事件 ,且可将其作为口腔癌变监测的生物学指标之一     

Survivin基因和EphB4基因在金黄地鼠颊囊癌变过程中的mRNA表达及意义

目的：探讨survivin基因和EphB4基因表达在金黄地鼠颊囊癌变过程中的作用。方法：采用DMBA诱导金黄地鼠颊囊动态癌变的动物模型,应用逆转录聚合酶链反应（RT-PCR）技术检测survivin和EphB4在各组组织中的表达。结果：Survivin mRNA在正常组、上皮单纯增生组、上皮异常增生组和鳞癌组的阳性表达率依次增加,除正常组与上皮单纯增生组无显著性差异外（P〉0．05）,其余任两组均有显著性差异（P〈0．05）。EphB4 mRNA在以上任两组中的阳性表达率无显著性差异（P〉0．05）。结论：在转录水平,survivin的表达与口腔黏膜从正常到癌变的发生发展过程有关,而EphB4则与之无关。     

核转录因子-κB在金地鼠颊囊癌变过程中的表达研究

目的　探讨核转录因子-κB家族成员的重要亚基p65及其抑制蛋白IκBα在金地鼠颊囊鳞癌发生过程中的 表达及意义。方法　建立金地鼠颊囊癌变的动物模型,采用Western blot法检测金地鼠正常颊黏膜、上皮单纯增生 黏膜、上皮异常增生黏膜和鳞癌组织所提取的核蛋白中p65的表达差异;采用SABC免疫组织化学法检测在金地鼠 颊黏膜正常上皮、上皮单纯增生、上皮异常增生、鳞状细胞癌中IκBα的表达变化。结果　正常黏膜和上皮单纯增生 黏膜中,p65表达很弱,但普遍存在IκBα的表达,该表达多局限于黏膜基底层和棘层底部细胞的胞浆中。随着上皮 异常增生的出现,p65表达增强,与正常黏膜和单纯增生黏膜相比有统计学意义(P<0.01),而IκBα表达则显著下 降(P<0.05)。鳞癌组织中p65的表达显著高于正常黏膜和异常增生黏膜(P<0.01),IκBα的表达显著升高,明显 高于上皮异常增生黏膜(P<0.01),甚至超过正常水平(P<0.01)。结论　p65在金地鼠颊囊鳞癌发生、发展过程中 被激活。p65和IκBα在金地鼠颊囊癌变过程中的表达异常,上皮异常增生阶段p65的表达上调而IκBα的表达下调, 可能是口腔黏膜上皮癌变过程中的早期事件,可作为口腔早期癌变监测的生物学指标。     

CDK2在金黄地鼠颊囊癌变过程中的表达的研究

目的探讨CDK2在金黄地鼠颊囊黏膜从正常黏膜到单纯增生、异常增生及鳞癌的表达变化.方法采用DMBA诱导48只金黄地鼠颊囊癌变动物模型,SABC免疫组化法检测CDK2蛋白的表达.结果CDK2在异常增生上皮及鳞癌的表达与正常和单纯增生组相比明显提高(P<0.05),阳性染色等级随病理等级改变提高(P<0.05).结论CDK2参与了口腔黏膜癌前病变和鳞癌的发生与发展.     

金地鼠颊囊癌变过程中p65和IKKα表达的实验研究

目的:探讨核转录因子-κB家族成员中的一个重要亚基p65及其上游激酶IKKα在金地鼠颊囊鳞癌发生 过程中的表达及意义。方法:建立金地鼠颊囊癌变的动物模型。采用Westernblot法检测12组配对金地鼠正常颊 黏膜、上皮单纯增生、上皮异常增生和鳞癌组织所提取的核蛋白中p65的表达差异。采用SABC免疫组织化学方 法,检测各组IKKα的表达变化。结果:在正常颊黏膜和上皮单纯增生组织中,未见明显的p65蛋白质印迹带,且两 者相比无显著性差异(P>0.05);在正常颊囊黏膜中IKKα的表达几乎呈阴性,黏膜上皮的各细胞层细胞未见明显 的胞浆着色。上皮单纯增生组织染色类似正常上皮。随着上皮异常增生的出现,p65蛋白质印迹带增强,较正常组 和单纯增生组均有显著性差异(P<0.01);同时,与正常组和单纯增生组相比,IKKα的阳性着色强度增强,阳性细 胞数增加,并与异常增生程度有关(P<0.01)。在鳞癌组织中,p65蛋白质印迹带明显增强,与正常组和异常增生 组相比均有显著性差异(P<0.01);而IKKα的阳性表达进一步增加,呈广泛的强阳性表达。与正常组和异常增生 组相比差异均有显著性(P<0.01)。结论:p65在金地鼠颊囊鳞癌发生、发展过程中被激活。p65和IKKα在金地 鼠颊囊癌变过程中表达异常。     

金黄地鼠颊囊癌变过程中E-钙粘附素表达的实验研究

目的 :研究E -钙粘附素在金黄地鼠颊囊癌变过程中的表达 ,探讨E -钙粘附素与肿瘤的发生、发展之间的关系及其临床意义。方法 :采用免疫组化技术检测 2 3例金黄地鼠颊囊正常黏膜 ,2 2例上皮单纯增生 ,2 2例上皮异常增生 ,2 3例鳞癌组织中E -钙粘附素的表达。结果 :E -钙粘附素在口腔正常黏膜上皮中均匀广泛被染色 ,上皮异常增生及鳞癌中E -钙粘附素呈明显下调表达 ,且与正常黏膜相比有显著性差异 (P <0 .0 5 )。结论 :E -钙粘附素的下调表达是口腔黏膜鳞癌发生发展的早期变化 ,可作为口腔黏膜恶变潜能的重要标志物。     

灵芝三萜对口腔黏膜癌防治作用及机理的研究

目的：探讨灵芝三萜对口腔黏膜癌的防治作用及其作用机理。方法：建立金黄地鼠颊囊动态癌变模型60只,分2组：实验组（灵芝三萜组）和对照组（未服用灵芝三萜组）,每组各30只,对所取标本进行病理检验,并采用免疫组化技术检测bcl-2和survivin在两组动物模型中的表达变化。结果：病理结果显示随DMBA涂药时间的延长,两组动物模型的病变呈加重趋势（P〈0.01）,第6、9、12周实验组的病变程度明显低于对照组（P〈0.05）;从总体上看两组颊囊癌变过程中不同组织学发生情况有显著差异（P〈0.01）。Bcl-2在上皮异常增生阶段、survivin在上皮单纯增生和异常增生阶段,实验组的表达强度明显低于对照组。结论：灵芝三萜对口腔黏膜癌具有抑制作用,其作用机制可能与凋亡调节基因survivin、bcl-2的下调有关。     

诱导型一氧化氮合酶抑制剂对地鼠颊囊癌变的干预作用

目的研究一氧化氮(NO)在肿瘤发生发展过程中所起的作用,探讨一氧化氮合酶(NOS)抑制剂对地鼠颊囊粘膜癌变所起的干预作用。方法90只金黄地鼠分为实验1组(TI组)、实验2组(T2组)和空白对照组(C组),利用二甲基苯并葱(DMBA)诱导T1,T2组地鼠颊囊癌变,并在T2组给予一氧化氮合酶抑制剂I,.硝基精氨酸甲醋( L, NAME),观察T1和T2组颊囊豁膜癌变中病理改变,SABC免疫组化法检测iNOS,VEGF,珊因子动态表达,硝酸还原酶法测定NO量的变化。结果】)MBA诱导T1组和72组颊囊薪膜癌变率的差异有统计学意义,P < O.OS,iNOS, VEGF阳性表达增加,NO量和微血管密度不断增加。结论NO在地鼠颊囊癌的发生发展中起促进作用,而G NAME起干预作用。     

N-(4-hydroxyphenyl)all-trans-retinamide (4-HPR) high dose effect on DMBA-induced hamster oral cancer: a histomorphometric evaluation

N-(4-hydroxyphenyl)all-trans-retinamide (4-HPR) has shown cancer chemoprevention activity in many experimental and clinical situations. The purpose of this research is to evaluate the in vivo efficacy of 4-HPR in preventing 7,12-dimethylbenz(alpha)antracene (DMBA)-induced oral carcinogenesis and to study histomorphometric changes. 76 Syrian hamsters were separated into four groups: group 1, untreated controls (16 animals); group 2, 4-HPR controls (16 animals); group 3, DMBA-treated animals (28); group 4, animals treated with DMBA and 4-HPR (16). Hamsters were painted with a 0.5% solution of DMBA three times a week in their left buccal pouch. A diet of 2 mmol of 4-HPR/kg was administered. At week 9, 50% of the animals were killed; the remainder were killed at week 12. Pathology and histomorphometric tests were performed on epithelium, dysplasia and carcinomas. At week 9, 5 carcinomas were found in group 3, and 13 in group 4. Cancers in group 4 were more numerous, endophytic and infiltrating than those in group 3 animals. At week 12, 16 carcinomas were detected in group 3 animals, but group 4 developed more carcinomas per animal than group 3. Using these experimental concentrations, 4-HPR cannot express its best chemopreventive effect.     

Role of vitamins C and E as chemopreventive agents in the hamster cheek pouch treated with the oral carcinogen-DMBA

OBJECTIVE: To evaluate the role of vitamins C and E as chemopreventive agents in oral carcinogenesis by optical and ultrastructural studies. MATERIALS AND METHODS: The cheek pouch of male hamsters was treated with the oral carcinogen, dimethylbenz(a)anthracene (DMBA), to induce multiple tumour formation. Vitamins C and E were applied either singly or in combination as a chemopreventive agent. Paraffin and resin-embedded sections of the hamster cheek pouch were studied optically and ultrastructurally. RESULTS: The epithelium of control hamsters showed hyperorthokeratosis and parakeratosis, but did not develop well differentiated squamous cell carcinoma (WDSCC). Ninety percent of the animals treated with DMBA alone showed WDSCC while 10% of the animals developed papillomas. There was also a marked increase in the number of cells undergoing mitosis in this group. A reduction in the yield (1.1 tumour/animal) and rate 60-80% of squamous cell carcinomas but not of papillomas (2.0 papillomas/animal) was observed in groups VI-VIII treated with DMBA and vitamins C and E singly or in combination as compared to those of DMBA only. In animals treated with DMBA plus vitamins C and E, statistical significant decrease in the number of animals with tumours and mitotic basal cells was observed when compared with the DMBA treated group. Control animals showed normal ultrastructural morphology while tumour-bearing animals showed basal lamina in a discontinuous, fragmented, broken and diffused basement membrane, with diminished lamina densa, fewer hemidesmosomes and invagination of the basal cell cytoplasmic processes in the subepithelium. CONCLUSION: These results indicate that vitamin E singly or in combination with vitamin C plays a role in the inhibition of tumour cell growth.     

Chemopreventive effect of Toona sinensis leaf extract on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch squamous cell carcinogenesis

ObjectiveToona sinensis leaf extract (TSL) has been shown to have anti-tumor effects on cancer cell lines. This study aimed to investigate the chemopreventive potential and the underlying mechanism of TSL during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.MethodsOne hundred hamsters were divided into control (n = 30), carcinogenic (n = 20), preventive (n = 42), and therapeutic (n = 8) groups. The animals in carcinogenic and preventive groups were administered reverse osmosis water (carcinogenic group) or TSL (1 g/kg bw) (preventive group) by gavage daily for 4 weeks, and their bilateral pouches were painted with a 0.5% DMBA solution for 4, 9, and 12 weeks. The animals in the therapeutic group were treated with DMBA for 12 weeks prior to TSL administration for 4 weeks. Expression levels of survivin, X chromosome-linked inhibitor of apoptosis (XIAP), proliferating cell nuclear antigen (PCNA), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) proteins were analyzed by immunohistochemistry. Apoptotic activity was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method, cytochrome C, and poly (ADP-ribose) polymerase (PARP).ResultsIn the preventive group, the results showed significant decreases not only in the incidences of squamous cell carcinoma (SCC) (50%) and epithelial dysplasia (62.5%) but also in the tumor number, tumor volume, tumor burden, and the severity of dysplastic lesions. The down-regulation of survivin, XIAP, PCNA, iNOS, and COX-2 proteins and the increased apoptotic activity indicated anti-proliferative and apoptosis-inducing abilities of TSL on DMBA-induced HBP carcinogenesis.ConclusionsThe results suggested that TSL might be a promising candidate for the prevention of oral cancer.     

螺旋藻对DMBA-TPA诱发地鼠口腔癌血管生成的研究

目的:通过研究螺旋藻对金黄地鼠口腔癌血管生成的影响,探讨螺旋藻对口腔癌的阻断作用机理,为临床应用提供理论依据.方法:91只金黄地鼠随机分为5组,阳性对照组及螺旋藻3个不同剂量的用药组,于地鼠左侧颊囊涂二甲基苯并蒽和12-O-四葵酰基-佛波-13-乙酸酯溶液,螺旋藻用药组在涂12-O-四葵酰基-佛波-13-乙酸酯的同时给予不同剂量(200mg/kg;400 mg/kg;800 mg/kg)的螺旋藻混悬液灌胃治疗,同时设阴性对照组.实验结束处死动物进行肿瘤血管生成相关指标的检测.结果:螺旋藻可显著降低地鼠口腔癌的血管密度,表明螺旋藻对血管生成有一定的抑制作用;但是对血管内皮生长因子没有影响.结论:通过抑制新生血管生成,螺旋藻可以阻断口腔癌前病变的进一步发展,但其抑制新生血管的机制需进一步探讨.     

Effect of cyclosporin A on the expression of inducible nitric oxide synthase in the gingiva of rats

BACKGROUND: The role of nitric oxide (NO) in the pathogenesis of cyclosporin A (CsA)-induced gingival overgrowth is still unknown. The purpose of this study was to evaluate the effect of CsA on the expression of nitric oxide synthases (NOS) in the gingival tissue of rats. METHODS: Thirty male Sprague-Dawley rats were randomly assigned to a control and two test groups. Rats in each group received CsA (0, 10, or 30 mg/kg) daily by gastric feeding for 4 weeks. The plasma NO and the NOS enzyme activities were assayed at week 4 in the blood samples and in the gingiva and lung tissue specimens, respectively. The distribution of inducible nitric oxide synthase (iNOS) was further evaluated in tissues obtained from the gingiva and lung at the end of weeks 1 and 4 by immunohistochemistry. RESULTS: In the CsA-treated animals, increased levels of plasma nitrites/nitrates were measured in comparison to those in control rats. Significantly greater iNOS enzyme activities were detected in lung and gingival tissues obtained from CsA-treated animals than from control animals. In addition, cells positively staining for iNOS were clearly observed in both gingival and lung tissues obtained from the CsA-treated animals by immunohistochemistry, whereas a few stained cells were found in those from the control group. The quantity of cells positively stained for iNOS was greater in tissue from week 4 than week 1. CONCLUSIONS: The effect of CsA on gingival iNOS expression was evaluated in rats for 4 weeks. A greater iNOS expression in the gingiva was observed after CsA therapy by both enzyme activities and immunohistochemica staining. Therefore, we suggest that CsA can increase gingival iNOS expression, which may play an important role in cyclosporin-induced gingival overgrowth.     

Cancer-promoting effect of Taiwan betel quid in hamster buccal pouch carcinogenesis

OBJECTIVE: To investigate the cancer-promoting effect of Taiwan betel quid in hamster buccal pouch carcinogenesis.
MATERIALS AND METHODS: Two hundred and fifty-two non-inbred mate adult Syrian golden hamsters were randomly divided into six groups, each containing forty-two animalS. A treatment regimen over a 14-week experimental period was employed with six animals per group being killed at seven different periods (every 2 weeks). The right buccal pouch of each animal was painted three times a week with various combinations of 7, 12-dimethylbenz[a]anthracene (DMBA), Taiwan betel quid extract, dimethyl sulfoxide (DMSO) and mineral oil.
RESULT: Both the number and size of tumors in animals concurrently treated with DMBA and betel quid were significantly higher than those in animals treated with DMBA alone in each killing period of 8, 10, 12 and 14 weekS. No visible tumors but hyperkeratosis and acanthosis were observed in pouches treated with betel quid alone for all killing periods.
CONCLUSION: Our results indicate Taiwan betel quid may be a co-carcinogen in human oral carcinogenesis, if extrapolation can be made from the current animal study.     

Slit蛋白在地鼠颊囊癌变过程中的意义及与血管形成的关系

目的:探讨Slit蛋白在地鼠颊囊癌发展过程中的表达变化及与肿瘤新生血管之间的关系。方法:采用6~8周龄叙利亚金黄地鼠60只,建立DMBA诱发的颊囊癌模型。免疫组化法检测在颊囊癌癌变过程中Slit蛋白、血管内皮生长因子(VEGF)、范德华因子(v-WF)的动态表达,计数新生血管微血管密度(microvasculardense,MVD)的变化。结果:Slit蛋白在原位癌和鳞癌中高表达,与癌前病变和正常黏膜相比有显著性差异(P<0.05),VEGF阳性表达率及微血管密度(MVD)与Slit蛋白的表达呈一致性。结论:Slit蛋白在地鼠颊囊癌的发展中起重要作用,其机制可能是通过促进肿瘤新生血管的形成而发挥促癌作用的。