SREBP-1及内源性脂肪酸合成相关蛋白在散发性大肠管状腺瘤癌变过程中的作用

发布时间：2018-03-16 04:17

本文选题：大肠管状腺瘤　切入点：癌变　出处：《河北医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的:大肠癌是常见的消化道恶性肿瘤之一,其发病率呈上升趋势。大肠腺瘤与大肠癌关系密切,约80%大肠癌由大肠腺瘤演变而来,其形成及癌变机制错综复杂,目前尚不明确。脂类代谢异常在肿瘤发生发展中的作用日益受到关注。脂质代谢改变尤其是脂肪酸合成显著增加是肿瘤细胞快速增殖的一个重要标志,不同于正常细胞直接利用循环中的脂肪酸,恶性肿瘤细胞生长增殖所需的脂肪酸主要来源于从头合成途径。固醇调节原件结合蛋白1(isterol regulatory element-binding proteins-1,SREBP-1)是调控脂肪酸从头合成途径(DNL)中的关键因子,直接影响脂肪酸从头合成途径中关键酶脂肪合酶(fatty acid synthase,FASN)的生成。FASN是SREBP-1的下游靶基因,二者合称为代谢原癌基因。研究发现在不同类型肿瘤的相对早期阶段,脂肪酸合成通路就已开始上调并且SREBP-1在肺癌、乳腺癌、卵巢癌等肿瘤细胞中呈高表达,但在大肠癌中的相关研究鲜见报道。SREBP-1的活性主要受PI3K-Akt-mTOR通路调节,通路中的哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin complex,mTOR)及上游刺激因子1(upstream stimulatory factors 1,USF1)对SREBP-1起重要调节作用:mTOR通过增加TSC1/2的表达及促进Akt在S473位点的磷酸化而上调SREBP-1表达;USF1其基本HLH结构域直接与SREBP-1的N-末端区域的HLH结构域相互作用,从而也对SREBP-1的表达起到促进作用。为探讨脂肪酸的从头合成途径是否在散发性大肠管状腺瘤癌变过程中发挥作用,本研究采用免疫组化方法检测脂肪酸从头合成途径中的关键蛋白SREBP-1、p-mTOR、FASN及USF1的表达情况并对结果进行相关性分析,进一步揭示其在大肠腺瘤癌变中的意义,为大肠腺瘤癌变预防和临床治疗及预后提供理论依据。方法:1采用免疫组织化学SP法检测SREBP-1及内源性脂肪酸合成相关因子(p-mtor、USF1、fasn)在40例正常大肠黏膜、112例不同程度异型增生大肠管状腺瘤以及100例大肠管状腺瘤癌变组织中的表达,分析其与临床病理特征的关系,并进一步进行相关性分析。2用spss21.0软件对实验数据进行分析,应用χ2检验、wilcoxon符号秩和检验和spearman相关性分析,p0.05代表有统计学意义。结果:1免疫组织化学结果1.1SREBP-1在散发性大肠管状腺瘤癌变过程中的表达情况SREBP-1蛋白在正常大肠黏膜组、异型增生组和瘤癌变组中的阳性表达率分别为7.5%、37.5%、77.0%,其中腺瘤组和癌变组明显高于正常粘膜组(p0.05),癌变组明显高于腺瘤组(p0.05)。SREBP-1蛋白在上皮轻、中、重度异型增生管状腺瘤组的阳性表达率分别为20.0%、35.0%、62.5%,依次升高(p0.05)。其中重度异型增生组高于轻、中度异型增生组(p0.05),轻度及中度异型增生组间无差异(p0.05)。1.2p-mtor在散发性大肠管状腺瘤癌变过程中的表达情况p-mtor蛋白在正常大肠黏膜组、管状腺瘤异型增生组和管状腺瘤癌变组中的阳性表达率分别为5.0%、34.8%、87.0%,依次升高(p0.05),其中腺瘤组和癌变组明显高于正常粘膜组(p0.05),癌变组明显高于腺瘤组(p0.05)。p-mtor蛋白在上皮轻、中、重度异型增生管状腺瘤组中的阳性表达率分别为17.7%、35.0%、59.4%,依次升高(p0.05),其中重度异型增生组高于轻、中度异型增生组(p0.05),中度异型增生组高于轻度异性增生组(p0.05)。1.3fasn在散发性大肠管状腺瘤癌变过程中的表达情况fasn蛋白在正常大肠黏膜组、管状腺瘤异型增生组和管状腺瘤癌变组中的阳性表达率分别为10.0%、32.1%、85.0%,依次升高(p0.05),其中腺瘤组和癌变组明显高于正常粘膜组(p0.05),癌变组明显高于腺瘤组(p0.05)。fasn蛋白在上皮轻、中、重度异型增生管状腺瘤组中的阳性表达率分别为12.5%、32.5%、56.3%,依次升高(p0.05),其中重度异型增生组明显高于轻、中度异型增生组(p0.05),中度异型增生组高于轻度异性增生组(p0.05)。1.4USF1在散发性大肠管状腺瘤癌变过程中的表达情况USF1蛋白在正常大肠黏膜组、异型增生管状腺瘤组和管状腺瘤癌变组中的阳性表达率分别为20.0%、47.3%、65.0%,依次升高(p0.05),其中腺瘤组和癌变组明显高于正常粘膜组(p0.05),癌变组高于腺瘤组(p0.05)。USF1蛋白阳性表达率在上皮轻、中、重度异型增生管状腺瘤组依次升高(分别为20.0%、42.5%、87.5%),其中重度异型增生组明显高于轻、中度异型增生组(p0.05),中度异型增生组明显高于轻度异型增生组(p0.05)。2SREBP-1及内源性脂肪酸合成相关蛋白(p-mtor、fasn及USF1)与临床病理特征关系2.1SREBP-1蛋白的表达与临床病理特征关系管状腺瘤癌变组中SREBP-1蛋白阳性表达率与肿瘤分化程度相关,随着分化程度的降低,SREBP-1蛋白阳性表达率依次升高(χ2=18.368,p0.05);与性别、年龄、肿瘤发生部位、淋巴结转移、dukes分期以及浸润深度无相关性(p0.05)。2.2p-mtor蛋白的表达与临床病理特征关系癌变组中p-mtor蛋白阳性表达率与肿瘤分化程度、浸润深度相关,随着分化程度降低、浸润深度增加,p-mtor蛋白阳性表达率增高(χ2=6.917、χ2=7.078,均p0.05);而与性别、年龄、肿瘤发生部位、淋巴结转移及dukes分期无相关性(p0.05)。2.3fasn蛋白的表达与临床病理特征关系癌变组中fasn蛋白异常表达率与分化程度,随着分化程度降低,fasn蛋白异常表达率增高(χ2=10.080,p0.05);与性别、年龄、肿瘤发生部位、dukes分期、浸润深度和淋巴结转移无相关性(p0.05)。2.4USF1蛋白的表达与临床病理特征关系癌变组中USF1蛋白阳性表达率与分化程度,随着分化程度降低,USF1蛋白阳性表达率增高(χ2=8.487,p0.05);而与性别、年龄、肿瘤发生部位、dukes分期、浸润深度和淋巴结转移无相关性(p0.05)。3SREBP-1与内源性脂肪酸合成相关蛋白(p-mtor、fasn及USF1)的相关性分析结果显示腺瘤组SREBP-1与p-mtor、fasn、USF1呈正相关(r=0.247,r=0.494,r=0.397,p0.05);癌变组SREBP-1与p-mtor、FASN、USF1呈正相关(r=0.213,r=0.702,r=0.247,P0.05)。结论:1 SREBP-1蛋白表达随着腺瘤异型增生程度的增高及癌变的出现,其阳性表达率明显增高,并且与大肠癌分化程度有关,提示SREBP-1可能参与了散发性大肠管状腺瘤癌变的发生发展。2脂肪酸从头合成相关因子(p-mTOR、FASN、USF1)在正常大肠粘膜、不同程度异型增生管状腺瘤组和腺瘤癌变组中表达均依次升高,提示可能与大肠癌的发生发展有关。3 SREBP-1与脂肪酸从头合成相关因子呈正相关,提示SREBP-1与脂肪酸从头合成相关因子(p-mTOR、FASN、USF1)可能在散发性大肠管状腺瘤癌变过程中发挥协同作用。
[Abstract]:Objective: colorectal cancer is one of the most common malignant tumor of digestive tract. Its incidence is rising. The relationship between colorectal adenoma and colorectal cancer closely, about 80% colorectal adenoma by evolution, the formation and mechanism of carcinogenesis perplexing, it is not clear. The abnormal lipid metabolism in the development of tumors in the role of increasingly attention. Altered lipid metabolism especially fatty acid synthesis increased significantly is an important sign of the rapid proliferation of tumor cells, unlike normal cells directly using fatty acid cycle, fatty acid the main source of malignant tumor cell growth and proliferation required in de novo synthesis of sterol regulatory element binding protein 1. (isterol regulatory element-binding proteins-1. SREBP-1) is the regulation of fatty acid biosynthesis pathway (DNL) in the key factor, directly affect the key enzyme of fatty fatty acid biosynthesis pathway (fatty synthase ACI D synthase, FASN) generation.FASN is a downstream target gene of SREBP-1, two of them are called metabolic gene. The study found in the relatively early stage of different tumor types, fatty acid synthesis pathway has been up-regulated and SREBP-1 in lung cancer, breast cancer, ovarian cancer and other tumor cells showed high expression, but in in colorectal cancer related research reported the activity of.SREBP-1 is mainly affected by the PI3K-Akt-mTOR pathway, mTOR pathway in (mammalian target of rapamycin complex, mTOR) and upstream stimulatory factor 1 (upstream stimulatory 1 factors, USF1) of SREBP-1 play an important regulatory role: mTOR by increasing the expression of TSC1/2 and Akt in promoting S473 phosphorylation and upregulation of the expression of SREBP-1 USF1 HLH; the basic domain of HLH directly with the N- terminal region of SREBP-1 interaction, and the expression of SREBP-1 to In order to investigate the role. De novo fatty acid synthesis pathway does play a role in the carcinogenesis of sporadic colorectal tubular adenoma in this study, immunohistochemical method was used to detect the fatty acid biosynthesis pathway in the expression of SREBP-1, p-mTOR, expression of FASN and USF1 and analyzed the correlation of the results further revealed in colorectal adenomas the significance of cancer, and provide a theoretical basis for the prevention and treatment of colorectal adenoma and prognosis. Methods: 1 Immunohistochemical SP method was used to detect the expression of SREBP-1 and endogenous fatty acid synthesis related factors (p-mTOR, USF1, FASN) in 40 cases of normal colorectal mucosa, the expression of 112 cases of dysplasia and 100 cases of colorectal colorectal tubular adenoma tubular adenoma carcinoma and analyze its relationship with clinical pathological characteristics, and further analyzed the.2 of the experimental data using spss21.0 software Analysis and application of 2 test analysis, Wilcoxon signed rank test and Spearman correlation was statistically significant P0.05. Results: 1 immunohistochemical results of 1.1SREBP-1 in the carcinogenesis of sporadic colorectal tubular adenoma in the expression of SREBP-1 protein in normal colorectal mucosa, the positive expression of dysplasia group and cancerous tumor group respectively 7.5%, 37.5%, 77%, one adenoma group and cancer group was significantly higher than that in normal mucosa group (P0.05), cancer group was significantly higher than that in adenoma group (P0.05) and.SREBP-1 protein in epithelial light, severe dysplasia tubular adenoma group positive expression rates were 20%, 35%, 62.5%, followed by increased (P0.05). The severe dysplasia group was higher than that of light, moderate dysplasia group (P0.05), no difference between the groups of mild and moderate dysplasia (P0.05) expression of p-mTOR protein.1.2p-mtor in sporadic colorectal tubular adenoma carcinoma during deformation In the normal colorectal mucosa, the positive expression of tubular adenoma dysplasia group and tubular adenoma with cancerous changes. The rates were 5%, 34.8%, 87%, (P0.05), which in turn increased adenoma group and cancer group was significantly higher than that in normal mucosa group (P0.05), cancer group was significantly higher than that in adenoma group (P0.05) and.P-mtor protein in epithelial light. In severe dysplasia tubular adenoma group positive expression rates were 17.7%, 35%, 59.4%, (P0.05), which were significantly higher in severe dysplasia group was higher than that of light, moderate dysplasia group (P0.05), moderate dysplasia group was higher than that of mild dysplasia group (P0.05).1.3fasn in the carcinogenesis of sporadic colorectal tubular adenoma in expression FASN protein in normal colorectal mucosa, the positive expression of tubular adenoma dysplasia group and tubular adenoma with cancerous changes. The rates were 10%, 32.1%, 85%, (P0.05), which in turn increased adenoma group and cancer group Higher than that in normal mucosa group (P0.05), cancer group was significantly higher than that in adenoma group (P0.05) and.Fasn protein in epithelial light, severe dysplasia tubular adenoma group positive expression rates were 12.5%, 32.5%, 56.3%, (P0.05), which were significantly higher in severe dysplasia group was significantly higher than that of mild, moderate dysplasia group (P0.05). Moderate dysplasia group was higher than that of mild dysplasia group (P0.05).1.4USF1 in the carcinogenesis of sporadic colorectal tubular adenoma in the expression of USF1 protein in normal colorectal mucosa, the positive expression of dysplasia tubular adenoma and tubular adenoma with cancerous changes. The rates were 20%, 47.3%, 65%, (P0.05), which in turn increased adenoma group and cancer group was significantly higher than that in normal mucosa group (P0.05), cancer group was higher than that in adenoma group (P0.05) the positive rate of.USF1 protein expression in epithelial light, severe atypical hyperplasia of tubular adenoma were increased in turn (respectively 20%, 42.5%, 87 .5%), the severe dysplasia group was significantly higher than that of mild, moderate dysplasia group (P0.05), moderate dysplasia group was significantly higher than that in mild dysplasia group (P0.05).2SREBP-1 and endogenous fatty acid synthesis related protein (p-mTOR, FASN and USF1) and SREBP-1 expression in clinical and pathological features of the relationship between 2.1SREBP-1 protein and clinicopathological features of tubular adenoma with cancerous changes. The expression rate and the degree of tumor differentiation, along with the lower degree of differentiation, the positive expression rate of SREBP-1 protein increased (x 2=18.368, P0.05); and gender, age, location of tumor, lymph node metastasis, dukes staging and invasion depth (P0.05) had no correlation relationship between.2.2p-mtor protein expression and clinicopathological features of positive the expression of p-mTOR protein in carcinoma group were related with the degree of differentiation, depth of invasion, with lower differentiation degree, infiltration depth increased, p-mTOR protein positive expression The rate increased (x 2=6.917, X 2=7.078, P0.05); and gender, age, tumor location, lymph node metastasis and Dukes stage (P0.05) there is no correlation between the abnormal expression of the relationship between.2.3fasn protein expression and clinicopathological features of FASN carcinoma group in the rate of protein and the degree of differentiation, with lower differentiation, abnormal expression of FASN the rate of protein increased (x 2=10.080, P0.05); and gender, age, location of tumor, dukes staging, depth of invasion and lymph node metastasis (P0.05) the relationship between.2.4USF1 protein expression and clinicopathological features of positive expression of USF1 protein in carcinoma group and differentiation rate, with the decrease of differentiation, the positive expression rate of USF1 protein increased (2=8.487, P0.05); and gender, age, location of tumor, dukes staging, depth of invasion and lymph node metastasis (P0.05.3SREBP-1) and endogenous fatty acid synthesis related protein (p-mTOR, FASN and USF1 ) the correlation analysis showed that SREBP-1 and p-mTOR FASN adenoma group, and USF1 was positively correlated (r=0.247, r=0.494, r=0.397, P0.05); group SREBP-1 and FASN cancer p-mTOR, USF1 was positively correlated (r=0.213, r=0.702, r=0.247, P0.05). Conclusion: the expression of SREBP-1 1 protein with higher degree of dysplasia and cancerous adenoma the positive expression rate was significantly increased, and associated with degree of differentiation, suggesting that SREBP-1 may be involved in the occurrence and development of.2 fatty acid biosynthesis related factors in carcinogenesis of sporadic colorectal tubular adenoma (p-mTOR, FASN, USF1) in normal colorectal mucosa, different dysplasia tubular adenoma group and adenoma group expression were in turn increased, suggesting that it may be related to the occurrence and development of.3 SREBP-1 and fatty acid biosynthesis related factors were positively related with colorectal cancer, suggesting that SREBP-1 and fatty acid biosynthesis related factors (p-mTOR, FASN, USF1) It may play a synergistic role in the carcinogenesis of sporadic tubular adenomas.

【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R735.34

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