15-PGDH和COX-2在大肠腺癌中的表达

目的研究NAD+依赖性15-羟基前列腺素脱氢酶(15-PGDH)和环氧合酶-2(Cycboxygenase-2,COX-2)在大肠腺癌组织、大肠腺瘤组织及正常大肠组织中的表达,探讨两者在大肠腺癌组织中的表达情况及其与大肠腺癌临床病理因素的关系。方法应用免疫组织化学(SABC)法检测40例大肠腺癌组织、20例大肠腺瘤组织和20例正常大肠组织中15-PGDH及COX-2的表达情况。结果15-PGDH在大肠腺癌(15%)和腺瘤组织中(20%)的阳性表达率显著低于正常大肠组织(100%)(P0.01),在大肠腺癌和腺瘤中15-PGDH的表达差异无统计学意义(P0.05)。15-PGDH蛋白表达与大肠腺癌患者的性别、年龄、分化程度及Dukes分期和有无淋巴结转移等临床病理参数均无关(P0.05)。COX-2在大肠癌组织(80%)和大肠腺瘤组织中(70%)的表达明显高于正常大肠组织(25%)(P0.01)。且其在大肠癌中的阳性表达率随大肠癌Dukes分期的升高、病理分化程度的降低及远处淋巴结的转移而逐渐增高(P0.05)。大肠癌组织中15-PGDH和COX-2的表达呈负相关(r=-0.544,P=0.000)。结论大肠腺癌组织中15-PGDH的表达缺失或减少可能发生在大肠腺癌发生、发展的早期,是大肠腺癌发生的抑制剂。大肠腺癌组织中COX-2的表达明显增高,其表达的增加可能促进了大肠癌的发生、发展。     

腺瘤样结肠息肉易感基因蛋白截短与大肠腺瘤及大肠癌早期诊断关系

目的探讨腺瘤样结肠息肉(APC)易感基因截短表达水平在大肠腺瘤及大肠癌早期诊断中的价值。方法 34例大肠癌病理标本作为大肠癌组、28例大肠腺瘤标本作为大肠腺瘤组及同期正常大肠组织标本15例作为正常组。3组分别采用蛋白截短检测技术,比较APC基因蛋白截短表达差异。结果正常组APC蛋白截短(+)为0%,大肠腺瘤组42.86%,大肠癌组47.06%,大肠腺瘤组和大肠癌组差异不显著(P0.05);正常组与大肠腺瘤、大肠癌组差异显著(χ2=8.917、P=0.003,χ2=10.481、P=0.001);管状腺瘤组织的APC蛋白截短(+)(75.00%),显著高于绒毛腺瘤组织(20.00%)和混合腺瘤组织(16.67%)(P0.05)。结论 APC蛋白截短(+)表达在不同大肠组织中表达具有一定的差异性,在大肠肿瘤的早期阶段APC蛋白截短(+)表达就存在差异,对早期诊断大肠肿瘤病变具有一定的意义。     

Survivin、MMP-9在大肠腺瘤癌变过程中的表达及其临床意义

目的研究存活素(Survivin)和MMP-9在大肠腺瘤癌变过程中的表达,探讨他们在大肠癌发生、发展、浸润和转移中的作用及其相互关系。方法用免疫组化SABC法和原位杂交技术检测59例大肠腺癌、35例大肠腺瘤(包括21例低度异型增生和14例高度异型增生)和12例癌旁正常大肠黏膜组织中Survivin蛋白、SurvivinmRNA和MMP-9的表达。结果在大肠腺瘤-癌序列演变过程中,Survivin蛋白、mRNA和MMP-9的表达率逐渐升高;正常大肠黏膜、低度异型增生腺瘤与高度异型增生腺瘤、大肠癌间Survivin、MMP-9表达有显著性差异(P<0.05),大肠癌和高度异型增生腺瘤的Survivin、MMP-9表达无显著性差异(P>0.05);SurvivinmRNA阳性强度均低于蛋白表达水平;大肠癌组织中,Survivin的表达与临床病理分型之间均无相关性(P>0.05);MMP-9的表达与浸润深度、Dukes分期、淋巴道转移之间有显著性差异(P<0.05);Survivin与MMP-9两者在大肠腺瘤癌变过程中的表达密切相关(r=0.573,P<0.01)。结论Survivin在大肠腺瘤至癌的演变阶段起重要作用;MMP-9在大肠癌浸润、转移过程中起重要作用;Survivin蛋白表达的调控可能发生在转录以后水平;Survivin与MMP-9存在协同作用或相互调节机制,共同促进肿瘤的发生、发展、浸润和转移。     

CADM1表达下调与大肠腺癌发生发展的关系

目的探讨CADM1表达下调与大肠腺癌发生发展的关系。方法RT—PCR检测正常大肠组织、大肠腺瘤和大肠腺癌的CADM1mRNA表达;免疫组化法检测正常大肠组织、大肠腺瘤和大肠腺癌的CADMI蛋白表达。结果大肠腺瘤中CADM1表达无缺失或明显减少（P〉0．05）;部分大肠腺癌组织中CADM1表达下调,且有淋巴结转移患者比无淋巴结转移者更常见（P〈0．05）,Dukes’C期和Dukes’D期患者比Dukes’A期和Dukes’B期患者更常见（P〈0．05）。结论CADM1表达下调在大肠腺癌中常见,特别是在进展期大肠腺癌,因此,CADM1在大肠腺癌发病机制中可能发挥重要作用。     

核因子—κB与大肠肿瘤细胞凋亡及其调控基因关系的研究

目的;通过观察大肠腺瘤、腺癌和正常组织中的细胞凋亡及其凋亡调控基因Bcl-2,Bcl-Ⅺ和核因子－κB的表达状态,探讨核因子－κB在大肠癌发病过程中的作用。方法：利用DNA缺口末端标记技术和NF－κB,Bcl-2,Bcl-Ⅺ蛋白免疫组化染色,原位检测30例大肠腺瘤和30例大肠腺癌中凋亡细胞和NF－κB,Bcl-2,Bcl-Ⅺ阳性表达细胞的密度和分布,以10例正常大肠组织作对照。结果：NF－κB,Bcl-2,Bcl-Ⅺ蛋白的表达率和表达强度腺癌和腺瘤高于正常组织（P＜0．01）,腺癌高于腺瘤（P＜0．01）。腺癌和腺瘤中的凋亡细胞指数均高于正常组织（P＜0．01）,腺瘤高于腺癌（P＜0．01）。结论：NF－κB在大肠癌发病过程中可能起重要作用。     

大肠腺瘤与大肠腺癌肿瘤相关基因的差异表达

目的:探索大肠腺瘤与大肠腺癌差异表达的肿瘤相关基因.方法:利用基因芯片技术筛选大肠腺瘤与大肠腺癌差异表达的肿瘤相关基因,比较两组基因特点,寻找大肠腺癌重要致病基因,并以RT-PCR对部分差异表达基因进行检测来验证芯片结果.结果:(1)大肠腺瘤差异表达的肿瘤相关基因9个,均上调;(2)大肠腺癌差异表达的肿瘤相关基因47个...     

凋亡相关基因caspase-9、Bcl-2在大肠腺瘤和大肠癌中的表达及意义

目的 探讨凋亡相关基因caspase-9和Bcl-2在大肠腺瘤、大肠癌中的表达及意义。方法 应用免疫组化S-P法检测56例大肠癌、48例大肠腺瘤及20例正常大肠黏膜中的caspase-9和Bcl-2蛋白的表达。用TUNEL法检测细胞调亡。结果 正常大肠黏膜、大肠腺瘤和大肠癌中caspase-9的阳性表达率分别为5.00％、33.33％、64.29％,其表达率在三者间有显著性差异(P<0.01)。Bcl-2在正常大肠黏膜、大肠腺瘤和大肠癌中的阳性表达率分别为15.00％、87.50％、60.71％,三者间亦有显著性差异(P<0.01)。caspase-9,Bcl-2的表达与肿瘤的分化程度有关(P<0.01),与Dukes分期无关(P>0.05)。正常大肠黏膜、腺瘤和大肠癌中凋亡指数有显著性差异(P<0.01),凋亡指数与肿瘤的分化程度有关(P<0.01),与Dukes分期无关(P>0.05)。caspase-9,Bel-2的表达与凋亡指数有密切联系(P<0.01)。结论 在大肠癌形成过程中,caspase-9,Bcl-2参与了肿瘤形成的共同通道;肿瘤早期阶段细胞凋亡的异常和增生过度,楞能是大肠癌的发病原因之一。     

15-PGDH在大肠腺癌中的表达

目的研究NAD+依赖性15-羟基前列腺素脱氢酶(15-PGDH)在大肠腺癌组织、大肠腺瘤组织及正常大肠组织中的表达,探讨15-PGDH在大肠腺癌组织中的表达情况及其与大肠腺癌临床病理因素的关系。方法应用免疫组织化学(SABC)法检测40例大肠腺癌组织、20例大肠腺瘤组织和20例正常大肠组织中15-PGDH的表达情况。结果15-PGDH在大肠腺癌(15%)和腺瘤组织(20%)中的阳性表达率显著低于在正常大肠组织(100%)中的阳性表达率(P0.01),而15-PGDH在大肠腺癌和腺瘤中的表达无统计学差异(P0.05)。15-PGDH蛋白表达情况与大肠腺癌患者的性别、年龄、分化程度及Dukes分期和有无淋巴结转移等临床病理参数均无关系(P0.05)。结论大肠腺癌组织中15-PGDH表达减少或缺失,且其表达与大肠腺癌的分期分化等病理参数并无关系。15-PGDH的表达缺失或减少可能发生在大肠腺癌发生发展的早期,是大肠腺癌发生的抑制物。     

c-Jun、Smad7蛋白在大肠腺癌中的表达及临床意义

目的探讨c-Jun、Smad7蛋白在大肠癌中的表达及其对肿瘤发生、发展的影响。方法采用免疫组化方法,分别检测20例正常大肠黏膜、20例大肠腺瘤及65例大肠腺癌中c-Jun、Smad7蛋白表达水平,比较两种蛋白的表达情况。结果 c-Jun蛋白在大肠腺癌组织中的表达率为72.30%,与正常对照组比较差异有统计学意义(P0.05);高分化腺癌与中-低分化腺癌相比,差异有统计学意义(P0.05);TNMⅢ+Ⅳ期表达率显著低于Ⅰ+Ⅱ期(P0.05);Smad7蛋白在大肠腺癌组织中的表达率为89.23%,与对照组比较差异有统计学意义(P0.05);中-低分化者、有淋巴结转移者与高分化者、无淋巴结转移者比较差异均有统计学意义(P均0.05)。c-Jun蛋白与Smad7蛋白在大肠腺癌中的表达水平呈正相关(P0.05,r s=0.3460)。结论 c-Jun、Smad7蛋白在大肠腺癌的发生、发展整个过程的不同阶段具有促进作用,对于临床诊断大肠癌及判断病情、预后有重要意义。     

MPP3表达减少与大肠癌发病的关系

目的研究MPP3表达减少与大肠癌发病的关系。方法 RT-PCR法检测正常大肠黏膜、大肠腺瘤和大肠癌的MPP3 mRNA表达;Western Blotting法检测正常大肠黏膜、大肠腺瘤和大肠癌的MPP3蛋白表达。结果大肠腺瘤中MPP3表达无明显减少(P>0.05),部分大肠癌组织中MPP3表达减少,且有淋巴结转移患者比无淋巴结转移患者更常见(P<0.05),Dukes C期和D期患者比Dukes A期和B期患者更常见(P<0.05)。结论 MPP3表达减少在大肠癌中为常见现象,而且在晚期肿瘤更明显,因此,MPP3在大肠癌发病中可能发挥重要作用。     

Investigation of Epstein-Barr virus in Chinese colorectal tumors

AIM: To elucidate the association of Epstein-Barr virus (EBV) with colorectal tumors and to demonstrate whether infection of EBV existed in different stages of colorectal tumors involves in the carcinogenesis. METHODS: One hundred and thirty paraffin-embedded tissues of colorectal tumors were classified into 5 groups: 26 adenomas, 23 adenomas complicated with dysplasia, 22 adenomas complicated with carcinomatous, 36 colon carcinoma and 23 HNPCC, were examined by PCR, IHC and ISH, respectively. RESULTS: EBV DNA was detected by PCR in 26 cases out of the 130 specimens, including 5 cases of adenomas, 5 adenomas complicated with dysplasia, 5 adenomas complicated with carcinomatous, 7 colorectal carcinoma and 4 HNPCC. IHC detection showed the expression of LMP1 in 7 cases, including 1 adenoma, 1 adenoma with dysplasia, 1 HNPPC, 2 adenomas complicated with carcinomatous, and 2 colorectal carcinomas. The expression of EBER1 detected by ISH was positive in 6 cases, including 1 adenoma with dysplasia, 2 adenomas complicated with carcinomatous and 3 colorectal carcinomas. There were no significant differences among the results of PCR, IHC and ISH in the 5 groups. In all cases of HNPCC, none of the tumor cells showed positive signals of EBER1, but some EBV-positive tumor infiltrating lymphocytes were found in 2 of 23 cases. CONCLUSION: Our results showed that infection of EBV exists in human colorectal tumors, which indicates that EBV may be involved in the carcinogenesis of colorectal tumors but does not play an important role. The mechanisms need to be clarified further.     

Pathology of colorectal cancer

The earliest phases of colorectal tumourigenesis initiate in the normal mucosa, with a generalised disorder of cell replication, and with the appearance of clusters of enlarged crypts (aberrant crypts) showing proliferative, biochemical and biomolecular abnormalities. The large majority of colorectal malignancies develop from adenomatous polyps. These can be defined as well demarcated masses of epithelial dysplasia, with uncontrolled crypt cell division. An adenoma can be considered malignant when neoplastic cells pass through the muscularis mucosae and infiltrate the submucosa. Definitions like "carcinoma in situ" or "intramucosal carcinoma" should be abandoned, since they lead to confusion. Although several lines of evidence indicate that carcinomas usually originate from pre-existing adenomas, this does not imply that all polyps undergo malignant changes, and does not exclude "de novo" carcinogenesis. Besides adenomas, other types of polypoid lesions include hyperplastic polyps (showing elongated crypts often with cystic dilatation), serrated adenomas (with a serrated glandular pattern], flat adenomas (flat lesions which are difficult to detect in routine lower endoscopy, but may possess malignant potential), hamartomatous polyps (which show a complex branching pattern of smooth muscle supporting normal lamina propria and glands), and inflammatory polyps. Colorectal carcinomas are one of the most frequent neoplasms in Western society; the macroscopic appearance of these lesions may be that of a polypoid vegetating mass or of a flat infiltrating lesion. Most of these tumours are adenocarcinomas (96%), that, in some cases, show a mucinous component. More rare malignancies of the large bowel include signet-ring cell carcinoma, squamous carcinoma, undifferentiated neoplasms and medullary type adenocarcinoma (solid carcinoma with minimal glandular differentiation or slight cellular pleomorphism). Colorectal carcinoma can be graded into well, moderately and poorly differentiated lesions; there is little evidence, however, that grading may be of help in evaluating prognosis of affected patients. In conclusion, colorectal tumours cover a wide range of premalignant and malignant lesions, many of which can easily be removed at endoscopy. It follows that colorectal neoplasms might be prevented by interfering with the various steps of carcinogenesis, which begins with uncontrolled epithelial cell replication, continues with the formation of adenomas of various dimensions, and eventually evolves into malignancy.     

CADM1与DAL-1/4.1B在结直肠癌中的表达及临床意义

目的:研究CADM1和DAL-1/4.1B两种抑癌基因在结直肠癌中的表达并分析两者之间及其与结直肠癌各临床病理参数之间的关系,探讨CADM1和DAL-1/4.1B在结直肠癌发生发展中的作用,为结直肠癌的基因治疗提出新的思路.方法:应用免疫组织化学(SABC法)检测30例结直肠癌组织,10例结直肠腺瘤组织,30例正常结直...     

Comparison of malignant potential between serrated adenomas and traditional adenomas

BACKGROUND: Serrated adenoma is a discrete colorectal epithelial neoplastic lesion that can evolve into colorectal cancer. However, the degree of malignant potential has not been firmly established as yet. The purpose of the present paper was to compare the malignant potential and clinicopathological features between serrated and traditional adenomas. METHODS: A total of 124 serrated adenomas from 116 patients were assessed, and 419 traditional adenomas from 200 were randomly selected. The combination of nuclear dysplasia and serration of > or =20% of crypts was regarded as serrated adenoma. The clinicopathological features of serrated and traditional adenomas were compared, and multivariate analysis performed to confirm whether the malignant potential of serrated adenoma was similar to that of traditional adenoma. RESULTS: The differences in age, sex, total number of adenomas, and synchronous lesions including adenoma with high-grade dysplasia and carcinoma between subjects with and without serrated adenoma were not significant. Serrated adenomas were more frequently located in the rectum and sigmoid colon (P < 0.001), and the average size of serrated adenomas was greater than that of traditional adenomas (P < 0.05). The incidence of malignant lesions including high-grade dysplasia and carcinoma in serrated adenomas was found to be lower than in traditional adenomas (3.2% vs 9.3%, P < 0.05). In the multivariate analysis, adenoma type and polyp size constituted the risk factors for the incidence of high-grade dysplasia and carcinoma. CONCLUSIONS: Serrated adenoma is a premalignant lesion, but it has a lower potential for the development of malignancy than traditional adenomas.     

结肠镜诊疗大肠息肉1537例体会

大肠息肉是常见的肠粘膜病变,其大多数是被视为癌前病变的腺瘤。通过结肠镜检出大肠息肉并加以除,打断腺瘤一腺癌的进程,是防治大肠癌的重要措施。1992年1月至1999年12月8年间,我院7246例结肠镜检查检出大肠息肉1537例(2378枚),检出率21．2％。本对这些患的临床资料进行回顾性分析,希望能力大肠息肉的诊疗及大肠癌的防治工作提供一些有用的资料。     

结肠腺瘤和结肠癌基因表达谱分析

目的 研究结肠腺瘤、结肠癌基因表达谱,筛查结肠癌相关基因.方法 用BRB-Array Tools对公共基因芯片数据库GEO中的结肠腺瘤、结肠癌基因芯片表达数据进行统计学分析,找出在结肠腺瘤和结肠癌发生发展中均发生变化的基因及二者的特异性基因,进一步分析其功能.结果 样本聚类表明各类组织分类正确,比较后得到在腺瘤和腺癌中共同表达的104条基因,其中48条共同上调,56条共同下调;差异基因的功能涉及物质代谢、内环境稳态、细胞间通讯、细胞黏附、细胞增殖等多种肿瘤发生发展的重要生物学过程.结论 生物信息学方法发现的结肠腺瘤、结肠癌基因表达谱可为结肠癌的发病机制及治疗靶位的研究开辟新思路.     

Association of Global DNA Hypomethylation with Clinicopathological Variables in Colonic Tumors of Iraqi Patients

Background/Aim:

Colorectal cancer (CRC) ranks sixth among the most common 10 cancers in Iraq. It is a foremost public health dilemma and there is improved interest in understanding the fundamental principles of its molecular biology. DNA methylation in cancer has become the issue of passionate investigation. As compared with normal cells, the malignant cells show major disruptions in their DNA methylation patterns. We aimed to assess the association of global DNA hypomethylation in colonic adenomas and carcinomas of Iraqi patients, measured by immunohistochemistry of 5-methylcytosin, with different clinicopathological variables.

Patients and Methods:

Thirty tissue paraffin blocks from patients with colorectal adenomas, 30 tissue paraffin blocks from patients with colorectal adenocarcinomas, and 30 samples of apparently normal colonic tissue taken from autopsy cases as a control group were included in the present study. From each block, two sections of 5 μm thickness were taken, one section was stained with Hematoxylin and Eosin for revision of histopathological diagnosis and one section was immunohistochemically stained for 5-methylcytosine (5mC) and digitally analyzed by AperioImageScope software.

Results:

The mean digital value of 5mC immunohistochemical expression was sequentially decreased during neoplastic progression from normal colonic tissue into adenoma and then to carcinoma. The mean digital value of 5mC expression was significantly lower in large size adenomas (≥1 cm), and those with severe dysplasia. Concerning carcinoma cases, 5mC expression was significantly lower in stage C2.

Conclusions:

The immunohistochemical evaluation of 5mC yields refined information on colorectal tumor biology in adenoma and carcinoma. Global DNA hypomethylation reflected by low immunohistochemical expression of 5-mC is associated with advanced colorectal adenomatous polyps suggesting that it is an early event in colorectal carcinogenesis. Also this hypomethylation can reflect bad prognosis of patients with colorectal cancer by its correlation to higher tumor stage.     

Colorectal adenoma to carcinoma progression follows multiple pathways of chromosomal instability

BACKGROUND & AIMS: Current models of colorectal adenoma to carcinoma progression do not fully reflect the genetic heterogeneity and complexity of the disease. The aim of the present study was to identify genetic changes discriminating adenomas that have progressed to carcinoma from adenomas that have not progressed, and to refine the current genetic models of colorectal adenoma to carcinoma progression, based on a genome-wide analysis of chromosomal aberrations. METHODS: Sixty-six nonprogressed colorectal adenomas, 46 progressed adenomas (malignant polyps), and 36 colorectal carcinomas were screened for chromosomal aberrations by comparative genomic hybridization, and for mutations in the adenomatous polyposis coli (APC) and K-ras gene. Data analysis focused on cancer-associated genetic changes in adenomas. RESULTS: Accumulation of losses in 8p21-pter, 15q11-q21, 17p12-13, and 18q12-21, and gains in 8q23-qter, 13q14-31, and 20q13 were strongly associated with adenoma-to-carcinoma progression, independent of the degree of dysplasia. Hierarchic cluster analysis demonstrated the presence of 3 distinct subgroups of adenomas, characterized by unique combinations of genetic aberrations in the adenomas (17p loss and K-ras mutation, 8q and 13q gain, and 18q loss and 20q gain, respectively). CONCLUSIONS: The presence of 2 or more of the aforementioned 7 chromosomal changes was associated with progressed colorectal adenomas and colorectal cancer. In addition, evidence was found that these chromosomal abnormalities occurred in specific combinations of a few abnormalities rather than as a mere accumulation of events, indicating the existence of multiple independent chromosomal instability pathways of colorectal cancer progression.     

Surveillance strategies in patients after polypectomy

Colorectal cancer (CRC) is a major cause of cancer death in the Western world. It develops slowly over several years from premalignant lesions (most prominently adenomatous polyps) to invasive cancer. The molecular basis of CRC pathogenesis has been well characterized. The most effective method to prevent CRC is endoscopic polypectomy. However, adenomatous polyps are known to recur at significant rates. The aim of surveillance programs after polypectomy is to further reduce the incidence of CRC in individuals where precancerous lesions have been identified and treated. However, the medical risks and the costs of repeated examinations must be kept as low as possible. Therefore, the identification of patient subgroups with a particular low cancer risk who may be followed-up less frequently seems important. There is recent evidence that other colorectal lesions, namely flat and depressed type adenomas (F&D adenoma) and possibly some hyperplastic polyps and serrated adenomas may also carry a malignant potential which could influence our screening, treatment and surveillance strategies for the colorectum in the future. General surveillance guidelines regarding these entities have not been issued to date. This article will first discuss the biology, natural history, present surveillance recommendations and future issues for sporadic adenomatous polyps. Then, recent literature on F&D type adenomas, hyperplastic polyps and serrated adenomas will be reviewed with respect to their malignant potential and the potential necessity for treatment and surveillance of these lesions.