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51.
Background and Aim: Gastric adenomas (GAs) are considered as premalignant lesions of gastric adenocarcinoma. The role of Wnt signaling pathway in GAs is rarely identified. In the present study, we aimed to determine whether Wnt signaling plays a role in the pathogenesis of GAs, and to clarify the mechanism of Wnt signaling in GAs. Methods: The study investigated the relationship between clinicopathological characteristics, Helicobacter pylori (Hp) infection, adenomatous polyposis coli (APC) promoter methylation, APC and β‐catenin immunohistochemistry expression and mutation status, compared with 38 gastric adenoma and periadenomatous tissues (PTs). Results: The abnormal expression of β‐catenin in PTs, low‐grade adenomas (LGAs) and high‐grade adenomas (HGAs) was 0%, 9.09% and 81.25%. For APC, immunoreactive score (IRS) was 5.50 ± 0.5 in PTs, 3.59 ± 1.4 in LGAs and 1.8 ± 2.0 in HGAs. The scores in LGAs and HGAs were significantly lower than those in PTs (P = 0.000). IRS reflected significantly reduced expression of APC in HGAs (P = 0.002). The absent expression of APC had a correlation with the expression of β‐catenin (P = 0.000). Four LGAs (18.18%) and nine HGAs (56.25%) had methylation of APC. APC promoter methylation correlated with the grade (P = 0.014) and the expression of β‐catenin and APC (P = 0.000). Genes mutation was detected in only two adenomas (5.3%). The presence of Hp in HGAs (43.8%) was significantly higher than in LGAs (13.6%) (P = 0.038). But there was no statistical correlation to growth pattern, size, APC hypermethylation and gene mutation. Conclusion: Hypermethylation of APC promoter, instead of mutations involving APC and β‐catenin, may play a role in the development and progression of GAs contributing to moderate activation of Wnt signaling. Helicobacter pylori may accelerate the progress of gastric adenoma, but the pathogenesis needs further research.  相似文献   
52.
Restorative proctocolectomy (RP) is the treatment of choice in patients affected with refractory ulcerative colitis or familial adenomatous polyposis. Surgery in elective settings is often performed in 2 stages, fashioning an ileostomy which is closed 2-3-mo later. It is still debated whether omitting ileostomy could offer advantages in the management of patients undergoing RP.  相似文献   
53.
Aim The aim of the study was to evaluate intra‐operative difficulties, complications and long‐term bowel function in polyposis patients undergoing conversion of an ileorectal anastomosis to an ileoanal pouch, compared with patients with a primary ileoanal pouch operation. Method A national register‐based retrospective study was performed with clinical follow‐up and a questionnaire on long‐term bowel function. Results There were 84 patients in the study: 59 (70%) had a primary pouch operation and in 25 (30%) a secondary pouch procedure was attempted. This was abandoned, in one case, leaving 24 patients who had a successful secondary restorative proctocolectomy. The median (range) follow‐up was 123 (0–359) months. There were no intra‐operative difficulties in the 59 primary operations, but intra‐operative difficulties were reported in nine of 25 secondary operations (P < 0.001). Complications within 1 month of surgery occurred in six of 59 primary operations and in none of 24 secondary operations (P < 0.001); and late surgical complications occurred in eight of 55 primary operations and in eight of 24 secondary operations (P = 0.13). The only difference in bowel function was a lower frequency of nocturnal defaecation after secondary pouch formation (P = 0.02). Conclusion Reoperation with proctectomy after a previous ileorectal anastomosis and conversion to restorative proctocolectomy is feasible in polyposis patients, with morbidity and functional results similar to those seen after a primary pouch operation.  相似文献   
54.
家族性腺瘤性息肉病癌变危险因素分析   总被引:3,自引:1,他引:2  
樊人瑜  许建明 《安徽医学》2016,37(3):276-279
目的 探讨家族性腺瘤性息肉病(FAP)相关性结直肠癌及其癌变危险因素,为监测预防FAP癌变提供依据。方法 收集我院确诊的65例FAP患者,根据患者是否发生癌变,分为FAP癌变组(35例)与未癌变组(30例),统计分析FAP相关性结直肠癌发生的危险因素。结果 在65例FAP患者中,35例患者经病理确诊发生癌变,癌变率为53.85%。发病年龄、腺瘤数量、腺瘤大小及腺瘤组织学类型是影响FAP癌变的相关因素(P<0.05),且和癌变呈显著正相关。结论 FAP癌变倾向极高,发病年龄、腺瘤数量、腺瘤大小及腺瘤组织学类型是影响FAP癌变的相关因素,与癌变呈正相关。  相似文献   
55.

Background

Identification of hereditary predisposition to cancer has limited significance if not followed by efficient cancer prevention in the family. Probands are traditionally left to inform their relatives about the increased risk, but distant relatives may remain uninformed. An approach to contacting directly at‐risk persons assumed to be unaware of their increased cancer risk was taken. With cancer prevention as the ultimate goal, the study was aimed at investigating attitudes towards and psychosocial consequences of this novel strategy.

Methods

In families with hereditary non‐polyposis colorectal cancer (Lynch syndrome), 286 healthy adult relatives with a 50% risk of a predisposing mutation were contacted by letter. Of these, 112 participated in counselling and predictive testing. Baseline information and information obtained 1 month after the test for 73 respondents were compared with 299 corresponding subjects, approached via the proband (family‐mediated approach in our previous study) in these families.

Results

After the contact letter, 51% consented to the study. Of these, 92% approved of the direct contact and 33% had tried to seek information. In 34% of the mutation carriers, neoplasia was identified in the first post‐test colonoscopy. Although post‐test fear of cancer increased among the mutation carriers and decreased among noncarriers, almost all participants were satisfied with their decision to participate, independently of their test results, parallel to the family‐mediated approach.

Conclusion

In this large‐scale study, relatives in cancer families were actively contacted to inform them of the condition and genetic counselling. Their attitudes were encouraging, and the psychosocial consequences were similar to the family‐mediated approach. Our results suggest the appropriateness of direct contact as an alternative method of contact in cases of life‐threatening treatable disease.  相似文献   
56.
OBJECTIVE: The abnormalities of the Wnt signalling pathway in desmoid-type fibromatosis were analysed, with the purpose of exploring the mechanism of tumorigenesis and progression. METHODS: The clinical and histopathological features of 96 cases were analysed. Beta-catenin, cyclin-D1, c-myc, and Ki-67 proteins were detected in 69 cases using formalin-fixed, paraffin-embedded tissues. Using the same materials, apoptosis of the tumour cells was investigated by terminal deoxynucleotidyl transferase mediated dUTP nick end-labelling (TUNEL) testing. Polymerase chain reaction (PCR), denaturing high performance liquid chromatography (DHPLC) assay, and sequencing were performed to detect abnormalities of the adenomatous polyposis coli (APC) and beta-catenin genes. RESULTS: APC gene mutations were found in 18 cases (26.1%, 18/69). Somatic mutations of codon 41 in exon 3 of beta-catenin were detected in 13 cases (18.8%, 13/69). No correlation of beta-catenin abnormal expression with the mutations of APC gene or beta-catenin gene was identified (p>0.05). The cases with abnormal beta-catenin expression showed a higher level of c-myc protein expression (69.7%, 23/33) than those without (22.2%, 8/36, p = 0.001). The apoptotic indices (AIs) were significantly lower in cyclin-D1 positive cases and c-myc positive cases (p = 0.015, p = 0.007). CONCLUSIONS: There are somatic mutations of the APC and beta-catenin gene in desmoid-type fibromatosis, and there are abnormalities in the Wnt signalling pathway. These abnormalities may result in aberrant cell proliferation and apoptosis, which are likely to be important factors in tumorigenesis and progression.  相似文献   
57.
Tan LP  Ng BK  Balraj P  Lim PK  Peh SC 《Pathology》2007,39(2):228-234
BACKGROUND AND AIMS: Colorectal cancers of different subtypes involve different pathogenic pathways like the Wnt and the mutator pathways. In this study, we screened 73 colorectal cancer cases from a multi-racial group for genetic and expression profile defects with the aim of correlating these with patients' clinicopathological characteristics. METHODS: Mutation screening of the entire coding region of APC and exon 3 of CTNNB1, loss of heterozygosity (LOH) of APC, and microsatellite instability (MSI) status were assessed for 44 patients with available paired frozen normal and tumour tissues. In addition, 29 cases with available paraffin embedded tumour blocks were screened for mutation in exon 3 of CTNNB1, the APC mutation cluster region (codon 1286-1513), and hMLH1, hMSH2, hMSH6 protein expressions by immunohistochemistry method. RESULTS: In our study, 15/73 cases showed APC mutations (20.5%), 1/73 cases had CTNNB1 mutation (1.4%), 5/32 cases had APC LOH (15.6%), and 16/70 (22.9%) cases revealed at least some form of mismatch repair (MMR) defect. Tumour grade (poor differentiation) was found to correlate significantly with right-sided tumour and mucinous histology (p = 0.01879 and 0.00320, respectively). Patients of younger age (below 45 years) more often had tumours of mucinous histology (p = 0.00014), while patients of older age (above 75 years) more often had tumours on the right side of the colon (p = 0.02448). Tumours of the mucinous histology subtype often had MMR defects (p = 0.02686). There was no difference in the occurrence of APC and CTNNB1 mutations and MMR defects found within our multi-racial colorectal cancer patient cohort. CONCLUSION: Our findings support the notion that racial factor may not be related to the occurrence of MMR defects and APC and CTNNB1 mutations in our multi-racial patient cohort.  相似文献   
58.
The interaction of urokinase-type plasminogen activator (uPA) and its receptor, uPAR, on cell surfaces facilitates the generation of cell-bound plasmin, thus allowing cells to establish a proteolytic front that enables their migration through protein barriers. This complex also activates cell signalling pathways that influence cell functions. Clinical studies have identified uPA as an indicator of poor overall survival in patients with colorectal cancer. In the current study, a mouse model of colon cancer, Apc(Min/+), with an additional deficiency of uPA (Apc(Min/+)/Plau-/-) was used to determine the effects of uPA on tumour initiation and growth. Utilizing this model, it was found that the number of tumours was diminished in these mice relative to Apc(Min/+) mice, which correlated with the decreased leukocyte infiltration in the tumours. However, tumour growth was not impeded in Apc(Min/+)/Plau-/- mice, and proliferation and tumour vascularization were, in fact, enhanced in Apc(Min/+)/Plau-/- mice. These latter effects are consistent with a mechanism involving up-regulation of COX-2 expression and Akt pathway activation in Apc(Min/+)/Plau-/- mice. The results from this study suggest that uPA plays dual and opposing roles in regulating lesion development: one early, during the transition from normal epithelia to dysplastic lesions, and another later during tumour growth.  相似文献   
59.
A small fraction of families with familial adenomatous polyposis (FAP) display an attenuated form of FAP (AFAP). We aimed to assess the presence of germline mutations in the MUTYH and adenomatous polyposis coli (APC) genes in AFAP families and to compare the clinical features between the two causative genes. Families with clinical AFAP were selected from the Dutch Polyposis Registry according to the following criteria: (a) at least two patients with 10-99 adenomas diagnosed at age >30 years or (b) one patient with 10-99 adenomas at age >30 years and a first-degree relative with colorectal cancer (CRC) with a few adenomas, and, applying for both criteria, no family members with more than 100 polyps before the age of 30 years. All probands were screened for germline mutations in the APC and MUTYH genes. Twenty-five of 315 Dutch families with FAP (8%) met our criteria for AFAP. These families included 146 patients with adenomas and/or CRC. Germline APC mutations were identified in nine families and biallelic MUTYH mutations in another nine families. CRC was identified at a mean age of 54 years (range 24-83 years) in families with APC and at 50 years (range 39-70 years) in families with MUTYH (p = 0.29). APC and biallelic MUTYH mutations are responsible for the majority of AFAP families. Based on our results and those reported in the literature, we recommend colonoscopy once every 2 years in AFAP families, starting surveillance from the late teens in APC mutation carriers and from age 20-25 years in biallelic MUTYH mutation carriers.  相似文献   
60.
目的探讨肝细胞核因子-1α(HNF-1α)基因突变协同腺瘤样结肠息肉病基因(APC)突变对家族性腺瘤性息肉病(FAP)细胞增殖的影响。 方法利用RNA干扰技术,构建HNF-1α基因突变协同APC突变细胞模型,通过MTT法、克隆形成、划痕试验、细胞迁移、细胞侵袭及致瘤等实验观察HNF-1α基因突变协同APC突变对FAP细胞的增殖能力。 结果与单突变组比较,HNF-1α基因突变协同APC突变组FAP细胞具有较强的细胞克隆形成、细胞迁移、细胞侵袭及致瘤性。 结论HNF-1α基因协同APC突变促进了FAP细胞增殖。  相似文献   
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