The Analysis Of E1～e14 Mutation In Apc Gene And The Expression Of P53 Gene In Two Familial Adenomatous Polyposis (fap) Pedigrees

Objective:Familial adenomatous polyposis (FAP) is an autonomic delayed dominant syndrome affecting 1:10,000 people. It is due to a mutation of the APC gene on the chromosome 5q. If left untreated, carriers have an almost 100% chance of developing colorectal cancer by age 40 after having multiple (typically 100s to 1000s) of adenomatous polyps. Since the introduction of screening and prophylactic colostomy, colorectal cancer related death has decreased, while non- colorectal cancer related death has increased.In the families of APC gene mutation, the children of patients have 50% suffering rate. For the present study, the gene mutation sites were related with manifestations of AFP. we identified two FAP pedigrees in our patients with uterine and ovarian manifestations and subsequently performed APC mutation assay for E₁～E₁₄,with a view to obtaining a better insight into its genetic mechanism, thus providing a theoretical basis for establishing a surveillance system.Tumorigenesis is a multifactor and multistage process, which involves the activation of ontogenesis and inactivation of tumor suppressor genes. As a tumor suppressor gene, p53 plays an important role in such a process. There is evidence that p53 profiling has a predictive value in prognosis. In order to better understand its role in proliferation, invasion and metastasis in those patients, p53 expression was also analyzed, using SP immunohistochemical technology. However, whether it can be used as a predictor in FAP or not is still to be determined by further research.Materials and methods1. From 2006 to February in 2007, we have discovered 2 FAP pedigrees through clinical definite, there were 44 person and 14 FAP sufferers in these 2 pedigrees. The experimental group included 9 patients and 24 normal phenotype relatives, and control group included 1 diverging FAP patients. Two groups are both Han people and sex, age are matching. Extracting DNA of subjects and detecting the 1～14 extron mutation through PCR-SSCP and then making sequencing analysis. 2. Collecting the paraffin block of 2 FAP pedigrees patients from 2006 to 2007. There were 20 rectal cancer, 10villous adenomas and 5villous adenomas accompanied atypical hyperplasia and 15 normal contrast. The specimens of every group were stained according to the description of SP kit. P53 protein was detected using an immunohistochemical kit according to the convention SP method.Results1. FAP was autonomic dominant inheritance in 2 pedigrees and there were inheritance anticipation.2. PCR-SSCP showing: DNA immigration strap has not discovered obviously abnormality. Random selecting the different sites amplification products of 1～14 extron mutation in patients and control groups, there was no mutation through verifications.3. The expression of p53 in colorectal cancer tissues of FAP patients showed increasing tendency and increased gradually following the development of tumor.Conclusions:1. This text has not discovered the E₁～E₁₄ mutation of APC gene in 2 pedigrees.2. The happening of FAP has more complicated molecule mechanism. So the APC gene should not as the only one gene to diagnose perhaps.3. P53 gene promotes the development of FAP, and can be used diagnosis of FAP through assisting APC gene.