p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results sho...p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37. 5 % (3/8), 42. 11 % (8/19), 53. 33 (16/30) respectively- There was significant dif-ference among groups of metaplasia, dysplasia, cancer and normal controls. Noexon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course ofprecancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6,APC was 47,37 % (9/19), 8. 73% (2/23), 16. 67 % (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis,depth of invasion- LOH of exon4 may be one of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis展开更多
Late stage colorectal carcinoma is very complicated in its molecular mechanisms. One hundred andnine cases of colorectal carcinomas were analyzed with RFLP method for the allelic deletion of chromosome 17short arms (A...Late stage colorectal carcinoma is very complicated in its molecular mechanisms. One hundred andnine cases of colorectal carcinomas were analyzed with RFLP method for the allelic deletion of chromosome 17short arms (ADCC17p) In this study. The results showed that frs(luency of allelic deletion of chromosome 17short arms (FADC17P) in Dukes’ D stage (95 % ) was higher than those in Dukes’ A, B. C stages (54% 68% ); Fisher’s exact test P <0. 01; FADC17p in colorectal carcinomas with distant metastasis (95 % ) washigher than those without distant metastasis, Fisher’s exact test P <0. 01 However, there were no significant differences in FADC 1 7p between the colorectal carcinomas with lymph node metastasis and those without lymph node metastasis (P >0. 05). Therefore, it is considered that ADC17p is an important diagnosticmarker of late stage colorectal carcinomas, and indicates a poor prognosis.展开更多
Background Our previous study confirmed that oligodendrogliomas had higher frequency of chromosome 1p/19q deletion. In order to improve the diagnostic criteria and to predict the prognosis of oligodendroglioma patient...Background Our previous study confirmed that oligodendrogliomas had higher frequency of chromosome 1p/19q deletion. In order to improve the diagnostic criteria and to predict the prognosis of oligodendroglioma patients, the status of chromosome 1 p/19q deletion, the methylation of O6-methylguanine-DNA methyltransferase （MGMT）, and the expression of p53 protein were evaluated and investigated in relation to patients＇ outcomes.Methods Methylation of MGMT in 73 cases was analyzed by nested methylation-specific PCR （MSP）. The levels of MGMT and p53 protein were tested with immunohistochemistry. Pearson＇s chi-square test and Fisher＇s exact test were used. Multivariate and Kaplan-Meier analysis were performed to determine patients＇ outcomes.Results Both oligodendrogliomas and astrocytic gliomas exhibited frequent methylation of MGMT. However, the results of MSP did not completely correspond to that of the immunohistochemical staining for MGMT. The expression of p53 protein was more frequently observed in patients without a 1 p or 19q deletion in anaplastic oligodendrogliomas （=0.032,0.025）. In low-grade oligodendrogliomas, methylation of MGMT was more frequent in patients with 1 p/19q deletion than in patients with 1p/19q intact （P=0.038）. Patients with oligodendrogliomas with 1p/19q loss of heterozygosity and p53-negative showed a longer progression-free survival.Conclusion Detection of chromosome 1p/19q status combined with p53 protein immunohistochemistry might be beneficial to improve the pathological diagnosis and to determine the prognosis of patients with oligodendrogliomas.展开更多
文摘p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37. 5 % (3/8), 42. 11 % (8/19), 53. 33 (16/30) respectively- There was significant dif-ference among groups of metaplasia, dysplasia, cancer and normal controls. Noexon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course ofprecancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6,APC was 47,37 % (9/19), 8. 73% (2/23), 16. 67 % (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis,depth of invasion- LOH of exon4 may be one of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis
文摘Late stage colorectal carcinoma is very complicated in its molecular mechanisms. One hundred andnine cases of colorectal carcinomas were analyzed with RFLP method for the allelic deletion of chromosome 17short arms (ADCC17p) In this study. The results showed that frs(luency of allelic deletion of chromosome 17short arms (FADC17P) in Dukes’ D stage (95 % ) was higher than those in Dukes’ A, B. C stages (54% 68% ); Fisher’s exact test P <0. 01; FADC17p in colorectal carcinomas with distant metastasis (95 % ) washigher than those without distant metastasis, Fisher’s exact test P <0. 01 However, there were no significant differences in FADC 1 7p between the colorectal carcinomas with lymph node metastasis and those without lymph node metastasis (P >0. 05). Therefore, it is considered that ADC17p is an important diagnosticmarker of late stage colorectal carcinomas, and indicates a poor prognosis.
文摘Background Our previous study confirmed that oligodendrogliomas had higher frequency of chromosome 1p/19q deletion. In order to improve the diagnostic criteria and to predict the prognosis of oligodendroglioma patients, the status of chromosome 1 p/19q deletion, the methylation of O6-methylguanine-DNA methyltransferase （MGMT）, and the expression of p53 protein were evaluated and investigated in relation to patients＇ outcomes.Methods Methylation of MGMT in 73 cases was analyzed by nested methylation-specific PCR （MSP）. The levels of MGMT and p53 protein were tested with immunohistochemistry. Pearson＇s chi-square test and Fisher＇s exact test were used. Multivariate and Kaplan-Meier analysis were performed to determine patients＇ outcomes.Results Both oligodendrogliomas and astrocytic gliomas exhibited frequent methylation of MGMT. However, the results of MSP did not completely correspond to that of the immunohistochemical staining for MGMT. The expression of p53 protein was more frequently observed in patients without a 1 p or 19q deletion in anaplastic oligodendrogliomas （=0.032,0.025）. In low-grade oligodendrogliomas, methylation of MGMT was more frequent in patients with 1 p/19q deletion than in patients with 1p/19q intact （P=0.038）. Patients with oligodendrogliomas with 1p/19q loss of heterozygosity and p53-negative showed a longer progression-free survival.Conclusion Detection of chromosome 1p/19q status combined with p53 protein immunohistochemistry might be beneficial to improve the pathological diagnosis and to determine the prognosis of patients with oligodendrogliomas.
