Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissu...Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissues of sixteen PHC cases were studied by Southern hybridization to detect the state of HBV-DNA in tissues, byimmunohistochemical staining to determine HBsAg, HBxAg and p53 protein, and by PCR directed sequencing toanalyse the point mutation of p53 gene exons 5 to 8. Results: Among the 16 cases. 13 cases were HBV-DNA posi-tive, 10 tumor cases and 13 nontumor tissues cases HBxAg positive, and 9 cases posltive for p53 protein. The se-quencing of p53 gene point mutation was found in 5 cases, only one of which was sited at codon 249 G to T. Con-clusion: The mutation of p53 gene codon 249 is infrequent in HBV related PHC,indicating the accumulation of p53protein in cells may be associated with expression of HBxAg. HBxAg binding to p53 protein and inactivation of p53function play important roles in the development of PHC.展开更多
AIM To study the correlationship between the changes of p53, Waf1p21 and the cell proliferation determined by PCNA at different stages of human esophageal carcinogenesis. METHODS Biopsied and resected esophageal ti...AIM To study the correlationship between the changes of p53, Waf1p21 and the cell proliferation determined by PCNA at different stages of human esophageal carcinogenesis. METHODS Biopsied and resected esophageal tissues from a high risk population for esophageal cancer in northern China were used in this study. All the specimens were fixed with 85% alcohol and further processed with routine histology. The avidin biotin peroxidase complex (ABC) method was used for the detection of p53, Waf1p21 and PCNA. RESULTS The strong nuclear staining for p53, Waf1p21 and PCNA was observed in the normal esophageal epithelium and the epithelia with different severities of lesions. As the lesions progressed to dysplasia (DYS) and to esophageal squamons cell carcinoma (SCC), the percentage of Waf1p21 immunoreactivity decreased. The number of Waf1p21 immunostaining positive cells increased slightly from normal to basal cell hyperplasia (BCH), but there was no further increase in DYS and in SCC. The total number of positive cells for Waf1p21 stain appeared to be lower than that of p53 in normal and BCH esophageal epithelia and much lower in DYS and SCC. The Waf1p21 positive immunostaining cells were located at the third and forth cell layers in half of the samples examined, which was 2～4 cell layers higher than that of PCNA and p53 in the same histological categories of normal, BCH and DYS. CLNCLUSION The low levels of Waf1p21 at the stage of DYS may be related to a functional loss of p53. Other mechanisms may also be responsible to the lack of Waf1p21 expression in DYS and SCC.展开更多
文摘Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissues of sixteen PHC cases were studied by Southern hybridization to detect the state of HBV-DNA in tissues, byimmunohistochemical staining to determine HBsAg, HBxAg and p53 protein, and by PCR directed sequencing toanalyse the point mutation of p53 gene exons 5 to 8. Results: Among the 16 cases. 13 cases were HBV-DNA posi-tive, 10 tumor cases and 13 nontumor tissues cases HBxAg positive, and 9 cases posltive for p53 protein. The se-quencing of p53 gene point mutation was found in 5 cases, only one of which was sited at codon 249 G to T. Con-clusion: The mutation of p53 gene codon 249 is infrequent in HBV related PHC,indicating the accumulation of p53protein in cells may be associated with expression of HBxAg. HBxAg binding to p53 protein and inactivation of p53function play important roles in the development of PHC.
文摘AIM To study the correlationship between the changes of p53, Waf1p21 and the cell proliferation determined by PCNA at different stages of human esophageal carcinogenesis. METHODS Biopsied and resected esophageal tissues from a high risk population for esophageal cancer in northern China were used in this study. All the specimens were fixed with 85% alcohol and further processed with routine histology. The avidin biotin peroxidase complex (ABC) method was used for the detection of p53, Waf1p21 and PCNA. RESULTS The strong nuclear staining for p53, Waf1p21 and PCNA was observed in the normal esophageal epithelium and the epithelia with different severities of lesions. As the lesions progressed to dysplasia (DYS) and to esophageal squamons cell carcinoma (SCC), the percentage of Waf1p21 immunoreactivity decreased. The number of Waf1p21 immunostaining positive cells increased slightly from normal to basal cell hyperplasia (BCH), but there was no further increase in DYS and in SCC. The total number of positive cells for Waf1p21 stain appeared to be lower than that of p53 in normal and BCH esophageal epithelia and much lower in DYS and SCC. The Waf1p21 positive immunostaining cells were located at the third and forth cell layers in half of the samples examined, which was 2～4 cell layers higher than that of PCNA and p53 in the same histological categories of normal, BCH and DYS. CLNCLUSION The low levels of Waf1p21 at the stage of DYS may be related to a functional loss of p53. Other mechanisms may also be responsible to the lack of Waf1p21 expression in DYS and SCC.
