Tumor protein p53 (TP53) mediates DNA repair and cell proliferation in growing cells. The TP53 gene is a tumor suppressor that regulates the expression of target genes in response to multiple cellular stress factors. ...Tumor protein p53 (TP53) mediates DNA repair and cell proliferation in growing cells. The TP53 gene is a tumor suppressor that regulates the expression of target genes in response to multiple cellular stress factors. Key target genes are involved in crucial cellular events such as DNA repair, cell cycle regulation, apoptosis, metabolism, and senescence. TP53 genetic variants and the activity of the wild-type p53 protein (WT-p53) have been linked to a wide range of tumorigenesis. Various genetic and epigenetic alterations, including germline and somatic mutations, loss of heterozygosity, and DNA methylation, can alter TP53 activity, potentially resulting in cancer initiation and progression. This study was designed to screen three reported mutations in the DNA-binding domain of the p53 protein in breast cancer, to evaluate the relative susceptibility and risk associated with breast cancer in the local population. Genomic DNA was isolated from 30 breast tumor tissues along with controls. Tetra and Tri ARMS PCR were performed to detect mutations in the TP53 coding region. For SNPs c.637C>T and c.733C>T, all analyzed cases were homozygous for the wild-type allele ‘C,’ while for SNP c.745A>G, all cases were homozygous for the wild-type allele ‘A.’ These results indicate no relevance of these three SNPs to cancer progression in our study cohort. Additionally, the findings from whole exon sequencing will help to predict more precise outcomes and assess the importance of TP53 gene mutations in breast cancer patients.展开更多
AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors....AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors. METHODS The overexpression and point mutations of tumor suppressor gene p53 in 38 cases of HCC were detected by a sensitive antigen retrieval fluid (ARF) immunohistochemical method and polymerase chain re- action(PCR)-restriction fragment length polymorphism (RFLP),and single strand conformation polymorphism (SSCP)-silver staining analysis. RESULTS The results showed that 16 of 38 HCCs had positive p53 protein (42.1%),7 HCCs had p53 mutation at 249 (18.4 % ) and 2 HCCS had point muta- tion within exon 7 other than 249. Among 9 cases of HCC with mutations,8 cases demonstrated positive p53 protein,its coincidental rate was 88.9%. The overexpression and mutations of p53 were significantly related to the differentiation and metastasis of HCCs. The frequency of p53 mutations was consistent with high prevalence of HBV and a moderate aflatoxin B1 (AFB1) exposure in our area. CONCLUSIONS The results suggest that AFB1 acts synergistically with HBV in the generation of p53 mutations. Furthermore,dietary exposure to AFB1 may mainly contribute to the tumor specific mutation at codon 249,while HBV may account for other scattered mutations in HCC.展开更多
AIMS p53 gene is one of the focuses in the study of tu- mour suppressor genes.So far,there is still controversy about the relationship between p53 alterations and clinicolpathological parameters of gastic cancers such...AIMS p53 gene is one of the focuses in the study of tu- mour suppressor genes.So far,there is still controversy about the relationship between p53 alterations and clinicolpathological parameters of gastic cancers such as macroscopic classifica- tion,stage,degree of differentiation,depth of tumour invasion and lymphonod metastasis.Tamura has reported that p53 gene mutations mainly occur in the aneuploid tumours.But in China, nothing is reported in this field of study.Our aim is to analyze the relationship between p53 gene mutations and these param- eters including DNA ploidy in Chinese primary gasrtic cancers. METHODS Mutations of the p53 gene in exon5-8 were examined in 20 cases of primary gasric cancer by PCR-SSCP (Polymerase-chain-reaction-single-strand-conforma- tion-polymorphism)analysis. RESULTS Mutations were detected in 8(40%)cases:2 cases in exon5-6,2 cases in exon7,4 cases in exon8.These mutations were detected from stage 0 to stage Ⅲ No significant association was found between p53 gene mutations and the clinicopathological parameters such as macroscopic classifico- tion,degree of histological differentiation,depth of tumour in- vasion and lymphonod metastasis.In addition,66.7%(6 of 9) of aneuploid tumours had p53 mutations and only 18.2%(2 of 11)of diploid tumours had mutations. CONCLUSIONS These results suggest that p53 gene muta- tions are related to DNA ploidy alterations and that p53 gene is one of the important turnout suppressor genes in human gastric cancer.展开更多
AIM To study the significance of p53 gene in hepatocarcinogenesis through analyzing codon 249 mutations of p53 gene in non neoplastic liver tissues. METHODS Codon 249 mutation was detected using single st...AIM To study the significance of p53 gene in hepatocarcinogenesis through analyzing codon 249 mutations of p53 gene in non neoplastic liver tissues. METHODS Codon 249 mutation was detected using single stranded conformational polymorphism analysis and allele specific PCR in liver tissues from 10 cases of chronic hepatitis, 5 cases of cirrhosis and 20 cases of HCCs. RESULTS The detection rate of codon 249 mutation in chronic hepatitis, cirrhosis and pericancerous tissues was 70% (7/10), 100% (5/5) and 70% (14/20), respectively by AS PCR. These mutations could not be detected by SSCP analysis. The detection rates were 65% (13/20) and 45% (9/20) in cancerous tissues by AS PCR and SSCP analysis. CONCLUSION Codon 249 mutations of p53 gene were very popular in non neoplastic liver tissues though the number of those mutant cells was only in subsection. Those mutations in cancerous tissues might take place in the stage before the formation of tumor.展开更多
INTRODUCTIONAdenocarcinomas of the cardia are the lesionsarising from the proximal stomach or within 3 cm ofthe gastroesophageal junction.These cancerstended to be advanced at the time of presentation,usually with poo...INTRODUCTIONAdenocarcinomas of the cardia are the lesionsarising from the proximal stomach or within 3 cm ofthe gastroesophageal junction.These cancerstended to be advanced at the time of presentation,usually with poor prognosis.In recent decade,the incidence of adenocarcinoma of gastric eardiaand esophagus are increasing steadily,while therehas been a decrease in the proportion of the cancersarising from the distal stomach.The展开更多
INTRODUCTIONIn order to study the relationship between oncogeneexpression and HCC generation,we observed theprecancerous hepatic GGT loci,IGF-Ⅱ,p53 andp21 expression during hepatocarcinogenesis of treeshrew induced b...INTRODUCTIONIn order to study the relationship between oncogeneexpression and HCC generation,we observed theprecancerous hepatic GGT loci,IGF-Ⅱ,p53 andp21 expression during hepatocarcinogenesis of treeshrew induced by hepatitis B virus (HBV) and/oraflatoxin B1 (AFB1).展开更多
AIM To evaluate the relationship between expression of ras, p53, bcl 2 gene products, and hepatocarcinogenesis since endotoxemia produced from lipopolysaccharide admi nistration and/or the hypophagocytic state of ...AIM To evaluate the relationship between expression of ras, p53, bcl 2 gene products, and hepatocarcinogenesis since endotoxemia produced from lipopolysaccharide admi nistration and/or the hypophagocytic state of splenectomy significantly accelerated hepatocarcinogenesis induced by thioacetamide. 〖WTH4〗METHODS〓〖WTXFZ〗The hepatocarcinoma model was induced by oral intake of 0 03% thioacetamide for six months. During the induction of hepatocarcinoma model, rats were additionally treated with splenectomy and/or lipopolysaccharide administration. The techniques of flow cytometry, immunohistochemistry and immunoelectronmicroscopy were applied to quantitative analysis of the expression of oncogene proteins. RESULTS In this model system, overexpression of ras p21 protein mainly occurred on precancerous cell population or in early stage of hepatocyte transformation. And the levels of ras p21 declined when nuclear DNA aneuploid increased. Expression of bcl 2 protein slowly and steadily rose with more hepatocytes staying in S+G2M phases as the hepatocarcinoma became more malignant. P53 was moderately expressed during the hepatocarcinogenesis. There was no statistical correlation between endotoxemia levels and the changes of ras, p53 and bcl 2 gene products. CONCLUSION Over expression of oncogene ras p21 was likely to be a precursor of the premalignant hepatocytes and it might be responsible for the initiation of hepatocarcinogenesis. Bcl 2 protein expression is proportional to the severity of the malignancies. P53 may be a key pathway on the transformation and development of hepatocarcinoma. This study confirmed the hypothesis that there are multiple genes and multiple steps involved in hepatocarcinogenesis. Expressions of oncogene proteins reflected the properties of the premalignant and malignant cells, but not directly related to endotoxemia statistically.[JP]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
AIM: To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS: A total of 103 gastric cancer patients were included in ...AIM: To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS: A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. We only studied four (exon 5, 6, 7, and 8) of the 11 ,p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters. RESULTS: Among 103 cases, p53 over-expression and alteration were detected in 37 (35.92%) and 19 (18.44%) cases, respectively. Most of the ,p53 alterations were found at exon 5 (31.54%), followed by exon 6 (26.31%), exon 7 (21.04%) and exon 8 (21.04%). A significant correlation of p53 overexpression was found with p53 alteration (P = 0.000). Concordance between ,p53 alteration (as detected by SSCP) and over-expression [as detected by immunohistochemistry (IHC)] was found in 75% cases. We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCP- positive cases accounted for remaining 4% cases. CONCLUSION: Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in over-expression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.展开更多
AIM:To evaluate the efficacy and safety of combination therapy with recombinant adenovirus p53 injection (rAdp53) and transcatheter hepatic arterial chemoembolization (TACE) for advanced hepatocellular carcinoma (HCC)...AIM:To evaluate the efficacy and safety of combination therapy with recombinant adenovirus p53 injection (rAdp53) and transcatheter hepatic arterial chemoembolization (TACE) for advanced hepatocellular carcinoma (HCC).METHODS:A total of 82 patients with advanced HCC treated only with TACE served as control group.Another 68 patients with HCC treated with TACE in combination with recombinant adenovirus-p53 injection served as p53 treatment group.Patients were followed up for 12 mo.Safety and therapeutic effects were evaluated according to the improvement in clinical symptoms,leukocyte count,Karnofsky and RECIST criteria.Survival rate was calculated with Kaplan-Meier method.RESULTS:The total effective rate was 58.3% for p53 treatment group,and 26.5% for control group (P < 0.05).The incidence of gastrointestinal symptoms was lower in p53 treatment group than in control group (P < 0.05).The 3-,6-and 12-mo survival rates were significantly higher for p53 treatment group than for control group (P < 0.01).The combination treatment was well tolerated with such adverse events as fever (51.5%,P=0.006) and pain of muscles and joints (13.2%,P=0.003),which were significantly higher than the chemotherapy.Except for these minor adverse effects,no severe vector-related complications were identified.With respect to the efficacy,patients in p53 treatment group had less gastrointerestinal symptoms (P=0.062),better improvement in tumor-related pain (P=0.003),less downgrade of leukocyte counts (P=0.003) and more upgrade of Karnofsky performance score (P=0.029) than those in control group.The total effective rate (CR + PR) for p53 treatment group and control group was 58.3% and 26.5%,respectively,with distributions of different effect in two groups (P=0.042).The survival rates were 89.71%,76.13%,and 43.30% for p53 treatment group,and 68.15%,36.98%,and 24.02% for control group,respectively,3,6 and 12 mo after treatment,suggesting that the survival rates are significantly higher for p53 treatment group than for control group (P=0.0002).CONCLUSION:The rAd-p53 gene therapy in combination with TACE is a safe and effective treatment modality for advanced HCC.展开更多
Transcatheter arterial chemoembolization (TACE) has become the standard treatment for unresectable hepatocellular carcinoma (HCC). But this method has some shortages. p53 gene, which was found to be mutant in many hum...Transcatheter arterial chemoembolization (TACE) has become the standard treatment for unresectable hepatocellular carcinoma (HCC). But this method has some shortages. p53 gene, which was found to be mutant in many human tumors, has been proved with broadspectrum anti-tumor effects. We reported a 23-year-old patient with recurrent HCC after irregular hepatectomy. The p53 gene was applied to this patient. We injected percutaneously and infused transcatheterally p53 gene (Gendicine, Shenzhen Sibiono Bentech, China) into his recurrent nodules in liver respectively and 4 d later, the patient received TACE therapy. In the 2 mo follow-up, the patient was in good clinical condition with normal liver function and no recurrence was identified. The case report proposed that recurrent HCC could be successfully treated with p53 gene therapy combining TACE.展开更多
AIM: To study the relationship between Helicobacter pylori (H. pylori) and gastric carcinoma and its possible pathogenesis by H. pylori. METHODS: DNEL technique and immunohistochemical technique were used to study the...AIM: To study the relationship between Helicobacter pylori (H. pylori) and gastric carcinoma and its possible pathogenesis by H. pylori. METHODS: DNEL technique and immunohistochemical technique were used to study the state of apoptosis, proliferation and p53 gene expression. A total of 100 gastric mucosal biopsy specimens, including 20 normal mucosa, 30 H. pylori-negative and 30 H. pylori-positive gastric precancerous lesions along with 20 gastric carcinomas were studied. RESULTS: There were several apoptotic cells in the superficial epithelium and a few proliferative cells within the neck of gastric glands, and no p53 protein expression in normal mucosa. In gastric carcinoma, there were few apoptotic cells, while there were a large number of proliferative cells, and expression of p53 protein significantly was increased. In the phase of metaplasia, the apoptotic index (AI, 4.36%+/-1.95%), proliferative index (PI, 19.11%+/-6.79%) and positivity of p53 expression (46.7%) in H. pylori-positive group were higher than those in normal mucosa (P【0.01). AI in H. pylori-positive group was higher than that in H. pylori-negative group (3.81%+/-1.76%), PI in H. pylori-positive group was higher than that in H. pylori-negative group (12.25%+/-5.63%, P【0.01). In the phase of dysplasia, AI (2.31%+/-1.10%) in H. pylori-positive group was lower (3.05%+/-1.29%) than that in H. pylori-negative group, but PI (33.89%+/-11.65%) was significantly higher (22.09+/-8018%, P【0.01). In phases of metaplasia, dysplasia and gastric cancer in the H. pylori-positive group, AIs had an evidently graduall decreasing trend (P【0.01), while PIs had an evidently gradual increasing trend (P【0.05 or P【0.01), and there was also a trend of gradual increase in the expression of p53 gene. CONCLUSION: In the course of the formation of gastric carcinoma, proliferation of gastric mucosa can be greatly increased by H. pylori, and H. pylori can induce apoptosis in the phase of metaplasia, but in the phase of dysplasia H. pylori can inhibit cellular apoptosis. And H. pylori infection can strengthen the expression of mutated p53 gene.展开更多
AIM: To investigate the inhibitory effect of tumor suppressor p33ING1b and its synergy with p53 gene in hepatocellular carcinoma (HCC).METHODS: Recombinant sense and antisense p33ING1b plasmids were transfected into h...AIM: To investigate the inhibitory effect of tumor suppressor p33ING1b and its synergy with p53 gene in hepatocellular carcinoma (HCC).METHODS: Recombinant sense and antisense p33ING1b plasmids were transfected into hepatoma cell line HepG2 with lipofectamine. Apoptosis, G0/G1 arrest, cell growth rate and cloning efficiency in soft agar of HepG2 were analyzed after transfection. In three hepatoma cell lineswith different endogenous p53 gene expressions, the synergistic effect of p33ING1b with p53 was analyzed by flow cytometry and luciferase assay was performed to detect the activation of p53 downstream gene p21WAF1/CIP1. In addition, the expression and mutation rates of p33ING1b in HCC tissues were measured by immunohistochemistry and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP).RESULTS: Overexpression of p33ING1b inhibited cell growth of HepG2, induced more apoptosis and protected cells from growth in soft agar. Combined transfer of p33ING1b and p53 gene promoted hepatoma cell apoptosis, G0/G1 arrest and elevated expression of p21WAF1/CIP1. Immunostaining results showed co-localized P33ING1b with P53 protein in HCC tissues and there was a significant relation between protein expression rates of these two genes (P<0.01).Among 28 HCC samples, p33ING1b presented a low gene mutation rate (7.1%).CONCLUSION: p33ING1b collaborates with p53 in cell growth inhibition, cell cycle arrest and apoptosis in HCC. Loss or inactivation of p33ING1b normal function may be an important mechanism for the development of HCC retaining wildtype p53.展开更多
Hepatocellular carcinoma (HCC) is one of the 10 most common cancers worldwide. There is no ideal treatment for HCC yet and many researchers are trying to improve the effects of treatment by changing therapeutic strate...Hepatocellular carcinoma (HCC) is one of the 10 most common cancers worldwide. There is no ideal treatment for HCC yet and many researchers are trying to improve the effects of treatment by changing therapeutic strategies. As the majority of human cancers seem to exhibit either abnormal p53 gene or disrupted p53 gene activation pathways, intervention to restore wild-type p53 (wt-p53) activities is an attractive anti-cancer therapy including HCC. Abnormalities of p53 are also considered a predisposition factor for hepatocarcinogenesis. p53 is frequently mutated in HCC. Most HCCs have defects in the p53-mediated apoptotic pathway although they carry wt-p53. High expression of p53 in vivo may exert therapeutic effects on HCC in two aspects: (1) High expression of exogenous p53 protein induces apoptosis of tumor cells by inhibiting proliferation of cells through several biologic pathways and (2) Exogenous p53 renders HCC more sensitive to some chemotherapeutic agents. Several approaches have been designed for the treatment of HCC via the p53 pathway by restoring the tumor suppression function from inactivation, rescuing the mutated p53 gene from instability, or delivering therapeutic exogenous p53. Products with p53 status as the target have been studied extensively in vitro and in vivo . This review elaborates some therapeutic mechanisms and advances in using recombinant human adenovirus p53 and oncolytic virus products for the treatment of HCC.展开更多
文摘Tumor protein p53 (TP53) mediates DNA repair and cell proliferation in growing cells. The TP53 gene is a tumor suppressor that regulates the expression of target genes in response to multiple cellular stress factors. Key target genes are involved in crucial cellular events such as DNA repair, cell cycle regulation, apoptosis, metabolism, and senescence. TP53 genetic variants and the activity of the wild-type p53 protein (WT-p53) have been linked to a wide range of tumorigenesis. Various genetic and epigenetic alterations, including germline and somatic mutations, loss of heterozygosity, and DNA methylation, can alter TP53 activity, potentially resulting in cancer initiation and progression. This study was designed to screen three reported mutations in the DNA-binding domain of the p53 protein in breast cancer, to evaluate the relative susceptibility and risk associated with breast cancer in the local population. Genomic DNA was isolated from 30 breast tumor tissues along with controls. Tetra and Tri ARMS PCR were performed to detect mutations in the TP53 coding region. For SNPs c.637C>T and c.733C>T, all analyzed cases were homozygous for the wild-type allele ‘C,’ while for SNP c.745A>G, all cases were homozygous for the wild-type allele ‘A.’ These results indicate no relevance of these three SNPs to cancer progression in our study cohort. Additionally, the findings from whole exon sequencing will help to predict more precise outcomes and assess the importance of TP53 gene mutations in breast cancer patients.
文摘AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors. METHODS The overexpression and point mutations of tumor suppressor gene p53 in 38 cases of HCC were detected by a sensitive antigen retrieval fluid (ARF) immunohistochemical method and polymerase chain re- action(PCR)-restriction fragment length polymorphism (RFLP),and single strand conformation polymorphism (SSCP)-silver staining analysis. RESULTS The results showed that 16 of 38 HCCs had positive p53 protein (42.1%),7 HCCs had p53 mutation at 249 (18.4 % ) and 2 HCCS had point muta- tion within exon 7 other than 249. Among 9 cases of HCC with mutations,8 cases demonstrated positive p53 protein,its coincidental rate was 88.9%. The overexpression and mutations of p53 were significantly related to the differentiation and metastasis of HCCs. The frequency of p53 mutations was consistent with high prevalence of HBV and a moderate aflatoxin B1 (AFB1) exposure in our area. CONCLUSIONS The results suggest that AFB1 acts synergistically with HBV in the generation of p53 mutations. Furthermore,dietary exposure to AFB1 may mainly contribute to the tumor specific mutation at codon 249,while HBV may account for other scattered mutations in HCC.
文摘AIMS p53 gene is one of the focuses in the study of tu- mour suppressor genes.So far,there is still controversy about the relationship between p53 alterations and clinicolpathological parameters of gastic cancers such as macroscopic classifica- tion,stage,degree of differentiation,depth of tumour invasion and lymphonod metastasis.Tamura has reported that p53 gene mutations mainly occur in the aneuploid tumours.But in China, nothing is reported in this field of study.Our aim is to analyze the relationship between p53 gene mutations and these param- eters including DNA ploidy in Chinese primary gasrtic cancers. METHODS Mutations of the p53 gene in exon5-8 were examined in 20 cases of primary gasric cancer by PCR-SSCP (Polymerase-chain-reaction-single-strand-conforma- tion-polymorphism)analysis. RESULTS Mutations were detected in 8(40%)cases:2 cases in exon5-6,2 cases in exon7,4 cases in exon8.These mutations were detected from stage 0 to stage Ⅲ No significant association was found between p53 gene mutations and the clinicopathological parameters such as macroscopic classifico- tion,degree of histological differentiation,depth of tumour in- vasion and lymphonod metastasis.In addition,66.7%(6 of 9) of aneuploid tumours had p53 mutations and only 18.2%(2 of 11)of diploid tumours had mutations. CONCLUSIONS These results suggest that p53 gene muta- tions are related to DNA ploidy alterations and that p53 gene is one of the important turnout suppressor genes in human gastric cancer.
文摘AIM To study the significance of p53 gene in hepatocarcinogenesis through analyzing codon 249 mutations of p53 gene in non neoplastic liver tissues. METHODS Codon 249 mutation was detected using single stranded conformational polymorphism analysis and allele specific PCR in liver tissues from 10 cases of chronic hepatitis, 5 cases of cirrhosis and 20 cases of HCCs. RESULTS The detection rate of codon 249 mutation in chronic hepatitis, cirrhosis and pericancerous tissues was 70% (7/10), 100% (5/5) and 70% (14/20), respectively by AS PCR. These mutations could not be detected by SSCP analysis. The detection rates were 65% (13/20) and 45% (9/20) in cancerous tissues by AS PCR and SSCP analysis. CONCLUSION Codon 249 mutations of p53 gene were very popular in non neoplastic liver tissues though the number of those mutant cells was only in subsection. Those mutations in cancerous tissues might take place in the stage before the formation of tumor.
文摘INTRODUCTIONAdenocarcinomas of the cardia are the lesionsarising from the proximal stomach or within 3 cm ofthe gastroesophageal junction.These cancerstended to be advanced at the time of presentation,usually with poor prognosis.In recent decade,the incidence of adenocarcinoma of gastric eardiaand esophagus are increasing steadily,while therehas been a decrease in the proportion of the cancersarising from the distal stomach.The
基金the National Natural Science Foundation of China,No.39260033.
文摘INTRODUCTIONIn order to study the relationship between oncogeneexpression and HCC generation,we observed theprecancerous hepatic GGT loci,IGF-Ⅱ,p53 andp21 expression during hepatocarcinogenesis of treeshrew induced by hepatitis B virus (HBV) and/oraflatoxin B1 (AFB1).
文摘AIM To evaluate the relationship between expression of ras, p53, bcl 2 gene products, and hepatocarcinogenesis since endotoxemia produced from lipopolysaccharide admi nistration and/or the hypophagocytic state of splenectomy significantly accelerated hepatocarcinogenesis induced by thioacetamide. 〖WTH4〗METHODS〓〖WTXFZ〗The hepatocarcinoma model was induced by oral intake of 0 03% thioacetamide for six months. During the induction of hepatocarcinoma model, rats were additionally treated with splenectomy and/or lipopolysaccharide administration. The techniques of flow cytometry, immunohistochemistry and immunoelectronmicroscopy were applied to quantitative analysis of the expression of oncogene proteins. RESULTS In this model system, overexpression of ras p21 protein mainly occurred on precancerous cell population or in early stage of hepatocyte transformation. And the levels of ras p21 declined when nuclear DNA aneuploid increased. Expression of bcl 2 protein slowly and steadily rose with more hepatocytes staying in S+G2M phases as the hepatocarcinoma became more malignant. P53 was moderately expressed during the hepatocarcinogenesis. There was no statistical correlation between endotoxemia levels and the changes of ras, p53 and bcl 2 gene products. CONCLUSION Over expression of oncogene ras p21 was likely to be a precursor of the premalignant hepatocytes and it might be responsible for the initiation of hepatocarcinogenesis. Bcl 2 protein expression is proportional to the severity of the malignancies. P53 may be a key pathway on the transformation and development of hepatocarcinoma. This study confirmed the hypothesis that there are multiple genes and multiple steps involved in hepatocarcinogenesis. Expressions of oncogene proteins reflected the properties of the premalignant and malignant cells, but not directly related to endotoxemia statistically.[JP]
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.
文摘AIM: To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS: A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. We only studied four (exon 5, 6, 7, and 8) of the 11 ,p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters. RESULTS: Among 103 cases, p53 over-expression and alteration were detected in 37 (35.92%) and 19 (18.44%) cases, respectively. Most of the ,p53 alterations were found at exon 5 (31.54%), followed by exon 6 (26.31%), exon 7 (21.04%) and exon 8 (21.04%). A significant correlation of p53 overexpression was found with p53 alteration (P = 0.000). Concordance between ,p53 alteration (as detected by SSCP) and over-expression [as detected by immunohistochemistry (IHC)] was found in 75% cases. We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCP- positive cases accounted for remaining 4% cases. CONCLUSION: Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in over-expression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.
文摘AIM:To evaluate the efficacy and safety of combination therapy with recombinant adenovirus p53 injection (rAdp53) and transcatheter hepatic arterial chemoembolization (TACE) for advanced hepatocellular carcinoma (HCC).METHODS:A total of 82 patients with advanced HCC treated only with TACE served as control group.Another 68 patients with HCC treated with TACE in combination with recombinant adenovirus-p53 injection served as p53 treatment group.Patients were followed up for 12 mo.Safety and therapeutic effects were evaluated according to the improvement in clinical symptoms,leukocyte count,Karnofsky and RECIST criteria.Survival rate was calculated with Kaplan-Meier method.RESULTS:The total effective rate was 58.3% for p53 treatment group,and 26.5% for control group (P < 0.05).The incidence of gastrointestinal symptoms was lower in p53 treatment group than in control group (P < 0.05).The 3-,6-and 12-mo survival rates were significantly higher for p53 treatment group than for control group (P < 0.01).The combination treatment was well tolerated with such adverse events as fever (51.5%,P=0.006) and pain of muscles and joints (13.2%,P=0.003),which were significantly higher than the chemotherapy.Except for these minor adverse effects,no severe vector-related complications were identified.With respect to the efficacy,patients in p53 treatment group had less gastrointerestinal symptoms (P=0.062),better improvement in tumor-related pain (P=0.003),less downgrade of leukocyte counts (P=0.003) and more upgrade of Karnofsky performance score (P=0.029) than those in control group.The total effective rate (CR + PR) for p53 treatment group and control group was 58.3% and 26.5%,respectively,with distributions of different effect in two groups (P=0.042).The survival rates were 89.71%,76.13%,and 43.30% for p53 treatment group,and 68.15%,36.98%,and 24.02% for control group,respectively,3,6 and 12 mo after treatment,suggesting that the survival rates are significantly higher for p53 treatment group than for control group (P=0.0002).CONCLUSION:The rAd-p53 gene therapy in combination with TACE is a safe and effective treatment modality for advanced HCC.
文摘Transcatheter arterial chemoembolization (TACE) has become the standard treatment for unresectable hepatocellular carcinoma (HCC). But this method has some shortages. p53 gene, which was found to be mutant in many human tumors, has been proved with broadspectrum anti-tumor effects. We reported a 23-year-old patient with recurrent HCC after irregular hepatectomy. The p53 gene was applied to this patient. We injected percutaneously and infused transcatheterally p53 gene (Gendicine, Shenzhen Sibiono Bentech, China) into his recurrent nodules in liver respectively and 4 d later, the patient received TACE therapy. In the 2 mo follow-up, the patient was in good clinical condition with normal liver function and no recurrence was identified. The case report proposed that recurrent HCC could be successfully treated with p53 gene therapy combining TACE.
基金Supported by National Ninth Five-Year Study Program for Tacking Key Scientific Problems.No.96-906-01-04
文摘AIM: To study the relationship between Helicobacter pylori (H. pylori) and gastric carcinoma and its possible pathogenesis by H. pylori. METHODS: DNEL technique and immunohistochemical technique were used to study the state of apoptosis, proliferation and p53 gene expression. A total of 100 gastric mucosal biopsy specimens, including 20 normal mucosa, 30 H. pylori-negative and 30 H. pylori-positive gastric precancerous lesions along with 20 gastric carcinomas were studied. RESULTS: There were several apoptotic cells in the superficial epithelium and a few proliferative cells within the neck of gastric glands, and no p53 protein expression in normal mucosa. In gastric carcinoma, there were few apoptotic cells, while there were a large number of proliferative cells, and expression of p53 protein significantly was increased. In the phase of metaplasia, the apoptotic index (AI, 4.36%+/-1.95%), proliferative index (PI, 19.11%+/-6.79%) and positivity of p53 expression (46.7%) in H. pylori-positive group were higher than those in normal mucosa (P【0.01). AI in H. pylori-positive group was higher than that in H. pylori-negative group (3.81%+/-1.76%), PI in H. pylori-positive group was higher than that in H. pylori-negative group (12.25%+/-5.63%, P【0.01). In the phase of dysplasia, AI (2.31%+/-1.10%) in H. pylori-positive group was lower (3.05%+/-1.29%) than that in H. pylori-negative group, but PI (33.89%+/-11.65%) was significantly higher (22.09+/-8018%, P【0.01). In phases of metaplasia, dysplasia and gastric cancer in the H. pylori-positive group, AIs had an evidently graduall decreasing trend (P【0.01), while PIs had an evidently gradual increasing trend (P【0.05 or P【0.01), and there was also a trend of gradual increase in the expression of p53 gene. CONCLUSION: In the course of the formation of gastric carcinoma, proliferation of gastric mucosa can be greatly increased by H. pylori, and H. pylori can induce apoptosis in the phase of metaplasia, but in the phase of dysplasia H. pylori can inhibit cellular apoptosis. And H. pylori infection can strengthen the expression of mutated p53 gene.
基金Supported by the National Natural Science Foundation of China (Grants No.30070344 and No.30070839)
文摘AIM: To investigate the inhibitory effect of tumor suppressor p33ING1b and its synergy with p53 gene in hepatocellular carcinoma (HCC).METHODS: Recombinant sense and antisense p33ING1b plasmids were transfected into hepatoma cell line HepG2 with lipofectamine. Apoptosis, G0/G1 arrest, cell growth rate and cloning efficiency in soft agar of HepG2 were analyzed after transfection. In three hepatoma cell lineswith different endogenous p53 gene expressions, the synergistic effect of p33ING1b with p53 was analyzed by flow cytometry and luciferase assay was performed to detect the activation of p53 downstream gene p21WAF1/CIP1. In addition, the expression and mutation rates of p33ING1b in HCC tissues were measured by immunohistochemistry and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP).RESULTS: Overexpression of p33ING1b inhibited cell growth of HepG2, induced more apoptosis and protected cells from growth in soft agar. Combined transfer of p33ING1b and p53 gene promoted hepatoma cell apoptosis, G0/G1 arrest and elevated expression of p21WAF1/CIP1. Immunostaining results showed co-localized P33ING1b with P53 protein in HCC tissues and there was a significant relation between protein expression rates of these two genes (P<0.01).Among 28 HCC samples, p33ING1b presented a low gene mutation rate (7.1%).CONCLUSION: p33ING1b collaborates with p53 in cell growth inhibition, cell cycle arrest and apoptosis in HCC. Loss or inactivation of p33ING1b normal function may be an important mechanism for the development of HCC retaining wildtype p53.
文摘Hepatocellular carcinoma (HCC) is one of the 10 most common cancers worldwide. There is no ideal treatment for HCC yet and many researchers are trying to improve the effects of treatment by changing therapeutic strategies. As the majority of human cancers seem to exhibit either abnormal p53 gene or disrupted p53 gene activation pathways, intervention to restore wild-type p53 (wt-p53) activities is an attractive anti-cancer therapy including HCC. Abnormalities of p53 are also considered a predisposition factor for hepatocarcinogenesis. p53 is frequently mutated in HCC. Most HCCs have defects in the p53-mediated apoptotic pathway although they carry wt-p53. High expression of p53 in vivo may exert therapeutic effects on HCC in two aspects: (1) High expression of exogenous p53 protein induces apoptosis of tumor cells by inhibiting proliferation of cells through several biologic pathways and (2) Exogenous p53 renders HCC more sensitive to some chemotherapeutic agents. Several approaches have been designed for the treatment of HCC via the p53 pathway by restoring the tumor suppression function from inactivation, rescuing the mutated p53 gene from instability, or delivering therapeutic exogenous p53. Products with p53 status as the target have been studied extensively in vitro and in vivo . This review elaborates some therapeutic mechanisms and advances in using recombinant human adenovirus p53 and oncolytic virus products for the treatment of HCC.