To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on ch...To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular展开更多
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
Objective: To evaluate the effect of adenovirus-mediated p53 gene (Adp53) on apoptosis andradiosensitivity of human gastric carcinoma cell lines.Methods: Recombinant adenovirus expressing wild-type p53 gene was transf...Objective: To evaluate the effect of adenovirus-mediated p53 gene (Adp53) on apoptosis andradiosensitivity of human gastric carcinoma cell lines.Methods: Recombinant adenovirus expressing wild-type p53 gene was transferred into four human gastric carcinoma cell lines with different p53 genetic status. p53 proteinexpression was detected by immunohistochemistry assayand western blot assay. Cell survival was assessed using a clonogenic assay. TUNEL assay was used in determination of apoptosis. Four human gastric carcinoma cells infectedwith Adp53 were irradiated with 4Gy and cell cycle distribution and Sub-G1 peak were assayed by flowcytometry. Results: G2/M arrest, apoptosis and inhibition of tumor cell proliferation were induced by infection atAdp53 at 100 MOI which caused high transfer rate ofwild-type p53 and strong expression of p53 protein in four human gastric carcinoma cells. The radio-enhancement ratio of Adp53 at 4Gy were 3.0 for W cell, 3.6 for M cell, 2.2 for neo cell and 2.5 for 823 cell in vitro. Conclusion: Thisstudy demonstrated that Adp53 transfer increased cellularapoptosis and radiosensitivity of human gastric carcinoma cell lines in vitro independently on cellular intrinsic p53status thus supporting the combination of p53 gene therapy with radiotherapy in clinical trials.展开更多
Objective: To study the effect of Shugan Shuru Granule (疏肝舒乳颗粒,SSG) on the p53 gene expression in patients with hyperplastic disease of breast (HDB) to indirectly explore the mechanism of SSG’s effect on HDB on...Objective: To study the effect of Shugan Shuru Granule (疏肝舒乳颗粒,SSG) on the p53 gene expression in patients with hyperplastic disease of breast (HDB) to indirectly explore the mechanism of SSG’s effect on HDB on the molecular pathological level. Methods: Sixty-six patients with HDB were allocated in the treated group and the control group,with the former treated with SSG and the latter not. All patients underwent breast operation and their diseased mammary tissues were cut out, sectioned, and observed under microscopy with HE staining and immunohistochemical staining, with ABC method adopted to estimate the degree of hyperplasia and p53 gene expression. The severity of HDB was classified into normal, mild, moderate and severe grades (marked as 0 to Ⅲ), according to the degree of hyperplasia in the mammary gland. Results: Hyperplasia in the control group mostly belonged to grade Ⅰ-Ⅲ before treatment, showing overgrowth of gland and proliferation of glandular epithelial cells, which were high columnar shaped, more stratified, with papillary or substantive dysplasia. While in the treated group, most belonged to grade 0-Ⅰ after SSG treatment, with proliferated gland and dysplasia recovered to normal or disappeared. The positive rate of p53 gene expression in the treated group was 9.09%, and in the control group 39.39%, comparison between the two groups showing significant difference (P<0.01), the intensity in the former was significantly weaker than that in the latter.Conclusion: SSG could not only inhibit the proliferation of mammary duct epithelia and lobuli, but also inhibit the over-expression of P53. Therefore, it could be regarded as an effective remedy for treatment of HDB and prevention of mammary cancer genesis.展开更多
BACKGROUND: Current studies related to the effects of proanthocyanidins on Alzheimer's disease have focused primarily on the signal transduction pathway of cellular apoptosis. However, the influence of p53 gene expr...BACKGROUND: Current studies related to the effects of proanthocyanidins on Alzheimer's disease have focused primarily on the signal transduction pathway of cellular apoptosis. However, the influence of p53 gene expression on cell cycle regulation, with regard to the protective mechanisms of proanthocyanidins, has not been reported. OBJECTIVE: To observe the effect of proanthocyanidins on cell cycle distribution, cellular apoptosis and p53 gene expression in β-amyloid peptide (25-35) (Aβ25-35)-induced PC12 cells cultured in serum-free media, and to investigate the molecular neuroprotective mechanisms of proanthocyanidins with regard to cell cycle regulation. DESIGN, TIME AND SETTING: A parallel, controlled, at the Institute of Biochemistry and Molecular Biology cellular, and molecular study was performed Guangdong Medical College from July 2006 to July 2008. MATERIALS: Proanthocyanidins were provided by Nanjing Xuezi Medical and Chemical Research Center, China; Aβ25-35 was provided by Sigma, USA; PC12 cells were provided by the Institute of Basic Medical Science, Academy of Military Medical Sciences; and rabbit anti-p53 polyclonal antibody was provided by Santa Cruz Biotechnology, USA. METHODS: PC12 cells were cultured in serum-free media for 24 hours. Cells from the model group were treated with 25 μmol/L Aβ25-35 for 24 hours. Cells in the drug protection group were pre-treated with 30 mg/L proanthocyanidins for 1 hour and then treated with 25 μmol/LAβ2^-35 for 24 hours. The control group was not treated. MAIN OUTCOME MEASURES: Flow cytometry was used to detect cell cycle distribution and rate of apoptosis; reverse-transcriptase polymerase chain reaction was used to detect p53 mRNA expression; and Western blot was used to detect p53 protein expression. RESULTS: After treating with 25 μmol/LAβ25-35 for 24 hours, the rate of apoptosis and the percentage of cells in S phase were significantly increased (P 〈 0.01 ), and p53 mRNA and protein expressions were decreased. Pretreatment with proanthocyanidins for 1 hour blocked the increase in apoptosis and the percentage of cells in S phase in Aβ25-35-induced PC12 cells (P 〈 0.01 ) and increased p53 mRNA and protein expressions. CONCLUSION: Proanthocyanidins blocked apoptosis and S-phase arrest in Aβ25-35-induced PC12 cells cultured in serum-free media. The protective mechanism could be related to increased p53 mRNA and protein expressions.展开更多
gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and...gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and to approach the mechanism of infiltration and metastasis of gastric carcinoma. The results showed that nuclear expression of p53 protein was significantly related to tumor size, depth of invasion, lymph node and liver metastases; but not related to histological differentiation. It is suggested that the accumulation of p53 protein was increased with the progression of gastric carcinoma, and therefore the cancer clone with p53 gene mutation may play an important role in the development of tumor invasion and metastasis.展开更多
By southern hybridization with 1. 8 kb cDNA probe,a high frequency (40. 5 % ) of structural abnor- mality of p53 gene was observed in primary nasopharyngeal carcinoma (NPC) biopsies. The regions of ex- ons 1 to 4 ...By southern hybridization with 1. 8 kb cDNA probe,a high frequency (40. 5 % ) of structural abnor- mality of p53 gene was observed in primary nasopharyngeal carcinoma (NPC) biopsies. The regions of ex- ons 1 to 4 of the gene were examined by polymerase chain reaction-single strand con formation polymor- phism,no point mutation was found. Because very low rate of point mutation had been reported in exons 5 to 8, we considered that structural abnormality in the region of e-cons 1 to 8 of the gene might be uncom- mon in NPC. The spectrophotometer scanning analysis of autoradiograms and rehybridization investigation of nitrocellulose filter with exon 11 probe indicated that most of structure aberrations we observed might be rearrangement occurring in exon 11.展开更多
BACKGROUND: It is of significance for single nucleotide polymorphisms (SNPs), a difference of rank, which exists widely in biology, genetics and other fields. OBJECTIVE: To detect polymorphism sites in exon-4 of p...BACKGROUND: It is of significance for single nucleotide polymorphisms (SNPs), a difference of rank, which exists widely in biology, genetics and other fields. OBJECTIVE: To detect polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province. DESIGN: Simple random sampling. SETTING: Department of Surgery of the 118 Hospital of Chinese PLA.PARTICIPANTS: A total of 80 healthy people in Han nationality were selected from hospitals in Zhejiang province from August 2005 to January 2006. There were 43 males and 37 females aged from 3 to 78 years with the mean age of 39.5 years, and all subjects were consent. DNA which was used in genetic analysis was selected from peripheral venous blood of all subjects and maintained at -20℃.METHODS: Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene were detected with directly DNA sequencing technique. MAIN OUTCOME MEASURES : Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province. RESULTS: A total of 80 samples were involved in the final analysis. SNPs sites were found at the 119^th base of exon-4 of p53 gene (the 72^nd codon of p53 gene), the 670^th base of upper start codon in promotor of Fas gene (Fas-670), and the 995^th base of intron-7 of Fas gene, especially SNPs in the 995^th base of intron-7 pf Fas gene, i.e. C→A transversion, was a new site.CONCLUSION : One unknown SNPs site is discovered in intron-7 of Fas gene of people in Han nationality in Zhejiang province. This study also proves that the 72^nd codon exists in p53 gene and the -670 polymorphism site exists in promotor of Fas gene.展开更多
转录调节蛋白TP 53(Tumor protein 53)调控多种重要生物学过程,包括细胞周期、DNA损伤、修复和细胞凋亡等.在各种应激条件下tp53会被激活并发挥与应激相关的调控作用,但tp53在鱼类低温应激下的作用尚不明了.本文首先检测在低温应激条件...转录调节蛋白TP 53(Tumor protein 53)调控多种重要生物学过程,包括细胞周期、DNA损伤、修复和细胞凋亡等.在各种应激条件下tp53会被激活并发挥与应激相关的调控作用,但tp53在鱼类低温应激下的作用尚不明了.本文首先检测在低温应激条件下斑马鱼(Danio rerio)中tp53的表达变化,然后利用tp53^(-/-)斑马鱼敲除模型研究了敲除tp53对斑马鱼低温耐受能力和运动的影响.RT-qPCR结果显示:在8℃低温条件下野生型斑马鱼全鱼和鳃组织中tp53的mRNA水平显著升高.低温耐受实验显示:8℃低温下tp53^(-/-)斑马鱼的耐受能力增强,半数致死时间(lethal time to 50%mortality, LT50)显著高于WT(Wild type)对照组(P<0.000 1).运动行为学实验发现:与28℃相比,18℃低温下WT和tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著降低(P<0.000 1);同时发现在28℃和18℃条件下,tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著高于WT组.研究结果说明tp53参与斑马鱼的低温响应过程,敲除tp53后斑马鱼的耐寒能力与运动能力增强.本文为鱼类的低温耐受机制和运动行为学研究提供了新思路.展开更多
Objective: In most laryngeal cancers, the function of p53 gene is down regulated. To explore the potential use of p53 in gene therapy of laryngeal cancer, by introducing wild-type p53 into laryngeal cancer cell line v...Objective: In most laryngeal cancers, the function of p53 gene is down regulated. To explore the potential use of p53 in gene therapy of laryngeal cancer, by introducing wild-type p53 into laryngeal cancer cell line via a recombinant adenoviral vector, Ad5CMV-p53 and analyzing its effects on cell and tumor growth. Methods: A human laryngeal cancer, cell line Hep-2 was used. Recombinant cytomegalovirus-promoted adenoviruses containing human wild-type p53 cDNA was transiently introduced into Hep-2 line. The growth suppression of the Hep-2 cells and established s.c. squamous, carcinoma model was examined. The p53 protein expression was detected using immunohistochemical analysis. Results: The transduction efficiencies of Hep-2 cell line were 100% at a multiplicity of 100 or greater. The p53 protein expression peaked on day 2 after infection and lasted far 5 days. In vitro growth assays revealed cell death following Ad5CMV-p53 infected. In vivo studies, Ad5CMV-p53 inhibited the tumorigenicity of Hep-2 cell, and in nude mice with established s.c. squamous, carcinoma, nodules showed that tumor volumes were significantly reduced in mice that received peritumoral infiltration of Ad5CMV-p53. Conclusion: Adenovirus-mediated antitumor therapy carrying the p53 gene is an efficient method to inhibit laryngeal cancer growth. Transfection of laryngeal cancer cells with the wild-type p53 gene via Ad5CMV-p53 is a potential novel approach to the therapy of laryngeal cancer.展开更多
Objective: To determine the feasibility of detecting p53 gene mutations for early diagnosis of lung cancer using the samples from bronchoscopic examination. Methods: Point mutations of the exon 5-8 of p53 gene were de...Objective: To determine the feasibility of detecting p53 gene mutations for early diagnosis of lung cancer using the samples from bronchoscopic examination. Methods: Point mutations of the exon 5-8 of p53 gene were detected in 85 bronchoscopic samples of 35 patients suspected to be lung cancer using silver staining PCR-SSCP. Results: p53 gene mutations were founded in 10 of 35 patients(28.6%). The incidence of p53 gene mutations (14.9%) was obviously higher than the cytological positive incidence(2.9%) in samples of sputum, bronchoalveolar lavage and brush, especially for the sputum(27.7%). In the bronchoscopic biopsy specimens, the incidence of p53 gene mutations (12.5%) was lower than that of pathologic positive result (50.0%). However, in view of all the bronchoscopic samples, there was no statistically difference between cytopathologic positive results (11.8%) and the incidence of p53 gene mutations (14.1%). Although the p53 mutations were most common in the samples from the patients bronchoscopically manifested as neoplasm compared with other manifestations, there was no statistical difference. It is valuable to notice that 3 patients with p53 gene mutation merely presented as bronchial inflammation in bronchoscope. Conclusion: Results indicated that the value of detecting p53 gene mutation for the diagnosis of lung cancer using the bronchoscopic samples was more superior to cytological examination and detection of p53 gene mutations in post-bronchoscopic sputum was easy and effective, may be used as a valuable method for early diagnosis of lung cancer.展开更多
Summary: To evaluate the effect of wild type p53 gene on the growth and radiotherapeutic sensitivity of human glioma cells, plasmid PC53 SN3 carrying wild type p53 gene was transfected into U251 cells, p53 gene expre...Summary: To evaluate the effect of wild type p53 gene on the growth and radiotherapeutic sensitivity of human glioma cells, plasmid PC53 SN3 carrying wild type p53 gene was transfected into U251 cells, p53 gene expression in transfected cells was detected by RT PCR, and the cell growth inhibition and apoptosis in the absence or presence of irradiation were assessed by MTT and flow cytometry. The transfection of p53 gene into U251 cells was confirmed by RT PCR. MTT showed that p53 gene alone induced strong inhibitory effect on the growth of U251 cells (inhibition rate (IR): (79.60±5.69)%), The killing effect of irradiation alone on U251 cells was not strong (IR: (17. 06±4.35)%, (17.39±1.67)%, (18.73±4.68)%) and increased with the irradiation doses (3, 6, 9 Gy). When combined treatment of wild-type p53 gene transfection and irradiation was used, the effect was significantly increased (IR:(80.60±5.35)%, (90.30+1.67) %, (91.30±2.01) %). Theapoptosis rate of U251 cells induced by p53 gene transfectionwas 17.38 %. The rate induced by irradiation increased (4. 61%, 4. 84%, 5. 40 %) with the irradiation doses (3, 6, 9 Gy). Theapoptosis rate was also significantly increased (17.80%, 20.03%, 22.34%) after combined treatment of p53 and irradiation with different doses (3, 6, 9 Gy). It is concluded that wildtype p53 gene and irradiation could result in synergistic inhibitory effect on the growth of human glioma cells.展开更多
Using a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) approach we analyzed 18 human colorectal adenocarcinomas for mutations in exons 5,6,7,8 of p53 gene. At the same time,p53 gene produ...Using a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) approach we analyzed 18 human colorectal adenocarcinomas for mutations in exons 5,6,7,8 of p53 gene. At the same time,p53 gene product expression was studied immunohistochemically in these 18 case in frozen sections. The expression of p53 protein was also immunohistochemically studied in formalin-fixed paraffin embeded spccimens of 76 colorectal adenocarcinomas and 112colorectal polyps. Eigbt out of 18 cases (44%) showed a variant band indicative of a mutation in exons 5-6 of p53gene 7 out of 8 cascs (88%) with p53 gene mutations were positivelystanined for P53. There was no significant correlation between p53. expression and clinicopathological manifestations and prognosis. but the strongest staining was cncountered in those cases with well differentiated and early stage adenocarcinomas,while weaker staining was encountered in Poorly differentiated and mucoid adenotarcinomas. p53expression was not observed in proliferative polyps and adenomas with low grade dysplasia. The frequency of p53expression reached 88% (p<0.001) when adenoma showed malignant change. Aiuong three types of adenomas, p53 expression was most frequent in villous type (P<0.05). The frequencies of p53 expression in adenoma, adenoma with malignant change and adenocarcinoma were 4%, 88% and 51% respectively.These indicate that genetic changes of p53 gene play an important role in the transformation from benign adeuoma to adenocarcinoma. p53 immunohistochcmistry can be used as a surrogate marker for p53 gene mutation for early discovery of colorectal adenocarcinomas.展开更多
Objective: To investigated p53 gene mutation in plasma of gastric cancer patients. Methods: DNA extracted from plasma and matched tumor and tumor-adjacent non-cancerous tissues of 96 gastric cancer patients, and DNA f...Objective: To investigated p53 gene mutation in plasma of gastric cancer patients. Methods: DNA extracted from plasma and matched tumor and tumor-adjacent non-cancerous tissues of 96 gastric cancer patients, and DNA from 20 healthy volunteers were studied. Exon 5, 6, 7, and 8 of p53 were amplified by Polymerase Chain Reaction (PCR). The mutation status was analyzed by denaturing high-performance liquid chromatography (DHPLC), followed by direct sequencing of cases with aberrant chromatographic patterns. Results: Heterozygous mutations of p53 gene were detected in 19.9% (19/96) of primary tumor tissues and 5.2% (5/96) of corresponding plasma. All p53 gene mutations detected in plasma DNA consisted with mutations in the matched primary tumor samples. Neither the tumor-adjacent gastric mucosa tissues nor control plasma from healthy volunteers showed p53 gene mutation. No correlation was found between p53 mutation status and clinicopathological features of gastric cancer patients. Conclusion: p53 gene mutation in plasma can be detected in tissues and plasma of gastric cancer patients, which could be applied in screening and surveillance of this disease.展开更多
The accumulation of mutant p53 protein in cancer cells was observed by immunohistochemistry analysis. DNA was extracted from paraffin-embedded tissue. Exons 5, 7 and 8 were amplified and studied by PCR-SSCP and sequen...The accumulation of mutant p53 protein in cancer cells was observed by immunohistochemistry analysis. DNA was extracted from paraffin-embedded tissue. Exons 5, 7 and 8 were amplified and studied by PCR-SSCP and sequencing analysis. Ten cases of asbestos associated cancer tissue were studied, of which five cases had adenocarcinoma, and the other five had mesothelioma, squamous carcinoma, small cell lung cancerl adenosquamous carcinoma and malignant lymphoma respectively. Employing monoclonal antibody PAb1801, five cases were found to be mutant p53 protein mpitive. Seven cases were found to have mutations by PCRSSCP. A total of 7 cases (8 mutations) were found to be positive and 4 cases were found to be opitive by both of these analyses. Of the 8 mutations found by SSCP analysis, 4(50%, 4/8)were clustered in exon 8. A high mutation frequency was noticed in adenocarcinoma (80%,4/5). ffequencing analysis on two specimens revealed two hotspot mutations. In codon 234,TAC for tyrooin was mutated to AAC fOr aspar8gine by a T to A transversion of the first letter. In codon 273, CGT for arginine was mutated to AGT for serine by a C to A transversion of the first letter. ln conclusion, the mutation of p53 gene is common in asbestos associated cancers. However, the mutational spectrum of asbestos associated cancers might be different from that of non-asbestos associated cancers.展开更多
DNA from 36 patients with chronic myelogenous leukemia (CML) at various clinical stages and 6 cases of acute leukemia was investigated for alterations of the p53 gene by Southern blot analysis.Rearrangements of the p5...DNA from 36 patients with chronic myelogenous leukemia (CML) at various clinical stages and 6 cases of acute leukemia was investigated for alterations of the p53 gene by Southern blot analysis.Rearrangements of the p53 gene were seen in 3 of 12 (25.00%) cases of blast crisis and accelerated phase (AP) of CML and in only one of 18 chronic phrase (CP),just as has been reported previously. Meanwhile,by restriction fragment length polymorphism (RFLP) analysis the Bgl II site polymorphism in the p53 gene was also found. The frequency in Chinese people detected here was 0.392,which was strikingly higher than that in some other countries(P<0. 001).These results suggested that the alterations of the p53 gene, for example,p53 rearrangements,were probably responsible for the progression of BC in some CML patients, and that the frequency of Bgl II polymorphism in the p53 gene might be related to the population distribution.展开更多
The special primers Of p53 exon 7 as wed as HPV16 E6 and E7 ORFs (Opening Rending Frame) were used with PCR, PCR-SSCP technique, and 35 specimens of cervical carcinoma were examined. The results were as follows: ① H...The special primers Of p53 exon 7 as wed as HPV16 E6 and E7 ORFs (Opening Rending Frame) were used with PCR, PCR-SSCP technique, and 35 specimens of cervical carcinoma were examined. The results were as follows: ① HPV16 E6, E7 DNA was found in 25/35 specimens (71. 4%),which proved again HPV16 Infection an important event in cervical carcinogenesis. However only 11/35 (31.42% ) bad E6 and E7 ORFs simultaneously, 3/35 (8. 57%) and 11/35 (31. 42% ) had only E6 or E7 respectively. ② No mutation and LOH (Loss of Heterozygote) of p53 exon 7 were found in allof 35 specimens. Additionally in the present study, we developed a non-isotopic PCR-SSCP method.展开更多
Summary: To understand P53 gene change of non Hodgkin's lymphoma (NHL) and human malignant lymphoma cell lines, the exons 5 7 of 29 patients with NHL and 9 kinds of human malignant lymphoma cell lines were st...Summary: To understand P53 gene change of non Hodgkin's lymphoma (NHL) and human malignant lymphoma cell lines, the exons 5 7 of 29 patients with NHL and 9 kinds of human malignant lymphoma cell lines were studied by silver staining PCR SSCP technique. Three cases of P53 gene point mutation was found in 29 cases of NHL. Mutation developed in exon 5 in 2 cases, and in exon 6 in 1 case. They were all diffuse lymphoma. In mutation cases, B cell lymphoma accounted for 2 cases and the other one was T cell lymphoma. There was no P53 gene mutation in low grade follicular lymphoma. Seven strains out of 9 kinds of lymphoma cell lines had P53 gene point mutation. One strain had the mutation in exon 5; 5 strains in exon 6 and 1 strain in exons 5, 6, 7. There was a high mutation rate in lymphoma cell lines and low mutation rate in NHL patients. P53 gene plays an important role in lymphoma cell line establishment, cell regeneration and disease evolution.展开更多
基金supported by the Chinese High-Tech Program(863)Chinese Key Basic Research Project(973)the National Natural Science Foundation of China.Gratitude was extended to Prof.Zhu CHEN for his suggestion and direction of this work.
文摘To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular
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
基金This work was supported by the National Natural Foundation of China (No. 39670234 )
文摘Objective: To evaluate the effect of adenovirus-mediated p53 gene (Adp53) on apoptosis andradiosensitivity of human gastric carcinoma cell lines.Methods: Recombinant adenovirus expressing wild-type p53 gene was transferred into four human gastric carcinoma cell lines with different p53 genetic status. p53 proteinexpression was detected by immunohistochemistry assayand western blot assay. Cell survival was assessed using a clonogenic assay. TUNEL assay was used in determination of apoptosis. Four human gastric carcinoma cells infectedwith Adp53 were irradiated with 4Gy and cell cycle distribution and Sub-G1 peak were assayed by flowcytometry. Results: G2/M arrest, apoptosis and inhibition of tumor cell proliferation were induced by infection atAdp53 at 100 MOI which caused high transfer rate ofwild-type p53 and strong expression of p53 protein in four human gastric carcinoma cells. The radio-enhancement ratio of Adp53 at 4Gy were 3.0 for W cell, 3.6 for M cell, 2.2 for neo cell and 2.5 for 823 cell in vitro. Conclusion: Thisstudy demonstrated that Adp53 transfer increased cellularapoptosis and radiosensitivity of human gastric carcinoma cell lines in vitro independently on cellular intrinsic p53status thus supporting the combination of p53 gene therapy with radiotherapy in clinical trials.
文摘Objective: To study the effect of Shugan Shuru Granule (疏肝舒乳颗粒,SSG) on the p53 gene expression in patients with hyperplastic disease of breast (HDB) to indirectly explore the mechanism of SSG’s effect on HDB on the molecular pathological level. Methods: Sixty-six patients with HDB were allocated in the treated group and the control group,with the former treated with SSG and the latter not. All patients underwent breast operation and their diseased mammary tissues were cut out, sectioned, and observed under microscopy with HE staining and immunohistochemical staining, with ABC method adopted to estimate the degree of hyperplasia and p53 gene expression. The severity of HDB was classified into normal, mild, moderate and severe grades (marked as 0 to Ⅲ), according to the degree of hyperplasia in the mammary gland. Results: Hyperplasia in the control group mostly belonged to grade Ⅰ-Ⅲ before treatment, showing overgrowth of gland and proliferation of glandular epithelial cells, which were high columnar shaped, more stratified, with papillary or substantive dysplasia. While in the treated group, most belonged to grade 0-Ⅰ after SSG treatment, with proliferated gland and dysplasia recovered to normal or disappeared. The positive rate of p53 gene expression in the treated group was 9.09%, and in the control group 39.39%, comparison between the two groups showing significant difference (P<0.01), the intensity in the former was significantly weaker than that in the latter.Conclusion: SSG could not only inhibit the proliferation of mammary duct epithelia and lobuli, but also inhibit the over-expression of P53. Therefore, it could be regarded as an effective remedy for treatment of HDB and prevention of mammary cancer genesis.
基金Key Discipline Key Projects in Guangdong Province (9808)
文摘BACKGROUND: Current studies related to the effects of proanthocyanidins on Alzheimer's disease have focused primarily on the signal transduction pathway of cellular apoptosis. However, the influence of p53 gene expression on cell cycle regulation, with regard to the protective mechanisms of proanthocyanidins, has not been reported. OBJECTIVE: To observe the effect of proanthocyanidins on cell cycle distribution, cellular apoptosis and p53 gene expression in β-amyloid peptide (25-35) (Aβ25-35)-induced PC12 cells cultured in serum-free media, and to investigate the molecular neuroprotective mechanisms of proanthocyanidins with regard to cell cycle regulation. DESIGN, TIME AND SETTING: A parallel, controlled, at the Institute of Biochemistry and Molecular Biology cellular, and molecular study was performed Guangdong Medical College from July 2006 to July 2008. MATERIALS: Proanthocyanidins were provided by Nanjing Xuezi Medical and Chemical Research Center, China; Aβ25-35 was provided by Sigma, USA; PC12 cells were provided by the Institute of Basic Medical Science, Academy of Military Medical Sciences; and rabbit anti-p53 polyclonal antibody was provided by Santa Cruz Biotechnology, USA. METHODS: PC12 cells were cultured in serum-free media for 24 hours. Cells from the model group were treated with 25 μmol/L Aβ25-35 for 24 hours. Cells in the drug protection group were pre-treated with 30 mg/L proanthocyanidins for 1 hour and then treated with 25 μmol/LAβ2^-35 for 24 hours. The control group was not treated. MAIN OUTCOME MEASURES: Flow cytometry was used to detect cell cycle distribution and rate of apoptosis; reverse-transcriptase polymerase chain reaction was used to detect p53 mRNA expression; and Western blot was used to detect p53 protein expression. RESULTS: After treating with 25 μmol/LAβ25-35 for 24 hours, the rate of apoptosis and the percentage of cells in S phase were significantly increased (P 〈 0.01 ), and p53 mRNA and protein expressions were decreased. Pretreatment with proanthocyanidins for 1 hour blocked the increase in apoptosis and the percentage of cells in S phase in Aβ25-35-induced PC12 cells (P 〈 0.01 ) and increased p53 mRNA and protein expressions. CONCLUSION: Proanthocyanidins blocked apoptosis and S-phase arrest in Aβ25-35-induced PC12 cells cultured in serum-free media. The protective mechanism could be related to increased p53 mRNA and protein expressions.
文摘gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and to approach the mechanism of infiltration and metastasis of gastric carcinoma. The results showed that nuclear expression of p53 protein was significantly related to tumor size, depth of invasion, lymph node and liver metastases; but not related to histological differentiation. It is suggested that the accumulation of p53 protein was increased with the progression of gastric carcinoma, and therefore the cancer clone with p53 gene mutation may play an important role in the development of tumor invasion and metastasis.
文摘By southern hybridization with 1. 8 kb cDNA probe,a high frequency (40. 5 % ) of structural abnor- mality of p53 gene was observed in primary nasopharyngeal carcinoma (NPC) biopsies. The regions of ex- ons 1 to 4 of the gene were examined by polymerase chain reaction-single strand con formation polymor- phism,no point mutation was found. Because very low rate of point mutation had been reported in exons 5 to 8, we considered that structural abnormality in the region of e-cons 1 to 8 of the gene might be uncom- mon in NPC. The spectrophotometer scanning analysis of autoradiograms and rehybridization investigation of nitrocellulose filter with exon 11 probe indicated that most of structure aberrations we observed might be rearrangement occurring in exon 11.
文摘BACKGROUND: It is of significance for single nucleotide polymorphisms (SNPs), a difference of rank, which exists widely in biology, genetics and other fields. OBJECTIVE: To detect polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province. DESIGN: Simple random sampling. SETTING: Department of Surgery of the 118 Hospital of Chinese PLA.PARTICIPANTS: A total of 80 healthy people in Han nationality were selected from hospitals in Zhejiang province from August 2005 to January 2006. There were 43 males and 37 females aged from 3 to 78 years with the mean age of 39.5 years, and all subjects were consent. DNA which was used in genetic analysis was selected from peripheral venous blood of all subjects and maintained at -20℃.METHODS: Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene were detected with directly DNA sequencing technique. MAIN OUTCOME MEASURES : Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province. RESULTS: A total of 80 samples were involved in the final analysis. SNPs sites were found at the 119^th base of exon-4 of p53 gene (the 72^nd codon of p53 gene), the 670^th base of upper start codon in promotor of Fas gene (Fas-670), and the 995^th base of intron-7 of Fas gene, especially SNPs in the 995^th base of intron-7 pf Fas gene, i.e. C→A transversion, was a new site.CONCLUSION : One unknown SNPs site is discovered in intron-7 of Fas gene of people in Han nationality in Zhejiang province. This study also proves that the 72^nd codon exists in p53 gene and the -670 polymorphism site exists in promotor of Fas gene.
文摘转录调节蛋白TP 53(Tumor protein 53)调控多种重要生物学过程,包括细胞周期、DNA损伤、修复和细胞凋亡等.在各种应激条件下tp53会被激活并发挥与应激相关的调控作用,但tp53在鱼类低温应激下的作用尚不明了.本文首先检测在低温应激条件下斑马鱼(Danio rerio)中tp53的表达变化,然后利用tp53^(-/-)斑马鱼敲除模型研究了敲除tp53对斑马鱼低温耐受能力和运动的影响.RT-qPCR结果显示:在8℃低温条件下野生型斑马鱼全鱼和鳃组织中tp53的mRNA水平显著升高.低温耐受实验显示:8℃低温下tp53^(-/-)斑马鱼的耐受能力增强,半数致死时间(lethal time to 50%mortality, LT50)显著高于WT(Wild type)对照组(P<0.000 1).运动行为学实验发现:与28℃相比,18℃低温下WT和tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著降低(P<0.000 1);同时发现在28℃和18℃条件下,tp53^(-/-)斑马鱼的移动距离、平均速度和活跃度均显著高于WT组.研究结果说明tp53参与斑马鱼的低温响应过程,敲除tp53后斑马鱼的耐寒能力与运动能力增强.本文为鱼类的低温耐受机制和运动行为学研究提供了新思路.
文摘Objective: In most laryngeal cancers, the function of p53 gene is down regulated. To explore the potential use of p53 in gene therapy of laryngeal cancer, by introducing wild-type p53 into laryngeal cancer cell line via a recombinant adenoviral vector, Ad5CMV-p53 and analyzing its effects on cell and tumor growth. Methods: A human laryngeal cancer, cell line Hep-2 was used. Recombinant cytomegalovirus-promoted adenoviruses containing human wild-type p53 cDNA was transiently introduced into Hep-2 line. The growth suppression of the Hep-2 cells and established s.c. squamous, carcinoma model was examined. The p53 protein expression was detected using immunohistochemical analysis. Results: The transduction efficiencies of Hep-2 cell line were 100% at a multiplicity of 100 or greater. The p53 protein expression peaked on day 2 after infection and lasted far 5 days. In vitro growth assays revealed cell death following Ad5CMV-p53 infected. In vivo studies, Ad5CMV-p53 inhibited the tumorigenicity of Hep-2 cell, and in nude mice with established s.c. squamous, carcinoma, nodules showed that tumor volumes were significantly reduced in mice that received peritumoral infiltration of Ad5CMV-p53. Conclusion: Adenovirus-mediated antitumor therapy carrying the p53 gene is an efficient method to inhibit laryngeal cancer growth. Transfection of laryngeal cancer cells with the wild-type p53 gene via Ad5CMV-p53 is a potential novel approach to the therapy of laryngeal cancer.
基金the Research Foundation of the Ministry of Public Health of PR China !(No. 94-1-316).
文摘Objective: To determine the feasibility of detecting p53 gene mutations for early diagnosis of lung cancer using the samples from bronchoscopic examination. Methods: Point mutations of the exon 5-8 of p53 gene were detected in 85 bronchoscopic samples of 35 patients suspected to be lung cancer using silver staining PCR-SSCP. Results: p53 gene mutations were founded in 10 of 35 patients(28.6%). The incidence of p53 gene mutations (14.9%) was obviously higher than the cytological positive incidence(2.9%) in samples of sputum, bronchoalveolar lavage and brush, especially for the sputum(27.7%). In the bronchoscopic biopsy specimens, the incidence of p53 gene mutations (12.5%) was lower than that of pathologic positive result (50.0%). However, in view of all the bronchoscopic samples, there was no statistically difference between cytopathologic positive results (11.8%) and the incidence of p53 gene mutations (14.1%). Although the p53 mutations were most common in the samples from the patients bronchoscopically manifested as neoplasm compared with other manifestations, there was no statistical difference. It is valuable to notice that 3 patients with p53 gene mutation merely presented as bronchial inflammation in bronchoscope. Conclusion: Results indicated that the value of detecting p53 gene mutation for the diagnosis of lung cancer using the bronchoscopic samples was more superior to cytological examination and detection of p53 gene mutations in post-bronchoscopic sputum was easy and effective, may be used as a valuable method for early diagnosis of lung cancer.
文摘Summary: To evaluate the effect of wild type p53 gene on the growth and radiotherapeutic sensitivity of human glioma cells, plasmid PC53 SN3 carrying wild type p53 gene was transfected into U251 cells, p53 gene expression in transfected cells was detected by RT PCR, and the cell growth inhibition and apoptosis in the absence or presence of irradiation were assessed by MTT and flow cytometry. The transfection of p53 gene into U251 cells was confirmed by RT PCR. MTT showed that p53 gene alone induced strong inhibitory effect on the growth of U251 cells (inhibition rate (IR): (79.60±5.69)%), The killing effect of irradiation alone on U251 cells was not strong (IR: (17. 06±4.35)%, (17.39±1.67)%, (18.73±4.68)%) and increased with the irradiation doses (3, 6, 9 Gy). When combined treatment of wild-type p53 gene transfection and irradiation was used, the effect was significantly increased (IR:(80.60±5.35)%, (90.30+1.67) %, (91.30±2.01) %). Theapoptosis rate of U251 cells induced by p53 gene transfectionwas 17.38 %. The rate induced by irradiation increased (4. 61%, 4. 84%, 5. 40 %) with the irradiation doses (3, 6, 9 Gy). Theapoptosis rate was also significantly increased (17.80%, 20.03%, 22.34%) after combined treatment of p53 and irradiation with different doses (3, 6, 9 Gy). It is concluded that wildtype p53 gene and irradiation could result in synergistic inhibitory effect on the growth of human glioma cells.
文摘Using a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) approach we analyzed 18 human colorectal adenocarcinomas for mutations in exons 5,6,7,8 of p53 gene. At the same time,p53 gene product expression was studied immunohistochemically in these 18 case in frozen sections. The expression of p53 protein was also immunohistochemically studied in formalin-fixed paraffin embeded spccimens of 76 colorectal adenocarcinomas and 112colorectal polyps. Eigbt out of 18 cases (44%) showed a variant band indicative of a mutation in exons 5-6 of p53gene 7 out of 8 cascs (88%) with p53 gene mutations were positivelystanined for P53. There was no significant correlation between p53. expression and clinicopathological manifestations and prognosis. but the strongest staining was cncountered in those cases with well differentiated and early stage adenocarcinomas,while weaker staining was encountered in Poorly differentiated and mucoid adenotarcinomas. p53expression was not observed in proliferative polyps and adenomas with low grade dysplasia. The frequency of p53expression reached 88% (p<0.001) when adenoma showed malignant change. Aiuong three types of adenomas, p53 expression was most frequent in villous type (P<0.05). The frequencies of p53 expression in adenoma, adenoma with malignant change and adenocarcinoma were 4%, 88% and 51% respectively.These indicate that genetic changes of p53 gene play an important role in the transformation from benign adeuoma to adenocarcinoma. p53 immunohistochcmistry can be used as a surrogate marker for p53 gene mutation for early discovery of colorectal adenocarcinomas.
文摘Objective: To investigated p53 gene mutation in plasma of gastric cancer patients. Methods: DNA extracted from plasma and matched tumor and tumor-adjacent non-cancerous tissues of 96 gastric cancer patients, and DNA from 20 healthy volunteers were studied. Exon 5, 6, 7, and 8 of p53 were amplified by Polymerase Chain Reaction (PCR). The mutation status was analyzed by denaturing high-performance liquid chromatography (DHPLC), followed by direct sequencing of cases with aberrant chromatographic patterns. Results: Heterozygous mutations of p53 gene were detected in 19.9% (19/96) of primary tumor tissues and 5.2% (5/96) of corresponding plasma. All p53 gene mutations detected in plasma DNA consisted with mutations in the matched primary tumor samples. Neither the tumor-adjacent gastric mucosa tissues nor control plasma from healthy volunteers showed p53 gene mutation. No correlation was found between p53 mutation status and clinicopathological features of gastric cancer patients. Conclusion: p53 gene mutation in plasma can be detected in tissues and plasma of gastric cancer patients, which could be applied in screening and surveillance of this disease.
文摘The accumulation of mutant p53 protein in cancer cells was observed by immunohistochemistry analysis. DNA was extracted from paraffin-embedded tissue. Exons 5, 7 and 8 were amplified and studied by PCR-SSCP and sequencing analysis. Ten cases of asbestos associated cancer tissue were studied, of which five cases had adenocarcinoma, and the other five had mesothelioma, squamous carcinoma, small cell lung cancerl adenosquamous carcinoma and malignant lymphoma respectively. Employing monoclonal antibody PAb1801, five cases were found to be mutant p53 protein mpitive. Seven cases were found to have mutations by PCRSSCP. A total of 7 cases (8 mutations) were found to be positive and 4 cases were found to be opitive by both of these analyses. Of the 8 mutations found by SSCP analysis, 4(50%, 4/8)were clustered in exon 8. A high mutation frequency was noticed in adenocarcinoma (80%,4/5). ffequencing analysis on two specimens revealed two hotspot mutations. In codon 234,TAC for tyrooin was mutated to AAC fOr aspar8gine by a T to A transversion of the first letter. In codon 273, CGT for arginine was mutated to AGT for serine by a C to A transversion of the first letter. ln conclusion, the mutation of p53 gene is common in asbestos associated cancers. However, the mutational spectrum of asbestos associated cancers might be different from that of non-asbestos associated cancers.
文摘DNA from 36 patients with chronic myelogenous leukemia (CML) at various clinical stages and 6 cases of acute leukemia was investigated for alterations of the p53 gene by Southern blot analysis.Rearrangements of the p53 gene were seen in 3 of 12 (25.00%) cases of blast crisis and accelerated phase (AP) of CML and in only one of 18 chronic phrase (CP),just as has been reported previously. Meanwhile,by restriction fragment length polymorphism (RFLP) analysis the Bgl II site polymorphism in the p53 gene was also found. The frequency in Chinese people detected here was 0.392,which was strikingly higher than that in some other countries(P<0. 001).These results suggested that the alterations of the p53 gene, for example,p53 rearrangements,were probably responsible for the progression of BC in some CML patients, and that the frequency of Bgl II polymorphism in the p53 gene might be related to the population distribution.
文摘The special primers Of p53 exon 7 as wed as HPV16 E6 and E7 ORFs (Opening Rending Frame) were used with PCR, PCR-SSCP technique, and 35 specimens of cervical carcinoma were examined. The results were as follows: ① HPV16 E6, E7 DNA was found in 25/35 specimens (71. 4%),which proved again HPV16 Infection an important event in cervical carcinogenesis. However only 11/35 (31.42% ) bad E6 and E7 ORFs simultaneously, 3/35 (8. 57%) and 11/35 (31. 42% ) had only E6 or E7 respectively. ② No mutation and LOH (Loss of Heterozygote) of p53 exon 7 were found in allof 35 specimens. Additionally in the present study, we developed a non-isotopic PCR-SSCP method.
文摘Summary: To understand P53 gene change of non Hodgkin's lymphoma (NHL) and human malignant lymphoma cell lines, the exons 5 7 of 29 patients with NHL and 9 kinds of human malignant lymphoma cell lines were studied by silver staining PCR SSCP technique. Three cases of P53 gene point mutation was found in 29 cases of NHL. Mutation developed in exon 5 in 2 cases, and in exon 6 in 1 case. They were all diffuse lymphoma. In mutation cases, B cell lymphoma accounted for 2 cases and the other one was T cell lymphoma. There was no P53 gene mutation in low grade follicular lymphoma. Seven strains out of 9 kinds of lymphoma cell lines had P53 gene point mutation. One strain had the mutation in exon 5; 5 strains in exon 6 and 1 strain in exons 5, 6, 7. There was a high mutation rate in lymphoma cell lines and low mutation rate in NHL patients. P53 gene plays an important role in lymphoma cell line establishment, cell regeneration and disease evolution.