OBJECTIVES: Mutation of p53 may play a role in manifestation of rheumatoid arthritis synovium, but several studies on p53 expression in synovial tissues of rheumatoid arthritis showed conflicting results. We investigated the amount and pattern of p53 positive cells in rheumatoid arthritis synovium, in comparison with osteoarthritis synovium, by using immunohistochemistry with two other monoclonal antibodies for p53. METHODS: Synovial tissues from 9 patients with rheumatoid arthritis and 5 patients with osteoarthritis were examined for p53 expression by immunohistochemistry with 2 monoclonal antibodies for p53, DO-1 and DO-7. Histologic features of inflammation were also scored and compared with p53 expression. RESULTS: There was no significant difference between inflammatory scores in both groups. In the synovial tissues of rheumatoid arthritis patients, p53 positive cells were detected in 3 out of 9 samples(33%) and p53 expressions were restricted to inflammatory mononuclear cells, but synovial lining cells, subsynovial fibroblast-like cells and vascular endothelial cells were p53 negative. p53 expressions in osteoarthritis synovial tissues as control were observed in 2 out of 5 samples(40%) and the amount and pattern of p53 positive cells were comparable to those seen in rheumatoid arthritis synovial tissues. There was no demonstrable correlation between the synovial tissues of both groups with respect to inflammation scores and expression of p53 protein. CONCLUSION: Our findings suggest that altered p53 expression may not play a significant role in the manifestation of rheumatoid arthritis synovium. However these data need to be strengthened by increasing the number of samples and molecular biology approaches.
Arthritis, Rheumatoid/metabolism* ; Arthritis, Rheumatoid/genetics ; Comparative Study ; Gene Expression ; Genes, p53 ; Human ; Immunohistochemistry ; Osteoarthritis/metabolism ; Osteoarthritis/genetics ; Protein p53/metabolism* ; Protein p53/genetics ; Synovial Membrane/metabolism

OBJECTIVETo observe the effect of recombinant adenovirus-mediated wild-type p53 gene on the number and proteins of centrosome in K562 cells. To explore the possibility of application of wild-type p53 gene therapy in the treatment of chronic myeloid leukemia.

METHODSThe recombinant adenoviruses carrying wild-type p53 gene (Ad5 wtp53), mutant p53 gene (Ad5 mtp53) or the green fluorescent protein (GFP) gene was repeatedly amplified and co-infected into K562 cells with cation polybrene. The optimal infection titer and infection time of the recombinant adenoviruses were determined by MTT assay, p53 mRNA and protein expression were determined by RT-PCR and Western blot respectively. The centrosomal structural protein gamma-tubulin and the spindle protein alpha-tubulin were marked simultaneously by indirect immunofluorescence staining, and the expression of the centrosomal gamma-tubulin protein, the mitosis and the number of centrosome were observed under the laser confocal microscopy.

RESULTSInfection efficiency with recombinant adenoviruses was facilitated by polybrene in K562 cells, and 4 microg/ml polybrene was chosen. The optimal adenovirus infection titer was 20,000 MOI and the optimal infection time was 72 hours. p53 mRNA and P53 protein can be expressed in K562 cells by Ad5wtp53 and Ad5mtp53. Both the expression of the centrosomal gamma-tubulin protein and the number of centrosomes were decreased after Ad5wtp53 infection.

CONCLUSIONThere is sustained expression of P53 protein in K562 cells after its infection by Ad5wtp53. Wild-type P53 protein can lead to the down-regulation of the number of centrosomes and the expression of centrosomal gamma-tubulin protein in K562 cells.

Adenoviridae ; genetics ; Centrosome ; metabolism ; Genes, p53 ; genetics ; Genetic Vectors ; Humans ; K562 Cells ; Transfection ; Tubulin ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

p53 is considered as the "master regulator" in DNA damage-induced cell apoptosis. However, p53 is the most frequently mutated gene in human cancers (more than 50 %). Thus the research of p53-independent pathway in cell apoptosis may ultimately provide new therapeutic opportunities for many cancers. It has been shown that Caspase 2, p73, p63, and NF-kappa B-related signaling pathways are involved in DNA damage-induced, p53-independent cell apoptosis. This article reviews the recent research progress in these signaling pathways.
Apoptosis ; genetics ; DNA Damage ; Humans ; Signal Transduction ; Tumor Suppressor Protein p53 ; genetics ; metabolism

OBJECTIVETo evaluate the prognostic significance of p53 mutation and P53 protein expression abnormality among esophageal cancer.

METHODSThe results of 27 random controlled trials from 1990 to 2003 were analyzed by meta-analysis method. The overall positive rate of p53 was 52.9% among the cumulative 2174 cases. Relative hazard (RH) was applied to evaluate the risk of disease and all data were analyzed by Dersimonian-Laird method.

RESULTSThe analysis for homogeneity (q statistics test) showed that all eligible studies were with heterogeneity (q = 59.88, P < 0.005). The combined RH was 2.07 and 95% confidence interval was 1.58-2.70.

CONCLUSIONFindings showed that p53 was a poor prognosis biomarker for esophageal cancer gene diagnosis but might benefit to the strategy of treatment.

Carcinoma, Squamous Cell ; genetics ; metabolism ; Esophageal Neoplasms ; genetics ; metabolism ; Female ; Genes, p53 ; genetics ; Humans ; Male ; Mutation ; Prognosis ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVETo study the over-expression of mutant p53 protein in non-mucinous adenocarcinoma in-situ (NMAIS) and invasive adenocarcinoma, NOS of lung.

METHODSImmunohistochemical study for p53 protein was performed on 17 cases of NMAIS and 70 cases of invasive adenocarcinoma, NOS of lung. The difference in p53 over-expression between the two tumor subtypes was analyzed.

RESULTSThe over-expression of mutant p53 protein was observed in 0 case (0%) of NMAIS and 37 cases (52.9%) of invasive adenocarcinoma, NOS of lung. The difference was of statistical significance (P = 0.000).

CONCLUSIONMutant p53 protein over-expression may play a role in the progression of NMAIS to invasive adenocarcinoma, NOS.

Adenocarcinoma ; metabolism ; Adenocarcinoma in Situ ; metabolism ; Humans ; Immunohistochemistry ; Mutant Proteins ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism

BACKGROUND: Cyclin-dependent kinase inhibitors (CDKI), including p21, p27 and p57 of the KIP family, are negative regulators of cell cycle progression and potentially act as tumor suppressors. The expression of p21 is induced by tumor suppressor gene p53. Mutations of p53 are common and found in various human cancers. Thus, the function of p21 as a tumor suppressor may be not retained after p53 mutation in human cancers. The aim of our study was to evaluate the tumor suppressive activity of p21 and p53 in human gastric cancer. METHODS: One hundred and two patients who underwent surgery for gastric cancer at Chonnam National University Hospital were selected retrospectively for this study. The primary selection criteria were the availability of formalin-fixed and paraffin-embedded blocks and sufficient clinical follow-up for tumor-specific survival analysis. In this study, we examined the expression of p21 and p53 in human gastric cancer tissue by immunohisto-chemistry and the correlation between their expression and clinicopathological variables. RESULTS: p21 and p53 immunoreactivities were localized in the nuclei of carcinoma cells. Positive nuclear expression of p21 and p53 was demonstrated in 63.7 and 33.3% of cancer tissues, respectively. No apparent correlation was noted between p21 and p53 expression. Negative expression of p21 correlated with advanced stage and lymph node metastasis (p=0.028 and 0.017, respectively). Moreover, negative expression of p21 correlated with poor survival (p=0.037). Positive expression of p53 correlated with depth of tumor invasion (p=0.029). However, no significant correlation could be observed between the status of p53 expression and survival. Combined analysis of p21 and p53 status showed that p21 negative and p53 positive tumors had a poorer survival than other group tumors (p=0.026). CONCLUSION: These results suggest that the status of p21 and p53 expression may help in predicting the aggressive behavior of gastric cancer. However, further studies are warranted to clarify the impact of p53 on the function of p21 as a tumor suppressor.
Adult ; Aged ; Carcinoma/genetics/*metabolism ; Female ; Gene Expression ; Genes, p53 ; Human ; Male ; Middle Aged ; Oncogene Protein p21 (ras) /genetics/*metabolism ; Prognosis ; Protein p53/genetics/*metabolism ; Retrospective Studies ; Stomach Neoplasms/genetics/*metabolism ; Survival Analysis ; Tumor Markers, Biological/genetics/*metabolism

Animals ; Genes, p53 ; Genetic Therapy ; Humans ; Neoplasms ; genetics ; metabolism ; therapy ; Proto-Oncogene Proteins c-mdm2 ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism

To investigate the potential implication of the subtype of intestinal metaplasia in the progression to the gastric carcinoma, we analyzed the mutations of the p53 gene and microsatellite instability (MSI) both in the complete type (type I) and in the sulphomucin-secreting incomplete type (type III) intestinal metaplasia located adjacent to the gastric carcinoma. p53 mutations were observed in 13.3% of type I, in 6.6% of type III intestinal metaplasia, and in 40% of gastric carcinoma. The difference between p53 mutations observed in type I and type III intestinal metaplasia was not statistically significant. No identical mutation of the p53 gene was found in the intestinal metaplasia and carcinoma specimens from the patients. There was no case of intestinal metaplasia showing MSI. In gastric carcinomas, MSI was observed in six cases (40%). The cases harboring BAT-26 instability did not have the mutation of the p53 gene. These data suggest that intestinal metaplasia adjacent to gastric carcinoma, irrespective of its subtype, do not have the genetic alterations as showing in their carcinoma tissues.
Carcinoma/genetics/pathology ; Exons ; *Genes, p53 ; Humans ; Metaplasia/genetics/pathology ; *Microsatellite Repeats ; *Mutation ; Precancerous Conditions ; Stomach/*pathology ; Stomach Neoplasms/genetics/pathology ; Tumor Suppressor Protein p53/genetics/metabolism

Acetylation ; Animals ; Humans ; Phosphorylation ; Tumor Suppressor Protein p53 ; chemistry ; genetics ; metabolism ; physiology

OBJECTIVETo investigate the role of p53 on ran transcription in myeloma cells.

METHODSUsing real-time fluorescence quantitative PCR, the ran transcription level was measured in 8 human myeloma cell lines such as OPM-2, RPMI-8226, U-266, KAS6/1, ANML-6, H-929, MM1.S and MOLP-8. The ran transcription level and P53 expression were detected by Q-PCR in MM1.S treated with Nutlin-3a for 24, 48 and 72 hours, respectively. The Western blot was used to detect the expression levels of ran and P53 proteins, and ran expression level after transfection of MM1.S cells using different concentration of plasmids which express the P53 luciferase reporter.

RESULTSH-929 and MM1.S cells showed the highest ran transcription level among the above-mentioned 8 cell lines (P<0.05). After treatment with Nutlin-3a, ran transcription level in MM1.S cells decreased (P<0.05), (r=-1.00, P=0.04) and P53 expression increased (r=1.00, P=0.06) in time-dependence manner. The detection by p53 luciferase reporter showed that the ran transcription decreased and the plasmid increased to 25 ng (P<0.05).

CONCLUSIONThis study demonstrated that ran is a target gene regulated by P53 in myeloma cells for the first time.

Cell Line, Tumor ; Humans ; Imidazoles ; pharmacology ; Multiple Myeloma ; genetics ; metabolism ; Piperazines ; pharmacology ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; ran GTP-Binding Protein ; genetics ; metabolism