OBJECTIVETo study relation of the expression of hTERT mRNA and cyclin A, p53 protein, proliferation cell nuclear antigen (PCNA) in ameloblastoma (AB) and to investigate clinical biological characteristics of AB.

METHODSThe hTERT mRNA was detected by in situ hybridization, cyclin A, p53 protein and PCNA by SP method. Normal oral mucosa and odontogenic keratocyst (OKC) are comparition.

RESULTSThe positive ratio of hTERT mRNA was 1/7 cases in normal oral mucosa. The expression of cyclin A, p53 and PCNA in normal oral mucosa were similar, and the positive cells distributed in stratum basale. In OKC, the positive cells distributed in stratum basale and super-strrtum basale. And the positive ratio of hTERT, cyclin A, p53, PCNA in OKC was 14/16 cases, 4/32 cases, 11/25 cases, 5/9 cases, respectively. In AB, the positive ratio of hTERT mRNA, cyclin A, p53 protein and PCNA was 94.4% (51/54), 66.7% (40/60), 85.7% (42/49) and 78.1% (25/32), respectively. A strong correlation was found between hTERT mRNA with cyclin A, p53 protein and PCNA (r(s) = 0.914, 0.848, 0.804, P < 0.05).

CONCLUSIONSThe expression of hTETR mRNA, cyclin A, p53 and PCNA is different in different tissues and lesions, and correlates with cell differentiation and clinical biology behaviour. Telomerase activity is related to cumulation of p53 protein, related to cell proliferation and differentiation, regulated by cyclin A, and higher in S phase.

Ameloblastoma ; metabolism ; pathology ; Cyclin A ; biosynthesis ; Humans ; Jaw Neoplasms ; metabolism ; pathology ; Proliferating Cell Nuclear Antigen ; biosynthesis ; RNA, Messenger ; biosynthesis ; Telomerase ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis

OBJECTIVETo improve the level of clinical diagnosis and differential diagnosis of benign and malignant prostate lesions.

METHODSOne hundred and nine cases of prostate cancer and prostate hyperplasia were evaluated by the expression of high molecular weight cytokeratin (CK34BE12), prostate specific antigen (PSA) and protein P53 gene using the immunohistochemical technique.

RESULTSThe basal-cells in all of the benign lesions were stained with the CK34BE12 and PSA, while it had not immunoreactivity with P53. In contrast, the prostate carcinoma were not stained or partly stained with the CK34BE12 and PSA, but P53 show significant immunoreactivity with the tissue.

CONCLUSIONBased on the routine histological studies with the expression of CK34BE12 and PSA together, they can indicate the existence of basal-cell distinctly and show indirectly whether the basal-cell is integrated. Combining the expression of P53 to determine the existence of cancer gene, it can help to distinguish benign and malignant prostate lesions.

Diagnosis, Differential ; Humans ; Immunohistochemistry ; Keratins ; biosynthesis ; Male ; Prostate-Specific Antigen ; biosynthesis ; Prostatic Neoplasms ; diagnosis ; metabolism ; pathology ; Staining and Labeling ; Tumor Suppressor Protein p53 ; biosynthesis

OBJECTIVETo investigate the relationship between tobacco smoking, drinking and p53 alteration in esophageal carcinoma.

METHODSLiterature on the relationship between p53 alteration in esophageal carcinoma and tobacco smoking, drinking through Meta-analysis were reviewed.

RESULTSIn 14 selected papers related to tobacco smoking, pooled odds ratio (OR) of tobacco smoking with P53 overexpression and p53 alteration were 1.99 (95% CI: 1.30- 3.06) and 1.64 (95% CI: 1.13 - 2.37), respectively (P < 0.05). Pooled OR of tobacco smoking with p53 mutation was 1.11 (95% CI: 0.47 - 2.76) (P > 0.05). In 11 selected papers on alcohol drinking, pooled OR of drinking with P53 overexpression, p53 mutation and p53 alteration were 1.30 (95% CI: 0.83 - 2.04), 1.13 (95% CI: 0.67 - 1.90) and 1.22 (95% CI: 0.87 - 1.72) respectively (P > 0.05).

CONCLUSIONThere were significant relations between tobacco smoking and p53 alteration while there were no significant relations between alcohol drinking and p53 alteration.

Alcohol Drinking ; Esophageal Neoplasms ; etiology ; genetics ; Female ; Genes, p53 ; genetics ; Humans ; Male ; Mutation ; Risk Factors ; Smoking ; adverse effects ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

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 explore the effects of hepatitis B virus X gene and p53 on hepatocellular growth.

METHODSTwo kinds of plasmids containing sense and antisense human wild p53 gene respectively were constructed. SMMU-7721 cells were transfected with HBx, sense-wtp53 antisense-wtp53 separately or cotransfected with either HBx and sense-wtp53 or HBx and antisense-wtp53. Flow cytometry was adopted to measure the apoptosis rates and the effects of HBx on cell cycle progression. The activity of p21(Waf1) promoter-luciferase construct was detected. Growth curves for SMMU-7721 stably transfected with pcDNA3 and pcDNA3HBx were analyzed.

RESULTSAfter doxorubicin administration, HBx was noticed able to initiate apoptosis of the liver cells. The apoptosis rate was 5.32% in the pcDNA3 transfected and 12.66% in the pcDNA3HBx transfected groups respectively. HBx could also abrogate p53-mediated apoptosis. The apoptosis rate in groups transfected with pcDNA3, pcDNA3wtp53 and pcDNA3HBx + pcDNA3wtp53 was 5.32%, 11.72% and 4.67% respectively. In compared with the normal group, the number of cells in transiently HBx-expressed group and HBx-transfected group decreased 4.79% and 10.25% respectively. HBx inhibited the activity of p21(Waf1) promoter-luciferase constructed (P < 0.05) and promoted cell growth. The growth rate of HBx expression cells was faster.

CONCLUSIONUnder DNA damage, HBx reduced expression of p21(Waf1) by repressing the activity of p53 protein, followed by disturbing the regulation of G(0)-G(1) cell cycle checkpoint, and promoted the growth rate of hepatoma cells.

Apoptosis ; Carcinoma, Hepatocellular ; pathology ; virology ; Cell Division ; Cell Line, Tumor ; Genes, p53 ; Hepatitis B Antigens ; biosynthesis ; genetics ; Hepatitis B virus ; genetics ; Humans ; Liver Neoplasms ; pathology ; virology ; Trans-Activators ; biosynthesis ; genetics ; Transfection ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVETo modify the current PCR-based method for rapid and efficient preparation of small interfering RNA (siRNA) expression cassette to improve the efficiency of RNA interference.

METHODSThe U6 promoter sequence was amplified by PCR using the genomic DNA of K562 cells as the template, and cloned into pMD18-T vector which served as the template for further PCR amplification with the primers on the plasmid. The amplified product was directly used as the template for preparing siRNA expression cassette. The siRNA expression cassette targeting p53 gene was amplified, verified by sequencing, and transfected into SH-SY5Y cells. After a 48-hour transfection, the cells were harvested and the total RNA was for RT-PCR for evaluating the effect of RNA interference.

RESULTSThe sequencing result confirmed the correct U6 promoter sequence cloned from K562 cells. After transfection of SH-SY5Y cells for 48 h with siRNA expression cassette, the p53 gene expression was inhibited at the mRNA level in comparison with the control cells as demonstrated by RT-PCR detection.

CONCLUSIONThe siRNA expression cassette prepared using the established method described hereby can be well applicable in RNA interference research.

Gene Silencing ; Gene Targeting ; methods ; Genetic Vectors ; genetics ; Humans ; K562 Cells ; Polymerase Chain Reaction ; RNA, Small Interfering ; biosynthesis ; genetics ; RNA, Small Nuclear ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVETo investigate the toxicological mechanism of microcystin-LR (MCLR) on L-02 cells.

METHODSL-02 cells was treated with MCLR at different concentrations and the subsequent changes such as cell proliferation (MTT assay), morphology, lactate dehydrogenase (LDH) leakage, apoptosis rate and apoptosis-related gene expression were examined.

RESULTSMTT assay showed that MCLR mildly inhibited the cell growth within the initial 24 h of treatment but enhanced the cell viability after that till 60 h in a time- and dose-dependent manner. LDH leakage underwent no marked changes in response to 48-hour MCLR treatment but increased upon prolonged treatment for 60 h, indicating the presence of oxidative damage. After a 48-h treatment with MCLR at 50 microg/ml, obvious apoptosis of L-02 cells occurred as manifested by cell rounding, detachment from the substrate, cell shrinkage and membrane blebbing. The apoptosis rates were rather low (between 22% and 29%) after treatment with MCLR at different concentrations for 36 h, and increased to as much as 80% after a 60-h treatment with 50 microg/ml MCLR. The expressions of p53 and bcl-2 increased in the cells after treatment with high-concentration MCLR, suggesting that MCLR up-regulated the expression levels of the two proteins.

CONCLUSIONMCLR can induce apoptosis and up-regulate p53 and bcl-2 expressions in human normal liver cell line L-02.

Apoptosis ; drug effects ; Cell Line ; Hepatocytes ; cytology ; Humans ; Microcystins ; toxicity ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVE: To investigate the difference of Pax2 and P53 expressions in children with primary nephritic syndrome (PNS) and the effect of Pax2 on glucocorsteroid (GC)-resistance. METHODS: Renal Pax2 and P53 expressions in children with PNS (40 patients) were detected by immunohistochemistry. A semiquantitative score was used to evaluate the injury degree of the glomeruli and the tubulointerstitium, and correlation analysis was done among Pax2, P53 and pathologic score. RESULTS: Pax2 and P53 expressions were not found in the control group. Pax2 expression of renal tubule epithelia exsisted in children with PNS and there was weak or no expression of Pax2 in the podocytes. Pax2 expressions in the proximal tubule and the distal tubule in the GC-resistant group were more intense than those in the GC-intensive group (P <0.01). The more the Pax2 expression in the tubule, the more abnormal structure such as dilation and atrophy. Pax2 expression in the tubule epithelia was positively correlated with pathologic score of tubulointerstitium (P < 0.01). There was no P53 expression in the GC-intensive group, but there exsisted P53 expression in parts of the patients from the GC-resistant group, mainly distributing in the renal tubular epithelia. P53 expression was positively correlated with P53 expression and the pathologic score of tubulointerstitium (P < 0.01). CONCLUSION Over-expression of Pax2 in the renal tubule epithelia may improve P53 expression to a certain degree, which may aggravate the lesion of the renal tubule. It may be one of the mechanisms resulting in GC-resistant in children with PNS.
Adolescent ; Child ; Child, Preschool ; Drug Resistance ; Female ; Glucocorticoids ; therapeutic use ; Humans ; Male ; Nephrotic Syndrome ; drug therapy ; metabolism ; PAX2 Transcription Factor ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVEResearch was done on the possible roles of beta-catenin, p53 and proliferating cell nuclear antigen (PCNA) in the carcinogenesis of colorectal adenoma (CRA).

METHODSbeta-catenin and p53 and PCNA expressions were studied with immunohistochemical stain in 77 specimens of CRA together with mild epithelial dysplasia (CRA-MD), CRA with moderate/severe epithelial dysplasia (CRA-D/SD) and CRA with cancerous changes (CRA-C).

RESULTSThe percentage of abnormal expression of beta-catenin increased during the transition from CRA-MD to CRA-D/SD to CRA-C (P < 0.01). The nuclear expressions of beta-catenin in CRA-D/SD and CRA-C were all significantly higher than that in CRA-MD. Expression of p53 and PCNA were increased from CRA-MD to CRA-D/SD to CRA-C, with the positive rates in these three groups of 10.3%, 43.8%, 75.0% for p53 and 17.2%, 62.5%, 87.5% for PCNA, respectively. 69.7% of cases with positive nuclear beta-catenin expression showed strong PCNA positivity which was much higher than the 36.4% of cases without nuclear beta-catenin expression (P < 0.05). The percentage of strong PCNA expression in the p53 positive cases was significant higher than that in cases with negative p53 expression (72.4% vs 37.5%, P < 0.05). Nuclear beta-catenin and p53 co-expression rates in CRA-C reached 50%.

CONCLUSIONbeta-catenin, p53 and PCNA may play important roles in the carcinogenesis of colorectal adenoma.

Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; biosynthesis ; Colorectal Neoplasms ; diagnosis ; metabolism ; Cytoskeletal Proteins ; biosynthesis ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Prognosis ; Proliferating Cell Nuclear Antigen ; biosynthesis ; Trans-Activators ; biosynthesis ; Tumor Suppressor Protein p53 ; biosynthesis ; beta Catenin

OBJECTIVETo explore hepatitis C virus (HCV) non-structural protein 5A (NS5A)'s influence on inhibition of AFP expression executed by p53 protein and its possible molecular mechanism.

METHODSPlasmid transfection and MEIA were employed to observe p53's inhibitive effect on AFP expression of Huh7 cells and the HCV NS5A's influence on p53 function. Western blot was employed to find out if HCV NS5A affects p53 protein expression and GST pull down assay was applied to examine the interaction between HCV NS5A and p53.

RESULTSThe AFP concentration in the supernatant of the culture of the Huh7 cells transfected with pRc/CMV was (14322+/-2412) ng/ml, and that of the Huh7 cells transfected with pCNS5A was (13843+/-3218) ng/ml; no significant difference existed between these two groups (t = 1.42, P > 0.05). After transfection with pC53-NS3, the AFP level was decreased to (10 241+/-1326) ng/ml, and in comparison to the above two groups it had a statistically significant difference (t values were 2.41 and 2.38, P < 0.05). When co-transfected with pCNS5A and pC53-NS3, the AFP expression (14582+/-1238) ng/ml returned to the level of pRc/CMV transfected, and there was a remarkably significant difference between this and that of the pC53-NS3 transfected cells (t = 3.12, P < 0.01). HCV NS5A had no function on the p53 protein expression with Western blot experiment. In the GST pull down assay, an HCV NS5A protein band was found after GST-p53 was added, but not detected with GST only.

CONCLUSIONWe found that p53 has an inhibitive function on the AFP expression in Huh7 cells and HCV NS5A minimized this p53 function. HCV NS5A did not affect p53 protein expression, but was able to form a complex with p53, by which HCV NS5A inactivated this p53 function.

Carcinoma, Hepatocellular ; metabolism ; virology ; Hepacivirus ; genetics ; Humans ; Liver Neoplasms ; metabolism ; virology ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53 ; genetics ; pharmacology ; Viral Nonstructural Proteins ; genetics ; alpha-Fetoproteins ; biosynthesis ; genetics