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

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

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

OBJECTIVETo explore the effects of bears' bile on tumor cell p53 protein expression with different gene properties.

METHODSThe effects of bears' bile on the expression of p53 protein in 6 cancer cell strains were determined by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Results Western blot analysis showed that the expression of p53 protein in HaCaT, KUMA3, KUMA4 and KUMA6 cell strains with gene mutation were increased, but no change was found in HCT116 and KUMA5 cell strains without gene mutation. There was no quantitative change in p53 mRNA in all cell strains by analysis of p53 mRNA with

CONCLUSIONThe effects of bears' bile on p53 protein expression in cancer cell strains RT-PCR analysis system. could be different based on p53 gene properties,i. e. ,bears' bile only affect p53 protein of mutation type.

Animals ; Bile ; Biological Factors ; pharmacology ; Cell Line, Tumor ; Humans ; RNA, Messenger ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; Ursidae

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 investigate the role of apoptosis stimulating protein 2 of p53 (ASPP2) phosphorylation status in the regulation of ASPP2-p53 apoptotic pathway activity.

METHODSCells were individually transfected with green fluorescent protein (GFP)-encoding vector, constitutively non-phosphorylatable ASPP2 mutant-ASPP2 (Am)-encoding vector, and wild type ASPP2 (Aw)-encoding vector) plasmids, respectively, to make them overexpressing phosphorylated and non-phosphorylated ASPP2 proteins, respectively. Cell apoptosis was induced by oxaliplatin. The apoptosis rate of cells was determined by flow cytometry after staining with FITC-conjugated annexin V and PI. ASPP2 protein level and its phosphorylation status were observed by Western blot. The interaction between ASPP2 and p53 was observed by immunoprecipitation assay.

RESULTSOxaliplatin induced cell apoptosis and caused phosphorylation of ASPP2 at ser92/ser361 in the HCT116 cells. The apoptosis rate of Aw and Am plasmids-transfected cells were (3.8 ± 1.0)% and (3.9 ± 1.2)% respectively, statistically with a non-significant difference (P > 0.05) in comparison with that of the GFP plasmid-transfected cells [(4.0 ± 0.8)%]. After oxaliplatin treatment, the apoptosis rate of Aw plasmid-transfected cells was (46.7 ± 3.9)%, significantly higher than that of the Am and GFP plasmid-transfected cells [(40.1 ± 10.2)% and (37.1 ± 6.9)%, respectively, P < 0.05], however, there was no statistically significant difference (P > 0.05) between Am and GFP plasmid-transfected cells. These results indicate that phosphorylated ASPP2 promoted the oxaliplatin-induced apoptosis of HCT116 cells through a p53-dependent pathway. Phosphorylation status of ASPP2 influenced its binding activity to p53.

CONCLUSIONPhosphorylation status of ASPP2 modulates p53 apoptotic function in oxaliplatin-induced apoptosis of colorectal cancer HCT116 cells.

Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Colorectal Neoplasms ; metabolism ; HCT116 Cells ; Humans ; Organoplatinum Compounds ; Phosphorylation ; Tumor Suppressor Protein p53 ; genetics ; metabolism

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

Oncogene and antioncogene play contrary effects on the cell growth and proliferation controlling process, and cancer occurs when the presence of imbalance expression between them. That means there is yin-yang relationship between oncogene (yang) and antioncogene (yin), and also inside both of them. Taking the oncogene myc and antioncogene p53 for example, the yin gene p53 acts, in the yin side, to promote cell apoptosis and inhibit cell growth, while in the yang side, it facilitates for repairing the injured DNA to keep cell survival; the yang gene myc, promoting cell growth and proliferation in the yang side and inducing cell apoptosis in the yin side. To elucidate the yin-yang reactions between oncogene and antioncogene would be of important significance in the all-round and profound research of cancer.
Genes, Tumor Suppressor ; Humans ; Medicine, Chinese Traditional ; Neoplasms ; genetics ; Oncogenes ; genetics ; Proto-Oncogene Proteins c-myc ; metabolism ; Tumor Suppressor Protein p53 ; metabolism ; Yin-Yang

This study explored the double lethal effects of pEGFP-C1-wtp53/junB fusion gene on hepatocellular carcinoma (HCC) cells. wtp53/junB fusion gene was constructed and transformed into HepG2 cell line. Expression of KAI1 was detected by quantitative real-time PCR and Western blotting, cells apoptosis rate was detected by flow cytometry, proliferation of cells was detected byMTT chromometry, cell transmigration was detected by using transwell systems. The results showed that after transformation with pEGFP-C1-wtp53/JunB, the expression level of KAI1 protein was up-regulated, being 8.13 times the blank control group in HepG2 cells and significantly higher than 2.87 times which transformed with pEGFP-C1-JunB, 3.11 times which transformed with pEGFP-C1-wtp53 (P<0.001). Apoptosis rate of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly higher than that of other groups (P<0.001), and invasive ability of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly lower than other groups(P<0.001). It was concluded that the fusion gene of wtp53 and JunB could not only inhibit the growth of hepatoma cells and promote tumor cell apoptosis, but also suppress the invasive ability of tumor cells by up-regulating the expression of KAI1.
Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Hep G2 Cells ; Humans ; Liver Neoplasms ; genetics ; metabolism ; pathology ; Transcription Factors ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism