AIMTo develop a simple, fast and inexpensive approach as well as an instrument for detection of gene mutation.

METHODSPyrosequencing based on bioluminometry assay was employed to detect gene mutation. Pyrosequencing is a method of sequencing by synthesis step-by-step using four enzymes, DNA-polymerase, ATP sulfurylase, luciferase and apyrase. The signal was produced by detecting pyrophosphate released during a dNTP incorporation. For mutation detection, a DNA fragment was amplified by PCR at first, followed by a single-stranded DNA preparation. In the second step, a short primer was annealed to the position just before the mutation point. Finally, specific dNTPs were added in terms of the template sequence. The mutation species can be readily determined by the sequence.

RESULTSA new instrument was developed for gene mutation detection by pyrosequencing. To iteratively inject small amount of each dNTP for the sequencing reaction, capillaries were used to connect dNTP reservoirs and the reaction chamber. Each dNTP was delivered by adding a gas pressure on the top of a corresponding dNTP reservoir, by which 0.2 microL of dNTP can be exactly added each time. It was theoretically proved that undesired liquid seep through the capillary did not affect the sequencing reactions in pyrosequencing. In addition, the three possible variants (wildtype, mutant and heterozygote) of a mutant point Cys275Ser in P53 gene exon 8 were determined by pyrosequencing using the instrument. A simple method was also described for rapidly distinguishing the type of a variant.

CONCLUSIONThe developed method is very simple, and the corresponding instrument is inexpensive and easy to operate, which can be used to detect many types of mutation.

Exons ; genetics ; Genes, p53 ; genetics ; Humans ; Luminescent Measurements ; Point Mutation

The P53 gene has the important functions including induction of apoptosis, regulation of cell cycle, repair of DNA damage. The mutation of the P53 gene exists in more than 50% of human tumors and 13% of hematological malignancies. The P53 gene abnormality is closely related with the clinical course and prognosis of leukemia. The P73 or P63 gene, the member of the P53 family not only possesses similar to P53 activity of inducing apoptosis, activating transcription, but also plays different biological effects according to protein structural diversity, and even antagonises the function of the P53 gene. Researchers found that P73 or P63 gene also has the dual characteristics of the tumor suppressor and oncogene, and shows different expression and function in different types, different stages of leukemia. In this article, P53 family (P53, P73, P63) gene structure, biological function and the relationship of the three genes with the course, prognostic outcome, treatment and other clinical features of the leukemia are reviewed.
Gene Expression Regulation, Neoplastic ; Genes, p53 ; Humans ; Leukemia ; diagnosis ; genetics ; pathology ; Tumor Suppressor Protein p53 ; genetics

Adult ; Cytogenetics ; Genes, p53 ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Prognosis ; Tumor Suppressor Protein p53/genetics*

OBJECTIVETo explore the significance and the role of the p53 gene mutation in the exon 4 to 8 in keloid fibroblasts.

METHODSTissue samples from twelve patients with keloid and twelve hyperplastic scar respectively were harvested for in vitro culture of fibroblasts, and normal skin samples from the same patients were employed as the control. Polymerase chain reaction-based single-strained conformational polymorphism (PCR-SSCP) and DNA sequencing were employed to detect p53 gene mutations of the fibroblasts.

RESULTSThe points and frameshift mutations in the exon 4, 5, 6, 7 of p53 gene were identified in 9 of the 12 keloid tissue samples. No p53 gene mutation was detected in all hyperplastic scar and normal skin samples.

CONCLUSIONp53 gene mutation might play an important role in the formation and development of keloids.

Female ; Fibroblasts ; metabolism ; Genes, p53 ; Humans ; Keloid ; genetics ; Male ; Mutation

Mantle cell lymphoma(MCL) is an independent uncommon subtype of B-cell non-Hodgkin's lymphoma (NHL) according to World Health Organization classification of hematopoietic and lymphoid tissue tumors. The genetic hallmark of MCL is the chromosomal translocation t(11;14)(q13;q32) that leads to upregulation of cyclin D1, an important regulator of the G(1) phase in the cell cycle. This genetic aberration is virtually present in all cases of MCL. It is characterized by distinct clinical features and outcome which is affected by a series of additional genetic aberration including the genomic guardian-P53 gene. This article reviews the effects of P53 gene aberrations including P53 deletion, mutation and their mutual relationship in MCL, and novel therapeutic regimens for MCL patients with P53 aberrations.
Gene Deletion ; Genes, p53 ; Humans ; Lymphoma, Mantle-Cell ; genetics ; Mutation

Mutations in p53 signal pathway are found in nearly all types of cancers, indicating its close relationship with human malignant tumors. Wide type p53 is a potent tumor suppressor, whose biological effects are largely due to its function as a transcriptional regulator. MicroRNAs (miRNAs) is an important class of noncoding regulatory RNA molecules, with profound impact on a wide array of biological processes, regulating both messenger RNA (mRNA) translation and decay by the combination of target mRNA. The latest studies found that miRNAs are important molecules during the modulation of protein expression by activation of p53. The miRNA biosynthesis, function and the research progress in p53 gene signal pathway are reviewed.
Gene Expression Regulation ; Genes, p53 ; Humans ; MicroRNAs ; genetics ; Signal Transduction

Animals ; Genes, BRCA2 ; Genes, erbB-1 ; Genes, erbB-2 ; Genes, p16 ; Genes, p53 ; Genes, ras ; Genetic Predisposition to Disease ; genetics ; Humans ; Pancreatic Neoplasms ; classification ; genetics ; pathology

Animals ; Apoptosis ; genetics ; Genes, p53 ; genetics ; Liver Neoplasms, Experimental ; genetics ; pathology ; Rats ; Transfection ; Tumor Cells, Cultured

Adenoviridae ; genetics ; Genes, p53 ; Genetic Therapy ; methods ; Genetic Vectors ; Humans ; Neoplasms ; therapy ; RNA Interference ; Tumor Suppressor Protein p53 ; genetics

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