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Query: EC:3.1.3.1 (
alkaline phosphatase
)
47,916
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have developed new methodology for quantifying antibodies to the
p53 tumor suppressor
gene product in human serum. The assay involves solid-phase immobilization of a monoclonal anti-
p53
-specific antibody that is then reacted with a tumor cell line lysate containing mutant p53. The immunopurified
p53 antigen
acts as an immunosorbent for the serum
p53
antibodies that are then detected by reaction with a goat anti-human immunoglobulin G antibody labeled with
alkaline phosphatase
(
ALP
).
ALP
activity is then measured with enzymatically amplified time-resolved fluorometry. The developed assay has many advantages over the radioactively labeled techniques previously used. In a preliminary clinical study involving 790 patient sera, we have identified 16 positive samples (2%). Highest titers were observed in a patient with melanoma and two breast cancer patients. Further studies are needed to improve the sensitivity of this test and to evaluate its possible use for cancer diagnosis, prognosis or monitoring of therapy.
...
PMID:Antibodies to the p53 tumor suppressor gene product quantified in cancer patient serum with a time-resolved immunofluorometric technique. 147 69
A 36-year-old woman was referred to our hospital because of splenomegaly in February 1989. The leukocyte count was 55,500/microliter without hiatus leukemicus. The leukocyte
alkaline phosphatase
score was low (29). The bone marrow showed myeloid hyperplasia (24.8% myeloblasts) but no dysplastic change. The karyotype of the bone marrow cells was 46, XX and a diagnosis of Ph1 (-) CML was made. Treatment with VCR, 6MP and prednisolone made 7-month duration chronic phase, but the abnormal karyotype.[46, XX, i(17q)] gradually increased to 100% of bone marrow cells. The patient died in June 1990. The evidence that not only a BCR rearrangement but also messages of BCR/ABL fusion gene were negative made us able to differentiate this case from Ph1(-), BCR(+) CML. The addition of an i(17q) results in partial monosomy of 17q (17q13;
p53
gene) and partial trisomy of 17q (17q11.2-12;G-CSF gene). We examined the rearrangement of
p53
gene and G-CSF-dependent tumor cell growth in vitro, demonstrating one allelic loss of
p53
gene and independent cell growth on G-CSF respectively. It is thought that in Ph1 (-), BCR (-) CML as well as in Ph1 (+) CML, an i(17q) is related to the progression but not to the initiation of these leukemias. However the precise mechanism, including
p53
gene inactivation by point mutation, is still to be elucidated.
...
PMID:[i(17q) appearing in acute phase in Ph1-negative, BCR-negative CML]. 163 23
The potential significance of the phosphorylation of SV40 large T antigen for oligomers and complexes with the cellular
protein p53
was investigated. We observed that T antigen oligomers remain stable after enzymatic dephosphorylation by
alkaline phosphatase
up to 80%. Separate analysis of free and
p53
-bound T antigen revealed a considerably lower phosphorylation of the
p53
-bound subclass. Therefore, a simple correlation between the overall phosphorylation of T antigen and the formation of oligomers and T-
p53
complexes is highly unlikely.
...
PMID:Relationship of phosphorylation to the oligomerization of SV40 T antigen and its association with p53. 298 25
The oncogene product
p53
, isolated from SV3T3 cells where it forms a complex with simian virus 40 large tumor antigen (T antigen) in the nucleus, has been found to be phosphorylated at at least four distinct sites on the 390 amino acid protein. Separation of tryptic phosphopeptides has permitted identification of two sites as Ser-312 and Ser-389, and permitted analysis of the types of phosphate bonds. The peptide containing Ser-312 separates electrophoretically into three charged forms; two are resistant to dephosphorylation by both
alkaline phosphatase
and alkaline hydrolysis, suggesting a phosphodiester. The carboxyl-terminal phosphopeptide containing Ser-389 was
alkaline phosphatase
-resistant and liberated four ribonucleoside monophosphates upon base or RNase hydrolysis, suggesting that Ser-389 may be covalently linked to RNA. Phosphorylation of Ser-389 decreased markedly at the nonpermissive temperature in simian virus 40 tsA58-transformed cells, indicating a dependence on native T antigen function and a possible role in transformation by T antigen. Two additional phosphorylation sites, one involving serine and one involving threonine, probably reside in the amino-terminal segment of
p53
and appear to be peptide-phosphate monoesters.
...
PMID:Mapping of phosphomonoester and apparent phosphodiester bonds of the oncogene product p53 from simian virus 40-transformed 3T3 cells. 300 31
The codon 249 mutation specific expression of the
p53
gene was determined in 7 human hepatocellular carcinoma (HCC) cell lines. Two 20-base oligomers complementary to bases 872-891 of human
p53
cDNA with a single nucleotide difference in the third position of codon 249 were end-labelled with biotin-conjugated dATP using terminal deoxynucleotidyltransferase (TdT). The hybridized oligomer was visually detected in situ using streptavidin-
alkaline phosphatase
(AP) conjugate and AP substrate. Expression of the codon 249 mutant p53 was steady in PLC/PRF/5 and Mahlavu cells (derived from African patients), while Huh4, Huh6, Huh7 and HCC-M cells (derived from Japanese patients) expressed only the codon 249 wild-type
p53
. The transcripts of the
p53
gene were undetectable in Hep3B cells (derived from an American patient). Hybridizations of the codon 249 specific oligomers were specific to the
p53
transcripts, since the cells that expressed
p53
gene homogeneously were stained in the cytoplasm only by differential hybridization with a codon 249 specific oligomer; moreover, hybridization with a labelled oligomer non-complementary to the
p53
cDNA showed nuclear stainings. Thus, detection of the codon 249 mutant p53 mRNA by differential in situ hybridization is a specific method for studying the mutation-specific expression of the
p53
gene in liver cancers at the cellular level, while simultaneously visualizing the cell morphology. The results also support the notion that the
p53
gene codon 249 mutation may have etiological implications involving HCC from various geographic areas.
...
PMID:Differential in situ hybridization for determination of mutational specific expression of the p53 gene in human hepatoma cell lines. 756 52
Human osteosarcoma and fibrosarcoma cell lines were investigated for alterations in oncogenes, tumor suppressor genes, and growth factors, all of which have been implicated in tumor formation. Characterization of oncogenes that are involved in osteosarcoma formation, including the c-fos and c-myc oncogenes, indicated that all six osteosarcoma cell lines examined had 5- to 20-fold amplification of the c-myc oncogene, whereas neither of two fibrosarcoma cell lines c-myc amplification. Interestingly, only three of six osteosarcoma cell lines displayed altered c-myc immediate-early gene function. c-fos was found to be normal, both at the gene and functional levels, in all six osteosarcoma and both fibrosarcoma cell lines tested. Characterization of two tumor suppressor genes,
p53
and RB1, that have been implicated in osteosarcoma formation indicated that
p53
was altered in five of six osteosarcoma cell lines, whereas RB1 was altered in only two or six of these cell lines. Neither RB1 nor
p53
was found to be altered in the fibrosarcoma cell lines tested. An additional transformation marker, autocrine growth-factor production, was observed in all six osteosarcoma cell lines and both fibrosarcoma cell lines examined. Finally, the differentiation state of the osteosarcoma cell lines was investigated via the bone differentiation markers alkaline phosphates and osteocalcin. Alkaline phosphatase activity was observed in four of six osteosarcoma cell lines but not in the two fibrosarcoma cell lines examined. The
alkaline phosphatase
activity was a result of the expression of the bone/liver/kidney
alkaline phosphatase
isoform. High-level osteocalcin expression was observed in one of the osteosarcoma cell lines but not in the two fibrosarcoma cell lines examined, although all cell lines demonstrated low-level osteocalcin expression. Together, these data demonstrate that relatively undifferentiated osteosarcomas commonly display c-myc amplification,
p53
and RB1 mutation, and autocrine growth-factor production, all of which may play a role in osteosarcomagenesis.
...
PMID:Analysis of oncogenes, tumor suppressor genes, autocrine growth-factor production, and differentiation state of human osteosarcoma cell lines. 757 9
Immunohistochemical detection of the
p53
gene product by monoclonal antibodies has been shown to be associated with a poor clinical outcome in carcinomas of the breast and stomach. Because the prognostic relevance of
p53
immunostaining in lung cancer is still under debate, we studied the expression pattern and clinical significance of such staining in 73 patients with operable non-small-cell lung cancer.
p53
expression was detected on frozen sections with the use of monoclonal antibody p1801, which recognizes both the wild-type and mutant gene product (
alkaline phosphatase
-anti-
alkaline phosphatase
method). A tumor was considered
p53
positive if more than 1% of the tumor cells were stained. The
p53
expression pattern was compared with clinicopathologic parameters, and analysis of follow-up, based on the data of 65 patients, was done by a log rank test (median observation time, 780 days). Nuclear
p53
staining was detected in 33 of 73 non-small-cell lung cancers (45.2%). Comparison with clinicopathologic parameters demonstrated that the
p53 protein
was detected more frequently in younger patients (younger than 50 years, p = 0.014), whereas no correlation was found with sex, tumor differentiation, tumor histologic type, or TNM stage. Surprisingly, follow-up analysis revealed that
p53
staining was associated with an increased rate of disease-free survival, especially in patients with early stage tumor disease (p = 0.004) and in male patients (p = 0.023). Counter to previous studies in other solid tumors, immunocytochemical detection of
p53
expression does not predict a poor clinical outcome in non-small-cell lung cancer. In early-stage lung cancer it might be associated with an improved disease-free survival, which suggests that the majority of the detected protein inherits the wild-type tumor suppressor function.
...
PMID:Immunohistochemical detection of P53 protein is not associated with a poor prognosis in non-small-cell lung cancer. 777 84
Immunocytochemical methods were examined for their sensitivity in the detection of nuclear antigens (proliferating cell nuclear antigen, Ki-67 associated proliferative antigen and
p53 protein
) in the leukemic cells. A comparative study of the biotin streptavidin enhanced peroxidase technique, the biotin streptavidin enhanced
alkaline phosphatase
technique and the indirect immunoperoxidase technique showed that the indirect immunoperoxidase technique was more sensitive than the other techniques for detecting
p53 protein
. The results of several fixation methods demonstrated that formalin and methanol, formalin and ethanol (1:9) and buffered formalin acetone gave good results for detecting
p53 protein
. In the eosinophils and neutrophils the endogenous peroxidase reaction disappeared after microwave heating for over three minutes. Thus enzyme pre-blocking of blood smears could be omitted. Four solutions for microwave treatment were tested. Excellent antigen retrieval was obtained with pH6.4, pH7.4 phosphate buffer saline and pH6.0 citric acid. However, the nuclear antigens could not be retrieved and the positive reaction could not be obtained after the treatment with distilled water. The optimal microwave heating time was five to ten minutes. The indirect immunoperoxidase technique performed using microwave treatment under these optimal conditions may be potentially applicable for detecting low levels of nuclear antigens in the leukemic cells within conventional blood smears.
...
PMID:[Detection of nuclear antigen within the leukemic cells using immunocytochemical technique]. 778 70
The
p53
gene undergoes rearrangement in a high percentage of osteosarcomas, resulting in loss of its expression. A
p53
-null murine osteosarcoma cell line F6 was transfected with either a wild-type or a mutant p53 gene. Stably transfected cell lines were obtained, and their differentiation capabilities were compared in vitro with the parental cell line. Alkaline phosphatase and osteocalcin expression were measured as early and late differentiation markers, respectively. Induction of
alkaline phosphatase
expression was not affected by the presence of either
p53
gene, whereas osteocalcin expression was seen in cells containing the wild-type
p53
gene but not in the parental
p53
-null or mutant-expressing cell lines. That the induction of osteocalcin was intrinsically dependent on the presence of wild-type
p53
was also indicated by the use of a temperature-sensitive Val 135
p53
mutant at 32 degrees C; predominant expression of
p53
in the wild-type conformation resulted in osteocalcin expression. While the wild-type
p53
gene could suppress tumor formation in vivo, the tumors expressing the mutant p53 gene grew two to three times as large as the tumors that did not express
p53
. Therefore, the absence of end-point differentiation in bone due to
p53
rearrangements may contribute to the maintenance of the tumorigenic phenotype in osteosarcomas.
...
PMID:Dependence of induction of osteocalcin gene expression on the presence of wild-type p53 in a murine osteosarcoma cell line. 828 Mar 78
Elevated expression of the c-myc oncogene is a frequent finding in tumors and cell lines derived from carcinomas of the colon and rectum. In a previous study we demonstrated that the differentiation agent sodium butyrate causes a rapid reduction in the expression of c-myc RNA in the rectal carcinoma cell line SW837. This effect was blocked by inhibitors of protein synthesis, suggesting that butyrate causes the induction of an activity that has a negative effect on c-myc expression. In the present work we demonstrate that the rapid decrease in the level of c-myc RNA, upon treatment of SW837 cells with 2 mM butyrate, is followed by a slower decrease in the level of
p53
RNA and an increase in the RNA levels for fibronectin and a placental type
alkaline phosphatase
. Using in vitro elongation of nascent transcripts to measure transcription and actinomycin D chase experiments to measure RNA stability, we show that the reduction in expression of c-myc RNA is due to an increase in the block to transcriptional elongation, rather than a decrease in transcriptional initiation or an increase in degradation of the RNA. We conclude that sodium butyrate induces an activity that increases the transcriptional block in SW837 cells, and that regulation of transcriptional elongation is an important mechanism for regulating c-myc expression in this cell type. A shift in relative usage of the two major promoters in the c-myc gene accompanies the reduction in expression. The potential significance of this finding with respect to transcriptional elongation is discussed. Mutations in the exon 1/intron 1 boundary region of the c-myc gene cause an increase in transcriptional elongation in Burkitt lymphoma. We sequenced this region in a series of cell lines derived from colorectal carcinomas, all of which had an elevated level of c-myc expression, to determine if a similar mutational mechanism is at work in this disease. All of the lines examined had a normal c-myc DNA sequence, suggesting that the deregulation of c-myc expression in colon cancer is not due to a cis mutation in this region.
...
PMID:Sodium butyrate causes an increase in the block to transcriptional elongation in the c-myc gene in SW837 rectal carcinoma cells. 837 1
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