Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ataxia-telangiectasia (AT) syndrome (cerebellar ataxia, oculocutaneous telangiectasias, immunodeficiency, susceptibility to infections, and neoplasia) is associated with cyto- and nucleomegaly in several organ systems. Our aim was to determine (1) whether such cellular abnormalities in the pituitary selectively involve specific cell types, and (2) the proliferation and DNA ploidy status of such cells. Three AT autopsy pituitaries were studied by histology, immunohistochemistry (pituitary hormones, MIB-1, p53 protein), in situ hybridization (pituitary hormones), and Feulgen stain image analysis for ploidy. Results indicated that, in adenohypophyses the scattered pleomorphic, bizarre nuclei were mainly those of somatotrophs and corticotrophs, growth hormone (GH), or adrenocorticotropic hormone (ACm) immunoreactive and expressing the GH or ACTH gene, respectively. Cyto- and nucleomegaly were less frequent in other secretory cells but were also noted in pituicytes of the posterior lobe. Affected cells were immunonegative for MIB-1 and for p53 protein. Image morphometric DNA analysis showed the bizarre cells to be aneuploid with complex histogram patterns, including many nuclei with DNA contents >8 n. No adenomas were found. We conclude that in AT adenohypophyseal cells with cyto- and nucleomegaly, as well as pleomorphism, synthesize and store adenohypophyseal hormones, mainly GH or ACTH. They and affected pituicytes are nonproliferative and are aneuploid.
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PMID:Pituitary Changes in Ataxia-Telangiectasia Syndrome: An Immunocytochemical, In Situ Hybridization, and DNA Cytometric Study of Three Cases. 1211 23

We investigated the effects of growth hormone-releasing hormone (GHRH) antagonists, JV-1-65 and JV-1-63, and bombesin/gastrin-releasing peptide (BN/GRP) antagonist RC-3940-II on DMS-153 human small cell lung carcinoma xenografted into nude mice. Treatment with 10 microg/day JV-1-65 or RC-3940-II decreased tumor volume by 28% (P < 0.05) and 77% (P < 0.01), respectively, after 42 days compared with controls. Combination of JV-1-65 and RC-3940-II induced the greatest inhibition of tumor proliferation (95%; P < 0.01), suggesting a synergism. Western blotting showed that the antitumor effects of these antagonists were associated with inhibition of the expression of the mutant tumor suppressor protein p53 (Tp53). Mutation was detected by sequence analysis of the p53 gene at codon 155: ACC [Thr] --> CCC [Pro]. Combination of JV-1-65 and RC-3940-II decreased the levels of mutant p53 protein by 42% (P < 0.01) compared with controls. JV-1-65, JV-1-63, and RC-3940-II, given singly, reduced mutant p53 protein expression by 18-24% (P < 0.05). Serum insulin-like growth factor (IGF)-I levels were diminished in animals receiving GHRH antagonists. mRNA levels for IGF-II, IGF receptor-I, GRP receptor, and EGF receptor in tumors were significantly decreased by combined treatment with JV-1-65 and RC-3940-II. DMS-153 tumors expressed mRNAs for GHRH and GHRH receptor splice variants 1 and 2, suggesting that GHRH could be an autocrine growth factor. Proliferation of DMS-153 cells in vitro was stimulated by GRP and IGF-II and inhibited by JV-1-65. This study indicates that GHRH antagonists and BN/GRP antagonist inhibit the growth of DMS-153 small cell lung carcinoma concomitantly with the expression of mutant Tp53, which might uncouple the signal transduction pathways for cell growth stimulation.
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PMID:Inhibition of mutant p53 expression and growth of DMS-153 small cell lung carcinoma by antagonists of growth hormone-releasing hormone and bombesin. 1466 Jul 94

A mammary tumor cell line, designated MTCL, was successfully established from a mouse primary mammary tumor (MTP). The MTCL cells retain cytokeratin and both estrogen receptor (ER) and progesterone receptor (PR) in vitro. In vitro exposure of MTCL cells to progesterone causes a decrease in the cellular (3)H-thymidine uptake, indicating an inhibition by progesterone on MTCL cellular deoxyribonucleic acid synthesis, whereas exposure of the cells to a high dose of estrogen (15 pg/ml) for 48 h causes an increase of (3)H-thymidine uptake. We inoculated both MTP or MTCL tumor cells into normal cycling female C(3)HeB/FeJ mice and demonstrated that the post-resection metastatic recurrence of MTCL tumors, like the original MTP tumors, depends on the time of tumor resection within the mouse estrous-cycle stage. Both MTCL and MTP tumors have similar histological appearances with the exception of less extensive tumor necrosis and higher vascularity in MTCL tumors. Equivalent levels of sex hormone receptors (ER alpha, ER beta, and PR), epithelial growth hormone receptors (Her2/neu, EGFR1), tumor suppressors (BRCA1, P53), and cell apoptosis-relevant protein (bcl-xl) were found in these in vivo tumors by immunohistochemistry. Cyclin E protein, however, was significantly higher in MTP tumors compared with MTCL tumors. Our results indicate that MTCL cells retain many of the biologic features of the original MTP primary tumor cells, and to our knowledge, it is the first in vitro cell line that has been shown to maintain the estrous-cycle dependence of in vivo cancer metastasis.
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PMID:Creation of a stable mammary tumor cell line that maintains fertility-cycle tumor biology of the parent tumor. 1516 41

Genetic interventions that accelerate or retard aging in mice are crucial in advancing our knowledge over mammalian aging. Yet determining if a given intervention affects the aging process is not straightforward since, for instance, many disease-causing mutations may decrease life span without affecting aging. In this work, we employed the Gompertz model to determine whether several published interventions previously claimed to affect aging in mice do indeed alter the aging process. First, we constructed age-specific mortality tables for a number of mouse cohorts used in longevity experiments and calculated the rate at which mortality increases with age. Estimates of age-independent mortality were also calculated. We found no statistical evidence that GHRHR, IGF1R, INSR, PROP1, or TRX delay or that ATM + TERC, BubR1, klotho, LMNA, PRDX1, p53, WRN + TERC, or TOP3B accelerate mouse aging. Often, changes in the expression of these genes affected age-independent mortality and so they may prove useful to other aspects of medicine. We found statistical evidence that C/EBP, MSRA, SHC1, growth hormone, GHR, PIT1, and PolgA may influence aging in mice. These results were interpreted together with age-related physiological and pathological changes and provide novel insights regarding the role of several genes in the mammalian aging process.
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PMID:The influence of genes on the aging process of mice: a statistical assessment of the genetics of aging. 1546 29

Benzene toxicity has long been thought to be due to its metabolites including reactive oxygen species (ROS). However, the major toxicological effect of benzene in wild-type mice carrying normal alleles of the p53 gene appears to be the significant perturbation of cell cycle regulation, possibly via an indirect signaling pathway. Other prominent genotoxic cellular damage can occur in the absence of cell cycle arrest in p53 gene deficiency. The suppression of cell cycle is clearly detected using a tool for stem-cell-specific cell cycle observation by the BU-UV method. Cells (including hemopoietic progenitor cells) in S-phase are labeled in vivo with bromodeoxyuridine (BrdU) and then exposed to near-ultraviolet (UV) light to kill cells that incorporated BrdU. The target fraction, the S-phase, is then evaluated on the basis of decreased numbers of hemopoietic colonies formed in assays such as for granulomacrophage colony-forming units (CFU-GM). Benzene toxicity was found to be more prominent in the primitive stem-cell compartment, as first suggested more than 20 years ago. Interestingly, when one examines the stem-cell-specific steady-state gene expression profiling, several key genes associated with benzene exposure are specifically identified, including CYP2E1. Benzene toxicity was found to be mediated by aryl hydrocarbon receptor (AhR) at an expression level; thus, the effect of benzene can be detected in nature at lower levels in the stem-cell compartment than expected. Alterations in gene expression profiles compared with those in steady-state gene expression profiles in the stem-cell compartment may elucidate the mechanism underlying benzene toxicity. Functional gene expressions after benzene exposure are not always detected, because their phenotypic expressions are often masked by the balance of expression of genes participating in various pathways of homeostasis, for example, p53. Thus, the actual expressions of the above-mentioned cell cycle-related genes may not be clearly detected. However, when one examines the genes after benzene exposure without p53 gene participation (i.e., p53 was knocked out), various cell cycle-related genes expressed during and after benzene exposure are identified, such as cyclin B1, cyclin D3 and growth hormone in the bone marrow. Since age-related impairments of p53 gene function in somatic cells are known, the possible alteration of those genes would be based not only on a theoretical model, but possible risks posed on the elderly should also be taken into consideration.
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PMID:p53-dependent gene profiling for reactive oxygen species after benzene inhalation: special reference to genes associated with cell cycle regulation. 1593 13

The incidence and prevalence of premalignant and malignant skin lesions including squamous cell carcinoma (SCC) of the skin are increasing worldwide. The aim of the study was to determine TP53, Bcl-2 and growth hormone receptor (GHR) expression in SCC and to investigate relative importance of these proto-oncogenes in its biological behavior. Expression of TP53, Bcl-2 and GHR was determined by immunohistochemistry in 27 SCC specimens and adjacent perilesional skin. The relative proportion of immunoreactive cells was counted with semiquantitative method. TP53 positivity was detected in 24 (89%), Bcl-2 in 18 (67%) and GHR in 25 (93%) of 27 SCC specimens investigated. In comparison with perilesional skin, TP53 and GHR positivity was significantly increased, and Bcl-2 positivity significantly decreased in SCC. Increased TP53 expression in SCC lesions implies that Tp53 mutation is an early and crucial event in its development. Increased GHR expression suggests a role of growth hormone in the development of SCC.
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PMID:TP53, Bcl-2 and growth hormone receptor expression in cutaneous squamous cell carcinoma. 1635 91

The p53 tumor suppressor induces cellular growth arrest and apoptosis in response to DNA damage by transcriptionally activating or repressing target genes and also through protein-protein interactions and direct mitochondrial activities. In 1995, insulin-like growth factor binding protein (IGFBP)-3 was identified as one of the genes transcriptionally activated by p53. IGFBP-3 is one of six closely related IGFBP's, with additional IGFBP-related proteins belonging to the IGFBP superfamily. Here we show that IGFBP-2 is also a p53 target. Like IGFBP-3, IGFBP-2 secretion is reduced when p53+/+ lung cancer cells are transfected with human papillomavirus E6, which targets p53 for degradation. IGFBP-2 mRNA is induced by irradiation in vivo in a p53-dependent manner. p53 protein binds IGFBP-2 intronic sequences in an electrophoretic mobility shift assay, and activates transcription in a luciferase assay. Loss of IGFBP-2 inhibits the ability of p53 to inhibit the activation of extracellular signal-regulated kinase (ERK)1 by IGF-I. Thus, p53 effects on the IGF axis are more complex than previously appreciated, and overall transform the axis from IGF-mediated mitogenesis to growth inhibition and apoptosis. This has significant implications for how growth hormone and IGF-I can induce growth without also inducing cancer.
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PMID:Insulin-like growth factor factor binding protein-2 is a novel mediator of p53 inhibition of insulin-like growth factor signaling. 1710 89

The expression of growth hormone-releasing hormone (GHRH) and its receptors has been demonstrated in peripheral tissues as well as CNS. Recently, the functional splice variant SV1 of GHRH receptor was identified in various human cancers and cancer cell lines. Although antineoplastic activity of GHRH antagonists has been clearly demonstrated, the mechanism of action is incompletely understood. The objective of this study was the investigation of direct anti-proliferative effect of GHRH antagonist MZ-5-156 on HEC-1A human endometrial cancer cell line and the elucidation of underlying mechanisms. RT-PCR revealed the expression of mRNA for GHRH and SV1 of GHRH receptor in HEC-1A cells. MZ-5-156, at concentrations between 10(-7) and 10(-5) M, had a dose-dependent antiproliferative effect on HEC-1A cells, as determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, (MTS) assay. Hoechst 33342 staining and flow cytometric analysis indicated that MZ-5-156, at 10(-6) M, induced apoptosis in HEC-1A cells after 48 h of treatment. Western blot analysis of apoptosis-related proteins demonstrated that treatment with MZ-5-156 (10(-6) M) for 48 h significantly increased the protein levels of Fas, phospho-p53 (Ser46), p53AIP1 (p53-regulated Apoptosis-Inducing Protein 1), and caspase-8, -9, and -3, and decreased the protein level of Bcl-2. These results demonstrate that MZ-5-156 can directly inhibit the proliferation of human endometrial cancer cells, which express mRNA for GHRH and SV1 of GHRH receptor, presumably through the induction of p53-dependent apoptosis coupled with the up-regulation of Fas, phospho-p53 (Ser46), p53AIP1, and caspase-8, -9, and -3, and the down-regulation of Bcl-2.
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PMID:Cellular mechanisms of growth inhibition of human endometrial cancer cell line by an antagonist of growth hormone-releasing hormone. 1829 36

The last several years have seen a significant increase in our understanding of the molecular and biochemical changes associated with pituitary tumour initiation and progression. The combined data, from several groups, now allow a tentative map to be drawn showing that reduction to hemizygosity at several chromosomal loci (10q, 11q13 and 13q) is associated with the transition to the invasive phenotype, while loss on chromosome 9p and methylation of the tumour suppressor gene p16 appear to occur early in pituitary tumorigenesis. Changes in the expression/status of several genes and/or proteins including p53, the cAMP response element-binding factor (CREB), growth hormone-releasing hormone (GHRH), nm23, p16 and p27 have also been identified along this multi-step pathway. Prospective studies will determine whether these markers are truly predictive of subsequent tumour behaviour and can be used to aid clinical management in a manner not possible when current histological criteria are used.
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PMID:Molecular genetics of pituitary tumours. 1840 30

Hypothalamic growth hormone-releasing hormone (GHRH) controls the release of growth hormone and acts as a growth factor in various tumors. Potent antagonistic analogues of GHRH have been synthesized that strongly suppress the growth of diverse cancers through several mechanisms. However, the influence of GHRH antagonists on the redox (reduction/oxidation) status of cancers has not been investigated. Cellular generation of reactive oxygen species (ROS) is central to redox signaling and is implicated in the initiation, development, and progression of cancer. In this study, we evaluated by Western blot the effects in vitro of GHRH and its antagonist JMR-132 on proliferating cell nuclear antigen, tumor suppressor protein p53, transcription factor NF-kappaB p50 and its phosphorylated form, caspase 3, and cleaved caspase 3 in the LNCaP human prostate cancer cell line. GHRH stimulated and GHRH antagonist inhibited the expression of the major antioxidant enzymes, as well as the expression of COX 2 and cytochrome c oxidase IV, which are enzymes involved in the generation of ROS. GHRH augmented and GHRH antagonist suppressed lipid and protein oxidative stress markers, as well as the intracellular generation of ROS. In all these tests, GHRH antagonists exerted strong antioxidant activity. Because the metabolism of ROS and oxidative stress have been associated with initiation and progression of not only prostate tumors but also other malignancies, our findings reinforce previous experimental evidence that GHRH antagonists could be useful for cancer therapy.
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PMID:Antioxidant activity of growth hormone-releasing hormone antagonists in LNCaP human prostate cancer line. 1907 33


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