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)

The proliferation of non-neoplastic T lymphocytes is regulated, in part, by the coordinated expression of genes encoding T-cell growth factor (interleukin 2, IL2), IL2 receptors (IL2R), and transferrin receptors (TFR). In addition to growth factors and their receptors, protooncogenes may regulate lymphocyte proliferation. We used cloned cDNAs homologous to 21 different protooncogenes to screen for their expression at the mRNA level in human peripheral blood mononuclear cells (PBMC) stimulated with the mitogenic lectin phytohemagglutinin (PHA), and we compared the time course of accumulation of mRNAs for these protooncogenes to that of mRNAs for the IL2, IL2R, TFR, and histone H3 genes. mRNAs for c-abl, c-ets, c-yes, and N-ras were present in unstimulated PBMC. After stimulation of PBMC by PHA, we detected marked increases within 10 min in the levels of mRNA for c-fos and c-myc; within 6 hr for IL2 and IL2R mRNAs; within 14 hr for c-myb, p53, N-ras, and TFR mRNAs; and within 24-36 hr for H3 mRNA. Expression of c-abl, c-ets, and c-yes increased gradually following stimulation with PHA. None of the other protooncogenes tested was expressed in PBMC. Addition of the protein synthesis inhibitor cycloheximide, before the addition of PHA to cultures, abolished the PHA-induced accumulation of mRNAs for c-myb, N-ras, and TFR, but not of mRNAs for c-fos, c-myc, IL2, and IL2R. These data indicate that c-fos, c-myc, IL2, and IL2R belong to a group of genes expressed early, whereas c-myb, N-ras, and TFR belong to a group of genes expressed later in PHA-activated PBMC, and that the products of the c-fos and c-myc protooncogenes are not required for expression of IL2 or IL2R genes. Addition of purified IL2 augmented the expression of the later-expressed genes c-myb, p53, N-ras, and TFR in PHA-stimulated cultures of PBMC, as well as of the early genes c-myc and IL2R, but not of c-fos and IL2, thus suggesting that PHA and IL2 stimulate the expression of overlapping, but nonidentical, sets of genes in PBMC.
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PMID:Sequential expression of protooncogenes during lectin-stimulated mitogenesis of normal human lymphocytes. 301 40

Within the past few years, the measurement of serum and tissue markers has had an increasing influence on clinical decisions about initial treatment and follow-up. Lung cancer illustrates the types and importance of these various markers. This review presents data concerning the most studied and interesting markers in non-small cell (NSCLC) and small cell lung cancer (SCLC). CEA, TPA, SCC-Ag, CYFRA 21-1, ferritin, CA19-9, CA50, CA242, H-K-N-ras mutations and p53 mutation seem to be the most prolific in NSCLC, while NSE, BN/GRP, CK-BB, NCAM, IL-2R, IGF-I, transferrin, ANP, mAb (cluster 5), Le-y and c-N-L-myc mutation are markers in SCLC patients. Some of these serum markers might be useful adjuncts for monitoring response to therapy, including early detection of tumour reactivation to allow curative therapy and rapid detection of treatment failure to allow change of the regimen. The study of these markers also may lead to a better understanding of the biological characteristics of lung cancer. The information derived from these biological studies represents the most promising avenue towards new treatment strategies, as well as attempts at secondary prevention.
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PMID:Clinical tumour markers in lung cancer. 753 17

Technological developments have made possible extension of polymerase chain reaction (PCR) analysis to individual cells to localize DNA/RNA with non-radioactive labels at the light microscopic level. This approach, in situ PCR, is particularly useful in resolving low-frequency message expression in mixed populations of cells and tissues. We have established a working protocol for direct in situ PCR and have utilized several controls to validate our results. In this report we outline the procedures for detecting either DNA or RNA in a rapid and reproducible manner. We evaluate the sequential steps required for this analysis, such as protease hydrolysis, DNAse digestion, "hot start" capabilities, and detection methods. We have applied these methods in several applications, including detection of the p53 gene in human tumor samples, localization of insulin-like growth factor-IA mRNA in cell lines with low levels of expression, and distribution of transferrin mRNA in lung cancer cell lines and tumors. We demonstrate from this study that the in situ PCR technique is an investigative approach capable of detecting specific DNA/RNA sequences at the cellular level and of identifying cells with low levels of mRNA expression.
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PMID:Non-radioactive localization of nucleic acids by direct in situ PCR and in situ RT-PCR in paraffin-embedded sections. 754 78

We studied the occurrence of a p53 mutation along passages stored as frozen vials during establishment of a nontumorigenic human mammary epithelial cell line HMT-3522. Mutations were identified by a PCR-SSCP approach using DNA as a template. The mutation, a nonconservative nucleotide substitution at codon 179 changing a histidine into an asparagine, appeared between passages 51 and 63 and was concommitant to a change in growth conditions. Cells were no longer grown on collagen coat and cell growth was not responsive to insulin, transferrin, or hydrocortisone anymore. To assess if the mutation was an early or a late event during cell line evolution we put a vial of cells frozen at passage 30 back into culture and tested for the appearance of a p53 mutation along newly produced passages. The same mutation (His to Asp at codon 179), as previously identified, reemerged between passages 48 and 52, thus indicating that the mutation was preexisting in passage 30 and gradually selected out because of the growth advantage it conferred. In order to gain in sensitivity we used a RFLP approach on PCR fragments which allowed us to detect the mutation as early as passage 44. Hence it took 14 passages (approx 50 cell doublings) for the mutated cells to become detectable and another 9 passages (33 generations) to overgrow the wild-type component of the population. We calculated that the mutated cells acquired a growth advantage which allowed them to cycle 1.2 +/- 0.05 faster than wild type. Computer simulations were consistent with the mutation appearing at passage 20.
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PMID:Gradual selection of a cellular clone presenting a mutation at codon 179 of the p53 gene during establishment of the immortalized human breast epithelial cell line HMT-3522. 798 76

Lung cancer is the leading cause of cancer death in the United States. Small cell lung cancer (SCLC) accounts for 20% to 25% of all bronchogenic carcinoma and is associated with the poorest 5-year survival of all histologic types. SCLC differs in its etiologic, pathologic, biologic, and clinical features from non-SCLC, and these differences have translated to distinct approaches to its prevention and treatment. Compared with other histologic types of lung cancer, exposures to tobacco smoke, ionizing radiation, and chloromethyl ethers pose a substantially greater risk for development of SCLC. The histologic classification of SCLC has been revised to include three categories: (1) small cell carcinoma, (2) mixed small cell/large cell, and (3) combined small cell carcinoma. Ultrastructurally, SCLC displays a number of neuroendocrine features in common with pulmonary neuroendocrine cells, including dense core vesicles or neurosecretory granules. These dense core vesicles are associated with a variety of secretory products, cell surface antigens, and enzymes. The biology of SCLC is complex. The activation of a number of dominant proto-oncogenes and the inactivation of tumor suppressor genes in SCLC have been described. Dominant proto-oncogenes that have been found to be amplified or overexpressed in SCLC include the myc family, c-myb, c-kit, c-jun, and c-src. Altered expression of two tumor suppressor genes in SCLC, p53 and the retinoblastoma gene product, has been demonstrated. Cytogenetic and molecular evidence for chromosomal loss of 3p, 5q, 9p, 11p, 13q, and 17p in SCLC has intensified the search for other tumor suppressor genes with potential import in this malignancy. Bombesin/gastrin-releasing peptide, insulin-like growth factor I, and transferrin have been identified as autocrine growth factors in SCLC, with a number of other peptides under active investigation. Several mechanisms of drug resistance in SCLC have been described, including gene amplification, the recently described overexpression of multi-drug resistance-related protein (MRP), and the expression of P-glycoprotein. The classic SCLC staging system has been supplanted by a revised TNM staging system where limited disease and extensive disease are equivalent to the TNM stages I through III and stage IV, respectively. Therapeutically, recent strategies have attained small improvements in survival but significant reductions in the toxicities of chemotherapeutic regimens. Presently, the overall 5-year survival for SCLC is 5% to 10%, with limited disease associated with a significantly higher survival rate.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Small cell lung cancer: etiology, biology, clinical features, staging, and treatment. 839 98

Embryonic fibroblasts derived from p53-deficient transgenic mice showed distinct phenotypic and biological changes in vitro. In this study, we investigated the possible impact of p53 on the synthesis of other cellular proteins by comparing the protein profiles of p53 null (-/-), hemizygous (+/-) and p53 positive homozygous (+/+) cells using high resolution two dimensional gel electrophoresis. A total of more than 850 proteins were detected in each cell line labeled with 35S-methionine by using computerized image analysis, and a number of proteins were detected with qualitative or quantitative changes in p53-/- cells and to a lesser extent in p53+/- cells. Specifically, seven proteins became undetectable, and no new proteins were detected in p53-/- cells. Neither newly expressed nor absent proteins were detected in p53+/- cell line. Quantitatively, a total of 97 and 59 proteins were detected with significant quantitative changes (3 fold or greater) in p53-/- and p53+/- cells, respectively. Generally, most protein changes fell into one of the following four patterns: 1) progressively decreased synthesis in cells from p53+/+ to p53+/- to p53-/- cells; 2) progressively increased synthesis in cells from p53+/+ to p53+/- to p53-/- cells; 3) decreased synthesis only in p53-/- cells; and 4) increased synthesis only in p53-/- cells. A 70 kD heat shock protein (Hsp 70) was identified and showed a greater than 1,000-fold increase in p53-/- cells compared to that in p53+/+ cells. Transferrin, tropomyosin, and proliferating cell nuclear antigen (PCNA) have also been identified and measured in this study. Synthesis of transferrin and tropomyosin was significantly increased or decreased, respectively in p53-/- cells, whereas expression of PCNA showed no significant change in p53-/- cells despite their much higher (3-4 times) proliferation rate than the other two cell lines (p53+/+ and p53+/- cells). We conclude that disruption of a single important gene, p53, results in a cascade of protein changes which are related to the loss of p53 mediated negative growth effects on cell cycle control.
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PMID:Altered protein synthesis in p53 null and hemizygous transgenic mouse embryonic fibroblasts. 853 50

Wild-type (wt) p53 DNA was transfected into the radioresistant human cell line JSQ-3, established from a squamous cell carcinoma of the head and neck (SCCHN), using a transferrin-liposome system, and the ability of the introduced wt p53 to sensitize the transfected JSQ-3 cells to ionizing radiation was examined. Transferrin increased the in vitro transfection efficiency of cationic liposomes up to 70-80% in JSQ-3 cells, representing a 6- to 10-fold increase over liposome transfection alone. The exogenous wt p53 was expressed at high levels in transferrin-liposome-DNA-transfected cells and resulted in the reversion of the radioresistant phenotype of the JSQ-3 cells in a DNA dose-dependent manner. The D10 values were reduced from 6.36 +/- 0.54 Gy to 4.13 +/- 0.06 Gy, a value in the radiosensitive range. In vivo, the intratumoral injection of the transferrin-liposome system resulted in a higher number of transfected tumor cells in the JSQ-3 induced nude mouse xenografts when compared with transfection by liposome alone. The results indicate that the combination of p53 replacement gene transduction, mediated by the relatively safe transferrin-liposome system, and conventional ionizing radiation may provide a more effective treatment for head and neck cancer.
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PMID:Transferrin-liposome-mediated p53 sensitization of squamous cell carcinoma of the head and neck to radiation in vitro. 905 21

Expression of 18 genes was examined at 8 different time points between 1 h and 28 days following cryogenic rat brain injury. The genes include thymidine kinase (TK), p53 tumor suppressor, c-fos, renin, myelin basic protein (MBP), proteolipid protein (PLP), transferrin, transferrin receptor, platelet-derived growth factor A (PDGF A), platelet-derived growth factor B (PDGF B), platelet-derived growth factor receptor alpha (PDGF alpha receptor), platelet-derived growth factor receptor beta (PDGF beta receptor), glial fibrillary acidic protein (GFAP), transforming growth factor-beta 1 (TGF-beta 1), basic fibroblast growth factor (bFGF), fibroblast growth factor receptor-1 (FGF-R1), insulin-like growth factor-1 (IGF-1), and somatostatin. Time courses of gene expression were determined for RNAs derived from hippocampus and cortex. Genes were divided into categories based upon those in which statistically significant changes in expression were first observed at or before 24 h (early genes) and those in which changes were first observed at or after 72 h (late genes). In the present model, many genes demonstrate elevated RNA levels in the cortex prior to hippocampus, following injury. RNAs transcribed from late genes tend to be elevated concurrently in cortex and hippocampus.
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PMID:Temporal changes in gene expression following cryogenic rat brain injury. 964 55

The products of the tumor suppressor genes are considered to function as specific inhibitors of tumor cell growth. In this communication, we present evidence to show that these proteins inhibit tumor cell proliferation by participating in the activation of tumor cell differentiation. The ML-1 human myeloblastic leukemia cells used in this study proliferate when treated with insulin-like growth factor I and transferrin but differentiate to monocytes when exposed to tumor necrosis factor alpha or transforming growth factor beta1, or to macrophage-like cells when treated with both these cytokines. Initiation of proliferation but not of differentiation was followed by a 20- to 25-fold increase in the nuclear level of the DNA polymerase-associated processivity factor PCNA and of the proliferation-specific transcription factor E2F1. In contrast, induction of differentiation but not of proliferation was followed by a 25- to 30-fold increase in the nuclear level of the tumor suppressor proteins p53 (wild type), pRb, and p130/Rb2 and of the p53-dependent cyclin kinase inhibitor p21/Cip1. p53 and p21/Cip1, respectively, inhibit the expression and activation of PCNA, whereas p130 and pRb, respectively, inhibit the expression and activation of E2F1. As a result, G1-S-associated DNA and mRNA synthesis is inhibited, growth uncoupled from differentiation, and maturation enabled to proceed. Where this function of the tumor suppressor proteins is impaired, the capacity for differentiation is lost, which leads to the sustained proliferation that is characteristic of the cancer cell.
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PMID:Tumor suppressor proteins as regulators of cell differentiation. 976 53

We have identified specific iron (Fe) chelators of the pyridoxal isonicotinoyl hydrazone (PIH) class that are far more effective ligands than desferrioxamine (DFO; Richardson et al, Blood 86:4295, 1995; Richardson and Milnes, Blood 89:3025, 1997). In the present study, we have compared the effect of DFO and one of the most active chelators (2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone; 311) on molecular targets involved in proliferation. This was performed to further understand the mechanisms involved in the antitumor activity of Fe chelators. Ligand 311 was far more active than DFO at increasing Fe release from SK-N-MC neuroepithelioma and BE-2 neuroblastoma cells and preventing Fe uptake from transferrin. Like DFO, 311 increased the RNA-binding activity of the iron-regulatory proteins (IRPs). However, despite the far greater Fe chelation efficacy of 311 compared with DFO, a similar increase in IRP-RNA binding activity occurred after 2 to 4 hours of incubation with either chelator, and the binding activity was not inhibited by cycloheximide. These results suggest that, irrespective of the Fe chelation efficacy of a ligand, an increase IRP-RNA binding activity occurred via a time-dependent step that did not require protein synthesis. Further studies examined the effect of 311 and DFO on the expression of p53-transactivated genes that are crucial for cell cycle control and DNA repair, namely WAF1, GADD45, and mdm-2. Incubation of 3 different cell lines with DFO or 311 caused a pronounced concentration- and time-dependent increase in the expression of WAF1 and GADD45 mRNA, but not mdm-2 mRNA. In accordance with the distinct differences in Fe chelation efficacy and antiproliferative activity of DFO and 311, much higher concentrations of DFO (150 micromol/L) than 311 (2.5 to 5 micromol/L) were required to markedly increase GADD45 and WAF1 mRNA levels. The increase in GADD45 and WAF1 mRNA expression was seen only after 20 hours of incubation with the chelators and was reversible after removal of the ligands. In contrast to the chelators, the Fe(III) complexes of DFO and 311 had no effect on increasing GADD45 and WAF1 mRNA levels, suggesting that Fe chelation was required. Finally, the increase in GADD45 and WAF1 mRNAs appeared to occur by a p53-independent pathway in SK-N-MC and K562 cells, because these cell lines lack functional p53. Our results suggest that GADD45 and WAF1 may play important roles in the cell cycle arrest observed after exposure to these chelators.
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PMID:The potential of iron chelators of the pyridoxal isonicotinoyl hydrazone class as effective antiproliferative agents III: the effect of the ligands on molecular targets involved in proliferation. 1039 46


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