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 following study was designed to investigate if mutations within the p53 gene are associated with radiation responsiveness or response to different cytotoxic drugs. Nine human lung cancer cell lines were examined (four SCLC and five NSCLC cell lines). cDNA-based sequencing of the entire p53 gene was performed. All cell lines were characterised with respect to drug-sensitivity towards eight cytotoxic drugs using the FMCA method and data from the clonogenic assay were studied to obtain information concerning radioresponsiveness. All the cell lines expressed mutations; six were missense mutations and three were deletions. A statistically significant increase in radiosensitivity was found for mutations in exon 7 (p = 0.019), compared with the other mutations localised within different exons of p53. Further statistical analyses using Fisher's two-tailed exact test confirmed that mutations in exon 7 were significantly associated with radiosensitivity, p = 0.047. No correlation concerning mutations in separate exons and response towards different chemotherapeutic agents could be found. Our results indicate that p53 mutations in exon 7 might be associated with increased radiation sensitivity in these human lung cancer cell lines, but our data should be interpreted with caution since several other explanations might exist regarding what determines the response towards radiation.
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PMID:p53 status and its in vitro relationship to radiosensitivity and chemosensitivity in lung cancer. 1282 Mar 72

Many cancer and immortal cells exhibit telomerase activity that stabilizes telomere lengths, possibly contributing to cell immortality and carcinogenesis. The aim of this study was to elucidate the clinicopathological relationship between telomerase activity and telomerase reverse transcriptase subunit (hTERT) status in non small cell lung cancer. hTERT status in non small cell lung cancer using telomeric repeat amplification protocol (TRAP) and RT-PCR assay, respectively. Telomerase activity and hTERT were detected in 85.7 and 80.3% of cancerous tissues, respectively. Telomerase activity does not correlate with clinicopathological variables. However, there was an association between p53-correlated expression and hTERT negative status. Lung cancer patients without telomerase activity survived for a significantly longer period than those with telomerase activity. In addition, hTERT was not associated with the prognosis. TERT expression did not correlate well with any clinical parameter. Reactivated telomerase activity may be a poor prognostic factor in NSCLCs.
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PMID:Loss of telomerase activity may be a potential favorable prognostic marker in lung carcinomas. 1287 79

Telomerase activity was examined by the telomeric repeat amplification protocol (TRAP) assay in 38 neuroendocrine (NE) lung tumours. A significantly (p = 0.001) different frequency of telomerase positivity was observed among different histological tumour types. Specifically, a positive TRAP signal was observed in 14 of 15 (93%) small cell lung cancers (SCLCs), 7 of 8 (87%) large-cell NE carcinomas (LCNECs), and only 1 of 15 (7%) typical carcinoid tumours. When telomerase activity was correlated with the gene product-based immunophenotypic profile of individual tumours, it was found that the absence of telomerase activity was associated with a lack of bcl-2, p53, and c-kit expression, and characterized by a low proliferation index consistent with the absence of cdk-4 expression and the presence of the cdk inhibitor Rb. Such a phenotype was appreciable in most of the carcinoid tumours. Conversely, telomerase-positive tumours generally showed an immunophenotype consistent with gene product alterations (including high expression of bcl-2, p53, and c-kit, and loss of Rb) and were characterized by a high proliferation index. These telomerase data support the previously reported evidence for two genetically unrelated groups of NE lung tumours (SCLC, and to some extent LCNEC, versus carcinoid tumours) that have distinct phenotypic profiles.
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PMID:Differential expression of telomerase activity in neuroendocrine lung tumours: correlation with gene product immunophenotyping. 1295 25

A rationally designed, conditional p53 and Rb allele-based and lung-targeted mouse model of human small cell lung cancer (SCLC) provides the cancer research community with a valid and important new tool to use in translational research against this deadly disease.
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PMID:A big step in the study of small cell lung cancer. 1452 49

Small cell lung cancer (SCLC) is a highly aggressive human tumor with a more than 95% mortality rate. Its ontogeny and molecular pathogenesis remains poorly understood. We established a mouse model for neuroendocrine (NE) lung tumors by conditional inactivation of Rb1 and Trp53 in mouse lung epithelial cells. Mice carrying conditional alleles for both Rb1 and Trp53 developed with high incidence aggressive lung tumors with striking morphologic and immunophenotypic similarities to SCLC. Most of these tumors, which we designate MSCLC (murine small cell lung carcinoma), diffusely spread through the lung and gave rise to extrapulmonary metastases. In our model, inactivation of both Rb1 and p53 was a prerequisite for the pathogenesis of SCLC.
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PMID:Induction of small cell lung cancer by somatic inactivation of both Trp53 and Rb1 in a conditional mouse model. 1452 52

Recent studies have demonstrated the possibility to detect genetic changes in plasma DNA of cancer patients. The goal of this study was to validate a panel of molecular markers for lung cancer detection in plasma DNA. Three markers, p53, FHIT and microsatellite alterations at loci on chromosome 3, were used to detect mutations in tumor and plasma DNA of 64 stage I-III non small cell lung cancer patients. p53 mutations were studied by direct sequencing of exons 5 through 8 in tumor DNA and by plaque hybridization assay and sequencing in plasma DNA. Allelic losses were evaluated by fluorescent PCR in tumor and plasma DNA. p53 genomic mutations were detected in 26 (40.6%) of 64 tumor DNA samples and the identical mutation was identified in plasma of 19 (73.1%) of them. Microsatellite alterations at FHIT and 3p loci were observed in 40 (62.5%) tumors and in 23 (35.9%) plasma samples. Of the 40 patients showing microsatellite alterations in tumors, 19 (47.5%) displayed the same change in plasma DNA. At least 1 of the 3 genetic markers (p53, FHIT and 3p) was altered in plasma of 51.6% of all patients and 60.7% of stage I patients. Moreover, genetic markers in plasma identified 29 of 45 (64.4%) of all stages and 15 of 22 (68.2%) of stage I patients whose tumors had an alteration. These results provide the proof of principle that plasma DNA alterations are tumor-specific in most cases and support blood testing as a noninvasive strategy for early detection.
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PMID:Detecting lung cancer in plasma with the use of multiple genetic markers. 1461 21

A small cell carcinoma of the extrahepatic bile duct in a 75-year-old Japanese man is reported. The patient suffered from obstructive jaundice, and percutaneous transhepatic cholangiography-drainage (PTCD) revealed a massive lesion in the lower common bile duct. Because it was diagnosed as a malignant tumor, pancreaticoduodenectomy was performed. A nodular infiltrating tumor measuring 4.5 x 3.0 x 2.0 cm was located in the intrapancreatic portion of the extrahepatic bile duct. Histologically, the tumor was composed of a dense proliferation of small atypical cells with a little region of high-grade dysplasia in the adjacent epithelium of the common bile duct. Tumor cells were immunoreactive to neuroendocrine markers such as chromogranin A, synaptophysin, CD56, and Leu7. Although carcinoma cells invaded into pancreas and duodenum, there were no histological findings that indicated the carcinoma arose from the mucosa of either the pancreatic duct or duodenum. These results indicated that the tumor was a small cell carcinoma derived from the epithelium of the extrahepatic bile duct; a rare neoplasm with only a few cases reported. A few neuroendocrine cells were recognized in the adjacent epithelium of the extrahepatic bile duct, suggesting that the tumor cells might be derived from them. Using immunohistochemical examination, no p53 abnormality was found. Tumor cells showed positive nuclear staining for p16, while negative for cyclin D1, suggesting that functional retinoblastoma protein (pRB) might be lost in the p16/pRB pathway, as in small cell lung cancer.
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PMID:Small cell carcinoma of the extrahepatic bile duct: case report and immunohistochemical analysis. 1462 56

Cis-diaminechloro-[2-(diethylamino) ethyl 4-amino-benzoate, N(4)]-chloride platinum (II) monohydrochloride monohydrate (DPR) is a new platinum triamine complex obtained from the synthesis of cisplatin and procaine. In this paper we analyzed, adopting a disease-oriented strategy, the tumour selectivity of this compound, its ability to induce apoptosis and its mechanism of interaction with DNA. The inhibition of cell proliferation was evaluated by the MTT assay using a panel of 51 tumour cell lines. Some of them were also evaluated for the induction of apoptosis by 4'-6-diamidine-2'-phenylindole (DAPI) staining, Western blot of p53 protein and agarose gel electrophoresis of ladder DNA. Finally, interstand cross-links (ISCL) were evaluated by ethidium bromide fluorescence technique. When evaluated by the MTT assay, DPR showed a high selective activity for neuroblastoma, small cell lung cancer (SCLC), ovarian cancer and leukemia cell lines. The comparison of mean graphs of DPR and cisplatin suggested that our compound possesses a mechanism of action similar to that, at least in part, of its parent compound. Moreover, DPR showed itself to be a good trigger of programmed cell death, as demonstrated by DAPI staining, activation of p53 protein and agarose gel electrophoresis of ladder DNA. Finally, the study of the formation of ISCLs demonstrated that DPR, despite being a monofunctional platinum compound, is able to form bifunctional adducts through the release of procaine residue. Data presented here suggest that DPR is an antitumour agent able to trigger apoptosis, and that it is endowed with a peculiar mechanism(s) of action and a special selective activity against two tumours, namely neuroblastoma and SCLC, which are still characterized by a low incidence of long-term survivors.
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PMID:Inhibition of cell growth, induction of apoptosis and mechanism of action of the novel platinum compound cis-diaminechloro-[2-(diethylamino) ethyl 4-amino-benzoate, N(4)]-chloride platinum (II) monohydrochloride monohydrate. 1470 90

On the basis of data of the Human Genome Project, it was embraced the newest information about the gene content of the human genome, the disease genes, the parasitic DNA, the single nucleotide polymorphisms, the repeat sequences, the cytoskeletons, the regulation of cell proliferation, and their medical consequences. The applicability of the acquaintance with the human genome in pathology is presented with a few examples of our own. The significance of the single nucleotide polymorphisms in susceptibility to, or protection from, a host of disease is illustrated by the example of the allele variation of Apo-E gene. The copy number of the N-myc gene in neuroblastomas and HER2/neu gene in breast carcinomas was determined with quantitative PCR techniques. The monoclonally increased abnormal p53 protein expression was found in small cell lung cancer (in 90% frequency), in oro-pharyngeal carcinomas (82%), in esophageal squamous cell carcinomas (59%) in stomach cancer (33%), in colon carcinomas (27%) and in soft tissue sarcomas (13%). These data advert to the fact that the mutation of the p53 gene is much more frequent in those tumors in which the basic tissue is directly exposed to with the environmental carcinogens. It is now known, that near the repetitive sequences, gene rearrangement can more easily be evolve. Finally, we have determined the conditions of the accomplishment of the molecular pathological diagnosis: (1) It is applicable, when the classic morphology does not eventuate a conclusive result. (2) Well known and validated gene alterations are admissible to diagnostic purpose. (3) Only standard methods are applicable along with positive and negative controls. (4) The result has to correlate with the morphological picture, the immunohistochemical profile and the clinical data. (5) It is necessary to be able to appropriately interpret the molecular biological result, which is then incorporated in the pathological report. (6) The ethical, legal and social consequences must be considered.
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PMID:[Effect of learning about the human genome on the development of pathology]. 1497 56

PS-341 (bortezomib) represents a new class of therapeutics that targets the ubiquitin-proteasome pathway. It has broad-spectrum single-agent anticancer activity and can potentiate chemotherapy and radiation in preclinical models. Early phase clinical studies have shown tolerability and activity in multiple myeloma, lymphoma, prostate cancer, and lung cancers. By its mechanism of inhibiting protein degradation, PS-341 targets a wide range of pathways relevant to tumor progression and therapy resistance and can directly modulate expression of cyclins, p27(Kip1), p53, nuclear factor-kappaB, Bcl-2, and Bax. PS-341 is currently in phase I/II clinical development in both non-small cell lung cancer and small cell lung cancer. This article will review the preclinical and clinical experience with PS-341 as it relates to lung cancer.
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PMID:Proteasome inhibition with PS-341 (bortezomib) in lung cancer therapy. 1498 79


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