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)

Dermal fibroblast strains cultured from affected members of a cancer-prone family with Li-Fraumeni syndrome (LFS) harbor a point mutation in one allele of the p53 tumor suppressor gene, resulting in loss of normal p53 function. In this study we have examined the ability of these p53-deficient strains to carry out the long-patch mode of excision repair, mediated by DNA polymerases delta and epsilon, after exposure to 60Co gamma radiation or far ultraviolet (UV) (chiefly 254 nm) light. Repair was monitored by incubation of the irradiated cultures in the presence of aphidicolin (apc) or 1-beta-D-arabinofuranosylcytosine (araC), each a specific inhibitor of long-patch repair, followed by measurement of drug-induced DNA strand breaks (reflecting non-ligated strand incision events) by alkaline sucrose velocity sedimentation. The LFS strains displayed deficient repair capacity in response to both gamma rays and UV light. The repair anomaly in UV-irradiated LFS cultures was manifested not only in the overall genome, but also in the transcriptionally active, preferentially repaired c-myc gene. Using autoradiography we also assessed unscheduled DNA synthesis (UDS) after UV irradiation and found this conventional measure of repair replication to be deficient in LFS strains. Moreover, both apc and araC decreased the level of UV-induced UDS by approximately 75% in normal cells, but each had only a marginal effect on LFS cells. We further demonstrated that the LFS strains are impaired in the recovery of both RNA and replicative DNA syntheses after UV treatment, two molecular anomalies of the DNA repair deficiency disorders xeroderma pigmentosum and Cockayne's syndrome. Together these results imply a critical role for wild-type p53 protein in DNA polymerase delta/epsilon-mediated excision repair, both the mechanism operating on the entire genome and that acting on expressed genes.
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PMID:Faulty DNA polymerase delta/epsilon-mediated excision repair in response to gamma radiation or ultraviolet light in p53-deficient fibroblast strains from affected members of a cancer-prone family with Li-Fraumeni syndrome. 862 79

We have attempted to establish a cell line from hair follicle dermal papillae microdissected from vibrissa of mice lacking p53 tumor suppressor gene. The hair follicle dermal papillae were obtained from three types of mice: null knockout, hetero-knockout and wild type litters. Continuous cell lines with short doubling time were obtained only from null knockout litter-mates. Dermal papilla cells from either the hetero-knockout or wild type mice did not multiply well, and died within three passages; provided, however, that in only three cases out of 40 primary dermal papilla implants from two hetero-knockout mice, the cell culture reached 29 passages with a much slower growth rate than the cell lines from the null-knockout mice. These data are in accordance with the notion that the loss of p53 function is closely related to perpetuation of cell cycles and or immortalization.
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PMID:Hair follicle dermal papilla cell lines from p53-knockout mice. 918 14

Twenty-one cases of vulvar Paget's disease were studied to assess possible prognostic indicators, including presence and depth of invasion, status of resection margins, tumor DNA cell content, and immunoreactivity for p53 and estrogen receptor proteins. Immunostaining for cytokeratin 7 (CK7), cytokeratin 20 (CK20), and gross cystic disease fluid protein-15 (GCDFP) were also performed. Patients were 45 to 82 years of age (mean, 66.9 years). Ten of 21 patients (47.6%) had invasive Paget's disease. Dermal invasion was < or = 1 mm in 7 of 10 cases and 2 mm, 3 mm, and 8 mm in the remaining three invasive tumors. Of the seven patients with minimally invasive Paget's disease (< or = 1 mm depth of invasion), five are alive with no evidence of disease, one died of an unrelated illness, and one is alive with biopsy-proven in situ Paget's disease, having refused operative treatment. Of the three patients with more than minimally invasive Paget's disease (> 1 mm), all had nodal metastases; one patient is alive with no evidence of disease, one died of undertermined causes, and one died of metastatic Paget's disease. The remaining 11 patients had Paget's disease confined to the epidermis and its adnexal structures. Seven of these patients were alive at last follow-up with no evidence of disease. Of the remaining four patients, one died of metastatic cervical cancer, one died of metastatic bladder cancer, one died of an unrelated illness, and one patient is alive with biopsy-proven in situ Paget's disease and awaiting operative treatment. Twenty of the 21 cases represented primary vulvar Paget's disease while one represented possible local spread from a cervical adenocarcinoma. The immunoprofiles were GCDFP+/CK7+/CK20- in 14 cases, GCDFP+/CK7+/CK20+ in 4 cases, and GCDFP-/CK7+/CK20- in 2 cases. All tumors were estrogen receptor-negative. Immunostaining for p53 was positive in 16 tumors and negative in four tumors. Seven of 12 (58%) patients with positive margins experienced local recurrence of Paget's disease, while the disease recurred in 1 of 4 patients with negative margins. Recurrence was observed in 3 of 5 patients with diploid tumors and in 4 of 10 patients with aneuploid tumors. Neither of these differences is statistically significant. This study supports the recognition of a category of minimally invasive vulvar Paget's disease that has a low risk of distant metastasis and death caused by disease. Status of surgical resection margins, tumor cell DNA ploidy, estrogen receptor expression, and p53 immunoreactivity are not predictive of local recurrence.
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PMID:Prognostic factors in Paget's disease of the vulva: a study of 21 cases. 1054 44

Neurofibromatosis type 1 (NF1) is a common autosomal dominant condition characterized by benign tumor (neurofibroma) growth and increased risk of malignancy. Dermal neurofibromas, arising from superficial nerves, are primarily of cosmetic significance, whereas plexiform neurofibromas, typically larger and associated with deeply placed nerves, extend into contiguous tissues and may cause serious functional impairment. Malignant peripheral nerve sheath tumors (MPNSTs) seem to arise from plexiform neurofibromas. The NF1 gene, on chromosome segment 17q11.2, encodes a protein that has tumor suppressor function. Loss of heterozygosity (LOH) for NF1 has been reported in some neurofibromas and NF1 malignancies, but plexiform tumors have been poorly represented. Also, the studies did not always employ the same markers, preventing simple comparison of the frequency and extent of LOH among different tumor types. Our chromosome 17 LOH analysis in a cohort of three tumor types was positive for NF1 allele loss in 2/15 (13%) dermal neurofibromas, 4/10 (40%) plexiform neurofibromas, and 3/5 (60%) MPNSTs. Although the region of loss varied, the p arm (including TP53) was lost only in malignant tumors. The losses in the plexiform tumors all included sequences distal to NF1. No subtle TP53 mutations were found in any tumors. This study also reports the identification of both NF1 "hits" in plexiform tumors, further supporting the tumor suppressor role of the NF1 gene in this tumor type.
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PMID:Chromosome 17 loss-of-heterozygosity studies in benign and malignant tumors in neurofibromatosis type 1. 1086 51

Human inflammatory breast carcinoma (IBC) is the most malignant type of breast cancer with an extremely poor prognosis. The dog is the unique animal species in which spontaneous inflammatory mammary carcinoma (IC) has been reported, although it is not well documented. The purpose of this study was to characterize histopathologically and immunohistochemically the canine IC, considering associated clinical features. Twenty-one dogs diagnosed with IC and with known clinical and necropsy data were included in the study. Tissue samples from necropsies underwent a histopathological review and an immunohistochemical study (Ki-67, estrogen receptor (ER), progesterone receptor (PR), and P53 tumor suppressor protein). The histological study revealed several types of carcinomas (solid, tubular, papillary, and adenosquamous) and three lipid-rich carcinomas. All tumors were ER negative. Two histological patterns of neoplastic dermal infiltration were observed: tubular/papillary and sarcomatous-like. Dermal sarcomatous-like infiltration was significantly related to previous treatments with progestagens (p = 0.006), primary type of IC (p = 0.03), extreme local pain (p = 0.02), reduced observation of emboli in dermal lymphatic vessels (p = 0.01), and increased expression of p53 (p = 0.001). PR expression was significantly higher in secondary post-surgical IC (p = 0.04). The absence of PR was related to the existence of pulmonary metastases at necropsy (p = 0.04). Canine primary IC is the most aggressive form of this disease with distinct histopathological and immunohistochemical characteristics. Progestins and endocrine-related mechanisms seem to be involved in canine IC development. Canine IC could serve as a spontaneous model for human IBC, particularly in studies concerned with new therapeutics approaches.
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PMID:Canine inflammatory mammary carcinoma: histopathology, immunohistochemistry and clinical implications of 21 cases. 1272 14

Systemic sclerosis (SSc) is a connective tissue disorder characterized by excessive deposition of extracellular matrix in the affected skin as well as various internal organs, vascular injury and immune abnormality; however, the etiology of SSc remains still unknown. We previously established an experimental mouse model for scleroderma by repeated local injections of bleomycin, a DNA damaging agent. In this study, we examined the induction of apoptosis and the expression of p53, p21 (Waf1/Cip1), and proliferating cell nuclear antigen (PCNA) in the lesional skin following bleomycin exposure in this model. Dermal sclerosis was induced by alternate day's injections of bleomycin for 4 weeks. TUNEL assay showed that apoptotic cells began to appear at 1 week after bleomycin exposure, and were prominently detected at 3-4 weeks. Immunohistochemical examination showed increased expression of p53 and p21 mainly in the infiltrating mononuclear cells at 2 weeks after bleomycin treatment. Bleomycin treatment markedly enhanced PCNA expression at 1-2 weeks, mainly in mesenchyme, as compared with control phosphate buffered saline treatment. Reverse transcriptase-polymerase chain reaction analysis showed that the expression of p53 and p21 mRNA was concurrently upregulated at 1-2 weeks after bleomycin treatment. Taken together, coordinate increased levels of p53 and p21 preceded the maximal induction of apoptosis and dermal sclerosis. Our findings suggest that apoptotic processes are involved in the pathophysiology of bleomycin-induced scleroderma, which may be mediated, in part, by the upregulation of p53 and p21.
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PMID:Increased expression of p53 and p21 (Waf1/Cip1) in the lesional skin of bleomycin-induced scleroderma. 1580 28

Dicyclohexylcarbodiimide is used in industry as a stabilizing agent, coupling agent, and condensing agent. Its widespread use during protein synthesis in the recombinant DNA industry and in the synthesis of polypeptides in the chemical and pharmaceutical industries provides an increasing potential for low-level human exposure. Dicyclohexylcarbodiimide was nominated for study by The National Cancer Institute as a key representative of the carbodiimide chemical class because of its acute toxicity and the absence of data on potential health effects. Male and female F344/N rats and B6C3F 1 mice were administered dicyclohexylcarbodiimide (greater than 98% pure) dermally for 3 or 13 weeks. Female Tg.AC hemizygous and p53 haploinsufficient mice were administered dicyclohexylcarbodiimide dermally for 20 or 27 weeks, respectively. Genetic toxicology studies were conducted in Salmonella typhimurium, male F344/N rat bone marrow cells, and B6C3F 1 mouse peripheral blood erythrocytes. 3-WEEK STUDY IN F344/N RATS Groups of five male and five female rats were dermally administered 0.3 mL ethanol containing 0, 0.6, 1.8, 5.1, 15, or 45 mg dicyclohexylcarbodiimide, 5 days per week for 3 weeks. All males and females in the 15 and 45 mg groups, four 5.1 mg males, and all 5.1 mg females died before the end of the study. Of the surviving groups, final mean body weights were similar to those of the vehicle controls, although the one surviving 5.1 mg male rat lost weight during the study. Histopathologic examination of rats dosed with 5.1 mg dicyclohexylcarbodiimide or less revealed treatment-related lesions of the skin at the site of application including epidermal hyperplasia, epidermal necrosis, or chronic active inflammation in the dermis. 3-WEEK STUDY IN B6C3F 1 MICE Groups of five male and five female mice were dermally administered 0.1 mL of ethanol containing 0, 0.2, 0.6, 1.7, 5, or 15 mg dicyclohexylcarbodiimide, 5 days per week for 3 weeks. One 0.6 mg female mouse and all mice in the 1.7, 5, and 15 mg groups died before the end of the study. Final mean body weights of the 0.6 mg groups were significantly less than those of the vehicle controls, and animals in these groups generally lost weight during the study. Histopathologic examination of mice dosed with 1.7 mg dicyclohexylcarbodiimide or less revealed treatment-related lesions of the skin at the site of application including epidermal hyperplasia, epidermal necrosis, and acute or chronic active dermal inflammation. 13-WEEK STUDY IN F344/N RATS Groups of 10 male and 10 female core study rats were dermally administered 0, 0.75, 1.5, 3, 6, or 12 mg dicyclohexylcarbodiimide/kg body weight in ethanol, 5 days per week for 13 weeks; groups of 10 male and 10 female clinical pathology study rats were administered the same doses for 22 days. All 12 mg/kg male and female core study rats died or were found moribund and sacrificed prior to day 45. Final mean body weight and body weight gain of 6 mg/kg males were significantly less than those of the vehicle controls. The predominant clinical pathology changes suggest a secondary, treatment-related inflammatory leukogram and minimal decreased erythron of chronic inflammation that would be consistent with necrosis and chronic active inflammation of the skin. Significantly increased incidences of skin lesions at the site of application included epidermal hyperplasia in 3 mg/kg or greater males and 1.5 mg/kg or greater females, chronic active inflammation in 6 and 12 mg/kg males and 1.5 mg/kg or greater females, and epidermal necrosis in 12 mg/kg males. The incidences and severities of epidermal hyperplasia increased in a dose-related manner in both sexes of rats 13-WEEK STUDY IN B6C3F 1 MICE Groups of 10 male and 10 female mice were dermally administered 0, 1.5, 3, 6, 12, or 24 mg dicyclohexylcarbodiimide/kg body weight in ethanol, 5 days per week for 13 weeks. All 24 mg/kg male and female mice died or were found moribund and sacrificed prior to day 16. Final mean body weights of 6 and 12 mg/kg males and mean body weight gains of 6 and 12 mg/kg males and females were significantly less than those of the vehicle controls. The predominant clinical pathology changes suggest a secondary, treatment-related inflammatory leukogram and minimal decreased erythron of chronic inflammation that would be consistent with necrosis and chronic active inflammation of the skin. Dermal administration of dicyclohexylcarbodiimide significantly decreased the weight of the epididymis in 6 and 12 mg/kg males and significantly decreased epididymal spermatozoal motility in 6 mg/kg males. Significantly increased incidences of skin lesions at the site of application included epidermal hyperplasia in all dosed groups except those administered 24 mg/kg, chronic active inflammation in all dosed groups except 1.5 mg/kg females, and epidermal necrosis in 24 mg/kg males and females. 20-WEEK STUDY IN FEMALE TG.AC HEMIZYGOUS MICE Groups of 10 female Tg.AC hemizygous mice were dermally administered 0, 0.75, 1.5, 3, 6, or 12 mg dicyclohexylcarbodiimide/kg body weight in ethanol, 5 days per week for up to 20 weeks. Due to the severity of skin lesions observed in 12 mg/kg animals, the application of dicyclohexylcarbodiimide was discontinued after eight dermal applications in this group. There were no deaths considered related to dicyclohexylcarbodiimide administration, although 13 animals died or were sacrificed moribund prior to the end of the study: three each from the vehicle control and 0.75 mg/kg groups, four from the 3 mg/kg group, two from the 6 mg/kg group, and one from the 12 mg/kg group. Overall, the survival was within the range known for the Tg.AC hemizygous mouse. Mean body weights of dosed groups of mice were similar to those of the vehicle controls. At the site of application, the incidences of squamous cell papilloma were increased in a dose-related manner. The incidences of chronic active inflammation of the dermis and epidermal hyperplasia were significantly increased in mice administered 3 or 6 mg/kg. 27-WEEK STUDY IN FEMALE p53 HAPLOINSUFFICIENT MICE Groups of 15 female mice were dermally administered 0, 0.75, 1.5, 3, 6, or 12 mg dicyclohexylcarbodiimide/kg body weight in ethanol, 5 days per week for up to 27 weeks. Dosing of the 6 and 12 mg/kg groups was discontinued after 11 and 8 days, respectively, because of the severity of skin lesions at the site of application. Twelve animals died or were sacrificed moribund prior to the end of the study: three from the 3 mg/kg group, one from the 6 mg/kg group, and eight from the 12 mg/kg group. Mean body weights of dosed groups of mice were similar to those of the vehicle controls. No neoplasms were attributed to administration of dicyclohexylcarbodiimide. At the site of application, the incidences of focal epidermal hyperplasia were significantly increased in 1.5, 3, and 12 mg/kg mice, the incidences of focal chronic active inflammation of the dermis were increased in groups administered 3 or 12 mg/kg, and the incidences of focal ulcer and focal chronic active inflammation of the subcutaneous tissue were increased in the 12 mg/kg group. GENETIC TOXICOLOGY Dicyclohexylcarbodiimide was not mutagenic in Salmonella typhimurium strains TA97, TA98, TA100, or TA1535, with or without rat or hamster liver S9 activation enzymes. In vivo, there was a small but significant increase in the frequency of micronucleated normochromatic erythrocytes in male and female B6C3F 1 mice after 13 weeks of dermal exposure to dicyclohexylcarbodiimide. Negative results were obtained, however, in an acute three-injection micronucleus study in bone marrow of male F344/N rats. CONCLUSIONS Under the conditions of this 27-week dermal study, there was no evidence of carcinogenic activity* of dicyclohexylcarbodiimide in female p53 haploinsufficient mice administered 0.75, 1.5, 3, 6, or 12 mg/kg in ethanol. Female Tg.AC hemizygous mice dermally dosed with dicyclohexylcarbodiimide for 20 weeks had significantly increased incidences of squamous cell papilloma of the skin at the site of application. Nonneoplastic lesions noted at the site of application included chronic active inflammation and epidermal hyperplasia in female p53 haploinsufficient mice and female Tg.AC hemizygous mice.
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PMID:NTP report on the toxicology studies of dicyclohexylcarbodiimide (CAS No. 538-75-0) in F344/N rats, B6C3F 1 mice, and genetically modified (FVB Tg.AC hemizygous) mice and carcinogenicity study of dicyclohexylcarbodiimide in genetically modified [B6.129-Trp53 tm1Brd (N5) haploinsufficient] mice (dermal studies). 1878 65

There has been considerable interest in the use of genetically modified mice for detecting potential environmental carcinogens. For this reason, the National Toxicology Program has been evaluating Tg.AC hemizygous and p53 haploinsufficient mice as models to detect potential carcinogens. It was reasoned that these mouse models might also prove more effective than standard rodent models in evaluating the numerous disinfection byproducts that are found in low concentrations in drinking water. Dichloroacetic acid (DCA) is one of the most frequently found disinfection byproducts and DCA has been consistently shown to cause hepatocellular tumors in rats and mice in standard rodent studies. Tg.AC hemizygous and p53 haploinsufficient mice were exposed in the drinking water to DCA for up to 41 weeks. In a second study Tg.AC mice were subjected to dermal DCA exposure for up to 39 weeks. Increased incidences and severity of cytoplasmic vacuolization of hepatocytes were seen in the p53 mice, but there was no evidence of carcinogenic activity at exposures of up to 2000 mg/l in the drinking water. Increased incidences and severity of cytoplasmic vacuolization of hepatocytes were seen in the drinking water study with Tg.AC mice and a modest non-dose-related increase in pulmonary adenomas was observed in males exposed to 1000 mg/l in the drinking water. Dermal exposure up to 500 mg/kg for 39 weeks resulted in increased dermal papillomas at the site of application in Tg.AC mice. No significant increase in papillomas under the same study conditions was seen in the 26-week study. For DCA under these study conditions, the p53 and Tg.AC mice appear less sensitive to hepatocarcinogenesis than standard rodent models. These results suggest caution for the use of Tg.AC and p53 mice to screen unknown chemicals in drinking water for potential carcinogenicity.
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PMID:Evaluation of dichloroacetic acid for carcinogenicity in genetically modified Tg.AC hemizygous and p53 haploinsufficient mice. 1897 89

We analyzed two unrelated male patients in whom neurofibromatosis type 1 (NF1) was not suspected until they presented with malignant peripheral nerve sheath tumours (MPNSTs) in their thirties and forties, respectively. Patient A presented with progressive peroneus paresis due to a rapidly growing MPNST in the thigh. MRI examination revealed multiple symmetrical spinal neurofibromas in this patient as well as in patient B who presented at the age of 42 with paraparesis and an MPNST at spinal level L4. Dermal features in both patients were strikingly mild, therefore both patients were considered belonging to the NF1-subform of spinal neurofibromatosis (SNF). The novel NF1 mutations identified, i.e. splice mutation, c.7675+1G > A, in patient A and two alterations, p.Cys1016Arg and p.2711delVal, located in trans in patient B support the notion that the phenotype of SNF may be related to mutations with possible residual functionality. The MPNSTs of both patients showed LOH affecting chromosome 17 including the NF1 locus. Furthermore, a truncating TP53 mutation was identified in the tumour of patient A. Both alterations are frequent findings in NF1-associated MPNSTs. To our knowledge these are the first MPNST patients with the clinical phenotype of SNF. The clinical course observed in these two patients suggests that nodular plexiform neurofibromas and spinal-nerve-root neurofibromas which may be asymptomatic for a long time and, hence, unrecognized in SNF patients bear the risk for malignant transformation.
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PMID:Two sporadic spinal neurofibromatosis patients with malignant peripheral nerve sheath tumour. 1966 63

Dicyclohexylcarbodiimide (DCC) and Diisopropylcarbodiimide (DIC) are two representative chemicals in the carbodiimide class of chemicals used in industry as stabilizing agents. There is a potential of dermal exposure to these agents in chemical, pharmaceutical and recombinant DNA industries. The National Toxicology Program conducted a number of animal studies to characterize toxicity and carcinogenicity of DIC and DCC. Dermal administration of DCC and DIC in F344/N rats and B6C3F1 mice for 90-days induced skin irritation at the site of application in a dose-dependent manner. Microscopically, dose-dependent increases in epidermal hyperplasia and chronic inflammation were observed. We further evaluated the effects of dermal exposure of DCC and DIC in p53 haploinsufficient and Tg.AC mouse models. Results revealed the skin as the primary target of DCC and DIC exposure as indicated by dose - dependent skin lesions (hyperplasia, inflammation and necrosis). DCC induced squamous cell papillomas in Tg.AC mice but did not induce any neoplastic lesions in p53 haploinsufficient mice. Dermal application of DIC did not induce any neoplastic lesions in Tg.AC mice and p53 haploinsufficient mice. Based on these studies, it was predicted that DIC would be negative and DCC positive for carcinogenic activity in the traditional two-year bioassay. In the subsequent studies, the carcinogenic potential of DIC only in F344 rats and B6C3F1 mice in a traditional 2-year chronic carcinogenicity bioassay was evaluated by the dermal route. Findings revealed the skin as the major target organ of toxicity in both sexes in rats and in male mice. There were no neoplastic lesions observed in rats or mice with the administration of DIC. In rats, there were clinical signs of toxicity in the highest dose-group which included ataxia, excitability, impaired gait, low muscle tone, abnormal breathing, lethargy, and seizures. This was accompanied by non-neoplastic lesions in the brain and lung only at the highest dose level. In conclusion, both DIC and DCC are dermal toxicants. DIC did not have any carcinogenic activity in transgenic mouse models or in the traditional NTP two-year carcinogenicity studies in F344 rats and B6C3F1 mice. DCC was positive in the Tg.AC mouse model and likely to be carcinogenic in the 2-year bioassay as well.
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PMID:Comparative dermal toxicity of dicyclohexylcarbodiimide and diisopropylcarbodiimide in rodents. 2206 Aug 20


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