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)

Sebaceous carcinoma (SC) is a rare malignancy, affecting mainly the periocular glands. To the best of the authors' knowledge, this is the first English-language report of parotid SC affecting children; two cases are presented. Immunohistochemical studies included 29 different antibodies (15 of these were cytokeratins, CKs). For each case, DNA ploidy status was determined using isolated nuclei stained with Feulgen and analysed using a DNA image cytometry system. Most of the tumour cells were positive for CKs AE1/AE3, 34B12, 5 and 7. The CK14 pattern depicted the monolayer of basal cells surrounding the islands of malignant tissue, while the more central sebaceous differentiated cells were negative. Epithelial membrane antigen was strongly positive in the well differentiated cells, while most of the basaloid peripheral cells were negative, and only a few cells were positive for carcinoembryonic antigen. beta catenin, E cadherin and C-erb B2 were expressed by most of the cells including the more differentiated sebaceous cells. Tumour cells were negative for muscle or myoepithelial markers, androgen, oestrogen and progesterone receptors. Both SCs were uniformly diploid, and showed low proliferative indices for p53, Ki-67 and Mcm-2, which is consistent with the good clinical course presented by these patients so far.
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PMID:Sebaceous carcinoma of the parotid gland in children: an immunohistochemical and ploidy study. 1839 14

Dedifferentiation of salivary gland neoplasms is a rare event, unlike bone and soft part sarcomas, which was first described by Stanley et al. in 1988. An additional case of dedifferentiated epithelial-myoepithelial carcinoma (EMC) is reported here. The patient was a 70-year-old Japanese man who requested examination of the rapid growth of a mass in the right parotid region, which he had first noticed 25 years previously. Clinical examination showed an ill-circumscribed, 6.8 x 4.7 x 7.0-cm lesion. Histologically, most parts of the lesion were high-grade carcinoma (HGC) with sheetlike and nestlike growth of markedly atypical cells and comedonecrosis, whereas the minor part consisted of typical EMC. The outer clear cells of EMC were positive for alpha-smooth muscle actin (ASMA), p63, cytokeratin (CK) 14, and vimentin, and the inner ductal cells of EMC were positive for CKs and epithelial membrane antigen. HGC was negative for ASMA, CK14, and vimentin, but diffusely positive for p53 protein and cyclin D1. The Ki-67 labeling index of EMC was 11.5%, whereas that of HGC was 67.1%. These findings and a review of literature indicate that HGC arose from preexisting EMC, and this phenomenon is the dedifferentiation of EMC. Dedifferentiated EMC is extremely rare.
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PMID:Dedifferentiated epithelial-myoepithelial carcinoma of the parotid gland: a rare case report of immunohistochemical analysis and review of the literature. 1841 80

Women with germ-line mutations of the BRCA1 tumor suppressor gene are highly susceptible to breast and ovarian cancer. The protein product of BRCA1 is involved in a broad spectrum of biological processes and interacts with many diverse proteins. One of these, BARD1, associates with BRCA1 to form a heterodimeric complex that is enzymatically active as an ubiquitin E3 ligase. Although the BRCA1/BARD1 heterodimer has been implicated in several aspects of BRCA1 function, its role in tumor suppression has not been evaluated. To address this question, we generated mouse strains carrying conditional alleles of either Bard1 or Brca1 and used Cre recombination to inactivate these genes in mammary epithelial cells. Significantly, the conditional Bard1- and Brca1-mutant mice developed breast carcinomas that are indistinguishable from each other (and from those of double conditional Bard1/Brca1-mutant animals) with respect to their frequency, latency, histopathology, and cytogenetic features. Reminiscent of the basal-like breast carcinomas seen in human BRCA1 mutation carriers, these tumors are "triple negative" for estrogen and progesterone receptor expression and HER2/neu amplification. They also express basal cytokeratins CK5 and CK14, have an elevated frequency of p53 lesions, and display high levels of chromosomal instability. The remarkable similarities between the mammary carcinomas of Bard1-, Brca1-, and Bard1/Brca1-mutant mice indicate that the tumor suppressor activities of both genes are mediated through the BRCA1/BARD1 heterodimer.
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PMID:The basal-like mammary carcinomas induced by Brca1 or Bard1 inactivation implicate the BRCA1/BARD1 heterodimer in tumor suppression. 1844 92

To investigate gene synergism in multistage skin carcinogenesis, the RU486-inducible cre/lox system was employed to ablate Pten function (K14.cre/Delta5Pten flx) in mouse epidermis expressing activated Fos (HK1.Fos). RU486-treated HK1.Fos/Delta5Pten flx mice exhibited hyperplasia, hyperkeratosis and tumours that progressed to highly differentiated keratoacanthomas, rather than to carcinomas, owing to re-expression of high p53 and p21 WAF levels. Despite elevated MAP kinase activity, cyclin D1 and cyclin E2 overexpression, and increased AKT activity that produced areas of highly proliferative papillomatous keratinocytes, increasing levels of GSK3beta inactivation induced a novel p53/p21 WAF expression profile, which subsequently halted proliferation and accelerated differentiation to give the hallmark keratosis of keratoacanthomas. A pivotal facet to this GSK3beta-triggered mechanism centred on increasing p53 expression in basal layer keratinocytes. This increase in expression reduced activated AKT expression and released inhibition of p21 WAF, which accelerated keratinocyte differentiation, as indicated by unique basal layer expression of differentiation-specific keratin K1 alongside premature filaggrin and loricrin expression. Thus, Fos synergism with Pten loss elicited a benign tumour context where GSK3beta-induced p53/p21 WAF expression continually switched AKT-associated proliferation into differentiation, preventing further progression. This putative compensatory mechanism required the critical availability of normal p53 and/or p21 WAF, otherwise deregulated Fos, Akt and Gsk3beta associate with malignant progression.
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PMID:Fos cooperation with PTEN loss elicits keratoacanthoma not carcinoma, owing to p53/p21 WAF-induced differentiation triggered by GSK3beta inactivation and reduced AKT activity. 1844 83

In order to illustrate the clinical and histological presentations of laryngeal atypical carcinoids and their potential course, we report six cases. We evaluated the factors predictive of local recurrence and metastatic diffusion. For each case, we noted the mitotic index, the quality of the resection, the limits of the tumor and the presence of necrosis. An immunohistochemical study was carried out with a series of antibodies (cytokeratins; D(2)40; CD31; MIB1; P53; P16; TTF1...). The clinical presentation we observed was quite similar to that reported in the literature. These tumors are CK7+, CK8+, CK19+, CK5-6-, CK14- and CK20-. P16 is constantly positive. Only the mitotic index and the lymphatic presence of embolus were correlated with the time course. The tumor is more aggressive when the mitotic index is high and an unfavorable course is observed when there are lymphatic emboli or when the Ki67 index is higher than 5%.
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PMID:[Atypical carcinoid of the arytenoid: report of six cases]. 1853 8

CCAAT/enhancer-binding protein-beta (C/EBPbeta) is a mediator of cell survival and tumorigenesis. When C/EBPbeta(-/-) mice are treated with carcinogens that produce oncogenic Ras mutations in keratinocytes, they respond with abnormally elevated keratinocyte apoptosis and a block in skin tumorigenesis. Although this aberrant carcinogen-induced apoptosis results from abnormal upregulation of p53, it is not known whether upregulated p53 results from oncogenic Ras and its ability to induce p19(Arf) and/or activate DNA-damage response pathways or from direct carcinogen-induced DNA damage. We report that p19(Arf) is dramatically elevated in C/EBPbeta(-/-) epidermis and that C/EBPbeta represses a p19(Arf) promoter reporter. To determine whether p19(Arf) is responsible for the proapoptotic phenotype in C/EBPbeta(-/-) mice, C/EBPbeta(-/-);p19(Arf-/-) mice were generated. C/EBPbeta(-/-);p19(Arf-/-) mice responded to carcinogen treatment with increased p53 and apoptosis, indicating p19(Arf) is not essential. To ascertain whether oncogenic Ras activation induces aberrant p53 and apoptosis in C/EBPbeta(-/-) epidermis, we generated K14-ER:Ras;C/EBPbeta(-/-) mice. Oncogenic Ras activation induced by 4-hydroxytamoxifen did not produce increased p53 or apoptosis. Finally, when C/EBPbeta(-/-) mice were treated with differing types of DNA-damaging agents, including alkylating chemotherapeutic agents, they displayed aberrant levels of p53 and apoptosis. These results indicate that C/EBPbeta represses p53 to promote cell survival downstream of DNA damage and suggest that inhibition of C/EBPbeta may be a target for cancer cotherapy to increase the efficacy of alkylating chemotherapeutic agents.
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PMID:C/EBPbeta represses p53 to promote cell survival downstream of DNA damage independent of oncogenic Ras and p19(Arf). 1863 78

The genome organization of the novel human papillomavirus type 108 (HPV108), isolated from a low-grade cervical lesion, deviates from those of other HPVs in lacking an E6 gene. The three related HPV types HPV103, HPV108, and HPV101 were isolated from cervicovaginal cells taken from normal genital mucosa (HPV103) and low-grade (HPV108) and high-grade cervical (HPV101) intraepithelial neoplasia (Z. Chen, M. Schiffman, R. Herrero, R. DeSalle, and R. D. Burk, Virology 360:447-453, 2007, and this report). Their unusual genome organization, against the background of considerable phylogenetic distance from the other HPV types usually associated with lesions of the genital tract, prompted us to investigate whether HPV108 E7 per se is sufficient to induce the above-mentioned clinical lesions. Expression of HPV108 E7 in organotypic keratinocyte cultures increases proliferation and apoptosis, focal nuclear polymorphism, and polychromasia. This is associated with irregular intra- and extracellular lipid accumulation and loss of the epithelial barrier. These alterations are linked to HPV108 E7 binding to pRb and inducing its decrease, an increase in PCNA expression, and BrdU incorporation, as well as increased p53 and p21(CIP1) protein levels. A delay in keratin K10 expression, increased expression of keratins K14 and K16, and loss of the corneal proteins involucrin and loricrin have also been noted. These modifications are suggestive of infection by a high-risk papillomavirus.
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PMID:E7 oncoprotein of novel human papillomavirus type 108 lacking the E6 gene induces dysplasia in organotypic keratinocyte cultures. 1915 27

Triple-negative breast carcinoma accounts for approximately 15% of all breast cancers. It is characterized by an aggressive clinical history, high rate of local relapse, and association with the basal epithelial-like subtype. Variations in breast cancer subtype and clinical outcome often exist across racial and ethnic lines. Therefore, the aim of this study was to compare the immunohistochemical and clinicopathologic characteristics of triple-negative breast carcinoma in women living in Vietnam with those from the United States. Invasive triple-negative breast carcinoma of patients from the 2 populations was characterized by tissue microarray for the expression of basal cytokeratins (CK5/6, CK7, CK14), luminal cytokeratins (CK8, CK18, CK19), and markers associated with the basal phenotype (cKit, epithelial growth factor receptor, P-cadherin, p53, and p63). Significant differences in expression between the 2 populations were not observed for the basal cytokeratins. However, epithelial growth factor receptor and P-cadherin, markers associated with the basal phenotype, were underexpressed in Vietnamese patients. Of the luminal cytokeratins, CK8 was overexpressed and CK18 was underexpressed in the Vietnamese women. Significant differences were also observed regarding the clinicopathologic characteristics. Triple-negative breast carcinoma in Vietnamese women was smaller and less likely to be grade III. In addition, it was more frequently of ductal histologic type and less often medullary or metaplastic. These differences in histology and marker expression suggest that triple-negative breast carcinoma has unique biological characteristics in women from Vietnam and the United States, and may follow a unique clinical course in each of the 2 populations.
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PMID:Triple-negative breast carcinoma in women from Vietnam and the United States: characterization of differential marker expression by tissue microarray. 1976 68

Recently, we presented evidence--based on the analysis of benign hyperproliferative lesions of the breast--for the presence of cells that express the stem cell marker cytokeratin (CK) 15 in combination with CK19, a protein widely expressed by mammary epithelial cells. Here we report the finding of a subset of breast carcinomas characterized by expression of CK15. CK15 expressing tumors constituted 5% (6 out of 120; 4 of ductal type and 2 of lobular type) of the high-risk breast carcinomas examined by gel-based proteomics and immunohistochemistry. Five out of the six CK15+ carcinomas were CK15+/CK19-. The remaining tumor was mainly composed of cells expressing both CK15 and CK19 (CK15+/CK19+), but it also contained invasive areas with cells expressing only one of these makers (CK15+/CK19- and CK15-/CK19+ cells). To address the relationship between putative luminal progenitor/amplified CK15+ cells and malignant disease, and to determine whether cells/lesions lose expression of CK15 as a result of tumour initiation and/or progression, we searched among our sample set for carcinomas in which invasive tumor areas co-existed with non-malignant cells and hyperproliferative and known pre-malignant lesions. Only one such tumour was found (T71), a CK15-/CK19+/p53+ carcinoma that contained p53 negative non-malignant epithelial cells exhibiting a variety of, CK15/CK19 cellular phenotypes (CK15+/CK19+; CK15+/CK19-; CK15-/CK19+; CK15-/CK19-), often associated with simple columnar cells. Single layers of epithelial cells exhibiting all four CK15/CK19 phenotypes were observed contiguous to areas of atypical ductal hyperplasia that contained p53 positive cells that lost CK15 expression (CK15-/CK19+) and had a very similar phenotype to those of the neighboring ductal carcinoma in situ (DCIS) and invasive cells. The undifferentiated CK15+/CK19+ cells, which had the phenotype CK15+/CK19+/CK14+/CK8+ and -/ER-/PgR-/AR-/CD44+ (weak)/CK17-/p63-/vimentin+/Ki67-/Bcl-2+ (weak)/GATA-3-/p53-, most likely correspond to lineage-restricted luminal progenitor cells able to generate the other more differentiated CK15/CK19 cellular phenotypes, thus giving rise to the daunting intratumour heterogeneity displayed by carcinoma T71. Cells with a very similar phenotype to the CK15+/CK19+ progenitor cells were observed in a juvenile fibroadenoma as well as in the large collecting ducts of the breast. The latter, however, expressed in addition CK14 and had a phenotype (CK15+/CK19+/CK14+/CK8+ (weak)/ER-/PgR-/AR-/CD44+ (weak)/CK17-/p63-/vimentin-/Ki67-/Bcl-2+/GATA-3-/p53-) that resembled that of the putative normal adult breast stem cells as inferred from published data. Further molecular characterization of these progenitor cells as well as unraveling of the signaling pathways that regulate their growth and differentiation may prove invaluable for developing novel therapeutic strategies that target cancer at an early stage.
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PMID:Identification of a subset of breast carcinomas characterized by expression of cytokeratin 15: relationship between CK15+ progenitor/amplified cells and pre-malignant lesions and invasive disease. 1938 6

Head and neck squamous cell carcinomas (HNSCC), the majority of which occur in the oral cavity, remain a significant cause of morbidity and mortality worldwide. A major limitation in HNSCC research has been the paucity of animal models to test the validity of current genetic paradigms of tumorigenesis and to explore the effectiveness of new treatment modalities and chemopreventive strategies. Here, we have developed an inducible oral-specific animal tumor model system, which consists in the expression of a tamoxifen-inducible Cre recombinase (CreER(tam)) under the control of the cytokeratin 14 (K14) promoter (K14-CreER(tam)) and mice in which the endogenous K-ras locus is targeted (LSL-K-ras(G12D)), thereby causing the expression of endogenous levels of oncogenic K-ras(G12D) following removal of a stop element. Surprisingly, whereas K14-CreER(tam) can also target the skin, K14-CreER(tam)/LSL-K-ras(G12D) mice developed papillomas exclusively in the oral mucosa within 1 month after tamoxifen treatment. These lesions were highly proliferative but never progressed to carcinoma. However, when crossed with p53 conditional knockout (p53(flox/flox)) mice, mice developed SCCs exclusively on the tongue as early as 2 weeks after tamoxifen induction, concomitant with a remarkable activation of the mammalian target of rapamycin (mTOR) signaling pathway. The availability of this ras and p53 two-hit animal model system recapitulating HNSCC progression may provide a suitable platform for exploring novel molecular targeted approaches for the treatment of this devastating disease. Indeed, we show here that mTOR inhibition by the use of rapamycin is sufficient to halt tumor progression in this genetically defined oral cancer model system, thereby prolonging animal survival.
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PMID:Rapamycin prevents early onset of tumorigenesis in an oral-specific K-ras and p53 two-hit carcinogenesis model. 1943 1


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