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)

We studied a rare polymorphism at exon 6 (CD 213) of the p53 gene in a healthy Turkish population (n = 26) and in Turks with different types of tumors such as malignant lymphoma (n = 12), osteosarcoma (n = 5), and nasopharyngeal sarcoma (n = 4). The polymorphic allele was found in only one of the malignant lymphoma patients (4.16%). Our data revealed that CD 213 (A-G) polymorphism is very rare in the Turkish population and there is no association with the tumors.
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PMID:p53 codon 213 (A-G) polymorphism in a Turkish population. 851 37

The transcription factor CCAAT/enhancer binding protein (C/EBP alpha) is expressed predominantly in differentiated tissues and is able to induce growth arrest and differentiation in preadipocytes. C/EBP alpha expression is high in non-dividing hepatocytes, but decreases during liver regeneration. These observations suggest that C/EBP alpha is inversely related to cell proliferation. To investigate the mechanism of growth inhibition by C/EBP alpha, the response of immortal human cells to cotransfection of a C/EBP alpha expression vector (CMV alpha) and a CMV beta-galactosidase expression vector was examined. Hep3B2, a hepatoma; Saos2, an osteosarcoma deficient for p53 and Rb; and 639, a fibroblast expressing SV40 T-antigen, were examined. Transiently transfected cells were stained for beta-gal activity to monitor their ability to undergo division. The ability of stable transformants to form colonies was also assessed for each cell line. Cells transfected with CMV alpha remained as non-dividing cells while control cells divided to form colonies. Mutations of the C/EBP alpha sequence demonstrated that only a small, previously uncharacterized activation domain was required for antimitotic activity. Our results suggest that C/EBP alpha may play a role in maintaining the quiescent state of hepatocytes and other cells. Furthermore, it appears that the effects of C/EBP alpha are not mediated through p53 or Rb and are not altered by T-antigen.
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PMID:Inhibition of cell proliferation by C/EBP alpha occurs in many cell types, does not require the presence of p53 or Rb, and is not affected by large T-antigen. 852 67

Li-Fraumeni syndrome(LFS) is an autosomal dominant disorder that predisposes individuals to multiple forms of cancer including breast cancer, soft tissue sarcoma, brain tumor, osteosarcoma, leukemia, and adrenocortical carcinoma. Recently, germ-line mutation of the p53 tumor suppressor gene has been implicated in this familial disorder. We report a case of a 25-year old woman who presented with bilateral breast cancer and uterine leiomyoma. Her mother had died of early-onset bilateral breast cancer. And her younger sister had breast carcinoma as well, which was identified at the age of 22, indicating her strong familial history. To test for the presence of the p53 germ-line mutation, we analyzed the genomic DNA from the peripheral blood of the proband and her sister by PCR-SSCP analysis of exon 5 through exon 8 of the p53 gene. As a result, a p53 mutation in exon 7 was detected in an allele, and it was shared with her sister as the same pattern. Sequencing analysis determined the altered nucleotide at codon 248(CGG > TGG) which is one of the most frequent mutation sites related to LFS. Therefore, this patient has the most consistent characteristic features of LFS phenotype and it is believed that this case is the first report of a family with Li-Fraumeni syndrome carrying the p53 germ-line mutation in Korea.
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PMID:The first documentation of Li-Fraumeni syndrome in Korea. 852 48

The Li-Fraumeni syndrome was initially recognized through clinical observations at the bed side, which was followed by epidemiological studies. Children suffering from rhabdomyosarcoma were shown to have two or more of six forms of cancer in their parents, grandparents and other relatives, indicating cancer family syndrome. This syndrome has been shown to involve tumor suppressor gene p53 mutations in the germ-line. The patients in the family most often have a proband with soft tissue sarcoma or osteosarcoma, and relatives with breast cancer, brain tumor, leukemia and adrenocortical cancer. Members of the family also appear to be at risk for developing second independent malignancies during their life span. Recommendations on predictive testing for germ line p53 mutations among cancer-prone individuals have been made by the subcommittees, which were sponsored by National Cancer Institute and the National Center for Human Genome Research.
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PMID:[Li-Fraumeni syndrome]. 853 47

A rapidly growing mandibular tumor occurred in a 17 month old female infant. Tumor outgrowth showing a periosteal reaction was radiographically seen on the lower surface (base) of the mandible. Under the biopsy diagnosis of osteosarcoma, high-dose chemotherapy with methotrexate was performed, resulting in little effect. The right hemimandibulectomy specimen disclosed intraosseous infiltrative growth of pleomorphic adenoma of salivary gland type, associated with chondroid stroma and reactive bone formation. The highly proliferative small-sized cells retained immunohistochemical features of myoepithelial cells, with positive reactivity of cytokeratin, vimentin, S-100 protein, alpha-smooth muscle actin, epithelial membrane antigen, CA15-3, type IV collagen, laminin and p53 protein. No heterotopia of the salivary gland was identified within the bone tissue. The tumor recurred 2 months later. Due to uncontrollable local growth, the patient died 8 months after operation. At autopsy, reactive ossification was closely associated with malignant myoepithelial proliferation. No distant metastasis was noted. This osteosarcoma-like tumor can be regarded as myoepithelial carcinoma in pleomorphic adenoma, originating from intramandibular heterotopic salivary gland tissue.
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PMID:Myoepithelial carcinoma in pleomorphic adenoma of salivary gland type, occurring in the mandible of an infant. 854 41

The expression of both epidermal growth factor (EGF) and platelet-derived growth factor (PDGF), and of their receptors (EGFR and PDGFR) was immunohistochemically examined in 37 cases of osteosarcoma. Furthermore, immunostaining for p53 protein and Ki-67 antigen by MIB-1 was carried out and compared with the above results. EGFR (81%) expressed more often than EGF (51%) and the expression of EGF and EGFR, and PDGF and PDGFR were recognized in 49% and 38%, respectively. In eleven cases (30%), the expression of both growth factors and their receptors was combined. Anaplastic osteosarcoma showed higher MIB-1 index than osteoblastic and fibroblastic subtypes (P < 0.05). High grade osteosarcomas (G3 and G4) revealed higher MIB-1 index compared with low grade tumors (G1 and G2). PDGF positive tumors (MIB-1 index: 20.0) showed significantly higher proliferation compared with PDGF negative tumors (MIB-1 index: 6.5) (P < 0.01). Five out of 37 cases (13.5%) showed positive immunoreaction for p53. There was no correlation of p53 status with MIB-1 index and the expression of growth factors or their receptors. Our results suggest that PDGF expression may be an important mediator of cell proliferation control, via an autocrine mechanism, in human osteosarcoma.
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PMID:Expression of growth factors and their receptors in human osteosarcomas. Immunohistochemical detection of epidermal growth factor, platelet-derived growth factor and their receptors: its correlation with proliferating activities and p53 expression. 854

Apoptin, a small protein derived from chicken anemia virus (CAV), induces apoptosis in human tumor cell lines regardless of whether these express p53 or not. We examined whether the small adenovirus 5 E1B protein of 21 kDa (E1B-21kD), also called E1B-19kD) and Bcl-2 could inhibit apoptin-induced apoptosis in human tumor cell lines and compared this with p53-induced apoptosis. E1B-21kD, but not Bcl-2 was found to inhibit apoptin-induced apoptosis in the osteosarcoma cell lines U2OS and Saos-2. However, neither expression of E1B-21kD nor of Bcl-2 resulted in inhibition of apoptin-induced apoptosis in Hep3B hepatoma cells and kidney rhabdoid tumor G401 cells. Both Bcl-2 and Ad5 E1B-21kD were able to inhibit p53-induced apoptosis in the human tumor cell lines Saos-2 and Hep3B. In Saos-2 and U2OS, but not in Hep3B and G401, expression of E1B-21kD leads to retention of apoptin in the cytoplasm, in that way preventing its nuclear function. These results indicate that proteins inhibiting the p53-induced apoptotic pathway do not block apoptin-induced apoptosis or do so only in a cell type-specific manner. The apoptin-induced apoptotic pathway is distinct from that induced by p53 and, therefore, apoptin is a potential antitumor agent.
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PMID:Differential sensitivity to Ad5 E1B-21kD and Bcl-2 proteins of apoptin-induced versus p53-induced apoptosis. 860 67

c-myb, a protooncogene prevalently expressed in the hematopoietic tissue, is a transcription factor that contains a DNA-binding domain and an acidic domain and is able to transactivate specific viral and cellular genes. In this report, we show that c-myb can stimulate apoptosis in both the murine promyelocytic 32D and the human osteosarcoma SAOS2 cell lines when coexpressed with p53. Apoptosis is accompanied by increased transactivation of the cell death-associated BAX gene. This effect is c-myb specific, because B-myb is not able to cooperate with p53 in the induction of BAX transcription and apoptosis. Immunoprecipitation studies and gel shift analysis indicate that c-myb does not directly interact with the BAX promoter or the p53 protein but, rather, cooperates through an indirect mechanism. Consistent with the existence of a functional link between c-myb and p53, we also observed that c-myb represses p53-induced activation of the WAF-1 promoter and induces proliferation of SAOS2 cells growth arrested by p53. These results might contribute to the elucidation of the mechanisms underlying p53-dependent pathways of oncogene-induced apoptosis and provide a further example of DNA-binding independent myb activity.
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PMID:Apoptotic response to oncogenic stimuli: cooperative and antagonistic interactions between c-myb and the growth suppressor p53. 861 38

Although the vast majority of eccrine spiradenomas behave in a benign fashion, 23 cases of malignant transformation have been reported to date. We describe a unique example of malignant eccrine spiradenoma that arose in the right breast of a 68-year-old woman. The quiescent mass, which was present for approximately 50 years, experienced sudden enlargement with erythematous changes of the overlying skin and nipple discharge. Microscopically, the tumor showed the typical features of an eccrine spiradenoma with areas of adenocarcinoma, squamous cell carcinoma, and sarcoma. The sarcomatous component consisted of rhabdomyosarcoma and osteosarcoma. The immunoperoxidase staining revealed p53 protein expression only in the carcinomatous and sarcomatous components. This suggests that accumulation of p53 protein may be an important event in the malignant transformation of spiradenomas. Because of its location and biphasic nature, this malignant eccrine spiradenoma should be distinguished from metaplastic breast carcinoma. To our knowledge, this represents the first carcinosarcomatous transformation of eccrine spiradenoma in the breast. This case led us to conclude that breast tissue, which often undergoes apocrine metaplasia and gives rise to apocrine neoplasms, is also capable of originating benign and malignant tumors with eccrine sweat duct phenotype.
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PMID:Carcinosarcoma arising in eccrine spiradenoma of the breast. Report of a case and review of the literature. 863 57

mac25, a retinoic acid-inducible gene that is expressed at high levels in senescent epithelial cells, was initially cloned as a gene that is differentially expressed in meningioma. Although the homology of its product with members of family of insulin-like growth factor-binding proteins was suggested, the product also exhibits strong homology to follistatin, an activin-binding protein. However, a domain corresponding to the carboxyl terminus of follistatin is not found in mac25. The carboxyl-terminally truncated form of follistatin, generated by alternative splicing, has stronger activin-binding activity than the complete form. This result suggests that mac25 might act as an activated follistatin. Clonal growth of a p53-deficient osteosarcoma cell line was strongly inhibited when the murine mac25 gene, as well as the p53 gene, was introduced. Resembling activins that belong to the transforming growth factor-beta (TGF-beta) superfamily, mac25 and p53 might associate with similar but distinct targets, namely cyclin-dependent kinase inhibitors. However, there is no evidence for compensation of p53 function by mac25 in the development of p53-deficient mice, as judged from the pattern of expression of mac25 in mice. mac25 might act as a tumor suppressor, modulating signaling of the TGF-beta family, as does alpha-inhibin.
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PMID:A follistatin-like gene, mac25, may act as a growth suppressor of osteosarcoma cells. 864 39


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