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)

As a product of HSVI immediate-early gene, ICP22 is capable of interacting with various cellular transcriptive and regulatory molecules during viral infection so as to impact the normal cellular molecular mechanism. ICP22 expressed in transfected cells can push the cells' entering into S phase with binding to mdm-1 promoter region and impact its trans-transcription activating effect by P53. Consequently, the MDM-2 binds to P53, and the degradation effects by the ubiquitous pathway are decreased, improving indirectly the P53 levels in cells and making the cells progress into the S phase.
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PMID:Immediate-early gene product ICP22 inhibits the trans-transcription activating function of P53-mdm-2. 1765 67

The small-molecule inhibitor of murine double minute (MDM-2), Nutlin-3, induced variable apoptosis in primary acute myeloid leukemia (AML) blasts and promoted myeloid maturation of surviving cells, as demonstrated by analysis of CD11b and CD14 surface antigens and by morphologic examination. Although the best-characterized activity of Nutlin-3 is activation of the p53 pathway, Nutlin-3 induced maturation also in one AML sample characterized by p53 deletion, as well as in the p53(-/-) human myeloblastic HL-60 cell line. At the molecular level, the maturational activity of Nutlin-3 in HL-60 cells was accompanied by the induction of E2F1 transcription factor, and it was significantly counteracted by specific gene knockdown with small interfering RNA for E2F1. Moreover, Nutlin-3, as well as tumor necrosis factor (TNF) alpha, potentiated the maturational activity of recombinant TNF-related apoptosis-inducing ligand (TRAIL) in HL-60 cells. However, although TNF-alpha significantly counteracted the proapoptotic activity of TRAIL, Nutlin-3 did not interfere with the proapoptotic activity of TRAIL. Taken together, these data disclose a novel, potentially relevant therapeutic role for Nutlin-3 in the treatment of both p53 wild-type and p53(-/-) AML, possibly in association with recombinant TRAIL.
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PMID:The MDM-2 antagonist nutlin-3 promotes the maturation of acute myeloid leukemic blasts. 1797 5

Using the 1998 World Health Organization/International Society of Urological Pathology (WHO/ISUP) (2004 WHO), 1999 WHO/ISUP, and 1973 WHO classifications, we examined Ki67, BCL-2, TP53, and MDM-2 expressions in invasive and noninvasive urothelial neoplasias of the bladder of 72 patients, and compared the results regarding tumor category and grade with clinical outcome to determine the clinicopathological relevance of these classifications. Ki67 and TP53 expressions were correlated with tumor grades of the 1973 WHO classification, and they also distinguished "papillary urothelial neoplasm with low malignant potential" from other WHO/ISUP grades (p < 0.05). No difference was observed for Ki67 and TP53 expressions between the other WHO/ISUP grades (p > 0.05). Neither tumor grade nor tumor category correlated with MDM-2 or BCL-2 expressions (p > 0.05). WHO/ISUP classifications are obviously not superior to the 1973 WHO classification for grading urothelial neoplasia of the bladder. However, if the "papillary urothelial neoplasm with low malignant potential" is distinguished from grade 1 tumors of the 1973 WHO classification, more precise prognostic information may be obtained.
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PMID:Relationship of Ki67, TP53, MDM-2 and BCL-2 expressions with WHO 1973 and WHO/ISUP grades, tumor category and overall patient survival in urothelial tumors of the bladder. 1857 27

A cytokine-dependent (FL5.12), drug-sensitive, p53 wild type (WT) and a doxorubicin-resistant derivative line (FL/Doxo) were used to determine the mechanisms that could result in drug resistance of early hematopoietic precursor cells. Drug resistance was associated with decreased p53 induction after doxorubicin treatment, which was due to a higher level of proteasomal degradation of p53. Dominant-negative (DN) p53 genes increased the resistance to chemotherapeutic drugs, MDM-2 and MEK inhibitors, further substantiating the role of p53 in therapeutic sensitivity. The involvement of signal transduction and apoptotic pathways was examined, as drug resistance did not appear to be due to increased drug efflux. Drug-resistant FL/Doxo cells had higher levels of activated Raf/MEK/ERK signaling and decreased induction of apoptosis when cultured in the presence of doxorubicin than drug-sensitive FL5.12 cells. Introduction of DN MEK1 increased drug sensitivity, whereas constitutively active (CA) MEK1 or conditionally active BRAF augmented resistance, documenting the importance of the Raf/MEK/ERK pathway in drug resistance. MEK inhibitors synergized with chemotherapeutic drugs to reduce the IC(50). Thus the p53 and Raf/MEK/ERK pathways play key roles in drug sensitivity. Targeting these pathways may be effective in certain drug-resistant leukemias that are WT at p53.
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PMID:Involvement of p53 and Raf/MEK/ERK pathways in hematopoietic drug resistance. 1868 11

Expression of neuropilin-1 (NRP-1) has been shown in many cancer cells, but its molecular effect on tumorigenesis is largely unknown. In this report, we show that in aggressive types of renal cell carcinoma (RCC), NRP-1 is expressed at a high level. We show that after knockdown of NRP-1 by short hairpin RNA, RCC cells express significantly lower levels of MDM-2 and p63 proteins but higher levels of p53, and exhibit reduced migration and invasion. When implanted in mice, RCC cells with a reduced NRP-1 level have a statistically significant smaller tumor-forming ability than control cells. Also, NRP-1 knockdown RCC cells exhibit a more differentiated phenotype, as evidenced by the expression of epithelial-specific and kidney-specific cadherins, and the inhibition of sonic hedgehog expression participated in this effect. Inhibition of sonic hedgehog expression can be reversed by DeltaNp63alpha overexpression. Our study reveals that NRP-1 helps maintain an undifferentiated phenotype in cancer cells.
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PMID:Neuropilin-1 upholds dedifferentiation and propagation phenotypes of renal cell carcinoma cells by activating Akt and sonic hedgehog axes. 1897 7

To determine whether adenovirus-mediated wild-type p53 transfer after radiotherapy could radiosensitize non-small-cell lung cancer (NSCLC) cells to subclinical-dose carbon-ion beam (C-beam), H1299 cells were exposed to a C-beam or gamma-ray and then infected with 5 MOI of AdCMV-p53 or GFP (C-beam or gamma-ray with p53 or GFP). Cell cycle was detected by flow cytometric analysis. The apoptosis was examined by a fluorescent microscope with DAPI staining. DNA fragmentation was monitored by the TUNEL assay. P53 mRNA was detected by reverse-transcriptase polymerase chain reaction. The expression of p53, MDM(2), and p21 was monitored by Western blot. Survival fractions were determined by colony-forming assay. The percentages of G(1)-phase cells in C-beam with p53 increased by 8.2%-16.0%, 5.2%-7.0%, and 5.8%-18.9%, respectively, compared with C-beam only, gamma-ray with p53, or p53 only. The accumulation of G(2)-phase cells in C-beam with p53 increased by 5.7%-8.9% and 8.8%-14.8%, compared with those in gamma-ray with p53 or p53 only, respectively. The percentage of apoptosis for C-beam with p53 increased by 7.4%-19.1%, 5.8%-11.7%, and 5.2 %-19.2%, respectively, compared with C-beam only, gamma-ray with p53, or p53 only. The level of p53 mRNA in C-beam with p53 was significantly higher than that in p53 only. The expression level of p53 and p21 in C-beam with p53 was significantly higher than that in both C-beam with GFP and p53 only. The survival fractions for C-beam with p53 were significantly less than those for the other groups (p < 0.05). The data suggested that AdCMV-p53 transfer could more efficiently radiosensitize H1299 cells to subclinical-dose C-beam irradiation through the restoration of p53 function.
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PMID:Adenovirus-mediated wild-type p53 transfer radiosensitizes H1299 cells to subclinical-dose carbon-ion irradiation through the restoration of p53 function. 1924 48

MDM family proteins are crucial regulators of the oncosuppressor p53. Alterations of their gene status, mainly amplification events, have been frequently observed in human tumors.MDM4 is one of the two members of the MDM family. The human gene is located on chromosome 1 at q32-33 and codes for a protein of 490aa. In analogy to MDM2, besides the full-length mRNA several transcript variants of MDM4 have been identified. Almost all variants thus far described derive from a splicing process, both through canonical and aberrant splicing events. Some of these variants are expressed in normal tissues, others have been observed only in tumor samples. The presence of these variants may be considered a fine tuning of the function of the full-length protein, especially in normal cells. In tumor cells, some variants show oncogenic properties.This review summarizes all the different MDM4 splicing forms thus far described and their role in the regulation of the wild type protein function in normal and tumor cells. In addition, a description of the full-length protein structure with all known interacting proteins thus far identified and a comparison of the MDM4 variant structure with that of full-length protein are presented. Finally, a parallel between MDM4 and MDM2 variants is discussed.
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PMID:MDM4 (MDMX) and its Transcript Variants. 1972 10

Stable cell lines obtained by spontaneous immortalization might represent early stages of malignant transformation and be useful experimental models for studies of mechanisms of cancer development. The FHC (fetal human cells) cell line has been established from normal fetal colonic mucosa. Detailed characterization of this cell line and mechanism of spontaneously acquired immortality have not been described yet. Therefore, we characterized the FHC cell line in terms of its tumorigenicity, cytogenetics, and TP53 gene mutation analysis. FHC cells displayed capability for anchorage-independent growth in semisolid media in vitro and formed solid tumors after transplantation into SCID (severe combined immunodeficiency) mice. This tumorigenic phenotype was associated with hypotriploidy and chromosome number ranging from 66 to 69. Results of comparative genetic hybridization arrays showed that most chromosomes included regions of copy number gains or losses. Region 8q23 approximately 8q24.3 (containing, e.g., MYC proto-oncogene) was present in more than 20 copies per nucleus. Moreover, we identified mutation of TP53 gene in codon 273; triplet CGT coding Arg was changed to CAG coding His. Expression of Pro codon 72 polymorphic variant of p53 was also detected. Mutation of TP53 gene was associated with abolished induction of p21(Waf1/Cip1) and MDM-2 proteins and resistance to apoptosis after genotoxic treatment. Because of their origin from normal fetal colon and their relative resistance to the induction of apoptosis, FHC cells can be considered a valuable experimental model for various studies.
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PMID:Fetal colon cell line FHC exhibits tumorigenic phenotype, complex karyotype, and TP53 gene mutation. 2019 43

The murine double minute protein-2 (MDM-2) oncogene is a determinant of embryogenesis, tumorigenesis, and cell cycle progression. The effects of MDM-2 on these processes depend, in part, on its ability to inactivate the p53 tumor suppressor gene. Our goal was to determine whether MDM-2 protein overexpressions or p53 gene mutations are a frequent event in poor outcome pediatric acute lymphoblastic leukemia (ALL). This work was conducted on 46 children with ALL (31 males and 15 females) with age range 2-18 years, 18 children with matched age and sex were enrolled in the study as a control group. The MDM-2 expression by flowcytometry and p53 gene status by PCR were determined in peripheral blood or bone marrow of ALL children (at initial diagnosis) and also of control group. The ALL children were treated by the modified BFM 76179 protocol of therapy, 29 patients (63%) achieved complete remission, while 17 patients (37%) were subsequently failed to achieve complete remission or relapsed within 6 months of achieving complete remission (CR). MDM-2 was significantly overexpressed in 15 ALL patients (32.6%), compared to that of healthy controls, 4 of them (4/15), were out of 29 cases of CR (13.8%), and the other 11 cases were out of 17 relapsed cases (64.7%). In contrast to overexpression of MDM-2, the mutation of p53 was detected in 6 (13%) out of 46 ALL patients at the initial time of diagnosis, 3 of them (10.3%) were out of 29 cases of CR and the other 3 cases (17.6%) were out of 17 of relapsed group, which is significantly higher than CR group (P < 0.05). In relapsed group, 2 patients out of 3 cases with p53 mutation were MDM-2 negative, also, all 3 cases of mutant P53 among patients in CR were negative MDM2. A positive correlation was found between the MDM-2 overexpression and initial WBCs count, blast cell counts in peripheral blood and presence of CNS blasts (p < 0.05, p < 0.05 and p < 0.05 respectively). These results indicate that MDM-2 is overexpressed in a significant number of childhood ALL, it is more frequent in relapsed cases and its frequency is not related to p53 status. Thus measuring of MDM-2 as a bad prognostic marker even in cases with non mutant P53 is very important. Moreover, MDM-2 may be a potential molecular target for production of new cancer therapy.
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PMID:Prevalence and prognostic significance of murine double minute protein-2 overexpression and P53 gene mutations in childhood acute lymphoblastic leukemia. 2030 73

The mussel Mytilus trossulus can develop a neoplasia of the haemolymph, which occurs with high frequency (up to 40%) in nature. Associated with this disease are pro-apoptotic tumor-suppressor protein p53 isoforms, which are highly conserved between molluscs and vertebrates. The vertebrate wildtype p53 protein is maintained at low levels by the MDM2 protein in non-stressed cells to prevent undesired apoptosis. Identification of a putative invertebrate MDM-like homolog suggests early evolution of this mechanism of p53 regulation. The M. trossulus MDM homolog consists of a conserved NH(2)-terminal p53 binding domain, an acidic domain with highly conserved phosphorylation sites, and a highly conserved C-terminal RING-finger Zn-binding domain. Although BLAST queries predict this homologue to be more similar to vertebrate MDM2 than to MDM4, phylogenetic analysis suggests that it may be an ancestral form to both vertebrate MDM genes. Using yeast-two-hybrid assays and pull-down assays, we show that this molluscan MDM is able to bind to its p53 counterpart. We also show that MDM expression levels are directly correlated with p53 expression levels in healthy and in neoplastic haemocytes, but not with other p53 isoforms or with the proto-oncogene RAS. The combination of expression levels of five gene transcripts (p53, mdm, ras, Np63/73, and TAp63/73) is significantly correlated with late-stage haemic neoplasia in M. trossulus.
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PMID:An invertebrate mdm homolog interacts with p53 and is differentially expressed together with p53 and ras in neoplastic Mytilus trossulus haemocytes. 2041 99


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