Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several protein fusion systems have been used in recent years to study protein-protein and DNA-protein interactions. Most of them use bacterially produced proteins which have several inherent disadvantages, notably, the absence of correct post-translational modifications and the frequent insolubility of recombinant proteins. We sought to develop a system to study proteins interacting with the nuclear phosphoprotein p53, which is believed to be a tumor suppressor. To prepare fusions of p53, we developed a convenient system that permits both in vivo and in vitro production and easy affinity purification of peptides and protein fragments as glutathione-transferase fusions. We placed the coding sequence of the Schistosoma japonica glutathione S-transferase (GST) under the control of the strong CMV/T7 promoter and SV40 splice and polyadenylation signals. An extensive polylinker (MCS) at the 3' end of the GST gene is preceded by the sequence encoding the cleavage site of the site-specific protease. We cloned the complete coding sequences of human wild-type p53, as well as p53 mutants representing all four mutational hotspots (codons 141, 175, 248, and 273), into our expression vector. In vitro transcription using the upstream T7 promoter and translation in reticulocyte lysates form an easy way to produce hybrid proteins; affinity purification on a glutathione-agarose column removes proteins that are present in reticulocyte lysates. We have also studied specific in vivo interactions of human p53 with the adenoviral 55-kDa E1B protein by transfecting expression constructs of GST-p53 fusions into human Ad5-transformed 293 cells.
 ...
PMID:Specific interaction between adenoviral 55-kDa E1B protein and in vivo produced p53 fusion proteins. 840 15

The purpose of the present study was to investigate the mechanisms involved in the antiproliferative and apoptotic effects of MCS-C2, a novel analog of the pyrrolo[2,3-d]pyrimidine nucleoside toyocamycin and sangivamycin, in human prostate cancer LNCaP cells. MCS-C2, a selective inhibitor of cyclin-dependent kinase, was found to inhibit cell growth in a time- and dose-dependent manner, and inhibit cell cycle progression by inducing the arrest of the G1 phase and apoptosis in LNCaP cells. When treated with 3 microM MCS-C2, inhibited proliferation associated with apoptotic induction was found in the LNCaP cells in a concentration and time-dependent manner, and nuclear DAPI staining revealed the typical nuclear features of apoptosis. Furthermore, MCS-C2 induced cell cycle arrest in the G1 phase through the upregulated phosphorylation of the p53 protein at Ser-15 and activation of its downstream target gene p21WAF1/CIP1. Accordingly, these results suggest that MCS-C2 inhibits the proliferation of LNCaP cells by way of G1-phase arrest and apoptosis in association with the regulation of multiple molecules in the cell cycle progression.
 ...
PMID:Cell cycle arrest and apoptotic induction in LNCaP cells by MCS-C2, novel cyclin-dependent kinase inhibitor, through p53/p21WAF1/CIP1 pathway. 1663 Jan 42

In the course of our screening for novel modulators on cell cycle progression and apoptosis as anticancer drug candidates, we generated an analogue of sangivamycin, MCS-C2, designated as 4-amino-6-bromo-7-cyclopentyl-7H-pyrrolo[2,3-d]pyrimidine-5-carboxamide. This study was aimed to evaluate the molecular mechanisms on cell cycle arrest and apoptotic induction of MCS-C2 in human lung cancer A549 cells. To investigate the effects of MCS-C2 on cell cycle progression in A549 cells, we measured DNA content of A549 cells treated with 5 microM of HY253 using flow cytometric analysis. The flow cytometric analysis revealed an appreciable G(2) phase arrest in A549 cells treated with 5 micronM of MCS-C2. This MCS-C2-induced G(2) phase arrest is associated with significant up-regulation of p53 and p21(Cip1) in A549 cells. Furthermore, TUNEL assay was used to examine apoptotic induction in A549 cells treated with 5 microM of MCS-C2 for 48 h. In addition, the effects of MCS-C2 on apoptosis-associated proteins in A549 cells were examined using Western blot analysis. The apoptotic induction in MCS-C2-treated A549 cells is associated with cytochrome c release from mitochondria which in turn resulted in the activation of caspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP). In conclusion, based on these results, we suggest that MCS-C2 may be a potent cancer chemotherapeutic candidate for use in treating human lung cancer cells via up-regulation and activation of p53.
 ...
PMID:Cell cycle arrest and cytochrome c-mediated apoptotic induction in human lung cancer A549 cells by MCS-C2, an analogue of sangivamycin. 2020 52

Apomorphine hydrochloride (APO) is known to be a dopamine receptor agonist, and has recently been found to be a novel drug for Alzheimer's disease (AD). We found that APO treatment ameliorated oxidative stress in an AD mouse model and specifically attenuated the hydrogen peroxide-induced p53-related apoptosis in the SH-SY5Y neuroblastoma cell line. To further understand the mechanism behind this action, we investigated the actions of APO on intracellular redox systems, such as the glutathione cycle and catalase. We studied the effects of specific inhibitors for glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (BCNU, MCS, and ATZ, respectively) on the effects of APO. Treatments with MCS or BCNU, but not ATZ, significantly attenuated the protective effects of APO. Interestingly, APO treatment elevated GPx activity, but did not increase the expression of the GPx1 protein. Although BCNU treatment attenuated APO effects, GR activity was not elevated by APO treatment. The same effects were observed in primary neuronal cultures. In addition, treatment with dopamine D1, D2, D3 and D4 receptor antagonists did not counteract the protective action of APO. Thus, APO may enhance GPx activity through dopamine receptor-independent pathways.
 ...
PMID:Activation of glutathione peroxidase and inhibition of p53-related apoptosis by apomorphine. 2179 52

Osteosarcoma (OS) is the most frequent primary malignant tumour of bone and metastases occur in 30% of cases, the 5-year survival rate is 25-30%. Although pre- and post-operative chemotherapy has improved prognosis in osteosarcoma (OS), high toxicity and natural and acquired drug-resistance are the first cause of treatment failure. The identification of new predictive and therapeutic biomarkers may increase drug sensitivity and better control localized and metastatic disease. By the evidence that CXCR4 receptor by binding its ligand CXCL12 activates downstream critical endpoints for tumour malignancy, we first studied human OS progression correlating CXCR4 expression in OS biopsy with patient clinical data. By Real-time PCR and immunoistochemistry we found that high levels of CXCR4 gene and protein expression significantly correlated with OS progression, emphasizing the role of CXCR4/CXCL12 axis in tumour prognosis. This was supported by univariate analyses that showed a higher probability of local and/or systemic relapse in OS patients with a high CXCR4 gene expression and a significant increase of metastasis risk associated with an increasing score of CXCR4 protein staining intensity. Secondarily, to study the role of CXCR4 as a target for new therapeutic strategies, we evaluated the response of OS cells to the fully human CXCR4 antibody, MDX1338. In the study we also included AMD3100, the most studied CXCR4 antagonist. In CXCR4-positive OS cells cultured in CXCL12-rich BM-MCS-CM (bone marrow-derived mesenchymal stem conditioned medium), a decrease of cell proliferation up to 30%-40% of control was seen after drug exposure. However, an increase of apoptosis was seen in p53-positive U2OS and 143B after CXCR4 inhibitor incubation, while no changes were seen in treated SAOS-2 cells which also present a different labeling profile. The role of p53 in apoptotic response to CXCR4 inhibitors was confirmed by p53 silencing in U2OS cell line. Our data suggest that the response to anti-CXCR4 agents could be influenced by the genetic background and labeling profile which induces a different cross-talk between tumour cells and environment. The delay in cell cycle progression associated with increased apoptosis could sensitize p53-positive cells to conventional therapy and in vivo preclinical experiments are on going with the aim to suggest new combined target therapies in human OS.
 ...
PMID:CXCR4 in human osteosarcoma malignant progression. The response of osteosarcoma cell lines to the fully human CXCR4 antibody MDX1338. 3119 11