scholarly journals Dual inhibition of MDMX and MDM2 as a therapeutic strategy in leukemia

2018 ◽  
Vol 10 (436) ◽  
pp. eaao3003 ◽  
Author(s):  
Luis A. Carvajal ◽  
Daniela Ben Neriah ◽  
Adrien Senecal ◽  
Lumie Benard ◽  
Victor Thiruthuvanathan ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Single Molecule ◽  
Cellular Proliferation ◽  
Wild Type ◽  
Suppressor Activity ◽  
Mouse Double Minute ◽  
Double Minute ◽  
Wild Type P53

The tumor suppressor p53 is often inactivated via its interaction with endogenous inhibitors mouse double minute 4 homolog (MDM4 or MDMX) or mouse double minute 2 homolog (MDM2), which are frequently overexpressed in patients with acute myeloid leukemia (AML) and other cancers. Pharmacological disruption of both of these interactions has long been sought after as an attractive strategy to fully restore p53-dependent tumor suppressor activity in cancers with wild-type p53. Selective targeting of this pathway has thus far been limited to MDM2-only small-molecule inhibitors, which lack affinity for MDMX. We demonstrate that dual MDMX/MDM2 inhibition with a stapled α-helical peptide (ALRN-6924), which has recently entered phase I clinical testing, produces marked antileukemic effects. ALRN-6924 robustly activates p53-dependent transcription at the single-cell and single-molecule levels and exhibits biochemical and molecular biological on-target activity in leukemia cells in vitro and in vivo. Dual MDMX/MDM2 inhibition by ALRN-6924 inhibits cellular proliferation by inducing cell cycle arrest and apoptosis in cell lines and primary AML patient cells, including leukemic stem cell–enriched populations, and disrupts functional clonogenic and serial replating capacity. Furthermore, ALRN-6924 markedly improves survival in AML xenograft models. Our study provides mechanistic insight to support further testing of ALRN-6924 as a therapeutic approach in AML and other cancers with wild-type p53.

Murine Double Minute 2 siRNA and wild-type p53 gene therapy interact positively with zinc on prostate tumours in vitro and in vivo

2014 ◽  
Vol 50 (6) ◽  
pp. 1184-1194 ◽  
Author(s):  
Junlian Gu ◽  
Bo Wang ◽  
Yanan Liu ◽  
Lingzhi Zhong ◽  
Yufeng Tang ◽  
...  
Keyword(s):  
Gene Therapy ◽  
P53 Gene ◽  
Wild Type ◽  
Double Minute ◽  
Murine Double Minute ◽  
Wild Type P53

scholarly journals Astrocytes derived from p53-deficient mice provide a multistep in vitro model for development of malignant gliomas.

1995 ◽  
Vol 15 (8) ◽  
pp. 4249-4259 ◽  
Author(s):  
A M Yahanda ◽  
J M Bruner ◽  
L A Donehower ◽  
R S Morrison
Keyword(s):  
Genomic Instability ◽  
Malignant Transformation ◽  
Nude Mice ◽  
Malignant Gliomas ◽  
Early Event ◽  
Wild Type ◽  
Early Passage ◽  
Wild Type P53

Loss or mutation of p53 is thought to be an early event in the malignant transformation of many human astrocytic tumors. To better understand the role of p53 in their growth and transformation, we developed a model employing cultured neonatal astrocytes derived from mice deficient in one (p53 +/-) or both (p53 -/-) p53 alleles, comparing them with wild-type (p53 +/+) cells. Studies of in vitro and in vivo growth and transformation were performed, and flow cytometry and karyotyping were used to correlate changes in growth with genomic instability. Early-passage (EP) p53 -/- astrocytes achieved higher saturation densities and had more rapid growth than EP p53 +/- and +/+ cells. The EP p53 -/- cells were not transformed, as they were unable to grow in serum-free medium or in nude mice. With continued passaging, p53 -/- cells exhibited a multistep progression to a transformed phenotype. Late-passage p53 -/- cells achieved saturation densities 50 times higher than those of p53 +/+ cells and formed large, well-vascularized tumors in nude mice. p53 +/- astrocytes exhibited early loss of the remaining wild-type p53 allele and then evolved in a manner phenotypically similar to p53 -/- astrocytes. In marked contrast, astrocytes retaining both wild-type p53 alleles never exhibited a transformed phenotype and usually senesced after 7 to 10 passages. Dramatic alterations in ploidy and karyotype occurred and were restricted to cells deficient in wild-type p53 following repeated passaging. The results of these studies suggest that loss of wild-type p53 function promotes genomic instability, accelerated growth, and malignant transformation in astrocytes.

scholarly journals Mortaparib, a novel dual inhibitor of mortalin and PARP1, is a potential drug candidate for ovarian and cervical cancers

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Jayarani F. Putri ◽  
Priyanshu Bhargava ◽  
Jaspreet Kaur Dhanjal ◽  
Tomoko Yaguchi ◽  
Durai Sundar ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Growth Arrest ◽  
Suppressor Activity ◽  
Dual Inhibitor ◽  
Tumor Suppressor Activity ◽  
And Migration

Abstract Background Mortalin is enriched in a large variety of cancers and has been shown to contribute to proliferation and migration of cancer cells in multiple ways. It has been shown to bind to p53 protein in cell cytoplasm and nucleus causing inactivation of its tumor suppressor activity in cancer cells. Several other activities of mortalin including mitochondrial biogenesis, ATP production, chaperoning, anti-apoptosis contribute to pro-proliferative and migration characteristics of cancer cells. Mortalin-compromised cancer cells have been shown to undergo apoptosis in in vitro and in vivo implying that it could be a potential target for cancer therapy. Methods We implemented a screening of a chemical library for compounds with potential to abrogate cancer cell specific mortalin-p53 interactions, and identified a new compound (named it as Mortaparib) that caused nuclear enrichment of p53 and shift in mortalin from perinuclear (typical of cancer cells) to pancytoplasmic (typical of normal cells). Biochemical and molecular assays were used to demonstrate the effect of Mortaparib on mortalin, p53 and PARP1 activities. Results Molecular homology search revealed that Mortaparib is a novel compound that showed strong cytotoxicity to ovarian, cervical and breast cancer cells. Bioinformatics analysis revealed that although Mortaparib could interact with mortalin, its binding with p53 interaction site was not stable. Instead, it caused transcriptional repression of mortalin leading to activation of p53 and growth arrest/apoptosis of cancer cells. By extensive computational and experimental analyses, we demonstrate that Mortaparib is a dual inhibitor of mortalin and PARP1. It targets mortalin, PARP1 and mortalin-PARP1 interactions leading to inactivation of PARP1 that triggers growth arrest/apoptosis signaling. Consistent with the role of mortalin and PARP1 in cancer cell migration, metastasis and angiogenesis, Mortaparib-treated cells showed inhibition of these phenotypes. In vivo tumor suppression assays showed that Mortaparib is a potent tumor suppressor small molecule and awaits clinical trials. Conclusion These findings report (i) the discovery of Mortaparib as a first dual inhibitor of mortalin and PARP1 (both frequently enriched in cancers), (ii) its molecular mechanism of action, and (iii) in vitro and in vivo tumor suppressor activity that emphasize its potential as an anticancer drug.

Wild Type p53 Gene Sensitizes Rat C6 Glioma Cells to HSV-TK/ACV Treatment In Vitro and In Vivo

2010 ◽  
Vol 16 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Qiang Huang ◽  
Zhibo Xia ◽  
Yongping You ◽  
Peiyu Pu
Keyword(s):  
Glioma Cells ◽  
P53 Gene ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Wild Type ◽  
Wild Type P53 ◽  
Rat C6 Glioma

scholarly journals A potent CBP/p300-Snail interaction inhibitor suppresses tumor growth and metastasis in wild-type p53-expressing cancer

2020 ◽  
Vol 6 (17) ◽  
pp. eaaw8500
Author(s):  
Hong-Mei Li ◽  
Yan-Ran Bi ◽  
Yang Li ◽  
Rong Fu ◽  
Wen-Cong Lv ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Epithelial Mesenchymal Transition ◽  
Therapeutic Effects ◽  
Creb Binding Protein ◽  
Wild Type ◽  
Mesenchymal Transition ◽  
Patients With Cancer ◽  
Wild Type P53

The zinc finger transcription factor Snail is aberrantly activated in many human cancers and associated with poor prognosis. Therefore, targeting Snail is expected to exert therapeutic benefit in patients with cancer. However, Snail has traditionally been considered “undruggable,” and no effective pharmacological inhibitors have been identified. Here, we found a small-molecule compound CYD19 that forms a high-affinity interaction with the evolutionarily conserved arginine-174 pocket of Snail protein. In aggressive cancer cells, CYD19 binds to Snail and thus disrupts Snail’s interaction with CREB-binding protein (CBP)/p300, which consequently impairs CBP/p300-mediated Snail acetylation and then promotes its degradation through the ubiquitin-proteasome pathway. Moreover, CYD19 restores Snail-dependent repression of wild-type p53, thus reducing tumor growth and survival in vitro and in vivo. In addition, CYD19 reverses Snail-mediated epithelial-mesenchymal transition (EMT) and impairs EMT-associated tumor invasion and metastasis. Our findings demonstrate that pharmacologically targeting Snail by CYD19 may exert potent therapeutic effects in patients with cancer.

scholarly journals Adenovirus mediated p53 tumour suppressor gene therapy for human gastric cancer cells in vitro and in vivo

Gut ◽  
1999 ◽  
Vol 44 (3) ◽  
pp. 366-371 ◽  
Author(s):  
M Ohashi ◽  
F Kanai ◽  
H Ueno ◽  
T Tanaka ◽  
K Tateishi ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Gene Therapy ◽  
P53 Gene ◽  
Human Gastric Cancer ◽  
Wild Type ◽  
Gastric Cancer Cells ◽  
Gastric Cancer Cell Lines ◽  
Wild Type P53

BACKGROUND/AIMSGastric cancer is one of the most prevalent forms of cancer in East Asia. Point mutation of the p53 gene has been reported in more than 60% of cases of gastric cancer and can lead to genetic instability and uncontrolled cell proliferation. The purpose of this investigation was to evaluate the potential of p53 gene therapy for gastric cancer.METHODSThe responses of human gastric cancer cell lines, MKN1, MKN7, MKN28, MKN45, and TMK-1, to recombinant adenoviruses encoding wild type p53 (AdCAp53) were analysed in vitro. The efficacy of the AdCAp53 treatment for MKN1 and MKN45 subcutaneous tumours in nude mice was assessed in vivo.RESULTSp53-specific growth inhibition was observed in vitro in two of four gastric cancer cell lines with mutated p53, but not in the wild type p53 cell line. The mechanism of the killing of gastric cancer cells by AdCAp53 was found, by flow cytometric analysis and detection of DNA fragmentation, to be apoptosis. In vivo studies showed that the growth of subcutaneous tumours of p53 mutant MKN1 cells was significantly inhibited by direct injection of AdCAp53, but no significant growth inhibition was detected in the growth of p53 wild type MKN45 tumours.CONCLUSIONSAdenovirus mediated reintroduction of wild type p53 is a potential clinical utility in gene therapy for gastric cancers.

Effects of Gamma Knife surgery on C6 glioma in combination with adenoviral p53 in vitro and in vivo

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 208-213 ◽  
Author(s):  
Desheng Xu ◽  
Qiang Jia ◽  
Yanhe Li ◽  
Chunsheng Kang ◽  
Peiyu Pu
Keyword(s):  
Glioma Cells ◽  
P53 Gene ◽  
Treated Group ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Survival Duration ◽  
Wild Type ◽  
Wild Type P53

ObjectThe authors sought to study the combined potential of wild-type p53 gene transfer and Gamma Knife surgery (GKS) for the treatment of glioblastomas multiforme. Modification of the radiation response in C6 glioma cells in vitro and in vivo by the wild-type p53 gene was investigated.MethodsStable expression of wild-type p53 in C6 cells was achieved by transduction of the cells with adenoviral p53. Two days later, some cells were treated with GKS. Forty-eight hours after irradiation, the comparative survival rate was assessed by monotetrazolium (MTT) assays. Treated and control C6 glioma cells (4 × 103 per well) were plated into a 96-well plate in octuplicate and tested every 24 hours. Meanwhile, immunohistopathological examination of proliferating cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate (TUNEL) assays were performed. The MTT assays indicated the p53, GKS, and combined treated cells proliferated at a significantly lower rate than those of the control group (p < 0.01, Days 2–6) and the positive fraction of PCNA in p53-treated group and GKS-treated group was 70.18 ± 3.61 and 50.71 ± 2.61, respectively, whereas the percentage in the combined group was 30.68 ± 1.49 (p < 0.01).Fifty-six male Sprague–Dawley rats were anesthetized and inoculated with 106 cultured C6 glioma cells into the cerebrum. Forty-eight hours after transduction with adenoviral p53, some rats underwent GKS. A margin dose of 15 Gy was delivered to the 50% isodose line. Two days later, six rats in each group were killed. Their brains were removed and paraffin-embedded section were prepared for immunohistopathological examination and TUNEL assays. The remaining rats were observed for the duration of the survival period. The survival curve indicated that a modest but significant enhancement of survival duration was seen in the p53-treated or GKS alone groups, whereas a more marked and highly significant enhancement of survival duration was achieved when these two treatment modalities were combined. When PCNA expression was downregulated, apoptotic cells become obvious after TUNEL staining.Conclusions The findings of this study suggest that p53-based gene therapy in combination with GKS may be superior to single-modality treatment of C6 glioma.

scholarly journals PRMT4-Mediated Arginine Methylation Negatively Regulates Retinoblastoma Tumor Suppressor Protein and Promotes E2F-1 Dissociation

2014 ◽  
Vol 35 (1) ◽  
pp. 238-248 ◽  
Author(s):  
Kevin Y. Kim ◽  
Don-Hong Wang ◽  
Mel Campbell ◽  
Steve B. Huerta ◽  
Bogdan Shevchenko ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Tumor Suppressor ◽  
Posttranslational Modifications ◽  
Transcriptional Activation ◽  
Cell Cycle Control ◽  
Arginine Methylation ◽  
Reporter System ◽  
Suppressor Activity

The retinoblastoma protein (pRb/p105) tumor suppressor plays a pivotal role in cell cycle regulation by blockage of the G1-to-S-phase transition. pRb tumor suppressor activity is governed by a variety of posttranslational modifications, most notably phosphorylation by cyclin-dependent kinase (Cdk) complexes. Here we report a novel regulation of pRb through protein arginine methyltransferase 4 (PRMT4)-mediated arginine methylation, which parallels phosphorylation. PRMT4 specifically methylates pRb at the pRb C-terminal domain (pRb Cterm) on arginine (R) residues R775, R787, and R798in vitroand R787in vivo. Arginine methylation is important for efficient pRb Ctermphosphorylation, as manifested by the reduced phosphorylation of a methylation-impaired mutant, pRb (R3K). A methylmimetic form of pRb, pRb (R3F), disrupts the formation of the E2F-1/DP1-pRb complex in cells as well as in an isolated system. Finally, studies using a Gal4–E2F-1 reporter system show that pRb (R3F) expression reduces the ability of pRb to repress E2F-1 transcriptional activation, while pRb (R3K) expression further represses E2F-1 transcriptional activation relative to that for cells expressing wild-type pRb. Together, our results suggest that arginine methylation negatively regulates the tumor suppressor function of pRb during cell cycle control, in part by creating a better substrate for Cdk complex phosphorylation and disrupting the interaction of pRb with E2F-1.

scholarly journals The isolation of an RNA aptamer targeting to p53 protein with single amino acid mutation

2015 ◽  
Vol 112 (32) ◽  
pp. 10002-10007 ◽  
Author(s):  
Liang Chen ◽  
Farooq Rashid ◽  
Abdullah Shah ◽  
Hassaan M. Awan ◽  
Mingming Wu ◽  
...  
Keyword(s):  
P53 Protein ◽  
P53 Gene ◽  
P53 Mutation ◽  
Single Amino Acid ◽  
Human Lung Cancer ◽  
Rna Aptamer ◽  
Wild Type ◽  
Wild Type P53

p53, known as a tumor suppressor, is a DNA binding protein that regulates cell cycle, activates DNA repair proteins, and triggers apoptosis in multicellular animals. More than 50% of human cancers contain a mutation or deletion of the p53 gene, and p53R175 is one of the hot spots of p53 mutation. Nucleic acid aptamers are short single-stranded oligonucleotides that are able to bind various targets, and they are typically isolated from an experimental procedure called systematic evolution of ligand exponential enrichment (SELEX). Using a previously unidentified strategy of contrast screening with SELEX, we have isolated an RNA aptamer targeting p53R175H. This RNA aptamer (p53R175H-APT) has a significantly stronger affinity to p53R175H than to the wild-type p53 in both in vitro and in vivo assays. p53R175H-APT decreased the growth rate, weakened the migration capability, and triggered apoptosis in human lung cancer cells harboring p53R175H. Further analysis actually indicated that p53R175H-APT might partially rescue or correct the p53R175H to function more like the wild-type p53. In situ injections of p53R175H-APT to the tumor xenografts confirmed the effects of this RNA aptamer on p53R175H mutation in mice.

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