Early-Stage Lung adenocarcinoma MDM2 genomic heterogeneity predicts clinical outcome and response to targeted therapy
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE191171 | GEO | 2022/12/31
REPOSITORIES: GEO
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Project description:Amplification of the ubiquitin ligase MDM2 is a common mechanism of P53 inactivation across human tumors. Here we investigated the impact of supraphysiologic MDM2 expression on chromatin topology, gene expression and cellular phenotypes in liposarcoma tumors and models. We identified three independent gene regulatory circuits that predominate in aggressive, dedifferentiated tumors. RUNX and AP-1 family transcription factors bind a shared set of enhancers associated with mesenchymal lineage genes that underlie the developmental state of these tumors. P53 and MDM2 co-occupy enhancers and promoters associated with P53 pathways. When highly expressed, MDM2 also binds an additional set of P53-independent promoters that engage in multi-way physical interactions and regulate genes involved in cell division, RNA splicing, translation and stress responses. We find that liposarcoma cells with low to moderate MDM2 levels are sensitive to P53 inhibitors and their combination with pro-apoptotic agents, but that cells with very high-level MDM2 amplification and expression resist treatment. Hence, heterogeneity of MDM2 expression between and within tumors may compromise therapeutic regimens. In conclusion, we distinguished P53-dependent and P53-independent circuits in MDM2 copy number amplified tumors whose interplay has implications for targeted therapy.
2023-04-10 | GSE213300 | GEO
Project description:Immune checkpoint therapy has improved outcome of patients with advanced melanoma, however the tumor becomes refractory in a large number of patients. Therefore, novel combination therapies that enhance anti-melanoma immunity are highly desirable. We studied the impact of MDM2 (mouse double minute 2) inhibition, leading to p53 activation, on response to anti-PD-1 immunotherapy in melanoma. MDM2 treatment caused upregulation of MHC II and IL-15 in melanoma cells in a p53 dependent manner. Survival of melanoma bearing mice improved upon combining anti-PD1 and MDM2 inhibition in vivo. Lack of IL-15Rα in T cells abrogated the beneficial effect of the combined treatment. This gene expression study was performed to determine potential effects of MDM2 inhibition on genes in the melanoma microenvironment.
2024-08-22 | GSE184524 | GEO
Project description:Relapse after allo-HCT is a major cause of death of AML patients and results from immune evasion of AML blasts. Dysfunction of the p53 signaling pathway is frequent in AML and often caused by upregulation of the central p53 negative regulator Murine Double Minute 2 (MDM2). Besides its oncogenic effects p53 also regulates immune function and immune surveillance of solid cancer. We hypothesize that p53 also controls immune-related genes in AML cells and that p53 reactivation via MDM2-inhibition may enhance the immunogenicity of AML cells to allogeneic T cells.
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Project description:The identification of genetic alterations in sarcoma may give precious clues for the diagnosis. The detection of MDM2 amplification has an important impact since it may orientate towards a dedifferentiated liposarcoma (DDLPS) or more rarely towards an intimal sarcoma. Here we describe a poorly differentiated sarcoma initially diagnosed as a DDLPS, mainly on the basis of FISH analysis that detected MDM2 amplification. The patient was treated by adjuvant radiotherapy and, when the tumor recurred a few years later, MDM2 amplification was not observed anymore. We report the clinical, immunohistological, genomic and molecular description of the primary tumors and his recurrences.
2022-04-08 | GSE200434 | GEO
Project description:The model is based on publication:
Mathematical analysis of gefitinib resistance of lung adenocarcinoma caused by MET amplification
Abstract:
Gefitinib, one of the tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR), is effective for treating lung adenocarcinoma harboring EGFR mutation; but later, most cases acquire a resistance to gefitinib. One of the mechanisms conferring gefitinib resistance to lung adenocarcinoma is the amplification of the MET gene, which is observed in 5–22% of gefitinib-resistant tumors. A previous study suggested that MET amplification could cause gefitinib resistance by driving ErbB3-dependent activation of the PI3K pathway. In this study, we built a mathematical model of gefitinib resistance caused by MET amplification using lung adenocarcinoma HCC827-GR (gefitinib resistant) cells. The molecular reactions involved in gefitinib resistance consisted of dimerization and phosphorylation of three molecules, EGFR, ErbB3, and MET were described by a series of ordinary differential equations. To perform a computer simulation, we quantified each molecule on the cell surface using flow cytometry and estimated unknown parameters by dimensional analysis. Our simulation showed that the number of active ErbB3 molecules is around a hundred-fold smaller than that of active MET molecules. Limited contribution of ErbB3 in gefitinib resistance by MET amplification is also demonstrated using HCC827-GR cells in culture experiments. Our mathematical model provides a quantitative understanding of the molecular reactions underlying drug resistance.
2024-09-02 | BIOMD0000000827 | BioModels
Project description:The MDM2 oncoprotein is an essential component of the p53 pathway. Although MDM2 has been widely described as a major negative regulator of the p53 tumor suppressor, growing evidences support the notion that Mdm2 functions are also mediated through p53 independent mechanisms. We found that MDM2 is recruited on chromatin. By ChIP-Seq (using MDM2 antibody) of H1299 cells exhibiting MDM2 recruitment on chromatin, we identified at the whole genome level MDM2 binding sites. Both input and IPped-DNA were exhaustively sequenced and mapped on human genome
2016-06-09 | GSE64439 | GEO
Project description:Malignant rhabdoid tumors (MRT) are highly aggressive pediatric cancers that respond poorly to current therapies. We screened several MRT cell lines each with large-scale RNAi, CRISPR-Cas9, and small-molecule libraries to identify potential drug targets specific for these cancers. We discovered MDM2 and MDM4, the canonical negative regulators of p53, as significant vulnerabilities. Using two compounds currently in clinical development, idasanutlin and ATSP-7041, we show that MRT cells are more sensitive than other p53 wild-type cancer cell lines to MDM2 and dual MDM2/4 inhibition in vitro. These compounds cause significant upregulation of the p53 pathway in MRT cells, and sensitivity is ablated by CRISPR-Cas9-mediated inactivation of TP53. We show that loss of SMARCB1, a subunit of the SWI/SNF (BAF) complex mutated in nearly all MRT, sensitizes cells to MDM2 and MDM2/4 inhibition by enhancing p53-mediated apoptosis. Both MDM2 and MDM2/4 inhibition slowed MRT xenograft growth in vivo, with a five-day idasanutlin pulse causing marked regression of all xenografts including durable complete responses in 50% of mice. Together, these studies identify a genetic connection between mutations in the SWI/SNF chromatin-remodeling complex and the tumor suppressor gene p53, and provide preclinical evidence to support the targeting of MDM2 and MDM4 in this often-fatal pediatric cancer.
2019-02-04 | GSE124508 | GEO
Project description:Although amplification/overexpression is the predominant mechanism for the oncogenic properties of MDM2, an increasing number of MDM2 somatic missense mutations were identified in cancer patients with the recent advances in sequencing technology. Here, we characterized an MDM2 cancer-associated mutant variant W329G identified from patient samples that contain a wild-type p53 gene. We found that the MDM2 W329G mutant was resistant to the inhibitory effect of ribosomal protein L11 (RPL11) on MDM2-mediated p53 ubiquitination and degradation, in line with its defect on RPL11 binding. Using isogenic U2OS cells with or without endogenous mdm2 W329G mutation, we demonstrated that the expression of classic p53 targets induced by ribosomal stress signals was reduced in mutant cells. RNA-seq analysis revealed that upon 5-FU treatment, the p53 response was significantly impaired. Also, the 5-FU-mediated repression of genes in cell cycle progression and DNA replication was diminished in W329G mutant-containing cells. Physiologically, U2OS W329G cells were more resistant to cell growth inhibition induced by ribosomal stress and exhibited higher glycolytic rates upon 5-FU treatment. Together, our data indicated that cancer-associated MDM2 W329G mutant attenuates ribosomal stress-mediated p53 responses to promote cell survival and glycolysis.
2024-05-13 | GSE267150 | GEO
Project description:CDK4 inhibitors have reached clinical approval for cancer therapy. In parallel, the p53 antagonist Mdm2 remains an attractive target for anti-cancer therapy, including numerous clinical studies. The genes encoding Mdm2 and CDK4 are frequently co-amplified in human malignancies, most notably in liposarcomas, suggesting their combined targeting for therapy. Here we show, however, that small compounds that inhibit Mdm2 and CDK4 antagonize each other rather than synergize in their cytotoxicity towards sarcoma cells. CDK4 inhibition attenuates the induction of p53-responsive genes upon Mdm2 inhibition, and similar results were obtained when depleting Mdm2 and/or CDK4 with siRNA. CDK4 inhibitors also interfered with p53 activity in response to DNA damage. CDK4 inhibition did not reduce p53 binding or histone acetylation to promoters, but rather attenuated the subsequent recruitment of RNA polymerase II. The complexes of p53 and Mdm2, as well as CDK4 and Cyclin D1, physically associated with each other. Upon combined inhibition of Mdm2 and CDK4/6, the interaction of this complex was impaired. Thus, the CDK4-Cyclin D1 complex plays a key role in enabling the transcription of p53 target genes. Taken together, our results raise caution regarding the combination of CDK4 inhibitors with Mdm2 antagonists or conventional DNA-damaging chemotherapeutics in the clinics. Moreover, they suggest a hitherto unknown role for CDK4-cyclin D1 complex in sustaining p53 activity, possibly focusing p53-mediated transcription on actively proliferating cells.
2018-09-20 | GSE113369 | GEO
Project description:Mammalian SWI/SNF complexes are ATP-dependent chromatin remodelers composed of varying combinations of subunits that, together, fine-tune transcriptional regulation and genome integrity. SWI/SNF complex subunits have been identified as major targets of mutations in several tumor types suggesting a relevant role in tumorigenesis. However, there is a lack of comprehensive studies of the whole SWI/SNF complex in lung adenocarcinoma (LUAD). Here, we combined genomic, transcriptomic, and proteomic approaches to identify which SWI/SNF subunits are present in lung cells, as well as their mutational status, mRNA levels, and protein levels in LUAD. For these purposes, we combined data from LUAD primary tumors, normal lung and LUAD cell lines, and external LUAD data from The Cancer Genome Atlas. Importantly, we found that mutations in the SWI/SNF complex in LUAD not only present a high incidence but we also observed that only the mutational status of the SWI/SNF complex and not the mutations in any of the top ten LUAD driver genes is associated with poorer overall survival in LUAD patients. Furthermore, we showed that the expression of the SWI/SNF complex in LUAD suffers an overall repression that cannot be explained exclusively by genetic alterations. Based on our findings, we propose that SWI/SNF-mutant LUAD tumors should be considered as a distinct subgroup with practical applications in the prognosis and follow-up of LUAD patients.
2022-04-01 | PXD017397 | Pride