MDM2-p53 Protein-protein Interaction Research Articles

New Insights into Chemoresistance Mediated by Mdm2 Inhibitors: The Benefits of Targeted Therapy over Common Cytostatics.

The inhibition of the Mdm2-p53 protein-protein interaction is a promising strategy for anticancer therapy. However, the problem of developing secondary chemoresistance in tumors treated with such drugs has not yet been sufficiently studied. In this work, we compared the properties of a drug-resistant cell line obtained during long-term cultivation in the presence of an Mdm2 inhibitor, Nutlin-3a, with a similarly obtained line insensitive to the cytostatic drug paclitaxel. We first confirmed the higher safety levels of Mdm2 inhibitors when compared with cytostatics in terms of the development of secondary chemoresistance. We showed that Nutlin-3a affects both the targeted p53-mediated cellular machinery and the universal ABC-mediated efflux mechanism. While both targeted and general defense mechanisms are activated by the Mdm2 inhibitor, it still increases the susceptibility of tumor cells to other drugs. The results obtained indicate that the risks of developing chemoresistance under the therapy with a targeted agent are fundamentally lower than during cytotoxic therapy.

MDM2 Antagonist Idasanutlin Reduces HDAC1/2 Abundance and Corepressor Partners but Not HDAC3.

Histone deacetylases 1-3 (HDAC1, HDAC2, and HDAC3) and their associated corepressor complexes play important roles in regulating chromatin structure and gene transcription. HDAC enzymes are also validated drug targets for oncology and offer promise toward new drugs for neurodegenerative diseases and cardiovascular diseases. We synthesized four novel heterobifunctional molecules designed to recruit the mouse double minute 2 homologue (MDM2) E3 ligase to degrade HDAC1-3 utilizing the MDM2 inhibitor idasanutlin, known as proteolysis targeting chimeras (PROTACs). Idasanutlin inhibits the MDM2-P53 protein-protein interaction and is in clinical trials. Although two MDM2-recruiting heterobifunctional molecules reduced HDAC1 and HDAC2 abundance with complete selectivity over HDAC3 and reduced HDAC1/2 corepressor components LSD1 and SIN3A, we were surprised to observe that idasanutlin alone was also capable of this effect. This finding suggests an association between the MDM2 E3 ligase and HDAC1/2 corepressor complexes, which could be important for designing future dual/bifunctional HDAC- and MDM2-targeting therapeutics, such as PROTACs.

One-pot three-component synthesis, in vitro anticancer activity and p53-MDM2 protein-protein interaction inhibition of novel spiro-oxindoline-based pyrazolo[3,4-b]pyridines

One-pot three-component synthesis, in vitro anticancer activity and p53-MDM2 protein-protein interaction inhibition of novel spiro-oxindoline-based pyrazolo[3,4-b]pyridines

Design, synthesis, and biological evaluation of furan-bearing pyrazolo[3,4-b]pyridines as novel inhibitors of CDK2 and P53-MDM2 protein-protein interaction.

The novel series of furan-bearing pyrazolo[3,4-b]pyridines were designed as cyclin-dependent kinase 2 (CDK2) inhibitors and as p53-murine double minute 2(MDM2) inhibitors. The newly synthesized compounds were screened for their antiproliferative activity towardhepatocellular carcinoma (HepG2) and breast cancer (MCF7) cell lines. The most active compounds on both cell lines were additionally evaluated for their in vitro CDK2inhibitory activity. Compounds 7b and 12f displayed enhanced activity (half-maximal inhibitory concentration[IC50 ] = 0.46 and 0.27 µM, respectively) in comparison to the standard roscovitine (IC50 = 1.41 ± 0.03 µM), in addition to, cell cycle arrest at S phase and G1/S transition phase in MCF7 cells treated with both compounds, respectively. Moreover, the most active spiro-oxindole derivative against MCF7 cell line, 16a, exhibited enhanced inhibitory activity against p53-MDM2 interaction in vitro (IC50 = 3.09 ± 0.12 µM) compared to nutlin, and increased the levels of both p53 and p21 by nearly fourfold in comparison to the negative control. Molecular docking studies demonstrated the plausible interaction patterns of the most potent derivatives 17b and 12f in the CDK2 binding pocket and the spiro-oxindole 16a with p53-MDM2 complex, respectively. Consequently, the new chemotypes 7b, 12f, and 16a can be presented as promising antitumor hits for further studies and optimization.

Explore drug-like space with deep generative models.

The process of design/discovery of drugs involves the identification and design of novel molecules that have the desired properties and bind well to a given disease-relevant target. One of the main challenges to effectively identify potential drug candidates is to explore the vast drug-like chemical space to find novel chemical structures with desired physicochemical properties and biological characteristics. Moreover, the chemical space of currently available molecular libraries is only a small fraction of the total possible drug-like chemical space. Deep molecular generative models have received much attention and provide an alternative approach to the design and discovery of molecules. To efficiently explore the drug-like space, we first constructed the drug-like dataset and then performed the generative design of drug-like molecules using a Conditional Randomized Transformer approach with the molecular access system (MACCS) fingerprint as a condition and compared it with previously published molecular generative models. The results show that the deep molecular generative model explores the wider drug-like chemical space. The generated drug-like molecules share the chemical space with known drugs, and the drug-like space captured by the combination of quantitative estimation of drug-likeness (QED) and quantitative estimate of protein-protein interaction targeting drug-likeness (QEPPI) can cover a larger drug-like space. Finally, we show the potential application of the model in design of inhibitors of MDM2-p53 protein-protein interaction. Our results demonstrate the potential application of deep molecular generative models for guided exploration in drug-like chemical space and molecular design.

Probing Alterations in MDM2 Catalytic Core Structure Effect of Garcinia Mangostana Derivatives: Insight from Molecular Dynamics Simulations.

The MDM2-p53 protein-protein interaction is a promising model for researchers to design, study, and discover new anticancer drugs. The design of therapeutically active compounds that can maintain or restore the binding of MDM2 to p53 has been found to limit the oncogenic activities of both. This led to the current development of a group of xanthone-core and cis-imidazoline analogs compounds, among which γ-Mangostin (GM), α-Mangostin (AM), and Nutlin exhibited their MDM2-p53 interaction inhibitory effects. Therefore, in this study, we seek to determine the mechanisms by which these compounds elicit MDM2-p53 interaction targeting. Unique to the binding of GM, AM, and Nutlin, from our findings, they share the same three active site residues Val76, Tyr50, and Gly41, which represent the top active side residues that contribute to high electrostatic energy. Consequently, the free binding energy contributed enormously to the binding of these compounds, which culminated in the high binding affinities of GM, AM, and Nutlin with high values. Furthermore, GM, AM, and Nutlin commonly interrupted the stable and compact conformation of MDM2 coupled with its active site, where Cα deviations were relatively high. We believe that our findings would assist in the design of more potent active anticancer drugs.

Discovery of MDM2-p53 and MDM4-p53 protein-protein interactions small molecule dual inhibitors

MDM2 and MDM4 are key negative regulators of p53, an important protein involved in several cell processes (e.g. cell cycle and apoptosis). Not surprisingly, the p53 tumor suppressor function is inactivated in tumors overexpressing these two proteins. Therefore, both MDM2 and MDM4 are considered important therapeutic targets for an effective reactivation of the p53 function. Herein, we present our studies on the development of spiropyrazoline oxindole small molecules able to inhibit MDM2/4-p53 protein-protein interactions (PPIs). Twenty-seven potential spiropyrazoline oxindole dual inhibitors were prepared based on in silico structural optimization studies of a hit compound with MDM2 and MDM4 proteins. The antiproliferative activity of the target compounds was evaluated in cancer cell lines harboring wild-type p53 and overexpressing MDM2 and/or MDM4. The most active compounds in SJSA-1 cells, 2q and 3b, induce cell death via apoptosis and control cell growth by targeting the G0/G1 cell cycle checkpoint in a concentration-dependent manner. The ability of the five most active spiropyrazoline oxindoles in dissociating p53 from MDM2 and MDM4 was analyzed by an immunoenzymatic assay. Three compounds inhibited MDM2/4-p53 PPIs with IC50 values in the nM range, while one compound inhibited more selectively the MDM2-p53 PPI over the MDM4-p53 PPI. Collectively, these results show: i) 3b may serve as a valuable lead for obtaining selective MDM2-p53 PPI inhibitors and more efficient anti-osteosarcoma agents; ii) 2a, 2q and 3f may serve as valuable leads for obtaining dual MDM2/4 inhibitors and more effective p53 activators.

Promising disruptors of p53-MDM2 dimerization from some medicinal plant phytochemicals: a molecular modeling study

Cancer is a major global health issue that has a high mortality rate. p53, which functions as a tumor suppressor, is critical in preventing tumor development by regulating the cell cycle and inducing apoptosis in damaged cells. However, the tumor suppressor function of p53 is effectively inhibited by its direct interaction with the hydrophobic cleft of MDM2 protein via multiple mechanisms As a result, restoring p53 activity by blocking the p53-MDM2 protein-protein interaction has been proposed as a compelling therapeutic strategy for cancer treatment. The use of molecular docking and phytochemical screening procedures are appraised to inhibit MDM2's hydrophobic cleft and disrupt the p53-MDM2 interaction. For this purpose, a library of 51 bioactive compounds from 10 medicinal plants was compiled and subjected to structure-based virtual screening. Out of these, only 3 compounds (Atalantoflavone, Cudraxanthone 1, and Ursolic acid) emerged as promising inhibitors of MDM2-p53 based on their binding affinities (-9.1 kcal/mol, −8.8 kcal/mol, and −8.8 kcal/mol respectively) when compared to the standard (-8.8 kcal/mol). Moreover, these compounds showed better pharmacokinetic and drug-like profiling than the standard inhibitor (Chromonotriazolopyrimidine 1). Finally, the 100 ns MD simulation analysis confirmed no significant perturbation in the conformational dynamics of the simulated binary complexes when compared to the standard. In particular, Ursolic acid was found to satisfy the molecular enumeration the most compared to the other inhibitors. Our overall molecular modeling finding shows why these compounds may emerge as potent arsenals for cancer therapeutics. Nonetheless, extensive experimental and clinical research is needed to augment their use in clinics. Communicated by Ramaswamy H. Sarma

The Discovery of Potential MDM2 Inhibitors: A Combination of Pharmacophore Modeling, Virtual Screening, Molecular Docking Studies, and in vitro/in vivo Biological Evaluation

Small-molecule inhibitors of MDM2 that block the MDM2-p53 protein-protein interaction have been considered as potential therapeutic agents for the treatment of cancer. Here, we identify five highly potent inhibitors of MDM2 (termed as WY 1-5) that display significant inhibitory effects on MDM2-p53 interaction by using a combined strategy of pharmacophore modeling, virtual screening, and molecular docking studies. Among them, WY-5 is the most active MDM2 inhibitor with an IC50 value of 14.1±2.8 nM. Moreover, WY-5 significantly up-regulate the protein level of p53 in SK-Hep-1 cells harboring wild-type p53. In vitro anticancer study reveals that WY-5 markedly inhibits the survival of SK-Hep-1 cells. In vivo anticancer study suggests that WY-5 significantly inhibits the growth of SK-Hep-1 cells-derived xenograft in nude mice, with no observable toxicity. Our results demonstrate that WY-5 may be a promising candidate for the treatment of cancer harboring wild-type p53.

Molecular hybridization design and synthesis of novel spirooxindole-based MDM2 inhibitors endowed with BCL2 signaling attenuation; a step towards the next generation p53 activators

Despite the achieved progress in developing efficient MDM2-p53 protein-protein interaction inhibitors (MDM2 inhibitors), the acquired resistance of tumor cells to such p53 activators posed an argument about the druggability of the pathway. Combination studies disclosed that concomitant inhibition of MDM2 and BCL2 functions can sensitize the tumor cells and synergistically induce apoptosis. Herein, we employed a rapid combinatorial approach to generate a novel series of hybrid spirooxindole-based MDM2 inhibitors (5a-s) endowed with BCL2 signaling attenuation. The adducts were designed to mimic the thematic features of the chemically stable potent spiro[3H-indole-3,2′-pyrrolidin]-2(1H)-ones MDM2 inhibitors while installing a pyrrole ring on the core via a carbonyl spacer inspired by the natural product marinopyrrole A that efficiently inhibits BCL2 family functions by various mechanisms. NCI 60 cell-line panel screening revealed their promising broad-spectrum antiproliferative activities. The NCI-selected derivatives were screened for cytotoxic activities against normal fibroblasts, MDA-MB 231, HepG-2, and Caco-2 cells via MTT assay, subjected to mechanistic apoptosis studies for assessment of p53, BCL2, p21, and caspase 3/7 status, then evaluated for potential MDM2 inhibition utilizing MST assay. The most balanced potent and safe derivatives; 5i and 5q were more active than 5-fluorouracil, exhibited low μmrange MDM2 binding (KD=1.32and 1.72 μm, respectively), induced apoptosis-dependent anticancer activities up to 50%, activated p53 by 47-63%, downregulated the BCL2 gene to 59.8%, and reduced its protein level (13.75%) in the treated cancer cells. Further downstream p53 signaling studies revealed > 2 folds p21 upregulation and > 3 folds caspase 3/7 activation. Docking simulations displayed that the active MDM2 inhibitors resided well into the p53 binding sites of MDM2, and shared key interactions with the co-crystalized inhibitor posed by the indolinone scaffold (5i, 5p, and 5q), the halogen substituents (5r), or the installed spiro ring (5s). Finally, in silico ADMET profiling predicted acceptable drug-like properties with full accordance to Lipinski’s, Veber’s, and Muegge’s bioavailability parameters for 5i and a single violation for 5q.

Establishment of drug-resistant cell lines under the treatment with chemicals acting through different mechanisms

The problem of chemoresistance development is an inescapable flipside of modern oncotherapy, in particular for сolorectal cancer patients. The search for or development of drugs effective against resistant tumors involves the use of model resistant cell lines in vitro. To obtain such lines, we reproduced the development of chemoresistance of human colon adenocarcinoma cells under the treatment with drugs of different mechanisms, a cytostatic (paclitaxel) and a targeted agent (Nutlin-3a, an inhibitor of p53-Mdm2 protein-protein interaction). In each case, we gradually increased the content of the substance in the medium, starting from effective concentrations that do not cause total cell death.When studying the lines resistant to the corresponding drug, we noted a reduced sensitivity to the drug of another mechanism of action. Analysis of the original and resistant lines showed that the cells use the universal efflux defense mechanism. The observed effect can be partially neutralized using inhibitors of the ABC transport proteins, including P-glycoprotein, known for its oncoprotective function. The role of the latter was confirmed by real-time RT-PCR and Western blotting.

Pharmacological activation of the p53 pathway by a new compound CYZ2017 exerts anti-tumor effects

Blockage of p53-MDM2 protein-protein interaction has long been a promising strategy of drug development for cancers with wild type p53. In this study, we report a new p53-MDM2 interaction inhibitor, CYZ2017, which could induce p53 nuclear translocation and possess p53-dependent anti-proliferation activity in a range of cancer cells. CYZ2017 treatment led to increase of p53 levels and induced the transactivation of its target genes p21. In addition, CYZ2017 induced G0/G1 cell cycle arrest and apoptosis in HCT116 cells. Besides, CYZ2017 suppressed tumor growth in a HCT116 xenograft model without visible toxicity. These results support that CYZ2017 might be a promising p53-MDM2 interaction inhibitor with good anti-tumor activity. Our finding provides some cues for further investigation of developing anti-tumor drugs based on the blockage of p53-MDM2 interaction.

Mdm2 inhibitors as a platform for the design of P-glycoprotein inhibitors

Chemoresistance is thought to be the cause of low treatment efficacy and mortality in more than 90% of patients with advanced cancer. The activation of drug efflux by P-glycoprotein is the key mechanism of resistance. All known P-gp inhibitors are used only in the combination therapy. We propose a new approach based on the multitarget rational design of drugs, which possess both the antitumor and efflux pump inhibitory activity. In this work, the principle possibility of combining the ability to inhibit P-gp and p53-Mdm2 protein-protein interaction in one structure is considered. The biological activity of a number of known and newly synthesized compounds was evaluated using cell lines with different p53 status. The possibility of using computer modeling for the search for P-glycoprotein inhibitors among Mdm2 inhibitors was analyzed; P-gp interaction site and binding modes of substrates and inhibitors were identified. The results obtained in cells that have the native balance of drug resistance and sensitivity showed the ability of the cells to both actively throw out xenobiotics and to lose this ability using P-gp inhibitors. The data obtained indicate that Mdm2 inhibitors are a promising platform for the development of multitarget drugs that can overcome tumor resistance by inhibiting the P-glycoprotein activity.

Small-molecule modulation of p53 protein-protein interactions.

Small-molecule modulation of protein-protein interactions (PPIs) is a very promising but also challenging area in drug discovery. The tumor suppressor protein p53 is one of the most frequently altered proteins in human cancers, making it an attractive target in oncology. 14-3-3 proteins have been shown to bind to and positively regulate p53 activity by protecting it from MDM2-dependent degradation or activating its DNA binding affinity. PPIs can be modulated by inhibiting or stabilizing specific interactions by small molecules. Whereas inhibition has been widely explored by the pharmaceutical industry and academia, the opposite strategy of stabilizing PPIs still remains relatively underexploited. This is rather interesting considering the number of natural compounds like rapamycin, forskolin and fusicoccin that exert their activity by stabilizing specific PPIs. In this review, we give an overview of 14-3-3 interactions with p53, explain isoform specific stabilization of the tumor suppressor protein, explore the approach of stabilizing the 14-3-3σ-p53 complex and summarize some promising small molecules inhibiting the p53-MDM2 protein-protein interaction.

Abstract A79: Inhibition of p53-MDM2 protein interaction reduces tumor growth in a mouse melanoma model

Abstract Tumor suppressor protein p53 is mutated in close to 50% of human tumors. Under steady state conditions, the two E3 ligases MDM2 and MDM4 interact with and inhibit the transcriptional activity of p53. Inhibition of p53-MDM2/4 interaction to reactivate p53 has therefore been considered a therapeutic strategy. In this study, we tested p53-MDM2 protein-protein interaction inhibition using the small molecule AMG 232, which is currently being tested in phase 1b/2a clinical trials. In vitro, AMG 232 induced a significant, p53-dependent growth arrest in the mouse melanoma cell line B16-F10. Using mass spectrometry-based proteomics, we identified differential protein expression patterns following AMG 232 treatment of B16-F10 melanoma cells. In vivo, the growth of B16-F10 melanoma cells implanted in WT C57BL/6 mice was significantly reduced by AMG 232 treatment. Our data demonstrate that AMG 232 induces a p53-dependent tumor growth arrest in an immunocompetent mouse model, and we are currently testing whether AMG232 can synergize with checkpoint immunotherapy. Citation Format: Katrine Ingelshed, Danai Lianoudaki, Dilraj Lama, Silke Sohn, Nicolas Fritz, Long Jiang, Fredrik Wermeling, Mikael Karlsson, David P. Lane, Saikiran K. Sedimbi. Inhibition of p53-MDM2 protein interaction reduces tumor growth in a mouse melanoma model [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A79.

α-Helix-Mimicking Sulfono-γ-AApeptide Inhibitors for p53-MDM2/MDMX Protein-Protein Interactions.

The use of peptidomimetic scaffolds is a promising strategy for the inhibition of protein–protein interactions (PPIs). Herein, we demonstrate that sulfono-γ-AApeptides can be rationally designed to mimic the p53 α-helix and inhibit p53–MDM2 PPIs. The best inhibitor, with Kd and IC50 values of 26 nM and 0.891 μM toward MDM2, respectively, is among the most potent unnatural peptidomimetic inhibitors disrupting the p53–MDM2/MDMX interaction. Using fluorescence polarization assays, circular dichroism, nuclear magnetic resonance spectroscopy, and computational simulations, we demonstrate that sulfono-γ-AApeptides adopt helical structures resembling p53 and competitively inhibit the p53–MDM2 interaction by binding to the hydrophobic cleft of MDM2. Intriguingly, the stapled sulfono-γ-AApeptides showed promising cellular activity by enhancing p53 transcriptional activity and inducing expression of MDM2 and p21. Moreover, sulfono-γ-AApeptides exhibited remarkable resistance to proteolysis, augmenting their biological potential. Our results suggest that sulfono-γ-AApeptides are a new class of unnatural helical foldamers that disrupt PPIs.

Discovery of Nonpeptide, Environmentally Sensitive Fluorescent Probes for Imaging p53-MDM2 Interactions in Living Cell Lines and Tissue Slice.

Based on structural optimization work, probes 9-11 with practical activity and selectivity in tissue as well as living cell lines are well designed and synthesized. All the probes showed potent inhibitory and acceptable cell toxicity compared with the commercially available p53-MDM2 inhibitor Nutlin-3, and can increase the protein expression level of p53 and MDM2 in the A549 cell line; in particular, probes 10 and 11 can increase the protein expression level of p53 better than Nutlin-3. Moreover, their application in imaging and detecting wild-type p53-MDM2 protein-protein interactions have been well demonstrated in at the cell and tissue levels. Overall, these environmentally sensitive fluorescent turn-on probes are affordable and rapid for imaging, which is expected for applications in target drug screening as well as in pathologic diagnosis.

РАЗРАБОТКА МЕТОДИКИ ВЫСОКОСОДЕРЖАТЕЛЬНОГО АНАЛИЗА ДЛЯ КОЛИЧЕСТВЕННОГО ОПРЕДЕЛЕНИЯ ПРОАПОПТОТИЧЕСКОЙ СПОСОБНОСТИ НИЗКОМОЛЕКУЛЯРНЫХ СОЕДИНЕНИЙ

The article presents the development of conditions for cell experiments using the Operetta CLS™ imaging system. The significance of high-content analysis parameters is substantiated. The optimal concentration and time parameters for the treatment of the cell culture of human colorectal carcinoma HCT116 by MDM2-p53 protein-protein interaction inhibitors were selected. The effect of the studied substances on cell growth was analyzed using Operetta CLS™.

Optimized Inhibitors of MDM2 via an Attempted Protein-Templated Reductive Amination.

Innovative and efficient hit‐identification techniques are required to accelerate drug discovery. Protein‐templated fragment ligations represent a promising strategy in early drug discovery, enabling the target to assemble and select its binders from a pool of building blocks. Development of new protein‐templated reactions to access a larger structural diversity and expansion of the variety of targets to demonstrate the scope of the technique are of prime interest for medicinal chemists. Herein, we present our attempts to use a protein‐templated reductive amination to target protein‐protein interactions (PPIs), a challenging class of drug targets. We address a flexible pocket, which is difficult to achieve by structure‐based drug design. After careful analysis we did not find one of the possible products in the kinetic target‐guided synthesis (KTGS) approach, however subsequent synthesis and biochemical evaluation of each library member demonstrated that all the obtained molecules inhibit MDM2. The most potent library member (K i=0.095 μm) identified is almost as active as Nutlin‐3, a potent inhibitor of the p53‐MDM2 PPI.

Abstract C060: Broad spectrum activity of the MDM2 inhibitor MI-773 in hematologic and solid cancer cell lines in-vitro and determination of predictive biomarkers

Abstract The Mouse Double Minute 2 (MDM2) proto-oncogene is a primary cellular inhibitor of p53 tumor suppressor protein. MDM2 encodes for a nuclear-localized E3 ubiquitin-protein ligase via direct interaction responsible for proteasomal degradation of p53. Its overexpression in TP53 wild type tumors leads to the loss of apoptotic function and cell survival. MDM2 inhibitors were envisioned to restore p53 activity in p53 wild type tumors, several are currently being evaluated in the clinic. MI-773 is a small molecule, that inhibits the p53-MDM2 protein-protein interaction. It has been evaluated in Phase I. We aimed to pursue characterization of MI-773’s anti-tumor activity by performing a large pharmacogenomic study to identify tumor candidates for such treatment. MI-773 was tested in vitro in a 2D monolayer assay in 274 human tumor cell lines (50 hematologic and 224 solid cancer cell lines) belonging to 36 tumor types. Drug sensitivity results in vitro were correlated with molecular data of the cell lines, including whole exome mutations, gene copy number variations and gene expression profiles, to study molecular determinants for a response. MI-773 showed a moderate anti-tumor potency (median IC50 13,5 µM, range 0.1 to up to30 µM) and pronounced selectivity was observed in several hematologic and solid cancer cell lines. Fifty tumor cell lines (18,5%) were 10 times more sensitive compared to the median IC50 of all cell lines. Among the solid cell lines, melanomas, kidney, stomach, breast and pleural mesotheliomas were the most sensitive tumor types, whereas ALL, AML, and multiple myelomas were the most sensitive hematological tumors. Confirmatory in vivo studies of MI-773 in the most sensitive tumors are planned. The Compare analysis of MI-773 with 44 targeted agents and 250 cytotoxic agents in 40 to 117 tumor cell lines showed the highest similarity with p53/MDM2 inhibitors Nutlin-3a and YH239-EE with Spearman correlation coefficients of 0,71 and 0,56, a clear indication that biological testing’s in cell line panels allows identification of the mechanism of action of novel compounds. As expected, TP53 mutation was the major determinant of tumor sensitivity to MI-773 (Wilcoxon test, adjusted p value= 2;28E-12). Sixty one out of 88 (69%) tumor cell lines wild type TP53 showed a high sensitivity to MI-773 whereas 141 out of 162 (87%) cell lines mutated for the gene were resistant. Transcriptome analysis revealed that the expression levels of 355 genes were significantly associated with sensitivity to MI-773 (LIMMA and Spearman test adjusted p values both p<0.05). MDM2, CDKN1A, SPATA18 and ZMAT3 were the strongest predictors positively associated with both TP53 integrity and sensitivity toward MI-773. Pathway analysis confirmed that overall the genes upregulated in tumor cell lines sensitive to MI-773 to be dominantly involved in negative regulation of mitotic cell cycle, regulation of cell cycle phase transition or signal transduction by p53 class mediator. The present study demonstrated that the MDM2 inhibitor MI-773 could be used in a broad range of hematological and solid tumor types, however, with the determination of TP53 as a prerequisite. MDM2 inhibitors should be evaluated in p53 wild type melanomas, mesotheliomas, kidney, stomach, and breast cancers as well as in ALL, AML, and multiple myelomas. Citation Format: Heinz-Herbert Fiebig, Gerhard Kelter, Hans R Hendriks, Hoor Al Hasani, Vincent Vuaroqueaux. Broad spectrum activity of the MDM2 inhibitor MI-773 in hematologic and solid cancer cell lines in-vitro and determination of predictive biomarkers [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C060. doi:10.1158/1535-7163.TARG-19-C060