2-2-bis(hydroxymethyl)-1-azabicyclo(2-2-2-)octan-3-one and Neoplasms

p53 is the most mutated protein in cancer and the reactivation of its inactive mutated form represents one possibility for antitumor therapy. Reactivation leads to the initiation of apoptosis followed by the suppression of the malignant phenotype. Prima-1 and its methylated form Prima-1Met (also called APR-246) are compounds capable of reactivating mutated p53. Both are low-molecular substances that have been tested in a number of tumor cell lines and tumors bearing mutated p53.. This article summarizes what is currently known about both compounds, describes the possibilities of their use in anti-tumor therapy, and outlines the results of currently undergoing clinical trials of APR-246.. The results show that the mechanism of action of both compounds is still not clear. The mechanism is only known clearly in the case of Prima-1, and APR-246 is only known to induce apoptosis. The specificity of both substances for mutated p53 differs considerably and depends mainly on the cell model employed and the type of mutation. In addition to p53 reactivation itself, these compounds likely influence other mechanisms that also affect cytotoxic activity. Key words: Prima-1Met - APR-246 - Prima-1 - reactivation of p53 - apoptosis NPU I - LO1413. This work was supported by the project MEYS - NPS I - LO1413. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Accepted: 16. 07. 2018.

Topics: Apoptosis; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Humans; Neoplasms; Quinuclidines; Tumor Suppressor Protein p53

Topics: Antineoplastic Agents; Apoptosis Regulatory Proteins; Aza Compounds; bcl-2-Associated X Protein; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle; Cell Proliferation; Cellular Senescence; Cyclin-Dependent Kinase Inhibitor p21; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Proto-Oncogene Proteins; Signal Transduction; Tumor Suppressor Protein p53

TP53 (p53) is the most frequently mutated gene in cancer, being altered in approximately 50% of human malignancies. In most, if not all, cancers lacking mutation, wild-type (WT) p53 is inactivated by interaction with cellular (MDM2/MDM4) or viral proteins, leading to its degradation. Because of its near universal alteration in cancer, p53 is an attractive target for the development of new targeted therapies for this disease. However, until recently, p53 was widely regarded as ‘‘undruggable’’. This situation has now changed, as several compounds have become available that can restore wild-type properties to mutant p53 (e.g., PRIMA-1 and PRIMA-1MET). Other compounds are available that prevent the binding of MDM2/MDM4 to WT p53, thereby blocking its degradation (e.g., nutlins). Anti-mutant p53 compounds are potentially most useful in cancers with a high prevalence of p53 mutations. These include difficult-totreat tumors such as high grade serous ovarian cancer, triple-negative breast cancer and squamous lung cancer. MDM2/4 antagonists, on the other hand, are likely to be efficacious in malignancies in which MDM2 or MDM4 is overexpressed such as sarcomas, neuroblastomas and specific childhood leukemias. Presently, early clinical trials are ongoing evaluating the anti-mutant p53 agent, PRIMA-1MET, and specific MDM2–p53 nutlin antagonists.

Topics: Antineoplastic Agents; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle Proteins; Female; Genes, p53; Genetic Therapy; Humans; Molecular Targeted Therapy; Mutation; Neoplasms; Nuclear Proteins; Peptides; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-mdm2; Triple Negative Breast Neoplasms; Tumor Suppressor Protein p53

The tumor suppressor p53 has been implicated in a growing number of biological processes, including cell cycle arrest, senescence, apoptosis, autophagy, metabolism, and aging. Activation of p53 in response to oncogenic stress eliminates nascent tumor cells by apoptosis or senescence. p53 is regulated at the protein level by posttranslational modifications such as phosphorylation and acetylation. A p53 antisense gene, Wrap53, enhances p53 mRNA levels via the 5'UTR. Lack of Wrap53 transcripts that overlap with p53 abrogates the p53 DNA damage response. Around half of all human tumors carry p53 mutation that disrupt p53 specific DNA binding, and transcriptional transactivation of target genes. Reactivation of mutant p53 is a promising strategy for novel cancer therapy. The small molecule PRIMA-1 restores wild type conformation and DNA binding to mutant p53, induces mutant p53-dependent apoptosis, and inhibits tumor growth in vivo. The PRIMA-1 analog APR-246 is currently tested in a phase I clinical trial. Improved understanding of the p53 pathway should lead to better diagnosis and treatment of cancer in the future.

Topics: Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Mutation; Neoplasms; Tumor Suppressor Protein p53

The p53 tumor suppressor pathway blocks tumor development by triggering apoptosis or cellular senescence in response to oncogenic stress. A large fraction of human tumors carry p53 mutations that disrupt DNA binding of p53 and transcriptional regulation of target genes. Reconstitution of wild-type p53 in vivo triggers rapid elimination of tumors. Therefore, pharmacological reactivation of mutant p53 is a promising strategy for novel cancer therapy. Several approaches for identification of small molecules that target mutant p53 have been applied, including rational design and screening of chemical libraries. The compound PhiKan083 binds with high affinity to a crevice created by the Y220C mutation in p53 and stabilizes the mutant protein. The compound PRIMA-1 (p53 reactivation and induction of massive apoptosis) restores wild-type conformation to mutant p53 by binding to the core and induces apoptosis in human tumor cells. The PRIMA-1 analog APR-246 is currently tested in a clinical trial. Successful development of mutant p53-reactivating anticancer drugs should have a major impact on the treatment of cancer.

Topics: Animals; Antineoplastic Agents; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Drug Design; Drug Screening Assays, Antitumor; Genes, p53; Humans; Mutation; Neoplasms; Tumor Suppressor Protein p53

p53 mutation occurs in over half of all human tumors. Among the remaining tumors, although they may process a wild-type p53, the pathways of p53-induced cell-cycle arrest and apoptosis are deficient. Therefore, p53 serves as a unique molecular target for cancer therapy. This review focuses on the current progress regarding restoration of p53 function in human tumors for molecularly targeted therapy.. Targeting p53 for cancer therapy has been intensively pursued. CP-31398 was the first small molecule identified with the ability to restore the wild-type conformation to mutant p53. Subsequently, PRIMA-1 and ellipticine were found to be able to induce mutant p53-dependent cell death. Nutlin was developed to rescue wild-type p53 from degradation mediated by MDM2. More recently, p53 family members can be activated and therefore serve as substitutes of p53 in tumor cells and induce cell death.. Loss of p53 function is a characteristic of almost all human tumors. Recent advances demonstrate that reconstitution of p53 function is possible and practical as a promising antitumor strategy.

Topics: Antineoplastic Agents; Apoptosis; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle; Ellipticines; Genes, p53; Humans; Imidazoles; Models, Biological; Mutation; Neoplasms; Piperazines; Pyrimidines; Tumor Suppressor Protein p53

p53 is a molecule which is activated upon a DNA stress, such as gamma irradiation, UV, hypoxia, virus infection, and DNA damage, leading protection of cells by inducing target genes. The molecules activated by p53 induce apoptosis, cell cycle arrest, and DNA repair to conserve genome. In order to kill cancer cells, many strategies targeting p53 have been reported. Preclinical studies have demonstrated that overexpression of wt-p53 by adenovirus vector is capable of inducing apoptosis in cancers. Furthermore, restoration of mt-p53 into wild type by compound has been under development. In this review, clinical application of molecular targeting therapy for p53 is discussed.

Topics: Apoptosis; Aza Compounds; bcl-2-Associated X Protein; Bridged Bicyclo Compounds, Heterocyclic; Fas Ligand Protein; Gene Targeting; Genes, p53; Genetic Therapy; Humans; Membrane Glycoproteins; Neoplasms; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Pyrimidines; Tumor Suppressor Protein p53

Around half of all human tumours carry mutant p53. This allows escape from p53-induced cell cycle arrest and apoptosis. Many tumours express mutant p53 proteins at elevated levels. Restoration of wild-type p53 function should trigger massive apoptosis in tumour cells and thus eradicate tumours. Various types of small molecules have been identified that can restore native conformation and wild-type function to mutant p53. Such molecules may serve as leads for the development of novel efficient anticancer drugs.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Ellipticines; Gene Expression Regulation, Neoplastic; Genes, p53; Genetic Therapy; Humans; Mercaptoethylamines; Molecular Chaperones; Mutation; Neoplasms; Pyrimidines

The recent interaction cross-section-based formulation for radiation-induced direct cellular inactivation, mild and severe sublethal damage, DNA-repair and cell survival have been developed to accurately describe cellular repair, misrepair and apoptosis in TP53 wild-type and mutant cells. The principal idea of this new non-homologous repairable-homologous repairable (RHR) damage formulation is to separately describe the mild damage that can be rapidly handled by the most basic repair processes including the non-homologous end joining (NHEJ), and more complex damage requiring longer repair times and high-fidelity homologous recombination (HR) repair. Taking the interaction between these two key mammalian DNA repair processes more accurately into account has significantly improved the method as indicated in the original publication. Based on the principal mechanisms of 7 repair and 8 misrepair processes presently derived, it has been possible to quite accurately describe the probability that some of these repair processes when unsuccessful can induce cellular apoptosis with increasing doses of γrays, boron ions and PRIMA-1. Interestingly, for all LETs studied (≈0.3-160 eV/nm) the increase in apoptosis saturates when the cell survival reaches about 10% and the fraction of un-hit cells is well below the 1% level. It is shown that most of the early cell kill for low-to-medium LETs are due to apoptosis since the cell survival as well as the non-apoptotic cells agree very well at low doses and other death processes dominate beyond D > 1 Gy. The low-dose apoptosis is due to the fact that the full activation of the checkpoint kinases ATM and Chk2 requires >8 and >18 DSBs per cell to phosphorylate p53 at serine 15 and 20. Therefore, DNA repair is not fully activated until well after 1/2 Gy, and the cellular response may be apoptotic by default before the low-dose hyper sensitivity (LDHS) is replaced by an increased radiation tolerance as the DNA repair processes get maximal efficiency. In effect, simultaneously explaining the LDHS and inverse dose rate phenomena. The partial contributions by the eight newly derived misrepair processes was determined so they together accurately described the experimental apoptosis induction data for γ rays and boron ions. Through these partial misrepair contributions it was possible to predict the apoptotic response based solely on carefully analyzed cell survival data, demonstrating the usefulness of an accurate DNA repair-based ce

Topics: Animals; Apoptosis; Aza Compounds; Boron; Bridged Bicyclo Compounds, Heterocyclic; DNA Damage; DNA Repair; Fibroblasts; Gamma Rays; Ions; Linear Energy Transfer; Mammals; Mice; Neoplasms; Reactive Oxygen Species; Recombinational DNA Repair; Tumor Suppressor Protein p53

In response to genotoxic stress, the tumor suppressor p53 acts as a transcription factor by regulating the expression of genes critical for cancer prevention. Mutations in the gene encoding p53 are associated with cancer development. PRIMA-1 and eprenetapopt (APR-246/PRIMA-1

Topics: Antineoplastic Agents; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Crystallography, X-Ray; Humans; Loss of Function Mutation; Neoplasms; Protein Domains; Quinuclidines; Recombinant Proteins; Tumor Suppressor Protein p53

Restoration of wild-type p53 expression triggers cell death and eliminates tumors in vivo. The identification of mutant p53-reactivating small molecules such as PRIMA-1 opens possibilities for the development of more efficient anticancer drugs. Although the biological effects of PRIMA-1 are well demonstrated, little is known about its molecular mechanism of action. We show here that PRIMA-1 is converted to compounds that form adducts with thiols in mutant p53. Covalent modification of mutant p53 per se is sufficient to induce apoptosis in tumor cells. These findings might facilitate the design of more potent and specific mutant p53-targeting anticancer drugs.

Topics: Animals; Antineoplastic Agents; Apoptosis; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Drug Design; Humans; Mice; Mutation; Neoplasms; Protein Binding; Protein Structure, Tertiary; Tumor Suppressor Protein p53

PRIMA-1 (p53 reactivation and induction of massive apoptosis) is a chemical compound that was originally identified as a selective mutant p53-dependent growth suppressor by screening a library of low-molecular-weight compounds. However, its mechanism of action is unknown. In this study, we examined toxicity of PRIMA-1 to three premalignant human colorectal adenoma cell lines (RG/C2, BR/C1, and AA/C1) and four colorectal carcinoma cell lines (DLD-1, SW480, LOVO, and HCT116) and its mechanism of action. It selectively induced apoptosis only in the mutant p53 premalignant and malignant colon cell lines, but was not toxic to the wild-type p53 premalignant and malignant colon cell lines. Using stable transfectants of temperature-sensitive p53 mutant Ala(143) in null p53 H1299 lung cancer cells, we found that PRIMA-1 induced significantly more apoptosis in cells with mutant p53 conformation (37 degrees C) than the wild-type p53 conformation (32.5 degrees C). Cell cycle analysis indicated that its inhibition of cell growth was correlated with induction of G(2) arrest. Western blot analysis showed PRIMA-1 increased p21 and GADD45 expression selectively in the mutant p53 cells. However, Fas, Bcl-2 family proteins, and caspases were not involved in PRIMA-1-induced cell death. The c-Jun-NH(2)-kinase (JNK) inhibitor SP 600125, but not p38 mitogen-activated protein kinase inhibitor SB 203580 or extracellular signal-regulated kinase inhibitor PD 98059, blocked PRIMA-1-induced apoptosis. Transfection with a dominant-negative phosphorylation mutant JNK, but not a dominant-negative p38 or wild-type JNK, inhibited PRIMA-1-induced cell death, suggesting that the JNK pathway plays an important role in PRIMA-1-induced apoptosis. PRIMA-1 is a highly selective small molecule toxic to p53 mutant cells and may serve as a prototype for the development of new p53-targeting agents for therapy of premalignant and malignant cells.

Topics: Apoptosis; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Line; Cell Transformation, Neoplastic; Colonic Neoplasms; Humans; JNK Mitogen-Activated Protein Kinases; Lung Neoplasms; Neoplasms; Precancerous Conditions; Protein Kinase Inhibitors; RNA, Messenger; Signal Transduction; Temperature; Tumor Suppressor Protein p53

p53 is a major target for tumor therapy. Attempts have been made to restore or enhance p53 activity in tumor cells, including overexpression of exogenous p53 and small molecules that can rescue mutant p53. Notably, p53 peptides corresponding to the p53 carboxyl terminus can trigger a p53 response in both wild-type or mutant p53-containing cells. The recent protein transduction domain (PTD)-mediated cell entry might solve the obstacle of efficient delivery of peptides or large molecular biological cargos into cells. PTD-mediated transfer through the cell membrane occurs through a kind of endocytosis, macropinocytosis. Destabilization of macropinocytosomes by the influenza virus hemagglutinin protein (HA2) helps the escape of the PTD-cargo from macropinocytosomes and therefore significantly enhances the functional impact of transduced cargo.

Topics: Antineoplastic Agents; Aza Compounds; Binding Sites; Biological Transport; Bridged Bicyclo Compounds, Heterocyclic; Drug Carriers; Gene Products, tat; Genetic Therapy; Hemagglutinins, Viral; Humans; Hydrogen-Ion Concentration; Intracellular Membranes; Models, Biological; Mutation; Neoplasms; Peptides; Pinocytosis; Protein Conformation; Pyrimidines; Tumor Suppressor Protein p53; Viral Proteins

The tumor suppressor p53 inhibits tumor growth primarily through its ability to induce apoptosis. Mutations in p53 occur in at least 50% of human tumors. We hypothesized that reactivation of mutant p53 in such tumors should trigger massive apoptosis and eliminate the tumor cells. To test this, we screened a library of low-molecular-weight compounds in order to identify compounds that can restore wild-type function to mutant p53. We found one compound capable of inducing apoptosis in human tumor cells through restoration of the transcriptional transactivation function to mutant p53. This molecule, named PRIMA-1, restored sequence-specific DNA binding and the active conformation to mutant p53 proteins in vitro and in living cells. PRIMA-1 rescued both DNA contact and structural p53 mutants. In vivo studies in mice revealed an antitumor effect with no apparent toxicity. This molecule may serve as a lead compound for the development of anticancer drugs targeting mutant p53.

Topics: Animals; Antineoplastic Agents; Apoptosis; Aza Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Separation; Flow Cytometry; Genes, Reporter; Humans; In Situ Nick-End Labeling; Mice; Molecular Structure; Molecular Weight; Mutation; Neoplasms; Organic Chemicals; Protein Conformation; Transcriptional Activation; Transplantation, Heterologous; Tumor Cells, Cultured; Tumor Suppressor Protein p53