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BACKGROUND AND PURPOSE: Impairment of the tumour suppressor p53 pathway is a major event in human cancers, making p53 activation one of the most attractive therapeutic strategies to halt cancer. Here, we have identified a new selective p53 activator and investigated its potential as an anticancer agent. EXPERIMENTAL APPROACH: Anti‐proliferative activity of the (R)‐tryptophanol‐derived bicyclic lactam SYNAP was evaluated in a range of human cancer cells with different p53 status. The anticancer activity and mechanism of action of SYNAP was studied in two‐ and three‐dimensional models of human colon adenocarcinoma HCT116 cells with wild‐type p53 and corresponding p53‐null isogenic derivative cells, alone and in combination with known chemotherapeutic agents. KEY RESULTS: SYNAP showed anti‐proliferative effect in human cancer cells dependent on p53 status. In HCT116 cells, SYNAP caused p53‐dependent growth inhibition, associated with cell cycle arrest and apoptosis, anti‐migratory activity and regulation of the expression of p53 transcriptional targets. Data also indicated that SYNAP targeted p53, inhibiting its interaction with its endogenous inhibitors, murine double minute (MDM)2 and MDMX. Moreover, SYNAP sensitized colon cancer cells to the cytotoxic effect of known chemotherapeutic agents. SYNAP did not induce acquired or cross‐resistance and re‐sensitized doxorubicin‐resistant colon cancer cells to chemotherapy. Additionally, SYNAP was non‐genotoxic and had low cytotoxicity against normal cells. CONCLUSION AND IMPLICATIONS: SYNAP revealed encouraging anticancer activity, either alone or in combination with known chemotherapeutic agents, in colon cancer cells. Apart from its promising application in cancer therapy, SYNAP may provide a starting point for improved p53 activators.

Introduction: The tumor suppressor protein p53 is frequently mutated in human cancer, which is commonly related to poor prognosis. Thus, reactivation of wild-type functions to mutant p53 is an attractive anticancer therapeutic strategy (1). Indeed, many efforts have been developed to target mutant p53. In a recent work, our group discovered the small molecule SLMP53-1, which restores the wild-type activity to mutant p53R280K with promising in vitro and in vivo antitumor activity results (2; 3). Aims: The present work aims to unravel the binding of SLMP53-1 to mutant p53R280K. Materials and methods: With that purpose, two strategies were defined: i) to assess the thermal stabilization of mutant p53R280K, induced by the binding of SLMP53-1 to mutant p53, in a cellular context by Cellular Thermal Shift Assay (CETSA); and ii) to produce p53R280K for biophysical binding assays, including MicroScale Thermophoresis (MST), Saturation-Transfer Difference NMR (STD-NMR) and X-ray crystallography. Results: By CETSA, we showed that SLMP53-1 induces p53R280K thermal stabilization, confirming the binding of SLMP53-1 to p53R280K. Recombinant p53R280K protein (core domain) was successfully produced and purified from E. coli BL21(DE3). So far, crystals of apo p53R280K and with SLMP53-1 were obtained. Co-crystallization optimization, MST and STD-NMR experiments are underway. Conclusions: With this work, the SLMP53-1 binding to p53R280K was confirmed and its characterization is in progress. This integrated study will contribute to understand the biology and pharmacology of p53 mutant forms and to the rational design of improved reactivators of mutant p53., info:eu-repo/semantics/publishedVersion

N-Methyl-D-Aspartate (NMDA) receptors are fundamental for the normal function of the central nervous system and have an important role in memory and learning. An overactivation of these receptors results into an influx of excess of calcium cation (Ca2+) leading to neuronal loss associated with major degenerative disorders including Parkinson’s and Alzheimer’s diseases. Since the 80s, a big interest emerged of both academia and industry to develop drugs targeting the NMDA subtype of glutamate receptors with potential application for the treatment of some degenerative disorders. The main successes were amantadine (39) and memantine (40), two compounds which belong to adamantanes’s family, approved by FDA and used currently in the clinic. Another important area of therapeutic interest is cancer, which is considered the first and second causes of deaths on developed and developing countries, respectively. Statistical studies estimate that in 2030 the number of deaths caused by this disease will be 13.2 million. For this reason, it is essential the discovery of new methodologies and therapeutic agents for the treatment of cancer. The main goal of this thesis is the enantioselective synthesis of small molecules, more precisely phenylalaninol- and tryptophanol-derived bicyclic lactams, with potential application as NMDA receptor antagonists and antitumor agents, respectively. From the library of phenylalaninol derivatives, two new were promising NMDA receptor antagonists were identified. In particular, compounds 1c and 1d revealed to be more active than the hit compound, 1a, with IC50 values of 39 μM and 36 μM, respectively. Derivatives of another amino alcohol, (1S, 2R)-(−)-cis-1-amino-2-indanol, were also synthesized and a new antagonist, compound 6b, was identified with IC50 value of 51 μM. A hit-to-lead process of these three compounds was performed and the determination of respective IC50 values is in progress. For the series of tryptophanol derivatives, a hit compound (4c) was identified which revealed an IC50 value of 60 μM in MCF-7 cell lines (breast adenocarcinoma). A structural derivatization was performed, leading to five more active compounds (8b-f) with IC50 values between 6.7 and 9.0 μM, for the same cancer cell line. Furthermore, these five compounds were also evaluated in other cancer cell lines, and revealed to be selective for MCF-7 cell line, as well as non-toxic for normal cells (HEK 293).