P53 plays a key role in protecting the human genome from DNA-related mutations; however, it is one of the most frequently mutated genes in cancer. The P53 family members p63 and p73 were also shown to play important roles in cancer development and progression. Currently, there are various organic molecules from different structural classes of compounds that could reactivate the function of wild-type p53, degrade or inhibit mutant p53, etc. It was shown that: (1) the function of the wild-type p53 protein was dependent on the presence of Zn atoms, and (2) Zn supplementation restored the altered conformation of the mutant p53 protein. This prompted us to question whether the dependence of p53 on Zn and other metals might be used as a cancer vulnerability. This review article focuses on the role of different metals in the structure and function of p53, as well as discusses the effects of metal complexes based on Zn, Cu, Fe, Ru, Au, Ag, Pd, Pt, Ir, V, Mo, Bi and Sn on the p53 protein and p53-associated signaling.

Background: Nitric oxide (NO) has been linked to the pathogenesis of asbestos-related pleural diseases, including an extremely aggressive cancer called malignant pleural mesothelioma (MPM). Given that MPM cells are characterized by a higher expression of NO synthases and elevated NO production relative to normal cells, the use of NO-donor compounds could potentially saturate the cancerous cells with NO, triggering their death. Methods: We developed a novel class of NO prodrugs by merging two NO-releasing components, 1,2,5-oxadiazole 2-oxides (furoxans) and 1,2,4-oxadiazoles, and studied their NO-releasing characteristics in a time-dependent manner using the Griess assay. The cytotoxicity against two human MPM cell lines and non-cancerous lung fibroblasts was evaluated using a colorimetric MTT assay. Results: All compounds exhibited excellent NO-donating properties, surpassing the capacity of two reference NO donor compounds, 3-carbamoyl-4-(hydroxymethyl)furoxan (CAS-1609) and 4-ethoxy-3-phenylsulphonylfuroxan (CHF-2363), by at least 1.5–3 times. All oxadiazole hybrids demonstrated high cytotoxicity against MPM cell lines in a low micromolar range, comparable or higher than the cytotoxicity of the standard-of-care drug cisplatin. Conclusions: Notably, the novel compounds displayed a markedly greater selectivity towards cancerous cells than cisplatin when compared with non-cancerous lung fibroblasts, aligning with the intended design.

Resistance to cisplatin poses a significant challenge in cancer treatment for patients globally. Despite the continuous efforts of both the pharmaceutical industry and academia, no new platinum drugs have been approved for the treatment of cancers that have developed resistance to cisplatin-based chemotherapy regimens. Even in the new era of AI, the potential to accelerate the discovery of metal-based anticancer therapeutics has remained largely unexplored. Here, we present the first implementation of deep learning models for activity prediction of de novo designed platinum anticancer agents. Our approach overcomes historic limitations through a manually curated dataset of 4,078 platinum complexes with 18,995 IC50 values, as well as specialized algorithms resolving metal-specific representation challenges. For experimental validation, we predicted the likelihood of potential anticancer activity for 214,373 previously published platinum complexes in MCF-7, A549, A2780 and A2780cis cancer cell lines, synthesized and tested 20 of them, demonstrating strong agreement between predicted and observed activity. Additionally, using de novo fragment assembly approach we designed and successfully synthesized a novel bis-carbene platinum(II) complex, PlatinAI. The experimentally determined cytotoxicity of PlatinAI in MCF-7, A549, A2780 and A2780cis cancer cell lines was in a perfect agreement with the model prediction. PlatinAI demonstrated superior activity compared to cisplatin in cisplatin-resistant cell lines and exhibited a distinct mechanism of action, not reliant on the formation of DNA adducts. This research sets the stage for the development of AI-assisted platforms that enable data-driven design of next-generation platinum therapies, offering improved efficacy and the ability to overcome resistance to current anticancer treatments.

Background: Malignant pleural mesothelioma (MPM) is an aggressive, asbestos-associated cancer characterized by dysregulated nitric oxide (NO) signaling and increased NO levels that facilitate tumor progression. Paradoxically, this aberrant NO environment creates a therapeutic vulnerability that can be exploited by NO-donor prodrugs, which overwhelm cellular defenses with cytotoxic concentrations of NO, inducing nitrosative stress and apoptosis. Within this framework, oxadiazole-based scaffolds have emerged as a promising platform for prodrug development owing to their versatile chemistry and potential as novel NO donors or synergistic agents. In our previous studies, we developed several series of hybrid architectures incorporating 1,2,5-oxadiazole 2-oxide (furoxan) and 1,2,4-oxadiazole scaffolds, producing compounds with diverse and tunable NO-donor activities. We further observed that the cytotoxicity of these hybrids was significantly influenced by the substituents introduced at position 3 of the furoxan ring. Methods: We designed and synthesized a series of bis(1,2,4-oxadiazolyl)furoxans to systematically investigate their NO-donating capacity, cytotoxicity against MPM cell lines, selectivity over healthy lung fibroblasts, and underlying anticancer mechanisms. Results: The bis(1,2,4-oxadiazolyl)furoxans exhibited lower overall cytotoxicity but significantly higher selectivity compared with previously studied 3-cyano-4-(1,2,4-oxadiazolyl)furoxans. Their NO-releasing properties showed a strong correlation with their ability to induce mitochondrial damage, as evidenced by membrane depolarization. Moreover, the incorporation of specific substituents, such as a furan ring, on the 1,2,4-oxadiazole moiety introduced an additional mechanism of action through the induction of reactive oxygen species. Conclusions: Analysis of cancer cell death confirmed that these compounds acted through a multimodal mechanism dependent on both NO release and the specific substituents on the 1,2,4-oxadiazole moiety.