Search Results (45)

Chimeric compounds represent a promising strategy in cancer therapy by simultaneously targeting multiple pathways responsible for tumour growth and survival. Their structure comprises two or more pharmacophores connected through suitable chemical linker. These dual or multi-functional drugs can interact with several biological targets for a more pronounced pharmacological effect. In order to identify new multi-targeting agents with anticancer efficacy, we designed and synthesised a series of novel multi-functional molecules by covalently linking antitumor compounds dichloroacetate (DCA) and Nutlin-3a. The design was aimed at addressing two critical events in cancer: (1) the Warburg effect and (2) the dysregulations of protein p53 pathway, both of which are directly linked to the predominant survival and aggressive proliferation of malignant cells. DCA reactivate oxidative phosphorylation by inhibiting mitochondria pyruvate dehydrogenase kinase (PDK), thereby unlocking the Warburg metabolism of cancer cells and its antiapoptosis state. Concurrently, Nutlin-3a restores the protective function of the “genome guardian” p53 protein, by blocking its antagonist oncoprotein E3 ligase MDM2. Chimeric compounds were obtained using a chemoenzymatic multi-step procedure that included a key lipase-catalysed asymmetric reaction. Biological evaluation of the synthesised Nutlin-DCA chimeras in a panel of three cancer cell lines demonstrated promising results in vitro. Specifically, compounds rac-19a, rac-19b, rac-20a, rac-20b and enantioenriched 20a caused a statistically significant reduction in cell viability at micromolar concentrations. These findings suggest that targeting both the Warburg effect and the p53 pathway with a single molecule is a viable approach for future cancer therapeutic development. Full article

Transcription factors (TFs) are proteins that control gene expression by binding to specific DNA sequences and are essential for cell development, differentiation, and homeostasis. Dysregulation of TFs is implicated in numerous diseases, including cancer, autoimmune disorders, and neurodegeneration. While TFs were traditionally considered “undruggable” due to their lack of well-defined binding pockets, recent advances have made it possible to modulate their activity using diverse pharmacological strategies. Major TF families include NF-κB, p53, STATs, HIF-1α, AP-1, Nrf2, and nuclear hormone receptors, which take part in the regulation of inflammation, tumor suppression, cytokine signaling, hypoxia and stress response, oxidative stress, and hormonal response, respectively. TFs can perform multiple functions, participating in the regulation of opposing processes depending on the context. NF-κB, for instance, plays dual roles in immunity and cancer, and is targeted by proteasome and IKKβ inhibitors. p53, often mutated in cancer, is reactivated using MDM2 antagonist Nutlin-3, refunctionalizing compound APR-246, or stapled peptides. HIF-1α, which regulates hypoxic responses and angiogenesis, is inhibited by agents like acriflavine or stabilized in anemia therapies by HIF-PHD inhibitor roxadustat. STATs, especially STAT3 and STAT5, are oncogenic and targeted via JAK inhibitors or novel PROTAC degraders, for instance SD-36. AP-1, implicated in cancer and arthritis, can be inhibited by T-5224 or kinase inhibitors JNK and p38 MAPK. Nrf2, a key antioxidant regulator, can be activated by agents like DMF or inhibited in chemoresistant tumors. Pharmacological strategies include direct inhibitors, activators, PROTACs, molecular glues, and epigenetic modulators. Challenges remain, including the structural inaccessibility of TFs, functional redundancy, off-target effects, and delivery barriers. Despite these challenges, transcription factor modulation is emerging as a viable and promising therapeutic approach, with ongoing research focusing on specificity, safety, and efficient delivery methods to realize its full clinical potential. Full article

Ferroptosis, an iron-dependent cell death driven by lipid peroxidation, is regulated by key mediators including glutathione peroxidase 4 (GPX4) and nuclear factor erythroid 2-related factor 2 (Nrf2). Kaposi’s sarcoma-associated herpesvirus (KSHV) encodes latency-associated nuclear antigen (LANA), a multifunctional protein critical for viral persistence. Although studies reported that KSHV infection enhanced cellular resistance to ferroptosis, the specific role of LANA in this process remains unexplored. Here, we demonstrate that LANA unexpectedly promotes ferroptosis. In KSHV-positive iSLK.219 cells, LANA knockdown significantly attenuated RSL-3-induced ferroptosis, whereas LANA overexpression sensitized HeLa cells to ferroptotic death. Quantitative analysis revealed that LANA-depleted cells exhibited significantly elevated ROS accumulation (p < 0.01), whereas LANA-overexpressing cells maintained reduced ROS levels during challenge with the ferroptosis inducer RSl-3. Mechanistically, LANA suppressed glutathione peroxidase 4 (GPX4) expression, reduced nuclear factor erythroid 2-related factor 2 (Nrf2) expression and impaired its nuclear translocation, and upregulated mouse double minute 2 homolog (MDM2) expression. Pharmacological inhibition of Nrf2 (ML385) or MDM2 (nutlin3a) reversed the ferroptotic effects of LANA knockdown or overexpression, respectively. These findings reveal a pro-ferroptotic role of LANA via Nrf2/GPX4 suppression and MDM2 activation. Full article

The p53 tumor suppressor is best known for controlling the cell cycle, apoptosis, DNA repair, and metabolism, but it also regulates immunity and is able to impede the live cycle of viruses. For this reason, these infectious agents encode proteins which inactivate p53. However, what is less known is that p53 can also be inactivated by human pathogenic bacteria. It is probably not due to collateral damage, but specific targeting, because p53 could interfere with their multiplication. The mechanisms of the antibacterial activity of p53 are poorly known. However, they can be inferred from the results of high-throughput studies, which have identified more than a thousand p53-activated genes. As it turns out, many of these genes code proteins which have proven or plausible antibacterial functions like the efficient detection of bacteria by pattern recognition receptors, the induction of pro-inflammatory pyroptosis, the recruitment of immune cells, direct bactericidal activity, and the presentation of bacterial metabolites to lymphocytes. Probably there are more antibacterial, p53-regulated functions which were overlooked because laboratory animals are kept in sterile conditions. In this review, we present the outlines of some intriguing antibacterial mechanisms of p53 which await further exploration. Definitely, this area of research deserves more attention, especially in light of the appearance of antibiotic-resistant bacterial strains. Full article

Triple-negative breast cancer (TNBC) represents the most aggressive breast carcinoma subtype lacking efficient therapeutic options. A promising approach in cancer treatment is the pharmacological inhibition of murine double minute 2 (MDM2)-p53 interaction inducing apoptosis in p53 wild-type tumors. However, the role of MDM2 in TNBC with primarily mutant p53 is not well understood. We here selected the clinical-stage MDM2 inhibitors Idasanutlin and Milademetan and investigated their anti-tumoral effects in TNBC. When we analyzed anti-tumor activity in the TNBC cell lines MDA-MB-231, MDA-MB-436, and MDA-MB-468, cellular viability was efficiently reduced, with half maximal inhibitory concentration (IC₅₀) values ranging between 2.00 and 7.62 µM being up to 11-fold lower compared to the well-characterized non-clinical-stage MDM2 inhibitor Nutlin-3a. Furthermore, caspase-3/7 activity was efficiently induced. Importantly, the IC₅₀ values for MDM2 inhibition were equally observed in HCT116 p53^+/+ or HCT116 p53^−/− cells. Finally, the IC₅₀ was significantly higher in non-malignant MCF-10A cells than in TNBC cells. Taken together, Idasanutlin and Milademetan show a potent anti-tumor activity in TNBC cell culture models by efficiently inducing tumor cell death via apoptosis. This effect was observed despite an inactivating p53 mutation and was apparently independent of p53 expression. Our data suggest that MDM2 is a promising target in TNBC and clinical-stage MDM2 inhibitors should be further evaluated for their potential therapeutic application. Full article

Background: Ezetimibe is used to treat cardiovascular disease as it blocks the sterol transporter Niemann-Pick C1-Like 1 (NPC1CL1) protein. However, recent evidence indicates that Ezetimibe inhibits several cancers indirectly by reducing circulating cholesterol or via specific signalling pathways. Methods and Results: Our in silico studies indicate that Ezetimibe binds to the Tp53 binding domain in Mdm2, forming a more thermodynamically stable complex than nutlin3a. Furthermore, a docking study of the newly developed inhibitors—RG7388 and RG7112—was conducted. This further showed lower binding energies of −6.337 kcal/mol and −6.222 kcal/mol, respectively, when compared to the −7.919 kcal/mol exhibited by Ezetimibe. We show that Ezetimibe inhibits the growth of several cancer cell lines at concentrations that are not toxic to a normal cell line. Conclusions: Thus, Ezetimibe is probably active against cancers that overexpress Mdm2. Moreover, inhibitors of RBBP6 may be combined with Ezetimibe for effective anticancer activity. Due to poor oral bioavailability, Ezetimibe must be administered parenterally for cancer treatment. Full article

Thyroid cancer is the most common endocrine malignancy in the United States, with an overall favorable prognosis. However, some patients experience poor outcomes due to the development of resistance to conventional therapies. Genetic alterations, including mutations in BRAF, Met, and p53, play critical roles in thyroid cancer progression, with the BRAF V600E mutation detected in over 60% of cases. This study investigates the tumor-suppressive role of Annexin A7 (ANXA7) in thyroid cancer, focusing on its potential impact on tumor behavior and therapeutic response. Our analysis, which included RNA sequencing and protein profiling, revealed reduced ANXA7 expression in thyroid cancer cells, particularly in those harboring the BRAF V600E mutation. Upon treatment with inhibitors targeting BRAF and MEK, ANXA7 expression increased, leading to reduced phosphorylation of ERK and activation of apoptotic pathways. Additionally, we identified the cyclin-dependent kinase inhibitor p21 as a key player in modulating resistance to BRAF inhibitors. Combination therapies aimed at concurrently increasing p21 and ANXA7 levels resulted in a marked enhancement of apoptosis. These findings suggest a previously uncharacterized regulatory network involving the ANXA7/p21/BRAF/MAPK/p53 axis, which may contribute to drug resistance in thyroid cancer. This study provides new insights into overcoming resistance to BRAF and MAPK inhibitors, with implications for treating thyroid cancer and potentially other BRAF-mutant tumors. Future efforts will focus on high-throughput screening approaches to explore ANXA7-targeted therapeutic strategies for thyroid cancer. Full article

This study evaluated ethosomes as a novel nanodelivery system for nutlin-3a, a known MDM2 inhibitor and activator of the p53 pathway, to improve nutlin-3a’s poor solubility, limiting its bio-distribution and therapeutic efficacy. The potential of nutlin-3a-loaded ethosomes was investigated on two in vitro models of melanoma: the HT144 cell line p53^wild-type and the SK-MEL-28 cell line p53^mutated. Nutlin-3a-loaded ethosomes were characterized for their physicochemical properties and used to treat melanoma cells at different concentrations, considering nutlin-3a solution and empty ethosomes as controls. The biological effects on cells were evaluated 24 and 48 h after treatment by analyzing the cell morphology and viability, cell cycle, and apoptosis rate using flow cytometry and the p53 pathway’s activation via Western blotting. The results indicate that ethosomes are delivery systems able to maintain nutlin-3a’s functionality and specific biological action, as evidenced by the molecular activation of the p53 pathway and the biological events leading to cell cycle block and apoptosis in p53^wild-type cells. Nutlin-3a-loaded ethosomes induced morphological changes in the HT144 cell line, with evident apoptotic cells and a reduction in the number of viable cells of over 80%. Furthermore, nutlin-3a-loaded ethosomes successfully modulated two p53-regulated proteins involved in survival/apoptosis, with up to a 2.5-fold increase in membrane TRAIL-R2 and up to an 8.2-fold decrease in Notch-1 (Notch intracellular domain, NICD) protein expression. The expression of these molecules is known to be altered or dysfunctional in a large percentage of melanoma tumors. Notably, ethosomes, regardless of their nutlin-3a loading, exhibited the ability to reduce HT144 melanoma cellular migration, as assessed in real time using xCELLigence, likely due to the modification of lipid rafts, suggesting their potential antimetastatic properties. Overall, nutlin-3a delivery using ethosomes appears to be a significantly effective means for upregulating the p53 pathway and downregulating active Notch-1, while also taking advantage of their unexpected ability to reduce cellular migration. The findings of this study could pave the way for the development of specific nutlin-3a-loaded ethosome-based medicinal products for cutaneous use. Full article

Herein we present the biocatalysed preparation of a mono-N-carbamate-protected precursor of antitumoral Nutlin-3a through enantioselective alkoxycarbonylation of meso-1,2-disubstituted-1,2-diaminoethane using enzyme lipases and dialkyl carbonates as acylating agents. A series of supported or free lipase enzymes were screened in combination with commercially available diallyl, diethyl and dimethyl carbonates. The reactions were conducted at different temperatures, for different reaction times and with variable co-solvent systems to evaluate the effects on the enzyme catalytic activity. The best results in terms of conversion, enantiomeric excess and yield were obtained when lipase from Candida antarctica B (CAL-B) was used with diallyl carbonate (DAC) when conducting the reaction solventless at 75 °C. Full article

The p53 tumor suppressor protein activates various sets of genes depending on its covalent modifications, which are controlled by the nature and intensity of cellular stress. We observed that actinomycin D and nutlin-3a (A + N) collaborate in inducing activating phosphorylation of p53. Our recent transcriptomic data demonstrated that these substances strongly synergize in the upregulation of DUSP13, a gene with an unusual pattern of expression, coding for obscure phosphatase having two isoforms, one expressed in the testes and the other in skeletal muscles. In cancer cells exposed to A + N, DUSP13 is expressed from an alternative promoter in the intron, resulting in the expression of an isoform named TMDP-L1. Luciferase reporter tests demonstrated that this promoter is activated by both endogenous and ectopically expressed p53. We demonstrated for the first time that mRNA expressed from this promoter actually produces the protein, which can be detected with Western blotting, in all examined cancer cell lines with wild-type p53 exposed to A + N. In some cell lines, it is also induced by clinically relevant camptothecin, by nutlin-3a acting alone, or by a combination of actinomycin D and other antagonists of p53-MDM2 interaction—idasanutlin or RG7112. This isoform, fused with green fluorescent protein, localizes in the perinuclear region of cells. Full article

Mesenchymal stem cells (MSCs) are an integral part of the tumor microenvironment (TME); however, their role is somewhat controversial: conflicting reports suggest that, depending on the stage of tumor development, MSCs can either support or suppress tumor growth and spread. Additionally, the influence of MSCs on drug resistance is also ambiguous. Previously, we showed that, despite MSCs proliferating significantly more slowly than cancer cells, there are chemotherapeutic drugs which proved to be similarly toxic to both cell types. Here we established 2D co-cultures and 3D co-culture spheroids from different ratios of GFP-expressing, adipose tissue-derived MSCs and A431 epidermoid carcinoma cells tagged with mCherry to investigate the effect of MSCs on cancer cell growth, survival, and drug sensitivity. We examined the cytokine secretion profile of mono- and co-cultures, explored the inner structure of the spheroids, applied MSC-(nutlin-3) and cancer cell-targeting (cisplatin) treatments separately, monitored the response with live-cell imaging and identified a new, double-fluorescent cell type emerging from these cultures. In 2D co-cultures, no effect on proliferation or drug sensitivity was observed, regardless of the changes in cytokine secretion induced by the co-culture. Conversely, 3D spheroids developed a unique internal structure consisting of MSCs, which significantly improved cancer cell survival and resilience to treatment, suggesting that physical proximity and cell–cell connections are required for MSCs to considerably affect nearby cancer cells. Our results shed light on MSC–cancer cell interactions and could help design new, better treatment options for tumors. Full article

Cellular senescence, a state of irreversible growth arrest, is implicated in various age-related pathologies, including skin aging. In this study, we investigated the role of CLCA2, a calcium-activated chloride channel accessory protein, in cellular senescence and its implications for skin aging. Utilizing UVB and Nutlin3a-induced senescence models, we observed the upregulation of CLCA2 at both transcriptomic and proteomic levels, suggesting its involvement in senescence pathways. Further analysis revealed that the depletion of CLCA2 led to accelerated senescence onset, characterized by classic senescence markers and a unique secretome profile. In 3D skin equivalent models, SEs constructed with CLCA2 knockdown fibroblasts exhibited features reminiscent of aged skin, underscoring the importance of CLCA2 in maintaining skin homeostasis. Our findings highlight CLCA2 as a novel regulator of cellular senescence and its potential implications for skin aging mechanisms. Full article

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. Full article

The skin’s protective mechanisms, in some cases, are not able to counteract the destructive effects induced by UV radiations, resulting in dermatological diseases, as well as skin aging. Nutlin-3, a potent drug with antiproliferative activity in keratinocytes, can block UV-induced apoptosis by activation of p53. In the present investigation, ethosomes and transethosomes were designed as delivery systems for nutlin-3, with the aim to protect the skin against UV damage. Vesicle size distribution was evaluated by photon correlation spectroscopy and morphology was investigated by cryogenic transmission electron microscopy, while nutlin-3 entrapment capacity was evaluated by ultrafiltration and HPLC. The in vitro diffusion kinetic of nutlin-3 from ethosomes and transethosomes was studied by Franz cell. Moreover, the efficiency of ethosomes and transethosomes in delivering nutlin-3 and its protective role were evaluated in ex vivo skin explants exposed to UV radiations. The results indicate that ethosomes and transethosomes efficaciously entrapped nutlin-3 (0.3% w/w). The ethosome vesicles were spherical and oligolamellar, with a 224 nm mean diameter, while in transethosome the presence of polysorbate 80 resulted in unilamellar vesicles with a 146 nm mean diameter. The fastest nutlin-3 kinetic was detected in the case of transethosomes, with permeability coefficients 7.4-fold higher, with respect to ethosomes and diffusion values 250-fold higher, with respect to the drug in solution. Ex vivo data suggest a better efficacy of transethosomes to promote nutlin-3 delivery within the skin, with respect to ethosomes. Indeed, nutlin-3 loaded transethosomes could prevent UV effect on cutaneous metalloproteinase activation and cell proliferative response. Full article

The interaction between the tumor suppressor protein p53 and its negative regulator, the MDM2 oncogenic protein, has gained significant attention in cancer drug discovery. In this study, 120 lignans reported from Ferula sinkiangensis and Justicia procumbens were assessed for docking simulations on the active pocket of the MDM2 crystal structure bound to Nutlin-3a. The docking analysis identified nine compounds with higher docking scores than the co-crystallized reference. Subsequent AMDET profiling revealed satisfactory pharmacokinetic and safety parameters for these natural products. Three compounds, namely, justin A, 6-hydroxy justicidin A, and 6′-hydroxy justicidin B, were selected for further investigation due to their strong binding affinities of −7.526 kcal/mol, −7.438 kcal/mol, and −7.240 kcal/mol, respectively, which surpassed the binding affinity of the reference inhibitor Nutlin-3a (−6.830 kcal/mol). To assess the stability and reliability of the binding of the candidate hits, a molecular dynamics simulation was performed over a duration of 100 ns. Remarkably, the thorough analysis demonstrated that all the hits exhibited stable molecular dynamics profiles. Based on their effective binding to MDM2, favorable pharmacokinetic properties, and molecular dynamics behavior, these compounds represent a promising starting point for further refinement. Nevertheless, it is essential to synthesize the suggested compounds and evaluate their activity through in vitro and in vivo experiments. Full article