The outcomes of an impaired powerhouse in KRAS mutant lung adenocarcinoma cells by Elesclomol

Targeted delivery of elesclomol using a magnetic mesoporous platform improves prostate cancer treatment both in vitro and in vivo

BACKGROUND

To improve the anticancer properties of elesclomol (ELC), targeted theranostic nanoparticles (NPs; APT-PEG-Au-MMNPs@ELC) were designed to increase the selectivity of the drug delivery system (DDS).

MATERIALS AND METHODS

ELC was synthesized and entrapped in the open porous structure of magnetic mesoporous silica nanoparticles (MMNPs). The pore entrance of MMNPs was then blocked using gold gatekeepers. Finally, the external surfaces of the particles were grafted with functional polyethylene glycol (PEG) and EpCAM aptamer to generate biocompatible and targeted NPs. In the next step, the physicochemical properties of prepared NPs were fully evaluated and their anticancer potential was evaluated both in vitro and in vivo.

RESULTS

The targeted NPs were successfully synthesized with a final size diameter of 81.13 ± 7.41 nm. The results indicated a pH-dependent release pattern, which sustained for 72 h despite an initial rapid release. Upon exposure to APT-PEG-Au-MMNPs@ELC, higher cytotoxicity was observed in human prostate cancer cells (PC-3) as compared with control Chinese hamster ovary (CHO) cells, indicating higher specificity of targeted NPs against EpCAM-positive cancerous cells. Moreover, APT-PEG-Au-MMNPs@ELC could induce apoptosis in PC-3 cells. In vivo results on a PC-3 xenograft tumor model demonstrated that targeted NPs could significantly inhibit tumor growth and diminish severe side effects of ELC, compared to the free drug.

CONCLUSION

Collectively, APT-PEG-Au-MMNPs@ELC could be considered a promising theranostic platform for the targeted delivery of ELC to improve its therapeutic effects in prostate cancer.

Elesclomol, a copper-transporting therapeutic agent targeting mitochondria: from discovery to its novel applications

Copper (Cu) is an essential element that is involved in a variety of biochemical processes. Both deficiency and accumulation of Cu are associated with various diseases; and a high amount of accumulated Cu in cells can be fatal. The production of reactive oxygen species (ROS), oxidative stress, and cuproptosis are among the proposed mechanisms of copper toxicity at high concentrations. Elesclomol (ELC) is a mitochondrion-targeting agent discovered for the treatment of solid tumors. In this review, we summarize the synthesis of this drug, its mechanisms of action, and the current status of its applications in the treatment of various diseases such as cancer, tuberculosis, SARS-CoV-2 infection, and other copper-associated disorders. We also provide some detailed information about future directions to improve its clinical performance.

Comprehensive analysis of cuproptosis-related lncRNAs for prognostic significance and immune microenvironment characterization in hepatocellular carcinoma

Cuproptosis was characterized as a novel type of programmed cell death. Recently, however, the role of cuproptosis-related long noncoding RNAs (CRLs) in tumors has not yet been studied. Identifying a predictive CRL signature in hepatocellular carcinoma (HCC) and investigating its putative molecular function were the goals of this work. Initially, Pearson's test was used to assess the relationship between lncRNAs and cuproptosis-associated genes obtained from HCC data of The Cancer Genome Atlas (TCGA). By implementing differential expression and univariate Cox analysis, 61 prognostic CRLs were subsequent to the least absolute shrinkage and selection operator (LASSO) Cox regression analysis. A prognostic risk score model was then constructed to evaluate its ability to predict patients' survival when combined with clinicopathological parameters in HCC. The five-lncRNA prognostic signature categorized the HCC patients into high- and low-risk groups. The low-risk group exhibited more sensitivity to elesclomol than the high-risk one. Surprisingly, distinct mitochondrial metabolism pathways connected to cuproptosis and pivotal immune-related pathways were observed between the two groups via gene set enrichment analysis (GSEA). Meanwhile, there were substantial differences between the high-risk group and the low-risk group in terms of tumor-infiltrating immune cells (TIICs). Furthermore, a positive relationship was shown between the risk score and the expression of immune checkpoints. Additionally, differential expression of the five lncRNAs was confirmed in our own HCC samples and cell lines via RT-qPCR. Finally, in vitro assays confirmed that WARS2-AS1 and MKLN1-AS knockdown could sensitize HCC cells to elesclomol-induced cuproptosis. Overall, our predictive signature may predict the prognosis of HCC patients in an independent manner, give a better understanding of how CRLs work in HCC, and offer therapeutic reference for patients with HCC.

Crosstalk of four kinds of cell deaths defines subtypes of cutaneous melanoma for precise immunotherapy and chemotherapy

Background

Cell death patterns can give therapeutic and biological clues that facilitate the development of individualized treatments for this lethal form of skin cancer.

Methods

We employed unsupervised clustering to establish robust classifications based on the four kinds of cell death-associated gene expression of 462 melanoma patients in the Cancer Genome Atlas (TCGA) and tested their reproducibility in two independent melanoma cohorts of 558 patients. We then used dimensionality reduction of graph learning to display the different characteristics of cell death patterns and immune microenvironments.

Results

We examined 570 cell death-associated gene expression data of melanoma patients for exploration, independent verification, and comprehensive classification of five reproducible melanoma subtypes (CS1 to CS5) with different genomic and clinical features. Patients in death-inactive subtypes (CS1, CS2, and CS5) had the least immune and stromal cell infiltration, and their prognosis was the poorest. A death-active subtype (CS4), on the other hand, had the highest infiltrated immune and stromal cells and elevated immune-checkpoints. As a result, these patients had the highest response to immunotherapy and the best prognosis. An additional subtype (CS3) had more diversified cell death and immune characteristics with moderate prognoses. Based on graph learning, we successfully divided the CS3 subtype into two subgroups (group A and group B) with distinct survival outcomes and immune features. Finally, we identified eight potential chemical drugs that were specifically targeted for the therapy of melanoma subtypes.

Conclusions

This research defines the intrinsic subtypes of melanoma based on the crosstalk of four kinds of cell deaths, which affords a blueprint for clinical strategies and guiding precise immunotherapy and chemotherapy for melanoma patients.

Copper ionophore elesclomol selectively targets GNAQ/11-mutant uveal melanoma

Unlike cutaneous melanoma, uveal melanoma (UM) is characterized by mutations in GNAQ and GNA11 and remains a fatal disease because there is essentially no effective targeted therapy or immunotherapy available. We report the discovery of the copper ionophore elesclomol as a GNAQ/11-specific UM inhibitor. Elesclomol was identified in a differential cytotoxicity screen of an in-house tool compound library, and its in vivo pharmacological efficacy was further confirmed in zebrafish and mouse UM models. Mechanistically, elesclomol transports copper to mitochondria and produces a large amount of reactive oxygen species (ROS) as Cu(II) is reduced to Cu(I) in GNAQ/11-mutant UM cells, which selectively activates LATS1 kinase in the Hippo signaling pathway and consequently promotes YAP phosphorylation and inhibits its nuclear accumulation. The inactivation of YAP downregulates the expression of SNAI2, which in turn suppresses the migration of UM cells. These findings were cross validated by our clinical observation that YAP activation was found specifically in UM samples with a GNAQ/11 mutation. Furthermore, addition of binimetinib, a MEK inhibitor, to elesclomol increased its synthetic lethality to GNAQ/11-mutant UM cells, thereby overriding drug resistance. This effect was confirmed in an orthotopic xenograft model and in a patient-derived xenograft model of UM. These studies reveal a novel mechanistic basis for repurposing elesclomol by showing that copper homeostasis is a GNAQ/11-specific vulnerability in UM. Elesclomol may provide a new therapeutic path for selectively targeting malignant GNAQ/11-mutant UM.

Targeted apoptosis of myofibroblasts by elesclomol inhibits hypertrophic scar formation

Background

Hypertrophic scar (HS) is characterized by the increased proliferation and decreased apoptosis of myofibroblasts. Myofibroblasts, the main effector cells for dermal fibrosis, develop from normal fibroblasts. Thus, the stimulation of myofibroblast apoptosis is a possible treatment for HS. We aimed to explore that whether over-activated myofibroblasts can be targeted for apoptosis by anticancer drug elesclomol.

Methods

4′,6-diamidino-2-phenylindole staining, flow cytometry, western blotting, collagen gel contraction and immunofluorescence assays were applied to demonstrate the proapoptotic effect of elesclomol in scar derived myofibroblasts and TGF-β1 induced myofibroblasts. The therapeutic potential of elesclomol was investigated by establishing rabbit ear hypertrophic scar models.

Findings

Both 4′,6-diamidino-2-phenylindole staining and flow cytometry indicated that elesclomol targets myofibroblasts in vitro. Collagen gel contraction assay showed that elesclomol inhibited myofibroblast contractility. Flow cytometry and western blot analysis revealed that elesclomol resulted in excessive intracellular levels of reactive oxygen species(ROS), and caspase-3 and cytochrome c proteins. Moreover, compared with the control group, the elesclomol group had a significantly lower scar elevation index in vivo. Immunofluorescence assays for TUNEL and α-smooth muscle actin indicated that elesclomol treatment increased the number of apoptotic myofibroblasts.

Interpretation

The above results indicate that elesclomol exerted a significant inhibitory effect on HS formation via targeted myofibroblast apoptosis associated with increased oxidative stress. Thus, elesclomol is a promising candidate drug for the treatment of myofibroblast-related diseases such as HS.