Role of iron in cancer development by viruses

Nanozyme-like single-atom catalyst combined with artesunate achieves photothermal-enhanced nanocatalytic therapy in the near-infrared biowindow

Selectively generating active free radical (AFR) in tumor microenvironment (TME) can promote irreversible oxidation of biomolecules and damage tumor cells, resulting in effective tumor inhibition. However, therapeutic efficacy of AFR-based tumor suppression approaches is often limited by insufficient amount of H₂O₂ or O₂ within TME. To overcome this obstacle, we design a pH/photothermal dual responsive nanosystem (PFeSA@AS) for combined photothermal and nanocatalytic therapy in the near-infrared biowindow. Here the Fe single-atom dispersed N, S-doped carbon nanosheets (FeSA) nanozyme is dispersed by phospholipid-polyethylene glycol-amine (DSPE-PEG-NH₂), and further loads artesunate (AS) via an amide reaction. Upon 808-nm laser irradiation in TME, the AS is released and further be catalyzed by the FeSA nanozyme to produce cytotoxic C-centered AFRs, and further be accelerated due to the photothermal conversion performance of FeSA (23.35%). The nanocatalytic process of FeSA nanozyme is realized by density functional theory (DFT). The tumor inhibition rates of a CT26 xenograft model is 92% through a photothermal-enhanced nanocatalytic synergistic therapy, and negligible systematic toxicity is observed. This work offers a potential paradigm of multifunctional single atomic catalysts (SACs) for enhancing tumor nanocatalytic therapy. STATEMENT OF SIGNIFICANCE: We designed a pH/photothermal dual responsive nanosystem (PFeSA@AS) for nanocatalytic therapy: (1) the nanosystem responsively releases AS under 808-nm laser irradiation in TME; (2) FeSA in the nanosystem can act as heme mimetic to convert AS into high cytotoxic C-centered free radicals for nanocatalytic therapy; (3) the photothermal conversion performance of FeSA further enhances the catalytic process to yield abundant AFR. Both in vitro and in vivo results demonstrate that this nanosystem can efficiently inhibit tumor growth through a photothermal-enhanced nanocatalytic synergistic therapy.

Ferroptosis-related NFE2L2 and NOX4 Genes are Potential Risk Prognostic Biomarkers and Correlated with Immunogenic Features in Glioma

Ferroptosis is a newfound mode of regulated cell death that may have potential to associate with prognostic or diagnostic factors in glioma. In this research, 5 genes related to glioma were screened through the FerrDb database, and we analyzed the combination between genes and glioma of survival and prognosis via TCGA, GEPIA, TIMER, and other databases. Survival curve and prognostic analysis showed that the overexpression of NFE2L2 and NOX4, respectively, has a remarkable link with a worse prognosis in glioma. Then, the association between the expression of the two genes and tumor-infiltrating immune cells level was explored based on the GSCA, and the immunity of NFE2L2 and NOX4 based on the TISIDB database was also investigated. In glioma, especially GBM, there is a strong association between gene expression and immune infiltration, even in macrophages, nTreg, and Th2 cells, which play immunosuppressive functions in TME. In conclusion, these results indicate that NFE2L2 and NOX4 could be risk prognosis biomarkers in glioma, and they bound up with immune infiltration and tumor immunity in tumorigenesis.

Norcantharidin down-regulates iron contents in the liver and spleen of lipopolysaccharide-treated mice

Objective

The inhibiting effect of Norcantharidin (NCTD) on IL-6 (interleukin-6) and STAT3 and the involvement of the IL-6/STAT3 pathway in hepcidin expression prompted us to speculate that NCTD could affect iron metabolism.

Methods

We examined the effects of NCTD on serum iron (SI) and transferrin (Tf) saturation, iron and ferritin light chain (FTL), transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), ferroportin 1 (Fpn1), iron regulatory protein 1 (IRP1) and hepcidin, as well as IL-6 and STAT3 in the liver, spleen and duodenum of mice treated with lipopolysaccharide (LPS) in vivo, using RT-PCR, Western blotting and immunofluorescence analysis.

Results

NCTD could increase SI and Tf saturation and reduce tissue iron and FTL content by affecting expression of cell-iron transport proteins TfR1, DMT1 and Fpn1. The impact of NCTD on TfR1, DMT1 and Fpn1 expression is mediated by up-regulating IRP1 and down-regulating hepcidin expression, while NCTD-induced down-regulation of hepcidin is mediated by the IL-6/STAT3 signalling pathway in LPS-treated mice.

Conclusions

NCTD affects iron metabolism by modifying the expression of IL-6/JAK2/STAT3/hepcidin and IRP1 and suggest that the ability of NCTD to reduce tissue iron contents may be a novel mechanism associated with the anti-cancer effects of NCTD.

Characterization of ferroptosis signature to evaluate the predict prognosis and immunotherapy in glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common type of brain cancer with poor survival outcomes and unsatisfactory response to current therapeutic strategies. Recent studies have demonstrated that ferroptosis-related genes (FRGs) are linked with the occurrence and development of GBM and may become promising biological indicators in GBM therapy.

METHODS

We systematically assessed the relationship between FRGs expression profiles and prognosis in glioma patients based on the Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) datasets to establish a risk score model according to the gene signature of multiple survival-associated DEGs. Further, the differences between the tumor microenvironment score, immune cell infiltration, immune checkpoint expression levels, and drug sensitivity in the high- and low-risk group are analyzed through a variety of algorithms in R software.

RESULTS

GBM patients were divided into two subgroups (high- and low-risk) according to the established risk score model. Patients in the high-risk group showed significantly reduced overall survival compared with those in the low-risk group. Also, we found that the high-risk group showed higher ImmuneScore and StromalScore, while different subgroups have significant differences in immune cell infiltration, immune checkpoint expression levels, and drug sensitivity. In summary, we developed and validated an FRGs risk model, which served as an independent prognostic indicator for GBM. Besides, the two subgroups divided by the model have significant differences, which provides novel insights for further studies as well as the personalized treatment of patients.

ROS-Mediated Apoptosis and Anticancer Effect Achieved by Artesunate and Auxiliary Fe(II) Released from Ferriferous Oxide-Containing Recombinant Apoferritin

Reactive oxygen species (ROS)-mediated apoptosis is considered a crucial therapeutic mechanisms for artesunate (AS). As an Fe(II)-dependent drug, the anticancer effect of AS is often limited due to insufficient Fe(II) concentration in targeted cells. To overcome this problem, a recombinant apoferritin nanocarrier containing ferriferous oxide (M-HFn) is constructed to produce auxiliary exogenous Fe(II) when delivering AS to cancer cells. Here, the newly fabricated AS-loaded M-HFn nanoparticles (M-HFn@AS NPs) can significantly improve the tumor-specific targeting and intracellular uptake efficiency of AS in human cervical carcinoma cells. After being captured in the acidic cavity of endosomes, M-HFn@AS NPs can simultaneously release Fe(II) and allow AS to activate satisfactory ROS-mediated apoptosis. Furthermore, in vivo studies demonstrate that M-HFn@AS NPs can selectively accumulate in tumors to efficiently inhibit tumor growth. Thus, M-HFn@AS NPs are a promising system to enhance the therapeutic effect of Fe(II)-dependent drugs.