Ferroptosis triggered by dihydroartemisinin facilitates chlorin e6 induced photodynamic therapy by inhibiting GPX4 and enhancing ROS

Inducing ferroptosis by traditional medicines: a novel approach to reverse chemoresistance in lung cancer

Lung cancer is the leading cause of global cancer-related deaths. Platinum-based chemotherapy is the first-line treatment for the most common type of lung cancer, i.e., non-small-cell lung cancer (NSCLC), but its therapeutic efficiency is limited by chemotherapeutic resistance. Therefore, it is vital to develop effective therapeutic modalities that bypass the common molecular mechanisms associated with chemotherapeutic resistance. Ferroptosis is a form of non-apoptotic regulated cell death characterized by iron-dependent lipid peroxidation (LPO). Ferroptosis is crucial for the proper therapeutic efficacy of lung cancer-associated chemotherapies. If targeted as a novel therapeutic mechanism, ferroptosis modulators present new opportunities for increasing the therapeutic efficacy of lung cancer chemotherapy. Emerging studies have revealed that the pharmacological induction of ferroptosis using natural compounds boosts the efficacy of chemotherapy in lung cancer or drug-resistant cancer. In this review, we first discuss chemotherapeutic resistance (or chemoresistance) in lung cancer and introduce the core mechanisms behind ferroptosis. Then, we comprehensively summarize the small-molecule compounds sourced from traditional medicines that may boost the anti-tumor activity of current chemotherapeutic agents and overcome chemotherapeutic resistance in NSCLC. Cumulatively, we suggest that traditional medicines with ferroptosis-related anticancer activity could serve as a starting point to overcome chemotherapeutic resistance in NSCLC by inducing ferroptosis, highlighting new potential therapeutic regimens used to overcome chemoresistance in NSCLC.

Dihydroartemisinin-driven selective anti-lung cancer proliferation by binding to EGFR and inhibition of NRAS signaling pathway-induced DNA damage

Chemotherapeutic agents can inhibit the proliferation of malignant cells due to their cytotoxicity, which is limited by collateral damage. Dihydroartemisinin (DHA), has a selective anti-cancer effect, whose target and mechanism remain uncovered. The present work aims to examine the selective inhibitory effect of DHA as well as the mechanisms involved. The findings revealed that the Lewis cell line (LLC) and A549 cell line (A549) had an extremely rapid proliferation rate compared with the 16HBE cell line (16HBE). LLC and A549 showed an increased expression of NRAS compared with 16HBE. Interestingly, DHA was found to inhibit the proliferation and facilitate the apoptosis of LLC and A549 with significant anti-cancer efficacy and down-regulation of NRAS. Results from molecular docking and cellular thermal shift assay revealed that DHA could bind to epidermal growth factor receptor (EGFR) molecules, attenuating the EGF binding and thus driving the suppressive effect. LLC and A549 also exhibited obvious DNA damage in response to DHA. Further results demonstrated that over-expression of NRAS abated DHA-induced blockage of NRAS. Moreover, not only the DNA damage was impaired, but the proliferation of lung cancer cells was also revitalized while NRAS was over-expression. Taken together, DHA could induce selective anti-lung cancer efficacy through binding to EGFR and thereby abolishing the NRAS signaling pathway, thus leading to DNA damage, which provides a novel theoretical basis for phytomedicine molecular therapy of malignant tumors.

Dihydroartemisinin-driven TOM70 inhibition leads to mitochondrial destabilization to induce pyroptosis against lung cancer

Enhancement of malignant cell immunogenicity to relieve immunosuppression of lung cancer microenvironment is essential in lung cancer treatment. In previous study, we have demonstrated that dihydroartemisinin (DHA), a kind of phytopharmaceutical, is effective in inhibiting lung cancer cells and boosting their immunogenicity, while the initial target of DHA's intracellular action is poorly understood. The present in-depth analysis aims to reveal the influence of DHA on the highly expressed TOM70 in the mitochondrial membrane of lung cancer. The affinity of DHA and TOM70 was analyzed by microscale thermophoresis (MST), pronase stability, and thermal stability. The functions and underlying mechanism were investigated using western blots, qRT-PCR, flow cytometry, and rescue experiments. TOM70 inhibition resulted in mtDNA damage and translocation to the cytoplasm from mitochondria due to the disruption of mitochondrial homeostasis. Further ex and in vivo findings also showed that the cGAS/STING/NLRP3 signaling pathway was activated by mtDNA and thereby malignant cells underwent pyroptosis, leading to enhanced immunogenicity of lung cancer cells in the presence of DHA. Nevertheless, DHA-induced mtDNA translocation and cGAS/STING/NLRP3 mobilization were synchronously attenuated when TOM70 was replenished. Finally, DHA was demonstrated to possess potent anti-lung cancer efficacy in vitro and in vivo. Taken together, these data confirm that TOM70 is an important target for DHA to disturb mitochondria homeostasis, which further activates STING and arouses pyroptosis to strengthen immunogenicity against lung cancer thereupon. The present study provides vital clues for phytomedicine-mediated anti-tumor therapy.

Tumor-associated macrophages affect the treatment of lung cancer

As one of the most common malignant tumors in the world, lung cancer has limited benefits for patients despite its diverse treatment methods due to factors such as personalized medicine targeting histological type, immune checkpoint expression, and driver gene mutations. The high mortality rate of lung cancer is partly due to the immune-suppressive which limits the effectiveness of anti-cancer drugs and induces tumor cell resistance. The currently widely recognized TAM phenotypes include the anti-tumor M1 and pro-tumor M2 phenotypes. M2 macrophages promote the formation of an immune-suppressive microenvironment and hinder immune cell infiltration, thereby inhibiting activation of the anti-tumor immune system and aiding tumor cells in resisting treatment. Analyzing the relationship between different treatment methods and macrophages in the TME can help us better understand the impact of TAMs on lung cancer and confirm the feasibility of targeted TAM therapy. Targeting TAMs to reduce the M2/M1 ratio and reverse the immune-suppressive microenvironment can improve the clinical efficacy of conventional treatment methods and potentially open up more efficient combination treatment strategies, maximizing the benefit for lung cancer patients.

Ferroptosis in lung cancer: dual role, multi-level regulation, and new therapeutic strategies

Lung cancer is a highly prevalent malignant tumor worldwide, with high incidence and death rates. Recently, there has been increasing recognition of the role of ferroptosis, a unique cell death mechanism, in lung cancer. This review aims to summarize the current research progress on the relationship between ferroptosis and lung cancer. It also provides a comprehensive analysis of the regulatory processes of ferroptosis in various stages, including epigenetics, transcription, post-transcription, translation, and post-translation. Additionally, the review explores the dual nature of ferroptosis in lung cancer progression, which presents interesting therapeutic possibilities. On one hand, ferroptosis can promote the escape of immune surveillance and reduce the efficacy of treatment in the early stages of tumors. On the other hand, it can counter drug resistance, enhance radiosensitivity, and promote immunotherapy. The article also discusses various combination treatment strategies based on the mechanism of ferroptosis. Overall, this review offers a holistic perspective on the role of ferroptosis in the onset, progression, and treatment of lung cancer. It aims to contribute to future research and clinical interventions in this field.

Combining near infrared fluorescence and laser speckle imaging with optical tissue clearing for in vivo transcranial monitoring of cerebral blood vessels damaged by photodynamic nanoformulation

In vivo near infrared (NIR) fluorescence imaging and laser speckle contrast imaging (LSCI) are emerging optical bioimaging modalities, which can provide information on blood vessels morphology, volume and the blood flow velocity. Optical tissue clearing (OTC) technique addresses a light scattering problem in optical bioimaging, which is imperative for the transcranial brain imaging. Herein, we report an approach combining NIR fluorescence and LSC microscopy imaging with OTC. A liposomal nanoformulation comprising NIR fluorescent dye ICG and photosensitizer BPD was synthesized and injected intravenously into mouse with OTC treated skull. Transcranial excitation of BPD in nanoliposomes resulted in the localized, irradiation dose dependent photodynamic damage of the brain blood vessels, which was manifested both in NIR fluorescence and LSC transcranial imaging, revealing changes in the vessels morphology, volume and the blood flow rate. The developed approach allows for bimodal imaging guided, localized vascular PDT of cancer and other diseases.

Effects of Natural Products on Enzymes Involved in Ferroptosis: Regulation and Implications

Ferroptosis is a form of regulated cell death that is characterized by the accumulation of iron-dependent lipid peroxides. The regulation of ferroptosis involves both non-enzymatic reactions and enzymatic mechanisms. Natural products have demonstrated potential effects on various enzymes, including GPX4, HO-1, NQO1, NOX4, GCLC, and GCLM, which are mainly involved in glutathione metabolic pathway or oxidative stress regulation, and ACSL3 and ACSL4, which mainly participate in lipid metabolism, thereby influencing the regulation of ferroptosis. In this review, we have provided a comprehensive overview of the existing literature pertaining to the effects of natural products on enzymes involved in ferroptosis and discussed their potential implications for the prevention and treatment of ferroptosis-related diseases. We also highlight the potential challenge that the majority of research has concentrated on investigating the impact of natural products on the expression of enzymes involving ferroptosis while limited attention is given to the regulation of enzyme activity. This observation underscores the considerable potential and scope for exploring the influence of natural products on enzyme activity.

Drug Repurposing-Based Brain-Targeting Self-Assembly Nanoplatform Using Enhanced Ferroptosis against Glioblastoma

Glioblastoma (GBM), the most aggressive and lethal form of malignant brain tumor, is a therapeutic challenge due to the drug filtration capabilities of the blood-brain barrier (BBB). Interestingly, glioblastoma tends to resist apoptosis during chemotherapy, but is susceptible to ferroptosis. Developing therapies that can effectively target glioblastoma by crossing the BBB and evoke ferroptosis are, therefore, crucial for improving treatment outcomes. Herein, a versatile biomimetic nanoplatform, L-D-I/NPs, is designed that self-assembled by loading the antimalarial drug dihydroartemisinin (DHA) and the photosensitizer indocyanine green (ICG) onto lactoferrin (LF). This nanoplatform can selectively target glioblastoma by binding to low-density lipoprotein receptor-related protein-1 (LRP1) and crossing the BBB, thus inducing glioblastoma cell ferroptosis by boosting intracellular reactive oxygen species (ROS) accumulation and iron overload. In addition, L-D-I/NPs have demonstrated the ability to effectively suppress the progression of orthotopic glioblastoma and significantly prolong survival in a mouse glioblastoma model. This nanoplatform has facilitated the application of non-chemotherapeutic drugs in tumor treatment with minimal adverse effects, paving the way for highly efficient ferroptosis-based therapies for glioblastoma.

A Dihydroartemisinin-Loaded Nanoreactor Motivates Anti-Cancer Immunotherapy by Synergy-Induced Ferroptosis to Activate Cgas/STING for Reprogramming of Macrophage

Infiltration of tumor-associated macrophages (TAM) characterized by an M2 phenotype is an overriding feature in malignant tumors. Reprogramming TAM is the most cutting-edge strategy for cancer therapy. In the present study, an iron-based metal-organic framework (MOF) nanoreactor loaded with dihydroartemisinin (DHA) is developed, which provides high uptake by TAM and retains their viability, thus effectively addressing the inefficiency of the DHA at low concentrations. Impressively, DHA@MIL-101 can selectively accumulate in tumor tissues and remodel TAM to the M1 phenotype. The results of RNA sequencing further suggest that this nanoreactor may regulate ferroptosis, a DNA damage signaling pathway in TAM. Indeed, the outcomes confirm that DHA@MIL-101 triggers ferroptosis in TAM. In addition, the findings reveal that DNA damage induced by DHA nanoreactors activates the intracellular cGAS sensor, resulting in the binding of STING to IRF3 and thereby up-regulating the immunogenicity. In contrast, blocking ferroptosis impairs DHA@MIL-101-induced activation of STING signaling and phenotypic remodeling. Finally, it is shown that DHA nanoreactors deploy anti-tumor immunotherapy through ferroptosis-mediated TAM reprogramming. Taken together, immune efficacy is achieved through TAM's remodeling by delivering DHA and iron ions into TAM using nanoreactors, providing a novel approach for combining phytopharmaceuticals with nanocarriers to regulate the immune microenvironment.

Photodynamic Therapy Combined with Ferroptosis Is a Synergistic Antitumor Therapy Strategy

Ferroptosis is a programmed death mode that regulates redox homeostasis in cells, and recent studies suggest that it is a promising mode of tumor cell death. Ferroptosis is regulated by iron metabolism, lipid metabolism, and intracellular reducing substances, which is the mechanism basis of its combination with photodynamic therapy (PDT). PDT generates reactive oxygen species (ROS) and 1O2 through type I and type II photochemical reactions, and subsequently induces ferroptosis through the Fenton reaction and the peroxidation of cell membrane lipids. PDT kills tumor cells by generating excessive cytotoxic ROS. Due to the limited laser depth and photosensitizer enrichment, the systemic treatment effect of PDT is not good. Combining PDT with ferroptosis can compensate for these shortcomings. Nanoparticles constructed by photosensitizers and ferroptosis agonists are widely used in the field of combination therapy, and their targeting and biological safety can be improved through modification. These nanoparticles not only directly kill tumor cells but also further exert the synergistic effect of PDT and ferroptosis by activating antitumor immunity, improving the hypoxia microenvironment, and inhibiting the tumor angiogenesis. Ferroptosis-agonist-induced chemotherapy and PDT-induced ablation also have good clinical application prospects. In this review, we summarize the current research progress on PDT and ferroptosis and how PDT and ferroptosis promote each other.

ART714 is a best-in-class antileukemic 2-carbon-linked dimeric artemisinin derivative

PURPOSE

It has become increasingly clear that new multiagent combination regimens are required to improve survival rates in acute myeloid leukemia (AML). We recently reported that ART631, a first-in-class 2-carbon-linked artemisinin-derived dimer (2C-ART), was not only efficacious as a component of a novel three-drug combination regimen to treat AML, but, like other synthetic artemisinin derivatives, demonstrated low clinical toxicity. However, we ultimately found ART631 to have suboptimal solubility and stability properties, thus limiting its potential for clinical development.

METHODS

We assessed 22 additional 2C-ARTs with documented in vivo antimalarial activity for antileukemic efficacy and physicochemical properties. Our strategy involved culling out 2C-ARTs inferior to ART631 with respect to potency, stability, and solubility in vitro, and then validating in vivo pharmacokinetics, pharmacodynamics, and efficacy of one 2C-ART lead compound.

RESULTS

Of the 22 2C-ARTs, ART714 was found to have the most optimal in vitro solubility, stability, and antileukemic efficacy, both alone and in combination with the BCL2 inhibitor venetoclax (VEN) and the kinase inhibitor sorafenib (SOR). ART714 was also highly effective in combination with VEN and the FMS-like tyrosine kinase 3 inhibitor gilteritinib (GILT) against MOLM14 AML xenografts.

CONCLUSION

We identified ART714 as our best-in-class antileukemic 2C-ART, based on in vitro potency and pharmacologic properties. We established its in vivo pharmacokinetics and demonstrated its in vitro cooperativity with VEN and SOR and in vivo activities of combinations of ART714, VEN, and GILT. Additional research is indicated to define the optimal niche for the use of ART714 in treatment of AML.

Nanoparticle-mediated synergistic anticancer effect of ferroptosis and photodynamic therapy: Novel insights and perspectives

Current antitumor monotherapy has many limitations, highlighting the need for novel synergistic anticancer strategies. Ferroptosis is an iron-dependent form of nonapoptotic cell death that plays a pivotal regulatory role in tumorigenesis and treatment. Photodynamic therapy (PDT) causes irreversible chemical damage to target lesions and is widely used in antitumor therapy. However, PDT's effectiveness is usually hindered by several obstacles, such as hypoxia, excess glutathione (GSH), and tumor resistance. Ferroptosis improves the anticancer efficacy of PDT by increasing oxygen and reactive oxygen species (ROS) or reducing GSH levels, and PDT also enhances ferroptosis induction due to the ROS effect in the tumor microenvironment (TME). Strategies based on nanoparticles (NPs) can subtly exploit the potential synergy of ferroptosis and PDT. This review explores recent advances and current challenges in the landscape of the underlying mechanisms regulating ferroptosis and PDT, as well as nano delivery system-mediated synergistic anticancer activity. These include polymers, biomimetic materials, metal organic frameworks (MOFs), inorganics, and carrier-free NPs. Finally, we highlight future perspectives of this novel emerging paradigm in targeted cancer therapies.

Up-regulation of ABCG2 by MYBL2 deletion drives Chlorin e6-mediated photodynamic therapy resistance in colorectal cancer

OBJECTIVE

Photodynamic therapy (PDT) is an effective therapeutic strategy for colorectal cancer at an early stage. However, malignant cells' resistance to photodynamic agents can lead to treatment failure. MYBL2 (B-Myb) is an oncogene in colorectal carcinogenesis and development, for which little research has focused on its effect on drug resistance.

MATERIALS AND METHODS

In the present work, a colorectal cancer cell line with a stable knockdown of MYBL2 (ShB-Myb) was constructed first. Chlorin e6 (Ce6) was utilized to induced PDT. The anti-cancer efficacy was measured by CCK-8, PI staining, and Western blots. The drug uptake of Ce6 was assayed by flow cytometry and confocal microscopy. The ROS generation was detected by the CellROX probe. DDSB and DNA damage were assayed through comet experiment and Western blots. The over-expression of MYBL2 was conducted by MYBL2 plasmid.

RESULTS

The findings indicated that the viability of ShB-Myb treated with Ce6-PDT was not decreased compared to control SW480 cells (ShNC), which were resistant to PDT. Further investigation revealed reduced photosensitizer enrichment and mitigated oxidative DNA damage in colorectal cancer cells with depressed MYBL2. It turned out that SW480 cells knocking down MYBL2 showed phosphorylation of NF-κB and led to up-regulation of ABCG2 expression thereupon. When MYBL2 was replenished back in MYBL2-deficient colorectal cancer cells, phosphorylation of NF-κB was blocked and ABCG2 expression up-regulation was suppressed. Additionally, replenishment of MYBL2 also increased the enrichment of Ce6 and the efficacy of PDT.

CONCLUSION

In summary, MYBL2 absence in colorectal cancer contributes to drug resistance by activating NF-κB to up-regulate ABCG2 and thereby leading to photosensitizer Ce6 efflux. This study provides a novel theoretical basis and strategy for how to effectively improve the anti-tumor efficacy of PDT.

Ferroptosis in lung cancer: a novel pathway regulating cell death and a promising target for drug therapy

Lung cancer is a common malignant tumor that occurs in the human body and poses a serious threat to human health and quality of life. The existing treatment methods mainly include surgical treatment, chemotherapy, and radiotherapy. However, due to the strong metastatic characteristics of lung cancer and the emergence of related drug resistance and radiation resistance, the overall survival rate of lung cancer patients is not ideal. There is an urgent need to develop new treatment strategies or new effective drugs to treat lung cancer. Ferroptosis, a novel type of programmed cell death, is different from the traditional cell death pathways such as apoptosis, necrosis, pyroptosis and so on. It is caused by the increase of iron-dependent reactive oxygen species due to intracellular iron overload, which leads to the accumulation of lipid peroxides, thus inducing cell membrane oxidative damage, affecting the normal life process of cells, and finally promoting the process of ferroptosis. The regulation of ferroptosis is closely related to the normal physiological process of cells, and it involves iron metabolism, lipid metabolism, and the balance between oxygen-free radical reaction and lipid peroxidation. A large number of studies have confirmed that ferroptosis is a result of the combined action of the cellular oxidation/antioxidant system and cell membrane damage/repair, which has great potential application in tumor therapy. Therefore, this review aims to explore potential therapeutic targets for ferroptosis in lung cancer by clarifying the regulatory pathway of ferroptosis. Based on the study of ferroptosis, the regulation mechanism of ferroptosis in lung cancer was understood and the existing chemical drugs and natural compounds targeting ferroptosis in lung cancer were summarized, with the aim of providing new ideas for the treatment of lung cancer. In addition, it also provides the basis for the discovery and clinical application of chemical drugs and natural compounds targeting ferroptosis to effectively treat lung cancer.

Dihydroartemisinin elicits immunogenic death through ferroptosis-triggered ER stress and DNA damage for lung cancer immunotherapy

BACKGROUND

The immunosuppressive microenvironment of lung cancer serves as an important endogenous contributor to treatment failure. The present study aimed to demonstrate the promotive effect of DHA on immunogenic cell death (ICD) in lung cancer as well as the mechanism.

METHODS

The lewis lung cancer cells (LLC), A549 cells and LLC-bearing mice were applied as the lung cancer model. The apoptosis, ferroptosis assay, western blotting, immunofluorescent staining, qPCR, comet assay, flow cytometry, confocal microscopy, transmission electron microscopy and immunohistochemistry were conducted to analyze the functions and the underlying mechanism.

RESULTS

An increased apoptosis rate and immunogenicity were detected in DHA-treated LLC and tumor grafts. Further findings showed DHA caused lipid peroxide (LPO) accumulation, thereby initiating ferroptosis. DHA stimulated cellular endoplasmic reticulum (ER) stress and DNA damage simultaneously. However, the ER stress and DNA damage induced by DHA could be abolished by ferroptosis inhibitors, whose immunogenicity enhancement was synchronously attenuated. In contrast, the addition of exogenous iron ions further improved the immunogenicity induced by DHA accompanied by enhanced ER stress and DNA damage. The enhanced immunogenicity could be abated by ER stress and DNA damage inhibitors as well. Finally, DHA activated immunocytes and exhibited excellent anti-cancer efficacy in LLC-bearing mice.

CONCLUSIONS

In summary, the current study demonstrates that DHA triggers ferroptosis, facilitating the ICD of lung cancer thereupon. This work reveals for the first time the effect and underlying mechanism by which DHA induces ICD of cancer cells, providing novel insights into the regulation of the immune microenvironment for cancer immunotherapy by Chinese medicine phytopharmaceuticals.

A novel chlorin e6 derivative-mediated photodynamic therapy STBF-PDT reverses photoaging via the TGF-β pathway

OBJECTIVE

Photoaging is characterized by wrinkles in the skin and the deterioration of the skin barrier function, mainly caused by long-term exposure to ultraviolet (UV) radiation. Photodynamic therapy (PDT) has been shown to treat photoaging. The novel photosensitizer ShengTaiBuFen(STBF) is a derived substance of Chlorin e6(Ce6) that can exert photodynamic effects directly. In this study, we investigated the availability and the mechanism of STBF-PDT in the treatment of photoaging.

METHODS

Fluorophotometer was used to determine therapeutic parameters for in vivo experiments. Camera photographs, dermoscopy, HE and Masson staining, skin pH, trans epidermal water loss (TEWL), epidermal water content, and sebum testing were used together to evaluate the results of the treatment. Dark toxicity and therapeutic parameters for in vitro experiments were determined by CCK8 analysis. Scratch assay was used to identify the cell migration of STBF-PDT on HaCaT cells. qPCR and Western blot were used to evaluate the TGF-β/Smad signaling pathway in human dermal fibroblast (HDF) cells.

RESULTS

We investigated the optimal STBF concentration and time of incubation in vivo and in vitro experiments. STBF-PDT improved the skin phenotype of photoaged mice. The skin of photoaged mice treated with 80 J/cm² STBF-PDT became smooth, while skin flakes were reduced. The epidermis of STBF-PDT-treated mice was thinner, and the cells were neatly arranged, with increased dermal collagen. In vitro, STBF-PDT promoted the migration of HaCaT cells below a light dose of 0.1 J/cm². HDF cells co-cultured with HaCaT cells treated with low-dose STBF-PDT showed activation of the TGF-β pathway.

CONCLUSION

As a novel photosensitizer, STBF-mediated low-dose PDT could reverse photoaging via the TGF-β pathway.

Chlorin e6-induced photodynamic effect facilitates immunogenic cell death of lung cancer as a result of oxidative endoplasmic reticulum stress and DNA damage

Suppression of the immune microenvironment is an important endogenous contributor to treatment failure in lung cancer. Photodynamic therapy (PDT) is widely used in the treatment of malignant tumors owing to its photo-selectivity and minimal side effects. Some studies have shown the ability of photodynamic action not only to cause photo-cytotoxicity to tumor cells but also to induce immunogenic cell death (ICD). However, the mechanism by which PDT enhances tumor immunogenicity is poorly understood. The present study aimed to explore the immunogenicity effect of PDT on lung cancer and to reveal the underlying mechanism. First, we searched for effective conditions for PDT-induced apoptosis in lung cancer cells. Just as expected, chlorin e6 (Ce6) PDT could enhance the immunogenicity of lung cancer cells alongside the induction of apoptosis, characterized by up-regulation of CRT, HSP90, HMGB1 and MHC-I. Further results showed the generation of ROS by Ce6 PDT under the above conditions, which is an oxidative damaging agent. Simultaneously, PDT induced endoplasmic reticulum (ER) stress in cells, as evidenced by enhanced Tht staining and up-regulated CHOP and GRP78 expression. Moreover, PDT led to DNA damage response (DDR) as well. However, the redox inhibitor NAC abolished the ER stress and DDR caused by PDT. More importantly, NAC also attenuated PDT-induced improvement of immunogenicity in lung cancer. On this basis, the PDT-induced CRT up-regulation was found to be attenuated in response to inhibition of ER stress. In addition, PDT-induced increase in HMGB1 and HSP90 release was blocked by inhibition of DDR. In summary, Ce6 PDT could produce ROS under certain conditions, which leads to ER stress that promotes CRT translocation to the cell membrane, and the resulting DNA damage causes the expression and release of nuclear HMGB1 and HSP90, thereby enhancing the immunogenicity of lung cancer. This current study elucidates the mechanism of PDT in ameliorating the immunogenicity of lung cancer, providing a rationale for PDT in regulating the immune microenvironment for the treatment of malignant tumors.

Overcoming cancer chemotherapy resistance by the induction of ferroptosis

Development of resistance to chemotherapy in cancer continues to be a major challenge in cancer management. Ferroptosis, a unique type of cell death, is mechanistically and morphologically different from other forms of cell death. Ferroptosis plays a pivotal role in inhibiting tumour growth and has presented new opportunities for treatment of chemotherapy-insensitive tumours in recent years. Emerging studies have suggested that ferroptosis can regulate the therapeutic responses of tumours. Accumulating evidence supports ferroptosis as a potential target for chemotherapy resistance. Pharmacological induction of ferroptosis could reverse drug resistance in tumours. In this review article, we first discuss the key principles of chemotherapeutic resistance in cancer. We then provide a brief overview of the core mechanisms of ferroptosis in cancer chemotherapeutic drug resistance. Finally, we summarise the emerging data that supports the fact that chemotherapy resistance in different types of cancers could be subdued by pharmacologically inducing ferroptosis. This review article suggests that pharmacological induction of ferroptosis by bioactive compounds (ferroptosis inducers) could overcome chemotherapeutic drug resistance. This article also highlights some promising therapeutic avenues that could be used to overcome chemotherapeutic drug resistance in cancer.

Antibody-modified Gold Nanobiostructures: Advancing Targeted Photodynamic Therapy for Improved Cancer Treatment

Photodynamic therapy (PDT) is an innovative, non-invasive method of treating cancer that uses light-activated photosensitizers to create reactive oxygen species (ROS). However, challenges associated with the limited penetration depth of light and the need for precise control over photosensitizer activation have hindered its clinical translation. Nanomedicine, particularly gold nanobiostructures, offers promising solutions to overcome these limitations. This paper reviews the advancements in PDT and nanomedicine, focusing on applying antibody-modified gold nanobiostructures as multifunctional platforms for enhanced PDT efficacy and improved cancer treatment outcomes. The size, shape, and composition of gold nanobiostructures can significantly influence their PDT efficacy, making synthetic procedures crucial. Functionalizing the surface of gold nanobiostructures with various molecules, such as antibodies or targeting agents, bonding agents, PDT agents, photothermal therapy (PTT) agents, chemo-agents, immunotherapy agents, and imaging agents, allows composition modification. Integrating gold nanobiostructures with PDT holds immense potential for targeted cancer therapy. Antibody-modified gold nanobiostructures, in particular, have gained significant attention due to their tunable plasmonic characteristics, biocompatibility, and surface functionalization capabilities. These multifunctional nanosystems possess unique properties that enhance the efficacy of PDT, including improved light absorption, targeted delivery, and enhanced ROS generation. Passive and active targeting of gold nanobiostructures can enhance their localization near cancer cells, leading to efficient eradication of tumor tissues upon light irradiation. Future research and clinical studies will continue to explore the potential of gold nanobiostructures in PDT for personalized and effective cancer therapy. The synthesis, functionalization, and characterization of gold nanobiostructures, their interaction with light, and their impact on photosensitizers' photophysical and photochemical properties, are important areas of investigation. Strategies to enhance targeting efficiency and the evaluation of gold nanobiostructures in vitro and in vivo studies will further advance their application in PDT. The integrating antibody-modified gold nanobiostructures in PDT represents a promising strategy for targeted cancer therapy. These multifunctional nanosystems possess unique properties that enhance PDT efficacy, including improved light absorption, targeted delivery, and enhanced ROS generation. Continued research and development in this field will contribute to the advancement of personalized and effective cancer treatment approaches.

Ferroptosis-based drug delivery system as a new therapeutic opportunity for brain tumors

The brain tumor is a kind of malignant tumor with brutal treatment, high recurrence rate, and poor prognosis, and the incidence and death rate is increasing yearly. Surgery is often used to remove the primary tumor, supplemented by radiotherapy and chemotherapy, which have highly toxic side effects. Therefore, there is an urgent need to explore new strategies, methods, and technologies that can genuinely improve the treatment of brain tumors. Ferroptosis differs from traditional apoptosis's morphological and biochemical characteristics, and ferroptosis possesses its unique characteristics and mechanisms, opening up a new field of ferroptosis treatment for cancer. It has been found that there is a close relationship between ferroptosis and brain tumors, and a novel nano-drug delivery system based on ferroptosis has been used for the ferroptosis treatment of brain tumors with remarkable effects. This review firstly analyzes the characteristics of ferroptosis, summarizes the mechanism of its occurrence and some factors that can be involved in the regulation of ferroptosis, introduces the potential link between ferroptosis and brain tumors, and clarifies the feasibility of ferroptosis in the treatment of brain tumors. It then presents the ferroptosis nano drug delivery systems developed under different metabolic pathways for ferroptosis treatment of brain tumors. Finally, it summarizes the current problems and solutions of ferroptosis nano drugs for brain tumor treatment, aiming to provide a reference for developing ferroptosis nano drugs against brain tumors.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

System Xc−/GSH/GPX4 axis: An important antioxidant system for the ferroptosis in drug-resistant solid tumor therapy

The activation of ferroptosis is a new effective way to treat drug-resistant solid tumors. Ferroptosis is an iron-mediated form of cell death caused by the accumulation of lipid peroxides. The intracellular imbalance between oxidant and antioxidant due to the abnormal expression of multiple redox active enzymes will promote the produce of reactive oxygen species (ROS). So far, a few pathways and regulators have been discovered to regulate ferroptosis. In particular, the cystine/glutamate antiporter (System Xc−), glutathione peroxidase 4 (GPX4) and glutathione (GSH) (System Xc−/GSH/GPX4 axis) plays a key role in preventing lipid peroxidation-mediated ferroptosis, because of which could be inhibited by blocking System Xc−/GSH/GPX4 axis. This review aims to present the current understanding of the mechanism of ferroptosis based on the System Xc−/GSH/GPX4 axis in the treatment of drug-resistant solid tumors.

Dihydroartemisinin remodels macrophage into an M1 phenotype via ferroptosis-mediated DNA damage

Lung cancer recruits tumor-associated macrophages (TAMs) massively, whose predominantly pro-tumor M2 phenotype leads to immunosuppression. Dihydroartemisinin (DHA) has been proven to remodel TAM into an anti-tumor M1 phenotype at certain concentrations in the present study, which was hypothesized to facilitate anti-lung cancer immunotherapy. However, how DHA remodels the TAM phenotype has not yet been uncovered. Our previous work revealed that DHA could trigger ferroptosis in lung cancer cells, which may also be observed in TAM thereupon. Sequentially, in the current study, DHA was found to remodel TAM into the M1 phenotype in vitro and in vivo. Simultaneously, DHA was observed to trigger ferroptosis in TAM and cause the DNA damage response and NF-κB activation. Conversely, the DHA-induced DNA damage response and NF-κB activation in TAM were attenuated after the inhibition of ferroptosis in TAM using an inhibitor of ferroptosis. Importantly, a ferroptosis inhibitor could also abolish the DHA-induced phenotypic remodeling of TAM toward the M1 phenotype. In a nutshell, this work demonstrates that DHA-triggered ferroptosis of TAM results in DNA damage, which could activate downstream NF-κB to remodel TAM into an M1 phenotype, providing a novel strategy for anti-lung cancer immunotherapy. This study offers a novel strategy and theoretical basis for the use of traditional Chinese medicine monomers to regulate the anti-tumor immune response, as well as a new therapeutic target for TAM phenotype remodeling.

Discovery of 1,3,4-oxadiazole derivatives containing a bisamide moiety as a novel class of potential cardioprotective agents

Myocardial injury is a nonnegligible problem in cardiovascular diseases and cancer therapy. The functional feature of N-containing heterocycles in the cardiovascular field has attracted much attention in recent years. Herein, we discovered a lead compound 12a containing 1,3,4-oxadiazole by extensive screening of anticancer derivatives containing nitrogen-heterocycle, which exhibited potential protective activity against oxidative stress in cardiomyocytes. Follow-up structure-activity relationship (SAR) studies also highlighted the role of substitution sites and bisamide moiety in enhancing the protective activity against oxidative stress. Specifically, compound 12d exhibited low cytotoxicity under high concentration and potent myocardial protection against oxidative stress in H9c2 cells. Preliminary mechanistic studies showed compound 12d could decrease the expression of cardiac hypertrophy and oxidative stress-related proteins/genes and reduce mitochondria-mediated cell apoptosis, thereby enhancing the cell vitality of injured cardiomyocytes. In this study, 1,3,4-oxadiazole may represent a novel pharmacophore that possesses potential myocardial protection and provides more choices for future optimization of cardiovascular drugs, especially for the treatment of onco-cardiology.

A nanoreactor boosts chemodynamic therapy and ferroptosis for synergistic cancer therapy using molecular amplifier dihydroartemisinin

Background

Chemodynamic therapy (CDT) relying on intracellular iron ions and H₂O₂ is a promising therapeutic strategy due to its tumor selectivity, which is limited by the not enough metal ions or H₂O₂ supply of tumor microenvironment. Herein, we presented an efficient CDT strategy based on Chinese herbal monomer-dihydroartemisinin (DHA) as a substitute for the H₂O₂ and recruiter of iron ions to amplify greatly the reactive oxygen species (ROS) generation for synergetic CDT-ferroptosis therapy.

Results

The DHA@MIL-101 nanoreactor was prepared and characterized firstly. This nanoreactor degraded under the acid tumor microenvironment, thereby releasing DHA and iron ions. Subsequent experiments demonstrated DHA@MIL-101 significantly increased intracellular iron ions through collapsed nanoreactor and recruitment effect of DHA, further generating ROS thereupon. Meanwhile, ROS production introduced ferroptosis by depleting glutathione (GSH), inactivating glutathione peroxidase 4 (GPX4), leading to lipid peroxide (LPO) accumulation. Furthermore, DHA also acted as an efficient ferroptosis molecular amplifier by direct inhibiting GPX4. The resulting ROS and LPO caused DNA and mitochondria damage to induce apoptosis of malignant cells. Finally, in vivo outcomes evidenced that DHA@MIL-101 nanoreactor exhibited prominent anti-cancer efficacy with minimal systemic toxicity.

Conclusion

In summary, DHA@MIL-101 nanoreactor boosts CDT and ferroptosis for synergistic cancer therapy by molecular amplifier DHA. This work provides a novel and effective approach for synergistic CDT-ferroptosis with Chinese herbal monomer-DHA and Nanomedicine.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01455-0.