Anticancer effects of ikarugamycin and astemizole identified in a screen for stimulators of cellular immune responses

Chondroitin sulfate nanoparticles based on co-delivery dual drug induced ferroptosis in lung cancer cells by disrupting mitochondrial oxidative homeostasis

Mitochondrial REDOX homeostasis is unbalanced by large amounts of reactive oxygen species production and reduced glutathione, leading to lipid oxidation-induced ferroptosis, which enhanced cancer immunotherapy. Thus, disrupting mitochondrial redox homeostasis represents a promising strategy for the treatment of lung cancer. In this study, a co-delivery system of based on chondroitin sulfate (CS) (CS-CA-CUR-TPP, CCCT) for natural medicines (Curcumin, CUR; and Cinnamaldehyde CA) was successfully constructed, which resulted in elevated ROS levels in cancer cells. Under the action of CS specifically targeting tumor cells, CCCT NPs is enriched and taken up by lung cancer cells. Acid responsiveness causes the CCCT NPs to break and escape from the lysosome, and CUR targets and destroys mitochondria under the action of mitochondrial target head triphenylphosphine (TPP). CA collaborates with CUR to produce large amounts of ROS and reduce GSH in a time-dependent manner in mitochondria for disruption of REDOX homeostasis, and triggers ferroptosis by reducing the expression of GXP4 and xCT proteins. The immunogenic cell death (ICD) after ferroptosis promotes interferon γ (IFN-γ), TNF-a, and IL-6 secretion. Our results desmontrat CCCT can promote inhibition of tumor growth by enhancing tumor immunogenicity. This study may provide a potential avenue for the advancement of self-delivery nanoparticles to overcome resistance to apoptosis in tumor therapy.

Astemizole Exacerbates 5-Fluorouracil-Triggered Cardiotoxicity by Enhancing Ptgs2

5-fluorouracil (5-FU), a commonly utilized antitumor agent for the treatment of colon cancer, is linked to an increased risk of cardiovascular diseases. Antihistamines including astemizole (AST) have been reported to present cardiovascular toxicity; however, it remains unclear how 5-FU-mediated cardiotoxicity is affected by AST during the treatment of colon cancer. This study explored the role of AST in 5-FU-induced cardiotoxicity in colon cancer. 5-FU was used to induce cardiotoxicity in cardiomyocytes (HL-1 cells) and BALBc mice, creating in vitro and in vivo models of chemotherapeutic drug-induced cardiotoxicity. In the mice model, we found that the blocking of histamine signal by AST aggravated 5-FU-induced cardiac function injury and cardiac fibrosis. In HL-1 cardiomyocyte cells, the increases of apoptosis and generation of mitochondrial reactive oxygen species (mtROS) were evaluated after the combination treatment of AST and 5-FU. Proinflammatory M1-like-type macrophages were dominant in the AST and 5-FU combination group compared to control groups. The protein expression of prostaglandin-endoperoxide synthase 2 (Ptgs2) was assessed both in vitro and in vivo using Western blot analysis. Clinically, altered Ptgs2 was closely associated with adverse cardiovascular outcomes. Overall, the combination of AST and 5-FU significantly enhanced cardiotoxicity by inducing cardiomyocyte apoptosis, inflammation, and the expression of Ptgs2.

Elimination of cDC1 cells by regulatory T cells jeopardizes cancer immunotherapy

Recent findings revealed that neoantigen-specific cytotoxic type 1 regulatory T (TR1) CD4 T cells can subvert cancer immunotherapy by killing type 1 conventional dendritic cells (cDC1s) that present tumor antigens bound to MHC class II. This underlines the importance of cDC1s for eliciting anticancer immunity but poses a novel clinical challenge.

CD8+ T cell exhaustion and its regulatory mechanisms in the tumor microenvironment: key to the success of immunotherapy

A steady dysfunctional state caused by chronic antigen stimulation in the tumor microenvironment (TME) is known as CD8+ T cell exhaustion. Exhausted-like CD8+ T cells (CD8+ Tex) displayed decreased effector and proliferative capabilities, elevated co-inhibitory receptor generation, decreased cytotoxicity, and changes in metabolism and transcription. TME induces T cell exhaustion through long-term antigen stimulation, upregulation of immune checkpoints, recruitment of immunosuppressive cells, and secretion of immunosuppressive cytokines. CD8+ Tex may be both the reflection of cancer progression and the reason for poor cancer control. The successful outcome of the current cancer immunotherapies, which include immune checkpoint blockade and adoptive cell treatment, depends on CD8+ Tex. In this review, we are interested in the intercellular signaling network of immune cells interacting with CD8+ Tex. These findings provide a unique and detailed perspective, which is helpful in changing this completely unpopular state of hypofunction and intensifying the effect of immunotherapy.

Emerging role of immunogenic cell death in cancer immunotherapy: Advancing next-generation CAR-T cell immunotherapy by combination

Immunogenic cell death (ICD) is a stress-driven form of regulated cell death (RCD) in which dying tumor cells' specific signaling pathways are activated to release damage-associated molecular patterns (DAMPs), leading to the robust anti-tumor immune response as well as a reversal of the tumor immune microenvironment from "cold" to "hot". Chimeric antigen receptor (CAR)-T cell therapy, as a landmark in anti-tumor immunotherapy, plays a formidable role in hematologic malignancies but falls short in solid tumors. The Gordian knot of CAR-T cells for solid tumors includes but is not limited to, tumor antigen heterogeneity or absence, physical and immune barriers of tumors. The combination of ICD induction therapy and CAR-T cell immunotherapy is expected to promote the intensive use of CAR-T cell in solid tumors. In this review, we summarize the characteristics of ICD, stress-responsive mechanism, and the synergistic effect of various ICD-based therapies with CAR-T cells to effectively improve anti-tumor capacity.

Targeting immunogenic cell stress and death for cancer therapy

Immunogenic cell death (ICD), which results from insufficient cellular adaptation to specific stressors, occupies a central position in the development of novel anticancer treatments. Several therapeutic strategies to elicit ICD - either as standalone approaches or as means to convert immunologically cold tumours that are insensitive to immunotherapy into hot and immunotherapy-sensitive lesions - are being actively pursued. However, the development of ICD-inducing treatments is hindered by various obstacles. Some of these relate to the intrinsic complexity of cancer cell biology, whereas others arise from the use of conventional therapeutic strategies that were developed according to immune-agnostic principles. Moreover, current discovery platforms for the development of novel ICD inducers suffer from limitations that must be addressed to improve bench-to-bedside translational efforts. An improved appreciation of the conceptual difference between key factors that discriminate distinct forms of cell death will assist the design of clinically viable ICD inducers.

Immunogenic cell stress and death in the treatment of cancer

The successful treatment of oncological malignancies which results in long-term disease control or the complete eradication of cancerous cells necessitates the onset of adaptive immune responses targeting tumor-specific antigens. Such desirable anticancer immunity can be triggered via the induction of immunogenic cell death (ICD) of cancer cells, thus converting malignant cells into an in situ vaccine that elicits T cell mediated adaptive immune responses and establishes durable immunological memory. The exploration of ICD for cancer treatment has been subject to extensive research. However, functional heterogeneity among ICD activating therapies in many cases requires specific co-medications to achieve full-blown efficacy. Here, we described the hallmarks of ICD and classify ICD activators into three distinct functional categories namely, according to their mode of action: (i) ICD inducers, which increase the immunogenicity of malignant cells, (ii) ICD sensitizers, which prime cellular circuitries for ICD induction by conventional cytotoxic agents, and (iii) ICD enhancers, which improve the perception of ICD signals by antigen presenting dendritic cells. Altogether, ICD induction, sensitization and enhancement offer the possibility to convert well-established conventional anticancer therapies into immunotherapeutic approaches that activate T cell-mediated anticancer immunity.

Immunogenic cell death (ICD) enhancers-Drugs that enhance the perception of ICD by dendritic cells

The search for immunostimulatory drugs applicable to cancer immunotherapy may profit from target-agnostic methods in which agents are screened for their functional impact on immune cells cultured in vitro without any preconceived idea on their mode of action. We have built a synthetic mini-immune system in which stressed and dying cancer cells (derived from standardized cell lines) are confronted with dendritic cells (DCs, derived from immortalized precursors) and CD8+ T-cell hybridoma cells expressing a defined T-cell receptor. Using this system, we can identify three types of immunostimulatory drugs: (i) pharmacological agents that stimulate immunogenic cell death (ICD) of malignant cells; (ii) drugs that act on DCs to enhance their response to ICD; and (iii) drugs that act on T cells to increase their effector function. Here, we focus on strategies to develop drugs that enhance the perception of ICD by DCs and to which we refer as "ICD enhancers." We discuss examples of ICD enhancers, including ligands of pattern recognition receptors (exemplified by TLR3 ligands that correct the deficient function of DCs lacking FPR1) and immunometabolic modifiers (exemplified by hexokinase-2 inhibitors), as well as methods for target deconvolution applicable to the mechanistic characterization of ICD enhancers.

The BCL2 inhibitor venetoclax mediates anticancer effects through dendritic cell activation

BCL2 is an apoptosis-inhibitory oncoprotein that also possesses apoptosis-unrelated activities. Pharmacological BCL2 inhibitors have been developed with the scope of driving BCL2-dependent cancer cells into apoptosis, and one BCL2 antagonist, venetoclax, has been clinically approved for the treatment of specific leukemias and lymphomas. Nonetheless, it appears that venetoclax, as well as genetic BCL2 inhibition, can mediate anticancer effects through an indirect action. Such an indirect effect relies on the enhancement of the immunostimulatory function of dendritic cells, hence increasing tumor immunosurveillance. Mechanistically, BCL2 inhibition involves improved antigen presentation by conventional type-1 dendritic cells (cDC1s) due to the activation of an interferon response, leading to a T cell-mediated anticancer immune response that can be further enhanced by PD-1 blockade. These findings support the emerging hypothesis that successful antineoplastic drugs generally mediate their effects indirectly, through the immune system, rather via merely cell-autonomous effects on malignant cells.

Conventional type 1 dendritic cells (cDC1) in cancer immunity

Cancer immunotherapy, alone or in combination with conventional therapies, has revolutionized the landscape of antineoplastic treatments, with dendritic cells (DC) emerging as key orchestrators of anti-tumor immune responses. Among the distinct DC subsets, conventional type 1 dendritic cells (cDC1) have gained prominence due to their unique ability to cross-present antigens and activate cytotoxic T lymphocytes. This review summarizes the distinctive characteristics of cDC1, their pivotal role in anticancer immunity, and the potential applications of cDC1-based strategies in immunotherapy.

Histamine antagonists promote cancer immunosurveillance

Recently, a cellular mini-immune system comprising infinitely expandable dendritic cells and T cells led to the discovery that histamine receptor H1 antagonists act on T cells to stimulate their proliferation and polarization toward a Th1/Tc1 phenotype and to increase their anticancer activity in the context of immunochemotherapy.