Crizotinib-induced immunogenic cell death in non-small cell lung cancer

In Situ Cancer Vaccines: Redefining Immune Activation in the Tumor Microenvironment

Cancer is one of the leading causes of mortality worldwide. Nanomedicines have significantly improved life expectancy and survival rates for cancer patients in current standard care. However, recurrence of cancer due to metastasis remains a significant challenge. Vaccines can provide long-term protection and are ideal for preventing bacterial and viral infections. Cancer vaccines, however, have shown limited therapeutic efficacy and raised safety concerns despite extensive research. Cancer vaccines target and stimulate responses against tumor-specific antigens and have demonstrated great potential for cancer treatment in preclinical studies. However, tumor-associated immunosuppression and immune tolerance driven by immunoediting pose significant challenges for vaccine design. In situ vaccination represents an alternative approach to traditional cancer vaccines. This strategy involves the intratumoral administration of immunostimulants to modulate the growth and differentiation of innate immune cells, such as dendritic cells, macrophages, and neutrophils, and restore T-cell activity. Currently approved in situ vaccines, such as T-VEC, have demonstrated clinical promise, while ongoing clinical trials continue to explore novel strategies for broader efficacy. Despite these advancements, failures in vaccine research highlight the need to address tumor-associated immune suppression and immune escape mechanisms. In situ vaccination strategies combine innate and adaptive immune stimulation, leveraging tumor-associated antigens to activate dendritic cells and cross-prime CD8+ T cells. Various vaccine modalities, such as nucleotide-based vaccines (e.g., RNA and DNA vaccines), peptide-based vaccines, and cell-based vaccines (including dendritic, T-cell, and B-cell approaches), show significant potential. Plant-based viral approaches, including cowpea mosaic virus and Newcastle disease virus, further expand the toolkit for in situ vaccination. Therapeutic modalities such as chemotherapy, radiation, photodynamic therapy, photothermal therapy, and Checkpoint blockade inhibitors contribute to enhanced antigen presentation and immune activation. Adjuvants like CpG-ODN and PRR agonists further enhance immune modulation and vaccine efficacy. The advantages of in situ vaccination include patient specificity, personalization, minimized antigen immune escape, and reduced logistical costs. However, significant barriers such as tumor heterogeneity, immune evasion, and logistical challenges remain. This review explores strategies for developing potent cancer vaccines, examines ongoing clinical trials, evaluates immune stimulation methods, and discusses prospects for advancing in situ cancer vaccination.

Endoplasmic Reticulum-Targeted Photodynamic Therapy Combined with Autophagy Inhibition to Enhance Synergistic Immunotherapy for Triple-Negative Breast Cancer

Activating immunogenic cell death (ICD) represents a promising therapeutic strategy for tumor immunotherapy. However, photodynamic therapy (PDT)-mediated ICD effect is severely limited due to the extremely short half-life and limited diffusion radius of reactive oxygen species (ROS), hindering effective endoplasmic reticulum (ER) stress induction. In addition, targeted therapy of triple-negative breast cancer (TNBC) remains hugely challenging due to the lack of expression of multiple receptors. Herein, we constructed a hierarchical targeting and controllable intelligent nanodelivery material Da-CD@CET@CQ based on poly-β-cyclodextrin with remarkable solubility and stability, loaded with a novel photosensitized ICD inducer, CET, and autophagy inhibitor chloroquine (CQ). Excitingly, Da-CD@CET@CQ NPs can accurately recognize TNBC tumor cells under the mediation of SRC protein. Moreover, CET could achieve observable enrichment in the ER and amplify the ICD effect by in situ ER PDT, which is further strengthened by the autophagy inhibition caused by CQ. All results show that Da-CD@CET@CQ NPs exhibited excellent targeting ability to tumor cells and ER and effectively enhanced synergistic immunotherapy of in situ ER PDT combined with autophagy inhibition, which significantly inhibited tumor growth and metastasis. Overall, our study provides a novel strategy and meaningful guideline for targeted-PDT-synergistic immunotherapy of TNBC.

Amplifying Ca2+ overload by engineered biomaterials for synergistic cancer therapy

Ca2+ overload is one of the most widely causes of inducing apoptosis, pyroptosis, immunogenic cell death, autophagy, paraptosis, necroptosis, and calcification of tumor cells, and has become the most valuable therapeutic strategy in the field of cancer treatment. Nevertheless, several challenges remain in translating Ca2+ overload-mediated therapeutic strategies into clinical applications, such as the precise control of Ca2+ dynamics, specificity of Ca2+ homeostasis dysregulation, as well as comprehensive mechanisms of Ca2+ regulation. Given this, we comprehensively reviewed the Ca2+-driven intracellular signaling pathways and the application of Ca2+-based biomaterials (such as CaCO3-, CaP-, CaO2-, CaSi-, CaF2-, and CaH2-) in mediating cancer diagnosis, treatment, and immunotherapy. Meanwhile, the latest researches on Ca2+ overload-mediated therapeutic strategies, as well as those combined with multiple-model therapies in mediating cancer immunotherapy are further highlighted. More importantly, the critical challenges and the future prospects of the Ca2+ overload-mediated therapeutic strategies are also discussed. By consolidating recent findings and identifying future research directions, this review aimed to advance the field of oncology therapy and contribute to the development of more effective and targeted treatment modalities.

Lysosomal damage due to cholesterol accumulation triggers immunogenic cell death

Cholesterol serves as a vital lipid that regulates numerous physiological processes. Nonetheless, its role in regulating cell death processes remains incompletely understood. In this study, we investigated the role of cholesterol trafficking in immunogenic cell death. Through cell-based drug screening, we identified two antidepressants, sertraline and indatraline, as potent inducers of the nuclear translocation of TFEB (transcription factor EB). Activation of TFEB was mediated through the autophagy-independent lipidation of MAP1LC3/LC3 (microtubule associated protein 1 light chain 3). Both compounds promoted cholesterol accumulation within lysosomes, resulting in lysosomal membrane permeabilization, disruption of autophagy and cell death that could be reversed by cholesterol depletion. Molecular docking analysis indicated that sertraline and indatraline have the potential to inhibit cholesterol binding to the lysosomal cholesterol transporters, NPC1 (NPC intracellular cholesterol transporter 1) and NPC2. This inhibitory effect might be further enhanced by the upregulation of NPC1 and NPC2 expression by TFEB. Both antidepressants also upregulated PLA2G15 (phospholipase A2 group XV), an enzyme that elevates lysosomal cholesterol. In cancer cells, sertraline and indatraline elicited immunogenic cell death, converting dying cells into prophylactic vaccines that were able to confer protection against tumor growth in mice. In a therapeutic setting, a single dose of each compound was sufficient to significantly reduce the outgrowth of established tumors in a T-cell-dependent manner. These results identify sertraline and indatraline as immunostimulatory agents for cancer treatment. More generally, this research shed light on novel therapeutic avenues harnessing lysosomal cholesterol transport to regulate immunogenic cell death.Abbreviation: ATG5: autophagy related 5; ATG13: autophagy related 13; DKO: double knockout; ICD: immunogenic cell death; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LAMP2: lysosomal associated membrane protein 2; LGALS3: galectin 3; LDL: low-density lipoprotein; LMP: lysosomal membrane permeabilization; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTX: mitoxantrone; NPC1: NPC intracellular cholesterol transporter 1; NPC2: NPC intracellular cholesterol transporter 2; TFE3: transcription factor E3; TFEB: transcription factor EB; ULK1: unc-51 like autophagy activating kinase 1.

Nanoassemblies loaded with low-dose paclitaxel can enhance the response of lung cancer immunotherapy by activating dendritic cells

Background

The immune tolerance of the tumor immune microenvironment (TIME) restricts the response to immune checkpoint inhibitors (ICIs). Targeted activation of dendritic cells (DCs) in the TIME seems to be a scheme for improving the therapeutic effect of ICIs treatment. The purpose of this study was to utilize nanotechnology to reprogram the immunosuppressive tumor immune microenvironment in situ, improving the response of ICIs to lung cancer.

Methods

In this study, a folic acid (FA)-modified nanoassembly (NA) loaded with low-dose paclitaxel (PTX) (FA-PTX NA), self-assembled by distearoylphosphatidylethanolamine-methoxy polyethylene glycol 2000-folic acid (DSPE-mPEG2000-FA) and PTX, was designed to reprogram the DC function of the TIME to sensitize cells to cancer immunotherapy. The characteristics of FA-PTX NAs were studied, and the cytotoxicity, cellular uptake, and DC stimulation of FA-PTX NAs were evaluated in vitro using a Lewis lung carcinoma (LLC) cell line and bone marrow-derived cells (BMDCs). Following this, the effect of the reprogrammed TIME and on the sensitization to immunotherapy in vivo were examined in a C57BL/6 mouse LLC subcutaneous xenograft model.

Results

The prepared FA-PTX NAs exhibited a slightly negative surface charge, appropriate size and shape, good drug release profiles, and high drug encapsulation efficiency and blood compatibility. The FA-PTX NAs were effectively uptaken by bone BMDCs, increasing the activation and expression of the costimulatory factor of BMDCs in vitro. In the LLC xenograft model treated with intravenous injection of FA-PTX NAs, the numbers of CD4+ and CD8+ T cells in the TIME increased significantly, the killing activity of tumor-specific cytotoxic T lymphocytes (CTLs) was significantly enhanced, and at the same time, the concentration of transforming growth factor β (TGF-β) decreased significantly. Furthermore, the infiltrated CD8+ T cells in TIME were mainly distributed in the tumor parenchyma. The combination of FA-PTX NAs and ICIs effectively inhibited the growth of LLC xenograft tumor, demonstrating a greater effect than that of ICIs alone. Moreover, it was found that apoptosis induction, increase in CD4+ and CD8+ T-cell infiltration, and improvement in the distribution of CD8+ T cells were involved in the anticancer mechanism of this combination treatment.

Conclusions

The NA loaded with low-dose PTX can reprogram the DC function in the TIME and exert a synergistic anticancer effect with ICIs in lung cancer treatment. Increased sensitization to ICI therapy as stimulated by PTX-enhanced NAs has potential applications in lung cancer immunotherapy.

Case report: Durable response of immuno-chemotherapy targeting a rare ROS1 fusion-positive extensive-stage SCLC patient after primary resistance to crizotinib

Background

Small cell lung cancer (SCLC) is characterized by an exceedingly low mutation rate in oncogenic driver alterations, and there are currently no articles or case reports documenting SCLC patients carrying ROS1 fusions. Tyrosine kinase inhibitors (TKIs) have demonstrated significant efficacy and safety in patients with ROS1 fusion-positive non-small cell lung cancer (NSCLC). However, effective treatment modalities for ROS1 fusion-positive SCLC patients remain poorly defined.

Materials and Methods

We report the first case of an extensive-stage SCLC (ES-SCLC) patient harboring ROS1 fusion, along with TP53, RB1, PTEN, and TERT mutations. The patient exhibited primary resistance to a 3-week course of crizotinib as first-line treatment. Following this, the patient was administered second-line therapy, including chemotherapy coupled with immune checkpoint inhibitor (ICI) and ICI maintenance treatment, resulting in a partial response (PR). Notably, the clinical response to second-line therapy persisted for over 19 months, surpassing the previously reported efficacy of immuno-chemotherapy in ES-SCLC cases (5.7 months) while maintaining a satisfactory quality of life.

Conclusion

We hypothesize that ROS1 fusion may not function as an oncogenic driver alteration in ES-SCLC. Immuno-chemotherapy, not ROS1-TKIs, might provide superior efficacy in ES-SCLC patients with ROS1 fusion.

Phagocytosis-Activating Nanocomplex Orchestrates Macrophage-Mediated Cancer Immunotherapy

The phagocytosis of macrophages to tumor cells represents an alluring strategy for cancer immunotherapy; however, its effectiveness is largely hindered by the detrimental upregulation of anti-phagocytic signals and insufficient expression of pro-phagocytic signals of tumor cells. Here, a pro-phagocytic polymer-based nanocomplex is designed to promote the macrophage engulfment of tumor cells through concurrent modulation of both the "eat me" and "don't eat me" signals. The nanocomplex MNCCD47i-CALRt is formed by complexing a synthetic PAMAM derivative (G4P-C7A) that is capable of intrinsically inducing the exposure of calreticulin (CALR, a crucial pro-phagocytic protein) and a small inference RNA that can inhibit the expression of CD47 (a primary anti-phagocytic protein). MNCCD47i-CALRt can significantly delay tumor growth and prolong the survival of tumor-bearing mice with negligible hematopoietic toxicity in multiple murine colorectal cancer models. Furthermore, the pro-phagocytic capacity of MNCCD47i-CALRt is validated in the patient-derived tumor organoid model. Collectively, the phagocytosis-promoting nanocomplex provides a simple and potent strategy for boosting macrophage-mediated cancer immunotherapy.

Emerging Role of the p53 Pathway in Modulating NK Cell-Mediated Immunity

The p53 pathway plays an important role in role in cancer immunity. Mutation or downregulation of the proteins in the p53 pathway are prevalent in many cancers, contributing to tumor progression and immune dysregulation. Recent findings suggest that the activity of p53 within tumor cells, immune cells, and the tumor microenvironment can play an important role in modulating NK cell-mediated immunity. Consequently, efforts to restore p53 pathway activity are being actively pursued to modulate this form of immunity. This review focuses on p53 activity regulating the infiltration and activation of NK cells in the tumor immune microenvironment. Furthermore, the impact of p53 and its regulation of NK cells on immunogenic cell death within solid tumors and the abscopal effect are reviewed. Finally, future avenues for therapeutically restoring p53 activity to improve NK cell-mediated antitumor immunity and optimize the effectiveness of cancer therapies are discussed.

Celastrol-loaded ginsenoside Rg3 liposomes enhance anti-programmed death ligand 1 immunotherapy by inducing immunogenic cell death in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC), characterized by high heterogeneity and invasiveness. Currently, inducing immunogenic cell death (ICD) of tumor cells through approaches such as radiotherapy and chemotherapy is an effective strategy to enhance the response to anti-programmed death-ligand 1 antibody (aPD-L1) therapy in TNBC. However, radiotherapy and chemotherapy treatments often upregulate PD-L1 expression in tumor cells, thereby weakening the tumor cells' response to aPD-L1. Celastrol exhibits broad-spectrum and potent anti-tumor activity, efficiently inducing ICD without increasing PD-L1 levels in tumor cells.

PURPOSE

This study aims to elucidate the tumor-targeting effects of celastrol-loaded liposomes and its synergistic efficacy and mechanism of action in combination with aPD-L1 against TNBC.

METHODS

The Rg3 liposomes loaded with celastrol (Cel-Rg3-Lp) were prepared using the thin-film hydration method. BALB/c mice were utilized to establish an in situ breast cancer model. Mice were intravenously injected with Cel-Rg3-Lp at a dosage of celastrol 1 mg/kg once every two days for a total of 7 injections. Flow cytometry, western blot, and immunofluorescence techniques were employed to investigate the synergistic effects and mechanisms of Cel-Rg3-Lp combined with aPD-L1 in the treatment of TNBC.

RESULTS

The findings of this study demonstrate that after 7 administrations of Cel-Rg3-Lp (1 mg/kg celastrol, intravenously), significant anti-tumor effects are observed, including the recruitment of CD8+T cells and dendritic cells (DCs), while reducing the infiltration of immunosuppressive cells. The therapeutic efficacy was further enhanced when combined with aPD-L1. Additionally, Cel-Rg3-Lp markedly downregulated glucose-regulated protein 78 (GRP78) expression, thereby inducing ICD in tumor cells.

CONCLUSION

This study successfully constructed a multifunctional liposome and proposed a mechanism for inducing ICD through the GRP78-endoplasmic reticulum stress pathway. The liposome downregulates GRP78, triggering endoplasmic reticulum stress in tumor cells, inducing ICD, activating DCs, and enhancing antigen presentation to T cells. This improves the tumor immune microenvironment and provides a theoretical foundation for combining Cel-Rg3-Lp with aPD-L1 in the treatment of TNBC. This mechanism opens unique prospects for using celastrol in TNBC therapy and enhancing the effectiveness of immunotherapy.

Immunomodulation on tumor immune microenvironment in acquired targeted therapy resistance and implication for immunotherapy resistance

The emergence of molecularly targeted therapies and immunotherapies has revolutionized cancer treatment, yet the optimal sequencing of these modalities remains debated. While targeted therapies often induce initial immunostimulatory effects, the development of resistance is accompanied by dynamic alterations in the tumor-immune microenvironment. These changes can promote tumor growth, hinder immune surveillance, and contribute to subsequent immunotherapy resistance. This review focuses on solid tumors and summarizes the immunomodulatory effects arising in the context of targeted therapy resistance, highlighting the challenges they pose for the subsequent immunotherapy efficacy.

Mitochondria-targeted photothermal-chemodynamic therapy enhances checkpoint blockade immunotherapy on colon cancer

Immunotherapy has emerged as a hotspot for cancer treatment. However, the response rate of monotherapy remains relatively low in clinical settings. Photothermal therapy (PTT), which employs light energy to ablate tumors, can also activate tumor-specific immune responses. This effect has been attributed in several studies to the release of damage-associated molecular patterns (DAMPs) triggered by mitochondrial injury. We propose that mitochondria-targeted PTT may better synergize with immunotherapy. Herein, we constructed a multifunctional nanoplatform that enables mitochondria-targeted photothermal-chemodynamic combination therapy by conjugating indocyanine green-thiol (ICG-SH) and mercaptoethyl-triphenylphosphonium (TPP-SH) onto polyvinyl pyrrolidone (PVP)-coated gold-copper nanoparticles (AIT). Upon near-infrared light (NIR) irradiation, AIT ablates cancer cells and amplifies the effect of chemodynamic therapy (CDT), thereby inducing apoptosis in the tumor. The combination of CDT and PTT promotes immunogenic cell death, which could synergize with checkpoint blockade immunotherapy. In a bilateral mouse colon cancer model, we observed complete eradication of light-irradiated primary tumors and significant inhibition of distant untreated tumors in the group treated with AIT plus anti-PD-1 (αPD-1). We found a significant increase in serum levels of pro-inflammatory factors, including interleukin-6 (IL-6), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α), following PTT/CDT/immunotherapy treatment, suggesting effective activation of the immune response. The enhanced immunogenicity caused by AIT with αPD-1 treatment resulted in efficient antigen presentation, as indicated by the increased infiltration of dendritic cells (DCs) into the tumor-draining lymph nodes (LNs). We also observed enhanced infiltration of CD8+ T cells in distant tumors in the AIT with αPD-1 group compared to αPD-1 alone. Hence, mitochondria-targeting represents an effective strategy to potentiate the combination of photothermal, chemodynamic, and immune checkpoint blockade therapies for the treatment of metastatic cancer.

Adoptive immune cell therapy for colorectal cancer

Colorectal cancer (CRC) is a major cause of cancer-related morbidity and mortality worldwide, with limited options for patients at advanced stages. Immunotherapy, particularly immune cell-based therapies, has gained significant attention as an innovative approach for targeting CRC. This review summarizes the progress in various immune cell therapies, including DC vaccine, CAR/TCR-T cells, CAR-NK cells et al, each engineered to recognize and attack cancer cells expressing specific antigens. CAR-T cell therapy, which has been successful in hematologic cancers, faces challenges in CRC due to the solid tumor microenvironment, which limits cell infiltration and persistence. CAR-NK cells, CAR-M and CAR-γδ T cells, however, offer alternative strategies due to their unique properties, such as the ability to target tumor cells without prior sensitization and a lower risk of inducing severe cytokine release syndrome. Recent advances in lentiviral transduction have enabled effective expression of CARs on NK and γδ T cells, providing promising preclinical results in CRC models. This review explores the mechanisms, tumor targets, preclinical studies, and early-phase clinical trials of these therapies, addressing key challenges such as enhancing specificity to tumor antigens and overcoming the immunosuppressive tumor microenvironment. The potential of combination therapies, including immune checkpoint inhibitors and cytokine therapy, is also discussed some as a means to improve the effectiveness of immune cell-based treatments for CRC. Continued research is essential to translate these promising approaches into clinical settings, offering new hope for CRC patients.

Taurine and proline promote lung tumour growth by co-regulating Azgp1/mTOR signalling pathway

Accurate metabolic biomarkers for lung cancer prognosis remain scarce but crucial. Taurine and proline, two metabolites, are consistently elevated across various cancer stages in previous studies, hinting at their potential role in disease progression. This study is the first to reveal how these metabolites contribute to poor prognosis. Transcriptomic analysis uncovered that taurine and proline downregulated Zinc-α2-glycoprotein (Azgp1), a gene linked to key metabolic pathways. Additionally, Azgp1 could also significantly affect downstream lipid metabolic pathways in lung cancer. Both taurine and proline influenced lipid metabolism via mammalian target of rapamycin (mTOR). When Azgp1 was overexpressed, lung cancer progression slowed significantly, alongside reduced mTOR activity. These findings underscore the pro-cancer role of taurine and proline, highlighting the Azgp1/mTOR axis as a vital, yet overlooked, pathway in lung cancer. This study not only advances our understanding but also identifies new therapeutic avenues.

Regulation of immunogenic cell death and potential applications in cancer therapy

Immunogenic cell death (ICD), a type of regulatory cell death, plays an important role in activating the adaptive immune response. Activation of the tumor-specific immune response is accompanied by the cell surface exposure of calreticulin and heat-shock proteins, the secretion of adenosine triphosphate, and the release of high mobility group box-1. In this review, we summarize and classify the latest types of ICD inducers and their molecular mechanisms, and discuss the effects and potential applications of inducing ICD by chemotherapy drugs, targeted drugs, and oncolytic viruses in clinical research. We also explore the potential role of epigenetic modifiers in the induction of ICD, and clarify the synergistic anti-tumor effects of nano-pulse stimulation, radiosensitizers for radiotherapy, photosensitizers for photodynamic therapy, photothermal therapy, and other physical stimulation, combined with radiotherapy and chemotherapy induced-ICD, in multimodal immunotherapy. In addition, we elucidate the molecular mechanism of ICD in detail, including the calcium imbalance, mitochondrial stress, and the interactions in the tumor microenvironment. Ultimately, this review aims to offer deeper insight into the factors and mechanisms of ICD induction and provide a theoretical basis for the future development of ICD-based immunotherapy.

Injectable celastrol-loading emulsion hydrogel for immunotherapy of low-immunogenic cancer

Immunotherapy, exemplified by immune checkpoint blockade (ICB), has been extensively employed in antitumor treatments. Nevertheless, its efficacy in addressing low-immunogenic tumors has not yielded satisfactory results, primarily due to the depletion and inadequate infiltration of effector T cells within the tumor microenvironment (TME). Here, we construct an injectable water-in-oil emulsion hydrogel to load clinically used Celastrol (Gel@Cel), which addresses the limitations of Cel's hydrophobicity. Cel can both inhibit tumor cell proliferation and promote tumor cell apoptosis, while simultaneously inducing immunogenic cell death, through activation of the AKT and MAPK pathways. In a model of clinically refractory hepatocellular carcinoma with malignant ascites, intraperitoneal administration of Gel@Cel significantly inhibits tumor progression and activates antitumor immune effects through lipase-controlled release of Cel, as compared to free Cel. Intriguingly, the Gel@Cel induces the activation of dendritic cells, resulting in the infiltration of cytotoxic T cells in the TME of ascites. Furthermore, the administration of Cel increases the expression of programmed cell death protein ligand-1 (PD-L1) in tumor cells. Moreover, combining the PD-1 antibody (αPD-1) with Gel@Cel further enhances the antitumor effect and amplifies the immune activation. In conclusion, Gel@Cel exhibits promising therapeutic potential in the treatment of low-immunogenic tumors, especially when combined with ICB therapy.

Immunogenic Cell Death Inducers in Cancer Immunotherapy to Turn Cold Tumors into Hot Tumors

The combination of chemotherapeutic agents with immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment. However, its success is often limited by insufficient immune priming in certain tumors, including pediatric malignancies. In this report, we explore clinical trials currently investigating the use of immunogenic cell death (ICD)-inducing chemotherapies in combination with ICIs for both adult and pediatric cancers. Given the limited clinical data available for pediatric tumors, we focused on recent preclinical studies evaluating the efficacy of these combinations in neuroblastoma (NB). Finally, to address this gap, we propose an innovative strategy to assess the impact of ICD-inducing chemotherapies on antitumor immune responses in NB. Using tumor spheroids derived from a transgenic NB mouse model, we validated our previous in vivo findings concerning how anthracyclines, specifically mitoxantrone and doxorubicin, significantly enhance MHC class I surface expression, stimulate IFNγ and granzyme B production by CD8+ T cells and NK cells, and promote immune cell recruitment. Importantly, these anthracyclines also upregulated PD-L1 expression on NB spheroids. This screening platform yielded results similar to in vivo findings, demonstrating that mitoxantrone and doxorubicin are the most potent immunomodulatory agents for NB. These data suggest that the creation of libraries of ICD inducers to be tested on tumor spheroids could reduce the number of combinations to be tested in vivo, in line with the principles of the 3Rs. Furthermore, these results highlight the potential of chemo-immunotherapy regimens to counteract the immunosuppressive tumor microenvironment in NB, paving the way for improved therapeutic strategies in pediatric cancers. They provide compelling evidence to support further clinical investigations of these combinations to enhance outcomes for children with malignancies.

Phaseolus acutifolius Recombinant Lectin Exerts Differential Proapoptotic Activity on EGFR+ and EGFR- Colon Cancer Cells and Provokes T Cell-Assisted Antitumor Responses in Mice

Background:rTBL-1, a recombinant lectin from Phaseolus acutifolius, exhibit proapoptotic activity on colon cancer cells and inhibitory properties on colon tumorigenesis in vivo. Apoptosis has been associated with a phospho-EGFR/phospho-p38/phospho-p53 mechanistic axis. Immunogenicity data have been observed in treated animals, but its possible involvement in the antitumor response remained unexplored. Objective: We investigated whether the cytotoxic activity of rTBL-1 depends on EGFR and its capacity to produce antitumor responses on syngeneic colon cancer in mice, with and without T cells, in order to explore its possible involvement in the process. Results:rTBL-1 exhibited cytotoxic effects in a concentration-dependent manner in both EGFR+ (MC-38) and EGFR- (CT-26) colon cancer cells with LC50 values of 23.50 and 30.01 µg/mL, respectively (p = 0.063). Apoptotic effects were slower and longer-lasting in MC-38 than in CT-26 cells. Significant increases in caspase-3 proteolytic activation and PARP1 cleavage were detected in both cell types, despite PARP1 rheostasis in CT-26 cells. Intralesional treatment with rTBL-1 inhibited the growth of established tumors in immunocompetent BALB/c mice in 27.81% (p = 0.0008) with a benefit in survival (p = 0.022), but not in immunodeficient BALB/c nude mice. Conclusions:rTBL-1 induces apoptosis in colon cancer cells by EGFR independent mechanisms, although its presence could be related to deeper responses. Unresponsiveness in nude mice indicated that rTBL-1 antitumor effect is the synergistic result of apoptosis induction and T cell-mediated cytotoxicity in the tumor. Future studies will focus on the immunogenic effects triggered by the antitumor activity of rTBL-1 in colon cancer.

The circRNA cEMSY Induces Immunogenic Cell Death and Boosts Immunotherapy Efficacy in Lung Adenocarcinoma

Immunogenic cell death (ICD) induces an active immune response. Activating ICD represents a potential approach to boost the antitumor activity of immunotherapy, highlighting the need to identify effective and safe ICD inducers. In this study, we identified a conserved, ICD-related circular RNA cEMSY by systematically screening ICD models induced by multiple cell stressors in lung adenocarcinoma. cEMSY triggered ICD in lung adenocarcinoma cells both in vitro and in vivo, leading to the release of damage-associated molecular patterns and promoting T-cell cross-priming by dendritic cells. Notably, the intratumoral delivery of lipid nanoparticle-encapsulated cEMSY induced a potent antitumor immune response in an immunosuppressed tumor model, which synergized with PD-1 blockade to facilitate long-term antitumor immunity with no apparent toxicities. Mechanistically, cEMSY mediated mitochondrial aggregation of the RNA-binding protein TDP-43 that enabled leakage of mitochondrial DNA to stimulate the cGAS-STING pathway, activating the antiviral immune response. Clinically, elevated expression of cEMSY correlated with enhanced infiltration of dendritic cells and CD8+ T cells and favorable immunotherapy response in lung adenocarcinoma. Together, these findings support the dual potential of cEMSY as a target and biomarker for improving immune checkpoint inhibitor responses in lung adenocarcinoma. Significance: cEMSY is a safe and effective immunogenic cell death inducer that synergizes with PD-1 blockade in lung adenocarcinoma, providing a potential strategy to enhance the efficacy of tumor immunotherapy.

Dramatic response to crizotinib through MET phosphorylation inhibition in rare TFG-MET fusion advanced squamous cell lung cancer

With the widespread use of next-generation sequencing (NGS) for solid tumors, mesenchymal-to-epithelial transition factor (MET) rearrangement/fusion has been confirmed in multiple cancer types. MET amplification and MET exon 14 skipping mutations induce protein autophosphorylation; however, the pathogenic mechanism and drug sensitivity of MET fusion remain unclear. The following report describes the clinical case of a patient diagnosed with squamous lung cancer bearing a TFG-MET gene fusion. In vitro assays demonstrated MET phosphorylation and oncogenic capacity due to the TFG-MET rearrangement, both of which were inhibited by crizotinib treatment. The patient was treated with crizotinib, which resulted in sustained partial remission for more than 17 months. Collectively, cellular analyses and our case report emphasize the potential of MET fusion as a predictive biomarker for personalized target therapy for solid tumors.

Injecting hope: the potential of intratumoral immunotherapy for locally advanced and metastatic cancer

Despite enormous progress, advanced cancers are still one of the most serious medical problems in current society. Although various agents and therapeutic strategies with anticancer activity are known and used, they often fail to achieve satisfactory long-term patient outcomes and survival. Recently, immunotherapy has shown success in patients by harnessing important interactions between the immune system and cancer. However, many of these therapies lead to frequent side effects when administered systemically, prompting treatment modifications or discontinuation or, in severe cases, fatalities. New therapeutic approaches like intratumoral immunotherapy, characterized by reduced side effects, cost, and systemic toxicity, offer promising prospects for future applications in clinical oncology. In the context of locally advanced or metastatic cancer, combining diverse immunotherapeutic and other treatment strategies targeting multiple cancer hallmarks appears crucial. Such combination therapies hold promise for improving patient outcomes and survival and for promoting a sustained systemic response. This review aims to provide a current overview of immunotherapeutic approaches, specifically focusing on the intratumoral administration of drugs in patients with locally advanced and metastatic cancers. It also explores the integration of intratumoral administration with other modalities to maximize therapeutic response. Additionally, the review summarizes recent advances in intratumoral immunotherapy and discusses novel therapeutic approaches, outlining future directions in the field.

Kinetic Assessment of HMGB1 Exodus by Automated Live Cell Imaging

The successful implementation of immune checkpoint inhibitors (ICIs) immunotherapy into clinical routine has underlined the importance of immunotherapy for the treatment of cancer. Nevertheless, benefits from ICI monotherapy remain limited to a subset of patients. The induction of immunogenic cell death (ICD) can prime tumors for subsequent ICI via the onset of adaptive immune responses leading to an infiltration of cytotoxic T lymphocytes. The nuclear and cellular nuclear release of high mobility group box 1 (HMGB1) is one of the hallmarks of ICD. Binding of HMGB1 to Toll-like receptor 4 (TLR4) expressed on dendritic cells plays a pivotal role in stimulating their maturation and antigen presentation, facilitating the onset of adaptive immunity. Here we describe microscopic assessments of HMGB1 release that can be applied to the screening of chemical compound libraries for novel ICD inducing agents. Thus, quantitative measurement of HMGB1 release kinetics can be useful for the discovery of new immuno-oncology drugs.

Immunogenic cell death-related cancer-associated fibroblast clusters and prognostic risk model in cervical cancer

Cervical cancer (CC) remains a leading cause of female cancer mortality globally. Immunogenic cell death (ICD) influences the tumor microenvironment (TME) and adaptive immune responses. Cancer-associated fibroblasts (CAFs) within the TME suppress anti-tumor immunity and contribute to CC progression. This study identified three ICD-related CAF clusters linked to patient survival, including IL6+CAF and ILR1+CAF, which were associated with clinical outcomes. Using a nine-gene risk model, patients were stratified into risk groups, with high-risk individuals showing worse survival and correlations with pathways such as hypoxia and TGFβ. The model also predicted immunotherapy responses, highlighting immune infiltration differences across risk groups. These findings provide insights into the role of CAF clusters in CC and present a risk model that supports prognosis prediction and personalized therapy.

Overcoming tyrosine kinase inhibitor resistance in lung cancer brain metastasis with CTLA4 blockade

Lung cancer brain metastasis (LCBM) poses a significant clinical challenge due to acquired resistance to tyrosine kinase inhibitor (TKI) treatment. To elucidate its underlying mechanisms, we employed single-cell RNA sequencing analysis on surgically obtained LCBM samples with diverse genetic backgrounds and TKI treatment histories. Our study uncovers that TKI treatment elevates the immune checkpoint CTLA4 expression in T cells, promoting an immune-suppressive microenvironment. This immunomodulation is initiated by tumor-derived HMGB1 in response to TKIs. In LCBM syngeneic murine models with TKI-sensitive or TKI-resistant EGFR mutations, combining CTLA4 blockade with TKIs demonstrates enhanced efficacy over TKI monotherapy or TKIs with PD1 blockade. These findings provide insights into the TKI resistance mechanisms and highlight the potential of CTLA4 blockade in effectively overcoming TKI resistance in LCBM.

Regulation of NRF2 by Phosphoinositides and Small Heat Shock Proteins

Reactive oxygen species (ROS) are generated by aerobic metabolism, and their deleterious effects are buffered by the cellular antioxidant response, which prevents oxidative stress. The nuclear factor erythroid 2-related factor 2 (NRF2) is a master transcriptional regulator of the antioxidant response. Basal levels of NRF2 are kept low by ubiquitin-dependent degradation of NRF2 by E3 ligases, including the Kelch-like ECH-associated protein 1 (KEAP1). Here, we show that the stability and function of NRF2 is regulated by the type I phosphatidylinositol phosphate kinase γ (PIPKIγ), which binds NRF2 and transfers its product phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2 ) to NRF2. PtdIns(4,5)P 2 binding recruits the small heat shock protein HSP27 to the complex. Silencing PIPKIγ or HSP27 destabilizes NRF2, reduces expression of its target gene HO-1, and sensitizes cells to oxidative stress. These data demonstrate an unexpected role of phosphoinositides and HSP27 in regulating NRF2 and point to PIPKIγ and HSP27 as drug targets to destabilize NRF2 in cancer.

In brief

Phosphoinositides are coupled to NRF2 by PIPKIγ, and HSP27 is recruited and stabilizes NRF2, promoting stress-resistance.

The enhancement of immunoactivity induced by immunogenic cell death through serine/threonine kinase 10 inhibition: a potential therapeutic strategy

Introduction

Immunogenic cell death (ICD) is capable of activating the anti-tumor immune response of the organism; however, it is concurrently a complex process involving multiple factors. The specific factors that impact the occurrence of ICD remain undefined.

Methods

Through cluster analysis, patient specimens retrieved from the TARGET, TCGA, and GEO AML databases were categorized into two subtypes based on the expression levels of ICD-related genes: ICD-high and ICD-low. We compared the prognostic survival outcomes, pathway enrichment analysis, and immune cell infiltration between these two subtypes. Additionally, we identified factors related to AML development from multiple databases and verified the role of these factors both in vivo and in vitro in activating the immune response during the occurrence of ICD.

Results and discussion

In the ICD-high subtype, there was a notable increase in the abundance of immune cell populations, along with the enrichment of pathways pertinent to the activation of various immune cells. Despite these immunological enhancements, this subgroup demonstrated a poorer prognosis. This phenomenon was consistently observed across various additional AML datasets, leading us to hypothesize that elevated expression of ICD genes does not invariably correlate with a favorable prognosis. Notably, STK10 exhibited elevated expression in AML, was associated with a poor prognosis, and showed synchronous expression patterns with ICD genes. Inhibition of STK10 led to the activation of ICD and the induction of an antitumor response. Moreover, when combined with other ICD inducers, it produced a synergistic anti-tumor effect. Our results reveal the impact of STK10 on ICD and underscore its key role in initiating ICD.

Iron Boosts Antitumor Type 1 T-cell Responses and Anti-PD1 Immunotherapy

Cancers only develop if they escape immunosurveillance, and the success of cancer immunotherapies relies in most cases on their ability to restore effector T-cell functions, particularly IFNγ production. Revolutionizing the treatment of many cancers, immunotherapies targeting immune checkpoints such as PD1 can increase survival and cure patients. Unfortunately, although immunotherapy has greatly improved the prognosis of patients, not all respond to anti-PD1 immunotherapy, making it crucial to identify alternative treatments that could be combined with current immunotherapies to improve their effectiveness. Here, we show that iron supplementation significantly boosts T-cell responses in vivo and in vitro. The boost was associated with a metabolic reprogramming of T cells in favor of lipid oxidation. We also found that the "adjuvant" effect of iron led to a marked slowdown of tumor cell growth after tumor cell line transplantation in mice. Specifically, our results suggest that iron supplementation promotes antitumor responses by increasing IFNγ production by T cells. In addition, iron supplementation improved the efficacy of anti-PD1 cancer immunotherapy in mice. Finally, our study suggests that, in patients with cancer, the quality and efficacy of the antitumor response following anti-PD1 immunotherapy may be modulated by plasma ferritin levels. In summary, our results suggest the benefits of iron supplementation on the reactivation of antitumor responses and support the relevance of a fruitful association between immunotherapy and iron supplementation.

Mechanisms of resistance to tyrosine kinase inhibitor-targeted therapy and overcoming strategies

Tyrosine kinase inhibitor (TKI)-targeted therapy has revolutionized cancer treatment by selectively blocking specific signaling pathways crucial for tumor growth, offering improved outcomes with fewer side effects compared with conventional chemotherapy. However, despite their initial effectiveness, resistance to TKIs remains a significant challenge in clinical practice. Understanding the mechanisms underlying TKI resistance is paramount for improving patient outcomes and developing more effective treatment strategies. In this review, we explored various mechanisms contributing to TKI resistance, including on-target mechanisms and off-target mechanisms, as well as changes in the tumor histology and tumor microenvironment (intrinsic mechanisms). Additionally, we summarized current therapeutic approaches aiming at circumventing TKI resistance, including the development of next-generation TKIs and combination therapies. We also discussed emerging strategies such as the use of dual-targeted antibodies and PROteolysis Targeting Chimeras. Furthermore, we explored future directions in TKI-targeted therapy, including the methods for detecting and monitoring drug resistance during treatment, identification of novel targets, exploration of dual-acting kinase inhibitors, application of nanotechnologies in targeted therapy, and so on. Overall, this review provides a comprehensive overview of the challenges and opportunities in TKI-targeted therapy, aiming to advance our understanding of resistance mechanisms and guide the development of more effective therapeutic approaches in cancer treatment.

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.

Dihydroartemisinin restores the immunogenicity and enhances the anticancer immunosurveillance of cisplatin by activating the PERK/eIF2α pathway

BACKGROUND

Immunosurveillance is pivotal in the effectiveness of anticancer therapies and tumor control. The ineffectiveness of cisplatin in activating the immunosurveillance is attributed to its lack of adjuvanticity resulting from its inability to stimulate endoplasmic reticulum stress. Dihydroartemisinin demonstrates the anti-tumor effects through various mechanisms, including the activation of the endoplasmic reticulum stress. This study aimed to develop a novel strategy to enhance the immunogenicity of dying tumor cells by combining cisplatin with dihydroartemisinin, thereby triggering effective anti-tumor immunosurveillance and improving the efficacy of cisplatin in clinical practice.

METHODS

Lewis lung carcinoma (LLC) and CT26 colon cancer cell lines and subcutaneous tumor models were used in this study. The importance of immunosurveillance was validated in both immunocompetent and immunodeficient mouse models. The ability of dihydroartemisinin and cisplatin therapy to induce immunogenic cell death and tumor growth control in vivo was validated by prophylactic tumor vaccination and therapeutic tumor models. The underlying mechanism was elucidated through the pharmaceutical or genetic intervention of the PERK/eIF2α pathway in vitro and in vivo.

RESULTS

Dihydroartemisinin enhanced the generation of reactive oxygen species in cisplatin-treated LLC and CT26 cancer cells. The combination treatment of dihydroartemisinin with cisplatin promoted cell death and ensured an optimal release of damage-associated molecular patterns from dying cancer cells, promoting the phagocytosis of dendritic cells. In the tumor vaccination model, we confirmed that dihydroartemisinin plus cisplatin treatment induced immunogenic cell death. Utilizing immunocompetent and immunodeficient mouse models, we further demonstrated that the combination treatment suppressed the tumor growth of CT26 colon cancer and LLC lung cancer, leading to an improved prognosis through the restoration of cytotoxic T lymphocyte responses and reinstatement of anti-cancer immunosurveillance in vivo. Mechanistically, dihydroartemisinin restored the immunogenicity of cisplatin by activating the adjuvanticity of damage-associated molecular patterns, such as calreticulin exposure, through the PERK/eIF2α pathway. Additionally, the inhibition of eIF2α phosphorylation attenuated the anti-tumor efficiency of C + D in vivo.

CONCLUSIONS

We highlighted that dihydroartemisinin acts as an immunogenic cell death rescuer for cisplatin, activating anticancer immunosurveillance in a PERK/eIF2α-dependent manner and offering a strategy to enhance the anti-tumor efficacy of cisplatin in clinical practice.

Characterizing the immune tumor microenvironment in ALK fusion-positive lung cancer: state-of-the-art and therapeutical implications

INTRODUCTION

Approximately 5% of non-small cell lung cancer (NSCLC), exhibits anaplastic lymphoma kinase (ALK) rearrangements. EML4-ALK fusions account for over 90% of ALK rearrangements in NSCLC. The advent of treatment targeting ALK has significantly improved survival rates in patients with advanced ALK-positive NSCLC. However, the emergence of resistance mechanisms and the subsequent progression disease inevitably occurs. The tumor immune microenvironment (TIME) plays a pivotal role in lung cancer, influencing disease development, patient's outcomes, and response to treatments.

AREAS COVERED

The aim of this review is to provide a comprehensive characterization of the TIME in ALK rearranged NSCLC and its intrinsic plasticity under treatment pressure.

EXPERT OPINION

Recognizing the fundamental role of the TIME in cancer progression has shifted the paradigm from a tumor cell-centric perspective to the understanding of a complex tumor ecosystem. Understanding the intricate dynamics of the TIME, its influence on treatment response, and the potential of immunotherapy in patients with ALK-positive NSCLC are currently among the primary research objectives in this patient population.

Therapeutic strategies of targeting non-apoptotic regulated cell death (RCD) with small-molecule compounds in cancer

Regulated cell death (RCD) is a controlled form of cell death orchestrated by one or more cascading signaling pathways, making it amenable to pharmacological intervention. RCD subroutines can be categorized as apoptotic or non-apoptotic and play essential roles in maintaining homeostasis, facilitating development, and modulating immunity. Accumulating evidence has recently revealed that RCD evasion is frequently the primary cause of tumor survival. Several non-apoptotic RCD subroutines have garnered attention as promising cancer therapies due to their ability to induce tumor regression and prevent relapse, comparable to apoptosis. Moreover, they offer potential solutions for overcoming the acquired resistance of tumors toward apoptotic drugs. With an increasing understanding of the underlying mechanisms governing these non-apoptotic RCD subroutines, a growing number of small-molecule compounds targeting single or multiple pathways have been discovered, providing novel strategies for current cancer therapy. In this review, we comprehensively summarized the current regulatory mechanisms of the emerging non-apoptotic RCD subroutines, mainly including autophagy-dependent cell death, ferroptosis, cuproptosis, disulfidptosis, necroptosis, pyroptosis, alkaliptosis, oxeiptosis, parthanatos, mitochondrial permeability transition (MPT)-driven necrosis, entotic cell death, NETotic cell death, lysosome-dependent cell death, and immunogenic cell death (ICD). Furthermore, we focused on discussing the pharmacological regulatory mechanisms of related small-molecule compounds. In brief, these insightful findings may provide valuable guidance for investigating individual or collaborative targeting approaches towards different RCD subroutines, ultimately driving the discovery of novel small-molecule compounds that target RCD and significantly enhance future cancer therapeutics.

Loss of GABARAP mediates resistance to immunogenic chemotherapy in multiple myeloma

ABSTRACT

Immunogenic cell death (ICD) is a form of cell death by which cancer treatments can induce a clinically relevant antitumor immune response in a broad range of cancers. In multiple myeloma (MM), the proteasome inhibitor bortezomib is an ICD inducer and creates durable therapeutic responses in patients. However, eventual relapse and resistance to bortezomib appear inevitable. Here, by integrating patient transcriptomic data with an analysis of calreticulin (CRT) protein interactors, we found that GABA type A receptor-associated protein (GABARAP) is a key player whose loss prevented tumor cell death from being perceived as immunogenic after bortezomib treatment. GABARAP is located on chromosome 17p, which is commonly deleted in patients with high risk MM. GABARAP deletion impaired the exposure of the eat-me signal CRT on the surface of dying MM cells in vitro and in vivo, thus reducing tumor cell phagocytosis by dendritic cells and the subsequent antitumor T-cell response. Low GABARAP was independently associated with shorter survival in patients with MM and reduced tumor immune infiltration. Mechanistically, we found that GABARAP deletion blocked ICD signaling by decreasing autophagy and altering Golgi apparatus morphology, with consequent defects in the downstream vesicular transport of CRT. Conversely, upregulating autophagy using rapamycin restored Golgi morphology, CRT exposure, and ICD signaling in GABARAPKO cells undergoing bortezomib treatment. Therefore, coupling an ICD inducer, such as bortezomib, with an autophagy inducer, such as rapamycin, may improve patient outcomes in MM, in which low GABARAP in the form of del(17p) is common and leads to worse outcomes.

Chemical conjugation mitigates immunotoxicity of chemotherapy via reducing receptor-mediated drug leakage from lipid nanoparticles

Immunotoxicity remains a major hindrance to chemotherapy in cancer therapy. Nanocarriers may alleviate the immunotoxicity, but the optimal design remains unclear. Here, we created two variants of maytansine (DM1)-loaded synthetic high-density lipoproteins (D-sHDL) with either physically entrapped (ED-sHDL) or chemically conjugated (CD-sHDL) DM1. We found that CD-sHDL showed less accumulation in the tumor draining lymph nodes (DLNs) and femur, resulting in a lower toxicity against myeloid cells than ED-sHDL via avoiding scavenger receptor class B type 1 (SR-B1)-mediated DM1 transportation into the granulocyte-monocyte progenitors and dendritic cells. Therefore, higher densities of lymphocytes in the tumors, DLNs, and blood were recorded in mice receiving CD-sHDL, leading to a better efficacy and immune memory of CD-sHDL against colon cancer. Furthermore, liposomes with conjugated DM1 (CD-Lipo) showed lower immunotoxicity than those with entrapped drug (ED-Lipo) through the same mechanism after apolipoprotein opsonization. Our findings highlight the critical role of drug loading patterns in dictating the biological fate and activity of nanomedicine.

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.

Engineering nanomedicines for immunogenic eradication of cancer cells: Recent trends and synergistic approaches

Resistance to cancer immunotherapy is mainly attributed to poor tumor immunogenicity as well as the immunosuppressive tumor microenvironment (TME) leading to failure of immune response. Numerous therapeutic strategies including chemotherapy, radiotherapy, photodynamic, photothermal, magnetic, chemodynamic, sonodynamic and oncolytic therapy, have been developed to induce immunogenic cell death (ICD) of cancer cells and thereby elicit immunogenicity and boost the antitumor immune response. However, many challenges hamper the clinical application of ICD inducers resulting in modest immunogenic response. Here, we outline the current state of using nanomedicines for boosting ICD of cancer cells. Moreover, synergistic approaches used in combination with ICD inducing nanomedicines for remodeling the TME via targeting immune checkpoints, phagocytosis, macrophage polarization, tumor hypoxia, autophagy and stromal modulation to enhance immunogenicity of dying cancer cells were analyzed. We further highlight the emerging trends of using nanomaterials for triggering amplified ICD-mediated antitumor immune responses. Endoplasmic reticulum localized ICD, focused ultrasound hyperthermia, cell membrane camouflaged nanomedicines, amplified reactive oxygen species (ROS) generation, metallo-immunotherapy, ion modulators and engineered bacteria are among the most innovative approaches. Various challenges, merits and demerits of ICD inducer nanomedicines were also discussed with shedding light on the future role of this technology in improving the outcomes of cancer immunotherapy.

Identification of immunogenic cell death-related damage-related molecular patterns (DAMPs) to predict outcomes in patients with head and neck squamous cell carcinoma

PURPOSE

Head and neck cancer is the sixth most common type of cancer worldwide, wherein the immune responses are closely associated with disease occurrence, development, and prognosis. Investigation of the role of immunogenic cell death-related genes (ICDGs) in adaptive immune response activation may provide cues into the mechanism underlying the outcome of HNSCC immunotherapy.

METHODS

ICDGs expression patterns in HNSCC were analyzed, after which consensus clustering in HNSCC cohort conducted. A 4-gene prognostic model was constructed through LASSO and Cox regression analyses to analyze the prognostic index using the TCGA dataset, followed by validation with two GEO datasets. The distribution of immune cells and the response to immunotherapy were compared between different risk subtypes through multiple algorithms. Moreover, immunohistochemical (IHC) analyses were conducted to validate the prognostic value of HSP90AA1 as a predictor of HNSCC patient prognosis. In vitro assays were performed to further detect the effect of HSP90AA1 in the development of HNSCC.

RESULTS

A novel prognostic index based on four ICDGs was constructed and proved to be useful as an independent factor of HNSCC prognosis. The risk score derived from this model grouped patients into high- and low-risk subtypes, wherein the high-risk subtype had worse survival outcomes and poorer immunotherapy response. IHC analysis validated the applicability of HSP90AA1 as a predictor of prognosis of HNSCC patients. HSP90AA1 expression in tumor cells promotes the progression of HNSCC.

CONCLUSIONS

Together, these results highlight a novel four-gene prognostic signature as a valuable tool to assess survival status and prognosis of HNSCC patients.

Targeting TACC3 Induces Immunogenic Cell Death and Enhances T-DM1 Response in HER2-Positive Breast Cancer

Trastuzumab emtansine (T-DM1) was the first and one of the most successful antibody-drug conjugates (ADC) approved for treating refractory HER2-positive breast cancer. Despite its initial clinical efficacy, resistance is unfortunately common, necessitating approaches to improve response. Here, we found that in sensitive cells, T-DM1 induced spindle assembly checkpoint (SAC)-dependent immunogenic cell death (ICD), an immune-priming form of cell death. The payload of T-DM1 mediated ICD by inducing eIF2α phosphorylation, surface exposure of calreticulin, ATP and HMGB1 release, and secretion of ICD-related cytokines, all of which were lost in resistance. Accordingly, ICD-related gene signatures in pretreatment samples correlated with clinical response to T-DM1-containing therapy, and increased infiltration of antitumor CD8+ T cells in posttreatment samples was correlated with better T-DM1 response. Transforming acidic coiled-coil containing 3 (TACC3) was overexpressed in T-DM1-resistant cells, and T-DM1 responsive patients had reduced TACC3 protein expression whereas nonresponders exhibited increased TACC3 expression during T-DM1 treatment. Notably, genetic or pharmacologic inhibition of TACC3 restored T-DM1-induced SAC activation and induction of ICD markers in vitro. Finally, TACC3 inhibition in vivo elicited ICD in a vaccination assay and potentiated the antitumor efficacy of T-DM1 by inducing dendritic cell maturation and enhancing intratumoral infiltration of cytotoxic T cells. Together, these results illustrate that ICD is a key mechanism of action of T-DM1 that is lost in resistance and that targeting TACC3 can restore T-DM1-mediated ICD and overcome resistance.

SIGNIFICANCE

Loss of induction of immunogenic cell death in response to T-DM1 leads to resistance that can be overcome by targeting TACC3, providing an attractive strategy to improve the efficacy of T-DM1.

A method for predicting drugs that can boost the efficacy of immune checkpoint blockade

Combination therapy is a promising therapeutic strategy to enhance the efficacy of immune checkpoint blockade (ICB); however, predicting drugs for effective combination is challenging. Here we developed a general data-driven method called CM-Drug for screening compounds that can boost ICB treatment efficacy based on core and minor gene sets identified between responsive and nonresponsive samples in ICB therapy. The CM-Drug method was validated using melanoma and lung cancer mouse models, with combined therapeutic efficacy demonstrated in eight of nine predicted compounds. Among these compounds, taltirelin had the strongest synergistic effect. Mechanistic analysis and experimental verification demonstrated that taltirelin can stimulate CD8+ T cells and is mediated by the induction of thyroid-stimulating hormone. This study provides an effective and general method for predicting and evaluating drugs for combination therapy and identifies candidate compounds for future ICB combination therapy.

Boosting immune responses in lung tumor immune microenvironment: A comprehensive review of strategies and adjuvants

The immune system has a substantial impact on the growth and expansion of lung malignancies. Immune cells are encompassed by a stroma comprising an extracellular matrix (ECM) and different cells like stromal cells, which are known as the tumor immune microenvironment (TIME). TME is marked by the presence of immunosuppressive factors, which inhibit the function of immune cells and expand tumor growth. In recent years, numerous strategies and adjuvants have been developed to extend immune responses in the TIME, to improve the efficacy of immunotherapy. In this comprehensive review, we outline the present knowledge of immune evasion mechanisms in lung TIME, explain the biology of immune cells and diverse effectors on these components, and discuss various approaches for overcoming suppressive barriers. We highlight the potential of novel adjuvants, including toll-like receptor (TLR) agonists, cytokines, phytochemicals, nanocarriers, and oncolytic viruses, for enhancing immune responses in the TME. Ultimately, we provide a summary of ongoing clinical trials investigating these strategies and adjuvants in lung cancer patients. This review also provides a broad overview of the current state-of-the-art in boosting immune responses in the TIME and highlights the potential of these approaches for improving outcomes in lung cancer patients.

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.

Establishment of an immunogenic cell death-related model for prognostic prediction and identification of therapeutic targets in endometrial carcinoma

OBJECTIVE

Studies have firmly established the pivotal role of the immunogenic cell death (ICD) in the development of tumors. This study seeks to develop a risk model related to ICD to predict the prognosis of patients with endometrial carcinoma (EC).

MATERIALS AND METHODS

RNA-seq data of EC retrieved from TCGA database were analyzed using R software. We determined clusters based on ICD-related genes (ICDRGs) expression levels. Cox and LASSO analyses were further used to build the prediction model, and its accuracy was evaluated in the train and validation sets. Finally, in vitro and in vivo experiments were conducted to confirm the impact of the high-risk gene IFNA2 on EC.

RESULTS

Patients were sorted into two ICD clusters, with survival analysis revealing divergent prognoses between the clusters. The Cox regression analysis identified prognostic risk genes, and the LASSO analysis constructed a model based on 9 of these genes. Notably, this model displayed excellent predictive accuracy when validated. Finally, increased IFNA2 levels led to decreased vitality, proliferation, and invasiveness in vitro. IFNA2 also has significant tumor inhibiting effect in vivo.

CONCLUSIONS

The ICD-related model can accurately predict the prognosis of patients with EC, and IFNA2 may be a potential treatment target.

CRISPR/Cas9-edited ROS1 + non-small cell lung cancer cell lines highlight differential drug sensitivity in 2D vs 3D cultures while reflecting established resistance profiles

INTRODUCTION

The study of resistance-causing mutations in oncogene-driven tumors is fundamental to guide clinical decisions. Several point mutations affecting the ROS1 kinase domain have been identified in the clinical setting, but their impact requires further exploration, particularly in improved pre-clinical models. Given the scarcity of solid pre-clinical models to approach rare cancer subtypes like ROS1 + NSCLC, CRISPR/Cas9 technology allows the introduction of mutations in patient-derived cell lines for which resistant variants are difficult to obtain due to the low prevalence of cases within the clinical setting.

METHODS

In the SLC34A2-ROS1 rearranged NSCLC cell line HCC78, we knocked-in through CRISPR/Cas9 technology three ROS1 drug resistance-causing mutations: G2032R, L2026M and S1986Y. Such variants are located in different functional regions of the ROS1 kinase domain, thus conferring TKI resistance through distinct mechanisms. We then performed pharmacological assays in 2D and 3D to assess the cellular response of the mutant lines to crizotinib, entrectinib, lorlatinib, repotrectinib and ceritinib. In addition, immunoblotting assays were performed in 2D-treated cell lines to determine ROS1 phosphorylation and MAP kinase pathway activity. The area over the curve (AOC) defined by the normalized growth rate (NGR_fit) dose-response curves was the variable used to quantify the cellular response towards TKIs.

RESULTS

Spheroids derived from ROS1G2032R cells were significantly more resistant to repotrectinib (AOC fold change = - 7.33), lorlatinib (AOC fold change = - 6.17), ceritinib (AOC fold change = - 2.8) and entrectinib (AOC fold change = - 2.02) than wild type cells. The same cells cultured as a monolayer reflected the inefficacy of crizotinib (AOC fold change = - 2.35), entrectinib (AOC fold change = - 2.44) and ceritinib (AOC fold change = - 2.12) in targeting the ROS1 G2032R mutation. ROS1L2026M cells showed also remarkable resistance both in monolayer and spheroid culture compared to wild type cells, particularly against repotrectinib (spheroid AOC fold change = - 2.19) and entrectinib (spheroid AOC fold change = - 1.98). ROS1S1986Y cells were resistant only towards crizotinib in 2D (AOC fold change = - 1.86). Overall, spheroids showed an increased TKI sensitivity compared to 2D cultures, where the impact of each mutation that confers TKI resistance could be clearly distinguished. Western blotting assays qualitatively reflected the patterns of response towards TKI observed in 2D culture through the levels of phosphorylated-ROS1. However, we observed a dose-response increase of phosphorylated-Erk1/2, suggesting the involvement of the MAPK pathway in the mediation of apoptosis in HCC78 cells.

CONCLUSION

In this study we knock-in for the first time in a ROS1 + patient-derived cell line, three different known resistance-causing mutations using CRISPR/Cas9 in the endogenous translocated ROS1 alleles. Pharmacological assays performed in 2D and 3D cell culture revealed that spheroids are more sensitive to TKIs than cells cultured as a monolayer. This direct comparison between two culture systems could be done thanks to the implementation of normalized growth rates (NGR) to uniformly quantify drug response between 2D and 3D cell culture. Overall, this study presents the added value of using spheroids and positions lorlatinib and repotrectinib as the most effective TKIs against the studied ROS1 resistance point mutations.

Immunogenic Bifunctional Nanoparticle Suppresses Programmed Cell Death-Ligand 1 in Cancer and Dendritic Cells to Enhance Adaptive Immunity and Chemo-Immunotherapy

Blockade of programmed cell death-1/programmed cell death-ligand 1 (PD-L1) immune checkpoints with monoclonal antibodies has shown great promise for cancer treatment, but these antibodies can cause immune-related adverse events in normal organs. Here we report a dual-cell targeted chemo-immunotherapeutic nanoscale coordination polymer (NCP), OxPt/BP, comprising oxaliplatin (OxPt) and 2-bromopalmitic acid (BP), for effective downregulation of PD-L1 expression in both cancer cells and dendritic cells (DCs) by inhibiting palmitoyl acyltransferase DHHC3. OxPt/BP efficiently promotes DC maturation by increasing intracellular oxidative stress and enhancing OxPt-induced immunostimulatory immunogenic cancer cell death. Systemic administration of OxPt/BP reduces the growth of subcutaneous and orthotopic colorectal carcinoma by facilitating the infiltration and activation of cytotoxic T lymphocytes together with reducing the population of immunosuppressive regulatory T cells. As a result, OxPt/BP significantly extends mouse survival without causing side effects. This work highlights the potential of NCPs in simultaneously reprogramming cancer cells and DCs for potent cancer treatment.

Manipulating calcium homeostasis with nanoplatforms for enhanced cancer therapy

Calcium ions (Ca2+) are indispensable and versatile metal ions that play a pivotal role in regulating cell metabolism, encompassing cell survival, proliferation, migration, and gene expression. Aberrant Ca2+ levels are frequently linked to cell dysfunction and a variety of pathological conditions. Therefore, it is essential to maintain Ca2+ homeostasis to coordinate body function. Disrupting the balance of Ca2+ levels has emerged as a potential therapeutic strategy for various diseases, and there has been extensive research on integrating this approach into nanoplatforms. In this review, the current nanoplatforms that regulate Ca2+ homeostasis for cancer therapy are first discussed, including both direct and indirect approaches to manage Ca2+ overload or inhibit Ca2+ signalling. Then, the applications of these nanoplatforms in targeting different cells to regulate their Ca2+ homeostasis for achieving therapeutic effects in cancer treatment are systematically introduced, including tumour cells and immune cells. Finally, perspectives on the further development of nanoplatforms for regulating Ca2+ homeostasis, identifying scientific limitations and future directions for exploitation are offered.

Phospholipid scramblase 1 is involved in immunogenic cell death and contributes to dendritic cell-based vaccine efficiency to elicit antitumor immune response in vitro

BACKGROUND AIMS

Whole tumor cell lysates (TCLs) obtained from cancer cells previously killed by treatments able to promote immunogenic cell death (ICD) can be efficiently used as a source of tumor-associated antigens for the development of highly efficient dendritic cell (DC)-based vaccines. Herein, the potential role of the interferon (IFN)-inducible protein phospholipid scramblase 1 (PLSCR1) in influencing immunogenic features of dying cancer cells and in enhancing DC-based vaccine efficiency was investigated.

METHODS

PLSCR1 expression was evaluated in different mantle-cell lymphoma (MCL) cell lines following ICD induction by 9-cis-retinoic acid (RA)/IFN-α combination, and commercial kinase inhibitor was used to identify the signaling pathway involved in its upregulation. A Mino cell line ectopically expressing PLSCR1 was generated to investigate the potential involvement of this protein in modulating ICD features. Whole TCLs obtained from Mino overexpressing PLSCR1 were used for DC loading, and loaded DCs were employed for generation of tumor antigen-specific cytotoxic T lymphocytes.

RESULTS

The ICD inducer RA/IFN-α combination promoted PLSCR1 expression through STAT1 activation. PLSCR1 upregulation favored pro-apoptotic effects of RA/IFN-α treatment and enhanced the exposure of calreticulin on cell surface. Moreover, DCs loaded with TCLs obtained from Mino ectopically expressing PLSCR1 elicited in vitro greater T-cell-mediated antitumor responses compared with DCs loaded with TCLs derived from Mino infected with empty vector or the parental cell line. Conversely, PLSCR1 knock-down inhibited the stimulating activity of DCs loaded with RA/IFN-α-treated TCLs to elicit cyclin D1 peptide-specific cytotoxic T lymphocytes.

CONCLUSIONS

Our results indicate that PLSCR1 improved ICD-associated calreticulin exposure induced by RA/IFN-α and was clearly involved in DC-based vaccine efficiency as well, suggesting a potential contribution in the control of pathways associated to DC activation, possibly including those involved in antigen uptake and concomitant antitumor immune response activation.

Celastrol Elicits Antitumor Effects through Inducing Immunogenic Cell Death and Downregulating PD-L1 in ccRCC

BACKGROUND

Targeting immunogenic cell death (ICD) is considered a promising therapeutic strategy for cancer. However, the commonly identified ICD inducers promote the expression of programmed cell death ligand 1 (PD-L1) in tumor cells, thus aiding them to evade the recognition and killing by the immune system. Therefore, the finding of novel ICD inducers to avoid enhanced PD-L1 expression is of vital significance for cancer therapy. Celastrol (CeT), a triterpene isolated from Tripterygium wilfordii Hook. F induces various forms of cell death to exert anti-cancer effects, which may make celastrol an attractive candidate as an inducer of ICD.

METHODS

In the present study, bioinformatics analysis was combined with experimental validation to explore the underlying mechanism by which CeT induces ICD and regulates PD-L1 expression in clear cell renal cell carcinoma (ccRCC).

RESULTS

The results showed that EGFR, IKBKB, PRKCQ and MAPK1 were the crucial targets for CeT-induced ICD, and only MAPK1 was an independent prognostic factor for the overall survival (OS) of ccRCC patients. In addition, CeT triggered autophagy and up-regulated the expressions of HMGB1 and CRT to induce ICD in 786-O cells in vitro. Importantly, CeT can down-regulate PD-L1 expression through activating autophagy. At the molecular level, CeT suppressed PD-L1 via the inhibition of MAPK1 expression. Immunologically, the core target of celastrol, MAPK1, was tightly correlated with CD8+ T cells and CD4+ T cells in ccRCC.

CONCLUSION

These findings indicate that CeT not only induces ICD but also suppresses PD-L1 by down-regulating MAPK1 expression, which will provide an attractive strategy for ccRCC immunotherapy.

Molecular determinants of immunogenic cell death elicited by radiation therapy

Cancer cells undergoing immunogenic cell death (ICD) can initiate adaptive immune responses against dead cell-associated antigens, provided that (1) said antigens are not perfectly covered by central tolerance (antigenicity), (2) cell death occurs along with the emission of immunostimulatory cytokines and damage-associated molecular patterns (DAMPs) that actively engage immune effector mechanisms (adjuvanticity), and (3) the microenvironment of dying cells is permissive for the initiation of adaptive immunity. Finally, ICD-driven immune responses can only operate and exert cytotoxic effector functions if the microenvironment of target cancer cells enables immune cell infiltration and activity. Multiple forms of radiation, including non-ionizing (ultraviolet) and ionizing radiation, elicit bona fide ICD as they increase both the antigenicity and adjuvanticity of dying cancer cells. Here, we review the molecular determinants of ICD as elicited by radiation as we critically discuss strategies to reinforce the immunogenicity of cancer cells succumbing to clinically available radiation strategies.

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.

Microbes mediated immunogenic cell death in cancer immunotherapy

Immunogenic cell death (ICD) is one of the 12 distinct cell death forms, which can trigger immune system to fight against cancer cells. During ICD, a number of cellular changes occur that can stimulate an immune response, including the release of molecules called damage-associated molecular patterns (DAMPs), signaling to immune cells to recognize and attack cancer cells. By virtue of their pivotal role in immune surveillance, ICD-based drug development has been a new approach to explore novel therapeutic combinations and personalized strategies in cancer therapy. Several small molecules and microbes can induce ICD-relevant signals and cause cancer cell death. In this review, we highlighted the role of microbe-mediate ICD in cancer immunotherapy and described the mechanisms through which microbes might serve as ICD inducers in cancer treatment. We also discussed current attempts to combine microbes with chemotherapy regimens or immune checkpoint inhibitors (ICIs) in the treatment of cancer patients. We surmise that manipulation of microbes may guide personalized therapeutic interventions to facilitate anticancer immune response.

Immunogenic Cell Stress and Death Sensitize Tumors to Immunotherapy

The efficacy of chemotherapy with cytotoxicants and that of targeted therapies with more sophisticated agents is limited due to the plasticity of malignant cells, which leads to the inevitable development of resistance [...].