The multifaceted roles and mechanisms of necroptosis in cancer cells remain incompletely understood. Here, we demonstrate that FGFR2 inhibition potently inhibits esophageal squamous cell carcinoma (ESCC) by inducing necroptosis in a RIP1/MLKL-dependent manner and show RIP3 is dispensable in this pathway. Notably, MST1 is identified as a necroptotic pathway component that interacts with RIP1 and MLKL to promote necroptosis by phosphorylating MLKL at Thr216. Additionally, FGFR2 inhibition induces Ser518 phosphorylation and triggers ubiquitin-mediated degradation of NF2, culminating in Hippo pathway suppression. Subsequently, YAP activation promotes RIP1 and MLKL transcriptional upregulation, further amplifying necroptosis. Intriguingly, IL-8 derived from necrotic cells stimulates peripheral surviving tumor cells to increase PD-L1 expression. Dual blockade of FGFR2/PD-L1 or FGFR2/IL-8-CXCR1/2 robustly impedes tumor growth in humanized mouse xenografts. Collectively, our findings delineate an alternative FGFR2-NF2-YAP signaling-dependent necroptotic pathway and shed light on the immunoregulatory role of FGFR2, offering promising avenues for combinatorial therapeutic strategies in clinical cancer management.

Recombinant interferon alpha (IFNα) has been used to treat cancer patients for over 30 years; however, its clinical utility has been limited by a narrow therapeutic index. Given the recognized anti-tumor and immunomodulatory impacts of IFNα, the development of novel strategies to harness these attributes while minimizing associated toxicity could provide significant benefit for patients. The concept of attenuating IFNα binding affinity for its receptor was conceived to address this challenge and led to the development of CD38-targeted Attenukine™, a CD38-targeted antibody attenuated IFNα immunocytokine. In this study, we sought to delineate the effects of targeting AttenukineTM specifically to tumor cells and/or immune cells using an antibody to CD38, a cell surface glycoprotein expressed on certain tumor and immune cells, using different mouse models and anti-human or anti-mouse CD38-targeted Attenukine™. Our results demonstrate that an anti-human CD38 AttenukineTM inhibits tumor growth through direct anti-proliferative effects of IFNα on CD38 + tumor cells as well as by indirectly modulating the anti-tumor immune response. In various in vivo models leveraging syngeneic mice bearing tumors with or without CD38 expression, administration of CD38-murine AttenukineTM mediated anti-tumor efficacy with increased immune activation and intra-tumoral infiltration. These data point to a potential dual mechanism of action for CD38-targeted Attenukine™, involving both tumor- and immune-directed effects, and highlight the potential benefit of a CD38-targeted attenuated IFNα therapy to deliver the known effects of IFNαtreatment to a broad spectrum of patients, while limiting the toxicity typically associated with recombinant IFNα.

Receptor-interacting protein kinase-3 is essential for the cell death pathway called necroptosis. Necroptosis is activated by the death receptor ligands and pattern recognition receptors of the innate immune system, leading to significant consequences in inflammation and in diseases, particularly cancer. Necroptosis is highly proinflammatory compared with other modes of cell death because cell membrane integrity is lost, resulting in releases of cytokines and damage-associated molecular patterns that potentiate inflammation and activate the immune system. We discuss various ways that necroptosis is triggered along with its potential role in cancer and therapy.

PANoptosis, a newly identified form of programmed cell death regulated by the panoptosome complex, exhibits key characteristics of apoptosis, pyroptosis and necroptosis. It exerts a substantial influence on the initiation and progression of a spectrum of diseases, particularly in cancer, where its impact is increasingly being recognized. PANoptosis is closely related to tumorigenesis, carcinogenesis, metastasis, chemotherapy resistance, as well as the prediction of therapeutic responses and prognosis in cancer patients. In this review, we first review the discovery of PANoptosis and systematically analyze the composition of the panoptosome. Subsequently, we examine the role of PANoptosis in various types of cancer, encompassing its function within the tumor microenvironment, its role in tumor drug resistance, and its predictive role in cancer prognosis. Ultimately, we delve into strategies for targeting PANoptosis in cancer therapy, including targeting various molecules in the PANoptosis pathway, such as ZBP1, RIPK1, RIPK3, Caspases and other novel strategies like nanoinducers and viral vectors. This review aims to provide references and assistance for the research and application of PANoptosis in cancer treatment.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense, immunosuppressive tumor microenvironment (TME) that limits therapeutic efficacy. This study investigates the role of cellular communication network factor 1 (CCN1, also known as Cyr61), an extracellular matrix-associated protein, in modulating the TME of PDAC. It is demonstrated that Ccn1 promotes PDAC progression by upregulating collagen and chemokine expression, thereby facilitating immune cell exclusion and enhancing tumor growth. Using a Ccn1-deficient PDAC model, decreased collagen and chemokine levels are observed, resulting in increased infiltration of cytotoxic immune cells and reduced myeloid-derived suppressor cells (MDSCs). Furthermore, Ccn1-deficient tumors exhibit heightened sensitivity to gemcitabine and show enhanced responsiveness to anti-programmed cell death 1 (anti-PD1) therapy. Mechanistically, Ccn1 regulates chemokine production through collagen expression, with chemokine levels remaining suppressed even upon interferon-gamma treatment in collagen-deficient cells. These findings highlight Ccn1 as a potential therapeutic target that reprograms the TME to enhance the efficacy of both chemotherapy and immunotherapy in PDAC, providing a novel approach for overcoming immune resistance in PDAC.

Receptor-interacting protein kinase 1 (RIPK1) serves as a critical mediator of cell necroptosis and represents a promising therapeutic target for various human neurodegenerative diseases and inflammatory diseases. Nonetheless, the RIPK1 inhibitors currently reported are inadequate for clinical research due to suboptimal inhibitory activities or lack of selectivity. Consequently, there is a need for the discovery of novel RIPK1 kinase inhibitors. In this study, we integrated a deep learning model, specifically the fingerprint graph attention network (FP-GAT), with molecular docking-based virtual screening to identify potential RIPK1 inhibitors from a library comprising 13 million compounds. Out of 43 compounds procured, two compounds (designated as 24 and 41) demonstrated enzyme inhibition activity exceeding 50% at a concentration of 10 μM against RIPK1. The half-maximal inhibitory concentrations (IC50) for compounds 24 and 41 were determined to be 2.01 and 2.95 μM, respectively. Furthermore, these compounds exhibited protective effects in an HT-29 cell model of TSZ-induced necroptosis, with half-maximal effective concentrations (EC50) of 6.77 μM for compound 24 and 68.70 μM for compound 41. Finally, molecular dynamics simulations and binding free energy calculations were conducted to elucidate the molecular mechanism of compounds 24 and 41 binding to RIPK1. The results show that Met92, Met95, Ala155, and Asp156 are key residues for novel RIPK1 inhibitors. In summary, this work discovered two hit compounds targeting RIPK1, which can be further structurally modified to become promising lead compounds.

Neoantigen vaccines are among the most potent immunotherapies for personalized cancer treatment. Therapeutic vaccines containing tumor-specific neoantigens that elicit specific T cell responses offer the potential for long-term clinical benefits to cancer patients. Unlike immune-checkpoint inhibitors (ICIs), which rely on pre-existing specific T cell responses, personalized neoantigen vaccines not only promote existing specific T cell responses but importantly stimulate the generation of neoantigen-specific T cells, leading to the establishment of a persistent specific memory T cell pool. The review discusses the current state of clinical research on neoantigen nanovaccines, focusing on the application of vectors, adjuvants, and combinational strategies to address a range of challenges and optimize therapeutic outcomes.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motor neuron loss. Microglia and astrocyte-driven neuroinflammation is prominent in ALS, but the cell state dynamics and pathways driving disease remain unclear. We performed single-nucleus RNA sequencing of ALS spinal cords and identified altered glial cell states, including increased expression of inflammatory and glial activation markers. Many of these signals converged on the inflammation and cell death regulator receptor-interacting protein kinase 1 (RIPK1) and the necroptotic cell death pathway. In superoxide dismutase 1 (SOD1)G93A mice, blocking RIPK1 kinase activity delayed symptom onset and motor impairment and modulated glial responses. We used human induced pluripotent stem cell (iPSC)-derived motor neuron, astrocyte, and microglia tri-cultures to identify potential biomarkers that are secreted upon RIPK1 activation in vitro and modulated by RIPK1 inhibition in the cerebrospinal fluid (CSF) of people with ALS. These data reveal ALS-enriched glial populations associated with inflammation and suggest a deleterious role for neuroinflammatory signaling in ALS pathogenesis.

CCCTC-binding factor (CTCF) regulates chromatin organization and is upregulated in pancreatic ductal adenocarcinoma (PDAC). We found that CTCF interacts with HNRNPU through a FLG-AS1-dependent mechanism, facilitating the recruitment of EP300 and activation of the m6A reader IGF2BP2. This activation promotes histone lactylation at the promoter region of IGF2BP2 stimulating the proliferation of PDAC cells. IGF2BP2 enhanced the mRNA stability of CSF1 and MYC. Moreover, FLG-AS1 directly interacts with HNRNPU to modulate alternative splicing of CSF1, thus promoting the M2 polarization of tumor associated macrophages (TAMs) in PDAC. The results indicated that CTCF-induced oncogenic modification of histone lactylation, m6A and alternative spilcing as multi-regulation modes of TAMs reprogramming in PDAC and identifies CTCF as a potential therapeutic target for PDAC immunotherapy whose inhibition M2 polarization through the IGF2BP2/CSF1/CSF1R axis. Curaxin combined with gemcitabine treatment has shown promising antitumor efficacy against PDAC.

Myeloid cells play a crucial dual role in cancer progression and response to therapy, promoting tumor growth, enabling immune suppression, and contributing to metastatic spread. The ability of these cells to modulate the immune system has made them attractive targets for therapeutic strategies aimed at shifting their function from tumor promotion to fostering antitumor immunity. Therapeutic approaches targeting myeloid cells focus on modifying their numbers, genetics, metabolism, and interactions within the tumor microenvironment. These strategies aim to reverse their suppressive functions and redirect them to support antitumor immune responses by inhibiting immunosuppressive pathways, targeting specific receptors, and promoting their differentiation into less immunosuppressive phenotypes. Here, we discuss recent approaches to clinically target tumor myeloid cells, focusing on reprogramming myeloid cells to promote antitumor immunity.

CXCR1/2 inhibitors are being implemented with immunotherapies in PDAC clinical trials. CXC-ligands are a family of cytokines responsible for stimulating these receptors; while typically secreted by activated immune cells, fibroblasts, and even adipocytes, they are also secreted by immune-evasive cancer cells. CXC-ligand release is known to occur in response to inflammatory stimuli. Adipose tissue is an endocrine organ and a source of inflammatory signaling peptides. Importantly, adipose-derived cytokines and chemokines are implicated as potential drivers of tumor cell immune evasion; cumulatively, these findings suggest that targeting CXC-ligands may be beneficial in the context of obesity.

RNA-sequencing of human PDAC cell lines was used to assess influences of adipose conditioned media on the cancer cell transcriptome. The adipose-induced secretome of PDAC cells was validated with ELISA for induction of CXCL5 secretion. Human tissue data from CPTAC was used to correlate IL-1β and TNF expression with both CXCL5 mRNA and protein levels. CRISPR-Cas9 was used to knockout CXCL5 from a murine PDAC KPC cell line to assess orthotopic tumor studies in syngeneic, diet-induced obese mice. Flow cytometry and immunohistochemistry were used to compare the immune profiles between tumors with or without CXCL5. Mice-bearing CXCL5 competent or deficient tumors were monitored for differential tumor size in response to anti-PD-1 immune checkpoint blockade therapy.

Human adipose tissue conditioned media stimulates CXCL5 secretion from PDAC cells via either IL-1β or TNF; neutralization of both is required to significantly block the release of CXCL5 from tumor cells. Ablation of CXCL5 from tumors promoted an enriched immune phenotype with an unanticipatedly increased number of exhausted CD8 T cells. Application of anti-PD-1 treatment to control tumors failed to alter tumor growth, yet treatment of CXCL5-deficient tumors showed response by significantly diminished tumor mass.

In summary, our findings show that both TNF and IL-1β can stimulate CXCL5 release from PDAC cells in vitro, which correlates with expression in patient data. CXCL5 depletion in vivo alone is sufficient to promote T cell infiltration into tumors, increasing efficacy and requiring checkpoint blockade inhibition to alleviate tumor burden.

Necroptosis is a programmed form of cell death. Receptor-interacting serine/threonine protein kinase l (RIPK1) is a crucial protein kinase that regulates the necroptosis pathway. Increased expression of death receptor family ligands such as tumor necrosis factor (TNF) increases the susceptibility of cells to apoptosis and necroptosis. RIPK1, RIPK3, and mixed-lineage kinase-like domain (MLKL) proteins mediate necrosis. RIPK1-mediated necroptosis further promotes cell death and inflammation in the pathogenesis of liver injury, skin diseases, and neurodegenerative diseases. The N-terminal kinase domain of RIPK1 is significant in the induction of cell death and can be used as a vital drug target for inhibitors. In this paper, we outline the pathways of necroptosis and the role RIPK1 plays in them and suggest that targeting RIPK1 in therapy may help to inhibit multiple cell death pathways.

Pancreatic ductal adenocarcinoma (PDAC) poses a grim prognosis for patients. Recent multidisciplinary research efforts have provided critical insights into its genetics and tumor biology, creating the foundation for rational development of targeted and immune therapies. Here, we review the PDAC genomic landscape and the role of specific oncogenic events in tumor initiation and progression, as well as their contributions to shaping its tumor biology. We further summarize and synthesize breakthroughs in single-cell and metabolic profiling technologies that have illuminated the complex cellular composition and heterotypic interactions of the PDAC tumor microenvironment, with an emphasis on metabolic cross-talk across cancer and stromal cells that sustains anabolic growth and suppresses tumor immunity. These conceptual advances have generated novel immunotherapy regimens, particularly cancer vaccines, which are now in clinical testing. We also highlight the advent of KRAS targeted therapy, a milestone advance that has transformed treatment paradigms and offers a platform for combined immunotherapy and targeted strategies. This review provides a perspective summarizing current scientific and therapeutic challenges as well as practice-changing opportunities for the PDAC field at this major inflection point.

Pancreatic cancer remains one of the most lethal forms of cancer. Currently, there is a lack of effective drug treatments for pancreatic cancer. However, as a newly discovered form of non-apoptotic cell death, ferroptosis has garnered increasing attention in relation to pancreatic cancer. Understanding the role of ferroptosis in the tumorigenesis and treatment of pancreatic cancer may enable more effective clinical trials and treatments for pancreatic cancer and may minimize side effects or restrict the emergence of drug resistance. In this review, we summarize the current knowledge regarding the process and underlying mechanisms of ferroptosis, as well as its dual role in both promoting tumorigenesis and facilitating treatment strategies for pancreatic cancer. Additionally, how ferroptosis is implicated in the development of pancreatitis and insulin resistance, indicating that ferroptosis may play an important role in the risk of pancreatitis- and insulin-resistance-related pancreatic cancers, is also addressed.

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) regulates programmed cell death and inflammation, contributing to a wide range of human pathologies, including inflammatory disorders, neurodegenerative conditions, and cancer. Despite this, no RIPK1 positron emission tomography (PET) ligand with significant in vivo specificity has been reported to date. In this work, we designed and synthesized a new family of dihydropyrazole-cored ligands suitable for 18F-labeling at the late stage. Among these, WL8 showed a strong binding affinity to RIPK1 (EC50 = 19.9 nM, Kd = 25 nM) and was successfully labeled with 18F in the 6-position of pyridine ring, yielding a high radiochemistry yield of 27.9 % (decay-corrected) and a high molar activity of 18.8-31.2 GBq/μmol. In in vitro autoradiography, [18F]WL8 showed some specific binding in the brain sections of rats and lipopolysaccharide (LPS) model mice. Preliminary PET studies in rat brains revealed that [18F]WL8 could efficiently penetrate the blood-brain barrier and was rapidly washed out. As anticipated, [18F]WL8 exhibited a high initial uptake (brain2min = 4.80 % ID/g) in mouse brains, followed by a rapid washout (brain60min = 0.14 % ID/g), although no clear specific binding to RIPK1 was observed. Moderate in vivo stability was noted for [18F]WL8 in mouse brains with 35.2 % of the parent fraction remaining after 30 min post-administration. Altogether, our work broadens the landscape and offers a new chemotype for RIPK1 PET ligand development.

Tumor-associated macrophages (TAMs) play a pivotal role in sculpting the tumor microenvironment and influencing cancer progression, particularly through their interactions with various forms of regulated cell death (RCD), including apoptosis, pyroptosis, ferroptosis, and necroptosis. This review examines the interplay between TAMs and these RCD pathways, exploring the mechanisms through which they interact to promote tumor growth and advancement. We examine the underlying mechanisms of these intricate interactions, emphasizing their importance in cancer progression and treatment. Moreover, we present potential therapeutic strategies for targeting TAMs and manipulating RCD to enhance anti-tumor responses. These strategies encompass reprogramming TAMs, inhibiting their recruitment, and selectively eliminating them to enhance anti-tumor functions, alongside modulating RCD pathways to amplify immune responses. These insights offer a novel perspective on tumor biology and provide a foundation for the development of more efficacious cancer therapies.

U2AF homology motif kinase 1 (UHMK1) is a newly discovered molecule that may have multiple functions. Recent studies have revealed that UHMK1 had aberrant expression in many tumors and was associated with tumor progression. However, UHMK1 was rarely reported in oral squamous cell carcinoma (OSCC).

In this study, Western blot, quantitative real-time polymerase chain reaction (PCR), and immunohistochemistry were used to detect the expression of UHMK1 in OSCC and peritumoral non-neoplastic tissues. Then, its relationship with clinicopathologic parameters was analyzed. The Kaplan-Meier method and Cox regression model were used to analyze the effects of UHMK1 expression on the prognosis and survival of OSCC patients.

Our results showed that UHMK1 had higher expression in OSCC tissues compared with in peritumoral non-neoplastic tissues, and its high expression was associated with high TNM stage and lymph node metastasis. High UHMK1 expression was related to short overall and disease-free survival times. Moreover, UHMK1 expression was identified as an independent prognostic factor that influences overall and disease-free survival of OSCC patients.

High expression of UHMK1 is associated with the poor prognosis of patients, and it can be used as a potential prognostic molecule for OSCC.

Interleukin‑17 (IL‑17), an inflammatory cytokine primarily secreted by T helper 17 cells, serves a crucial role in numerous inflammatory diseases and malignancies via its receptor, IL‑17R. In addition to stimulating inflammatory responses, IL‑17 exhibits dual functions in tumors, exerting both pro‑ and antitumor effects. Pancreatic ductal adenocarcinoma (PDAC) is the most common pancreatic malignancy and accounts for >90% of pancreatic cancer cases. PDAC is characterized by a prominent stromal microenvironment with significant heterogeneity, which contributes to treatment resistance. IL‑17/IL‑17R signaling has a notable effect on tumorigenesis, the tumor microenvironment and treatment efficacy in various cancer types, including PDAC. However, the specific mechanisms of IL‑17/IL‑17R signaling in pancreatic cancer remain uncertain. This review presents a brief overview of the current knowledge and recent advances in the role and functional mechanisms of IL‑17/IL‑17R signaling in pancreatic cancer. Furthermore, the potential of IL‑17‑targeted therapeutic strategies for PDAC treatment is also discussed.

HER2+ breast tumors have abundant immune-suppressive cells, including M2-type tumor-associated macrophages (TAMs). Although TAMs consist of the immune-stimulatory M1 type and immune-suppressive M2 type, the M1/M2-TAM ratio is reduced in immune-suppressive tumors, contributing to their immunotherapy refractoriness. M1- versus M2-TAM formation depends on differential arginine metabolism, where M1-TAMs convert arginine to nitric oxide (NO) and M2-TAMs convert arginine to polyamines (PAs). We hypothesize that such distinct arginine metabolism in M1- versus M2-TAMs is attributed to different availability of BH4 (NO synthase cofactor) and that its replenishment would reprogram M2-TAMs to M1-TAMs. Recently, we reported that sepiapterin (SEP), the endogenous BH4 precursor, elevates the expression of M1-TAM markers within HER2+ tumors. Here, we show that SEP restores BH4 levels in M2-like macrophages, which then redirects arginine metabolism to NO synthesis and converts M2 type to M1 type. The reprogrammed macrophages exhibit full-fledged capabilities of antigen presentation and induction of effector T cells to trigger immunogenic cell death of HER2+ cancer cells. This study substantiates the utility of SEP in the metabolic shift of the HER2+ breast tumor microenvironment as a novel immunotherapeutic strategy.

Pancreatic cancer (PC) is one of the most lethal malignancies and new therapeutic strategies are urgently needed. β1,3-N-acetylglucosaminyltransferase V (B3GNT5) may be a potential option for cancer treatment, but its role in PC remains unknown. In this study, we first demonstrated through bioinformatics analysis that B3GNT5 was high expression in PC and predicted poor prognosis. We further constructed B3GNT5 overexpression or knockdown cell lines by employing lentivirus packaging techniques and confirmed that B3GNT5 could promote tumor cell viability and autonomous growth using cultured cells and vivo xenograft models. In addition, we found that knockdown of B3GNT5 in PC cells inhibited cell migration, invasion, and angiogenesis, as well as stemness of cancer stem cells and enhanced chemotherapy sensitivity to gemcitabine. Mechanistically, overexpression of the transcription factor STAT5B in PC cells enhanced the transcriptional activity of the B3GNT5 promoter. Our work confirmed a tumor-promotive role of B3GNT5 in PC pathogenesis.

Although gemcitabine (GEM) is the first‑line drug for advanced pancreatic adenocarcinoma (PAAD), the development of GEM resistance severely limits the effectiveness of this chemotherapy. This study investigated the mechanisms of ecotropic viral integration site 2 A (EVI2A) for resistance to GEM and immune evasion in PAAD. GEM resistance-related biomarkers were predicted using GEO datasets, and GEM-resistant PAAD cells were generated. EVI2A was found expressed highly in GEM-resistant PAAD cells. Gain-of-function analyses revealed that EVI2A encouraged the proliferation and motility of GEM-resistant cells and prevented apoptosis. In addition, EVI2A reduced T cell effector activation. SMYD2 was overexpressed in GEM-resistant cells, and SMYD2 enhanced H3K36me2 modification of EVI2A, thereby promoting EVI2A expression. SMYD2 reduced the sensitivity of GEM-resistant cells, which was reversed by EVI2A knockdown. SMYD2 increased the amount of M2 macrophages (co-cultured with PAAD cells) and decreased T cell effector activation (co-cultured with macrophage supernatant), and the number of M2 macrophages was decreased and T cell effectors were activated following EVI2A knockdown. Our findings indicate that EVI2A, manipulated by the SMYD2-H3K36me2 epigenetic axis, promoted GEM resistance and M2 macrophage-mediated immune evasion in PAAD. Therefore, EVI2A might represent a therapeutic target for overcoming GEM resistance and immunosuppressive environment in PAAD.

Receptor-interacting serine/threonine protein kinase 1 (RIPK1) has emerged as an important regulator of pathologic cell death and inflammation and is implicated in the pathologies of various central nervous system diseases. In this study, we reported the development of three potent dihydropyrazole-cored RIPK1 positron emission tomography (PET) ligands [18F]WL1-3. Among these, [18F]WL1 showed specific binding to RIPK1 in mouse brain sections in vitro through autoradiography and exhibited favorable brain kinetics in mice, characterized by a high initial uptake (brain2 min = 4.89% ID/g) and rapid washout (brain60 min = 0.21% ID/g). PET studies in rat brains revealed that [18F]WL1 could readily penetrate the brain with specific binding confirmed by inhibition effects of unlabeled WL1 and GSK'547. Notably, [18F]WL1 showed significant potential in imaging the alterations of RIPK1 in a rat brain of tumor necrosis factor α-induced systemic inflammatory response syndrome model. These findings may pave the way for the future design of potent RIPK1 PET ligands.

Pancreatic ductal adenocarcinoma (PDAC) presents a fatal clinical challenge characterized by a dismal 5-year overall survival rate, primarily due to the lack of early diagnosis and limited therapeutic efficacy. Immunotherapy, a proven success in multiple cancers, has yet to demonstrate significant benefits in PDAC. Recent studies have revealed the immunosuppressive characteristics of the PDAC tumor microenvironment (TME), including immune cells with suppressive properties, desmoplastic stroma, microbiome influences, and PDAC-specific signaling pathways. In this article, we review recent advances in understanding the immunosuppressive TME of PDAC, TME differences among various mouse models of pancreatic cancer, and the mechanisms underlying resistance to immunotherapeutic interventions. Furthermore, we discuss the potential of targeting cancer cell-intrinsic pathways and TME components to sensitize PDAC to immune therapies, providing insights into strategies and future perspectives to break through the barriers in improving pancreatic cancer treatment.

Programmed cell death (PCD) is essential for cellular homeostasis and defense against infections, with inflammatory forms like pyroptosis and necroptosis playing significant roles in cancer. Pyroptosis, mediated by caspases and gasdermin proteins, leads to cell lysis and inflammatory cytokine release. It has been implicated in various diseases, including cancer, where it can either suppress tumor growth or promote tumor progression through chronic inflammation. Necroptosis, involving RIPK1, RIPK3, and MLKL, serves as a backup mechanism when apoptosis is inhibited. In cancer, necroptosis can enhance immune responses or contribute to tumor progression. Both pathways have dual roles in cancer, acting as tumor suppressors or promoting a pro-tumorigenic environment depending on the context. This review explores the molecular mechanisms of pyroptosis and necroptosis, their roles in different cancers, and their potential as therapeutic targets. Understanding the context-dependent effects of these pathways is crucial for developing effective cancer therapies.

Protein kinases act as central molecular switches in the control of cellular functions. Alterations in the regulation and function of protein kinases may provoke diseases including cancer. In this study we investigate the conformational states of such disease-associated kinases using the high sensitivity of the kinase conformation (KinCon) reporter system. We first track BRAF kinase activity conformational changes upon melanoma drug binding. Second, we also use the KinCon reporter technology to examine the impact of regulatory protein interactions on LKB1 kinase tumor suppressor functions. Third, we explore the conformational dynamics of RIP kinases in response to TNF pathway activation and small molecule interactions. Finally, we show that CDK4/6 interactions with regulatory proteins alter conformations which remain unaffected in the presence of clinically applied inhibitors. Apart from its predictive value, the KinCon technology helps to identify cellular factors that impact drug efficacies. The understanding of the structural dynamics of full-length protein kinases when interacting with small molecule inhibitors or regulatory proteins is crucial for designing more effective therapeutic strategies.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer with dismal prognosis due to distant metastasis, even in the early stage. Using RNA sequencing and multiplex immunofluorescence, here we find elevated expression of mixed lineage kinase domain-like pseudo-kinase (MLKL) and enhanced necroptosis pathway in PDAC from early liver metastasis T-stage (T1M1) patients comparing with non-metastatic (T1M0) patients. Mechanistically, MLKL-driven necroptosis recruits macrophages, enhances the tumor CD47 'don't eat me' signal, and induces macrophage extracellular traps (MET) formation for CXCL8 activation. CXCL8 further initiates epithelial-mesenchymal transition (EMT) and upregulates ICAM-1 expression to promote endothelial adhesion. METs also degrades extracellular matrix, that eventually supports PDAC liver metastasis. Meanwhile, targeting necroptosis and CD47 reduces liver metastasis in vivo. Our study thus reveals that necroptosis facilitates PDAC metastasis by evading immune surveillance, and also suggest that CD47 blockade, combined with MLKL inhibitor GW806742X, may be a promising neoadjuvant immunotherapy for overcoming the T1M1 dilemma and reviving the opportunity for radical surgery.

This comprehensive review explores the intricate mechanisms of PANoptosis and its implications in cancer. PANoptosis, a convergence of apoptosis, pyroptosis, and necroptosis, plays a crucial role in cell death and immune response regulation. The study delves into the molecular pathways of each cell death mechanism and their crosstalk within PANoptosis, emphasizing the shared components like caspases and the PANoptosome complex. It highlights the significant role of PANoptosis in various cancers, including respiratory, digestive, genitourinary, gliomas, and breast cancers, showing its impact on tumorigenesis and patient survival rates. We further discuss the interwoven relationship between PANoptosis and the tumor microenvironment (TME), illustrating how PANoptosis influences immune cell behavior and tumor progression. It underscores the dynamic interplay between tumors and their microenvironments, focusing on the roles of different immune cells and their interactions with cancer cells. Moreover, the review presents new breakthroughs in cancer therapy, emphasizing the potential of targeting PANoptosis to enhance anti-tumor immunity. It outlines various strategies to manipulate PANoptosis pathways for therapeutic purposes, such as targeting key signaling molecules like caspases, NLRP3, RIPK1, and RIPK3. The potential of novel treatments like immunogenic PANoptosis-initiated therapies and nanoparticle-based strategies is also explored.

RIPK1 inhibitors have emerged as promising candidates for treating diverse diseases, including inflammatory diseases, autoimmune disorders, Alzheimer's disease, and cancer. However, the previously reported binding assays have limited sensitivity and stability, impeding high-throughput screening and robust characterization of the RIPK1 inhibitors. To address this challenge, we introduced two probes, T2-BDP-FL and T3-BDP-FL, derived from distinct RIPK1 inhibitors with different binding modes to establish time-resolved fluorescence resonance energy transfer (TR-FRET) displacement assays. Employing our TR-FRET displacement assays, we quantified the biochemical binding affinities of a series of RIPK1 inhibitors with diverse structural and binding modes for human RIPK1. Consistent results were obtained with these two probes in the TR-FRET displacement assay. Furthermore, we developed a RIPK1 fluorescent probe, T2-BDP589, for the NanoBRET assay. This assay enabled the characterization of RIPK1 target engagement by various RIPK1 inhibitors for both human and mouse RIPK1 in live cells. Our developed fluorescent probe displacement assays offer a sensitive and high-throughput approach to identify RIPK1 inhibitors based on both biochemical and cellular activities.

Biological nanoparticles, or bionanoparticles, are small molecules manufactured in living systems with complex production and assembly machinery. The products of the assembly systems can be further engineered to generate functionalities for specific purposes. These bionanoparticles have demonstrated advantages such as immune system evasion, minimal toxicity, biocompatibility, and biological clearance. Hence, bionanoparticles are considered the new paradigm in nanoscience research for fabricating safe and effective nanoformulations for therapeutic purposes. Harnessing the power of the immune system to recognize and eradicate malignancies is a viable strategy to achieve better therapeutic outcomes with long-term protection from disease recurrence. However, cancerous tissues have evolved to become invisible to immune recognition and to transform the tumor microenvironment into an immunosuppressive dwelling, thwarting the immune defense systems and creating a hospitable atmosphere for cancer growth and progression. Thus, it is pertinent that efforts in fabricating nanoformulations for immunomodulation are mindful of the tumor-induced immune aberrations that could render cancer nanotherapy inoperable. This review systematically categorizes the immunosuppression mechanisms, the regulatory immunosuppressive cellular players, and critical suppressive molecules currently targeted as breakthrough therapies in the clinic. Finally, this review will summarize the engineering strategies for affording immune moderating functions to bionanoparticles that tip the tumor microenvironment (TME) balance toward cancer elimination, a field still in the nascent stage.

In the tumor microenvironment (TME), myeloid cells play a pivotal role. Myeloid-derived immunosuppressive cells, including tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), are central components in shaping the immunosuppressive milieu of the tumor. Within the TME, a majority of TAMs assume an M2 phenotype, characterized by their pro-tumoral activity. These cells promote tumor cell growth, angiogenesis, invasion, and migration. In contrast, M1 macrophages, under appropriate activation conditions, exhibit cytotoxic capabilities against cancer cells. However, an excessive M1 response may lead to pro-tumoral inflammation. As a result, myeloid cells have emerged as crucial targets in cancer therapy. This review concentrates on gastrointestinal tumors, detailing methods for targeting macrophages to enhance tumor radiotherapy and immunotherapy sensitivity. We specifically delve into monocytes and tumor-associated macrophages' various functions, establishing an immunosuppressive microenvironment, promoting tumorigenic inflammation, and fostering neovascularization and stromal remodeling. Additionally, we examine combination therapeutic strategies.

Hepatocellular carcinoma (HCC), one of the leading causes of cancer‑related mortality worldwide, is challenging to identify in its early stages and prone to metastasis, and the prognosis of patients with this disease is poor. Treatment options for HCC are limited, with even radical treatments being associated with a risk of recurrence or transformation in the short term. Furthermore, the multi‑tyrosine kinase inhibitors approved for first‑line therapy have marked drawbacks, including drug resistance and side effects. The rise and breakthrough of immune checkpoint inhibitors (ICIs) have provided a novel direction for HCC immunotherapy but these have the drawback of low response rates. Since avoiding apoptosis is a universal feature of cancer, the induction of non‑apoptotic regulatory cell death (NARCD) is a novel strategy for HCC immunotherapy. At present, NARCD pathways, including ferroptosis, pyroptosis and necroptosis, are novel potential forms of immunogenic cell death, which have synergistic effects with antitumor immunity, transforming immune 'cold' tumors into immune 'hot' tumors and exerting antitumor effects. Therefore, these pathways may be targeted as a novel treatment strategy for HCC. In the present review, the roles of ferroptosis, pyroptosis and necroptosis in antitumor immunity in HCC are discussed, and the relevant targets and signaling pathways, and the current status of combined therapy with ICIs are summarized. The prospects of targeting ferroptosis, pyroptosis and necroptosis in HCC immunotherapy are also considered.

Mosquitoes transmit many disease-relevant flaviviruses. Efficient viral transmission to mammalian hosts requires mosquito salivary factors. However, the specific salivary components facilitating viral transmission and their mechanisms of action remain largely unknown. Here, we show that a female mosquito salivary gland-specific protein, here named A. aegypti Neutrophil Recruitment Protein (AaNRP), facilitates the transmission of Zika and dengue viruses. AaNRP promotes a rapid influx of neutrophils, followed by virus-susceptible myeloid cells toward mosquito bite sites, which facilitates establishment of local infection and systemic dissemination. Mechanistically, AaNRP engages TLR1 and TLR4 of skin-resident macrophages and activates MyD88-dependent NF-κB signaling to induce the expression of neutrophil chemoattractants. Inhibition of MyD88-NF-κB signaling with the dietary phytochemical resveratrol reduces AaNRP-mediated enhancement of flavivirus transmission by mosquitoes. These findings exemplify how salivary components can aid viral transmission, and suggest a potential prophylactic target.

Tumour immune microenvironment (TIME) plays an indispensable role in tumour progression, and tumour-associated macrophages (TAMs) are the most abundant immune cells in TIME. Non-apoptotic regulated cell death (RCD) can avoid the influence of tumour apoptosis resistance on anti-tumour immune response. Specifically, autophagy, ferroptosis, pyroptosis and necroptosis mediate the crosstalk between TAMs and tumour cells in TIME, thus reprogram TIME and affect the progress of tumour. In addition, although some achievements have been made in immune checkpoint inhibitors (ICIs), there is still defect that ICIs are only effective for some people because non-apoptotic RCD can bypass the apoptosis resistance of tumour. As a result, ICIs combined with targeting non-apoptotic RCD may be a promising solution. In this paper, the basic molecular mechanism of non-apoptotic RCD, the way in which non-apoptotic RCD mediates crosstalk between TAMs and tumour cells to reprogram TIME, and the latest research progress in targeting non-apoptotic RCD and ICIs are reviewed.