Death Receptor Research Articles

Mild hyperthermia upregulates PD-L1 in the tumor microenvironment and enhances antitumor efficacy of PD-L1 blockade in murine squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) has a low five-year survival rate because of its high rate of recurrence and metastasis. After surgical resection or radiation, the main treatments for HNSCC, patients sometimes experience functional or aesthetic disorders. Therefore, there is a great demand for the development of non-surgical treatment strategies to improve clinical outcomes and patients' quality of life. One such non-surgical treatment is mild hyperthermia (mHT). Many studies have investigated combination treatments with mHT and immune checkpoint inhibitors in preclinical settings. However, there have been no detailed reports on the effects of mHT on immune checkpoint molecules. Here, we investigated the effects of mHT on the tumor microenvironment (TME), particularly on programmed cell death receptor-1 (PD-1)/programmed cell death ligand-1 (PD-L1), in SCCVII cells and a squamous cell carcinoma mouse model. First, we found that PD-L1 mRNA levels and surface PD-L1 expression significantly increased after mHT. Second, a single tumor model was used to determine the effect of HT on the TME. mHT enhanced the accumulation of CD4+ and CD8+ T cells, elevated PD-L1 expression in the TME, and decreased the PD-1 positive rate of CD4+ T cells. Finally, using a bilateral tumor model, we found that anti-PD-L1 monotherapy and combination therapy resulted in longer survival than the isotype control or mHT monotherapy. Moreover, the combination therapy resulted in a significantly higher survival rate than anti-PD-L1 monotherapy. In conclusion, our findings elucidate changes in PD-L1 expression in the TME and strengthen the rationale for mHT and PD-L1 blockade combination therapy.

Analysis of efficacy and safety for the combination of tislelizumab and regorafenib in advanced hepatocellular carcinoma: A prospective clinical study.

Programmed death receptor 1 (PD-1) monoclonal antibody has been approved for the first and second-line treatments of hepatocellular carcinoma (HCC). This study aimed to evaluate the efficacy and safety of tislelizumab + regorafenib as a second-line treatment option for advanced HCC. Treatment-related adverse events (TRAEs) were the primary endpoints in this clinical trial comprising 28 patients with advanced HCC. The secondary endpoints included objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). According to the mRECIST 1.1 evaluation criteria, the ORR was 28.6%. Complete and partial response were observed in 3 and 5 patients, respectively; stable disease was observed in 12 patients (DCR, 71.4%). The median PFS was 6.4 months. The incidence of grade 1-2 and 3-4 TRAEs was 57.1% and 39.3%, respectively. This study suggests that tislelizumab + regorafenib can be used as a second-line treatment for advanced HCC.

CircRAPGEF5 acts as a modulator of RAS/RAF/MEK/ERK signaling during colorectal carcinogenesis

Mutations in oncogenes such as KRAS, NRAS and BRAF promote the growth and survival of tumors, while excessive RAS/RAF/MEK/ERK activation inhibits tumor growth. In this study we examined the precise regulatory machinery that maintains a moderate RAS/RAF/MEK/ERK pathway activation during CRC. Here, using bioinformatic analysis, transcriptomic profiling, gene silencing and cellular assays we discovered that a circular RNA, circRAPGEF5, is significantly upregulated in KRAS mutant colorectal cancer (CRC) cells. CircRAPGEF5 suppressed mutant and constitutively activated KRAS and the expression of the death receptor TNFRSF10A. Silencing of circRAPGEF5-induced RAS/RAF/MEK/ERK signaling hyperactivation and apoptosis in CRC cells suggesting that an upregulation of circRAPEF5 may suppress the expression of TNFRSF10A and aid CRC progression by preventing apoptosis, while the direct interactions between circRAPGEF5 and elements of the RAS/RAF/MEK/ERK pathway was not identified, which nevertheless can be the basis for future research. Moreover, EIF4A3, was observed to share a similar expression pattern with circRAPEF5 and demonstrated to be a major controller of circRAPGEF5 via the promotion of circRAPGEF5 circularization and its silencing reduced circRAPGEF5 levels. Taken together, our findings reveal a mechanism of accurate RAS/RAF/MEK/ERK signaling regulation during CRC progression maintained by upregulation of circRAPGEF5 which may be a plausible target for future clinical applications that seek to induce CRC cell apoptosis via the RAS/RAF/MEK/ERK signaling pathway.

Predictive Value of Lymphocyte-to-Neutrophil Ratio and Platelet-to-Neutrophil Ratio on PD-L1 Expression in Lung Cancer.

This study aimed to examine the predictive effect of the lymphocyte-to-neutrophil ratio (LNR) and the platelet-to-neutrophil ratio (PNR) on the expression of programmed death receptor ligand 1 (PD-L1) in patients diagnosed with lung cancer. The clinical records of 86 patients diagnosed with lung cancer between January 2020 and February 2022 at Fu Yang People's Hospital were retrospectively analyzed. The records included information on age, gender, smoking history, hematological indices at the time of admission, staging of the lung malignancy, histopathological subtype, comorbidities, and the expression levels of PD-L1. Patients were stratified into two distinct cohorts based on their PD-L1 expression levels: Those with an expression level greater than or equal to 1% were classified into the PD-L1 positive expression group, while the remainder were categorized as the PD-L1 negative expression group. Univariate analysis and multivariate logistic regression analysis were used to identify the influencing factors of PD-L1, and the diagnostic efficacy was calculated using the receiver operating characteristic (ROC) curve. Upon analysis, the PD-L1 positive expression group manifested notably lower values as compared to their counterparts in the PD-L1 negative expression group (LNR: 0.262 ± 0.105 vs. 0.390 ± 0.201; PNR: 41.03 [29.64, 50.11] vs. 49.50 [37.38, 73.83]), and these differences were statistically significant. There was a notable disparity in PD-L1 expression based on gender, with males exhibiting a statistically significant higher positivity rate compared to females. Furthermore, patients in Stages I-III of the disease demonstrated a markedly elevated PD-L1 positivity rate compared to those in Stage IV (p < 0.05). Incorporating univariates with statistical differences into multivariate logistic regression analysis suggests that stage and LNR are independent risk factors for PD-L1 negative expression. ROC curve analyses revealed that the area under the ROC curve (AUC) for LNR as an indicator for PD-L1 positive expression stood at 0.706, while the AUC for PNR was calculated at 0.687. PD-L1 expression is correlated with gender and lung cancer staging, and LNR and PNR have a predictive value for PD-L1 expression.

Enhanced anticancer efficacy of TRAIL-conjugated and odanacatib-loaded PLGA nanoparticles in TRAIL resistant cancer

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) demonstrates unique characteristics in anticancer therapies as it selectively induces apoptosis in cancer cells. However, most cancer cells are TRAIL-resistant. Odanacatib (ODN), a cathepsin K inhibitor, is considered a novel sensitizer for cancer treatment. Combination therapy between TRAIL and sensitizers is considered a potent platform that improves TRAIL-based anticancer therapies beyond TRAIL monotherapy. Herein, we developed ODN loaded poly(lactic-co-glycolic) nanoparticles conjugated to GST-TRAIL (TRAIL-ODN-PLGA-NPs) to target and treat TRAIL-resistant cancer.TRAIL-ODN-PLGA-NPs demonstrated a significant increase in cellular uptake via death receptors (DR5 and DR4) on surface of cancer cells. TRAIL-ODN-PLGA-NPs exposure destroyed more TRAIL-resistant cells compared to a single treatment with free drugs. The released ODN decreased the Raptor protein, thereby increasing damage to mitochondria by elevating reactive oxygen species (ROS) generation. Additionally, Bim protein stabilization improved TRAIL-resistant cell sensitization to TRAIL-induced apoptosis. The in vivo biodistribution study revealed that TRAIL-ODN-PLGA-NPs demonstrated high location and retention in tumor sites via the intravenous route. Furthermore, TRAIL-ODN-PLGA-NPs significantly inhibited xenograft tumor models of TRAIL-resistant Caki-1 and TRAIL-sensitive MDA-MB-231 cells.The inhibition was associated with apoptosis activation, Raptor protein stabilizing Bim protein downregulation, Bax accumulation, and mitochondrial ROS generation elevation. Additionally, TRAIL-ODN-PLGA-NPs affected the tumor microenvironment by increasing tumor necrosis factor-α and reducing interleukin-6.In conclusion, we evealed that our formulation demonstrated synergistic effects against TRAIL compared with the combination of free drug in vitro and in vivo models. Therefore, TRAIL-ODN-PLGA-NPs may be a novel candidate for TRAIL-induced apoptosis in cancer treatment.

Strong activation of p53 by actinomycin D and nutlin-3a overcomes the resistance of cancer cells to the pro-apoptotic activity of the FAS ligand

The FAS ligand (FASLG) is expressed on lymphocytes, which employ it to activate death receptors on target cells. Cancer cells are generally resistant to apoptosis triggered by FASLG. In this work, we found a way to circumvent this resistance by treatment with actinomycin D (ActD) and nutlin-3a (Nut3a). We selected this drug combination based on our transcriptomic data showing strong activation of proapoptotic genes, including those for receptor-mediated apoptosis, in cells exposed to actinomycin D and nutlin-3a. To test our hypothesis, we pre-exposed cancer cell lines to this drug combination for 45 h and then treated them with recombinant FASLG. This almost instantaneously killed most cells. Actinomycin D and nutlin-3a strongly cooperated in the sensitization because the effect of the drugs acting solo was not as spectacular as the drug combination, which together with FASLG killed more than 99% of cells. Based on the caspase activation pattern (caspase-8, caspase-9, caspase-10), we conclude that both extrinsic and intrinsic pro-apoptotic pathways were engaged. In engineered p53-deficient cells, this pro-apoptotic effect was completely abrogated. Therefore, the combination of ActD + Nut3a activates p53 in an extraordinary way, which overcomes the resistance of cancer cells to apoptosis triggered by FASLG. Interestingly, other combinations of drugs, e.g., etoposide + nutlin-3a, actinomycin D + RG7112, and actinomycin D + idasanutlin had a similar effect. Moreover, normal human fibroblasts are less sensitive to death induced by ActD + Nut3a + FASLG. Our findings create the opportunity to revive the abandoned attempts of cancer immunotherapy employing the recombinant FAS ligand.Graphical

Naringin Induces ROS-Stimulated G1 Cell-Cycle Arrest and Apoptosis in Nasopharyngeal Carcinoma Cells.

Naringin, a bioflavonoid compound from grapefruit or citrus, exerts anticancer activities on cervical, thyroid, colon, brain, liver, lung, thyroid, and breast cancers. The present investigation addressed exploring the anticancer effects of naringin on nasopharyngeal carcinoma (NPC) cells. Naringin exhibits a cytotoxic effect on NPC-TW 039 and NPC-TW 076 cells with IC50 372/328 and 394/307 μM for 24 or 48 h, respectively, while causing little toxicity toward normal gingival epithelial (SG) cells (>500/500 μM). We established that naringin triggered G1 arrest is achieved by suppressing cyclin D1, cyclin A, and CDK2, and upregulating p21 protein in NPC cells. Exposure of NPC cells to naringin caused a series of events leading to apoptosis including morphology change (cell shrinkage and membrane blebbing) and chromatin condensation. Annexin V and PI staining indicated that naringin treatment promotes necrosis and late apoptosis in NPC cells. DiOC6 staining showed a decline in the mitochondrial membrane potential by naringin treatment, which was followed with cytochrome c release, Apaf-1/caspase-9/-3 activation, PARP cleavage, and EndoG expression in NPC cells. Naringin upregulated proapoptotic Bax and decreased antiapoptotic Bcl-xL expression, and dysregulated Bax/Bcl-xL ratio in NPC cells. Notably, naringin enhanced death receptor-related t-Bid expression. Furthermore, an increased Ca2+ release by naringin treatment which instigated endoplasmic reticulum stress-associated apoptosis through increased IRE1, ATF-6, GRP78, GADD153, and caspase-12 expression in NPC cells. In addition, naringin triggers ROS production, and inhibition of naringin-induced ROS generation by antioxidant N-acetylcysteine resulted in the prevention of G1 arrest and apoptosis in NPC cells. Naringin-induced ROS-mediated G1 arrest and mitochondrial-, death receptor-, and endoplasmic reticulum stress-mediated apoptosis may be a promising strategy for treating NPC.

FSH induces apoptosis in follicular granulosa cells of Tianzhu white yak and regulates the expression of Fas/FasL mRNA.

The Tianzhu white yak, a globally rare species, holds immense value as a source for yak materials. While the Fas/FasL pathway is pivotal in granulosa cells apoptosis, its precise molecular workings remain enigmatic. This study endeavours to decipher the role of follicle-stimulating hormone (FSH) in suppressing ovarian granulosa cells (GC) apoptosis in the Tianzhu white yak. Utilizing advanced cell culture techniques, we employed the MTT method, flow cytometry, fluorescence labelling and RT-PCR to investigate the apoptotic effects of FSH on yak GCs. Our results reveal that FSH's inhibitory effect on GC apoptosis follows a normal distribution pattern, peaking at an FSH concentration of 100 ng/mL with an apoptosis inhibition rate of 89.31%. When serum was withdrawn, an FSH concentration of 2 × 106 ng/mL reduced apoptosis by 72.84%. Annexin V-FITC staining revealed membrane invaginations, bubble and protrusion formation on the cell surface, and alterations in membrane structure and cell morphology. Flow cytometry analysis further demonstrated that FSH administration prior to early granulosa cell apoptosis had a more profound effect than during gradual apoptosis, both showing a suppressive effect on early follicular granulosa cell apoptosis. A transcription-level analysis conducted 3 h prior to serum withdrawal, with the addition of 100 ng/mL FSH, revealed intricate regulations in the expression of Fas/FasL. Notably, we observed a gradual increase in FasL expression over time, yet the presence of FSH effectively down-regulated FasL expression to baseline levels, without notable changes in Fas expression. Immunocytochemical analysis further confirmed the presence of both Fas and FasL on the cell membrane, nucleus and cytoplasm, with varying intensities depending on the duration of FSH treatment. Our findings suggest that FSH may suppress the apoptotic pathway in follicular primarily by down-regulating FasL expression, indicating that Fas-regulated mitochondrial pathways play a more prominent role compared to death receptor pathways. This study offers a fresh perspective on the mechanism underlying follicular atresia in Tianzhu white yaks and lays a solid theoretical foundation for the expansion of this endangered species' population.

TRAIL-induced cytokine production via NFKB2 pathway promotes neutrophil chemotaxis and immune suppression in triple negative breast cancers.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potential cancer therapeutic that induces apoptosis in cancer cells while sparing the non-malignant cells in preclinical models. However, its efficacy in clinical trials has been limited, suggesting unknown modulatory mechanisms responsible for the lack of TRAIL activity in patients. Here, we hypothesized that TRAIL treatment elicits transcriptional changes in triple negative breast cancer (TNBC) cells that alter the immune milieu. To test this, we performed an RNAseq analysis of MDA-MB-231 cells treated with TRAIL, followed by validation in additional TNBC cell lines. TRAIL significantly induces expression of multiple cytokines such as CXCLs 1, 2, 3, 8,11 and IL-6, which are known to modify neutrophil function. Mechanistically, the induction of these cytokines was predominantly mediated by death receptor 5, caspase 8 (but not caspase 8 enzymatic activity), and the non-canonical NFKB2 pathway. The cytokines produced by the TRAIL-treated TNBC cells enhanced chemotaxis of healthy human donor isolated neutrophils. In vivo , TRAIL treated TNBC murine xenograft tumors showed activation of the NFKB2 pathway, elevated production of CXCLs and IL-6, and increased neutrophil recruitment into the tumors. Moreover, donor isolated neutrophils preincubated in supernatants from TRAIL-treated TNBC cells exhibited impaired cytotoxic effect against TNBC cells. Transcriptomic analysis of neutrophils incubated with either TRAIL alone or supernatant of TRAIL-treated TNBC cells revealed increased expression of inflammatory cytokines, immune modulatory genes, immune checkpoint genes, and genes implicated in delayed neutrophil apoptosis. Functional studies with these neutrophils confirmed their suppressive effect on T cell proliferation and an increase in Treg suppressive phenotype. Collectively, our study demonstrates a novel role of TRAIL-induced NFKB2-dependent cytokine production that promotes neutrophil chemotaxis and immune suppression.

Clinical characteristics and prognosis of liver injury induced by immune checkpoint inhibitors in patients with malignancies: A real-world retrospective study.

Programmed cell death receptor (ligand)-1 inhibitors (PD-(L)1), as the preferred immunotherapy, have been widely used in the Chinese mainland and drug-induced liver injury (DILI) has been reported. The study aimed to investigate the clinical features or risk factors for immunotherapy-related DILI. Patients who received PD-(L)1 inhibitors from January 2020 to July 2021 were retrospectively reviewed. The likelihood of DILI was adjudicated by the Roussel-Uclaf causality assessment. A total of 1175 patients were included in the study and 89 patients (7.6%) developed DILI, of which 12 (13.5%) progressed to acute liver failure (ALF) and three (3.4%) died. Among the DILI population, 56 (62.9%) had a cholestatic pattern and exhibited a prolonged treatment course and duration for resolution compared to the hepatocellular and mixed patterns. Hepatocellular carcinoma (HCC), hepatitis B virus (HBV) and abnormal baseline of alkaline phosphatase (ALP) had increased risks of DILI by 2.1-fold (95% confidence interval [CI], 1.231-3.621), 1.9-fold [95% CI, 1.123-3.325] and 2.1-fold [95% CI, 1.317-3.508], respectively. The model for end-stage liver disease (MELD) score had a c-statistic of 0.894 (95% CI, 0.778-1.000) with a sensitivity of 67% and a specificity of 95% for poor outcomes. COX analysis showed that the MELD ≥ 18 was predictive of immunotherapy-related ALF or death. PD-(L)1 inhibitor-related liver injury manifests primarily as a cholestatic pattern, on which corticosteroid treatment has minimal effect compared to hepatocellular and mixed patterns. MELD score ≥ 18 at the time of liver injury performed best in the prediction of ALF or death in immune checkpoint inhibitor (ICI)-related DILI.

Prospects of compounds of herbal plants as anticancer agents: a comprehensive review from molecular pathways.

Cancer refers to the proliferation and multiplication of aberrant cells inside the human body, characterized by their capacity to proliferate and infiltrate various anatomical regions. Numerous biochemical pathways and signaling molecules have an impact on the cancer auto biogenesis process. The regulation of crucial cellular processes necessary for cell survival and proliferation, which are triggered by phytochemicals, is significantly influenced by signaling pathways. These pathways or components are regulated by phytochemicals. Medicinal plants are a significant reservoir of diverse anticancer medications employed in chemotherapy. The anticancer effects of phytochemicals are mediated by several methods, including induction of apoptosis, cessation of the cell cycle, inhibition of kinases, and prevention of carcinogenic substances. This paper analyzes the phytochemistry of seven prominent plant constituents, namely, alkaloids, tannins, flavonoids, phenols, steroids, terpenoids, and saponins, focusing on the involvement of the MAPK/ERK pathway, TNF signaling, death receptors, p53, p38, and actin dynamics. Hence, this review has examined a range of phytochemicals, encompassing their structural characteristics and potential anticancer mechanisms. It has underscored the significance of plant-derived bioactive compounds in the prevention of cancer, utilizing diverse molecular pathways. In addition, this endeavor also seeks to incentivize scientists to carry out clinical trials on anticancer medications derived from plants.

Advances in immunotherapy of M2 macrophages and gastrointestinal stromal tumor.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal-derived tumors of the GI tract. They can occur throughout the GI tract, and the survival time of some patients can be improved by first-line targeted therapy with imatinib. However, there are some limitations with imatinib treatment. Immunotherapy for GIST has attracted much attention in recent years, and as one of the most abundant cells in the GIST microenvironment, M2 macrophages play an important role in disease progression. They have unique anti-inflammatory and pro-tumorigenic effects and are one target for immunotherapy. This review summarizes the connection between different factors and the programmed death receptor-1/programmed death ligand-1 pathway and M2 macrophages to reactivate or enhance anti-tumor immunity and improve imatinib efficacy, and to provide new ideas for GIST immunotherapy.

Necroptosis plays a role in TL1A-induced airway inflammation and barrier damage in asthma

BackgroundAirway epithelial cell (AEC) necroptosis contributes to airway allergic inflammation and asthma exacerbation. Targeting the tumor necrosis factor-like ligand 1 A (TL1A)/death receptor 3 (DR3) axis has a therapeutic effect on asthmatic airway inflammation. The role of TL1A in mediating necroptosis of AECs challenged with ovalbumin (OVA) and its contribution to airway inflammation remains unclear.MethodsWe evaluated the expression of the receptor-interacting serine/threonine-protein kinase 3(RIPK3) and the mixed lineage kinase domain-like protein (MLKL) in human serum and lung, and histologically verified the level of MLKL phosphorylation in lung tissue from asthmatics and OVA-induced mice. Next, using MLKL knockout mice and the RIPK3 inhibitor GSK872, we investigated the effects of TL1A on airway inflammation and airway barrier function through the activation of necroptosis in experimental asthma.ResultsHigh expression of necroptosis marker proteins was observed in the serum of asthmatics, and necroptosis was activated in the airway epithelium of both asthmatics and OVA-induced mice. Blocking necroptosis through MLKL knockout or RIPK3 inhibition effectively attenuated parabronchial inflammation, mucus hypersecretion, and airway collagen fiber accumulation, while also suppressing type 2 inflammatory factors secretion. In addition, TL1A/ DR3 was shown to act as a death trigger for necroptosis in the absence of caspases by silencing or overexpressing TL1A in HBE cells. Furthermore, the recombinant TL1A protein was found to induce necroptosis in vivo, and knockout of MLKL partially reversed the pathological changes induced by TL1A. The necroptosis induced by TL1A disrupted the airway barrier function by decreasing the expression of tight junction proteins zonula occludens-1 (ZO-1) and occludin, possibly through the activation of the NF-κB signaling pathway.ConclusionsTL1A-induced airway epithelial necroptosis plays a significant role in promoting airway inflammation and barrier dysfunction in asthma. Inhibition of the TL1A-induced necroptosis pathway could be a promising therapeutic strategy.

Analytical quality by design (AQbD) based optimization of RP-UPLC method for determination of nivolumab and relatlimab in bulk and pharmaceutical dosage forms

BackgroundThe Analytical Quality by Design (AQbD) methodology extends the application of Quality by Design (QbD) principles to the management of the analytical procedure life cycle, encompassing method creation, optimization, validation, and continuous improvement. AQbD assists in creating analytical procedures that are robust, reliable, precise, and cost-efficient. Opdualag™ is a combination of Nivolumab and Relatlimab, which are antibodies that block programmed death receptor-1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) receptors, used to treat advanced melanoma. This work aims to develop and validate a reversed-phase ultra-performance liquid chromatography (RP-UPLC) method using AQbD principles to determine NLB and RTB in pharmaceutical products.ResultsA central composite design (CCD) comprising three factors arranged in five distinct levels was implemented via Design-expert® software to optimize the chromatographic conditions. A mathematical model was constructed and the effects of three independent factors namely flow rate (X1), percentage of methanol in the mobile phase (X2), and temperature (X3) on responses including retention time (Y1–2), resolution factor (Y3), theoretical plates (Y4–5), and tailing factor (Y6–7) were investigated. The software determined the optimal chromatographic conditions for the separation of NLB and RTB, which were as follows: 32.80% methanol in the mobile phase, 0.272 mL/min flow rate, 29.42 °C column temperature, and 260 nm UV detection. The retention time for NLB and RTB were 1.46 and 1.88 min, respectively. The method exhibited linearity across the concentration ranges of 4–24 µg/mL for RTB and 12–72 µg/mL for NLB. The limits of detection (LOD) and limit of quantification (LOQ) for NLB and RTB, respectively, were 0.89 µg/mL, 2.69 µg/mL and 0.15 µg/mL and 0.46 µg/mL. The percentage relative standard deviation (%RSD) of intraday and interday precision for NLB and RTB was below 2. The recovery percentages for NLB and RTB were determined to be 99.57–100.43% and 99.59–100.61%, respectively. Both drugs were found to be susceptible to oxidative and photolytic degradation in forced degradation studies.ConclusionsEmploying the AQbD-based methodology, a straightforward, fast, accurate, precise, specific, and stability-indicating RP-UPLC method has been established for the quantitative analysis of NLB and its RTB in pharmaceutical formulations.

Molluscan pleiotropic FADD involved in innate immune signaling and induces apoptosis

Fas-associated protein with death domain (FADD) was initially identified as a crucial adaptor protein in the apoptotic pathway mediated by death receptor (DR). Subsequently, many studies have confirmed that FADD plays a vital role in innate immunity and inflammatory responses in animals. However, the function of this pleiotropic molecule in mollusk species has not been well explored. In this study, we successfully verified the gene sequence of FADD in the Zhikong scallop (Chlamys farreri) and designated it as CfFADD. The CfFADD protein contains a conserved death effector and death domains. Phylogenetic analysis showed that CfFADD is a novel addition to the molluscan FADD family with a close evolutionary relationship with molluscan FADD subfamily proteins. CfFADD mRNA expression in various scallop tissues was significantly induced by challenge with pathogen-associated molecular patterns (lipopolysaccharide, peptidoglycan, and poly(I:C)), suggesting its role in innate immunity in scallops. Co-immunoprecipitation showed that CfFADD interacted with the scallop DR (tumor necrosis factor receptor) and a signaling molecule involved in the Toll-like receptor pathway (interleukin-1 receptor-associated kinase), confirming that CfFADD may be involved in DR-mediated apoptosis and innate immune signaling pathways. Further studies showed that CfFADD interacted with CfCaspase-8 and activated caspase-3. HEK293T cells exhibited distinct apoptotic features after transfection with a CfFADD-expression plasmid, suggesting a functional DR-FADD-caspase apoptotic pathway in scallops. Overexpression of CfFADD led to a significant dose-dependent activation of interferon β and nuclear factor-κB reporter genes, demonstrating the key role of CfFADD in innate immunity. In summary, our research has confirmed the critical roles of CfFADD in innate immunity and apoptosis and provides valuable information for developing comparative immunology theories.

TMB Signature-Related RCAN2 Promotes Apoptosis by Upregulating EHF/DR5 Pathway in Hepatocellular Carcinoma.

The tumour mutation burden (TMB) is a valuable indicator of the accumulation of somatic mutations, and is thought to be associated with the biological behaviour and prognosis of tumours. However, the related genetic mechanism for these association is still unclear. The aim of the present study was to identify the key gene(s) associated with TMB in hepatocellular carcinoma (HCC) and to investigate its biological functions, downstream transcription factors, and mechanism of action. Patients in The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) database were classified according to TMB signature-related genes. Key genes related to the TMB signature and tumour prognosis were identified. Immunohistochemistry and Quantitative Real-Time Polymerase Chain Reaction (qPCR) were then used to assess gene expression in clinical HCC tissues and HCC cells. Cells with altered gene expression were evaluated for the effect on cell proliferation and apoptosis, both in vitro and in vivo. Three independent databases and cell sequencing data were used to identify the mechanisms involved and the downstream transcription factors. The mechanism was also studied by altering the expression of downstream transcription factors in vitro. The integrated cluster (IC) 2 group, characterized by 99 TMB signature-related genes, showed a significant different TMB score compared to the IC1 group (p < 0.001), as well as more favourable tumour prognosis (p = 0.031). We identified five key prognostic genes that were differentially expressed between IC2 and IC1 and were associated with overall survival. The expression of one of these key prognostic genes, RCAN2, was negatively correlated with TMB in 18 out of 33 tumour types examined. A high level of RCAN2 was correlated with better overall survival in HCC (p = 0.0009). Overexpression of RCAN2 enhanced apoptosis in vitro and in vivo, whereas knockdown of RCAN2 attenuated apoptosis. The mechanism by which RCAN2 promotes apoptosis may involve upregulation of the expression of ETS homologous factor (EHF) and of death receptor 5 (DR5). Downregulation of RCAN2 expression was found to correlate with elevated TMB in multiple cancer types. RCAN2 was also found to be a biomarker of HCC prognosis, and to promote the apoptosis of HCC cells through the EHF/DR5 pathway. These findings provide a new perspective on systemic treatment for advanced HCC with a high TMB.

A DNA robotic switch with regulated autonomous display of cytotoxic ligand nanopatterns

The clustering of death receptors (DRs) at the membrane leads to apoptosis. With the goal of treating tumours, multivalent molecular tools that initiate this mechanism have been developed. However, DRs are also ubiquitously expressed in healthy tissue. Here we present a stimuli-responsive robotic switch nanodevice that can autonomously and selectively turn on the display of cytotoxic ligand patterns in tumour microenvironments. We demonstrate a switchable DNA origami that normally hides six ligands but displays them as a hexagonal pattern 10 nm in diameter once under higher acidity. This can effectively cluster DRs and trigger apoptosis of human breast cancer cells at pH 6.5 while remaining inert at pH 7.4. When administered to mice bearing human breast cancer xenografts, this nanodevice decreased tumour growth by up to 70%. The data demonstrate the feasibility and opportunities for developing ligand pattern switches as a path for targeted treatment.

Circulating T cell status and molecular imaging may predict clinical benefit of neoadjuvant PD-1 blockade in oral cancer

BackgroundAddition of neoadjuvant immune checkpoint inhibition to standard-of-care interventions for locally advanced oral cancer could improve clinical outcome.MethodsIn this study, 16 evaluable patients with stage III/IV oral cancer were treated...

STAMBP is Required for Long-Term Maintenance of Neural Progenitor Cells Derived from hESCs.

Mutations in STAMBP have been well-established to cause congenital human microcephaly-capillary malformation (MIC-CAP) syndrome, a rare genetic disorder characterized by global developmental delay, severe microcephaly, capillary malformations, etc. Previous biochemical investigations and loss-of-function studies in mice have provided insights into the mechanism of STAMBP, however, it remains controversial how STAMBP deficiency leads to malformation of those affected tissues in patients. In this study, we investigated the function and underlying mechanism of STAMBP during neural differentiation of human embryonic stem cells (hESCs). We found that STAMBP is dispensable for the pluripotency maintenance or neural differentiation of hESCs. However, neural progenitor cells (NPCs) derived from STAMBP-deficient hESCs fail to be long-term maintained/expanded in vitro. We identified the anti-apoptotic protein CFLAR is down-regulated in those affected NPCs and ectopic expression of CFLAR rescues NPC defects induced by STAMBP-deficiency. Our study not only provides novel insight into the mechanism of neural defects in STAMBP mutant patients, it also indicates that the death receptor mediated apoptosis is an obstacle for long-term maintenance/expansion of NPCs in vitro thus counteracting this cell death pathway could be beneficial to the generation of NPCs in vitro.

Discovery of Loureirin analogues with colorectal cancer suppressive activity via regulating cell cycle and Fas death receptor

Chalcones and dihydrochalcones (DHCs) are important bioactive natural products (BNPs) isolated from traditional Chinese medicine. In this study, 13 chalcones were designed with the inspiration of Loureirin, a DHC extracted from Resina Draconis, and synthesized by classical Claisen-Schmidt reactions. Afterwards the reduction reactions were carried out to obtain the corresponding DHCs. Cytotoxicity assay indicated chalcones and DHCs possessed selective cytotoxicity against colorectal cancer (CRC) cells. The preliminary structure-activity relationships (SAR) of these compounds suggested the α, β-unsaturated ketone of the chalcones were crucial for the anticancer activity. Interestingly, compounds 3d and 4c exhibited selective anticancer activity against CRC cell line HCT116 with IC50s of 8.4 and 17.9 μM but not normal cell. Moreover, 4c could also inhibit the migration and invasion of CRC cells. Mechanism investigations showed 4c could induce cell cycle G2/M arrest by regulating cell cycle-associated proteins and could also up-regulate Fas cell surface death receptor. The virtual docking further pointed out that compounds 3d and 4c could nicely bind to the Fas/FADD death domain complex (ID: 3EZQ). Furthermore, silencing of Fas significantly enhanced the proliferation of CRC cells and attenuated the cytotoxicity induced by 4c. These results suggested 4c exerted its anticancer activity possibly regulating cell cycle and Fas death receptor. In summary, this study investigated the anticancer activity and mechanism of Loureirin analogues in CRC, suggesting these compounds may warrant further investigation as promising anticancer drug candidates for the treatment of CRC.