Combinatorial Therapeutic Strategies Research Articles

Synergistic Anti-Tumor Effects of Newcastle Disease Virus and Doxorubicin: Evidence from A Murine Breast Cancer Model

BackgroundDespite the recent advances in the diagnosis and treatment of breast cancer, triple-negative breast cancer (TNBC) remains a clinical challenge due to its aggressive nature and resistance to conventional therapies. Virotherapy has emerged as a promising cancer treatment strategy, leveraging the ability of viruses to specifically target and replicate in cancerous cells. This study evaluated the oncolytic potential of a combined therapeutic strategy, utilizing Newcastle disease virus (NDV) and Doxorubicin hydrochloride (Dox) both in vitro and in vivo. MethodsThe in vitro experiments involved exposing human and mouse TNBC cell lines (MDA-MB-231 and 4T1, respectively) to NDV and Dox, individually or in combination. Cell viability assays and flow cytometry analyses were conducted to assess the synergistic effects of NDV and Dox on regulating breast cancer cell behavior in vitro. Furthermore, the immune-stimulating potential of NDV was investigated by examining its effects on dendritic cell (DC) maturation using flow cytometry and T cell proliferation. The in vitro anti-tumor effects of NDV were examined in both parental and tamoxifen-resistant cancer cells to assess its efficacy against chemoresistance. Animal models of breast cancer were treated with NDV in combination with Dox. The body weight changes, tumor volume, and survival rates of the mice were monitored throughout the study. Histopathological analyses were conducted to evaluate the potential toxic effects of the treatments. ResultsBased on the MTT results, NDV at optimal concentrations synergized the effect of Dox to reduce the viability of both MDA-MB231 and 4T1 cell lines (Isobologram combination index of less than 1). Additionally, individual treatment with NDV was able to significantly reduce the viability of patient-derived breast cancer cells, compared to the untreated control (P < 0.05) without affecting the cells of normal adjacent tissue. Furthermore, a combination of NDV and Dox significantly enhanced the percentage of early and late apoptotic cells in MDA-MB-231 (P < 0.0001) and late apoptotic cells in 4T1 (P < 0.0001), in comparison with individual treatment with these agents. Flow cytometry results showed that, compared to wild type MDA-MB-231 cells, NDV-infected MDA-MB-231 cells were better inducers of T cell proliferation and DC maturation as evidenced by increased proliferation index (P < 0.05) and elevated expression of CD1a, CD83, and CD86 (P < 0.0001), respectively. Moreover, co-treatment of both wild-type and (tamoxifen) TAM-resistant MCF-7/TAMR-1 cells with TAM and NDV significantly reduce the viability of the cancer cells (P < 0.0001). In tumor-bearing mice locally engrafted with 4T1 cells, combined treatment of NDV and Dox exhibited a marked reduction in median tumor volume compared to the control group, validating our in vitro findings on their synergistic anti-tumor effects. These findings suggest that combining NDV with Dox can effectively inhibit tumor progression and has the potential to reduce the dose, and consequently the toxic side-effects, of Dox in breast cancer therapy.

Supramolecular PEG-DNA-Ferrocene Nanogels for Synergistically Amplified Chemodynamic Therapy via Cascade Reactions.

Chemodynamic therapy (CDT) has been limited by the tumor microenvironment, such as the low concentration of hydrogen peroxide (H2O2). The combination of therapeutic strategies that increase H2O2 with CDT can synergistically enhance the therapeutic effect. Herein, a novel supramolecular PEG-DNA-ferrocene nanogel that can codeliver glucose oxidase (GOx) and the hypoxia-activable prodrug tirapazamine (TPZ) was developed to synergistically amplify CDT via cascade reactions. The DNA nanogel was size-controllable and DNase I-responsive and exhibited good biocompatibility. Induced by oxygen consumption and H2O2 generation in the catalytic reaction of GOx, the drugs TPZ and ferrocene in the nanogel underwent the hypoxia-based reaction and the Fenton reaction, respectively. The vitro model tests, intracellular ROS test, MTT experiments, and DNA damage assay demonstrated that the H2O2-based cascade Fenton reaction and the hypoxia-based cascade reaction obviously increased ·OH generation and promoted the apoptosis of cancer cells. This cascade supramolecular nanoplatform provided a promising therapeutic strategy to synergistically amplify CDT.

Co-Delivery of VEGF siRNA and THPP via Metal-Organic Framework Reverses Cisplatin-Resistant Non-Small Cell Lung Cancer and Inhibits Metastasis through a MUC4 Regulating Mechanism.

Cisplatin resistance significantly impacts the antitumor efficacy of cisplatin chemotherapy and contributes to poor prognosis, including metastasis. In this study, we present the utilization of metal-organic framework (MOF) nanoparticles as the therapeutic component and drug loading scaffold for implementing a ternary combination therapeutic strategy to combat cisplatin-resistant lung cancer and metastasis. Specifically, by engineering MOFs (Cis@MOF-siVEGF) through the self-assembly of THPP as photosensitizer for photodynamic therapy (PDT), along with the incorporation of cisplatin (DDP) and VEGF siRNA (siVEGF), we propose the leverage of photodynamic-induced oxidative damage and gene silencing of the angiogenic factor to reverse cisplatin resistance and sensitize therapeutic potency. Our findings demonstrated that the chemo/photodynamic/antiangiogenic triple combination therapy via Cis@MOF-siVEGF under irradiation effectively inhibits cisplatin-resistant tumor growth and induces abscopal effects. Importantly, molecular mechanistic exploration suggested that MUC4 exerted regulatory effects on governing cancer metastasis, thus representing a potential immunotherapeutic target for cancer intervention. Overall, our study creates a MOFs-based multicomponent delivery platform for complementary therapeutic modules with synergistically enhanced antitumor efficacy and sheds light on potential regulatory mechanisms on cisplatin-resistance cancers.

Single-cell transcriptome analysis reveals evolving tumour microenvironment induced by immunochemotherapy in nasopharyngeal carcinoma.

Combinatory therapeutic strategy containing immunochemotherapy as part of induction therapy components is one of the current trends in the treatment of high-risk metastatic locally advanced nasopharyngeal carcinoma (NPC). However, the mechanism underlying the heterogeneity of response at the single-cell level has not been underexplored. 18 bulks and 11 single-cell RNA sequencing from paired before-treatment and on-treatment samples in patients with treatment-naive high-risk metastatic locally advanced NPCs were obtained. Following quality control, a total of 87191 cells were included in the subsequence bioinformatics analysis. Immunochemotherapy was associated with on-treatment tumour microenvironment (TME) remodelling, including upregulation of anti-TMEs signatures, downregulation of pro-TMEs signatures, reversing CD8+ T exhaustion, and repolarizing proinflammatory TAMs. For the patients achieving a complete response, the cytotoxic activity of CD8+ T cells was stimulated and more interferon-gamma was provided, which would be the key for TAMs proinflammatory repolarization and eventually promote the CD8+ T cells maturation in turn. Among patients who did not reach complete response, differentiation and hypoxia signatures for endothelial cells were elevated after therapy. These patients exhibited higher levels of immune checkpoint genes in malignant cells at the baseline (before treatment), and decreased tumour antigen presentation activity, which may underlie the resistance mechanism to therapy. This study pictures a map of TME modulation following immunochemotherapy-based combination induction therapy and provides potential future approaches. Immunochemotherapy remodeled T cell phenotypes. For the patients achieving complete response, more interferon gamma was provided by CD8+ T cells after therapy, which would be the key for TAMs pro-inflammatory repolarization and eventually promote the CD8+ T cells maturation in turns. Among patients who did not reach complete response, malignant cells exhibited higher level of immune checkpoint genes before therapy, and decreased tumor antigen presentation activity, which may underlie the resistance mechanism to therapy.

BAP1 regulates HSF1 activity and cancer immunity in pancreatic cancer

BackgroundThe vast majority of pancreatic cancers have been shown to be insensitive to single-agent immunotherapy. Exploring the mechanisms of immune resistance and implementing combination therapeutic strategies are crucial for PDAC patients to derive benefits from immunotherapy. Deletion of BAP1 occurs in approximately 27% of PDAC patients and is significantly correlated with poor prognosis, but the mechanism how BAP1-deletion compromises survival of patients with PDAC remain a puzzle.MethodsBap1 knock-out KPC (KrasG12D/+; LSLTrp53R172H/+; Pdx-1-Cre) mice and control KPC mice, syngeneic xenograft models were applied to analysis the correlation between BAP1 and immune therapy response in PDAC. Immunoprecipitation, RT-qPCR, luciferase and transcriptome analysis were combined to revealing potential mechanisms. Syngeneic xenograft models and flow cytometry were constructed to examine the efficacy of the inhibitor of SIRT1 and its synergistic effect with anti-PD-1 therapy.ResultThe deletion of BAP1 contributes to the resistance to immunotherapy in PDAC, which is attributable to BAP1’s suppression of the transcriptional activity of HSF1. Specifically, BAP1 competes with SIRT1 for binding to the K80 acetylated HSF1. The BAP1-HSF1 interaction preserves the acetylation of HSF1-K80 and promotes HSF1-HSP70 interaction, facilitating HSF1 oligomerization and detachment from the chromatin. Furthermore, we demonstrate that the targeted inhibition of SIRT1 reverses the immune insensitivity in BAP1 deficient PDAC mouse model.ConclusionOur study elucidates an unrevealed mechanism by which BAP1 regulates immune therapy response in PDAC via HSF1 inhibition, and providing promising therapeutic strategies to address immune insensitivity in BAP1-deficient PDAC.

LncRNA-Mediated TPI1 and PKM2 Promote Self-Renewal and Chemoresistance in GBM.

Temozolomide (TMZ) resistance is one of the major reasons for poor prognosis in patients with glioblastoma (GBM). Long noncoding RNAs (lncRNAs) are involved in multiple biological processes, including TMZ resistance. Linc00942 is a potential regulator of TMZ sensitivity in GBM cells is shown previously. However, the underlying mechanism of TMZ resistance induced by Linc00942 is unknown. In this study, the sequence of Linc00942 by rapid amplification of cDNA ends assay in TMZ-resistant GBM cells is identified and confirmed that Linc00942 contributes to self-renewal and TMZ resistance in GBM cells. Chromatin isolation by RNA purification followed by mass spectrometry (ChIRP-MS) and followed by Western blotting (ChIRP-WB) assays shows that Linc00492 interacted with TPI1 and PKM2, subsequently promoting their phosphorylation, dimerization, and nuclear translocation. The interaction of Linc00942 with TPI1 and PKM2 leads to increased acetylation of H3K4 and activation of the STAT3/P300 axis, resulting in the marked transcriptional activation of SOX9. Moreover, the knockdown of SOX9 reversed TMZ resistance induced by Linc00492 both in vitro and in vivo. In summary, Linc00942 strongly promotes SOX9 expression by interacting with TPI1 and PKM2 is found, thereby driving self-renewal and TMZ resistance in GBM cells. These findings suggest potential combined therapeutic strategies to overcome TMZ resistance in patients with GBM.

Anti-PD-L1 blockade facilitates antitumor effects of radiofrequency ablation by improving tumor immune microenvironment in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a complex disease with advanced presentation that significantly affects survival rates. Therefore, novel therapeutic strategies are needed. In this study, we investigate the tumor microenvironment (TME) in HCC by analyzing 13 HCC samples at single cell level. We identified key cell populations, including CD8 + T cells, Tregs, M1/M2 macrophages, and CD4 + memory T cells, and explored their roles and interactions. Our research revealed an early enrichment of CD8 + T cells, which could potentially lead to their exhaustion and facilitate tumor progression. We also investigated the impact of percutaneous radiofrequency ablation (RFA) on the immune microenvironment. Using a dual tumor mouse model, we demonstrated that RFA induces necrosis, enhancing antigen presentation and altering immune responses. Our results indicate that RFA increases PD-L1 expression in residual liver tissue, suggesting potential immune escape mechanisms. Furthermore, the combination of RFA and anti-PD-L1 therapy in the mouse model resulted in significant improvements in immune modulation. This included increased CD8 + T cell efficacy and decreased Treg infiltration. This combination shows promise as an approach to counteract HCC progression by altering the immune landscape. This study highlights the critical interaction within the TME of HCC and suggests the possibility of improving patient outcomes by targeting immune evasion mechanisms through combined therapeutic strategies.

Multi-therapeutic-activity selenium nanodot toward preventing brain injury and restoring neurobehavioral functions following hemorrhagic stroke

Intracerebral hemorrhage is a lethal cerebrovascular disease, and the inevitable secondary brain injury (SBI) is responsible for serious disability and death. Perfect therapeutic goal is to minimize SBI and restore neurobehavioral functions. Recently, neuroprotection is highlighted to reduce SBI, but it still faces “Neuronal survival but impaired functions” dilemma. Herein, this work further proposes a novel combinational therapeutic strategy of neuroprotection and neurogenesis toward this goal. However, appropriate therapeutic agents are rarely reported, and their discovery and development are urgently needed. Selenium participates in various physiological/pathological processes, which is hypothesized as a potential targeting molecule. To explore this effect, this work formulates an ultra-small selenium nanodot with a seleno-amino acid derived carbon dot domain and a hydrophilic PEG layer, surprisingly finding that it increases various selenoproteins levels at perihematomal region, to not only exert multiple neuroprotective roles at acute phase but promote neurogenesis and inhibit glial scar formation at recovery phase. At a safe dose, this combinational strategy effectively prevents SBI and recovers neurobehavioral functions to a normal level. Furthermore, its molecular mechanisms are revealed to broaden application scopes in other complex diseases.Graphical abstract

MEK inhibitors lead to PDGFR pathway upregulation and sensitize tumors to RAF dimer inhibitors in NF1-deficient malignant peripheral nerve sheath tumor (MPNST).

Malignant peripheral nerve sheath tumor (MPNST) is a highly aggressive subtype of soft tissue sarcoma with a high propensity to metastasize and extremely limited treatment options. Loss of the RAS-GAP NF1 leads to sustained RAF/MEK/ERK signaling in MPNST. However, single-agent MEK inhibitors (MEKi) have failed to elicit a sustained inhibition of the MAPK signaling pathway in MPNST. We employed pharmacological, biochemical, and genetic perturbations of the receptor tyrosine kinase (RTK) and MAPK signaling pathway regulators to investigate the mechanisms of MEKi resistance and evaluated combination therapeutic strategies in various preclinical MPNST models in vitro and in vivo. Here, we report that MEKi treatment resistance in MPNST involves two adaptive pathways: direct transcriptional upregulation of the receptor tyrosine kinase (RTK) PDGFRβ, and MEKi-induced increase in RAF dimer formation and activation of downstream signaling. While the pharmacological combination of MEKi with a PDGFRβ specific inhibitor was more effective than treatment with MEKi alone, the combination of MEKi and RAF-dimer inhibitors led to a robust inhibition of the MAPK pathway signaling. This combination treatment was effective in vitro and in vivo, as demonstrated by the significant increase in drug synergism and its high effectiveness in decreasing MPNST viability. Our findings suggest that the combination of MEKi and PDGFR and/or RAF dimer inhibitors can overcome MEKi resistance and may serve as a novel targeted therapeutic strategy for NF1-deficient MPNST patients, which in turn could impact future clinical investigations for this patient population.

CEBPB dampens the cuproptosis sensitivity of colorectal cancer cells by facilitating the PI3K/AKT/mTOR signaling pathway.

Cuproptosis is a novel pathway that differs from other forms of cell death and has been confirmed to be applicable for predicting tumor prognosis and clinical treatment response. However, the mechanism underlying the resistance of colorectal cancer (CRC) to cuproptosis at the molecular level has not been elucidated. Using bioinformatics analysis, the expression of CCAAT/enhancer-binding protein beta (CEBPB) in CRC tissues and its enrichment in biological processes were detected. Quantitative reverse transcription polymerase chain reaction and western blotting (WB) were employed to test the expression of CEBPB in CRC cells. WB was utilized to assess the levels of proteins related to cuproptosis and the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. The MTT assay was used to test cell viability. Cell proliferation was assessed by a colony formation assay. Transwell assays were used to measure cell migration and invasion ability. DLAT-aggregate formation was determined by immunofluorescence. CEBPB was highly upregulated in CRC cells to enhance cell viability, proliferation, migration, and invasion. CEBPB was strongly implicated in copper ion homeostasis and the mTOR signaling pathway in CRC. In a CRC cuproptosis cell model, rescue experiments revealed that a PI3K/AKT/mTOR pathway inhibitor attenuated the promoting effect of CEBPB overexpression on the PI3K/AKT/mTOR pathway and rescued the sensitivity of CRC to cuproptosis. This work demonstrated that CEBPB can activate the PI3K/AKT/mTOR signaling pathway, thereby decreasing the sensitivity of CRC to cuproptosis. These data suggested that targeting CEBPB or the PI3K/AKT/mTOR pathway may enhance the sensitivity of CRC patients to cuproptosis, providing a combined therapeutic strategy for cuproptosis-induced therapy.

AKR1C1 interacts with STAT3 to increase intracellular glutathione and confers resistance to oxaliplatin in colorectal cancer

Oxaliplatin (OXA), a platinum-based chemotherapeutic agent, remains a mainstay in first-line treatments for advanced colorectal cancer (CRC). However, the eventual development of OXA resistance represents a significant clinical challenge. In the present study, we demonstrate that the aldo-keto reductase 1C1 (AKR1C1) is overexpressed in CRC cells upon acquisition of OXA resistance, evident in OXA-resistant CRC cell lines. We employed genetic silencing and pharmacological inhibition strategies to establish that suppression of AKR1C1 restores OXA sensitivity. Mechanistically, AKR1C1 interacts with and activates the transcription factor STAT3, which upregulates the glutamate transporter EAAT3, thereby elevating intracellular glutathione levels and conferring OXA resistance. Alantolactone, a potent natural product inhibitor of AKR1C1, effectively reverses this chemoresistance, restricting the growth of OXA-resistant CRC cells both in vitro and in vivo. Our findings uncover a critical AKR1C1-dependent mechanism behind OXA resistance and propose a promising combinatorial therapeutic strategy to overcome this resistance in CRC.

Identification of leukemia stem cell subsets with distinct transcriptional, epigenetic and functional properties

The leukemia stem cell (LSC) compartment is a complex reservoir fueling disease progression in acute myeloid leukemia (AML). The existence of heterogeneity within this compartment is well documented but prior studies have focused on genetic heterogeneity without being able to address functional heterogeneity. Understanding this heterogeneity is critical for the informed design of therapies targeting LSC, but has been hampered by LSC scarcity and the lack of reliable cell surface markers for viable LSC isolation. To overcome these challenges, we turned to the patient-derived OCI-AML22 cell model. This model includes functionally, transcriptionally and epigenetically characterized LSC broadly representative of LSC found in primary AML samples. Focusing on the pool of LSC, we used an integrated approach combining xenograft assays with single-cell analysis to identify two LSC subtypes with distinct transcriptional, epigenetic and functional properties. These LSC subtypes differed in depth of quiescence, differentiation potential, repopulation capacity, sensitivity to chemotherapy and could be isolated based on CD112 expression. A majority of AML patient samples had transcriptional signatures reflective of either LSC subtype, and some even showed coexistence within an individual sample. This work provides a framework for investigating the LSC compartment and designing combinatorial therapeutic strategies in AML.

Inhibition of MSH6 augments the antineoplastic efficacy of cisplatin in non-small cell lung cancer as autophagy modulator

The altered response to chemotherapeutic agents predominantly stems from heightened single-point mutations within coding regions and dysregulated expression levels of genes implicated in drug resistance mechanisms. The identification of biomarkers based on mutation profiles and expression levels is pivotal for elucidating the underlying mechanisms of altered drug responses and for refining combinatorial therapeutic strategies in the field of oncology. Utilizing comprehensive bioinformatic analyses, we investigated the impact of eight mismatch repair (MMR) genes on overall survival across 23 cancer types, encompassing more than 7500 tumors, by integrating their mutation profiles. Among these genes, MSH6 emerged as the most predictive biomarker, characterized by a pronounced mutation frequency and elevated expression levels, which correlated with poorer patient survival outcomes.The wet lab experiments disclosed the impact of MSH6 in mediating altered drug responses. Cytotoxic assays conducted revealed that the depletion of MSH6 in H460 non-small lung cancer cells augmented the efficacy of cisplatin, carboplatin, and gemcitabine. Pathway analyses further delineated the involvement of MSH6 as a modulator, influencing the delicate equilibrium between the pro-survival and pro-death functions of autophagy.Our study elucidates the intricate interplay between MSH6, autophagy, and cisplatin efficacy, highlighting MSH6 as a potential therapeutic target to overcome cisplatin resistance. By revealing the modulation of autophagy pathways by MSH6 inhibition, our findings offer insights into novel approaches for enhancing the efficacy of cisplatin-based cancer therapy through targeted interventions.

GJB2 Promotes HCC Progression by Activating Glycolysis Through Cytoplasmic Translocation and Generating a Suppressive Tumor Microenvironment Based on Single Cell RNA Sequencing.

Despite substantial breakthroughs in the treatment of hepatocellular carcinoma (HCC) in recent years, many patients are diagnosed in the middle or late stages, denying them the option for surgical excision. Therefore, it is of great importance to find effective therapeutic targets of HCC. In this study, it is found that Gap junction protein beta-2 (GJB2) is highly enriched in malignant cells based on single-cell RNA sequencing and higher expression of GJB2 indicates a worse prognosis. The localization of GJB2 in HCC cancer cells is changed compared with normal liver tissue. In cancer cells, GJB2 tends to be located in the cytoplasm and nucleus, while in normal tissues, GJB2 is mainly located on the cell membrane. GJB2 is related to glycolysis, promoting NF-κB pathway via inducing the ubiquitination degradation of IκBa, and activating HIF-1α/GLUT-1/PD-L1 pathway. In addition, GJB2 knockdown reshapes tumor immune microenvironment and Salvianolic acid B inhibits the activity of GJB2. In conclusion, GJB2 promotes HCC progression by activating glycolysis through cytoplasmic translocation and generating a suppressive tumor microenvironment. Salvianolic acid B inhibits the expression of GJB2 and enhances the sensitivity of anti-PD1 therapy, which may provide insights into the development of novel combination therapeutic strategies for HCC.

MiR-185–5p rewires cisplatin resistance by restoring miR-203a-3p expression via downregulation of SOX9

Chemotherapeutic drug resistance is a challenge for the effective treatment of OSCC. There are a couple of studies on the involvement of microRNAs (miRNAs) in chemoresistance of oral squamous cell carcinoma (OSCC), but the exact molecular events in many cases are not clearly understood. In this work, we intend to track down key miRNA(s) and unveil their regulatory molecular mechanisms in imparting chemoresistance in this lethal cancer. We analyzed gene and miRNA array profiles of drug-resistant OSCC cells, predicted miRNA targets, performed enrichment analysis, and validated our findings in cisplatin-sensitive and cisplatin-resistant SCC9 and H357 OSCC cells. We evaluated the anticancer and chemosensitivity roles of selected miRNA by adopting several molecular assays like qRT-PCR, MTT assay, wound healing assay, fluorescence imaging by DCFHDA, AO/EB staining, DAPI, and γ-H2AX accumulation assay. We also validated the miRNA-target binding by qRT-PCR and luciferase reporter assay. Among the enriched miRNAs, we found miR-185–5p downregulated in cisplatin-resistant OSCC cells as a signature miRNA modulating chemoresistance. The upregulation of miR-185–5p by mimic transfection restores cisplatin sensitivity by decreasing cell viability in a dose-dependent manner and increasing ROS-induced DNA damage and apoptosis. miR-185–5p overexpression increases miR-203a-3p expression through negative regulation of SOX9. siRNA-mediated silencing of the SOX9 also shows similar results. Mechanistically, miR-185–5p dependent miR-203a-3p expression decreases cisplatin efflux and cisplatin-induced DNA damage repair by regulating ABCC1, ABCB1, RRM2, and RAN. This study will pave the way for employing this miR-185–5p as a combination therapeutic strategy to combat cisplatin resistance in oral cancer.

Disrupting YAP1-mediated glutamine metabolism induces synthetic lethality alongside ODC1 inhibition in osteosarcoma.

Osteosarcoma, a highly malignant primary bone tumor primarily affecting adolescents, frequently develops resistance to initial chemotherapy, leading to metastasis and limited treatment options. Our study aims to uncover novel therapeutic targets for metastatic and recurrent osteosarcoma. In this study, we proved the potential of modulating the YAP1-regulated glutamine metabolic pathway to augment the response of OS to DFMO. We initially employed single-cell transcriptomic data to gauge the activation level of polyamine metabolism in MTAP-deleted OS patients. This was further substantiated by transcriptome sequencing data from recurrent and non-recurrent patient tissues, confirming the activation of polyamine metabolism in progressive OS. Through high-throughput drug screening, we pinpointed CIL56, a YAP1 inhibitor, as a promising candidate for a combined therapeutic strategy with DFMO. In vivo, we utilized PDX and CDX models to validate the therapeutic efficacy of this drug combination. In vitro, we conducted western blot analysis, qPCR analysis, immunofluorescence staining, and PuMA experiments to monitor alterations in molecular expression, distribution, and tumor metastasis capability. We employed CCK-8 and colony formation assays to assess the proliferative capacity of cells in the experimental group. We used flow cytometry and reactive oxygen probes to observe changes in ROS and glutamine metabolism within the cells. Finally, we applied RNA-seq in tandem with metabolomics to identify metabolic alterations in OS cells treated with a DFMO and CIL56 combination. This enabled us to intervene and validate the role of the YAP1-mediated glutamine metabolic pathway in DFMO resistance. Through single-cell RNA-seq data analysis, we pinpointed a subset of late-stage OS cells with significantly upregulated polyamine metabolism. This upregulation was further substantiated by transcriptomic profiling of recurrent and non-recurrent OS tissues. High-throughput drug screening revealed a promising combination strategy involving DFMO and CIL56. DFMO treatment curbs the phosphorylation of YAP1 protein in OS cells, promoting nuclear entry and initiating the YAP1-mediated glutamine metabolic pathway. This reduces intracellular ROS levels, countering DFMO's anticancer effect. The therapeutic efficacy of DFMO can be amplified both in vivo and in vitro by combining it with the YAP1 inhibitor CIL56 or the glutaminase inhibitor CB-839. This underscores the significant potential of targeting the YAP1-mediated glutamine metabolic pathway to enhance efficacy of DFMO. Our findings elucidate YAP1-mediated glutamine metabolism as a crucial bypass mechanism against DFMO, following the inhibition of polyamine metabolism. Our study provides valuable insights into the potential role of DFMO in an "One-two Punch" therapy of metastatic and recurrent osteosarcoma.

Mesoporous zinc-polyphenol nanozyme for attenuating renal ischemia-reperfusion injury.

Aim: To target the reactive oxygen species (ROS) accumulation and renal tubular epithelial cell (rTEC) death in renal ischemia-reperfusion injury (IRI), we constructed a nanoparticle that offers ROS scavenging and rTEC-death inhibition: mesoporous zinc-tannic acid nanozyme (ZnTA).Materials & methods: After successfully constructing ZnTA, we proceeded to examine its effect on ROS accumulation, cellular ferroptosisand apoptosis, as well as injury severity.Results: Malondialdehyde, Fe2+ amounts and 4-HNE staining demonstrated that ZnTA effectively attenuated rTEC ferroptosis. TUNEL staining confirmed that Zn2+ carried by ZnTA could effectively inhibit caspase 3 and caspase 9, mitigating apoptosis. Finally, it reduced renal IRI through the synergistic effect of ROSscavenging and cell-death inhibition.Conclusion: This study is expected to provide a paradigm for a combined therapeutic strategy for renal IRI.

Overexpression of ESYT3 improves radioimmune responses through activating cGAS-STING pathway in lung adenocarcinoma

BackgroundRadiotherapy can modulate systemic antitumor immunity, while immune status in the tumor microenvironment also influences the efficacy of radiotherapy, but relevant molecular mechanisms are poorly understood in lung adenocarcinoma (LUAD).MethodsIn this study, we innovatively proposed a radiotherapy response classification for LUAD, and discovered ESYT3 served as a tumor suppressor and radioimmune response sensitizer. ESYT3 expression was measured both in radioresistant and radiosensitive LUAD tissues and cells. The influence of ESYT3 on radiotherapy sensitivity and resistance was then investigated. Interaction between ESYT3 and STING was evaluated through multiple immunofluorescent staining and coimmunoprecipitation, and downstream molecules were further analyzed. In vivo models were constructed to assess the combination treatment efficacy of ESYT3 overexpression with radiotherapy.ResultsWe found that radioresistant subtype presented immunosuppressive state and activation of DNA damage repair pathways than radiosensitive subtype. ESYT3 expression was remarkably attenuated both in radioresistant LUAD tissues and cells. Clinically, low ESYT3 expression was linked with radioresistance. Overexpression of ESYT3 enabled to alleviate radioresistance, and sensitize LUAD cells to DNA damage induced by irradiation. Mechanically, ESYT3 directly interacted with STING, and activated cGAS-STING signaling, subsequently increasing the generation of type I IFNs as well as downstream chemokines CCL5 and CXCL10, thus improving radioimmune responses. The combination treatment of ESYT3 overexpression with radiotherapy had a synergistic anticancer effect in vitro and in vivo.ConclusionsIn summary, low ESYT3 expression confers resistance to radiotherapy in LUAD, and its overexpression can improve radioimmune responses through activating cGAS-STING-dependent pathway, thus providing an alternative combination therapeutic strategy for LUAD patients.

Nanodelivery Optimization of IDO1 Inhibitors in Tumor Immunotherapy: Challenges and Strategies.

Tryptophan (Trp) metabolism plays a vital role in cancer immunity. Indoleamine 2.3-dioxygenase 1 (IDO1), is a crucial enzyme in the metabolic pathway by which Trp is degraded to kynurenine (Kyn). IDO1-mediated Trp metabolites can inhibit tumor immunity and facilitate immune evasion by cancer cells; thus, targeting IDO1 is a potential tumor immunotherapy strategy. Recently, numerous IDO1 inhibitors have been introduced into clinical trials as immunotherapeutic agents for cancer treatment. However, drawbacks such as low oral bioavailability, slow onset of action, and high toxicity are associated with these drugs. With the continuous development of nanotechnology, medicine is gradually entering an era of precision healthcare. Nanodrugs carried by inorganic, lipid, and polymer nanoparticles (NPs) have shown great potential for tumor therapy, providing new ways to overcome tumor diversity and improve therapeutic efficacy. Compared to traditional drugs, nanomedicines offer numerous significant advantages, including a prolonged half-life, low toxicity, targeted delivery, and responsive release. Moreover, based on the physicochemical properties of these nanomaterials (eg, photothermal, ultrasonic response, and chemocatalytic properties), various combination therapeutic strategies have been developed to synergize the effects of IDO1 inhibitors and enhance their anticancer efficacy. This review is an overview of the mechanism by which the Trp-IDO1-Kyn pathway acts in tumor immune escape. The classification of IDO1 inhibitors, their clinical applications, and barriers for translational development are discussed, the use of IDO1 inhibitor-based nanodrug delivery systems as combination therapy strategies is summarized, and the issues faced in their clinical application are elucidated. We expect that this review will provide guidance for the development of IDO1 inhibitor-based nanoparticle nanomedicines that can overcome the limitations of current treatments, improve the efficacy of cancer immunotherapy, and lead to new breakthroughs in the field of cancer immunotherapy.

Novel gene therapy for drug-resistant melanoma: Synergistic combination of PTEN plasmid and BRD4 PROTAC-loaded lipid nanocarriers

Patients suffering from BRAF mutant melanoma have tumor recurrence within merely 7 months of treatment with a potent BRAF inhibitor (BRAFi) like vemurafenib (VEM). It has been proven that diverse molecular pathways driving BRAFi resistance converge to activation of c-Myc in melanoma. Therefore, we identified a novel combinatorial therapeutic strategy by targeting loss of PTEN tumor suppressor gene and upregulated BRD4 oncoprotein as Myc-dependent vulnerabilities of drug-resistant melanoma. Being promising therapeutic targets, we decided to concomitantly deliver PTEN plasmid and BRD4 targeted PROteolysis-TArgeting Chimera (ARV) to drug the “undruggable” c-Myc in BRAFi-resistant melanoma. Since PTEN plasmid and ARV are distinct in their physicochemical properties, we fabricated PTEN-plasmid loaded LNPs (PL-NANO) and ARV-825 loaded nanoliposomes (AL-NANO) to yield mean particle size of <100 nm and >99% encapsulation efficiency for each therapeutic payload. Combination of PL-NANO and AL-NANO displayed synergistic tumor growth inhibition and substantial apoptosis in in vitro 2D and 3D models. Importantly, simultaneous delivery of PL-NANO and AL-NANO achieved significant upregulation of PTEN expression levels and degradation of BRD4 protein to ultimately downregulate c-Myc levels in BRAFi-resistant melanoma cells. Altogether, lipid nanocarriers delivering this novel lethal cocktail stands as “one-of-a-kind” gene therapy to target “undruggable” c-Myc oncogene in BRAFi-resistant melanoma.