Immunotherapy For Osteosarcoma Research Articles

Insights to biology and immunotherapy of osteosarcoma

Insights to biology and immunotherapy of osteosarcoma

Proceedings of the Think Tank for Osteosarcoma Medical Advisory Board.

A "Think Tank for Osteosarcoma" medical advisory board meeting was held in Santa Monica, CA, USA on February 2-3, 2024. The goal was to develop a strategic approach to prevent recurrence of osteosarcoma. Osteosarcoma metabolism and the genomic instability of osteosarcoma, immunotherapy for osteosarcoma, CAR-T cell therapy, DeltaRex-G tumor-targeted gene therapy, repurposed drugs, alternative medicines, and personalized medicine were discussed. Only DeltaRex-G was voted on. The conclusions were the following: No intervention has been demonstrated to improve survival in a clinical trial. Additionally, the consensus (10/12 in favor) was that DeltaRex-G without immunotherapy may be administered for up to one year. Phase 2/3 randomized studies of DeltaRex-G should be performed to determine whether the incidence of recurrence could be reduced in high-risk individuals. Furthermore, a personalized approach using drugs with minimal toxicity could be attempted with the acknowledgement that there are no efficacy data to base this on. Repurposed drugs and alternative therapies should be tested in mouse models of osteosarcoma. Moreover, unmodified IL-2 primed Gamma Delta (NK) cell therapy may be used to prevent recurrence. Lastly, rapid development of CAR-T cell therapy is recommended, and an institute dedicated to the study of osteosarcoma is needed.

Immune amplifying hydrogel microspheres with STING activation improve tumor retention for photoimmunotherapy

STING agonists have shown a great promise in tumor immunotherapy by activating innate immunity. However, systemic administration can easily lead to cytokine storm, and poor retention in tumor cannot activate a highly effective immune response. Herein, our photoimmune hydrogel microspheres directly addressed the above challenges. Immunonanoparticles were first synthesized by the hydrophilic interaction among polymer PEG-PCL, photosensitizer Cypate and STING agonist MSA-2. Then, the nanoparticles mixed with GelMA and photoinitiator were used as water phase, mineral oil was the oil phase. An immune amplifying hydrogel microsphere was finally constructed by regulating the flow ratio of water and oil phases through an injection pump and a microfluidic chip, which could improve the tumor retention of STING agonist to reverse the immunosuppressive microenvironment in tumors. The photothermal and photodynamic effect generated from the photosensitizer Cypate and the sustained release of STING agonist MSA-2 promoted the release of IFN-α and IFN-β by cGAS-STING pathway, which further strengthened the photoimmune activation. In vivo data demonstrated the tumor retention of hydrogel microspheres and enhanced the infiltration of T cells in tumor. Our work demonstrated an effective therapeutic strategy for innate immunotherapy in osteosarcoma, as well as an idea for other immunosuppressive tumors.

Potential predictive value of immune-related genes FUCA1 and NCKAP1L for osteosarcoma metastasis

BackgroundOsteosarcoma is a common malignant tumor with a low survival rate after metastasis. Current treatments have not proven to effectively increase patient survival rates. Immunotherapy is a promising new treatment approach, however, immune target therapy has not shown satisfactory results. This study aims to provide new insights and evidence for the use of immunotherapy in osteosarcoma, based on a comprehensive analysis of gene expression data from databases. MethodsGene expression and GSAV analysis were conducted on samples from patients with metastatic and non-metastatic osteosarcoma in the TARGET and GEO databases to identify relevant genes. These genes were further analyzed using GO, KEGG, GSVA, correlation analysis, and immune microenvironment scoring techniques. The tissue location of gene expression was confirmed through single-cell analysis. Validation of gene expression patterns was performed using polymerase chain reaction, western blot, and immunohistochemistry. ResultsThe study identified FUCA1 and NCKAP1L as significantly enriched in non-metastatic osteosarcoma, with higher expression associated with better patient survival rates. Gene function enrichment was primarily related to immune functions, with positive correlations to macrophage phagocytosis, antigen presentation, and macrophage polarization pathways. Analysis of the immune microenvironment revealed a positive correlation between gene expression and immune scores, with increased presence of macrophages, T cells, and B cells in the high expression group. Single-cell analysis and experimental results confirmed the enrichment of FUCA1 and NCKAP1L in macrophages. ConclusionThe identification of FUCA1 and NCKAP1L as potential prognostic biomarkers suggests their potential for improving patient outcomes. Modulation of macrophages may offer a promising strategy for enhancing the immune microenvironment in osteosarcoma.

Identification of immune-related tumor antigens and immune subtypes in osteosarcoma

PurposeThe development of tumor vaccines has become a hot topic in immunotherapy for osteosarcoma (OS); however, more tumor antigens with stronger immunogenicity need to be identified. MethodsWe downloaded six sets of gene expression profile data from online databases. The overexpressed genes were analyzed, intersected, and used to calculate the immune infiltration abundance in the TARGET OS dataset based on their expression matrix. Potential tumor antigen genes were identified based on whether they exhibited a high correlation with the antigen-presenting cells (APCs). A total of 1330 immune-related genes (IRGs) from the ImmPort website were retrieved based on their expression, and the Consensus Cluster method was used to obtain immune subtypes of the OS samples. Prognosis, immune microenvironment, and sensitivity to drugs were compared among the immune subtypes. ResultsIn total, 680 genes were overexpressed in at least two datasets, of which TREM2, TNFRSF12A, and THY1 were positively correlated with different APCs. Based on the expression matrix of 1330 IRGs in TARGET-OS, two immune subtypes, IS1 and IS2, were identified. The prognosis of the IS1 subtype was better than that of IS2, the expression of immune checkpoint (ICP)-related genes was higher in patients with the IS1 subtype, and immune cell infiltration and sensitivity to 16 drugs were generally higher in IS1 subtype patients. ConclusionWe identified three APC-correlated genes that can be considered to code for potential novel tumor antigens for OS vaccines. Two immune subtypes in patients with OS were identified to implement personalized treatments using mRNA vaccines.

Ultrasound-responsive metal–organic framework-based nanosystem for sonodynamic therapy/amplified ferroptosis/IDO-blockade osteosarcoma immunotherapy

The metastasis and recurrence of osteosarcoma (OS) are significant challenges in its clinical management. Tumor immunogenic cell death (ICD)-induced immunotherapy has been widely investigated to solve these problems. However, achieving sufficient ICD and a robust immune response is challenging for nanoparticle-based OS immunotherapy. Here, we report an ultrasound-responsive metal–organic framework-based nanosystem (MFePCN@1-MT) with sonodynamic therapy (SDT) and 1-methyltryptophan (1-MT) responsive release properties. Under ultrasound irradiation, the nanosystem induces reactive oxygen species (ROS) generation, ferroptosis, and the responsive release of 1-MT, which competitively inhibits indoleamine-2,3-dioxygenase (IDO), promotes further ROS accumulation, and amplifies ferroptosis. Notably, SDT/amplified ferroptosis/IDO blockade synergistically kills OS cells, maximizes the amplified ICD effect, activates dendritic cells (DCs) maturation, inhibits regulatory T lymphocytes (Tregs), and triggers CD4+ T-cell and CD8+ T-cell immune responses. Thus, this nanosystem synergistically inhibits K7M2 primary tumors via SDT/amplified ferroptosis/IDO blockade. In addition, the nanosystem enhances the ICD effect, modulates the immunosuppressive microenvironment, promotes immunity against solid tumors, and inhibits distant metastatic tumor growth. This study combines SDT/amplified ferroptosis/IDO blockade into a single nanomedicine and presents a new strategy for OS immunotherapy.

Abstract 4033: Leukocyte-based biomimetic nanoparticles for combined targeted and immunotherapy in osteosarcoma

Abstract Osteosarcoma is the most diffuse bone cancer in the pediatric population, with most patients showing resistance to therapy. All patients are administered systemic high-dose cytotoxic chemotherapy regimens. Many targeted and immune therapy approaches are currently in clinical trials for treating osteosarcoma, but single treatments are not showing promise. While combined targeted and immunotherapy appears to be a possible avenue, developing solutions for patients who show intolerable toxicity or lack of synergy is critical. Nanoparticles (NPs) have successfully been used to prolong the half-life of drugs, favor extended release, reduce systemic toxicity, and reach beyond biological barriers. Biomimetic NPs represent an emerging class of NPs as a system to mimic naturally occurring processes. One class of biomimetic NPs is leukosomes, leukocyte-based biomimetic NPs that target inflamed tissues. Leukosomes are synthesized by integrating proteins isolated from the membranes of circulating leukocytes in the NPs' wall. Leukosomes' biomolecular profile helps them adhere to tumor-inflamed vasculature and promotes their self-tolerance and ability to evade immune clearance from the mononuclear phagocyte system (MPS). We have demonstrated the feasibility of a "one-two punch" approach for leukosome-mediated bone cancer treatment. Specifically, the first "punch" (a multi tyrosine kinase inhibitor, mTKI) induces an immunogenic response, which is subsequently targeted by leukosomes delivering a second class of compounds (immunomodulating nucleic acids, second "punch"). Indeed, even a single mTKI administration increases the amount of leukosomes localized to tumors, which is amplified by a second dosage in a dose-dependent manner. Importantly, leukosome infiltration was paralleled by an increase in immune infiltration, especially in Cd8+ T-cell abundance and macrophages. After several iterations and protocol adjustments, leukosome compositions and microfluidic parameters have been optimized to load either siRNA or mRNA. Current experiments are optimizing the "second punch" targeting immune checkpoint inhibitors (siRNAs vs. PD1/PDL-1). Interestingly, we showed the leukosomes produced using the membranes of human or mouse macrophages pre-treated with LPS show increased surface concentration of adhesion molecules (e.g., Siglec-1) that further enhance their localization at the inflamed site while decreasing filtration by the MPS. In addition to increased delivery to the tumor site, this strategy reduces the therapeutic strain because it is sequential ("one-two punch") and uses nucleic acids instead of antibodies to target immune checkpoints. Overall, our work describes a novel rationale-based sequential approach that can be paradigm-shifting in the field as it harnesses treatment-induced inflammation to boost intratumoral drug delivery. Citation Format: Gabriele Romano, Binh Ha, Jason T. Yustein, Francesca Taraballi. Leukocyte-based biomimetic nanoparticles for combined targeted and immunotherapy in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4033.

PD-L1, STAT3, IL6, and EGFR Immunoexpressions in High-Grade Osteosarcoma.

Immunotherapy has been widely used in the treatment of various malignancies with satisfactory results. One of the agents for immunotherapy is an inhibitor of programmed cell death-1 and its ligands (PD-1 and PD-L1). However, attempts at utilizing PD-1/PD-L1 immunotherapy in osteosarcoma have not yielded favorable results. This may be due to differences in PD-L1 regulation and the immune landscape in osteosarcoma, as the mechanism is still poorly understood. Therefore, elucidating PD-L1 regulation in osteosarcoma is paramount in order to improve treatment results using immunotherapy. This is a cross-sectional study conducted in the Department of Anatomical Pathology of Saiful Anwar Hospital using 33 paraffin blocks of confirmed cases of osteosarcoma. Immunohistochemical staining using PD-L1, STAT3, IL6, and EGFR was performed. Statistical analyses were subsequently performed on the immunoexpression data of these antibodies. PD-L1, STAT3, IL6, and EGFR expressions were found in 6 (18.2%), 6 (18.2%), 28 (84.8%), and 30 (90.9%) cases, respectively. There were significant correlations between PD-L1 and STAT3 (r = 0.620, p=<0.001), PD-L1 and EGFR (r = 0.449, p=0.009), as well as STAT3 and EGFR (r = 0.351, p=0.045). The existence of a correlation between PD-L1, STAT3, and EGFR indicates the potential role of STAT3 and EGFR in PD-L1 regulation in osteosarcoma, which may become the basis for targeted therapy.

Single-cell and bulk RNA sequencing reveals Anoikis related genes to guide prognosis and immunotherapy in osteosarcoma

Anoikis resistance, a notable factor in osteosarcoma, plays a significant role in tumor invasion and metastasis. This study seeks to identify a distinct gene signature that is specifically associated with the anoikis subcluster in osteosarcoma. Clinical, single-cell, and transcriptional data from TARGET and GEO datasets were used to develop a gene signature for osteosarcoma based on the anoikis subcluster. Univariate Cox and LASSO regression analyses were employed. The signature's predictive value was evaluated using time-dependent ROC and Kaplan–Meier analyses. Functional enrichment analyses and drug sensitivity analyses were conducted. Validation of three modular genes was performed using RT-qPCR and Western blotting. Signature (ZNF583, CGNL1, CXCL13) was developed to predict overall survival in osteosarcoma patients, targeting the anoikis subcluster. The signature demonstrated good performance in external validation. Stratification based on the signature revealed significantly different prognoses. The signature was an independent prognostic factor. The low-risk group showed enhanced immune cell infiltration and improved immune function. Drug sensitivity analysis indicated efficacy of chemotherapy agents. Prognostic nomograms incorporating the signature provided greater predictive accuracy and clinical utility. Signatures related to the anoikis subcluster play a significant role in osteosarcoma progression. Incorporating these findings into clinical decision-making can improve osteosarcoma treatment and patient outcomes.

Advances in immunotherapy for osteosarcoma: a review of emerging treatment strategies

Advances in immunotherapy for osteosarcoma have shown promising results, with the use of monoclonal antibodies and immune checkpoint inhibitors. These strategies are aimed at targeting specific molecules and pathways involved in tumour immune evasion and promoting anti-tumour immune responses. Other emerging immunotherapeutic approaches include autophagy and pyroptosis induction, chimeric antigen receptor T-cell therapy, gadolinium-bisphosphonate nanoparticles and dendritic cell-based vaccines. Continued research into these emerging treatment strategies is essential for developing effective therapies for patients with high-grade osteosarcoma.

Promise and Challenges of T Cell Immunotherapy for Osteosarcoma.

The cure rate for metastatic or relapsed osteosarcoma has not substantially improved over the past decades despite the exploitation of multimodal treatment approaches, allowing long-term survival in less than 30% of cases. Patients with osteosarcoma often develop resistance to chemotherapeutic agents, where personalized targeted therapies should offer new hope. T cell immunotherapy as a complementary or alternative treatment modality is advancing rapidly in general, but its potential against osteosarcoma remains largely unexplored. Strategies incorporating immune checkpoint inhibitors (ICIs), chimeric antigen receptor (CAR) modified T cells, and T cell engaging bispecific antibodies (BsAbs) are being explored to tackle relapsed or refractory osteosarcoma. However, osteosarcoma is an inherently heterogeneous tumor, both at the intra- and inter-tumor level, with no identical driver mutations. It has a pro-tumoral microenvironment, where bone cells, stromal cells, neovasculature, suppressive immune cells, and a mineralized extracellular matrix (ECM) combine to derail T cell infiltration and its anti-tumor function. To realize the potential of T cell immunotherapy in osteosarcoma, an integrated approach targeting this complex ecosystem needs smart planning and execution. Herein, we review the current status of T cell immunotherapies for osteosarcoma, summarize the challenges encountered, and explore combination strategies to overcome these hurdles, with the ultimate goal of curing osteosarcoma with less acute and long-term side effects.

Immunogenic cell death-related classifications guide prognosis and immunotherapy in osteosarcoma

Immunogenic cell death (ICD) is a form of cell death that stimulates the immune system to produce an immune response by releasing tumour-associated antigens and tumour-specific antigens and is considered to play an important role in tumour immunotherapy. In the present study, we identified two ICD-related subtypes in osteosarcoma (OS) by consensus clustering. The ICD-low subtype was associated with favourable clinical outcomes, abundant immune cell infiltration, and high activity of immune response signalling. We also established and validated an ICD-related prognostic model, which could not only be used to predict the overall survival of OS patients but was also found to be closely related to the tumour immune microenvironment of OS patients. Overall, we established a new classification system for OS based on ICD-related genes, which can be used to predict the prognosis of OS patients and to select appropriate immunotherapy drugs.

Combination of IDO inhibitors and platinum(IV) prodrugs reverses low immune responses to enhance cancer chemotherapy and immunotherapy for osteosarcoma.

In recent years, immune checkpoint blockades (ICBs) have made great progress in the treatment of cancer. However, most ICBs have not yet been observed to be satisfactory in the treatment of osteosarcoma. Herein, we designed composite nanoparticles (NP-Pt-IDOi) from a reactive oxygen species (ROS) sensitive amphiphilic polymer (PHPM) with thiol-ketal bonds in the main chain to encapsulate a Pt(IV) prodrug (Pt(IV)-C12) and an indoleamine-(2/3)-dioxygenase (IDO) inhibitor (IDOi, NLG919). Once NP-Pt-IDOi enter the cancer cells, the polymeric nanoparticles could dissociate due to the intracellular ROS, and release Pt(IV)-C12 and NLG919. Pt(IV)-C12 induces DNA damage and activates the cGAS-STING pathway, increasing infiltration of CD8+ T cells in the tumor microenvironment. In addition, NLG919 inhibits tryptophan metabolism and enhances CD8+ T cell activity, ultimately activating anti-tumor immunity and enhancing the anti-tumor effects of platinum-based drugs. NP-Pt-IDOi were shown to have superior anti-cancer activity in vitro and in vivo in mouse models of osteosarcoma, providing a new clinical paradigm for combining chemotherapy with immunotherapy for osteosarcoma.

Clinical significance and immune landscape of a novel ferroptosis-related prognosis signature in osteosarcoma

BackgroundOsteosarcoma is a malignant tumor that usually occurs in adolescents aged 10–20 years and is associated with poor prognosis. Ferroptosis is an iron-dependent cell death mechanism that plays a vital role in cancer.MethodsOsteosarcoma transcriptome data were downloaded from the public database TARGET and from previous studies. A prognostic risk score signature was constructed using bioinformatics analysis, and its efficacy was determined by analyzing typical clinical features. The prognostic signature was then validated with external data. Differences in immune cell infiltration between high- and low-risk groups were analyzed. The potential of the prognostic risk signature as a predictor of immunotherapy response was evaluated using the GSE35640 (melanoma) dataset. Five key genes expression were measured by real-time PCR and western blot in human normal osteoblasts and osteosarcoma cells. Moreover, malignant biological behaviors of osteosarcoma cells were tested by modulating gene expression level.ResultsWe obtained 268 ferroptosis-related genes from the online database FerrDb and published articles. Transcriptome data and clinical information of 88 samples in the TARGET database were used to classify genes into two categories using clustering analysis, and significant differences in survival status were identified. Differential ferroptosis-related genes were screened, and functional enrichment showed that they were associated with HIF-1, T cells, IL17, and other inflammatory signaling pathways. Prognostic factors were identified by univariate Cox regression and LASSO analysis, and a 5-factor prognostic risk score signature was constructed, which was also applicable for external data validation. Experimental validation indicated that the mRNA and protein expression level of MAP3K5, LURAP1L, HMOX1 and BNIP3 decreased significantly, though meanwhile MUC1 increased in MG-63 and SAOS-2 cells compared with hFOB1.19 cells. Cell proliferation and migration ability of SAOS-2 were affected based on alterations of signature genes.ConclusionsSignificant differences in immune cell infiltration between high- and low-risk groups indicated that the five ferroptosis-related prognostic signature was constructed and could be used to predict the response to immunotherapy in osteosarcoma.

Autophagy and its role in osteosarcoma.

Osteosarcoma (OS) is the most common bone malignancy and preferably occurs in children and adolescents. Despite significant advances in surgery and chemotherapy for OS over the past few years, overall survival rates of OS have reached a bottleneck. Thus, extensive researches aimed at developing new therapeutic targets for OS are urgently needed. Autophagy, a conserved process which allows cells to recycle altered or unused organelles and cellular components, has been proven to play a critical role in multiple biological processes in OS. In this article, we summarized the association between autophagy and proliferation, metastasis, chemotherapy, radiotherapy, and immunotherapy of OS, revealing that autophagy-related genes and pathways could serve as potential targets for OS therapy.

The Prognostic Model Established by the Differential Expression Genes Based on CD8+ T Cells to Evaluate the Prognosis and the Response to Immunotherapy in Osteosarcoma.

Osteosarcoma (OS) is a malignant tumor with an extremely poor prognosis, especially in progressive patients. Immunotherapy based on immune checkpoint inhibitors (ICIs) is considered to be a promising treatment option for OS. Due to tumor heterogeneity, only a minority of patients benefit from immunotherapy. Therefore, it is urgent to explore a model that can accurately assess the response of OS to immunotherapy. In this study, we obtained the single-cell RNA sequencing datasets of OS patients from public databases and defined 34 cell clusters by dimensional reduction and clustering analysis. PTPRC was applied to identify immune cell clusters and nonimmune cell clusters. Next, we performed clustering analysis on the immune cell clusters and obtained 25 immune cell subclusters. Immune cells were labeled with CD8A and CD8B to obtain CD8+ T cell clusters. Meanwhile, we extracted the differentially expressed genes (DEGs) of CD8+ T cell clusters and other immune cell clusters. Furthermore, we constructed a prognostic model (CD8-DEG model) based on the obtained DEGs of CD8+ T cells, and verified the excellent predictive ability of this model for the prognosis of OS. Moreover, we further investigated the value of the CD8-DEG model. The results indicated that the risk score of the CD8-DEG model was an independent risk factor for OS patients. Finally, we revealed that the risk score of the CD8-DEG model correlates with the immune profile of OS and can be used to evaluate the response of OS to immunotherapy. In conclusion, our study revealed the critical role of CD8 cells in OS. The risk score model based on CD8-DEGs can provide guidance for prognosis and immunotherapy of OS.

Modulation of immunosuppressive cells and noncoding RNAs as immunotherapy in osteosarcoma

The most common bone cancer is osteosarcoma (OS), which mostly affects children and teenagers. Early surgical resection combined with chemotherapy significantly improves the prognosis of patients with OS. Existing chemotherapies have poor efficacy in individuals with distant metastases or inoperable resection, and these patients may respond better to novel immunotherapies. Immune escape, which is mediated by immunosuppressive cells in the tumour microenvironment (TME), is a major cause of poor OS prognosis and a primary target of immunotherapy. Myeloid-derived suppressor cells, regulatory T cells, and tumour-associated macrophages are the main immunosuppressor cells, which can regulate tumorigenesis and growth on a variety of levels through the interaction in the TME. The proliferation, migration, invasion, and epithelial-mesenchymal transition of OS cells can all be impacted by the expression of non-coding RNAs (ncRNAs), which can also influence how immunosuppressive cells work and support immune suppression in TME. Interferon, checkpoint inhibitors, cancer vaccines, and engineered chimeric antigen receptor (CAR-T) T cells for OS have all been developed using information from studies on the metabolic properties of immunosuppressive cells in TME and ncRNAs in OS cells. This review summarizes the regulatory effect of ncRNAs on OS cells as well as the metabolic heterogeneity of immunosuppressive cells in the context of OS immunotherapies.

Bioinformatics Analysis Reveals an Association between Autophagy, Prognosis, Tumor Microenvironment, and Immunotherapy in Osteosarcoma.

Autophagy is a catabolic pathway involved in the regulation of bone homeostasis. We explore clinical correlation of autophagy-related key molecules to establish risk signature for predicting the prognosis, tumor microenvironment (TME), and immunotherapy response of osteosarcoma. Single cell RNA sequencing data from GSE162454 dataset distinguished malignant cells from normal cells in osteosarcoma. Autophagy-related genes (ARGs) were extracted from the established risk signature of the Molecular Signatures Database of Gene Set Enrichment Analysis (GSEA) by univariate Cox and least absolute shrinkage and selection operator (LASSO) Cox regression analysis. Overall survival (OS), TME score, abundance of infiltrating immune cells, and response to immune-checkpoint blockade (ICB) treatment in patients with different risks were compared based on risk score. Nine ARGs were identified and risk signature was constructed. In all osteosarcoma datasets, the OS was significantly longer in the high-risk patients than low-risk onset. Risk signature significantly stratified clinical outcomes, including OS, metastatic status, and survival status. Risk signature was an independent variable for predicting osteosarcoma OS and showed high accuracy. A nomogram based on risk signature and metastases was developed. The calibration curve confirmed the consistency in 1-year, 3-year, and 5-year predicted OS and the actual OS. The risk score was related to 6 kinds of T cells and macrophages, myeloid-derived suppressor cell, natural killer cell, immune score, and stromal score in TME. The risk signature helped in predicting patients' response to anti-PD1/anti-PD-L1 treatment. The ARGs-led risk signature has important value for survival prediction, risk stratification, tumor microenvironment, and immune response evaluation of osteosarcoma.

Prediction of Prognosis and Immunotherapy of Osteosarcoma Based on Necroptosis-Related lncRNAs.

Background: Osteosarcoma (OS) is the most common primary tumor of bone in adolescents, and its survival rate is generally less than 20% when metastases occur. Necroptosis, a novel form of programmed necrotic cell death distinct from apoptosis, has been increasingly recognized as a promising therapeutic strategy. This study sought to identify long non-coding RNAs (lncRNAs) associated with necrotizing apoptosis to predict prognosis and target drug use to improve patient survival. Methods: Transcriptomic data and clinical data from 85 OS patients with survival time data and expression profiles from 85 random normal adipose tissue samples were extracted from the UCSC Xena website (http://xena.ucsc.edu/). Nine necroptosis-associated differential prognostic lncRNAs were then identified by analysis of variance, correlation analysis, univariate Cox (uni-Cox) regression, and Kaplan–Meier analysis. Then, patients were randomized into training or testing groups. According to uni-Cox, we obtained prognostic lncRNAs in the training group and intersected them with the abovementioned nine lncRNAs to obtain the final necrotizing apoptosis–related differential prognostic lncRNAs (NRlncRNAs). Next, we performed the least absolute shrinkage and selection operator (LASSO) to construct a risk model of NRlncRNAs. Kaplan–Meier analysis, ROC curves, nomograms, calibration curves, and PCA were used to validate and evaluate the models and grouping. We also analyzed the differences in tumor immunity and drugs between risk groups. Results: We constructed a model containing three NRlncRNAs (AL391121.1, AL354919.2, and AP000851.2) and validated its prognostic predictive power. The value of the AUC curve of 1-, 3-, and 5-year survival probability was 0.806, 0.728, and 0.731, respectively. Moreover, we found that the overall survival time of patients in the high-risk group was shorter than that in the low-risk group. GSEA and ssGSEA showed that immune-related pathways were mainly abundant in the low-risk group. We also validated the differential prediction of immune checkpoint expression, tumor immunity, and therapeutic compounds in the two risk groups. Conclusion: Overall, NRlncRNAs have important functions in OS, and these three NRlncRNAs can predict the prognosis of OS and provide guidance for immunotherapy in OS.

Nanoengineering a metal\u2013organic framework for osteosarcoma chemo-immunotherapy by modulating indoleamine-2,3-dioxygenase and myeloid-derived suppressor cells

BackgroundThe high postoperative recurrence rate and refractoriness of relapsed tumors are still a conundrum for the clinical management of osteosarcoma (OS). New therapeutic options are urgently needed. Depriving the nourishment of myeloid-derived suppressor cells is a novel strategy to improve the immunosuppressive tumor microenvironment for enhanced OS therapy.MethodsWe synthesized a hyaluronic acid (HA)-modified metal–organic framework for combinational chemotherapy and immunotherapy of OS. Zeolitic Imidazolate Framework-8 (ZIF-8) was prepared by a one-pot synthetic method, Gemcitabine (Gem) and D-1-Methyltryptophan (D-1-MT) were loaded into the ZIF-8 during the synthesis process to make ZIF-8@Gem/D-1-MT nanoparticles (NPs). The end product (HA/ZIF-8@Gem/D-1-MT NPs) was obtained by HA modification on the surface of ZIF-8@Gem/D-1-MT NPs. The obtained HA/ZIF-8@Gem/D-1-MT NPs have excellent potential as a drug delivery vector for chemotherapy and immunotherapy in vitro and vivo.ResultsThe results indicate that HA/ZIF-8@Gem/D-1-MT NPs were readily taken up by OS cells, and that the Gem and D-1-MT were effectively released into the acidic environment. The HA/ZIF-8@Gem/D-1-MT NPs could efficiently decrease OS cell viability (proliferation, apoptosis, cell cycle, migration and invasion). And HA/ZIF-8@Gem/D-1-MT NPs could reactivate antitumor immunity by inhibiting indoleamine 2,3 dioxygenase and myeloid-derived suppressor cells. Furthermore, animal experiments confirmed that HA/ZIF-8@Gem/D-1-MT NPs could induce intratumoral immune responses and inhibit tumor growth. Additionally, HA/ZIF-8@Gem/D-1-MT NPs have a good safety profile.ConclusionsOur findings demonstrate that the combination of Gem with D-1-MT brings new hope for the improved treatment of OS, while the generation of the nanosystem has increased the application potential and flexibility of this strategy.