Resistance Mechanisms of Anti-PD1/PDL1 Therapy in Solid Tumors

Metastatic Organotropism Differential Treatment Response in Urothelial Carcinoma: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

CONTEXT

The optimal therapeutic agent with respect to metastatic sites is unclear in advanced urothelial carcinoma (UC).

OBJECTIVE

To investigate the metastatic organotropism differential treatment response in patients with advanced or metastatic UC.

EVIDENCE ACQUISITION

A systematic search and network meta-analysis (NMA) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The primary endpoints of interest were the objective response rate, overall survival (OS), and progression-free survival with respect to different metastatic sites.

EVIDENCE SYNTHESIS

Twenty-six trials comprising 9082 patients met our eligibility criteria, and a formal NMA was conducted. Durvalumab plus tremelimumab as first-line systemic therapy was significantly associated with better OS than chemotherapy in visceral metastasis (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.67-0.98). Pembrolizumab as second-line systemic therapy was significantly associated with better OS than chemotherapy in patients with visceral metastasis (HR 0.75, 95% CI 0.60-0.95). Atezolizumab as second-line systemic therapy was significantly associated with better OS than chemotherapy in patients with liver metastasis (in the population of >5% of tumor-infiltrating immune cells) and lymph node metastasis (HR 0.51, 95% CI 0.28-0.96, and HR 0.59, 95% CI 0.37-0.96, respectively).

CONCLUSIONS

Administration of immune-oncology treatments with respect to metastatic sites in patients with advanced or metastatic UC might have a positive impact on survival outcomes in both the first- and the second-line setting. Nevertheless, further investigations focusing on metastatic organotropism differential response with reliable oncological outcomes are needed to identify the optimal management strategy for these patients.

PATIENT SUMMARY

Although the supporting evidence for oncological benefits of therapeutic systemic agents with respect to metastatic sites is not yet strong enough to provide a recommendation in advanced or metastatic urothelial carcinoma, clinicians may take into account tumor organotropism only in discussion with the patient fully informed on the optimal treatment decision to be taken.

The advancements and prospective developments in anti-tumor targeted therapy

Cancer poses a major threat to human health worldwide. The development of anti-tumor materials provides new modalities for cancer diagnosis and treatment. In this review, we comprehensively summarize the research progress and clinical applications of anti-tumor materials. First, we introduce the etiology and pathogenesis of cancer, and the significance and challenges of anti-tumor materials research. Then, we classify anti-tumor materials and discuss their mechanisms of action. After that, we elaborate the research advances and clinical applications of anti-tumor materials, including those targeting tumor cells and therapeutic instruments. Finally, we discuss the future perspectives and challenges in the field of anti-tumor materials. This review aims to provide an overview of the current status of anti-tumor materials research and application, and to offer insights into future directions in this rapidly evolving field, which holds promise for more precise, efficient and customized treatment of cancer.

Dysregulation of tRNA methylation in cancer: Mechanisms and targeting therapeutic strategies

tRNA is the RNA type that undergoes the most modifications among known RNA, and in recent years, tRNA methylation has emerged as a crucial process in regulating gene translation. Dysregulation of tRNA abundance occurs in cancer cells, along with increased expression and activity of tRNA methyltransferases to raise the level of tRNA modification and stability. This leads to hijacking of translation and synthesis of multiple proteins associated with tumor proliferation, metastasis, invasion, autophagy, chemotherapy resistance, and metabolic reprogramming. In this review, we provide an overview of current research on tRNA methylation in cancer to clarify its involvement in human malignancies and establish a theoretical framework for future therapeutic interventions targeting tRNA methylation processes.

M2-type tumor-associated macrophages upregulated PD-L1 expression in cervical cancer via the PI3K/AKT pathway

BACKGROUND AND PURPOSE

PD-1/PD-L1 inhibitors have become a promising therapy. However, the response rate is lower than 30% in patients with cervical cancer (CC), which is related to immunosuppressive components in tumor microenvironment (TME). Tumor-associated macrophages (TAMs), as one of the most important immune cells, are involved in the formation of tumor suppressive microenvironment. Therefore, it will provide a theoretical basis for curative effect improvement about the regulatory mechanism of TAMs on PD-L1 expression.

METHODS

The clinical data and pathological tissues of CC patients were collected, and the expressions of PD-L1, CD68 and CD163 were detected by immunohistochemistry. Bioinformatics was used to analyze the macrophage subtypes involved in PD-L1 regulation. A co-culture model was established to observe the effects of TAMs on the morphology, migration and invasion function of CC cells, and the regulatory mechanism of TAMs on PD-L1.

RESULTS

PD-L1 expression on tumor cells could predict the poor prognosis of patients. And there was a strong correlation between PD-L1 expression with CD163+TAMs infiltration. Similarly, PD-L1 expression was associated with M1/M2-type TAMs infiltration in bioinformatics analysis. The results of cell co-culture showed that M1/M2-type TAMs could upregulate PD-L1 expression, especially M2-type TAMs may elevate the PD-L1 expression via PI3K/AKT pathway. Meanwhile, M1/M2-type TAMs can affect the morphological changes, and enhance migration and invasion abilities of CC cells.

CONCLUSIONS

PD-L1 expression in tumor cells can be used as a prognostic factor and is closely related to CD163+TAMs infiltration. In addition, M2-type TAMs can upregulate PD-L1 expression in CC cells through PI3K/AKT pathway, enhance the migration and invasion capabilities, and affect the tumor progression.

An Updated Review on KRAS Mutation in Lung Cancer (NSCLC) and Its Effects on Human Health

The largest cause of cancer-related fatalities worldwide is lung cancer. In its early stages, lung cancer often exhibits no signs or symptoms. Its signs and symptoms often appear when the condition is advanced. The Kirsten rat sarcoma virus oncogene homolog is one of the most frequently mutated oncogenes found in non-small cell lung cancer. Patients who have these mutations may do worse than those who do not, in terms of survival. To understand the nuances in order to choose the best treatment options for each patient, including combination therapy and potential resistance mechanisms, given the quick development of pharmaceuticals, it is necessary to know the factors that might contribute to this disease. It has been observed that single nucleotide polymorphisms altering let-7 micro-RNA might impact cancer propensity. On the other hand, gefitinib fails to stop the oncogenic protein from directly interacting with phosphoinositide3-kinase, which may explain its resistance towards cancer cells. Additionally, Atorvastatin may be able to overpower gefitinib resistance in these cancer cells that have this mutation regardless of the presence of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha. De novo lipogenesis is also regulated by this virus. To overcome these effects, several targeted therapies have been proposed. One such therapy is to use inhibitors of focal adhesion kinases. When this is inhibited, viral oncogene mutant cancers are effectively stopped because it functions downstream of the virus. Mutant oncoproteins like epidermal growth factor receptor may depend on Heat Shock protein90 chaperones more frequently than they do on natural counterparts that make it more attractive therapeutic target for this virus. Inhibition of the phosphoinositide 3-kinase pathway is frequent in lung cancer, and fabrication of inhibitors against this pathway can also be an effective therapeutic strategy. Blocking programmed cell death ligand1 is another therapy that may help T cells to recognize and eliminate cancerous cells. This homolog is a challenging therapeutic target due to its complex structural makeup and myriad biological characteristics. Thanks to the unrelenting efforts of medical research, with the use of some inhibitors, immunotherapy, and other combination methods, this problem is currently expected to be overcome.

Hybrid Cell Membrane-Based Nanoplatforms for Enhanced Immunotherapy against Cancer and Infectious Diseases

Immunotherapy based on nanoplatforms is a promising approach to treat cancer and infectious diseases, and it has achieved considerable progress in clinical practices. Cell membrane-based nanoplatforms endow nanoparticles with versatile characteristics, such as half-life extension, targeting ability, and immune-system regulation. However, monotypic cell membrane usually fails to provoke strong immune response for immunotherapy while maintaining good biosafety. The integration of different cell-membrane types provides a promising approach to construct multifunctional nanoplatforms for improved immunotherapeutic efficacy by enhancing immunogenicity or targeting function, evading immune clearance, or combining with other therapeutic modalities. In this review, the design principles, preparation strategies, and applications of hybrid cell membrane-based nanoplatforms for cancer and infection immunotherapy are first discussed. Furthermore, the challenges and prospects for the potential clinical translation of hybrid cell membrane-based nanoplatforms are discussed.

Genetically Engineered CLDN18.2 CAR-T Cells Expressing Synthetic PD1/CD28 Fusion Receptors Produced Using a Lentiviral Vector

This study aimed to develop synthetic Claudin18.2 (CLDN18.2) chimeric antigen receptor (CAR)-T (CAR-T) cells as a treatment for advanced gastric cancer using lentiviral vector genetic engineering technology that targets the CLDN18.2 antigen and simultaneously overcomes the immunosuppressive environment caused by programmed cell death protein 1 (PD-1). Synthetic CAR T cells are a promising approach in cancer immunotherapy but face many challenges in solid tumors. One of the major problems is immunosuppression caused by PD-1. CLDN18.2, a gastric-specific membrane protein, is considered a potential therapeutic target for gastric and other cancers. In our study, CLDN18.2 CAR was a second-generation CAR with inducible T-cell costimulatory (CD278), and CLDN18.2-PD1/CD28 CAR was a third-generation CAR, wherein the synthetic PD1/CD28 chimeric-switch receptor (CSR) was added to the second-generation CAR. In vitro, we detected the secretion levels of different cytokines and the killing ability of CAR-T cells. We found that the secretion of cytokines such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) secreted by three types of CAR-T cells was increased, and the killing ability against CLDN18.2-positive GC cells was enhanced. In vivo, we established a xenograft GC model and observed the antitumor effects and off-target toxicity of CAR-T cells. These results support that synthetic anti-CLDN18.2 CAR-T cells have antitumor effect and anti-CLDN18.2-PD1/CD28 CAR could provide a promising design strategy to improve the efficacy of CAR-T cells in advanced gastric cancer.

EGC enhances tumor antigen presentation and CD8+ T cell-mediated antitumor immunity via targeting oncoprotein SND1

The Staphylococcal nuclease and Tudor domain containing 1 (SND1) has been identified as an oncoprotein. Our previous study demonstrated that SND1 impedes the major histocompatibility complex class I (MHC-I) assembly by hijacking the nascent heavy chain of MHC-I to endoplasmic reticulum-associated degradation. Herein, we aimed to identify inhibitors to block SND1-MHC-I binding, to facilitate the MHC-I presentation and tumor immunotherapy. Our findings validated the importance of the K490-containing sites in SND1-MHC-I complex. Through structure-based virtual screening and docking analysis, (-)-Epigallocatechin (EGC) exhibited the highest docking score to prevent the binding of MHC-I to SND1 by altering the spatial conformation of SND1. Additionally, EGC treatment resulted in increased expression levels of membrane-presented MHC-I in tumor cells. The C57BL/6J murine orthotopic melanoma model validated that EGC increases infiltration and activity of CD8+ T cells in both the tumor and spleen. Furthermore, the combination of EGC with programmed death-1 (PD-1) antibody demonstrated a superior antitumor effect. In summary, we identified EGC as a novel inhibitor of SND1-MHC-I interaction, prompting MHC-I presentation to improve CD8+ T cell response within the tumor microenvironment. This discovery presents a promising immunotherapeutic candidate for tumors.

Analysis of tumor microenvironment alterations in partially responsive rectal cancer patients treated with neoadjuvant chemoradiotherapy

PURPOSE

Achieving a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (NCRT) remains a challenge for most patients with rectal cancer. Exploring the potential of combining NCRT with immunotherapy or targeted therapy for those achieving a partial response (PR) offers a promising avenue to enhance treatment efficacy. This study investigated the impact of NCRT on the tumor microenvironment in locally advanced rectal cancer (LARC) patients who exhibited a PR.

METHODS

This was a retrospective, observational study. Five patients demonstrating a PR after neoadjuvant treatment for LARC were enrolled in the study. Biopsy samples before treatment and resected specimens after treatment were stained with a panel of 26 antibodies targeting various immune and tumor-related markers, each labeled with distinct metal tags. The labeled samples were then analyzed using the Hyperion imaging system.

RESULTS

Heterogeneity within the tumor microenvironment was observed both before and after NCRT. Notably, tumor-associated macrophages, CD4 + T cells, CD8 + T cells, CD56 + natural killer cells, tumor-associated neutrophils, cytokeratin, and E-cadherin exhibited slight increase in abundance within the tumor microenvironment following treatment (change ratios = 0.78, 0.2, 0.27, 0.32, 0.17, 0.46, 0.32, respectively). Conversely, the number of CD14 + monocytes, CD19 + B cells, CD45 + CD4 + T cells, collagen I, α-smooth muscle actin, vimentin, and β-catenin proteins displayed significant decreases post-treatment (change ratios = 1.73, 1.92, 1.52, 1.25, 1.52, 1.12, 2.66, respectively). Meanwhile, Foxp3 + regulatory cells demonstrated no significant change (change ratio = 0.001).

CONCLUSIONS

NCRT has diverse effects on various components of the tumor microenvironment in LARC patients who achieve a PR after treatment. Leveraging combination therapies may optimize treatment outcomes in this patient population.

Anti-tumor immunotherapy using engineered bacterial outer membrane vesicles fused to lysosome-targeting chimeras mediated by transferrin receptor

The lysosome-targeting chimera (LYTAC) approach has shown promise for the targeted degradation of secreted and membrane proteins via lysosomes. However, there have been challenges in design, development, and targeting. Here, we have designed a genetically engineered transferrin receptor (TfR)-mediated lysosome-targeting chimera (TfR-LYTAC) that is efficiently internalized via TfR-mediate endocytosis and targets PD-L1 for lysosomal degradation in cultured cells but not in vivo due to short half-life and poor tumor targeting. A delivery platform was developed by fusing TfR-LYTAC to the surface of bacterial outer membrane vesicles (OMVs). The engineered OMV-LYTAC combines PD-1/PD-L1 pathway inhibition with LYTAC and immune activation by bacterial OMVs. OMV-LYTAC significantly reduced tumor growth in vivo. We have provided a modular and simple genetic strategy for lysosomal degradation as well as a delivery platform for in vivo tumor targeting. The study paves the way for the targeting and degradation of extracellular proteins using the TfR-LYTAC system.

Advances of ultrasound in tumor immunotherapy

Immunotherapy has become a revolutionary method for treating tumors, offering new hope to cancer patients worldwide. Immunotherapy strategies such as checkpoint inhibitors, chimeric antigen receptor T-cell (CAR-T) therapy, and cancer vaccines have shown significant potential in clinical trials. Despite the promising results, there are still limitations that impede the overall effectiveness of immunotherapy; the response to immunotherapy is uneven, the response rate of patients is still low, and systemic immune toxicity accompanied with tumor cell immune evasion is common. Ultrasound technology has evolved rapidly in recent years and has become a significant player in tumor immunotherapy. The introductions of high intensity focused ultrasound and ultrasound-stimulated microbubbles have opened doors for new therapeutic strategies in the fight against tumor. This paper explores the revolutionary advancements of ultrasound combined with immunotherapy in this particular field.

The evolving role of immune checkpoint inhibitors in cervical and endometrial cancer

The introduction of immune checkpoint inhibitors (ICIs) has revolutionized the treatment landscape for numerous tumor types, including cervical and endometrial cancers. Multiple ICIs against programmed cell death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) have demonstrated encouraging outcomes in controlled clinical studies for advanced cervical and endometrial cancers. For advanced cervical cancer, approved ICIs as second-line treatment include cemiplimab, nivolumab, and pembrolizumab as single agents. In the first-line treatment setting, options include pembrolizumab alone or in combination with bevacizumab, as well as atezolizumab combined with a backbone platinum-based chemotherapy plus bevacizumab. Additionally, for locally advanced cervical cancer, pembrolizumab is recommended alongside concurrent chemoradiotherapy. For endometrial cancer, pembrolizumab monotherapy, pembrolizumab in combination with lenvatinib, and dostarlimab are currently approved as second-line treatment options. Moreover, either dostarlimab or pembrolizumab can be added to first-line platinum-based chemotherapy for mismatch repair deficient malignancies. Although the inclusion of these agents in clinical practice has led to improved overall response rates and survival outcomes, many patients still lack benefits, possibly due to multiple intrinsic and adaptive resistance mechanisms to immunotherapy. This review aims to highlight the rationale for utilizing ICIs and their current role, while also delineating the proposed mechanisms of resistance to ICIs in cervical and endometrial cancer.

Immunological synapse formation between T regulatory cells and cancer-associated fibroblasts promotes tumour development

Cancer-associated fibroblasts (CAFs) have emerged as a dominant non-hematopoietic cell population in the tumour microenvironment, serving diverse functions in tumour progression. However, the mechanisms via which CAFs influence the anti-tumour immunity remain poorly understood. Here, using multiple tumour models and biopsies from cancer patients, we report that α-SMA+ CAFs can form immunological synapses with Foxp3+ regulatory T cells (Tregs) in tumours. Notably, α-SMA+ CAFs can phagocytose and process tumour antigens and exhibit a tolerogenic phenotype which instructs movement arrest, activation and proliferation in Tregs in an antigen-specific manner. Moreover, α-SMA+ CAFs display double-membrane structures resembling autophagosomes in their cytoplasm. Single-cell transcriptomic data showed an enrichment in autophagy and antigen processing/presentation pathways in α-SMA-expressing CAF clusters. Conditional knockout of Atg5 in α-SMA+ CAFs promoted inflammatory re-programming in CAFs, reduced Treg cell infiltration and attenuated tumour development. Overall, our findings reveal an immunosuppressive mechanism entailing the formation of synapses between α-SMA+ CAFs and Tregs in an autophagy-dependent manner.

Construction and Application of a PD-L1-Targeted Multimodal Diagnostic and Dual-Functional Theranostics Nanoprobe

Background

In recent years, PD-L1 has been primarily utilized as an immune checkpoint marker in cancer immunotherapy. However, due to tumor heterogeneity, the response rate to such therapies often falls short of expectations. In addition to its role in immunotherapy, PD-L1 serves as a specific target on the surface of tumor cells for targeted diagnostic and therapeutic interventions. There is an absence of a fully developed PD-L1-targeted diagnostic and therapeutic probe for clinical use, which constrains the exploration and clinical exploitation of this target.

Methods and Results

In this study, we engineered a PD-L1-targeted probe with multimodal imaging and dual therapeutic functionalities utilizing organic melanin nanoparticles. Functionalization with the WL12-SH peptide endowed the nanoprobe with specific targeting capabilities. Subsequent radiolabeling with 89Zr (half-life: 100.8 hours) and chelation of Mn2+ ions afforded the probe the capacity for simultaneous PET and MRI imaging modalities. Cellular uptake assays revealed pronounced specificity, with -positive cells exhibiting significantly higher uptake than -negative counterparts (p < 0.05). Dual-modal PET/MRI imaging delineated rapid and sustained accumulation at the neoplastic site, yielding tumor-to-non-tumor (T/NT) signal ratios at 24 hours post-injection of 16.67±3.45 for PET and 6.63±0.64 for MRI, respectively. We conjugated the therapeutic radionuclide 131I (half-life: 8.02 days) to the construct and combined low-dose radiotherapy and photothermal treatment (PTT), culminating in superior antitumor efficacy while preserving a high safety profile. The tumors in the cohort receiving the dual-modality therapy exhibited significantly reduced volume and weight compared to those in the control and monotherapy groups.

Conclusion

We developed and applied a novel -targeted multimodal theranostic nanoprobe, characterized by its high specificity and superior imaging capabilities as demonstrated in PET/MRI modalities. Furthermore, this nanoprobe facilitates potent therapeutic efficacy at lower radionuclide doses when used in conjunction with PTT.

Circ_0027791 contributes to the growth and immune evasion of hepatocellular carcinoma via the miR-496/programmed cell death ligand 1 axis in an m6A-dependent manner

Emerging evidence indicates the critical roles of circular RNAs in the development of multiple cancers, containing hepatocellular carcinoma (HCC). Herein, our present research reported the biological function and mechanism of circ_0027791 in HCC progression. Circ_0027791, microRNA-496 (miR-496), programmed cell death ligand 1 (PDL1), and methyltransferase-like 3 (METTL3) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, proliferation, invasion, and sphere formation ability were detected using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, 5-ethynyl-2'-deoxyuridine, transwell, and sphere formation assays. Macrophage polarization was detected using flow cytometry assay. To understand the role of circ_0027791 during the immune escape, HCC cells were cocultured with peripheral blood mononuclear cells or cytokine-induced killer (CIK) cells in vitro. A xenograft mouse model was applied to assess the function of circ_0027791 in vivo. After prediction using circinteractome and miRDB, the binding between miR-496 and circ_0027791 or PDL1 was validated based on a dual-luciferase reporter assay. Interaction between METTL3 and circ_0027791 was determined using methylated RNA immunoprecipitation (MeRIP)-qPCR, RIP-qPCR, and RNA pull-down assays. Circ_0027791, PDL1, and METTL3 expression were upregulated, and miR-496 was decreased in HCC patients and cells. Moreover, circ_0027791 knockdown might repress proliferation, invasion, sphere formation, M2 macrophage polarization, and antitumor immune response. Circ_0027791 knockdown repressed HCC tumor growth in vivo. In mechanism, circ_0027791 functioned as a sponge for miR-496 to increase PDL1 expression. In addition, METTL3 mediated the m6A methylation of circ_0027791 and stabilized its expression. METTL3-induced circ_0027791 facilitated HCC cell progression partly regulating the miR-496/PDL1 axis, which provided a new prognostic and therapeutic marker for HCC.

Dissecting the stability of Atezolizumab with renewable amino acid-based ionic liquids: Colloidal stability and anticancer activity under thermal stress

Monoclonal antibodies (mAbs) have revolutionised the biopharmaceutical market. Being proteinaceous, mAbs are prone to chemical and physical instabilities. Various approaches were attempted to stabilise proteins against degradation factors. Ionic liquids (ILs) and deep eutectic solvents (DESs) have been established as green solvents for ever-increasing pharmaceutical and biopharmaceutical applications. Hence, amino acid (AA)-based ILs, were used for the first time, for mAb stabilisation. Choline (Ch)-based DESs were also utilised for comparison purposes. The prepared ILs and DESs were utilised to stabilise Atezolizumab (Amab, anti-PDL-1 mAb). The formulations of Amab in ILs and DESs were incubated at room temperature, 45 or 55 °C. Following this, the structural stability of Amab was appraised. Interestingly, Ch-Valine retained favourable structural stability of Amab with minimal detected aggregation or degradation as confirmed by UV-visible spectroscopy and protein Mass Spectroscopy. The measured hydrodynamic diameter of Amab in Ch-Valine ranged from 10.40 to 11.65 nm. More interestingly, the anticancer activity of Amab was evaluated, and Ch-Valine was found to be optimum in retaining the activity of Amab when compared to other formulations, including the control Amab sample. Collectively, this study has spotlighted the advantages of adopting the Ch-AA ILs for the structural and functional stabilising of mAbs.

Unveiling the promise of PD1/PD-L1: A new dawn in immunotherapy for cholangiocarcinoma

Cholangiocarcinoma (CCA), a rare yet notably aggressive cancer, has experienced a surge in incidence in recent years. Presently, surgical resection remains the most effective curative strategy for CCA. Nevertheless, a majority of patients with CCA are ineligible for surgical removal at the time of diagnosis. For advanced stages of CCA, the combination of gemcitabine and cisplatin is established as the standard chemotherapy regimen. Despite this, treatment efficacy is often hindered by the development of resistance. In recent times, immune checkpoint inhibitors, particularly those that block programmed death 1 and its ligand (PD1/PD-L1), have emerged as promising strategies against a variety of cancers and are being increasingly integrated into the therapeutic landscape of CCA. A growing body of research supports that the use of PD1/PD-L1 monoclonal antibodies in conjunction with chemotherapy may significantly improve patient outcomes. This article seeks to meticulously review the latest studies on PD1/PD-L1 involvement in CCA, delving into their expression profiles, prognostic significance, contribution to oncogenic processes, and their potential clinical utility.

Bioconjugated Antibody-Trojan Immune Converter Enhance Cancer Immunotherapy with Minimized Toxicity by Programmed Two-Step Immunomodulation of Myeloid Cells

Current immune checkpoint blockade therapy (ICBT) predominantly targets T cells to harness the antitumor effects of adaptive immune system. However, the effectiveness of ICBT is reduced by immunosuppressive innate myeloid cells in tumor microenvironments (TMEs). Toll-like receptor 7/8 agonists (TLR7/8a) are often used to address this problem because they can reprogram myeloid-derived suppressor cells (MDSCs) and tumor-associated M2 macrophages, and boost dendritic cell (DC)-based T-cell generation; however, the systemic toxicity of TLR7/8a limits its clinical translation. Here, to address this limitation and utilize the effectiveness of TLR7/8a, this work suggests a programmed two-step activation strategy via Antibody-Trojan Immune Converter Conjugates (ATICC) that specifically targets myeloid cells by anti-SIRPα followed by reactivation of transiently inactivated Trojan TLR7/8a after antibody-mediated endocytosis. ATICC blocks the CD47-SIRPα ("don't eat me" signal), enhances phagocytosis, reprograms M2 macrophages and MDSCs, and increases cross-presentation by DCs, resulting in antigen-specific CD8+ T-cell generation in tumor-draining lymph nodes and TME while minimizing systemic toxicity. The local or systemic administration of ATICC improves ICBT responsiveness through reprogramming of the immunosuppressive TME, increased infiltration of antigen-specific CD8+ T cells, and antibody-dependent cellular phagocytosis. These results highlight the programmed and target immunomodulation via ATICC could enhance cancer immunotherapy with minimized systemic toxicities.

High MAL2 expression predicts shorter survival in women with triple-negative breast cancer

INTRODUCTION

Due to its lack of conventional surface receptors, triple-negative breast cancer (TNBC) is inherently resistant to most targeted therapies. MAL2 overexpression prompts endocytosis, conferring resistance to novel therapeutics. This study explores the role of MAL2 and PD-L1 in TNBC patients' prognosis.

METHODS

We performed immunohistochemical analysis on 111 TNBC samples collected from 76 patients and evaluated the expression of MAL2 and PD-1. We expanded the study by including The Cancer Genome Atlas (TCGA) cohort.

RESULTS

MAL2 expression did not correlate with stage, grade, tumor size, lymph node invasion, metastasis, and PD-1 expression. Patients with high MAL2 had significantly lower 5-year survival rates (71.33% vs. 89.59%, p = 0.0224). In the tissue microarray cohort (TMA), node invasions, size, recurrence, and low MAL2 (HR 0.29 [CI 95% 0.087-0.95]; p < 0.05) predicted longer patients' survival. In the TCGA cohort, patients with low MAL2 had significantly longer overall survival and disease-specific survival than patients with high MAL2. Older age and high MAL2 expression were the only independent predictors of shorter patient survival in the BRCA TCGA cohort.

CONCLUSION

High MAL2 predicts unfavorable prognosis in triple-negative breast cancer, and its expression is independent of PD-1 levels and clinicopathological features of TNBC.

Cross-Talks between Raf Kinase Inhibitor Protein and Programmed Cell Death Ligand 1 Expressions in Cancer: Role in Immune Evasion and Therapeutic Implications

Innovations in cancer immunotherapy have resulted in the development of several novel immunotherapeutic strategies that can disrupt immunosuppression. One key advancement lies in immune checkpoint inhibitors (ICIs), which have shown significant clinical efficacy and increased survival rates in patients with various therapy-resistant cancers. This immune intervention consists of monoclonal antibodies directed against inhibitory receptors (e.g., PD-1) on cytotoxic CD8 T cells or against corresponding ligands (e.g., PD-L1/PD-L2) overexpressed on cancer cells and other cells in the tumor microenvironment (TME). However, not all cancer cells respond-there are still poor clinical responses, immune-related adverse effects, adaptive resistance, and vulnerability to ICIs in a subset of patients with cancer. This challenge showcases the heterogeneity of cancer, emphasizing the existence of additional immunoregulatory mechanisms in many patients. Therefore, it is essential to investigate PD-L1's interaction with other oncogenic genes and pathways to further advance targeted therapies and address resistance mechanisms. Accordingly, our aim was to investigate the mechanisms governing PD-L1 expression in tumor cells, given its correlation with immune evasion, to uncover novel mechanisms for decreasing PD-L1 expression and restoring anti-tumor immune responses. Numerous studies have demonstrated that the upregulation of Raf Kinase Inhibitor Protein (RKIP) in many cancers contributes to the suppression of key hyperactive pathways observed in malignant cells, alongside its broadening involvement in immune responses and the modulation of the TME. We, therefore, hypothesized that the role of PD-L1 in cancer immune surveillance may be inversely correlated with the low expression level of the tumor suppressor Raf Kinase Inhibitor Protein (RKIP) expression in cancer cells. This hypothesis was investigated and we found several signaling cross-talk pathways between the regulations of both RKIP and PD-L1 expressions. These pathways and regulatory factors include the MAPK and JAK/STAT pathways, GSK3β, cytokines IFN-γ and IL-1β, Sox2, and transcription factors YY1 and NFκB. The pathways that upregulated PD-L1 were inhibitory for RKIP expression and vice versa. Bioinformatic analyses in various human cancers demonstrated the inverse relationship between PD-L1 and RKIP expressions and their prognostic roles. Therefore, we suspect that the direct upregulation of RKIP and/or the use of targeted RKIP inducers in combination with ICIs could result in a more targeted anti-tumor immune response-addressing the therapeutic challenges related to PD-1/PD-L1 monotherapy alone.

ATG-101 Is a Tetravalent PD-L1×4-1BB Bispecific Antibody That Stimulates Antitumor Immunity through PD-L1 Blockade and PD-L1-Directed 4-1BB Activation

Immune checkpoint inhibitors (ICI) have transformed cancer treatment. However, only a minority of patients achieve a profound response. Many patients are innately resistant while others acquire resistance to ICIs. Furthermore, hepatotoxicity and suboptimal efficacy have hampered the clinical development of agonists of 4-1BB, a promising immune-stimulating target. To effectively target 4-1BB and treat diseases resistant to ICIs, we engineered ATG-101, a tetravalent "2+2″ PD-L1×4-1BB bispecific antibody. ATG-101 bound PD-L1 and 4-1BB concurrently, with a greater affinity for PD-L1, and potently activated 4-1BB+ T cells when cross-linked with PD-L1-positive cells. ATG-101 activated exhausted T cells upon PD-L1 binding, indicating a possible role in reversing T-cell dysfunction. ATG-101 displayed potent antitumor activity in numerous in vivo tumor models, including those resistant or refractory to ICIs. ATG-101 greatly increased the proliferation of CD8+ T cells, the infiltration of effector memory T cells, and the ratio of CD8+ T/regulatory T cells in the tumor microenvironment (TME), rendering an immunologically "cold" tumor "hot." Comprehensive characterization of the TME after ATG-101 treatment using single-cell RNA sequencing further revealed an altered immune landscape that reflected increased antitumor immunity. ATG-101 was well tolerated and did not induce hepatotoxicity in non-human primates. According to computational semimechanistic pharmacology modeling, 4-1BB/ATG-101/PD-L1 trimer formation and PD-L1 receptor occupancy were both maximized at around 2 mg/kg of ATG-101, providing guidance regarding the optimal biological dose for clinical trials. In summary, by localizing to PD-L1-rich microenvironments and activating 4-1BB+ immune cells in a PD-L1 cross-linking-dependent manner, ATG-101 safely inhibits growth of ICI resistant and refractory tumors.

SIGNIFICANCE

The tetravalent PD-L1×4-1BB bispecific antibody ATG-101 activates 4-1BB+ T cells in a PD-L1 cross-linking-dependent manner, minimizing the hepatotoxicity of existing 4-1BB agonists and suppressing growth of ICI-resistant tumors. See related commentary by Ha et al., p. 1546.

Deciphering and overcoming Anti-PD-1 resistance in Melanoma: A comprehensive review of Mechanisms, biomarker Developments, and therapeutic strategies

Worldwide, tens of thousands of people die from melanoma each year, making it the most frequently fatal form of cutaneous cancer. Immunotherapeutic advancements, particularly with anti-PD-1 medications, have significantly enhanced treatment outcomes over recent decades. With the broad application of anti-PD-1 therapies, insights into the mechanisms of resistance have evolved. Despite the development of combination treatments and early predictive biomarkers, a comprehensive synthesis of these advancements is absent in the current literature. This review underscores the prevailing knowledge of anti-PD-1 resistance mechanisms and underscores the critical role of robust predictive biomarkers in stratifying patients for targeted combinations of anti-PD-1 and other conventional or innovative therapeutic approaches. Additionally, we offer insights that may shape future melanoma treatment strategies.

Unlocking PD-1 antibody resistance: The MUC1 DNA vaccine augments CD8+ T cell infiltration and attenuates tumour suppression

In light of increasing resistance to PD1 antibody therapy among certain patient populations, there is a critical need for in-depth research. Our study assesses the synergistic effects of a MUC1 DNA vaccine and PD1 antibody for surmounting PD1 resistance, employing a murine CT26/MUC1 colon carcinoma model for this purpose. When given as a standalone treatment, PD1 antibodies showed no impact on tumour growth. Additionally, there was no change observed in the intra-tumoural T-cell ratios or in the functionality of T-cells. In contrast, the sole administration of a MUC1 DNA vaccine markedly boosted the cytotoxicity of CD8+ T cells by elevating IFN-γ and granzyme B production. Our compelling evidence highlights that combination therapy more effectively inhibited tumour growth and prolonged survival compared to either monotherapy, thus mitigating the limitations intrinsic to single-agent therapies. This enhanced efficacy was driven by a significant alteration in the tumour microenvironment, skewing it towards pro-immunogenic conditions. This assertion is backed by a raised CD8+/CD4+ T-cell ratio and a decrease in immunosuppressive MDSC and Treg cell populations. On the mechanistic front, the synergistic therapy amplified expression levels of CXCL13 in tumours, subsequently facilitating T-cell ingress into the tumour setting. In summary, our findings advocate for integrated therapy as a potent mechanism for surmounting PD1 antibody resistance, capitalizing on improved T-cell functionality and infiltration. This investigation affords critical perspectives on enhancing anti-tumour immunity through the application of innovative therapeutic strategies.

Immunotherapy for colorectal cancer: insight from inherited genetics

Immunotherapy shows efficacy for multiple cancer types and potential for expanded use. However, current immune checkpoint inhibitors (ICIs) are ineffective against microsatellite-stable colorectal cancer (CRC), which is more commonly diagnosed. Immunotherapy strategies for non-responsive CRC, including new targets and new combination therapies, are being tested to address this need. Importantly, a subset of inherited germline genetic variants associated with CRC risk are predicted to regulate genes with immune functions, including genes related to existing ICIs, as well as new potential targets in the major histocompatibility complex (MHC) region and immunoregulatory cytokines. We review discoveries in the inherited genetics of CRC related to the immune system and draw connections with ongoing developments and emerging immunotherapy targets.

PDL1 immunohistochemistry in canine neoplasms: Validation of commercial antibodies, standardization of evaluation, and scoring systems

Immuno-oncology research has brought to light the paradoxical role of immune cells in the induction and elimination of cancer. Programmed cell death protein 1 (PD1), expressed by tumor-infiltrating lymphocytes, and programmed cell death ligand 1 (PDL1), expressed by tumor cells, are immune checkpoint proteins that regulate the antitumor adaptive immune response. This study aimed to validate commercially available PDL1 antibodies in canine tissue and then, applying standardized methods and scoring systems used in human pathology, evaluate PDL1 immunopositivity in different types of canine tumors. To demonstrate cross-reactivity, a monoclonal antibody (22C3) and polyclonal antibody (cod. A1645) were tested by western blot. Cross-reactivity in canine tissue cell extracts was observed for both antibodies; however, the polyclonal antibody (cod. A1645) demonstrated higher signal specificity. Canine tumor histotypes were selected based on the human counterparts known to express PDL1. Immunohistochemistry was performed on 168 tumors with the polyclonal anti-PDL1 antibody. Only membranous labeling was considered positive. PDL1 labeling was detected both in neoplastic and infiltrating immune cells. The following tumors were immunopositive: melanomas (17 of 17; 100%), renal cell carcinomas (4 of 17; 24%), squamous cell carcinomas (3 of 17; 18%), lymphomas (2 of 14; 14%), urothelial carcinomas (2 of 18; 11%), pulmonary carcinomas (2 of 20; 10%), and mammary carcinomas (1 of 31; 3%). Gastric (0 of 10; 0%) and intestinal carcinomas (0 of 24; 0%) were negative. The findings of this study suggest that PDL1 is expressed in some canine tumors, with high prevalence in melanomas.

USP24-i-101 targeting of USP24 activates autophagy to inhibit drug resistance acquired during cancer therapy

Drug resistance in cancer therapy is the major reason for poor prognosis. Addressing this clinically unmet issue is important and urgent. In this study, we found that targeting USP24 by the specific USP24 inhibitors, USP24-i and its analogues, dramatically activated autophagy in the interphase and mitotic periods of lung cancer cells by inhibiting E2F4 and TRAF6, respectively. USP24 functional knockout, USP24C1695A, or targeting USP24 by USP24-i-101 inhibited drug resistance and activated autophagy in gefitinib-induced drug-resistant mice with doxycycline-induced EGFRL858R lung cancer, but this effect was abolished after inhibition of autophagy, indicating that targeting USP24-mediated induction of autophagy is required for inhibition of drug resistance. Genomic instability and PD-L1 levels were increased in drug resistant lung cancer cells and were inhibited by USP24-i-101 treatment or knockdown of USP24. In addition, inhibition of autophagy by bafilomycin-A1 significantly abolished the effect of USP24-i-101 on maintaining genomic integrity, decreasing PD-L1 and inhibiting drug resistance acquired in chemotherapy or targeted therapy. In summary, an increase in the expression of USP24 in cancer cells is beneficial for the induction of drug resistance and targeting USP24 by USP24-i-101 optimized from USP24-i inhibits drug resistance acquired during cancer therapy by increasing PD-L1 protein degradation and genomic stability in an autophagy induction-dependent manner.

Prognostic Value of HHLA2 in Patients with Solid Tumors: A Meta-Analysis

HHLA2 is a checkpoint from the B7 family that can play a co-stimulatory or co-inhibitory role in cancer, depending on the binding receptor. The aim of this meta-analysis was to assess the relationship between HHLA2 levels and its impact on the prognosis of patients with solid cancers. The study used data from PubMed, Embase, Web of Science (WOS), Cochrane and SCOPUS databases. The R studio software was used for the data analysis. The study assessed overall survival (OS), disease-specific survival (DSS), progression-free survival (PFS), recurrence-free survival (RFS), and disease-free survival (DFS) by pooling appropriate hazard ratios (HR). Eighteen studies (2880 patients' data) were included. High expression of HHLA2 was associated with worse OS (HR = 1.58, 95% CI: 1.23-2.03), shorter RFS (HR = 1.95, 95% CI: 1.38-2.77) and worse DFS (HR = 1.45, 95% CI: 1.01-2.09) in patients with solid cancers. The current study suggests that high expression of HHLA2 is associated with poorer prognosis in patients with solid cancers.

The Role of Cdo1 in Ferroptosis and Apoptosis in Cancer

Cysteine dioxygenase type 1 (Cdo1) is a tumor suppressor gene. It regulates the metabolism of cysteine, thereby influencing the cellular antioxidative capacity. This function puts Cdo1 in a prominent position to promote ferroptosis and apoptosis. Cdo1 promotes ferroptosis mainly by decreasing the amounts of antioxidants, leading to autoperoxidation of the cell membrane through Fenton reaction. Cdo1 promotes apoptosis mainly through the product of cysteine metabolism, taurine, and low level of antioxidants. Many cancers exhibit altered function of Cdo1, underscoring its crucial role in cancer cell survival. Genetic and epigenetic alterations have been found, with methylation of Cdo1 promoter as the most common mutation. The fact that no cancer was found to be caused by altered Cdo1 function alone indicates that the tumor suppressor role of Cdo1 is mild. By compiling the current knowledge about apoptosis, ferroptosis, and the role of Cdo1, this review suggests possibilities for how the mild anticancer role of Cdo1 could be harnessed in new cancer therapies. Here, developing drugs targeting Cdo1 is considered meaningful in neoadjuvant therapies, for example, helping against the development of anti-cancer drug resistance in tumor cells.

A2AR-mediated CXCL5 upregulation on macrophages promotes NSCLC progression via NETosis

Tumor-associated macrophages (TAMs) are abundant in tumors and interact with tumor cells, leading to the formation of an immunosuppressive microenvironment and tumor progression. Although many studies have explored the mechanisms underlying TAM polarization and its immunosuppressive functions, understanding of its progression remains limited. TAMs promote tumor progression by secreting cytokines, which subsequently recruit immunosuppressive cells to suppress the antitumor immunity. In this study, we established an in vitro model of macrophage and non-small cell lung cancer (NSCLC) cell co-culture to explore the mechanisms of cell-cell crosstalk. We observed that in NSCLC, the C-X-C motif chemokine ligand 5 (CXCL5) was upregulated in macrophages because of the stimulation of A2AR by adenosine. Adenosine was catalyzed by CD39 and CD73 in macrophages and tumor cells, respectively. Nuclear factor kappa B (NFκB) mediated the A2AR stimulation of CXCL5 upregulation in macrophages. Additionally, CXCL5 stimulated NETosis in neutrophils. Neutrophil extracellular traps (NETs)-treated CD8+ T cells exhibited upregulation of exhaustion-related and cytosolic DNA sensing pathways and downregulation of effector-related genes. However, A2AR inhibition significantly downregulated CXCL5 expression and reduced neutrophil infiltration, consequently alleviating CD8+ T cell dysfunction. Our findings suggest a complex interaction between tumor and immune cells and its potential as therapeutic target.

New advances in the treatment of chondrosarcoma under the PD-1/PD-L1 pathway

ABSTRACT

Bone sarcomas encompass a group of spontaneous mesenchymal malignancies, among which osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma are the most common subtypes. Chondrosarcoma, a relatively prevalent malignant bone tumor that originates from chondrocytes, is characterized by endogenous cartilage ossification within the tumor tissue. Despite the use of aggressive treatment approaches involving extensive surgical resection, chemotherapy, and radiotherapy for patients with osteosarcoma, chondrosarcoma, and chordoma, limited improvements in patient outcomes have been observed. Furthermore, resistance to chemotherapy and radiation therapy has been observed in chondrosarcoma and chordoma cases. Consequently, novel therapeutic approaches for bone sarcomas, including chondrosarcoma, need to be uncovered. Recently, the emergence of immunotherapy and immune checkpoint inhibitors has garnered attention given their clinical success in various diverse types of cancer, thereby prompting investigations into their potential for managing chondrosarcoma. Considering that circumvention of immune surveillance is considered a key factor in the malignant progression of tumors and that immune checkpoints play an important role in modulating antitumor immune effects, blockers or inhibitors targeting these immune checkpoints have become effective therapeutic tools for patients with tumors. One such checkpoint receptor implicated in this process is programmed cell death protein-1 (PD-1). The association between PD-1 and programmed cell death ligand-1 (PD-L1) and cancer progression in humans has been extensively studied, highlighting their remarkable potential as biomarkers for cancer treatment. This review comprehensively examines available studies on current chondrosarcoma treatments and advancements in anti-PD-1/PD-L1 blockade therapy for chondrosarcoma.

An innovative antibody fusion protein targeting PD-L1, VEGF and TGF-β with enhanced antitumor efficacies

Immunosuppressive pathways in the tumor microenvironment (TME) are inextricably linked to tumor progression. Mono-therapeutics of immune checkpoint inhibitors (ICIs, e.g. antibodies against programmed cell death protein-1/programmed cell death ligand-1, PD-1/PD-L1) is prone to immune escape while combination therapeutics tends to cause high toxicity and side effects. Therefore, using multi-functional molecules to target multiple pathways simultaneously is becoming a new strategy for cancer therapies. Here, we developed a trifunctional fusion protein, DR30206, composed of Bevacizumab (an antibody against VEGF), and a variable domain of heavy chain of heavy chain antibody (VHH) against PD-L1 and the extracellular domain (ECD) protein of TGF-β receptor II (TGF-β RII), which are fused to the N- and C-terminus of Bevacizumab, respectively. The original intention of DR30206 design was to enhance the immune responses pairs by targeting PD-L1 while inhibiting VEGF and TGF-β in the TME. Our data demonstrated that DR30206 exhibits high antigen-binding affinities and efficient blocking capabilities, the principal drivers of efficacy in antibody therapy. Furthermore, the capability of eliciting antibody-dependent cellular cytotoxicity (ADCC) and mixed lymphocyte reaction (MLR) provides a greater possibility to enhance the immune response. Finally, in vivo experiments showed that the antitumor activity of DR30206 was superior to those of monoclonal antibody of PD-L1 or VEGF, PD-L1 and TGF-β bispecific antibody or the combination inhibition of PD-L1 and VEGF. Our findings suggest there is a great potential for DR30206 to become a therapeutic for the treatment of multiple cancer types, especially lung cancer, colon adenocarcinoma and breast carcinoma.

Therapeutic approaches to enhance natural killer cell cytotoxicity

Enhancing the cytotoxicity of natural killer (NK) cells has emerged as a promising strategy in cancer immunotherapy, due to their pivotal role in immune surveillance and tumor clearance. This literature review provides a comprehensive overview of therapeutic approaches designed to augment NK cell cytotoxicity. We analyze a wide range of strategies, including cytokine-based treatment, monoclonal antibodies, and NK cell engagers, and discuss criteria that must be considered when selecting an NK cell product to combine with these strategies. Furthermore, we discuss the challenges and limitations associated with each therapeutic strategy, as well as the potential for combination therapies to maximize NK cell cytotoxicity while minimizing adverse effects. By exploring the wealth of research on this topic, this literature review aims to provide a comprehensive resource for researchers and clinicians seeking to develop and implement novel therapeutic strategies that harness the full potential of NK cells in the fight against cancer. Enhancing NK cell cytotoxicity holds great promise in the evolving landscape of immunotherapy, and this review serves as a roadmap for understanding the current state of the field and the future directions in NK cell-based therapies.

Advances in tumor immune microenvironment of head and neck squamous cell carcinoma: A review of literature

Squamous cell carcinoma is seen as principal malignancy of head and neck. Tumor immune microenvironment plays a vital role in the occurrence, development and treatment of head and neck squamous cell carcinoma (HNSCC). The effect of immunotherapy, in particular, is closely related to tumor immune microenvironment. This review searched for high-quality literature included within PubMed, Web of Science, and Scopus using the keywords "head and neck cancers," "tumor microenvironment" and "immunotherapy," with the view to summarizing the characteristics of HNSCC immune microenvironment and how various subsets of immune cells promote tumorigenesis. At the same time, based on the favorable prospects of immunotherapy having been shown currently, the study is committed to pinpointing the latest progress of HNSCC immunotherapy, which is of great significance in not only further guiding the diagnosis and treatment of HNSCC, but also conducting its prognostic judgement.

Generation of murine tumor models refractory to αPD-1/-L1 therapies due to defects in antigen processing/presentation or IFNγ signaling using CRISPR/Cas9

Immune checkpoint blockade (ICB) targeting the programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1) fails to provide clinical benefit for most cancer patients due to primary or acquired resistance. Drivers of ICB resistance include tumor antigen processing/presentation machinery (APM) and IFNγ signaling mutations. Thus, there is an unmet clinical need to develop alternative therapies for these patients. To this end, we have developed a CRISPR/Cas9 approach to generate murine tumor models refractory to PD-1/-L1 inhibition due to APM/IFNγ signaling mutations. Guide RNAs were employed to delete B2m, Jak1, or Psmb9 genes in ICB-responsive EMT6 murine tumor cells. B2m was deleted in ICB-responsive MC38 murine colon cancer cells. We report a detailed development and validation workflow including whole exome and Sanger sequencing, western blotting, and flow cytometry to assess target gene deletion. Tumor response to ICB and immune effects of gene deletion were assessed in syngeneic mice. This workflow can help accelerate the discovery and development of alternative therapies and a deeper understanding of the immune consequences of tumor mutations, with potential clinical implications.

Patient-derived Immunocompetent Tumor Organoids: A Platform for Chemotherapy Evaluation in the Context of T-cell Recognition

Most of the anticancer compounds synthesized by chemists are primarily evaluated for their direct cytotoxic effects at the cellular level, often overlooking the critical role of the immune system. In this study, we developed a patient-derived, T-cell-retaining tumor organoid model that allows us to evaluate the anticancer efficacy of chemical drugs under the synergistic paradigm of antigen-specific T-cell-dependent killing, which may reveal the missed drug hits in the simple cytotoxic assay. We evaluated clinically approved platinum (Pt) drugs and a custom library of twenty-eight PtIV compounds. We observed low direct cytotoxicity of Pt drugs, but variable synergistic effects in combination with immune checkpoint inhibitors (ICIs). In contrast, the majority of PtIV compounds exhibited potent tumor-killing capabilities. Interestingly, several PtIV compounds went beyond direct tumor killing and showed significant immunosynergistic effects with ICIs, outstanding at sub-micromolar concentrations. Among these, Pt-19, PtIV compounds with cinnamate axial ligands, emerged as the most therapeutically potent, demonstrating pronounced immunosynergistic effects by promoting the release of cytotoxic cytokines, activating immune-related pathways and enhancing T cell receptor (TCR) clonal expansion. Overall, this initiative marks the first use of patient-derived immunocompetent tumor organoids to explore and study chemotherapy, advancing their path toward more effective small molecule drug discovery.

Tumor histoculture captures the dynamic interactions between tumor and immune components in response to anti-PD1 in head and neck cancer

Dynamic interactions within the tumor micro-environment drive patient response to immune checkpoint inhibitors. Existing preclinical models lack true representation of this complexity. Using a Head and Neck cancer patient derived TruTumor histoculture platform, the response spectrum of 70 patients to anti-PD1 treatment is investigated in this study. With a subset of 55 patient samples, multiple assays to characterize T-cell reinvigoration and tumor cytotoxicity are performed. Based on levels of these two response parameters, patients are stratified into five sub-cohorts, with the best responder and non-responder sub-cohorts falling at extreme ends of the spectrum. The responder sub-cohort exhibits high T-cell reinvigoration, high tumor cytotoxicity with T-cells homing into the tumor upon treatment whereas immune suppression and tumor progression pathways are pre-dominant in the non-responders. Some moderate responders benefit from combination of anti-CTLA4 with anti-PD1, which is evident from better cytotoxic T-cell: T-regulatory cell ratio and enhancement of tumor cytotoxicity. Baseline and on-treatment gene expression signatures from this study stratify responders and non-responders in unrelated clinical datasets.

Extracellular Vesicles, Circulating Tumor Cells, and Immune Checkpoint Inhibitors: Hints and Promises

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of cancer, in particular lung cancer, while the introduction of predictive biomarkers from liquid biopsies has emerged as a promising tool to achieve an effective and personalized therapy response. Important progress has also been made in the molecular characterization of extracellular vesicles (EVs) and circulating tumor cells (CTCs), highlighting their tremendous potential in modulating the tumor microenvironment, acting on immunomodulatory pathways, and setting up the pre-metastatic niche. Surface antigens on EVs and CTCs have proved to be particularly useful in the case of the characterization of potential immune escape mechanisms through the expression of immunosuppressive ligands or the transport of cargos that may mitigate the antitumor immune function. On the other hand, novel approaches, to increase the expression of immunostimulatory molecules or cargo contents that can enhance the immune response, offer premium options in combinatorial clinical strategies for precision immunotherapy. In this review, we discuss recent advances in the identification of immune checkpoints using EVs and CTCs, their potential applications as predictive biomarkers for ICI therapy, and their prospective use as innovative clinical tools, considering that CTCs have already been approved by the Food and Drug Administration (FDA) for clinical use, but providing good reasons to intensify the research on both.

Unveiling the mechanisms and challenges of cancer drug resistance

Cancer treatment faces many hurdles and resistance is one among them. Anti-cancer treatment strategies are evolving due to innate and acquired resistance capacity, governed by genetic, epigenetic, proteomic, metabolic, or microenvironmental cues that ultimately enable selected cancer cells to survive and progress under unfavorable conditions. Although the mechanism of drug resistance is being widely studied to generate new target-based drugs with better potency than existing ones. However, due to the broader flexibility in acquired drug resistance, advanced therapeutic options with better efficacy need to be explored. Combination therapy is an alternative with a better success rate though the risk of amplified side effects is commonplace. Moreover, recent groundbreaking precision immune therapy is one of the ways to overcome drug resistance and has revolutionized anticancer therapy to a greater extent with the only limitation of being individual-specific and needs further attention. This review will focus on the challenges and strategies opted by cancer cells to withstand the current therapies at the molecular level and also highlights the emerging therapeutic options -like immunological, and stem cell-based options that may prove to have better potential to challenge the existing problem of therapy resistance. Video Abstract.

The dynamic role of immune checkpoint molecules in diagnosis, prognosis, and treatment of head and neck cancers

Head and neck cancer (HNC) is the sixth most common cancer type, accounting for approximately 277,597 deaths worldwide. Recently, the Food and Drug Administration (FDA) has approved immune checkpoint blockade (ICB) agents targeting programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) as a treatment regimen for head and neck squamous cell carcinomas (HNSCC). Studies have reported the role of immune checkpoint inhibitors as targeted therapeutic regimens that unleash the immune response against HNSCC tumors. However, the overall response rates to immunotherapy vary between 14-32% in recurrent or metastatic HNSCC, with clinical response and treatment success being unpredictable. Keeping this perspective in mind, it is imperative to understand the role of T cells, natural killer cells, and antigen-presenting cells in modulating the immune response to immunotherapy. In lieu of this, these immune molecules could serve as prognostic and predictive biomarkers to facilitate longitudinal monitoring and understanding of treatment dynamics. These immune biomarkers could pave the path for personalized monitoring and management of HNSCC. In this review, we aim to provide updated immunological insight on the mechanism of action, expression, and the clinical application of immune cells' stimulatory and inhibitory molecules as prognostic and predictive biomarkers in HNC. The review is focused mainly on CD27 and CD137 (members of the TNF-receptor superfamily), natural killer group 2 member D (NKG2D), tumor necrosis factor receptor superfamily member 4 (TNFRSF4 or OX40), S100 proteins, PD-1, PD-L1, PD-L2, T cell immunoglobulin and mucin domain 3 (TIM-3), cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), lymphocyte-activation gene 3 (LAG-3), indoleamine-pyrrole 2,3-dioxygenase (IDO), B and T lymphocyte attenuator (BTLA). It also highlights the importance of T, natural killer, and antigen-presenting cells as robust biomarker tools for understanding immune checkpoint inhibitor-based treatment dynamics. Though a comprehensive review, all aspects of the immune molecules could not be covered as they were beyond the scope of the review; Further review articles can cover other aspects to bridge the knowledge gap.

Autophagy-modulating biomembrane nanostructures: A robust anticancer weapon by modulating the inner and outer cancer environment

Recently, biomembrane nanostructures, such as liposomes, cell membrane-coated nanostructures, and exosomes, have demonstrated promising anticancer therapeutic effects. These nanostructures possess remarkable biocompatibility, multifunctionality, and low toxicity. However, their therapeutic efficacy is impeded by chemoresistance and radiotherapy resistance, which are closely associated with autophagy. Modulating autophagy could enhance the therapeutic sensitivity and effectiveness of these biomembrane nanostructures by influencing the immune system and the cancer microenvironment. For instance, autophagy can regulate the immunogenic cell death of cancer cells, antigen presentation of dendritic cells, and macrophage polarization, thereby activating the inflammatory response in the cancer microenvironment. Furthermore, combining autophagy-regulating drugs or genes with biomembrane nanostructures can exploit the targeting and long-term circulation properties of these nanostructures, leading to increased drug accumulation in cancer cells. This review explores the role of autophagy in carcinogenesis, cancer progression, metastasis, cancer immune responses, and resistance to treatment. Additionally, it highlights recent research advancements in the synergistic anticancer effects achieved through autophagy regulation by biomembrane nanostructures. The review also discusses the prospects and challenges associated with the future clinical translation of these innovative treatment strategies. In summary, these findings provide valuable insights into autophagy, autophagy-modulating biomembrane-based nanostructures, and the underlying molecular mechanisms, thereby facilitating the development of promising cancer therapeutics.

Phytochemicals in regulating PD-1/PD-L1 and immune checkpoint blockade therapy

Clinical treatment and preclinical studies have highlighted the role of immune checkpoint blockade in cancer treatment. Research has been devoted to developing immune checkpoint inhibitors in combination with other drugs to achieve better efficacy or reduce adverse effects. Phytochemicals sourced from vegetables and fruits have demonstrated antiproliferative, proapoptotic, anti-migratory, and antiangiogenic effects against several cancers. Phytochemicals also modulate the tumor microenvironment such as T cells, regulatory T cells, and cytokines. Recently, several phytochemicals have been reported to modulate immune checkpoint proteins in in vivo or in vitro models. Phytochemicals decreased programmed cell death ligand-1 expression and synergized programmed cell death receptor 1 (PD-1) monoclonal antibody to suppress tumor growth. Combined administration of phytochemicals and PD-1 monoclonal antibody enhanced the tumor growth inhibition as well as CD4+ /CD8+ T-cell infiltration. In this review, we discuss immune checkpoint molecules as potential therapeutic targets of cancers. We further assess the impact of phytochemicals including carotenoids, polyphenols, saponins, and organosulfur compounds on cancer PD-1/programmed cell death ligand-1 immune checkpoint molecules and document their combination effects with immune checkpoint inhibitors on various malignancies.

Unraveling T cell exhaustion in the immune microenvironment of osteosarcoma via single-cell RNA transcriptome

Osteosarcoma (OS) represents a profoundly invasive malignancy of the skeletal system. T cell exhaustion (Tex) is known to facilitate immunosuppression and tumor progression, but its role in OS remains unclear. In this study, single-cell RNA sequencing data was employed to identify exhausted T cells within the tumor immune microenvironment (TIME) of OS. We found that exhausted T cells exhibited substantial infiltration in OS samples. Pseudotime trajectory analysis revealed a progressive increase in the expression of various Tex marker genes, including PDCD1, CTLA4, LAG3, ENTPD1, and HAVCR2 in OS. GSVA showed that apoptosis, fatty acid metabolism, xenobiotic metabolism, and the interferon pathway were significantly activated in exhausted T cells in OS. Subsequently, a prognostic model was constructed using two Tex-specific genes, MYC and FCGR2B, which exhibited exceptional prognostic accuracy in two independent cohorts. Drug sensitivity analysis revealed that OS patients with a low Tex risk were responsive to Dasatinib and Pazopanib. Finally, immunohistochemistry verified that MYC and FCGR2B were significantly upregulated in OS tissues compared with adjacent tissues. This study investigates the role of Tex within the TIME of OS, and offers novel insights into the mechanisms underlying disease progression as well as the potential treatment strategies for OS.

Plasmid co-expressing siRNA-PD-1 and Endostatin carried by attenuated Salmonella enhanced the anti-melanoma effect via inhibiting the expression of PD-1 and VEGF on tumor-bearing mice

Melanoma, the most perilous form of skin cancer, is known for its inherent resistance to chemotherapy. Even with advances in tumor immunotherapy, the survival of patients with advanced or recurrent melanomas remains poor. Over time, melanoma tumor cells may produce excessive angiogenic factors, necessitating the use of combinations of angiogenesis inhibitors, including broad-spectrum options, to combat melanoma. Among these inhibitors, Endostatin is one of the most broad-spectrum and least toxic angiogenesis inhibitors. We found Endostatin significantly increased the infiltration of CD8+ T cells and reduced the infiltration of M2 tumor-associated macrophages (TAMs) in the melanoma tumor microenvironment (TME). Interestingly, we also observed high expression levels of programmed death 1 (PD-1), an essential immune checkpoint molecule associated with tumor immune evasion, within the melanoma tumor microenvironment despite the use of Endostatin. To address this issue, we investigated the effects of a plasmid expressing Endostatin and PD-1 siRNA, wherein Endostatin was overexpressed while RNA interference (RNAi) targeted PD-1. These therapeutic agents were delivered using attenuated Salmonella in melanoma-bearing mice. Our results demonstrate that pEndostatin-siRNA-PD-1 therapy exhibits optimal therapeutic efficacy against melanoma. We found that pEndostatin-siRNA-PD-1 therapy promotes the infiltration of CD8+ T cells and the expression of granzyme B in melanoma tumors. Importantly, combined inhibition of angiogenesis and PD-1 significantly suppresses melanoma tumor progression compared with the inhibition of angiogenesis or PD-1 alone. Based on these findings, our study suggests that combining PD-1 inhibition with angiogenesis inhibitors holds promise as a clinical strategy for the treatment of melanoma.

A new era in cancer treatment: harnessing ZIF-8 nanoparticles for PD-1 inhibitor delivery

This review delves into the potential of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles in augmenting the efficacy of cancer immunotherapy, with a special focus on the delivery of programmed cell death receptor 1 (PD-1) inhibitors. The multifunctional nature of ZIF-8 nanoparticles as drug carriers is emphasized, with their ability to encapsulate a range of therapeutic agents, including PD-1 inhibitors, and facilitate their targeted delivery to tumor locations. By manipulating the pore size and surface characteristics of ZIF-8 nanoparticles, controlled drug release can be realized. The strategic use of ZIF-8 nanoparticles to deliver PD-1 inhibitors presents a precise and targeted modality for cancer treatment, reducing off-target impacts and enhancing therapeutic effectiveness. This combined strategy addresses the existing challenges and constraints of current immunotherapy techniques, with the ultimate goal of enhancing patient outcomes in cancer therapy.

Pyroptosis: a double-edged sword in lung cancer and other respiratory diseases

Pyroptosis is an active cell death process mediated by gasdermin family proteins including Gasdermin A (GSDMA), Gasdermin B (GSDMB), Gasdermin C (GSDMC), Gasdermin D (GSDMD), Gasdermin E (GSDME, DFNA5), and DFNB59. Emerging evidences have shown that pyroptosis contributes to many pulmonary diseases, especially lung cancer, and pneumonia. The exact roles of pyroptosis and gasdermin family proteins are tremendously intricate. Besides, there are evidences that pyroptosis contributes to these respiratory diseases. However, it often plays a dual role in these diseases which is a cause for concern and makes it difficult for clinical translation. This review will focus on the multifaceted roles of pyroptosis in respiratory diseases.

NAD+ Metabolism-Related Gene Profile Can Be a Relevant Source of Squamous Cell Carcinoma Biomarkers

Poor survival rates of squamous cell carcinomas (SCCs) are associated with high recurrence, metastasis, and late diagnosis, due in part to a limited number of reliable biomarkers. Thus, the identification of signatures improving the diagnosis of different SCC types is mandatory. Considering the relevant role of NAD+ metabolism in SCC chemoprevention and therapy, the study aimed at identifying new biomarkers based on NAD+ metabolism-related gene (NMRG) expression. Gene expression of 18 NMRGs and clinical-pathological information for patients with head and neck SCC (HNSCC), lung SCC (LuSCC), and cervix SCC (CeSCC) from The Cancer Genome Atlas (TCGA) were analyzed by several bioinformatic tools. We identified a 16-NMRG profile discriminating 3 SCCs from 3 non-correlated tumors. We found several genes for HNSCC, LuSCC, and CeSCC with high diagnostic power. Notably, three NMRGs were SCC-type specific biomarkers. Furthermore, specific signatures displayed high diagnostic power for several clinical-pathological characteristics. Analyzing tumor-infiltrating immune cell profiles and PD-1/PD-L1 levels, we found that NMRG expression was associated with suppressive immune microenvironment mainly in HNSCC. Finally, the evaluation of patient survival identified specific genes for HNSCC, LuSCC, and CeSCC with potential prognostic power. Therefore, our analyses indicate NAD+ metabolism as an important source of SCC biomarkers and potential therapeutic targets.

Enhancing immune responses of ESC-based TAA cancer vaccines with a novel OMV delivery system

Embryonic stem cell (ESC)-derived epitopes can act as therapeutic tumor vaccines against different types of tumors Jin (Adv Healthc Mater 2023). However, these epitopes have poor immunogenicity and stimulate insufficient CD8+ T cell responses, which motivated us to develop a new method to deliver and enhance their effectiveness. Bacterial outer membrane vesicles (OMVs) can serve as immunoadjuvants and act as a delivery vector for tumor antigens. In the current study, we engineered a new OMV platform for the co-delivery of ESC-derived tumor antigens and immune checkpoint inhibitors (PD-L1 antibody). An engineered Staphylococcal Protein A (SpA) was created to non-specifically bind to anti-PD-L1 antibody. SpyCatcher (SpC) and SpA were fused into the cell outer membrane protein OmpA to capture SpyTag-attached peptides and PD-L1 antibody, respectively. The modified OMV was able to efficiently conjugate with ESC-derived TAAs and PD-L1 antibody (SpC-OMVs + SpT-peptides + anti-PD-L1), increasing the residence time of TAAs in the body. The results showed that the combination therapy of ESC-based TAAs and PD-L1 antibody delivered by OMV had significant inhibitory effects in mouse tumor model. Specifically, it was effective in reducing tumor growth by enhancing IFN-γ-CD8+ T cell responses and increasing the number of CD8+ memory cells and antigen-specific T cells. Overall, the new OMV delivery system is a versatile platform that can enhance the immune responses of ESC-based TAA cancer vaccines.

DCLK1 and its oncogenic functions: A promising therapeutic target for cancers

Doublecortin-like kinase 1 (DCLK1), a significant constituent of the protein kinase superfamily and the doublecortin family, has been recognized as a prooncogenic factor that exhibits a strong association with the malignant progression and clinical prognosis of various cancers. DCLK1 serves as a stem cell marker that governs tumorigenesis, tumor cell reprogramming, and epithelial-mesenchymal transition. Multiple studies have indicated the capable of DCLK1 in regulating the DNA damage response and facilitating DNA damage repair. Additionally, DCLK1 is involved in the regulation of the immune microenvironment and the promotion of tumor immune evasion. Recently, DCLK1 has emerged as a promising therapeutic target for a multitude of cancers. Several small-molecule inhibitors of DCLK1 have been identified. Nevertheless, the biological roles of DCLK1 are mainly ambiguous, particularly with the disparities between its α- and β-form transcripts in the malignant progression of cancers, which impedes the development of more precisely targeted drugs. This article focuses on tumor stem cells, tumor epithelial-mesenchymal transition, the DNA damage response, and the tumor microenvironment to provide a comprehensive overview of the association between DCLK1 and tumor malignant progression, address unsolved questions and current challenges, and project future directions for targeting DCLK1 for the diagnosis and treatment of cancers.

Early T Cell Infiltration Correlates with Anti-CTLA4 Treatment Response in Murine Cancer Models

Immune checkpoint inhibitor (ICI) Abs are a revolutionary class of cancer treatment, but only ∼30% of patients receive a lasting benefit from therapy. Preclinical studies using animals from the same genetic backgrounds, challenged with the same cancer models, also show nonuniform responses. Most mouse studies that have evaluated tumor-infiltrating leukocytes after ICI therapy cannot directly correlate their findings with treatment outcomes, because terminal methods were used to acquire immune infiltrate data. In the present study, we used fine-needle aspiration (a nonterminal sampling method) to collect multiple aspirates over several days from s.c. implanted P815, CT26, and 4T1 mouse cancer models treated with ICI Abs. These aspirates were then analyzed with flow cytometry to directly correlate tumor-infiltrating leukocyte populations with treatment success. We found that the P815 and CT26 models respond well to anti-CTLA4 therapies. Among P815-challenged animals, mice that regressed following anti-CTLA4 treatment showed significant increases in CD8+ T cells on days 3, 5, and 7 and in CD4+ T cells on days 5 and 7 and a decrease in macrophages and monocytes on days 3, 5, and 7 after treatment. Similar results were obtained in the CT26 model on day 11 posttreatment. Our study is the first, to our knowledge, to directly correlate early tumor infiltration of T cells with anti-CTLA4 treatment success, thus providing a mechanistic clue toward understanding why alloidentical mice challenged with identical tumors do not respond uniformly to ICI therapies.

The role of immune checkpoints in antitumor response: a potential antitumor immunotherapy

Immunotherapy aims to stimulate the immune system to inhibit tumor growth or prevent metastases. Tumor cells primarily employ altered expression of human leukocyte antigen (HLA) as a mechanism to avoid immune recognition and antitumor immune response. The antitumor immune response is primarily mediated by CD8+ cytotoxic T cells (CTLs) and natural killer (NK) cells, which plays a key role in the overall anti-tumor immune response. It is crucial to comprehend the molecular events occurring during the activation and subsequent regulation of these cell populations. The interaction between antigenic peptides presented on HLA-I molecules and the T-cell receptor (TCR) constitutes the initial signal required for T cell activation. Once activated, in physiologic circumstances, immune checkpoint expression by T cells suppress T cell effector functions when the antigen is removed, to ensures the maintenance of self-tolerance, immune homeostasis, and prevention of autoimmunity. However, in cancer, the overexpression of these molecules represents a common method through which tumor cells evade immune surveillance. Numerous therapeutic antibodies have been developed to inhibit immune checkpoints, demonstrating antitumor activity with fewer side effects compared to traditional chemotherapy. Nevertheless, it's worth noting that many immune checkpoint expressions occur after T cell activation and consequently, altered HLA expression on tumor cells could diminish the clinical efficacy of these antibodies. This review provides an in-depth exploration of immune checkpoint molecules, their corresponding blocking antibodies, and their clinical applications.