Exploiting innate immunity for cancer immunotherapy

SMARCA4 mutation induces tumor cell-intrinsic defects in enhancer landscape and resistance to immunotherapy

Cancer genomic studies have identified frequent alterations in components of the SWI/SNF (SWItch/Sucrose Non- Fermenting) chromatin remodeling complex including SMARCA4 and ARID1A . Importantly, clinical reports indicate that SMARCA4 -mutant lung cancers respond poorly to immunotherapy and have dismal prognosis. However, the mechanistic basis of immunotherapy resistance is unknown. Here, we corroborated the clinical findings by using immune-humanized, syngeneic, and genetically engineered mouse models of lung cancer harboring SMARCA4 deficiency. Specifically, we show that SMARCA4 loss caused decreased response to anti-PD1 immunotherapy associated with significantly reduced infiltration of dendritic cells (DCs) and CD4+ T cells into the tumor microenvironment (TME). Mechanistically, we show that SMARCA4 loss in tumor cells led to profound downregulation of STING, IL1β and other components of the innate immune system as well as inflammatory cytokines that are required for efficient recruitment and activity of immune cells. We establish that this deregulation of gene expression is caused by cancer cell-intrinsic reprogramming of the enhancer landscape with marked loss of chromatin accessibility at enhancers of genes involved in innate immune response such as STING, IL1β, type I IFN and inflammatory cytokines. Interestingly, we observed that transcription factor NF-κB binding motif was highly enriched in enhancers that lose accessibility upon SMARCA4 deficiency. Finally, we confirmed that SMARCA4 and NF-κB co-occupy the same genomic loci on enhancers associated with STING and IL1β, indicating a functional interplay between SMARCA4 and NF-κB. Taken together, our findings provide the mechanistic basis for the poor response of SMARCA4 -mutant tumors to anti-PD1 immunotherapy and establish a functional link between SMARCA4 and NF-κB on innate immune and inflammatory gene expression regulation.

Hallmarks of cancer resistance

This review explores the hallmarks of cancer resistance, including drug efflux mediated by ATP-binding cassette (ABC) transporters, metabolic reprogramming characterized by the Warburg effect, and the dynamic interplay between cancer cells and mitochondria. The role of cancer stem cells (CSCs) in treatment resistance and the regulatory influence of non-coding RNAs, such as long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are studied. The chapter emphasizes future directions, encompassing advancements in immunotherapy, strategies to counter adaptive resistance, integration of artificial intelligence for predictive modeling, and the identification of biomarkers for personalized treatment. The comprehensive exploration of these hallmarks provides a foundation for innovative therapeutic approaches, aiming to navigate the complex landscape of cancer resistance and enhance patient outcomes.

The relationship between innate/adaptive immunity and gastrointestinal cancer : a multi-omics Mendelian randomization study

BACKGROUND

Innate/adaptive immunity is the key to anti-tumor therapy. However, its causal relationship to Gastrointestinal (GI) cancer remains unclear.

METHODS

Immunity genes were extracted from the MSigDB database. The Genome-wide association studies (GWAS) summary data of GI cancer were integrated with expression quantitative trait loci (eQTL) and DNA methylation quantitative trait loci (mQTL) associated with genes. Summary-data-based Mendelian randomization (SMR) and co-localization analysis were used to reveal causal relationships between genes and GI cancer. Two-sample MR analysis was used for sensitivity analysis. Single cell analysis clarified the enrichment of genes.

RESULTS

Three-step SMR analysis showed that a putative mechanism, cg17294865 CpG site regulating HLA-DRA expression was negatively associated with gastric cancer risk. HLA-DRA was significantly differentially expressed in monocyte/macrophage and myeloid cells in gastric cancer.

CONCLUSION

This study provides evidence that upregulating the expression level of HLA-DRA can reduce the risk of gastric cancer.

Non-viral vector-based genome editing for cancer immunotherapy

Despite the exciting promise of cancer immunotherapy in the clinic, immune checkpoint blockade therapy and T cell-based therapies are often associated with low response rates, intrinsic and adaptive immune resistance, and systemic side effects. CRISPR-Cas-based genome editing appears to be an effective strategy to overcome these unmet clinical needs. As a safer delivery platform for the CRISPR-Cas system, non-viral nanoformulations have been recently explored to target tumor cells and immune cells, aiming to improve cancer immunotherapy on a gene level. In this review, we summarized the efforts of non-viral vector-based CRISPR-Cas-mediated genome editing in tumor cells and immune cells for cancer immunotherapy. Their design rationale and specific applications were highlighted.

Beyond success: unveiling the hidden potential of radiotherapy and immunotherapy in solid tumors

Immunotherapy, particularly with immune checkpoint inhibitors, has significantly transformed cancer treatment. Despite its success, many patients struggle to respond adequately or sustain long-lasting clinical improvement. A growing consensus has emerged that radiotherapy (RT) enhances the response rate and overall efficacy of immunotherapy. Although combining RT and immunotherapy has been extensively investigated in preclinical models and has shown promising results, establishing itself as a dynamic and thriving area of research, clinical evidence for this combination strategy over the past five years has shown both positive and disappointing results, suggesting the need for a more nuanced understanding. This review provides a balanced and updated analysis of the combination of immunotherapy and RT. We summarized the preclinical mechanisms through which RT boosts antitumor immune responses and mainly focused on the outcomes of recently updated clinical trials, including those that may not have met expectations. We investigated the optimization of the therapeutic potential of this combined strategy, including key challenges, such as fractionation and scheduling, lymph node irradiation, and toxicity. Finally, we offered insights into the prospects and challenges associated with the clinical translation of this combination therapy, providing a realistic perspective on the current state of research and potential future directions.

Genetic Evidence for a Causal Relationship Between Innate Leukocytes and the Risk of Digestive System Cancers in East Asians and Europeans

Background

Peripheral traditional immune cell disorder plays an important role in cancer onset and development. The causal relationships between leukocytes prior to cancer and the risk of digestive system cancer remain unknown. This study assesses the causal correlations between leukocytes and digestive system cancer risk in East Asians and Europeans.

Methods

Summary-level data on leukocyte-related genetic variation were extracted from Biobank Japan (107,964 participants) and a recent large-scale meta-analysis (563,946 participants). Summary-level data for the cancers were obtained from Biobank Japan (212,978 individuals) and the FinnGen consortium (178,802 participants). Univariable and multivariable Mendelian randomization (MR) analyses were performed on East Asians and Europeans separately.

Results

Univariable MR analysis demonstrated the significant association between circulating eosinophil counts and risk of colorectal cancer (CRC) in East Asians (odds ratio (OR) = 0.80, 95% confidence interval (CI): 0.69 - 0.92, P = 0.002) and a suggestive relationship in the European population (OR = 0.86, 95% CI: 0.77 - 0.97, P = 0.013). An inverse suggestive association was observed between levels of basophils and the risk of gastric cancer (GC) in East Asians (OR = 0.83, 95% CI: 0.72 - 0.97, P = 0.019). The multivariable MR analysis showed the independent causal effect of eosinophil count on CRC risk in East Asians (OR = 0.72, 95% CI: 0.57 - 0.92, P = 0.009) and Europeans (OR = 0.80, 95% CI: 0.70 - 0.92, P = 0.002). Circulating basophils served as the negative causal factor in GC risk in East Asians (OR = 0.80, 95% CI: 0.67 - 0.94, P = 0.007).

Conclusions

Our MR analyses revealed a genetic causal relationship between reduced blood eosinophils and an increased CRC risk in both Europeans and East Asians. Furthermore, our results suggested a causal association between decreased basophils and an elevated GC risk specifically in East Asians.

Autophagy in cancer immunotherapy: Perspective on immune evasion and cell death interactions

Both the innate and adaptive immune systems work together to produce immunity. Cancer immunotherapy is a novel approach to tumor suppression that has arisen in response to the ineffectiveness of traditional treatments like radiation and chemotherapy. On the other hand, immune evasion can diminish immunotherapy's efficacy. There has been a lot of focus in recent years on autophagy and other underlying mechanisms that impact the possibility of cancer immunotherapy. The primary feature of autophagy is the synthesis of autophagosomes, which engulf cytoplasmic components and destroy them by lysosomal degradation. The planned cell death mechanism known as autophagy can have opposite effects on carcinogenesis, either increasing or decreasing it. It is autophagy's job to maintain the balance and proper functioning of immune cells like B cells, T cells, and others. In addition, autophagy controls whether macrophages adopt the immunomodulatory M1 or M2 phenotype. The ability of autophagy to control the innate and adaptive immune systems is noteworthy. Interleukins and chemokines are immunological checkpoint chemicals that autophagy regulates. Reducing antigen presentation to induce immunological tolerance is another mechanism by which autophagy promotes cancer survival. Therefore, targeting autophagy is of importance for enhancing potential of cancer immunotherapy.

Mechanisms of myeloid-derived suppressor cell-mediated immunosuppression in colorectal cancer and related therapies

Severe immunosuppression is a hallmark of colorectal cancer (CRC). Myeloid-derived suppressor cells (MDSCs), one of the most abundant components of the tumor stroma, play an important role in the invasion, metastasis, and immune escape of CRC. MDSCs create an immunosuppressive microenvironment by inhibiting the proliferation and activation of immunoreactive cells, including T and natural killer cells, as well as by inducing the proliferation of immunosuppressive cells, such as regulatory T cells and tumor-associated macrophages, which, in turn, promote the growth of cancer cells. Thus, MDSCs are key contributors to the emergence of an immunosuppressive microenvironment in CRC and play an important role in the breakdown of antitumor immunity. In this narrative review, we explore the mechanisms through which MDSCs contribute to the immunosuppressive microenvironment, the current therapeutic approaches and technologies targeting MDSCs, and the therapeutic potential of modulating MDSCs in CRC treatment. This study provides ideas and methods to enhance survival rates in patients with CRC.

Exploring the Immunological Profile in Breast Cancer: Recent Advances in Diagnosis and Prognosis through Circulating Tumor Cells

This review offers a comprehensive exploration of the intricate immunological landscape of breast cancer (BC), focusing on recent advances in diagnosis and prognosis through the analysis of circulating tumor cells (CTCs). Positioned within the broader context of BC research, it underscores the pivotal role of the immune system in shaping the disease's progression. The primary objective of this investigation is to synthesize current knowledge on the immunological aspects of BC, with a particular emphasis on the diagnostic and prognostic potential offered by CTCs. This review adopts a thorough examination of the relevant literature, incorporating recent breakthroughs in the field. The methodology section succinctly outlines the approach, with a specific focus on CTC analysis and its implications for BC diagnosis and prognosis. Through this review, insights into the dynamic interplay between the immune system and BC are highlighted, with a specific emphasis on the role of CTCs in advancing diagnostic methodologies and refining prognostic assessments. Furthermore, this review presents objective and substantiated results, contributing to a deeper understanding of the immunological complexity in BC. In conclusion, this investigation underscores the significance of exploring the immunological profile of BC patients, providing valuable insights into novel advances in diagnosis and prognosis through the utilization of CTCs. The objective presentation of findings emphasizes the crucial role of the immune system in BC dynamics, thereby opening avenues for enhanced clinical management strategies.

Exploration of signature based on T cell-related genes in stomach adenocarcinoma by analysis of single cell sequencing data

BACKGROUND

Gastric cancer (GC) is a leading reason for the death of cancer around the world. The immune microenvironment counts a great deal in immunotherapy of advanced tumors, in which T cells exert an indispensable function.

METHODS

Single-cell RNA sequencing data were utilized to characterize the expression profile of T cells, followed by T cell-related genes (TCRGs) to construct signature and measure differences in survival time, enrichment pathways, somatic mutation status, immune status, and immunotherapy between groups.

RESULTS

The complex tumor microenvironment was analyzed by scRNA-seq data of GC patients. We screened for these T cell signature expression genes and the TCRGs-based signature was successfully constructed and relied on the riskscore grouping. In gene set enrichment analysis, it was shown that pro-tumor and suppressive immune pathways were more abundant in the higher risk group. We also found different infiltration of immune cells in two groups, and that the higher risk samples had a poorer response to immunotherapy.

CONCLUSION

Our study established a prognostic model, in which different groups had different prognosis, immune status, and enriched features. These results have provided additional insights into prognostic evaluation and the development of highly potent immunotherapies in GC.

Targeting two radiation-induced immunosuppressive pathways to improve the efficacy of normofractionated radiation therapy in a preclinical colorectal cancer model

PURPOSE

We have previously demonstrated in a murine colorectal cancer model that normofractionated RT (normoRT: 18 × 2 Gy) induced MDSC infiltration and PD-L1 expression, while hypofractionated RT (hypoRT: 3 × 8 Gy) induced Treg. Here, we wanted to assess whether the association of normoRT with treatments that target two radiation-induced immunosuppressive pathways (MDSC and PD-L1) could improve tumor control.

MATERIALS AND METHODS

Subcutaneous tumors were induced using colon tumor cells (CT26) in immunocompetent mice (BALB/c) and were treated with RT alone (18 × 2 Gy or 3 × 8 Gy), or concomitantly with 5-Fluorouracil (5FU) (10 mg/kg) to deplete MDSC, and/or anti-PD-L1 (10 mg/kg). We assessed the impact of these combinations on tumor growth and immune cells infiltration by flow cytometry. In addition, we performed tumor rechallenge experiments and IFN-γ ELISpots to study the long-term memory response.

RESULTS

Even though tumor growth was significantly delayed in the RT + 5FU compared to 5FU and untreated groups (p < .05), there was no significant difference between RT + 5FU (CRT) and RT alone. The rate of MDSC increased significantly 1 week after the end of normoRT (8.09% ± 1.03%, p < .05) and decreased with the addition of 5FU (3.39% ± 0.69%, p < .05). PD-L1 expressing tumor cells were increased after treatment. Adding anti-PD-L1 significantly delayed tumor growth, achieved the highest complete response rate, and induced a long-lasting protective specific anti-tumor immunity.

CONCLUSIONS

These results tend to demonstrate the interest of inhibiting two radiation-induced immunosuppressive mechanisms. In patients, the combination of normoRT with 5FU is already the standard of care in locally advanced rectal cancer. Adding an anti-PD-L1 to this treatment could show promising results.

The enhanced antitumor activity of bispecific antibody targeting PD-1/PD-L1 signaling

The programmed cell death 1 (PD-1) signaling pathway, a key player in immune checkpoint regulation, has become a focal point in cancer immunotherapy. In the context of cancer, upregulated PD-L1 on tumor cells can result in T cell exhaustion and immune evasion, fostering tumor progression. The advent of PD-1/PD-L1 inhibitor has demonstrated clinical success by unleashing T cells from exhaustion. Nevertheless, challenges such as resistance and adverse effects have spurred the exploration of innovative strategies, with bispecific antibodies (BsAbs) emerging as a promising frontier. BsAbs offer a multifaceted approach to cancer immunotherapy by simultaneously targeting PD-L1 and other immune regulatory molecules. We focus on recent advancements in PD-1/PD-L1 therapy with a particular emphasis on the development and potential of BsAbs, especially in the context of solid tumors. Various BsAb products targeting PD-1 signaling are discussed, highlighting their unique mechanisms of action and therapeutic potential. Noteworthy examples include anti-TGFβ × PD-L1, anti-CD47 × PD-L1, anti-VEGF × PD-L1, anti-4-1BB × PD-L1, anti-LAG-3 × PD-L1, and anti-PD-1 × CTLA-4 BsAbs. Besides, we summarize ongoing clinical studies evaluating the efficacy and safety of these innovative BsAb agents. By unraveling the intricacies of the tumor microenvironment and harnessing the synergistic effects of anti-PD-1/PD-L1 BsAbs, there exists the potential to elevate the precision and efficacy of cancer immunotherapy, ultimately enabling the development of personalized treatment strategies tailored to individual patient profiles.

CAR-NK cells for cancer immunotherapy: recent advances and future directions

Natural Killer (NK) cells, intrinsic to the innate immune system, are pivotal in combating cancer due to their independent cytotoxic capabilities in antitumor immune response. Unlike predominant treatments that target T cell immunity, the limited success of T cell immunotherapy emphasizes the urgency for innovative approaches, with a spotlight on harnessing the potential of NK cells. Despite tumors adapting mechanisms to evade NK cell-induced cytotoxicity, there is optimism surrounding Chimeric Antigen Receptor (CAR) NK cells. This comprehensive review delves into the foundational features and recent breakthroughs in comprehending the dynamics of NK cells within the tumor microenvironment. It critically evaluates the potential applications and challenges associated with emerging CAR-NK cell therapeutic strategies, positioning them as promising tools in the evolving landscape of precision medicine. As research progresses, the unique attributes of CAR-NK cells offer a new avenue for therapeutic interventions, paving the way for a more effective and precise approach to cancer treatment.

Oncometabolite 2-hydroxyglutarate regulates anti-tumor immunity

"Oncometabolite" 2-hydroxyglutarate (2-HG) is an aberrant metabolite found in tumor cells, exerting a pivotal influence on tumor progression. Recent studies have unveiled its impact on the proliferation, activation, and differentiation of anti-tumor T cells. Moreover, 2-HG regulates the function of innate immune components, including macrophages, dendritic cells, natural killer cells, and the complement system. Elevated levels of 2-HG hinder α-KG-dependent dioxygenases (α-KGDDs), contributing to tumorigenesis by disrupting epigenetic regulation, genome integrity, hypoxia-inducible factors (HIF) signaling, and cellular metabolism. The chiral molecular structure of 2-HG produces two enantiomers: D-2-HG and L-2-HG, each with distinct origins and biological functions. Efforts to inhibit D-2-HG and leverage the potential of L-2-HG have demonstrated efficacy in cancer immunotherapy. This review delves into the metabolism, biological functions, and impacts on the tumor immune microenvironment (TIME) of 2-HG, providing a comprehensive exploration of the intricate relationship between 2-HG and antitumor immunity. Additionally, we examine the potential clinical applications of targeted therapy for 2-HG, highlighting recent breakthroughs as well as the existing challenges.

The Tumor Microenvironment and Immune Response in Breast Cancer

The complex interactions between cancer cells and their surrounding microenvironment are fundamental in determining tumor progression, response to therapy, and, ultimately, patient prognosis [...].