Targeting sphingosine 1-phosphate receptor 3 inhibits T-cell exhaustion and regulates recruitment of proinflammatory macrophages to improve antitumor efficacy of CAR-T cells against solid tumor

Role of Tumor-Associated Macrophages in Breast Cancer Immunotherapy

Breast cancer (BC) is the second leading cause of death among women worldwide. Immunotherapy has become an effective treatment for BC patients due to the rapid development of medical technology. Considerable breakthroughs have been made in research, marking the beginning of a new era in cancer treatment. Among them, various cancer immunotherapies such as immune checkpoint inhibitors (ICIs), cancer vaccines, and adoptive cell transfer are effective and have good prospects. The tumor microenvironment (TME) plays a crucial role in determining the outcomes of tumor immunotherapy. Tumor-associated macrophages (TAMs) are a key component of the TME, with an immunomodulatory effect closely related to the immune evasion of tumor cells, thereby affecting malignant progression. TAMs also significantly affect the therapeutic effect of ICIs (such as programmed death 1/programmed death ligand 1 (PD-1/PD-L1) inhibitors). TAMs are composed of multiple heterogeneous subpopulations, including M1 phenotypes macrophages (M1) and M2 phenotypes macrophages (M2). Furthermore, they mainly play an M2-like role and moderate a variety of harmful consequences such as angiogenesis, immunosuppression, and metastasis. Therefore, TAMs have become a key area of focus in the development of tumor therapies. However, several tumor immunotherapy studies demonstrated that ICIs are effective only in a small number of solid cancers, and tumor immunotherapy still faces relevant challenges in the treatment of solid tumors. This review explores the role of TAMs in BC immunotherapy, summarizing their involvement in BC development. It also explains the classification and functions of TAMs, outlines current tumor immunotherapy approaches and combination therapies, and discusses the challenges and potential strategies for TAMs in immuno-oncology treatments.

Cancer stem cell biomarkers and related signalling pathways

Cancer stem cells (CSCs) represent a distinct subset of neoplastic cells characterised by their heightened capacity for tumorigenesis. These cells are implicated in the facilitation of cancer metastasis, recurrence, and resistance to conventional therapeutic interventions. Extensive scientific research has been devoted to the identification of biomarkers and the elucidation of molecular mechanisms in order to improve targeted therapeutic approaches. Accurate identification of cancer stem cells based on biomarkers can provide a theoretical basis for drug combinations of malignant tumours. Targeted biomarker-based therapies also offer a silver lining for patients with advanced malignancies. This review aims comprehensively to consolidate the latest findings on CSCs biomarkers, targeted agents as well as biomarkers associated signalling pathways in well-established cancer types, thereby contributing to improved prognostic outcomes.

CD8+ T-cell exhaustion: Impediment to triple-negative breast cancer (TNBC) immunotherapy

CD8+ T-cell exhaustion has been identified as a significant contributor to immunosuppression and immune escape in triple-negative breast cancer (TNBC). Dysfunction due to cell exhaustion is characterized by reduced effector capacity and sustained expression of inhibitory receptors (IRs). The factors contributing to CD8+ T-cell exhaustion are multifaceted, encompassing external influences such as the upregulation of IRs, reduction of effector cytokines, and internal changes within the immune cell, including transcriptomic alterations, epigenetic landscape remodeling, and metabolomic shifts. The impact of the altered TNBC tumor microenvironment (TME) on Tex is also a critical consideration. The production of exhausted CD8+ T-cells (CD8+ Tex) is positively correlated with poor prognosis and reduced response rates to immunotherapy in TNBC patients, underscoring the urgent need for the development of novel TNBC immunotherapeutic strategies that target the mechanisms of CD8+ T-cell exhaustion. This review delineates the dynamic trajectory of CD8+ T-cell exhaustion development in TNBC, provides an update on the latest research advancements in understanding its pathogenesis, and offers insights into potential immunotherapeutic strategies.

Cellular dynamics of tumor microenvironment driving immunotherapy resistance in non-small-cell lung carcinoma

Immune checkpoint inhibitors (ICIs) have profoundly reshaped the treatment paradigm for non-small cell lung cancer (NSCLC). Despite these advancements, primary and secondary resistance to ICIs remain prevalent challenges in managing advanced NSCLC. Recent studies have highlighted the significant role of the tumor microenvironment (TME) in modulating treatment responses. This review aims to comprehensively examine the interactive roles of immune/stromal cells-such as T cells, B cells, neutrophils, macrophages, and CAFs within the TME, elucidating how these diverse cellular interactions contribute to immunotherapy resistance. It focuses on the dynamic interactions among diverse cell types such as the varying states of T cells under the influence of TME constituents like immune cells and cancer-associated fibroblasts (CAFs). By exploring the mechanisms involved in the complex cellular interactions, we highlight novel therapeutic targets and strategies aimed at overcoming resistance, thereby enhancing the efficacy of ICIs in NSCLC. Our synthesis of recent research provides critical insights into the multifaceted mechanisms of resistance and paves the way for the development of more effective, personalized treatment approaches.

Hypoxia-driven M2-polarized macrophages facilitate the epithelial-mesenchymal transition of glioblastoma via extracellular vesicles

Rationale: M2-like tumor-associated macrophages (TAMs) promote the malignant progression of glioblastomas. However, the mechanisms responsible for this phenomenon remain unclear. Methods: RT-PCR, Western blot and flow cytometry were used to evaluate the polarization status of macrophages. RT-PCR, western blot or/and immunohistochemistry was used to determine the expression of circ_0003137, PTBP1, PLOD3 and epithelial-mesenchymal transition (EMT) markers. Transwell assay was used to assess migration and invasion ability of tumor cells. RNA sequencing, bioinformatic analysis and Pearson correlation coefficient was performed to explore the relation between PTBP1 and circ_003137/PLOD3. In vivo experiment was used to determine the role of sh-circ_0003137-loaded nanoplatform. Results: Hypoxia promoted the polarization of macrophages towards M2-like TAMs in an HIF1α dependent manner. Then, M2-like TAMs could transport circ_0003137 enriched extracellular vesicles (EVs) to glioblastoma cells, upregulating circ_0003137 in glioblastoma cells. The circ_0003137 overexpression promoted the EMT of glioblastoma cells in vitro and in vivo. Mechanistically, circ_0003137 physically binds to polypyrimidine tract binding protein 1 (PTBP1), enhancing the stability of procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3) and promoting the EMT of glioblastoma cells. Moreover, a liposome-based nanoplatform that delivers shRNAs was established and used to encapsulate sh-circ_0003137. The fluorescence microscope tracer and cell co-culture assays demonstrated that the nanoplatform encapsulated with sh-circ_0003137 was stable and could penetrate the blood-brain barrier (BBB), finally reaching the central nervous system (CNS). The intracranial in situ tumor model showed that injecting the sh-circ_0003137-loaded nanoplatform via the tail vein significantly inhibited glioblastoma progression and improved the nude mice's survival. Conclusions: Hypoxia can drive macrophage polarization towards M2-like TAMs. Polarized M2-like TAMs can transport circ_0003137 to glioblastoma cells through EVs. Then, circ_0003137 promotes the EMT of glioblastomas by targeting the PTBP1/PLOD3 axis. Hence, targeting circ_0003137 might be a novel therapeutic strategy against glioblastoma.

Effects and action mechanism of gonadotropins on ovarian follicular cells: A novel role of Sphingosine-1-Phosphate (S1P). A review

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) control antral follicular growth by regulating several processes, such as the synthesis of hormones and signaling molecules, proliferation, survival, apoptosis, luteinization, and ovulation. To exert these effects, gonadotropins bind to their respective Gs protein-coupled receptors, activating the protein kinase A (PKA) pathway or recruiting Gq proteins to activate protein kinase C (PKC) signaling. Although the action mechanism of FSH and LH is clear, recently, it has been shown that both gonadotropins promote the synthesis of sphingosine-1-phosphate (S1P) in granulosa and theca cells through the activation of sphingosine kinase 1. Moreover, the inhibition of SPHKs reduces S1P synthesis, cell viability, and the proliferation of follicular cells in response to gonadotropins, and the addition of S1P to the culture medium increases the proliferation of granulosa and theca cells without apparent effects on sexual steroid synthesis. Therefore, we consider that S1P is a crucial signaling molecule that complements the canonical gonadotropin pathway to promote the proliferation and viability of granulosa and theca cells.

Comprehensive Analysis of a Platelet- and Coagulation-Related Prognostic Gene Signature Identifies CYP19A1 as a Key Tumorigenic Driver of Colorectal Cancer

BACKGROUND

The intricate interplay between the platelet-coagulation system and the progression of malignant tumors has profound therapeutic implications. However, a thorough examination of platelet and coagulation markers specific to colorectal cancer (CRC) is conspicuously absent in the current literature. Consequently, there is an urgent need for further exploration into the mechanistic underpinnings of these markers and their potential clinical applications.

METHODS

By integrating RNA-seq data and clinicopathological information from patients with CRC in the cancer genome atlas, we identified genes related to the platelet-coagulation system using weighted gene co-expression networks and univariate Cox analysis. We established a prognostic risk model based on platelet- and coagulation-related genes using Lasso Cox regression analysis and validated the model in two independent CRC cohorts. We explored potential biological functional disparities between high-risk and low-risk groups through comprehensive bioinformatics analysis.

RESULTS

Our findings indicate that colorectal cancer patients classified as high-risk generally exhibit poorer prognoses. Moreover, the model's risk scores were associated with the differential composition of the immune tumor microenvironment, suggesting its applicability to infer immunotherapy responsiveness. Cellular functional experiments and animal experiments indicated that CYP19A1 expression in CRC influences malignant phenotype and platelet activation.

CONCLUSIONS

In summary, we present a novel platelet- and coagulation-related risk model for prognostic assessment of patients with CRC and confirm the important role of CYP19A1 in promoting malignant progression of CRC.

NFS1 as a Candidate Prognostic Biomarker for Gastric Cancer Correlated with Immune Infiltrates

Background

Cysteine desulfurase (NFS1) is closely associated with the occurrence and development of human tumors, but its relationship with the prognosis and immunity of gastric cancer (GC) patients remains unclear.

Methods

To study the relationship between NFS1 and GC, GC-related data of TCGA were downloaded and analyzed. At the same time, Tumor Immune Estimation Resource (TIMER) and Kaplan‒Meier Plotter were used for relevant online analysis. Clinical samples were collected for immunohistochemical testing to validate the results.

Results

The mRNA and protein levels of NFS1 in GC tissues were significantly higher than those in normal tissues. In terms of the operating characteristic curve (ROC), the area under the curve (AUC) was 0.793, indicating that NFS1 had a high diagnostic value for GC. Further analysis showed that NFS1 expression was highly correlated with the depth of tumor invasion, lymph node metastasis, and tumor stage. Survival analysis showed that patients with high expression of NFS1 had a poorer prognosis, and NFS1 was an independent risk factor. Enrichment analysis by GO, KEGG, and GSEA showed that NFS1 was enriched in immune-related pathways. The expression of NFS1 was significantly positively correlated with the proportion of macrophages M0 and plasma cells but negatively correlated with the proportion of B cells memory, monocytes, and mast cells resting. In addition, NFS1 expression was significantly correlated with TMB levels and responses to immunotherapy.

Conclusion

Our results suggest that NFS1 may be a potential biomarker for the diagnosis and prediction of prognosis and immunotherapy efficacy in GC.

Looking ahead to targeting macrophages by CAR T- or NK-cells in blood cancers

INTRODUCTION

The bone marrow microenvironment (BME) is critical for healthy hematopoiesis and is often disrupted in hematologic malignancies. Tumor-associated macrophages (TAMs) are a major cell type in the tumor microenvironment (TME) and play a significant role in tumor growth and progression. Targeting TAMs and modulating their polarization is a promising strategy for cancer therapy.

AREAS COVERED

In this review, we discuss the importance of TME and different multiple possible targets to modulate immunosuppressive TAMs such as: CD123, Sphingosine 1-Phosphate Receptors, CD19/CD1d, CCR4/CCL22, CSF1R (CD115), CD24, CD40, B7 family proteins, MARCO, CD47, CD163, CD204, CD206 and folate receptors.

EXPERT OPINION

Innovative approaches to combat the immunosuppressive milieu of the tumor microenvironment in hematologic malignancies are of high clinical significance and may lead to increased survival, improved quality of life, and decreased toxicity of cancer therapies. Standard procedures will likely involve a combination of CAR T/NK-cell therapies with other treatments, leading to more comprehensive cancer care.

Reshaping the tumor immune microenvironment to improve CAR-T cell-based cancer immunotherapy

In many hematologic malignancies, the adoptive transfer of chimeric antigen receptor (CAR) T cells has demonstrated notable success; nevertheless, further improvements are necessary to optimize treatment efficacy. Current CAR-T therapies are particularly discouraging for solid tumor treatment. The immunosuppressive microenvironment of tumors affects CAR-T cells, limiting the treatment's effectiveness and safety. Therefore, enhancing CAR-T cell infiltration capacity and resolving the immunosuppressive responses within the tumor microenvironment could boost the anti-tumor effect. Specific strategies include structurally altering CAR-T cells combined with targeted therapy, radiotherapy, or chemotherapy. Overall, monitoring the tumor microenvironment and the status of CAR-T cells is beneficial in further investigating the viability of such strategies and advancing CAR-T cell therapy.

The potential role of CD8+ cytotoxic T lymphocytes and one branch connected with tissue-resident memory in non-luminal breast cancer

Advances in understanding the pathological mechanisms of breast cancer have resulted in the emergence of novel therapeutic strategies. However, triple-negative breast cancer (TNBC), a molecular subtype of breast cancer with a poor prognosis, lacks classical and general therapeutic targets, hindering the clinical application of several therapies to breast cancer. As insights into the unique immunity and molecular mechanisms of TNBC have become more extensive, immunotherapy has gradually become a valuable complementary approach to classical radiotherapy and chemotherapy. CD8+ cells are significant actors in the tumor immunity cycle; thus, research on TNBC immunotherapy is increasingly focused in this direction. Recently, CD8+ tissue-resident memory (TRM) cells, a subpopulation of CD8+ cells, have been explored in relation to breast cancer and found to seemingly play an undeniably important role in tumor surveillance and lymphocytic infiltration. In this review, we summarize the recent advances in the mechanisms and relative targets of CD8+ T cells, and discuss the features and potential applications of CD8+ TRM cells in non-luminal breast cancer immunotherapy.

CAR-based immunotherapy for breast cancer: peculiarities, ongoing investigations, and future strategies

Surgery, chemotherapy, and endocrine therapy have improved the overall survival and postoperative recurrence rates of Luminal A, Luminal B, and HER2-positive breast cancers but treatment modalities for triple-negative breast cancer (TNBC) with poor prognosis remain limited. The effective application of the rapidly developing chimeric antigen receptor (CAR)-T cell therapy in hematological tumors provides new ideas for the treatment of breast cancer. Choosing suitable and specific targets is crucial for applying CAR-T therapy for breast cancer treatment. In this paper, we summarize CAR-T therapy's effective targets and potential targets in different subtypes based on the existing research progress, especially for TNBC. CAR-based immunotherapy has resulted in advancements in the treatment of breast cancer. CAR-macrophages, CAR-NK cells, and CAR-mesenchymal stem cells (MSCs) may be more effective and safer for treating solid tumors, such as breast cancer. However, the tumor microenvironment (TME) of breast tumors and the side effects of CAR-T therapy pose challenges to CAR-based immunotherapy. CAR-T cells and CAR-NK cells-derived exosomes are advantageous in tumor therapy. Exosomes carrying CAR for breast cancer immunotherapy are of immense research value and may provide a treatment modality with good treatment effects. In this review, we provide an overview of the development and challenges of CAR-based immunotherapy in treating different subtypes of breast cancer and discuss the progress of CAR-expressing exosomes for breast cancer treatment. We elaborate on the development of CAR-T cells in TNBC therapy and the prospects of using CAR-macrophages, CAR-NK cells, and CAR-MSCs for treating breast cancer.

Engineered Adoptive T-Cell Therapies for Breast Cancer: Current Progress, Challenges, and Potential

Breast cancer remains a significant health challenge, and novel treatment approaches are critically needed. This review presents an in-depth analysis of engineered adoptive T-cell therapies (E-ACTs), an innovative frontier in cancer immunotherapy, focusing on their application in breast cancer. We explore the evolving landscape of chimeric antigen receptor (CAR) and T-cell receptor (TCR) T-cell therapies, highlighting their potential and challenges in targeting breast cancer. The review addresses key obstacles such as target antigen selection, the complex breast cancer tumor microenvironment, and the persistence of engineered T-cells. We discuss the advances in overcoming these barriers, including strategies to enhance T-cell efficacy. Finally, our comprehensive analysis of the current clinical trials in this area provides insights into the future possibilities and directions of E-ACTs in breast cancer treatment.