Olaparib Suppresses MDSC Recruitment via SDF1α/CXCR4 Axis to Improve the Anti-tumor Efficacy of CAR-T Cells on Breast Cancer in Mice

CAFs and T cells interplay: The emergence of a new arena in cancer combat

The interaction between the immune system and the tumor matrix has a huge impact on the progression and treatment of cancer. This paper summarizes and discusses the crosstalk between T cells and cancer-associated fibroblasts (CAFs). CAFs can also produce inhibitors that counteract the function of T cells and promote tumor immune escape, while T cells can also engage in complex two-way interactions with CAFs through direct cell contact, the exchange of soluble factors such as cytokines, and the remodeling of the extracellular matrix. Precise targeted intervention can effectively reverse tumor-promoting crosstalk between T cells and CAFs, improve anti-tumor immune response, and provide a new perspective for cancer treatment. Therefore, it is important to deeply understand the mechanism of crosstalk between T cells and CAFs. This review aims to outline the underlying mechanisms of these interactions and discuss potential therapeutic strategies that may become fundamental tools in the treatment of cancer, especially hard-to-cure cancers.

Expanding the Perspective on PARP1 and Its Inhibitors in Cancer Therapy: From DNA Damage Repair to Immunomodulation

The emergence of PARP inhibitors as a therapeutic strategy for tumors with high genomic instability, particularly those harboring BRCA mutations, has advanced cancer treatment. However, recent advances have illuminated a multifaceted role of PARP1 beyond its canonical function in DNA damage repair. This review explores the expanding roles of PARP1, highlighting its crucial interplay with the immune system during tumorigenesis. We discuss PARP1's immunomodulatory effects in macrophages and T cells, with a particular focus on cytokine expression. Understanding these immunomodulatory roles of PARP1 not only holds promise for enhancing the efficacy of PARP inhibitors in cancer therapy but also paves the way for novel treatment regimens targeting immune-mediated inflammatory diseases.

Research progress in tumor angiogenesis and drug resistance in breast cancer

Angiogenesis is considered a hallmark pathophysiological process in tumor development. Aberrant vasculature resulting from tumor angiogenesis plays a critical role in the development of resistance to breast cancer treatments, via exacerbation of tumor hypoxia, decreased effective drug concentrations within tumors, and immune-related mechanisms. Antiangiogenic therapy can counteract these breast cancer resistance factors by promoting tumor vascular normalization. The combination of antiangiogenic therapy with chemotherapy, targeted therapy, or immunotherapy has emerged as a promising approach for overcoming drug resistance in breast cancer. This review examines the mechanisms associated with angiogenesis and the interactions among tumor angiogenesis, the hypoxic tumor microenvironment, drug distribution, and immune mechanisms in breast cancer. Furthermore, this review provides a comprehensive summary of specific antiangiogenic drugs, and relevant studies assessing the reversal of drug resistance in breast cancer. The potential mechanisms underlying these interventions are discussed, and prospects for the clinical application of antiangiogenic therapy to overcome breast cancer treatment resistance are highlighted.

CAR-T therapy and targeted treatments: Emerging combination strategies in solid tumors

CAR-T cell therapies hold great potential in achieving long-term remission in patients suffering from malignancies. However, their efficacy in treating solid tumors is impeded by challenges such as limited infiltration, compromised cancer recognition, decreased cytotoxicity, heightened exhaustion, absence of memory phenotypes, and inevitable toxicity. To surmount these obstacles, researchers are exploring innovative strategies, including the integration of CAR-T cells with targeted inhibitors. The combination of CAR-T therapies with specific targeted drugs has shown promise in enhancing CAR-T cell infiltration into tumor sites, boosting their tumor recognition capabilities, strengthening their cytotoxicity, alleviating exhaustion, promoting the development of a memory phenotype, and reducing toxicity. By harnessing the synergistic potential, a wider range of patients with solid tumors may potentially experience favorable outcomes. To summarize the current combined strategies of CAR-T therapies and targeted therapies, outline the potential mechanisms, and provide insights for future studies, we conducted this review by collecting existing experimental and clinical evidence.

Tumor microenvironment as niche constructed by cancer stem cells: Breaking the ecosystem to combat cancer

BACKGROUND

Cancer stem cells (CSCs) are a distinct subpopulation of cancer cells with the capacity to constantly self-renew and differentiate, and they are the main driver in the progression of cancer resistance and relapse. The tumor microenvironment (TME) constructed by CSCs is the "soil" adapted to tumor growth, helping CSCs evade immune killing, enhance their chemical resistance, and promote cancer progression.

AIM OF REVIEW

We aim to elaborate the tight connection between CSCs and immunosuppressive components of the TME. We attempt to summarize and provide a therapeutic strategy to eradicate CSCs based on the destruction of the tumor ecological niche.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three main key concepts. First, we highlight that CSCs recruit and transform normal cells to construct the TME, which further provides ecological niche support for CSCs. Second, we describe the main characteristics of the immunosuppressive components of the TME, targeting strategies and summarize the progress of corresponding drugs in clinical trials. Third, we explore the multilevel insights of the TME to serve as an ecological niche for CSCs.

Understanding the immunosuppressive microenvironment of glioma: mechanistic insights and clinical perspectives

Glioblastoma (GBM), the predominant and primary malignant intracranial tumor, poses a formidable challenge due to its immunosuppressive microenvironment, thereby confounding conventional therapeutic interventions. Despite the established treatment regimen comprising surgical intervention, radiotherapy, temozolomide administration, and the exploration of emerging modalities such as immunotherapy and integration of medicine and engineering technology therapy, the efficacy of these approaches remains constrained, resulting in suboptimal prognostic outcomes. In recent years, intensive scrutiny of the inhibitory and immunosuppressive milieu within GBM has underscored the significance of cellular constituents of the GBM microenvironment and their interactions with malignant cells and neurons. Novel immune and targeted therapy strategies have emerged, offering promising avenues for advancing GBM treatment. One pivotal mechanism orchestrating immunosuppression in GBM involves the aggregation of myeloid-derived suppressor cells (MDSCs), glioma-associated macrophage/microglia (GAM), and regulatory T cells (Tregs). Among these, MDSCs, though constituting a minority (4-8%) of CD45+ cells in GBM, play a central component in fostering immune evasion and propelling tumor progression, angiogenesis, invasion, and metastasis. MDSCs deploy intricate immunosuppressive mechanisms that adapt to the dynamic tumor microenvironment (TME). Understanding the interplay between GBM and MDSCs provides a compelling basis for therapeutic interventions. This review seeks to elucidate the immune regulatory mechanisms inherent in the GBM microenvironment, explore existing therapeutic targets, and consolidate recent insights into MDSC induction and their contribution to GBM immunosuppression. Additionally, the review comprehensively surveys ongoing clinical trials and potential treatment strategies, envisioning a future where targeting MDSCs could reshape the immune landscape of GBM. Through the synergistic integration of immunotherapy with other therapeutic modalities, this approach can establish a multidisciplinary, multi-target paradigm, ultimately improving the prognosis and quality of life in patients with GBM.

Advances in molecular targeted drugs in combination with CAR-T cell therapy for hematologic malignancies

Molecular targeted drugs and chimeric antigen receptor (CAR) T cell therapy represent specific biological treatments that have significantly improved the efficacy of treating hematologic malignancies. However, they face challenges such as drug resistance and recurrence after treatment. Combining molecular targeted drugs and CAR-T cells could regulate immunity, improve tumor microenvironment (TME), promote cell apoptosis, and enhance sensitivity to tumor cell killing. This approach might provide a dual coordinated attack on cancer cells, effectively eliminating minimal residual disease and overcoming therapy resistance. Moreover, molecular targeted drugs can directly or indirectly enhance the anti-tumor effect of CAR-T cells by inducing tumor target antigen expression, reversing CAR-T cell exhaustion, and reducing CAR-T cell associated toxic side effects. Therefore, combining molecular targeted drugs with CAR-T cells is a promising and novel tactic for treating hematologic malignancies. In this review article, we focus on analyzing the mechanism of therapy resistance and its reversal of CAR-T cell therapy resistance, as well as the synergistic mechanism, safety, and future challenges in CAR-T cell therapy in combination with molecular targeted drugs. We aim to explore the benefits of this combination therapy for patients with hematologic malignancies and provide a rationale for subsequent clinical studies.

Challenges and strategies in relation to effective CAR-T cell immunotherapy for solid tumors

Chimeric Antigen Receptor T cell (CAR-T) therapy has revolutionized cancer treatment, but its application to solid tumors is limited. CAR-T cells have poor incapability of entering, surviving, proliferating, and finally exerting function in the tumor microenvironment. This review summarizes the main strategies related to enhancing the infiltration, efficacy, antigen recognition, and production of CAR-T in solid tumors. Additional applications of CAR-γδ T and macrophages are also discussed. We believe CAR-T will be a milestone in treating solid tumors once these problems are solved.

Chimeric antigen receptor-based immunotherapy in breast cancer: Recent progress in China

Breast cancer (BC) is the fourth most prevalent cancer in China. Despite conventional treatment strategies, BC patients often have poor therapeutic outcomes, leading to significant global cancer mortality rates. Chimeric antigen receptor (CAR)-based immunotherapy is a promising and innovative approach for cancer treatment that redirects immune cells to attack tumor cells expressing selected tumor antigens (TAs). T cells, natural killer (NK) cells, and macrophages, key components of the immune system, are used in CAR-based immunotherapies. Although remarkable progress has been made with CAR-T cells in hematologic malignancies, the application of CAR-based immunotherapy to BC has lagged. This is partly due to obstacles such as tumor heterogeneity, which is further associated with the TA and BC subtypes, and the immunosuppressive tumor microenvironment (TME). Several combinatorial approaches, including the use of immune checkpoint inhibitors, oncolytic viruses, and antitumor drugs, have been proposed to overcome these obstacles in BC treatment. Furthermore, several CAR-based immunotherapies for BC have been translated into clinical trials. This review provides an overview of the recent progress in CAR-based immunotherapy for BC treatment, including targeting of TAs, consideration of BC subtypes, assessment of the TME, and exploration of combinatorial therapies. The authors focused on preclinical studies and clinical trials of CAR-T cells, CAR-NK cells, and CAR-macrophages especially conducted in China, followed by an internal comparison and discussion of current limits. In conclusion, this review elucidates China's contribution to CAR-based immunotherapies for BC and provides inspiration for further research. PLAIN LANGUAGE SUMMARY: Despite conventional treatment strategies, breast cancer (BC) patients in China often have poor therapeutic outcomes. Chimeric antigen receptor (CAR)-based immunotherapy, a promising approach, can redirect immune cells to kill tumor cells expressing selected tumor antigens (TAs). However, obstacles such as TA selection, BC subtypes, and immunosuppressive tumor microenvironment still exist. Therefore, various combinatorial approaches have been proposed. This article elucidates several Chinese CAR-based preclinical and clinical studies in BC treatment with comparisons of foreign research, and CAR-immune cells are analyzed, providing inspiration for further research.

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.

Nanomaterials Boost CAR-T Therapy for Solid Tumors

T cell engineering, particularly via chimeric antigen receptor (CAR) modifications for enhancing tumor specificity, has shown efficacy in treating hematologic malignancies. The extension of CAR-T cell therapy to solid tumors, however, is impeded by several challenges: The absence of tumor-specific antigens, antigen heterogeneity, a complex immunosuppressive tumor microenvironment, and physical barriers to cell infiltration. Additionally, limitations in CAR-T cell manufacturing capacity and the high costs associated with these therapies restrict their widespread application. The integration of nanomaterials into CAR-T cell production and application offers a promising avenue to mitigate these challenges. Utilizing nanomaterials in the production of CAR-T cells can decrease product variability and lower production expenses, positively impacting the targeting and persistence of CAR-T cells in treatment and minimizing adverse effects. This review comprehensively evaluates the use of various nanomaterials in the production of CAR-T cells, genetic modification, and in vivo delivery. It discusses their underlying mechanisms and potential for clinical application, with a focus on improving specificity and safety in CAR-T cell therapy.

Ectopic CXCR2 expression cells improve the anti-tumor efficiency of CAR-T cells and remodel the immune microenvironment of pancreatic ductal adenocarcinoma

BACKGROUND

Recent progressions in CAR-T cell therapy against pancreatic ductal adenocarcinoma (PDAC) remain disappointing, which are partially attributed to the immunosuppressive microenvironment including macrophage-mediated T cell repletion.

METHODS

We first characterized the expression patterns of macrophage-relevant chemokines and identified CXCR2 as the key factor regulating T cell trafficking and tumor-specific accumulation in PDAC microenvironment. After that, we synthesized and introduced a CXCR2 expression cascade into Claudin18.2 CAR-T cells and compared the behaviors of CAR-T cells in vitro and in vivo. The therapeutic potential of CXCR2 CAR-T was evaluated in two different allogeneic models: subcutaneous allografts and metastatic PDAC models.

RESULTS

The results showed that CXCR2 CAR-T not only reduced the size of allografted PDAC tumors, but also completely eliminated the formation of metastases. Lastly, we investigated the tumor tissues and found that expression of ectopic CXCR2 significantly improved tumor-targeted infiltration and residence of T cells and reduced the presence of MDSCs and CXCR2 + macrophages in PDAC microenvironment.

CONCLUSION

Our studies suggested that ectopic CXCR2 played a significant and promising role in improving the efficiency of CAR-T therapy against primary and metastatic PDAC and partially reversed the immune-suppressive microenvironment.

Study on the mechanism of MDSC-platelets and their role in the breast cancer microenvironment

Myeloid-derived suppressor cells (MDSCs) are key immunosuppressive cells in the tumor microenvironment (TME) that play critical roles in promoting tumor growth and metastasis. Tumor-associated platelets (TAPs) help cancer cells evade the immune system and promote metastasis. In this paper, we describe the interaction between MDSCs and TAPs, including their generation, secretion, activation, and recruitment, as well as the effects of MDSCs and platelets on the generation and changes in the immune, metabolic, and angiogenic breast cancer (BC) microenvironments. In addition, we summarize preclinical and clinical studies, traditional Chinese medicine (TCM) therapeutic approaches, and new technologies related to targeting and preventing MDSCs from interacting with TAPs to modulate the BC TME, discuss the potential mechanisms, and provide perspectives for future development. The therapeutic strategies discussed in this review may have implications in promoting the normalization of the BC TME, reducing primary tumor growth and distant lung metastasis, and improving the efficiency of anti-tumor therapy, thereby improving the overall survival (OS) and progression-free survival (PFS) of patients. However, despite the significant advances in understanding these mechanisms and therapeutic strategies, the complexity and heterogeneity of MDSCs and side effects of antiplatelet agents remain challenging. This requires further investigation in future prospective cohort studies.

The CXCL16-CXCR6 axis in glioblastoma modulates T-cell activity in a spatiotemporal context

Introduction

Glioblastoma multiforme (GBM) pathobiology is characterized by its significant induction of immunosuppression within the tumor microenvironment, predominantly mediated by immunosuppressive tumor-associated myeloid cells (TAMCs). Myeloid cells play a pivotal role in shaping the GBM microenvironment and influencing immune responses, with direct interactions with effector immune cells critically impacting these processes.

Methods

Our study investigates the role of the CXCR6/CXCL16 axis in T-cell myeloid interactions within GBM tissues. We examined the surface expression of CXCL16, revealing its limitation to TAMCs, while microglia release CXCL16 as a cytokine. The study explores how these distinct expression patterns affect T-cell engagement, focusing on the consequences for T-cell function within the tumor environment. Additionally, we assessed the significance of CXCR6 expression in T-cell activation and the initial migration to tumor tissues.

Results

Our data demonstrates that CXCL16 surface expression on TAMCs results in predominant T-cell engagement with these cells, leading to impaired T-cell function within the tumor environment. Conversely, our findings highlight the essential role of CXCR6 expression in facilitating T-cell activation and initial migration to tumor tissues. The CXCL16-CXCR6 axis exhibits dualistic characteristics, facilitating the early stages of the T-cell immune response and promoting T-cell infiltration into tumors. However, once inside the tumor, this axis contributes to immunosuppression.

Discussion

The dual nature of the CXCL16-CXCR6 axis underscores its potential as a therapeutic target in GBM. However, our results emphasize the importance of carefully considering the timing and context of intervention. While targeting this axis holds promise in combating GBM, the complex interplay between TAMCs, microglia, and T cells suggests that intervention strategies need to be tailored to optimize the balance between promoting antitumor immunity and preventing immunosuppression within the dynamic tumor microenvironment.

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.

Advancing the frontiers of adaptive cell therapy: A transformative mechanistic journey from preclinical to clinical settings

Although the concept of using the patient's immune system to combat cancer has been around for a while, it is only in recent times that substantial progress has been achieved in this field. Over the last ten years, there has been a significant advancement in the treatment of cancer through immune checkpoint blockade. This treatment has been approved for multiple types of tumors. Another approach to modifying the immune system to detect tumor cells and fight them off is adaptive cell therapy (ACT). This therapy involves using T cells that have been modified with either T cell receptors (TCR) or chimeric antigen receptors (CAR) to target the tumor cells. ACT has demonstrated encouraging outcomes in different types of tumors, and clinical trials are currently underway worldwide to enhance this form of treatment. This review focuses on the advancements that have been made in ACT from preclinical to clinical settings till now.

Breast cancer immunotherapy: a comprehensive review

Cancer remains a major health problem despite numerous new medical interventions that have been introduced in recent years. One of the major choices for cancer therapy is so-called adoptive cell therapy (ACT). ACT can be performed using both innate immune cells, including dendritic cells (DCs), natural killer (NK) cells, and γδ T cells and acquired immune T cells. It has become possible to utilize these cells in both their native and modified states in clinical studies. Because of considerable success in cancer treatment, ACT now plays a role in advanced therapy protocols. Genetic engineering of autologous and allogeneic immune cells (T lymphocytes, NK cells, macrophages, etc.) with chimeric antigen receptors (CAR) is a powerful new tool to target specific antigens on cancer cells. The Food and Drug Administration (FDA) in the US has approved certain CAR-T cells for hematologic malignancies and it is hoped that their use can be extended to incorporate a variety of cells, in particular NK cells. However, the ACT method has some limitations, such as the risk of rejection in allogeneic engrafts. Accordingly, numerous efforts are being made to eliminate or minimize this and other complications. In the present review, we have developed a guide to breast cancer (BC) therapy from conventional therapy, through to cell-based approaches, in particular novel technologies including CAR with emphasis on NK cells as a new and safer candidate in this field as well as the more recent aptamer technology, which can play a major role in BC immunotherapy.

Hyaluronic acid-empowered nanotheranostics in breast and lung cancers therapy

Nanomedicine application in cancer therapy is an urgency because of inability of current biological therapies for complete removal of tumor cells. The development of smart and novel nanoplatforms for treatment of cancer can provide new insight in tumor suppression. Hyaluronic acid is a biopolymer that can be employed for synthesis of smart nanostructures capable of selective targeting CD44-overexpressing tumor cells. The breast and lung cancers are among the most malignant and common tumors in both females and males that environmental factors, lifestyle and genomic alterations are among the risk factors for their pathogenesis and development. Since etiology of breast and lung tumors is not certain and multiple factors participate in their development, preventative measures have not been completely successful and studies have focused on developing new treatment strategies for them. The aim of current review is to provide a comprehensive discussion about application of hyaluronic acid-based nanostructures for treatment of breast and lung cancers. The main reason of using hyaluronic acid-based nanoparticles is their ability in targeting breast and lung cancers in a selective way due to upregulation of CD44 receptor on their surface. Moreover, nanocarriers developed from hyaluronic acid or functionalized with hyaluronic acid have high biocompatibility and their safety is appreciated. The drugs and genes used for treatment of breast and lung cancers lack specific accumulation at cancer site and their cytotoxicity is low, but hyaluronic acid-based nanostructures provide their targeted delivery to tumor site and by increasing internalization of drugs and genes in breast and lung tumor cells, they improve their therapeutic index. Furthermore, hyaluronic acid-based nanostructures can be used for phototherapy-mediated breast and lung cancers ablation. The stimuli-responsive and smart kinds of hyaluronic acid-based nanostructures such as pH- and light-responsive can increase selective targeting of breast and lung cancers.

Single-cell profiling reveals the heterogeneity of NK cells during anti-PD-1 therapy in non-small-cell lung cancer

BACKGROUND

The efficacy of immune checkpoint inhibitors remains limited in non-small cell lung cancer (NSCLC). Natural killer (NK) cells serve as the key element of innate immunity and play an important role in anti-tumor immunity, the impact of NK cells on efficacy of anti-PD-1 therapy in NSCLC is worth exploring.

METHODS

We analyzed single-cell transcriptome data derived from biopsies of NSCLC patients receiving anti-PD-1 treatment. Immune cell subtypes were identified and further cell-cell communication were analyzed and verified.

RESULTS

We observed totally 6 distinct NK cells clusters in NSCLC infiltrating immune cells. It's worth noting that enrichment of immature NK cells was found in responsive group. A series of marker genes of immature NK cells were associated with anti-PD-1 response and related to immune regulation processes such as antigen processing, Th1, Th17 cells activation. Moreover, effector CD8+ T cells were significantly enriched in responsive group and showed similar trajectories with immature NK cells. Cell-cell communication analysis showed that immature NK cells showed strong interactions with Th17 cells and effector CD8+ T cells. Furthermore, when validating the expression of immature NK cells marker genes, we found that CXCR4 was associated with enriched infiltration of CD8+ T cells.

CONCLUSIONS

In conclusion, immature NK cells may facilitate the efficacy of anti-PD-1 therapy by interacting with Th1 cells, Th17 cells and enhancing infiltration of effector CD8+ T cells. Our data suggested that NK cells could be a promising target to improve the prognosis of NSCLC patients.

CXCR4-modified CAR-T cells suppresses MDSCs recruitment via STAT3/NF-κB/SDF-1α axis to enhance efficacy against pancreatic cancer

Claudin18.2 (CLDN18.2)-specific chimeric antigen receptor (CAR-T) cells displayed limited efficacy in CLDN18.2-positive pancreatic ductal adenocarcinoma (PDAC). Strategies are needed to improve the trafficking capacity of CLDN18.2-specific CAR-T cells. PDAC has a unique microenvironment that consists of abundant cancer-associated fibroblasts (CAFs), which could secrete stromal cell-derived factor 1α (SDF-1α), the ligand of CXCR4. Then, we constructed and explored CLDN18.2-targeted CAR-T cells with CXCR4 co-expression in treating immunocompetent mouse models of PDAC. The results indicated that CXCR4 could promote the infiltration of CAR-T cells and enhance their efficacy in vivo. Mechanistically, the activation of signal transducer and activator of transcription 3 (STAT3) signaling was impaired in CXCR4 CAR-T cells, which reduced the release of inflammatory factors, such as tumor necrosis factor-α, IL-6, and IL-17A. Then, the lower release of inflammatory factors suppressed SDF-1α secretion in CAFs via the nuclear factor κB (NF-κB) pathway. Therefore, the decreased secretion of SDF-1α in feedback decreased the migration of myeloid-derived suppressor cells (MDSCs) in tumor sites. Overall, our study demonstrated that CXCR4 CAR-T cells could traffic more into tumor sites and also suppress MDSC migration via the STAT3/NF-κB/SDF-1α axis to obtain better efficacy in treating CLDN18.2-positive pancreatic cancer. Our findings provide a theoretical rationale for CXCR4 CAR-T cell therapy in PDAC.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Targeting M-MDSCs enhances the therapeutic effect of BNCT in the 4-NQO-induced murine head and neck squamous cell carcinoma model

Purpose

Malignant head and neck squamous cell carcinoma (HNSCC) is characterized by a poor prognosis and resistance to conventional radiotherapy. Infiltrating myeloid-derived suppressive cells (MDSCs) is prominent in HNSCC and is linked to immune suppression and tumor aggressiveness. This study aimed to investigate the impact of boron neutron capture therapy (BNCT) on the MDSCs in the tumor microenvironment and peripheral blood and to explore the potential for MDSCs depletion combined with BNCT to reactivate antitumor immunity.

Methods and materials

Carcinogen, 4-NQO, -induced oral tumors were irradiated with a total physical dose of 2 Gy BNCT in Tsing Hua Open Reactor (THOR). Flow cytometry and immunohistochemistry accessed the dynamics of peripheral MDSCs and infiltrated MDSCs within the tumor microenvironment. Mice were injected with an inhibitor of CSF-1 receptor (CSF-1R), PLX3397, to determine whether modulating M-MDSCs could affect mice survival after BNCT.

Results

Peripheral CD11b+Ly6ChighLy6G- monocytic-MDSCs (M-MDSCs), but not CD11b+Ly6CloLy6Ghigh polymorphonuclear-MDSCs (PMN-MDSCs), increased as tumor progression. After BNCT treatment, there were temporarily decreased and persistent increases of M-MDSCs thereafter, either in peripheral blood or in tumors. The administration of PLX-3397 hindered BNCT-caused M-MDSCs infiltration, prolonged mice survival, and activated tumor immunity by decreasing tumor-associated macrophages (TAMs) and increasing CD8+ T cells.

Conclusion

M-MDSCs were recruited into 4-NQO-induced tumors after BNCT, and their number was also increased in peripheral blood. Assessment of M-MDSCs levels in peripheral blood could be an index to determine the optimal intervention window. Their temporal alteration suggests an association with tumor recurrence after BNCT, making M-MDSCs a potential intervention target. Our preliminary results showed that PLX-3397 had strong M-MDSCs, TAMs, and TIL (tumor-infiltrating lymphocyte) modulating effects that could synergize tumor control when combined with BNCT.

The role of inflammatory factors and T-cell subsets in the diagnosis of recurrence in epithelial ovarian cancer patients and the effect of olaparin treatment on them

BACKGROUND

The aim of the study is to investigate the role of serum inflammatory factors and T-cell subsets in the diagnosis of recurrence in epithelial ovarian cancer patients and the effect of olaparib on inflammatory factor and T-lymphocyte subsets in patients with recurrent epithelial ovarian cancer.

METHODS

In this study, 100 patients diagnosed as recurrent epithelial ovarian cancer in our hospital and 100 patients without recurrent epithelial ovarian cancer in the same period were selected. According to the treatment plan, the recurrent patients were divided into conventional therapy group (Paclitaxel and Carboplatin) and combined therapy group (Paclitaxel, Carboplatin, and olaparib). The levels of serum inflammatory factors were evaluated by enzyme-linked immunosorbent assay. The peripheral blood T-lymphocyte subsets in each group were detected by flow cytometry.

RESULTS

Compared with nonrecurrent patients, recurrent patients have higher serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels (p < .05), and lower interferon-γ (IFN-γ) level and the CD4+/CD8+ ratio. After adjusting for confounding factors, the results showed that the serum IL-6, IFN-γ, and TNF-α levels were influencing factors of recurrence in epithelial ovarian cancer patients. The area under the receiver operating curve and the sensitivity of serum TNF-α in predicting ovarian cancer recurrence were higher than those of IL-6 and IFN-γ. After secondary chemotherapy and/or olaparib maintenance treatment, the IL-6 (p < .001) and TNF-α (p < .001) levels in combined therapy group were lower than those in the conventional therapy, whereas the IFN-γ level (p < .001), the CD4+ T-cell proportion (p = .0069) and the CD4+/CD8+ ratio (p = .0201) were higher than those in the conventional therapy.

CONCLUSION

The serum IL-6, TNF-α, and IFN-γ levels were closely related to the recurrence of ovarian cancer. Olaparib maintenance treatment can significantly decrease the IL-6 and TNF-α level, and increase IFN-γ level and the CD4+/CD8+ ratio in patients with recurrent ovarian cancer.

Targeted Therapy for EWS-FLI1 in Ewing Sarcoma

Ewing sarcoma (EwS) is a rare and predominantly pediatric malignancy of bone and soft tissue in children and adolescents. Although international collaborations have greatly improved the prognosis of most EwS, the occurrence of macrometastases or relapse remains challenging. The prototypic oncogene EWS-FLI1 acts as an aberrant transcription factor that drives the cellular transformation of EwS. In addition to its involvement in RNA splicing and the DNA damage response, this chimeric protein directly binds to GGAA repeats, thereby modifying the transcriptional profile of EwS. Direct pharmacological targeting of EWS-FLI1 is difficult because of its intrinsically disordered structure. However, targeting the EWS-FLI1 protein complex or downstream pathways provides additional therapeutic options. This review describes the EWS-FLI1 protein partners and downstream pathways, as well as the related target therapies for the treatment of EwS.

Myeloid-derived suppressor cells: Key immunosuppressive regulators and therapeutic targets in cancer

Myeloid-derived suppressor cell (MDSC) mainly exists in tumor microenvironment (TME) and interferes with normal immune response of the body. These immature differentiated cells cooperate with tumor cells for immune escape and proliferation. The subtypes of MDSC are different in different organisms, and STAT become a high priority for the signaling pathway mediating the regulation of MDSC. The surface of MDSC cell population contains a variety of signal molecular receptors, and its differentiation degree is toilless to be chemotaxis by different factors. The role of MDSC in silencing T cells and promoting regulatory T cells (Treg) is particularly significant. This review mainly contains the origin of MDSC, the characteristics of subgroups, the focus of the study on MDSC heat molecules and signaling pathways, the relationship between MDSC and carcinoma, prognosis and hope to propose an overview of current MDSCs- targeting therapies so as to provide new ideas for cancer treatment.

Integrative multi-omics analyses unravel the immunological implication and prognostic significance of CXCL12 in breast cancer

Background

CXCL12 is a vital factor in physiological and pathological processes, by inducing migration of multiple cells. We aimed to comprehensively detect the role of CXCL12 in breast cancer, and explore novel CXCL12-related biomarkers through integrative multi-omics analyses to build a powerful prognostic model for breast cancer patients.

Methods

Immunohistochemistry analysis of the tissue microarray was performed to evaluate the correlation between CXCL12 expression levels and breast cancer patient outcomes. Combined single-nucleus and spatial transcriptomics data was used to uncover the expression distribution of CXCL12 in breast cancer microenvironment. CXCL12-related genes were identified by WGCNA analysis. Univariate Cox and LASSO regression analyses were then conducted to screen prognostic genes from above CXCL12-related genes, followed by the construction of the CXCL12-related prognostic signature, identification of risk groups, and external validation of the prognostic signature. Analyses of biological function, mutation landscape, immune checkpoint genes and immune cells, were performed to further reveal the differences between high/low-risk groups. Paired single-cell RNA-seq and bulk RNA-seq were analyzed to further disclose the association between the risk score and the complex tumor immune microenvironment. To screen potential therapeutic agents for breast cancer patients, analyses of gene-drug correlation and sensitivity to immunotherapy were conducted.

Results

High expression of CXCL12 was linked with a prolonged survival in breast cancer. A total of 402 genes were identified by WGCNA analysis and 11 genes, covering VAT1L, TMEM92, SDC1, RORB, PCSK9, NRN1, NACAD, JPH3, GJA1, BMP8B and ADAMTS2, were screened as the candidate prognostic genes. Next, the prognostic signature was built and validated using these genes to predict the outcomes of breast cancers. The high-risk group patients exhibited significantly inferior prognoses. The combination of the risk score and tumor mutational burden (TMB) had remarkably improved performance in predicting patient outcomes. Besides, high-risk group patients showed higher infiltration of M2-like macrophages. Finally, several potential anticancer drugs were identified. The high-risk group patients were more sensitive to immunotherapy but resistant to docetaxel.

Conclusions

CXCL12 has important immunological implication and prognostic significance in breast cancer. The CXCL12-related prognostic model could well predict the prognosis and treatment response of breast cancers.

MDSCs in breast cancer: an important enabler of tumor progression and an emerging therapeutic target

Women worldwide are more likely to develop breast cancer (BC) than any other type of cancer. The treatment of BC depends on the subtype and stage of the cancer, such as surgery, radiotherapy, chemotherapy, and immunotherapy. Although significant progress has been made in recent years, advanced or metastatic BC presents a poor prognosis, due to drug resistance and recurrences. During embryonic development, myeloid-derived suppressor cells (MDSCs) develop that suppress the immune system. By inhibiting anti-immune effects and promoting non-immune mechanisms such as tumor cell stemness, epithelial-mesenchymal transformation (EMT) and angiogenesis, MDSCs effectively promote tumor growth and metastasis. In various BC models, peripheral tissues, and tumor microenvironments (TME), MDSCs have been found to amplification. Clinical progression or poor prognosis are strongly associated with increased MDSCs. In this review, we describe the activation, recruitment, and differentiation of MDSCs production in BC, the involvement of MDSCs in BC progression, and the clinical characteristics of MDSCs as a potential BC therapy target.

Time to abandon CAR-T monotherapy for solid tumors

In recent decades, chimeric antigen receptor T (CAR-T) cell therapy has achieved dramatic success in patients with hematological malignancies. However, CAR-T cell therapy failed to effectively treat solid tumors as a monotherapy. By summarizing the challenges of CAR-T cell monotherapy for solid tumors and analyzing the underlying mechanisms of combinatorial strategies to counteract these hurdles, we found that complementary therapeutics are needed to improve the scant and transient responses of CAR-T cell monotherapy in solid tumors. Further data, especially data from multicenter clinical trials regarding efficacy, toxicity, and predictive biomarkers are required before the CAR-T combination therapy can be translated into clinical settings.

PARP inhibition synergizes with CD47 blockade to promote phagocytosis by tumor-associated macrophages in homologous recombination-proficient tumors

AIMS

PARP inhibitors (PARPi) are known to exert anti-tumor effects in patients with BRCA-mutated (BRCAmut) or homologous recombination (HR)-deficient cancer, but recent clinical investigations have suggested that this treatment may also be beneficial in patients with HR-proficient tumors. In this study, we aimed to investigate how PARPi exerts anti-tumor effects in non-BRCAmut tumors.

MAIN METHODS

BRCA wild-type, HR-deficient-negative ID8 and E0771 murine tumor cells were treated in vitro and in vivo with olaparib, a clinically approved PARPi. The effects on tumor growth in vivo were determined in immune-proficient and -deficient mice and alterations of immune cell infiltrations were analyzed with flow cytometry. Tumor-associated macrophages (TAMs) were further investigated with RNA-seq and flow cytometry. In addition, we confirmed olaparib's effect on human TAMs.

KEY FINDINGS

Olaparib did not affect HR-proficient tumor cell proliferation and survival in vitro. However, olaparib significantly decreased tumor growth in C57BL/6 and SCID-beige mice (defective in lymphoid development and NK cell activity). Olaparib increased macrophage numbers in the tumor microenvironment, and their depletion diminished the anti-tumor effects of olaparib in vivo. Further analysis revealed that olaparib improved TAM-associated phagocytosis of cancer cells. Notably, this enhancement was not solely reliant on the "Don't Eat Me" CD47/SIRPα signal. In addition, compared to monotherapy, the concomitant administration of αCD47 antibodies with olaparib improved tumor control.

SIGNIFICANCE

Our work provides evidence for broadening the application of PARPi in HR-proficient cancer patients and paves the way for developing novel combined immunotherapy to upgrade the anti-tumor effects of macrophages.

FAP-targeted CAR-T suppresses MDSCs recruitment to improve the antitumor efficacy of claudin18.2-targeted CAR-T against pancreatic cancer

PURPOSE

The claudin 18.2 (CLDN18.2) antigen is frequently expressed in malignant tumors, including pancreatic ductal adenocarcinoma (PDAC). Although CLDN18.2-targeted CAR-T cells demonstrated some therapeutic efficacy in PDAC patients, further improvement is needed. One of the major obstacles might be the abundant cancer-associated fibroblasts (CAFs) in the PDAC tumor microenvironment (TME). Targeting fibroblast activation protein (FAP), a vital characteristic of CAFs provides a potential way to overcome this obstacle. In this study, we explored the combined antitumor activity of FAP-targeted and CLDN18.2-targeted CAR-T cells against PDAC.

METHODS

Novel FAP-targeted CAR-T cells were developed. Sequential treatment of FAP-targeted and CLDN18.2-targeted CAR-T cells as well as the corresponding mechanism were explored in immunocompetent mouse models of PDAC.

RESULTS

The results indicated that the priorly FAP-targeted CAR-T cells infusion could significantly eliminate CAFs and enhance the anti-PDAC efficacy of subsequently CLDN18.2-targeted CAR-T cells in vivo. Interestingly, we observed that FAP-targeted CAR-T cells could suppress the recruitment of myeloid-derived suppressor cells (MDSCs) and promote the survival of CD8⁺ T cells and CAR-T cells in tumor tissue.

CONCLUSION

In summary, our finding demonstrated that FAP-targeted CAR-T cells could increase the antitumor activities of sequential CAR-T therapy via remodeling TME, at least partially through inhibiting MDSCs recruitment. Sequential infusion of FAP-targeted and CLDN18.2-targeted CAR-T cells might be a feasible approach to enhance the clinical outcome of PDAC.

Expressing IL-15/IL-18 and CXCR2 improve infiltration and survival of EGFRvIII-targeting CAR-T cells in breast cancer

Previously, we have generated EGFRvIII-targeting CAR-T cells and brought hope for treating advanced breast cancer. However, EGFRvIII-targeting CAR-T cells were defined limited anti-tumor efficacy, which might be due to reduced accumulation, persistence of therapeutic T cells in tumor site of breast cancer. CXCLs were highly expressed in tumor environment of breast cancer and CXCR2 is the main receptor for CXCLs. Here, CXCR2 could significantly improve the trafficking and tumor specific accumulation of CAR-T cells both in vivo and in vitro. However, the anti-tumor effect of CXCR2 CAR-T cells were weaken which might be results of the apoptosis of T cells. Cytokines could stimulate Tcell proliferation, such as interleukin (IL)-15 and IL-18. Then, we generated CXCR2 CAR with synthetic IL-15 or IL-18 production. Co-expressing IL-15 or IL-18 could significantly suppress the exhaustion and apoptosis of T cells and enhanced the anti-tumor activity of CXCR2 CAR-T cells in vivo. Further, coexpression IL-15 or IL-18 in CXCR2 CAR-T cells did not cause toxicity. These findings provide a potential therapy strategy of co-expression IL-15 or IL-18 in CXCR2 CAR-T cells for the treatment of advancing breast cancer in the future.

Targeting myeloid-derived suppressor cells in tumor immunotherapy: Current, future and beyond

Myeloid-derived suppressor cells (MDSCs) are one of the major negative regulators in tumor microenvironment (TME) due to their potent immunosuppressive capacity. MDSCs are the products of myeloid progenitor abnormal differentiation in bone marrow, which inhibits the immune response mediated by T cells, natural killer cells and dendritic cells; promotes the generation of regulatory T cells and tumor-associated macrophages; drives the immune escape; and finally leads to tumor progression and metastasis. In this review, we highlight key features of MDSCs biology in TME that are being explored as potential targets for tumor immunotherapy. We discuss the therapies and approaches that aim to reprogram TME from immunosuppressive to immunostimulatory circumstance, which prevents MDSC immunosuppression activity; promotes MDSC differentiation; and impacts MDSC recruitment and abundance in tumor site. We also summarize current advances in the identification of rational combinatorial strategies to improve clinical efficacy and outcomes of cancer patients, via deeply understanding and pursuing the mechanisms and characterization of MDSCs generation and suppression in TME.

Combining targeted DNA repair inhibition and immune-oncology approaches for enhanced tumor control

Targeted therapy and immunotherapy have revolutionized cancer treatment. However, the ability of cancer to evade the immune system remains a major barrier for effective treatment. Related to this, several targeted DNA-damage response inhibitors (DDRis) are being tested in the clinic and have been shown to potentiate anti-tumor immune responses. Seminal studies have shown that these agents are highly effective in a pan-cancer class of tumors with genetic defects in key DNA repair genes such as BRCA1/2, BRCA-related genes, ataxia telangiectasia mutated (ATM), and others. Here, we review the molecular consequences of targeted DDR inhibition, from tumor cell death to increased engagement of the anti-tumor immune response. Additionally, we discuss mechanistic and clinical rationale for pairing targeted DDRis with immunotherapy for enhanced tumor control. We also review biomarkers for patient selection and promising new immunotherapy approaches poised to form the foundation of next-generation DDRi and immunotherapy combinations.

Macrophages in Tumor-Associated Adipose Microenvironment Accelerate Tumor Progression

Adipose-tissue macrophages (ATMs), a complex ensemble of diverse macrophage subtypes, are prevalent in the tumor-adipose microenvironment (TAME) and facilitate tumor growth. However, the mechanisms in which the tumor-adipocyte crosstalk may enable the properties and plasticity of macrophages remain unclear. The single-cell RNA-sequence profiling reveals that a subset of macrophages expressed CD163, CCL2, and CCL5 in TAME, exhibiting an immunosuppressive subtype. It is demonstrated that CD163⁺ macrophages aggregate to surround adipocytes in breast cancer tissues. The expressions of CCL2 and CCL5 are also elevated in TAME and enable the recruitment and polarize macrophages. Mechanically, the level of exosomal miRNA-155 increased in the coculture of tumor cells and adipocytes, and then it promoted the generation and release of CCL2 and CCL5 from adipocytes by targeting the SOCS6/STAT3 pathway. Inhibition of exosomal miRNA-155 in tumor cells reduced the CCL2 and CCL5 levels in tumor-adipocytes coculture and further retarded tumor growth. Finally, the deletion of macrophages partially inhibited adipocyte-induced tumor proliferation. Likewise, inhibiting chemokines and their receptors or suppressing the phosphorylation of STAT3 decreased tumor burden in preclinical models. These results demonstrate that the niche factors in TAME, such as exosomal miRNA-155, regulate the function and polarity of macrophages to facilitate tumor progression.

Effect of crosstalk among conspirators in tumor microenvironment on niche metastasis of gastric cancer

In Traditional Chinese medicine, the metaphoric views of the human body are based on observations of nature guided by the theory of "Yin-Yang". The direct meanings of yin and yang are the bright and dark sides of an object, which often represent a wider range of opposite properties. When we shifted our view to gastric cancer (GC), we found that there are more distinctive Yin and Yang features in the mechanism of GC development and metastasis, which is observed in many mechanisms such as GC metastasis, immune escape, and stem cell homing. When illustrating this process from the yin-yang perspective, categorizing different cells in the tumor microenvironment enables new and different perspectives to be put forward on the mechanism and treatment of GC metastasis.

A Phase IB Trial of Autologous Cytokine-Induced Killer Cells in Combination with Sintilimab, Monoclonal Antibody Against Programmed Cell Death-1, plus Chemotherapy in Patients with Advanced Non-Small-Cell Lung Cancer

INTRODUCTION

Can the Cytokine-induced killer (CIK) cells in combination with immune checkpoint inhibitor further improve the efficacy of chemotherapy in non-small cell lung cancer (NSCLC) patients? What are the adverse reactions of this combination therapy? But these problems are not clear. Therefore, we conducted a phase 1b trial to evaluate the safety and efficacy of autologous CIK cells therapy combined with Sintilimab, antibody against programmed cell death-1, plus chemotherapy in untreated, advanced NSCLC patients.

PATIENTS AND METHODS

Patients with stage IIIB/IIIC/IV NSCLC received Sintilimab, platinum-based doublet chemotherapy, and CIK cells every 3 weeks for 4 cycles, then maintenance treatment with Sintilimab in squamous and with Sintilimab plus pemetrexed in non-squamous NSCLC until disease progression or unacceptable toxicity or 2 years. The primary endpoints were safety and objective response rate (ORR).

RESULTS

Thirty-four patients received the treatment. 94.1% of patients experienced treatment-related adverse events (TRAEs). Grade 3 or greater TRAEs occurred in 64.7% of patients. One (2.9%) patient died of grade 5 immune-related pneumonia. The ORR and DCR were 82.4% (95% CI, 65.5%-93.2%) and 100.0% (95% CI, 89.7%-100.0%), respectively. Objective responses were evaluated in 14 of 15 non-squamous patients (93.3%; 95% CI, 68.1%-99.8%) and in 14 of 19 squamous patients (73.7%; 95% CI, 48.8%-90.9%). Median PFS was 19.3 months (95% CI, 8.3 months to not available).

CONCLUSION

Autologous CIK cells immunotherapy in combination with Sintilimab plus chemotherapy was well tolerable and showed encouraging efficacy in patients with previously untreated, advanced NSCLC (ClinicalTrials.gov number, NCT03987867).

Radiation enhances the efficacy of EGFR-targeted CAR-T cells against triple-negative breast cancer by activating NF-κB/Icam1 signaling

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, with limited treatment options. Epidermal growth factor receptor (EGFR) is reported to be expressed in 50%-75% of TNBC patients, making it a promising target for cancer treatment. Here we show that EGFR-targeted chimeric antigen receptor (CAR) T cell therapy combined with radiotherapy provides enhanced antitumor efficacy in immunocompetent and immunodeficient orthotopic TNBC mice. Intriguingly, this combination therapy resulted in a substantial increase in the number of tumor-infiltrating CAR-T cells. The efficacy of this combination was independent of tumor radiosensitivity and lymphodepleting preconditioning. Cytokine profiling showed that this combination did not increase the risk of cytokine release syndrome (CRS). RNA sequencing (RNA-seq) analysis revealed that EGFR-targeting CAR-T therapy combined with radiotherapy increased the infiltration of CD8+ T and natural killer (NK) cells into tumors. Mechanistically, radiation significantly increased Icam1 expression on TNBC cells via activating nuclear factor κB (NF-κB) signaling, thereby promoting CAR-T cell infiltration and killing. These results suggest that CAR-T therapy combined with radiotherapy may be a promising strategy for TNBC treatment.

Combining inhibition of immune checkpoints and PARP: rationale and perspectives in cancer treatment

INTRODUCTION

Genomic instability resulting from the inability of cells to repair DNA damage is a breeding ground for immune checkpoint inhibitors (ICIs) and targeted treatments. Poly (ADP-ribose) polymerase inhibitors (PARPi) interfere with the efficient repair of DNA single-strand break damage inducing, mainly in tumors with existing defects in double strand DNA repair system, synthetic lethality.

AREAS COVERED

By amplifying the DNA damage and inducing immunogenic cell death PARPi leads tumor neoantigens to increase, upregulation of programmed death-ligand 1, and modulation of the tumor microenvironment facilitating a more intense antitumor immune response. In this review, we reported the immunological role of PARPi and the rational use of the combination with ICIs, evaluating data from combination clinical trials and discussing perspectives.

EXPERT OPINION

Several prospective combination studies to overcome existing limitations to PARPi and ICI single agents are currently ongoing. The identification of the different resistance mechanisms to PARPi and ICI as well as the development of accurate and predictive biomarkers of response should be a priority to identify the patients who may most benefit from this combination. Similarly, clarifying the role and interaction between the DNA damage repair pathways and the tumor immune microenvironment would increase success of the combination.

Immunosuppression in tumor immune microenvironment and its optimization from CAR-T cell therapy

Chimeric antigen receptor (CAR)-T cell therapy represents a landmark advance in personalized cancer treatment. CAR-T strategy generally engineers T cells from a specific patient with a new antigen-specificity, which has achieved considerable success in hematological malignancies, but scarce benefits in solid tumors. Recent studies have demonstrated that tumor immune microenvironment (TIME) cast a profound impact on the immunotherapeutic response. The immunosuppressive landscape of TIME is a critical obstacle to the effector activity of CAR-T cells. Nevertheless, every cloud has a silver lining. The immunosuppressive components also shed new inspiration on reshaping a friendly TIME by targeting them with engineered CARs. Herein, we summarize recent advances in disincentives of TIME and discuss approaches and technologies to enhance CAR-T cell efficacy via addressing current hindrances. Simultaneously, we firmly believe that by parsing the immunosuppressive components of TIME, rationally manipulating the complex interactions of immunosuppressive components, and optimizing CAR-T cell therapy for each patient, the CAR-T cell immunotherapy responsiveness for solid malignancies will be substantially enhanced, and novel therapeutic targets will be revealed.

The role of DNA damage repair (DDR) system in response to immune checkpoint inhibitor (ICI) therapy

As our understanding of the mechanisms of cancer treatment has increased, a growing number of studies demonstrate pathways through which DNA damage repair (DDR) affects the immune system. At the same time, the varied response of patients to immune checkpoint blockade (ICB) therapy has prompted the discovery of various predictive biomarkers and the study of combination therapy. Here, our investigation explores the interactions involved in combination therapy, accompanied by a review that summarizes currently identified and promising predictors of response to immune checkpoint inhibitors (ICIs) that are useful for classifying oncology patients. In addition, this work, which discusses immunogenicity and several components of the tumor immune microenvironment, serves to illustrate the mechanism by which higher response rates and improved efficacy of DDR inhibitors (DDRi) in combination with ICIs are achieved.

Pharmacological modulation of myeloid-derived suppressor cells to dampen inflammation

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population with potent suppressive and regulative properties. MDSCs’ strong immunosuppressive potential creates new possibilities to treat chronic inflammation and autoimmune diseases or induce tolerance towards transplantation. Here, we summarize and critically discuss different pharmacological approaches which modulate the generation, activation, and recruitment of MDSCs in vitro and in vivo, and their potential role in future immunosuppressive therapy.

Thyroid Cancer and Fibroblasts

Thyroid cancer is the most common type of endocrine cancer, and its prevalence continue to rise. Non-metastatic thyroid cancer patients are successfully treated. However, looking for new therapeutic strategies is of great importance for metastatic thyroid cancers that still lead to death. With respect to this, the tumor microenvironment (TME), which plays a key role in tumor progression, should be considered as a new promising therapeutic target to hamper thyroid cancer progression. Indeed, thyroid tumors consist of cancer cells and a heterogeneous and ever-changing niche, represented by the TME, which contributes to establishing most of the features of cancer cells. The TME consists of extracellular matrix (ECM) molecules, soluble factors, metabolites, blood and lymphatic tumor vessels and several stromal cell types that, by interacting with each other and with tumor cells, affect TME remodeling, cancer growth and progression. Among the thyroid TME components, cancer-associated fibroblasts (CAFs) have gained more attention in the last years. Indeed, recent important evidence showed that thyroid CAFs strongly sustain thyroid cancer growth and progression by producing soluble factors and ECM proteins, which, in turn, deeply affect thyroid cancer cell behavior and aggressiveness. Hence, in this article, we describe the thyroid TME, focusing on the desmoplastic stromal reaction, which is a powerful indicator of thyroid cancer progression and an invasive growth pattern. In addition, we discuss the origins and features of the thyroid CAFs, their influence on thyroid cancer growth and progression, their role in remodeling the ECM and their immune-modulating functions. We finally debate therapeutic perspectives targeting CAFs.

Immunotherapy and immunoengineering for breast cancer; a comprehensive insight into CAR-T cell therapy advancements, challenges and prospects

BACKGROUND

Breast cancer (BC) is a highly prevalent solid cancer with a high-rise infiltration of immune cells, turning it into a significant candidate for tumor-specific immunotherapies. Chimeric antigen receptor (CAR)-T cells are emerging as immunotherapeutic tools with genetically engineered receptors to efficiently recognize and attack tumor cells that express specific target antigens. Technological advancements in CAR design have provided five generations of CAR-T cells applicable to a wide range of cancer patients while boosting CAR-T cell therapy safety. However, CAR-T cell therapy is ineffective against breast cancer because of the loss of specified antigens, the immunosuppressive nature of the tumor and CAR-T cell-induced toxicities. Next-generation CAR-T cells actively pass through the tumor vascular barriers, persist for extended periods and disrupt the tumor microenvironment (TME) to block immune escape.

CONCLUSION

CAR-T cell therapy embodies advanced immunotherapy for BC, but further pre-clinical and clinical assessments are recommended to achieve maximized efficiency and safety.

Radiotherapy combined with immunotherapy: the dawn of cancer treatment

Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.

The landscape of chimeric antigen receptor T cell therapy in breast cancer: Perspectives and outlook

Chimeric antigen receptor-T (CAR-T) cell therapy is a revolutionary adoptive cell therapy, which could modify and redirect T cells to specific tumor cells. Since CAR-T cell therapy was first approved for B cell-derived malignancies in 2017, it has yielded unprecedented progress in hematological tumors and has dramatically reshaped the landscape of cancer therapy in recent years. Currently, cumulative evidence has demonstrated that CAR-T cell therapy could be a viable therapeutic strategy for solid cancers. However, owing to the immunosuppressive tumor microenvironment (TME) and heterogenous tumor antigens, the application of CAR-T cell therapy against solid cancers requires circumventing more challenging obstacles. Breast cancer is characterized by a high degree of invasiveness, malignancy, and poor prognosis. The review highlights the underlying targets of CAR-T cell therapy in breast cancer, summarizes the challenges associated with CAR-T cell therapy, and proposes the strategies to overcome these challenges, which provides a novel approach to breast cancer treatment.

Myeloid-derived suppressor cells in hematologic malignancies: two sides of the same coin

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of bone marrow cells originating from immature myeloid cells. They exert potent immunosuppressive activity and are closely associated with the development of various diseases such as malignancies, infections, and inflammation. In malignant tumors, MDSCs, one of the most dominant cellular components comprising the tumor microenvironment, play a crucial role in tumor growth, drug resistance, recurrence, and immune escape. Although the role of MDSCs in solid tumors is currently being extensively studied, little is known about their role in hematologic malignancies. In this review, we comprehensively summarized and reviewed the different roles of MDSCs in hematologic malignancies and hematopoietic stem cell transplantation, and finally discussed current targeted therapeutic strategies.Affiliation: Kindly check and confirm the processed affiliations are correct. Amend if any.correct

Chimeric Antigen Receptor (CAR)-T Cell Immunotherapy Against Thoracic Malignancies: Challenges and Opportunities

Different from surgery, chemical therapy, radio-therapy and target therapy, Chimeric antigen receptor-modified T (CAR-T) cells, a novel adoptive immunotherapy strategy, have been used successfully against both hematological tumors and solid tumors. Although several problems have reduced engineered CAR-T cell therapeutic outcomes in clinical trials for the treatment of thoracic malignancies, including the lack of specific antigens, an immunosuppressive tumor microenvironment, a low level of CAR-T cell infiltration into tumor tissues, off-target toxicity, and other safety issues, CAR-T cell treatment is still full of bright future. In this review, we outline the basic structure and characteristics of CAR-T cells among different period, summarize the common tumor-associated antigens in clinical trials of CAR-T cell therapy for thoracic malignancies, and point out the current challenges and new strategies, aiming to provide new ideas and approaches for preclinical experiments and clinical trials of CAR-T cell therapy for thoracic malignancies.

Cancer-associated fibroblasts in pancreatic cancer: new subtypes, new markers, new targets

Cancer-associated fibroblasts (CAFs) have conflicting roles in the suppression and promotion of cancer. Current research focuses on targeting the undesirable properties of CAFs, while attempting to maintain tumour-suppressive roles. CAFs have been widely associated with primary or secondary therapeutic resistance, and strategies to modify CAF function have therefore largely focussed on their combination with existing therapies. Despite significant progress in preclinical studies, clinical translation of CAF targeted therapies has achieved limited success. Here we will review our emerging understanding of heterogeneous CAF populations in tumour biology and use examples from pancreatic ductal adenocarcinoma to explore why successful clinical targeting of protumourigenic CAF functions remains elusive. Single-cell technologies have allowed the identification of CAF subtypes with a differential impact on prognosis and response to therapy, but currently without clear consensus. Identification and pharmacological targeting of CAF subtypes associated with immunotherapy response offers new hope to expand clinical options for pancreatic cancer. Various CAF subtype markers may represent biomarkers for patient stratification, to obtain enhanced response with existing and emerging combinatorial therapeutic strategies. Thus, CAF subtyping is the next frontier in understanding and exploiting the tumour microenvironment for therapeutic benefit. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Controlling Cell Trafficking: Addressing Failures in CAR T and NK Cell Therapy of Solid Tumours

The precision guiding of endogenous or adoptively transferred lymphocytes to the solid tumour mass is obligatory for optimal anti-tumour effects and will improve patient safety. The recognition and elimination of the tumour is best achieved when anti-tumour lymphocytes are proximal to the malignant cells. For example, the regional secretion of soluble factors, cytotoxic granules, and cell-surface molecule interactions are required for the death of tumour cells and the suppression of neovasculature formation, tumour-associated suppressor, or stromal cells. The resistance of individual tumour cell clones to cellular therapy and the hostile environment of the solid tumours is a major challenge to adoptive cell therapy. We review the strategies that could be useful to overcoming insufficient immune cell migration to the tumour cell mass. We argue that existing 'competitive' approaches should now be revisited as complementary approaches to improve CAR T and NK cell therapy.

Advances in CAR-T Cell Genetic Engineering Strategies to Overcome Hurdles in Solid Tumors Treatment

During this last decade, adoptive transfer of T lymphocytes genetically modified to express chimeric antigen receptors (CARs) emerged as a valuable therapeutic strategy in hematological cancers. However, this immunotherapy has demonstrated limited efficacy in solid tumors. The main obstacle encountered by CAR-T cells in solid malignancies is the immunosuppressive tumor microenvironment (TME). The TME impedes tumor trafficking and penetration of T lymphocytes and installs an immunosuppressive milieu by producing suppressive soluble factors and by overexpressing negative immune checkpoints. In order to overcome these hurdles, new CAR-T cells engineering strategies were designed, to potentiate tumor recognition and infiltration and anti-cancer activity in the hostile TME. In this review, we provide an overview of the major mechanisms used by tumor cells to evade immune defenses and we critically expose the most optimistic engineering strategies to make CAR-T cell therapy a solid option for solid tumors.