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

Radiotherapy modulates autophagy to reshape the tumor immune microenvironment to enhance anti-tumor immunity in esophageal cancer

The combination of radiotherapy and immunotherapy exerts synergistic antitumor in a range of human cancers, and also in esophageal cancer. Radiotherapy-induced tumor immune microenvironment (TIME) reprogramming is an essential basis for the synergistic antitumor between radiotherapy and immunotherapy. Radiotherapy can induce autophagy in tumor cells and immune cells of TIME, and autophagy activation is involved in the modification of immunological characteristics of TIME. The TIME landscape of esophageal cancer, especially ESCC, can be affected by radiotherapy or autophagy regulation. In this review, we depicted that local radiotherapy-induced autophagy could promote the maturation, migration, infiltration, and function of immune cells by complicated mechanisms to make TIME from immune "cold" to "hot", resulting in the synergistic antitumor of RT and IO. We argue that unraveling the relevance of radiotherapy-initiated autophagy to driving radiotherapy reprogramming TIME will open new ideas to explore new targets or more efficiently multimodal therapeutic interventions in ESCC.

Comprehensive analysis of the critical role of the epithelial mesenchymal transition subtype - TAGLN-positive fibroblasts in colorectal cancer progression and immunosuppression

Epithelial-mesenchymal transition (EMT) plays a pivotal role in tumor metastasis and immune suppression in colorectal cancer (CRC). However, the specific mechanisms of EMT and its relationship with the clinical prognosis and immunotherapy response in CRC patients remain unclear. In this study, we identified TAGLN-positive fibroblasts (TAGLN⁺Fib) as a cancer-associated fibroblast (CAF) subtype within the tumor microenvironment (TME) that promotes tumor metastasis and immune evasion. High EMT scores, strongly associated with TAGLN expression, were correlated with advanced tumor stages, poor prognosis, and resistance to immunotherapy. Functional experiments demonstrated that TAGLN knockdown significantly reduced CRC cell proliferation, migration, and EMT phenotypes in vitro and suppressed tumor growth in vivo. Furthermore, TAGLN⁺Fib closely interacted with MMP7-positive tumor epithelial cells and SPP1-positive macrophages, forming a pro-metastatic and immunosuppressive network. An EMT-TME risk model constructed using TAGLN⁺Fib exhibited robust predictive power for CRC prognosis and immunotherapy response. This study reveals the association of EMT scores with CRC prognosis and immunotherapy response, highlights TAGLN⁺Fib's critical role in tumor progression, and develops an EMT-TME risk model, offering insights for personalized CRC treatment and precision medicine.

Revisiting the role of cancer-associated fibroblasts in tumor microenvironment

Cancer-associated fibroblasts (CAFs) are integral components of the tumor microenvironment playing key roles in tumor progression, metastasis, and therapeutic resistance. However, challenges persist in understanding their heterogeneity, origin, and functional diversity. One major obstacle is the lack of standardized naming conventions for CAF subpopulations, with current systems failing to capture their full complexity. Additionally, the identification of CAFs is hindered by the absence of specific biomarkers, limiting the precision of diagnostic and therapeutic strategies. In vitro culture conditions often fail to maintain the in vivo characteristics of CAFs, which complicates their study and the translation of findings to clinical practice. Although current detection methods, such as antibodies, mRNA probes, and single-cell transcriptomics, offer insights into CAF biology, they lack standardization and fail to provide reliable quantitative measures. Furthermore, the dynamic interactions between CAFs, tumor cells, and immune cells within the TME remain insufficiently understood, and the role of CAFs in immune evasion and therapy resistance is an area of ongoing research. Understanding how CAFs influence drug resistance and the immune response is essential for developing more effective cancer therapies. This review aims to provide an in-depth analysis of the challenges in CAF research, propose future research directions, and emphasize the need for improved CAF-targeted therapeutic strategies. By addressing these gaps, it seeks to highlight the potential of CAFs as targets for overcoming therapeutic resistance and enhancing the efficacy of cancer treatments.

Translational study of the regulatory mechanism by which immune synapses enhance immune cell function

Immune synapses, which were initially discovered at the interface between antigen-presenting cells (APCs) and T cells, are special structures formed at the contact site between antigen-presenting cells and immune cells and constitute the structural basis for immune cells to kill tumours and synthesise antibodies. Their structures are very similar to those of neural synapses in the nervous system, and they contain different functional structural regions. With the development of cell visualization research, scientists have increasingly conducted in-depth research on immune synapses. At present, it is known that T cells, B cells, and NK cells can form different immune synapses with target cells. Immune synapses formed by different cell subsets as well as CAR-T cells have their own characteristics, mainly in terms of their structure, formation process and regulatory mechanism. Therefore, how to enhance immune cell killing function by enhancing immune synaptic function has long been a research hotspot. At present, the killing function of immune cells can be enhanced by influencing the signalling molecules of immune synapses and the cell microenvironment and modifying the structure of immune synapses. Through a review of the factors affecting immune synapses, we can better explore the target for enhancing immune system function.

Single-cell multi-stage spatial evolutional map of esophageal carcinogenesis

Cancer development involves the co-evolution of cancer cells and their surrounding microenvironment, yet the dynamics of this interaction within the physical architecture remains poorly understood. Here, we present a spatial transcriptomic map at single-cell resolution, encompassing 127 multi-stage fields of view from 43 patients, to chart the evolutionary trajectories of human esophageal squamous cell carcinoma (ESCC). By analyzing 6.4 million cells, we reveal that ESCC progression is driven by a proliferative epithelial cell subpopulation that acquires dedifferentiated and invasive characteristics. At the late precancerous stage, these cells disrupt the epithelial-stromal interface and recruit normal fibroblasts via JAG1-NOTCH1 signaling, transforming them into cancer-associated fibroblasts (CAFs). This interaction leads to the formation of a "CAF-Epi" (CAF and epithelial cell) niche at the tumor edge that shields the tumor from immune surveillance. The CAF-Epi niche formation is a key indicator of progression in ESCC and other squamous cell carcinomas and patient outcomes.

Tumor-derived colorectal cancer organoids induce a unique Treg cell population by directing CD4+ T cell differentiation

In colorectal cancer (CRC), increased numbers of tumor-infiltrating CD4+ regulatory T (Treg) cells correlate with tumor development, immunotherapy failure, and poor prognosis. To assess how CRC tumors directly modulate Treg cell differentiation, we developed an in vitro co-culture system using CD4+ T cells from Foxp3eGFP mice and CRC tumor-derived organoids. Co-culture resulted in a significant increase in Treg cell numbers. RNA-sequencing identified a distinct transcriptional profile of CRC organoid-induced Treg cells, with upregulation of genes associated with CRC Treg cells in vivo. High expression of genes upregulated in CRC organoid-induced Treg cells correlates with shorter progression-free intervals and overall survival in CRC patients. Human CRC organoids similarly induced Treg cells with enhanced suppressive capacity and upregulated genes linked to CRC Treg cells in vivo. This model provides insights into how CRC tumors modulate CD4+ T cell differentiation and can identify approaches to disrupt Treg cells and stimulate anti-tumor immunity.

Unravelling the role of ubiquitin-specific proteases in breast carcinoma: insights into tumour progression and immune microenvironment modulation

Breast cancer is a prevalent malignancy worldwide, and its treatment has increasingly shifted towards precision medicine, with immunotherapy emerging as a key therapeutic strategy. Deubiquitination, an essential epigenetic modification, is regulated by deubiquitinating enzymes (DUBs) and plays a critical role in immune function and tumor progression. Ubiquitin-specific proteases (USPs), a prominent subgroup of DUBs, are involved in regulating immune cell functions, antigen processing, and T cell development in the context of breast cancer. Certain USPs also modulate the differentiation of immune cells, such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), within the breast cancer immune microenvironment. Furthermore, several USPs influence the expression of PD-L1, thus affecting the efficacy of immune checkpoint inhibitors. The overexpression of USPs may promote immune evasion, contributing to the development of treatment resistance. This review elucidates the role of USPs in modulating the immune microenvironment and immune responses in breast cancer. Additionally, it discusses effective strategies for combining USP inhibitors with other therapeutic agents to enhance treatment outcomes. Therefore, targeting USPs presents the potential to enhance the efficacy of immunotherapy and overcome drug resistance, offering a more effective treatment strategy for breast cancer patients.

Antigen-presenting fibroblasts: emerging players in immune modulation and therapeutic targets

Antigen-presenting fibroblasts are a newly recognized subset that challenges the traditional view of these cells as mere structural components. Under pathological or environmental stimuli, fibroblasts acquire antigen-presenting capabilities through the expression of MHC-II molecules and co-stimulatory factors, enabling them to interact with T cells and modulate immune responses. These specialized fibroblasts have been identified across various tissues and diseases, where they play context-dependent roles, either amplifying immune dysregulation or contributing to immune homeostasis. This review synthesizes recent advances in understanding the origins, activation, and functions of antigen-presenting fibroblasts. It highlights their role in promoting pathogenic immune responses and offering therapeutic opportunities through targeted modulation. Advancing our understanding of antigen-presenting fibroblasts holds great promise for developing innovative approaches to immune modulation and therapy across a range of diseases.

Promotion Mechanisms of Stromal Cell-Mediated Lung Cancer Development Within Tumor Microenvironment

Lung cancer, with its high incidence and mortality rates, has garnered significant attention in the medical community. The tumor microenvironment (TME), composed of tumor cells, stromal cells, extracellular matrix, surrounding blood vessels, and other signaling molecules, plays a pivotal role in the development of lung cancer. Stromal cells within the TME hold potential as therapeutic targets for lung cancer treatment. However, the precise and comprehensive mechanisms by which stromal cells contribute to lung cancer progression have not been fully elucidated. This review aims to explore the mechanisms through which stromal cells in the tumor microenvironment promote lung cancer development, with a particular focus on how immune cells, tumor-associated fibroblasts, and endothelial cells contribute to immune suppression, inflammation, and angiogenesis. The goal is to provide new insights and potential strategies for the diagnosis and treatment of lung cancer.

Single-cell and spatial-resolved profiling reveals cancer-associated fibroblast heterogeneity in colorectal cancer metabolic subtypes

BACKGROUND

Colorectal cancer (CRC) presents significant treatment challenges due to its high heterogeneity and complex intercellular interactions. Further exploration of CRC subtypes and interactions among tumor-specific clusters will facilitate the development of personalized treatment strategies.

METHODS

Single-cell RNA sequencing and bulk RNA sequencing datasets were integrated to determine CRC metabolic subtypes by hierarchical clustering. The analysis was further extended to cellchat, pseudotime, immune infiltration, and clinicopathological relevance to explore the characteristics of secreted frizzled related protein 2 (SFRP2) + cancer-associated fibroblast (CAF) clusters, and validated by spatial transcriptomics (ST), in vivo experiments, and multiple immunohistochemistry (mIHC).

RESULTS

CRC samples were stably classified into three heterogeneous metabolic subtypes, each exhibiting different microenvironment and CAF heterogeneity, particularly in the distribution of SFRP2 + CAF, which was aligned with metabolic activity. SFRP2 + CAF exhibits high extracellular matrix (ECM) activity and is closely involved in cellular communication, not only promoting the malignant progression of cancer cells but also inducing the differentiation of Tregs. Compared to responders of chemotherapy, the proportion of SFRP2 + CAFs is significantly increased in non-responders. Importantly, mIHC and ST analyses confirm that cancer cells with low expression of agmatinase (AGMAT) can recruit SFRP2 + CAFs, and Treg infiltration surrounding SFRP2 + CAFs was observed. AGMAT combined with oxaliplatin showed the best efficacy in vivo, which may be associated with the inhibition of SFRP2 + CAF infiltration.

CONCLUSIONS

Our study identified and described the potential protumor biological properties of SFRP2 + CAFs, and AGMAT may be a valuable target for disrupting their properties.

Cancer-associated fibroblasts: heterogeneity, tumorigenicity and therapeutic targets

Cancer, characterized by its immune evasion, active metabolism, and heightened proliferation, comprises both stroma and cells. Although the research has always focused on parenchymal cells, the non-parenchymal components must not be overlooked. Targeting cancer parenchymal cells has proven to be a formidable challenge, yielding limited success on a broad scale. The tumor microenvironment(TME), a critical niche for cancer cell survival, presents a novel way for cancer treatment. Cancer-associated fibroblast (CAF), as a main component of TME, is a dynamically evolving, dual-functioning stromal cell. Furthermore, their biological activities span the entire spectrum of tumor development, metastasis, drug resistance, and prognosis. A thorough understanding of CAFs functions and therapeutic advances holds significant clinical implications. In this review, we underscore the heterogeneity of CAFs by elaborating on their origins, types and function. Most importantly, by elucidating the direct or indirect crosstalk between CAFs and immune cells, the extracellular matrix, and cancer cells, we emphasize the tumorigenicity of CAFs in cancer. Finally, we highlight the challenges encountered in the exploration of CAFs and list targeted therapies for CAF, which have implications for clinical treatment.

Single-cell resolution spatial analysis of antigen-presenting cancer-associated fibroblast niches

Recent studies have identified a unique subtype of cancer-associated fibroblasts (CAFs) termed antigen-presenting CAFs (apCAFs), which remain the least understood CAF subtype. To gain a comprehensive understanding of the origin and function apCAFs, we construct a fibroblast molecular atlas across 14 types of solid tumors. Our integration study unexpectedly reveals two distinct apCAF lineages present in most cancer types: one associated with mesothelial-like cells and the other with fibrocytes. Using a high-resolution single-cell spatial imaging platform, we characterize the spatial niches of these apCAF lineages. We find that mesothelial-like apCAFs are located near cancer cells, while fibrocyte-like apCAFs are associated with tertiary lymphoid structures. Additionally, we discover that both apCAF lineages can up-regulate the secreted protein SPP1, which facilitates primary tumor formation and peritoneal metastasis. Taken together, this study offers an unprecedented resolution in analyzing apCAF lineages and their spatial niches.

Subverting Attachment to Prevent Attacking: Alteration of Effector Immune Cell Migration and Adhesion as a Key Mechanism of Tumor Immune Evasion

Cell adhesion regulates specific migratory patterns, location, communication with other cells, physical interactions with the extracellular matrix, and the establishment of effector programs. Proper immune control of cancer strongly depends on all these events occurring in a highly accurate spatiotemporal sequence. In response to cancer-associated inflammatory signals, effector immune cells navigating the bloodstream shift from their patrolling exploratory migration mode to establish adhesive interactions with vascular endothelial cells. This interaction enables them to extravasate through the blood vessel walls and access the cancer site. Further adhesive interactions within the tumor microenvironment (TME) are crucial for coordinating their distribution in situ and for mounting an effective anti-tumor immune response. In this review, we examine how alterations of adhesion cues in the tumor context favor tumor escape by affecting effector immune cell infiltration and trafficking within the TME. We discuss the mechanisms by which tumors directly modulate immune cell adhesion and migration patterns to affect anti-tumor immunity and favor tumor evasion. We also explore indirect immune escape mechanisms that involve modifications of TME characteristics, such as vascularization, immunogenicity, and structural topography. Finally, we highlight the significance of these aspects in designing more effective drug treatments and cellular immunotherapies.

PD-L1 blockade immunotherapy rewires cancer-induced emergency myelopoiesis

Introduction

Immune checkpoint blockade (ICB) immunotherapy has revolutionized cancer treatment, demonstrating exceptional clinical responses in a wide range of cancers. Despite the success, a significant proportion of patients still fail to respond, highlighting the existence of unappreciated mechanisms of immunotherapy resistance. Delineating such mechanisms is paramount to minimize immunotherapy failures and optimize the clinical benefit.

Methods

In this study, we treated tumour-bearing mice with PD-L1 blockage antibody (aPD-L1) immunotherapy, to investigate its effects on cancer-induced emergency myelopoiesis, focusing on bone marrow (BM) hematopoietic stem and progenitor cells (HSPCs). We examined the impact of aPD-L1 treatment on HSPC quiescence, proliferation, transcriptomic profile, and functionality.

Results

Herein, we reveal that aPD-L1 in tumour-bearing mice targets the HSPCs in the BM, mediating their exit from quiescence and promoting their proliferation. Notably, disruption of the PDL1/PD1 axis induces transcriptomic reprogramming in HSPCs, observed in both individuals with Hodgkin lymphoma (HL) and tumour-bearing mice, shifting towards an inflammatory state. Furthermore, HSPCs from aPDL1-treated mice demonstrated resistance to cancer-induced emergency myelopoiesis, evidenced by a lower generation of MDSCs compared to control-treated mice.

Discussion

Our findings shed light on unrecognized mechanisms of action of ICB immunotherapy in cancer, which involves targeting of BM-driven HSPCs and reprogramming of cancer-induced emergency myelopoiesis.

Cancer associated fibroblasts and metabolic reprogramming: unraveling the intricate crosstalk in tumor evolution

Metabolic reprogramming provides tumors with an energy source and biofuel to support their survival in the malignant microenvironment. Extensive research into the intrinsic oncogenic mechanisms of the tumor microenvironment (TME) has established that cancer-associated fibroblast (CAFs) and metabolic reprogramming regulates tumor progression through numerous biological activities, including tumor immunosuppression, chronic inflammation, and ecological niche remodeling. Specifically, immunosuppressive TME formation is promoted and mediators released via CAFs and multiple immune cells that collectively support chronic inflammation, thereby inducing pre-metastatic ecological niche formation, and ultimately driving a vicious cycle of tumor proliferation and metastasis. This review comprehensively explores the process of CAFs and metabolic regulation of the dynamic evolution of tumor-adapted TME, with particular focus on the mechanisms by which CAFs promote the formation of an immunosuppressive microenvironment and support metastasis. Existing findings confirm that multiple components of the TME act cooperatively to accelerate the progression of tumor events. The potential applications and challenges of targeted therapies based on CAFs in the clinical setting are further discussed in the context of advancing research related to CAFs.