These findings identify a tumor-adapted MC state that orchestrates immune evasion and tissue remodeling during CRC progression, supporting the notion that MC are reprogrammed toward an immune-suppressive and pro-tumorigenic phenotype.
Abstract
Mast cells (MCs) are multifunctional immune cells with context-dependent functions in cancer. In colorectal cancer (CRC), their contribution remains debated, suggesting that distinct MC subsets may either support tumor progression or promote anti-tumor immunity. Using single-cell RNA sequencing in a mouse model of inflammation-driven CRC, we uncovered extensive MC plasticity during tumor progression. Transcriptomic profiling and pseudotime trajectory analysis revealed a transition from precursor-like MCs exclusively present in adjacent tissue to differentiated tumor-associated MC (TAMC) subsets. TAMCs displayed a distinct repertoire of proteases and pro-inflammatory cytokines, contributing to increased vascular permeability and recruitment of additional immune cells. Moreover, TAMCs exhibited upregulation of molecules with immunosuppressive potential and underwent a tumor microenvironment (TME)-driven metabolic reprogramming. Accordingly, antibody-mediated MC depletion reduced tumor burden. Notably, most of the transcriptional features identified in a murine CRC model were recapitulated in human CRC, supporting the translational relevance of this MC program. Our findings identify a tumor-adapted MC state that orchestrates immune evasion and tissue remodeling during CRC progression, supporting the notion that MC are reprogrammed toward an immune-suppressive and pro-tumorigenic phenotype.
Introduction Colorectal cancer (CRC) is a heterogeneous malignancy and a major cause of cancer-related mortality worldwide. Cancer-associated fibroblasts (CAFs) accumulate in tumors and correlate with poor patient survival, suggesting a central role in immune regulation. Patient-derived organoids (PDO) maintain the intra-tumoral cellular heterogeneity of the original tissue, thus, they represent one of the best methods to study human cancers. The tumor microenvironment (TME) contains diverse immune cell populations, including innate lymphoid cells (ILCs), yet how stromal components influence cytokine-driven tumor–immune interactions remains unclear. Methods PDOs from CRC patients were used to screen TME-derived cytokines affecting tumor growth. Organoid-forming efficiency and signaling pathway activation were analyzed following cytokine stimulation in the presence or absence of CAFs. Tumor-infiltrating ILC subsets were characterized in patient samples, and co-culture systems were employed to assess cytokine production and stromal–immune interactions. Results IL-22 was identified as a cytokine that increased PDO-forming efficiency without activating fibroblasts. Although IL-22 typically signals through the JAK–STAT pathway, it unexpectedly activates MAPK signaling in PDO cells. Interestingly, interferon-γ (IFNγ) showed only partial cytotoxic effects on CRC cells. Tumor tissues contained both IFNγ-producing ILC1 and IL-22/IL-17A–producing ILC3 populations. Co-culture with PDOs selectively induced IL-22, but not IL-17A, production in ILC3 cells. Importantly, IL-22 enhanced organoid formation only in the absence of CAFs, whereas IFNγ activity was largely unaffected by stromal context. Discussion These findings demonstrate that CAFs modulate local immunity by selectively masking ILC3-derived IL-22 signaling while preserving ILC1-mediated IFNγ responses. This study emphasizes the importance of stromal context in interpreting cytokine function in CRC and reveals a previously unrecognized mechanism of stromal–immune crosstalk within the TME.
S. Hajdo, Z. Komlósi, B. Érsek et al.· Frontiers in Immunology· 0 citations
Introduction Mast cells (MCs) play important roles in allergic reactions and tissue homeostasis; however, their functions in esophageal squamous cell carcinoma (ESCC) remain controversial. Understanding the heterogeneity and functional states of MCs in ESCC is essential for elucidating their roles in tumor progression and immune regulation. Methods single-cell RNA sequencing (scRNA-seq) data from 84 ESCC samples across four independent cohorts were analyzed to identify MC subtypes, which were further validated using bulk RNA-seq and immunofluorescence staining. Functional assays were performed to assess the effects of stem cell factor (SCF)-stimulated MCs on ESCC cell proliferation, migration, and apoptosis. Spatial transcriptomics were used to investigate MC interactions within the tumor microenvironment (TME). Results MC abundance was significantly reduced in ESCC tissues compared with normal esophageal tissues, as confirmed by bulk RNA-seq and IHC analyses. scRNA-seq revealed five distinct MC subtypes in ESCC: T-type-activated MC, T-type-resting MC, TC-type-activated MC, TC-type-resting MC and proliferating MC. Resting MCs localized to normal and stromal regions, whereas activated MCs were enriched in stromal and tumor regions, with their proportion significantly elevated in tumor tissues. SCF activated MCs via the c-Kit pathway, promoting TNF-α release and tumor cell apoptosis. Spatial and cell-cell communication analyses revealed extensive MC interactions with stromal and immune cells. Activated MC abundance positively correlated with T-cell infiltration and favorable ESCC prognosis. Conclusions Our findings demonstrate that MCs exhibit distinct functional states in ESCC and regulate tumor progression. T-type-activated MCs, characterized by enhanced TNF-α expression, may contribute to anti-tumor immunity. These findings provide new insights into MC heterogeneity in ESCC and support their potential relevance in immunotherapy.
Yiren Huang, Zheyi Chen, Bingqian Zhou et al.· Frontiers in Immunology· 0 citations
This study comprehensively maps the coevolution of malignant thyrocyte plasticity and the immunosuppressive metastatic niche in thyroid cancer and provides a robust molecular rationale for developing next-generation immunotherapeutic strategies tailored to thyroid cancer.
Shu-hang Xu, Yaorong Su, Senmin Zhang et al.· Oncoimmunology· 0 citations
Triple-negative breast cancer (TNBC) is an aggressive and immunogenic subtype lacking targeted therapies. While tumor-derived exosomes are known to modulate immune function, their direct impact on human T cell plasticity and antigen specificity remains poorly defined. Here, we conducted a comprehensive single-cell multiomic analysis of primary human T cells exposed to exosomes derived from 17 genomically diverse TNBC cell lines and 35 patient samples. Integrating single-cell RNA-seq, V(D)J sequencing, non-coding RNA profiling, bulk and single-cell cytokine analyses, we uncovered conserved and subtype-specific immunomodulatory programs induced by TNBC exosomes. Exosome-treated T cells displayed skewing toward regulatory and dysfunctional phenotypes, including Th17-like, Treg, and PD-1⁺/PD-L1⁺ Tfh cells. Functional profiling revealed suppression of early activation markers and cytokine responses, alongside selective preservation of cytotoxic features in γδ T and NKT subsets. Transcriptomic and miRNA network analyses demonstrated widespread downregulation of immune effector genes (e.g., HBEGF and TNFSF9) mediated by exosome-delivered regulatory miRNAs (has-miR-98-5p). Notably, exosome-stimulated T cells displayed distinct clonotypic expansions, characterized by the emergence of five tumor-specific γδ TCR clonotypes and 30 unique αβ TCR CDR3 sequences that were absent in mock-treated controls, underscoring the role of exosomes in shaping TCR repertoire dynamics.
Sanam Rezaei Benam, S. Maleknia, Kent Williams et al.· Signal Transduction and Targ...· 0 citations
Integrative single-cell RNA sequencing analysis of publicly available datasets from non-small cell lung cancer and breast cancer is performed to systematically map transcriptional heterogeneity and regulatory networks within the TME, providing a systems-level framework of TME organization.
M. O. Odubote, Chiemeka Elochi Emeribe· bioRxiv· 0 citations
Introduction Cutaneous squamous cell carcinoma (cSCC) is a common keratinocyte-derived malignancy whose progression is strongly influenced by the tumor microenvironment. Although recent studies have begun to describe cellular diversity in squamous cell carcinomas, the regulatory architecture coordinating epithelial, immune, and stromal interactions in cSCC remains incompletely understood. Methods We performed single-cell RNA sequencing on matched tumor tissues, adjacent normal skin, and peripheral blood from patients with cSCC to construct an integrated cellular landscape of the tumor ecosystem. Lineage trajectory analysis, transcription factor activity inference, and ligand–receptor modeling were used to characterize cellular differentiation, regulatory programs, and intercellular communication within the cSCC microenvironment. Results Analysis of 80,736 single cells revealed extensive heterogeneity across epithelial, immune, and stromal compartments. Trajectory analysis of the myeloid lineage suggested a tumor-associated differentiation continuum extending from circulating monocytes toward a specialized angiogenic macrophage state characterized by transcriptional programs associated with extracellular matrix remodeling and immunoregulatory signaling. Concurrently, malignant keratinocyte populations displayed inferred copy-number alterations and activation of invasive transcriptional programs, accompanied by the emergence of distinct cancer-associated fibroblast subsets associated with stromal remodeling. Ligand–receptor modeling further identified extensive predicted communication networks linking macrophages, fibroblasts, and malignant epithelial cells within the tumor niche. Furthermore, transcription factor activity inference highlighted the nuclear receptor NR1H3 as a candidate regulator associated with the angiogenic macrophage program, and the NR1H3-associated transcriptional signature correlated with poor survival across multiple squamous cell carcinoma cohorts. Discussion These findings define the cellular organization and molecular programs that shape the cSCC microenvironment and provide insights into the coordinated immune, stromal, and epithelial interactions involved in cSCC progression.
Yong He, Ting Tian, Liming Li et al.· Frontiers in Immunology· 0 citations