From embryogenesis to aging, billions of cells perish daily in mammals. The multistep process by which phagocytes engulf these deceased cells without eliciting an inflammatory response is called efferocytosis. Despite significant insights into the fundamental mechanisms of efferocytosis, its implications in disorders such as aging and cancer remain elusive. Upon summarizing and analyzing existing studies on efferocytosis, it becomes evident that efferocytosis is our friend in resolving inflammation, yet it transforms into our foe by facilitating tumor development and metastasis. This review illuminates recent discoveries regarding the emerging mechanisms of efferocytosis in clearing apoptotic cells, explores its connections with aging, examines its influence on tumor development and metastasis, and identifies the regulatory factors of efferocytosis within the tumor microenvironment. A comprehensive understanding of these efferocytosis facets offers insights into crucial physiological and pathophysiological processes, paving the way for innovative therapeutic approaches to combat aging and cancer.

Hypoxia in the tumor microenvironment promotes lymphatic metastasis, yet the role of cancer-associated fibroblasts (CAFs) in this process remains insufficiently elucidated in colorectal cancer (CRC). In this study, we developed a large language model–based cellular hypoxia–predicting classifier to identify hypoxic CAFs (HCAFs) at single-cell resolution. Our findings revealed that HCAFs enhance CRC lymphatic metastasis by secreting CLEC11A, a protein that binds to the LGR5 receptor on tumor cells, subsequently activating the WNT/β-catenin signaling pathway. This promotes epithelial-mesenchymal transition and lymphangiogenesis, facilitating the spread of tumor cells via the lymphatic system. Furthermore, we demonstrate that the hypoxia-induced transcription factor HIF1A regulates the conversion of normoxic CAFs to HCAFs, driving CLEC11A expression and promoting metastasis. In vivo and vitro experiments confirmed the pro-metastatic role of CLEC11A in CRC, with its inhibition reducing lymphatic metastasis. This effect was markedly reversed by targeting the LGR5 receptor on tumor cells or inhibiting the WNT/β-catenin pathway, further elucidating the underlying mechanisms of CLEC11A-driven metastasis. These findings underscore the potential of targeting the CLEC11A-LGR5 axis to prevent lymphatic dissemination in CRC. Our study highlights the role of HCAFs in CRC progression and reveals mechanisms of lymphatic metastasis for intervention.

Tumor-associated stromal cells (TASCs) are key architects of the tumor microenvironment (TME), playing a vital role in tumor development, metastasis, and therapeutic response. Their spatiotemporal heterogeneity, characterized by dynamic phenotypic plasticity, diverse cellular subtypes, and distinct spatial distributions, offers profound insights into tumor behavior and paves the way for innovative therapy development. In particular, stromal–immune interactions reveal the powerful capacity of TASCs to shape the immune landscape, highlighting their potential as targets in immunotherapy. Despite growing evidence in functional diversity, precise mechanisms underlying the temporal evolution and spatial organization of TASCs remain elusive, impeding clinical translation. This review delved into the molecular signatures and functional states of TASCs, emphasizing their roles in tumor dynamics and therapeutic resistance. We also discussed innovative strategies targeting the plasticity of TASCs to reverse immune evasion and potentiate immune-mediated tumor eradication. Future studies should prioritize identifying spatially resolved and mechanically defined biomarkers with multi-omics and machine learning approaches, enabling a comprehensive understanding of TASCs to bridge the gap from bench to bedside.