It is demonstrated that cancer stem cells are hyper-responsive to microenvironmental cues, which they sense and adapt to through YAP/TAZ signalling, thereby playing an essential role in breast cancer lung metastasis.
Abstract
Cancer stem cells (CSCs) drive metastasis and therapy resistance, yet their behaviour within the complex tumour microenvironment remains poorly understood. Here we use a fluorescent reporter that marks CSCs to show that CSCs and their more differentiated progeny display strikingly different population dynamics during metastatic lung colonization in breast cancer models. CSC expansion is rapidly curtailed early in colonization, suggesting a strong negative feedback mechanism acting selectively on this subpopulation. We showed that CSCs are exceptionally sensitive to local microenvironmental cues such as cell crowding and nutrient availability. They respond earlier and more extensively than their differentiated progeny, thereby coupling tumour growth to resource and space availability. Microenvironmental signals converge on the transcriptional regulatory complex YAP/TAZ/TEAD, with CSC sensitivity arising from elevated signal reception and greater chromatin accessibility at TEAD-regulated enhancers. Targeting upstream inputs to this pathway reversed chemotherapy-induced CSC enrichment in lung metastases, suggesting a potential therapeutic strategy. Using a dynamic fluorescent reporter, Tang et al. demonstrate that cancer stem cells are hyper-responsive to microenvironmental cues, which they sense and adapt to through YAP/TAZ signalling, thereby playing an essential role in breast cancer lung metastasis.
Cancer therapy has advanced substantially through targeted therapies and immunotherapy; however, durable clinical responses remain limited by the development of drug resistance. Increasing evidence identifies cancer stem cells (CSCs) as central drivers of therapeutic failure, tumor recurrence, metastasis, and minimal residual disease. CSCs possess self-renewal and differentiation capacities together with remarkable adaptability under therapeutic stress, enabling long-term tumor maintenance and regeneration. CSC-mediated resistance arises through coordinated intrinsic and extrinsic mechanisms. Intrinsically, CSCs employ multiple survival programs, including cellular quiescence, enhanced DNA damage response and repair, ATP-binding cassette transporter-mediated drug efflux, apoptosis evasion, and metabolic reprogramming. Extrinsically, these mechanisms are reinforced through dynamic interactions with the tumor microenvironment (TME), particularly hypoxic and perivascular niches that support stemness and therapeutic tolerance. Importantly, CSCs are increasingly recognized as dynamic cellular states rather than fixed populations and exhibit marked plasticity through reversible transitions between stem-like and non-stem states, frequently mediated by epithelial–mesenchymal transition (EMT). This plasticity promotes intratumoral heterogeneity and replenishes resistant cell populations. In this review, we provide a comprehensive synthesis of the molecular and microenvironmental mechanisms underlying CSC-driven drug resistance and critically discuss emerging therapeutic strategies targeting CSC plasticity, niche interactions, metabolic adaptation, and immune evasion. Collectively, these insights support the development of integrated multi-target therapeutic approaches to improve long-term clinical outcomes.
Hayam Hamdy, Youzhou Li, Chen Li et al.· Molecular Biomedicine· 0 citations
Breast cancer remains the most prevalent malignancy among women worldwide, with approximately 2.3 million new cases diagnosed annually, accounting for nearly 12% of all cancer diagnosis globally. Increasing evidence highlights the tumor microenvironment (TME) as a dynamic and interactive ecosystem that governs tumor behaviour. This review consolidates emerging evidence that positions cell competition as a critical regulator of clonal dynamics within the breast cancer TME. We examine how breast cancer stem cells (BCSCs), defined by CD44+/CD24- phenotype and elevated ALDH activity, acquire enhanced fitness through MYC amplification and dysregulation of Hippo/YAP, Wnt/β-catenin and Notch signaling pathways. In parallel, we analyze the role of immune cell populations including tumor-associated macrophages, cytotoxic T lymphocytes, natural killer cells and myeloid-derived suppressor cells in shaping competitive interactions through resource limitation and immuno-suppressive signaling. We further explore metabolic competition, highlighting the Warburg effect, reverse Warburg effect and lactate-mediated immuno-suppression as central regulators of cellular fitness, alongside contributions from cancer-associated fibroblasts, extracellular matrix remodeling and exosome-mediated communication. The novelty of this study lies in integrating cellular, metabolic and stromal dimensions of competition into a unified framework and extending the concept beyond tumor cells to include immune and non-cellular components. Cumulatively, this study identifies competitive cellular fitness as a central and targetable driver of therapeutic resistance and tumor recurrence in breast cancer.
Esha Pal, Sovan Chakraborty, A. Guha· Frontiers in Oncology· 0 citations
Tumor plasticity and microenvironmental heterogeneity are established as an integrated, evolving system that fuels metastasis and limits durable treatment responses.
G. Dagar, M. Dagar, Ashna Gupta et al.· MedComm· 0 citations
Cancer stem cells (CSCs) are tumor cell subsets with self-renewal, multilineage differentiation, and tumor-initiating capacity that sustain cancer initiation, progression, metastasis, and relapse. Targeting CSCs therefore represents a promising route to improve the durability of cancer treatment. However, translation of this approach into routine care has been slow because of the biological complexity and clinical constraints. This review discusses current concepts of CSC origin and plasticity, the criteria used to define CSCs across different tumor types, and the marker systems as well as high-resolution technologies that are used to track CSC states. Developmental pathways, growth factor and cytokine cascades, as well as microenvironmental and stress responses that control CSC maintenance and therapy resistance are explored with a focus on their tractability as drug targets. We then discuss mechanisms through which CSCs escape chemotherapy, radiotherapy, and targeted agents. We review current efforts to use these pathways in designing small molecules, antibodies, cellular therapies, and vaccines aimed at CSC compartments. Heterogeneity within and between tumors, dynamic interconversion between CSC and non-CSC states, and support from specialized niches are considered as major barriers for clinical trial design, biomarker development, and response assessment. Emerging single-cell, spatial, and lineage tracing approaches, together with organoid and ex vivo platforms, are reviewed as tools that can bridge preclinical models and patient samples and guide the development of CSC-directed combination regimens. The goal is to outline translational principles that can guide future strategies for integrating CSC-focused interventions with established therapies to improve long-term disease control.
Mehreen Ahmed, A. Al-haidari, S. Agarwal et al.· Signal Transduction and Targ...· 0 citations
Cancer stem cells (CSCs) represent functionally defined and phenotypically plastic tumor cell populations implicated in therapeutic resistance, relapse, and metastasis. CSC plasticity is regulated through coordinated stemness signaling and epigenetic mechanisms. Canonical stemness-associated pathways, including Wnt, Notch, and Hedgehog, interact with epigenetic programs to maintain dynamic stem-like states and facilitate cellular adaptation to environmental and therapeutic stress. These regulatory networks are also associated with metabolic reprogramming and may support CSC survival under therapeutic and immune pressure. This review summarizes recent advances in our understanding of CSC plasticity, with a particular focus on the bidirectional interplay between CSCs and the tumor immune microenvironment. From a translational perspective, it further summarizes emerging strategies for targeting CSC plasticity in combination with immunotherapy, and discusses the present limitations and challenges of combination strategies. These observations may provide a conceptual framework for the development of more rational combination strategies, although their clinical benefit remains to be validated.
Jingyu Tan, Tao Wen, Jian Liu et al.· Journal of Hematology & Onco...· 0 citations
The mechanisms underlying the interactions between disseminated tumor cells (DTCs) and their tissue microenvironment during metastatic colonization are currently poorly understood. We integrated multimodal single-cell and spatial profiling from liver cancer mouse models and human metastases to track the spatiotemporal dynamics of DTCs and their microenvironments from single-cell seeding to overt lung metastasis. We identified a residual population of quiescent Phgdhhigh DTCs that survived initial innate immune clearance and became transiently enriched in micrometastases. These cells shaped an immune-scarce microenvironment through PHGDH-dependent, H3K27me3-mediated epigenetic silencing of chemokine transcription, thereby promoting metastatic expansion. Cx3cr1high interstitial macrophages were also transiently enriched before DTC expansion, creating an immune-privileged niche for metastatic outgrowth by recruiting immunosuppressive cells. Inactivating the PHGDH-H3K27me3 axis in DTCs or depleting interstitial macrophages restored immune surveillance and inhibited metastatic colonization. These findings provide insights into the development of micrometastasis-targeting regimens.
Yunfan Sun, Y. Zhong, Shang Liu et al.· Science· 0 citations