*The implications*
These results position CAF niches—not just CAF types—as actionable units. Precision targeting of CAF-defined functional niches may rewire tumor–immune interactions and enhance therapeutic responses in breast cancer.
*The novelty*
Spatial context matters: immunomodulatory CAFs co-localize with immune cells, whereas myofibroblastic CAFs form a barrier around the tumor core, limiting immune infiltration. CAF transcriptional programs are shaped by their local cellular neighborhoods.
*The findings*
By integrating scRNA-seq, multiplex immunostaining, and spatial analysis in murine and human breast tumors, we identified six CAF substates that occupy distinct, stage-dependent spatial niches within tumors.
*The scene*
Cancer-associated fibroblasts (CAFs) are major architects of the breast cancer microenvironment, yet how CAF heterogeneity emerges over time and space during tumor progression has remained unclear.
Starting 2026 in style 🕺💃! New paper out from talented PhD-student @jessicapantaleo.bsky.social who conceptualized the breast tumor microenvironment to visualize architectural structure in cancer-associated fibroblast niches. Thanks to all funders and collaborators😇
link.springer.com/article/10.1...
Check this out👇
Our neighbors @pietraslab.bsky.social has just published a new preprint detailing high-resolution profiling of the irradiated GBM microenvironment. ❄️Cool reading for the holidays❄️ Thanks for including us!
Thanks for inspiring collaborations with @pietraslab.bsky.social @jonssonmelanomalab.bsky.social
We are grateful for generous support from @vetenskapsradet.bsky.social #Barncancerfonden #Cancerfonden #L2CancerBridge
7/ Therapeutic & translational implications
Strategies that preserve pericyte function might reinforce vascular and immune barriers against GBM progression.
Conversely, therapies that inadvertently deplete pericytes might worsen disease by unleashing immuno-suppressive and invasive programs.
6/ Take-home message
Pericytes are not merely passive structural cells — in GBM, they act as central conductors of microenvironmental signaling that restrain tumor growth and invasion. Their loss rewires the vasculature + immune microenvironment, fueling aggressive mesenchymal, MET-driven GBM.
5/ Clinical relevance
In human GBM, low expression of a pericyte core gene signature was observed more often in recurrent tumors vs primary. Also, the prevalence of FOSL1⁺ GBM cells correlated with poor patient survival. Pericyte loss may thus contribute to aggressive relapse of GBM.
4/ HGF → MET activation → mesenchymal invasion
TAMs express HGF, which boosts activation of the receptor MET on GBM cells — notably in those with a mesenchymal phenotype regulated by FOSL1. Thus: loss of pericytes → vascular & immune remodeling → HGF-MET signaling → mesenchymal, invasive GBM.
3/ What happens when pericytes are lost?
Genetic depletion of pericytes in mouse GBM models dramatically accelerated tumor growth and shortened survival. Mechanistically, pericyte loss remodels the tumor vasculature, recruiting tumor-associated immunosuppressive macrophages (TAMs).
2/ Pericytes = central communication nodes
By scRNAseq + cell-cell communication inference, we found that pericytes exhibit the highest paracrine signaling activity in human high-grade glioma. Thus, pericytes are not just passive structural cells; they are active “conductors” of signaling in GBM.
1/ What’s new?
Glioblastoma (GBM) is notoriously aggressive, driven by complex crosstalk between malignant cells and their microenvironment. Our work shows that pericytes, long-viewed mainly as vascular support cells, act as a major paracrine signaling hub that restrains tumor growth.
New paper alert 🚨
We are delighted to present our latest paper in @natcomms.nature.com through fabulous work from co-first authors Sebastian Braun and Paulina Bolivar! Big thanks to all expert collaborators for taking this long journey with us!
Tweetorial in comments 🧵
www.nature.com/articles/s41...
Reflecting on the 2025 EACR Cancer Neuroscience Conference in Bilbao- what a friendly, inspiring meeting with many opportunities to increase connectivity, in that case to fight tumors. Big ‘Thank you’ to the organizers!
Don’t miss a joint LUCC-LBIC-ZEISS-ACD seminar on visualization of gene expression and biomarker localization in 2D, 3D and 4D. 16th June, BMC, Lund.
🚨 We’re hiring a bioinformatics-focused PhD student for our ERC-funded project on recurrent GBM! Focus: tumor-supportive microenvironment 🔬 Experience with scRNA-seq, spatial transcriptomics & Python/R a plus. Must be self-motivated & driven. DM for details! Repost=❤️ lu.varbi.com/en/what:job/...
Swedish Childhood Cancer Fund (BCF) is raising awareness and support: today it is #Fotbollströjefredagen (Football shirt Friday)
Join us for innovative explorations of the tumor microenvironment🔬 Learn cutting-edge technologies and grow in a dynamic environment💡 The postdoc will work alongside a doctoral student from @adaptmet.bsky.social, gaining access to collaborative partners across 🇪🇺.
Apply now👇
tinyurl.com/4mby45hf
Targeting the most immune-suppressive macrophage with ALK1 inhibitors in malignant breast cancer!
@kpietraslab.bsky.social & team @lund-university.bsky.social target the most immune-suppressive macrophage with ALK1 inhibitors in malignant breast cancer models!
buff.ly/FXssb1x
Congratulations Kristian! @lundsuniversitet.bsky.social @lunduniversity-med.bsky.social
We are proud to share that our PI has been named Cancer Researcher of the Year by @Cancerfonden! This well-deserved recognition highlights not only his outstanding contributions to cancer research but also his creativity in tackling scientific challenges and his inspiring leadership within our team.
🎉 Today, we gathered online for the #AdaptMet Kick-Off Meeting! A fantastic start to this journey, bringing together top researchers & partners to train the next generation of metastasis experts. Exciting discussions & collaborations ahead—stay tuned! 🔬✨ #CancerResearch
At the Brain Tumor Microenvironment Symposium @institutducerveau.bsky.social, Sebastian Braun presented our comprehensive study of pericytes in GBM 🤩. Pericytes act as guardians of the peri-vascular niche to prevent malignant cell invasion, read more at www.biorxiv.org/content/10.1...
@jessicapantaleo.bsky.social making us proud at the @lund-university.bsky.social Cancer Centre Tumor Microenvironment retreat by presenting our latest findings on CAF subtype spatial organization across longitudinally sampled experimental breast cancers.
Thanks @oncogenejournal for highlighting our work on cancer-associated fibroblasts that enable endocrine resistance in luminal breast cancer
www.nature.com/collections/...
