Search bioRxiv⌕ Search

bioRxiv · 10.1101/2025.04.04.647210

Proteostasis control via HSP90α sustains YAP activity to drive aggressive behaviours in cancer-associated fibroblasts

Abstract

Cancers adapt proteostasis to cope with the burden of misfolded proteins, stabilize key signalling nodes and sustain their malignant behaviour. Tumour stroma is subjected to similar stresses, but how they influence its aberrant status remains unclear. We show that tumour stroma presents consistent upregulation of target genes associated to the major misfolding regulator HSP90 in cancer-associated fibroblasts (CAFs), and that HSP90 is required for CAFs to remodel the extracellular matrix (ECM) and promote cancer cell motility and growth. Mechanistically, HSP90 sustains TGF{beta} responses and YAP protein levels required for CAF functionality. In vivo, stromal or fibroblast-specific loss of HSP90 results in reduced ECM deposition, angiogenesis, growth and dissemination of breast tumours. Clinical analyses reveal a correlation between HSP90-dependent programs and YAP activity in CAFs, that are also associated with poor patient prognosis. Our findings uncover a link between proteostasis, mechanotransduction and generation of aggressive tumour microenvironments through HSP90.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Dominguez-Garcia, S., Rodriguez, J., Julia, M., Coursier, D., Perez-Lopez, C., Carnicero, P., Villar, A. V., von Kriegsheim, A., Calvo, F.. 2025-04-09. Proteostasis control via HSP90α sustains YAP activity to drive aggressive behaviours in cancer-associated fibroblasts. https://doi.org/10.1101/2025.04.04.647210

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Tet2-Clonal Hematopoiesis Promotes Whereas Dnmt3a-CH Inhibits Breast Cancer Progression During Aging

Clonal hematopoiesis of indeterminate potential (CHIP) driven by somatic mutations in blood cells increases with age and is associated with adverse outcomes in cancer patients. How CHIP mutations influence solid tumor progression remains unclear. Using inducible murine models of Dnmt3a- or Tet2-mutant CHIP combined with orthotopic syngeneic breast cancer models, we demonstrate that upon aging Dnmt3a-mutant CHIP prevents whereas Tet2-mutant CHIP drives breast cancer progression. Dnmt3a-mutant immune infiltrates established interferon-mediated MHCIIhigh tumor-associated macrophages (TAMs) that supported cytotoxic CD8+ T cell-mediated tumor rejection. In contrast, Tet2-mutant TAMs exhibited an inflammatory, immunosuppressive phenotype characterized by increased IL-1 and CXCL2 production, reduced MHCII expression, and impaired T cell recruitment and activation. Therapeutic blockade of IL-1R1 or CXCR2 reduced tumor progression in aged Tet2-mutant CHIP mice and partially restored anti-tumor immunity. These findings establish that the effects of CHIP on cancer are mutation- and age-dependent and identify IL-1/CXCL2-driven inflammation as a therapeutic vulnerability of tumor-promoting Tet2-mutant CHIP.

cancer biology↗

Single Nucleus Profiling Reveals Rewired Tumor-Immune-Stromal Cell Communication in Plasmacytoid Urothelial Carcinoma

Plasmacytoid urothelial carcinoma (PUC) is an aggressive histologic subtype of bladder cancer associated with worse patient outcomes and therapeutic response compared to conventional urothelial carcinoma (CUC). While recent work has demonstrated metastatic lymph nodes from PUC tumors have an inflamed phenotype, how the tumor microenvironment (TME) and crosstalk between tumor, stromal, and immune cells in primary PUC bladder tumors differs from those in CUC remains poorly understood. The impact of these differences on response to immunotherapy is also unknown. To understand TME differences between CUC and PUC and their impact on cell signaling, we performed single nucleus RNA sequencing on PUC and CUC tumors, as well as Xenium spatial transcriptomics on a mixed CUC / PUC tumor. We identified increased signaling between PUC-enriched, CDH1-low urothelial cells, immunosuppressive lipid-associated macrophages, and SFRP2+/CTHRC1+ fibroblasts in PUC tumors compared to CUC. Spatial transcriptomics identified increased macrophage infiltration in PUC histology and colocalization of PUC tumor cells, immunosuppressive macrophages, and SFRP2+ fibroblasts. Taken together, this study delineates PUC architecture and demonstrates interplay CDH1-low tumor cells, EMT, and immunosuppressive macrophages, identifying possible therapeutic vulnerabilities in PUC.

cancer biology↗

The Phospholipase A2 Activity of Peroxiredoxin 6 Protects Hepatocarcinoma Cells Against Ferroptosis and Mitophagy Impairment

Peroxiredoxin 6 (PRDX6) is a moonlighting protein that plays a key role in regulating redox homeostasis and lipid metabolism through its unique dual peroxidase and calcium-independent phospholipase A2 (iPLA2) activities. Here, we generated a stable HepG2 cell line harboring a D140A mutation to selectively ablate iPLA2 activity, and we compared its phenotype with that of wild-type (WT) and PRDX6-knockout (KO) cells. D140A exhibited low ROS leves, similar to WT cells, confirming that oxidative stress is due to peroxidase deficiency. In contrast, D140A cells displayed higher lipid peroxidation than WT cells, though significantly lower than that of KO cells. Furthermore, the D140A mutant mirrored the KO phenotype regarding intracellular ferrous iron accumulation, impaired lipid droplet biogenesis, and the downregulation of the key ferroptosis regulator GPX4. Mechanistically, integrated proteomic, lipidomic, and enzymatic analyses revealed that a deficiency in iPLA2 activity of PRDX6 disrupted the release of key lipid species necessary for cell structure and signaling. Consequently, organelles involved in lipid synthesis and trafficking, such as peroxisomes, endoplasmic reticulum, mitochondria and lipid droplet, were affected. Specifically, we found that mitochondria exhibited a reduction in cristae and a diminished capacity for mitophagy and autophagy, which ultimately makes cells much more susceptible to erastin-induced ferroptotic cell death. Taken together, our findings demonstrate that PRDX6 iPLA2 activity uniquely coordinates organelle lipid homeostasis and mitophagy to protect cancer cells from ferroptotic cell death. Consequently, the use of iPLA2 inhibitors such as MJ33, which decreased PRDX6 iPLA2 activity to a level comparable to the mutant D140A, could represent a promising therapeutic strategy for inducing ferroptotic cell death in hepatocellular carcinoma.

cancer biology↗