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Biology subjects

Calvo, F.

Publications and source records attributed to Calvo, F..

7 recordsLinked to original sources

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

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.

cancer biology↗

Dysregulated SASS6 expression promotes increased ciliogenesis and cell invasion phenotypes

Centriole and/or cilia defects are characteristic of cancer cells and have been linked to cancer cell invasion. However, the mechanistic basis of these effects is unknown. Spindle assembly abnormal protein 6 homolog (SAS-6) is essential for centriole biogenesis and cilia formation. In cycling cells, SAS-6 undergoes APCCdh1-mediated targeted degradation by the 26S proteasome at the end of mitosis. Little is known about the function of SAS-6 outside of centrosome biogenesis. To examine this, we expressed a non-degradable SAS-6 mutant (SAS-6ND). Expression of SAS-6ND led to an increase in ciliation and cilia-dependent cell invasion, and caused an upregulation of the YAP/TAZ pathway. YAP/TAZ or ciliogenesis inhibition prevented SAS-6-induced invasion. SAS-6ND caused increased actin alignment and stress fiber coherency, and nuclear flattening known to promote YAP nuclear import. Finally, data from The Cancer Genome Atlas showed that SAS-6 overexpression is associated with poor prognosis in various cancers. Our data provide evidence for a defined role of SAS-6 in cancer cell invasion and offers mechanistic insight into the role of YAP/TAZ in this cilia-sensitive process. Synopsis O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=157 SRC="FIGDIR/small/576599v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@1cec0daorg.highwire.dtl.DTLVardef@d73051org.highwire.dtl.DTLVardef@1a53e47org.highwire.dtl.DTLVardef@19bb05d_HPS_FORMAT_FIGEXP M_FIG C_FIG SAS-6 overexpressing cells show increased ciliation, actin cytoskeleton reorganization, cell flattening, YAP pathway activation and increased invasion

cell biology↗

Myeloid derived Oncostatin M reprogrammes cancer-associated fibroblasts and tumour cells promoting breast cancer progression

Cancer cells are constantly communicating with the surrounding tumour microenvironment (TME) and they hijack physiological cell interactions to overcome immune system surveillance and promote cancer progression1,2. However, the contribution of stromal cells to the reprogramming of the TME is not well understood. In this study we provide unprecedented evidence of the role of the cytokine Oncostatin M (OSM) as central node for multicellular interactions between immune and non-immune stroma and the epithelial compartment. We show that stromal expression of the OSM:Oncostatin M Receptor (OSMR) axis plays a key role in breast cancer progression. OSMR deletion in a multistage breast cancer model delays tumour onset, tumour growth and reduces metastatic burden. We ascribed causality to the stromal function of OSM axis by demonstrating reduced tumour burden of syngeneic tumours implanted in mice. Single-cell and bioinformatic analysis of murine and human breast tumours revealed that the expression of OSM signalling components is compartmentalized in the tumour stroma. OSM expression is restricted to myeloid cells, whereas OSMR expression is detected predominantly in fibroblasts and, to a lower extent, cancer cells. Myeloid-derived OSM reprograms fibroblasts to a more contractile and pro-tumorigenic phenotype, elicits the secretion of VEGF and pro-inflammatory chemokines (e.g. CXCL1 and CXCL16), leading to increased neutrophil and macrophage recruitment. In summary, our work sheds light on the mechanism of immune regulation by the tumour microenvironment, and supports that targeting OSM:OSMR interactions is a potential therapeutic strategy to inhibit tumour-promoting inflammation and breast cancer progression.

cancer biology↗

A mouse SWATH-MS reference spectral library enables deconvolution of species-specific proteomic alterations in human tumour xenografts

SWATH-mass spectrometry (MS) enables accurate and reproducible proteomic profiling in multiple model organisms including the mouse. Here we present a comprehensive mouse reference spectral library (MouseRefSWATH) that permits quantification of up to 10,597 proteins (62.2% of the mouse proteome) by SWATH-MS. We exploit MouseRefSWATH to develop an analytical pipeline for species-specific deconvolution of proteomic alterations in human tumour xenografts (XenoSWATH). This method overcomes the challenge of high sequence similarity between mouse and human proteins, facilitating the study of host microenvironment-tumour interactions from bulk tumour measurements. We apply the XenoSWATH pipeline to characterise an intraductal xenograft model of breast ductal carcinoma in-situ and uncover complex regulation of cell migration pathways that are not restricted to tumour cells but also operate in the mouse stroma upon progression to invasive disease. MouseRefSWATH and XenoSWATH opens new opportunities for in-depth and reproducible proteomic assessment to address wide-ranging biological questions involving this important model organism.

biochemistry↗

Cdc42EP5/BORG3 coordinates septin and actin networks to promote actomyosin function and melanoma invasion and metastasis

Fast amoeboid migration in the invasive fronts of melanoma is controlled by high levels of actomyosin contractility, which underlie its highly metastatic potential. How this migratory behaviour is coupled to other cytoskeletal components is poorly understood. Septins are increasingly recognized as novel cytoskeletal components, but details on their regulation and contribution to cancer migration and metastasis are lacking. Here, we show that the septin regulator Cdc42EP5 is consistently required for melanoma cells to migrate and invade into collagen-rich matrices, and to locally invade and disseminate in vivo. Cdc42EP5 associates with actin structures leading to increased actomyosin contractility and amoeboid migration. Cdc42EP5 effects these functions through SEPT9-dependent F-actin crosslinking, which enables the generation of F-actin bundles required for the sustained stabilisation of highly contractile actomyosin structures. This study provides evidence for Cdc42EP5 as a regulator of cancer cell motility that coordinates actin and septin networks. It also describes a unique role for SEPT9 in invasion and metastasis, and illustrates a mechanism that regulates its function in melanoma.

cancer biology↗

Genomic and transcriptomic determinants of therapy resistance and immune landscape evolution during anti-EGFR treatment in colorectal cancer

Anti-epidermal growth factor receptor (EGFR) antibodies (anti-EGFR-Ab) are effective in a subgroup of patients with metastatic colorectal cancer (CRC). We applied genomic and transcriptomic analyses to biopsies from 35 RAS wild-type CRCs treated with the anti-EGFR-Ab cetuximab in a prospective trial to interrogate the molecular resistance landscape. This validated transcriptomic CRC-subtypes as predictors of cetuximab benefit; identified novel associations of NF1-inactivation and non-canonical RAS/RAF-aberrations with primary progression; and of FGF10- and non-canonical BRAF-aberrations with AR. No genetic resistance drivers were detected in 64% of AR biopsies. The majority of these had switched from the cetuximab-sensitive CMS2-subtype pretreatment to the fibroblast- and growth factor-rich CMS4-subtype at progression. Fibroblast supernatant conferred cetuximab resistance in vitro, together supporting subtype-switching as a novel mechanism of AR. Cytotoxic immune infiltrates and immune-checkpoint expression increased following cetuximab responses, potentially providing opportunities to treat CRCs with molecularly heterogeneous AR with immunotherapy.

cancer biology↗

SREBP1 drives KRT80-dependent cytoskeletal changes and invasive behavior in endocrine resistant ERα breast cancer

Approximately 30% of women diagnosed with ER breast cancer relapse with metastatic disease following adjuvant treatment with endocrine therapies1,2. The connection between acquisition of drug resistance and invasive potential is poorly understood. In this study, we demonstrate that the type II keratin topological associating domain (TAD)3 undergoes epigenetic reprogramming in cells that develop resistance to aromatase inhibitors (AI), leading to keratin 80 (KRT80) upregulation. In agreement, an increased number of KRT80-positive cells are observed at relapse in vivo while KRT80 expression associates with poor outcome using several clinical endpoints. KRT80 expression is driven by de novo enhancer activation by sterol regulatory element-binding protein 14 (SREBP1). KRT80 upregulation directly promotes cytoskeletal rearrangements at the leading edge, increased focal adhesion maturation and cellular stiffening, which collectively promote cancer cell invasion. Shear-wave elasticity imaging of prospective patients shows that KRT80 levels correlate with stiffer tumors in vivo. Collectively, our data uncover an unpredicted and potentially targetable direct link between epigenetic and cytoskeletal reprogramming promoting cell invasion in response to chronic AI treatment.

cancer biology↗