Publications by Cathrin Brisken

Targeting the Progesterone Receptor in Breast Cancer: Mind the Short Form!

Cathrin Brisken, Carlos Henrique Venturi Ronchi

The presurgical window of opportunity trial (WOT) MIPRA provides evidence that neoadjuvant treatment with the prog-esterone receptor (PR) antagonist mifepristone (RU486) may benefit patients with estrogen receptor-positive (ER+) breast cancer characterized by a high ratio of PR-A versus PR-B iso-form (>1.5), suggesting that PR may be targeted in a subset of patients. See related article by Elia et al., p. 866

AMER ASSOC CANCER RESEARCH2023

TGF beta-mediated MMP13 secretion drives myoepithelial cell dependent breast cancer progression

Andrea Agnoletto, Cathrin Brisken

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer. Virtually all women with DCIS are treated, despite evidence suggesting up to half would remain with stable, non-threatening, disease. Overtreatment thus presents a pressing issue in DCIS management. To understand the role of the normally tumour suppressive myoepithelial cell in disease progression we present a 3D in vitro model incorporating both luminal and myoepithelial cells in physiomimetic conditions. We demonstrate that DCIS-associated myoepithelial cells promote striking myoepithelial-led invasion of luminal cells, mediated by the collagenase MMP13 through a non-canonical TGF beta - EP300 pathway. In vivo, MMP13 expression is associated with stromal invasion in a murine model of DCIS progression and is elevated in myoepithelial cells of clinical high-grade DCIS cases. Our data identify a key role for myoepithelial-derived MMP13 in facilitating DCIS progression and point the way towards a robust marker for risk stratification in DCIS patients.

NATURE PORTFOLIO2023

Epithelial-mesenchymal plasticity determines estrogen receptor positive breast cancer dormancy and epithelial reconversion drives recurrence

Giovanna Ambrosini, Patrik Aouad, Cathrin Brisken, Fabio De Martino, Kelly Spry Maggs, Hazel Margaret Quinn, Georgios Sflomos, Céline Marie Victoria Stibolt, Yueyun Zhang

More than 70% of human breast cancers (BCs) are estrogen receptor α-positive (ER+). A clinical challenge of ER+ BC is that they can recur decades after initial treatments. Mechanisms governing latent disease remain elusive due to lack of adequate in vivo models. We compare intraductal xenografts of ER+ and triple-negative (TN) BC cells and demonstrate that disseminated TNBC cells proliferate similarly as TNBC cells at the primary site whereas disseminated ER+ BC cells proliferate slower, they decrease CDH1 and increase ZEB1,2 expressions, and exhibit characteristics of epithelial-mesenchymal plasticity (EMP) and dormancy. Forced E-cadherin expression overcomes ER+ BC dormancy. Cytokine signalings are enriched in more active versus inactive disseminated tumour cells, suggesting microenvironmental triggers for awakening. We conclude that intraductal xenografts model ER + BC dormancy and reveal that EMP is essential for the generation of a dormant cell state and that targeting exit from EMP has therapeutic potential.

2022

RNA sequencing-based single sample predictors of molecular subtype and risk of recurrence for clinical assessment of early-stage breast cancer

Ayyakkannu Ayyanan, Cathrin Brisken, Rachel Marcone

Multigene assays for molecular subtypes and biomarkers can aid management of early invasive breast cancer. Using RNA-sequencing we aimed to develop single-sample predictor (SSP) models for clinical markers, subtypes, and risk of recurrence (ROR). A cohort of 7743 patients was divided into training and test set. We trained SSPs for subtypes and ROR assigned by nearest-centroid (NC) methods and SSPs for biomarkers from histopathology. Classifications were compared with Prosigna in two external cohorts (ABiM, n = 100 and OSLO2-EMIT0, n = 103). Prognostic value was assessed using distant recurrence-free interval. Agreement between SSP and NC for PAM50 {five subtypes) was high (85%, Kappa = 0.78) for Subtype (four subtypes) very high {90%, Kappa = 0.84) and for ROR risk category high (84%, Kappa = 0.75, weighted Kappa = 0.90). Prognostic value was assessed as equivalent and clinically relevant. Agreement with histopathology was very high or high for receptor status, while moderate for Ki67 status and poor for Nottingham histological grade. SSP and Prosigna concordance was high for subtype (OSLO-EMIT0 83%, Kappa = 0.73 and ABiM 80%, Kappa = 0.72) and moderate and high for ROR risk category (68 and 84%, Kappa = 0.50 and 0.70, weighted Kappa = 0.70 and 0.78). Pooled concordance for emulated treatment recommendation dichotomized for chemotherapy was high (85%, Kappa = 0.66). Retrospective evaluation suggested that SSP application could change chemotherapy recommendations for up to 17% of postmenopausal ER+/HER2-/N0 patients with balanced escalation and de-escalation. Results suggest that NC and SSP models are interchangeable on a group-level and nearly so on a patient level and that SSP models can be derived to closely match clinical tests.

NATURE PORTFOLIO2022

Deep Learning Enables Individual Xenograft Cell Classification in Histological Images by Analysis of Contextual Features

Cathrin Brisken, Olivier Burri, Fabio De Martino, Quentin Juppet, Daniel Sage, Michaël Unser, Martin Weigert

Patient-Derived Xenografts (PDXs) are the preclinical models which best recapitulate inter- and intra-patient complexity of human breast malignancies, and are also emerging as useful tools to study the normal breast epithelium. However, data analysis generated with such models is often confounded by the presence of host cells and can give rise to data misinterpretation. For instance, it is important to discriminate between xenografted and host cells in histological sections prior to performing immunostainings. We developed Single Cell Classifier (SCC), a data-driven deep learning-based computational tool that provides an innovative approach for automated cell species discrimination based on a multi-step process entailing nuclei segmentation and single cell classification. We show that human and murine cell contextual features, more than cell-intrinsic ones, can be exploited to discriminate between cell species in both normal and malignant tissues, yielding up to 96% classification accuracy. SCC will facilitate the interpretation of H&E- and DAPI-stained histological sections of xenografted human-in-mouse tissues and it is open to new in-house built models for further applications. SCC is released as an open-source plugin in ImageJ/Fiji available at the following link: https://github.com/Biomedical-Imaging-Group/SingleCellClassifier.

2021

Intraductal xenografts show lobular carcinoma cells rely on their own extracellular matrix and LOXL1

Giovanna Ambrosini, Patrik Aouad, Ayyakkannu Ayyanan, Laura Battista, Cathrin Brisken, Philipp Bucher, Fabio De Martino, Maryse Fiche, Valentina Scabia, Georgios Sflomos

Invasive lobular carcinoma (ILC) is the most frequent special histological subtype of breast cancer, typically characterized by loss of E‐cadherin. It has clinical features distinct from other estrogen receptor‐positive (ER+) breast cancers but the molecular mechanisms underlying its characteristic biology are poorly understood because we lack experimental models to study them. Here, we recapitulate the human disease, including its metastatic pattern, by grafting ILC‐derived breast cancer cell lines, SUM‐44 PE and MDA‐MB‐134‐VI cells, into the mouse milk ducts. Using patient‐derived intraductal xenografts from lobular and non‐lobular ER+ HER2− tumors to compare global gene expression, we identify extracellular matrix modulation as a lobular carcinoma cell‐intrinsic trait. Analysis of TCGA patient datasets shows matrisome signature is enriched in lobular carcinomas with overexpression of elastin, collagens, and the collagen modifying enzyme LOXL1. Treatment with the pan LOX inhibitor BAPN and silencing of LOXL1 expression decrease tumor growth, invasion, and metastasis by disrupting ECM structure resulting in decreased ER signaling. We conclude that LOXL1 inhibition is a promising therapeutic strategy for ILC.

2021

90 YEARS OF PROGESTERONE Progesterone receptor signaling in the normal breast and its implications for cancer

Cathrin Brisken, Valentina Scabia

Progesterone is considered as the pregnancy hormone and acts on many different target tissues. Progesterone receptor (PR) signaling is important for normal development and the physiologic function of the breast and impinges on breast carcinogenesis. Both systemically and locally, in the breast epithelium, there are multiple layers of complexity to progesterone action, many of which have been revealed through experiments in mice. The hormone acts via its receptor expressed in a subset of cells, the sensor cells, in the breast epithelium with different signaling outcomes in individual cells eliciting distinct cell-intrinsic and paracrine signaling involving different mediators for different intercellular interactions. PR expression itself is developmentally regulated and the biological outcome of PR signaling depends on the developmental stage of the mammary gland and the endocrine context. During both puberty and adulthood PR activates stem and progenitor cells through Wnt4-driven activation of the myoepithelium with downstream Adamts18-induced changes in extracellualr matrix (ECM) / basal membrane (BM). During estrous cycling and pregnancy, the hormone drives a major cell expansion through Rankl. At all stages, PR signaling is closely tied to estrogen receptor a (ER) signaling. As the PR itself is a target gene of ER, the complex interactions are experimentally difficult to dissect and still poorly understood. Ex vivo models of the human breast and studies on biopsy samples show that major signaling axes are conserved across species. New intraductal xenograft models hold promise to provide a better understanding of PR signaling in the normal breast epithelium and in breast cancer development in the near future.

BIOSCIENTIFICA LTD2020

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Background Estrogen receptor alpha (ER alpha) signaling is a defining and driving event in most breast cancers; ER alpha is detected in malignant epithelial cells of 75% of all breast cancers (classified as ER-positive breast cancer) and, in these cases, ER alpha targeting is the main therapeutic strategy. However, the biological determinants of ER alpha heterogeneity and the mechanisms underlying therapeutic resistance are still elusive, hampered by the challenges in developing experimental models recapitulative of intra-tumoral heterogeneity and in which ER alpha signaling is sustained. Ex vivo cultures of human breast cancer tissue have been proposed to retain the original tissue architecture, epithelial and stromal cell components and ER alpha. However, loss of cellularity, viability and ER alpha expression are well-known culture-related phenomena. Methods BC samples were collected and brought to the laboratory. Then they were minced, enzymatically digested, entrapped in alginate and cultured for 1 month. The histological architecture, cellular composition and cell proliferation of tissue microstructures were assessed by immunohistochemistry. Cell viability was assessed by measurement of cell metabolic activity and histological evaluation. The presence of ER alpha was accessed by immunohistochemistry and RT-qPCR and its functionality evaluated by challenge with 17-beta-estradiol and fulvestrant. Results We describe a strategy based on entrapment of breast cancer tissue microstructures in alginate capsules and their long-term culture under agitation, successfully applied to tissue obtained from 63 breast cancer patients. After 1 month in culture, the architectural features of the encapsulated tissue microstructures were similar to the original patient tumors: epithelial, stromal and endothelial compartments were maintained, with an average of 97% of cell viability compared to day 0. In ER alpha-positive cases, fibers of collagen, the main extracellular matrix component in vivo, were preserved. ER alpha expression was at least partially retained at gene and protein levels and response to ER alpha stimulation and inhibition was observed at the level of downstream targets, demonstrating active ER signaling. Conclusions The proposed model system is a new methodology to study ex vivo breast cancer biology, in particular ER alpha signaling. It is suitable for interrogating the long-term effects of anti-endocrine drugs in a set-up that closely resembles the original tumor microenvironment, with potential application in pre- and co-clinical assays of ER alpha-positive breast cancer.

2020

Characterization of circulating breast cancer cells with tumorigenic and metastatic capacity

Laura Battista, Cathrin Brisken, Georgios Sflomos

Functional studies giving insight into the biology of circulating tumor cells (CTCs) remain scarce due to the low frequency ofCTCs and lack of appropriate models. Here, we describe the characterization of a novelCTC-derived breast cancer cell line, designatedCTC-ITB-01, established from a patient with metastatic estrogen receptor-positive (ER+) breast cancer, resistant to endocrine therapy.CTC-ITB-01 remainedER(+)in culture, and copy number alteration (CNA) profiling showed high concordance betweenCTC-ITB-01 andCTCs originally present in the patient with cancer at the time point of blood draw.RNA-sequencing data indicate thatCTC-ITB-01 has a predominantly epithelial expression signature. Primary tumor and metastasis formation in an intraductalPDXmouse model mirrored the clinical progression ofER(+)breast cancer. DownstreamERsignaling was constitutively active inCTC-ITB-01 independent of ligand availability, and theCDK4/6 inhibitor Palbociclib strongly inhibitedCTC-ITB-01 growth. Thus, we established a functional model that opens a new avenue to studyCTCbiology.

WILEY2020

IL6/STAT3 Signaling Hijacks Estrogen Receptor α Enhancers to Drive Breast Cancer Metastasis

Cathrin Brisken, Sanjeev Kumar, Valentina Scabia

2020