Fabio De Martino

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

Role of the androgen receptor in the human breast epithelium

Fabio De Martino

Breast cancer is the most common malignancy in women worldwide and understanding the risk factors affecting it is key for prevention. The relative risk of developing breast cancer is related to exposure to both endogenous hormones and exogenous natural and synthetic steroid hormone receptor agonists. Hormonal contraception exposes million of women to synthetic progesterone receptor (PR) agonists, so-called progestins, and transiently increases breast cancer risk. However, how contraceptive progestins affect the human breast epithelium is poorly understood, partially because of the lack of adequate preclinical models. We hypothesized that progestins are not all equal with regards to their effects on the human breast epithelium. To test this hypothesis, we employed reduction mammoplasty specimens derived from 40 women to establish in vivo preclinical models and show that different progestins have distinct biological activities in the breast epithelium depending on their androgenic properties. Androgen receptor inhibition interfered cell proliferation driven by the androgenic levonorgestrel, suggesting that androgenic progestins rely on AR to drive cell growth. Hence, we aimed to characterize the role that AR signaling pathway plays in the human breast epithelium, and we hypothesized that AR activation is sufficient for HBECs proliferation. We show that DHT treatments promote the proliferation of human cells dependently on its plasma concentrations, while having opposite effects in the murine mammary epithelium. Image analysis suggests that DHT-driven proliferation occurs in a paracrine fashion. Global gene expression analyses of hormone-treated PDXs revealed that AR signaling activation strongly perturbs the transcriptional profile of HBECs and identified mTORc1 signaling as a targetable mediator of AR-driven proliferation. Interestingly, transcriptional profiling of progestin-treated PDXs detected mTORc1 signaling to be specifically enriched upon androgenic progestin treatments in HBECs, suggesting the AR-mTORc1 axis as a hitherto uncharacterized growth-promoting mechanism in HBECs. We conclude that AR signaling has a hitherto uncharacterized proliferative role in the breast epithelium which warrants caution when prescribing androgenic treatments, with important implications for breast cancer prevention.

EPFL2022

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

A high resolution LC-MS targeted method for the concomitant analysis of 11 contraceptive progestins and 4 steroids

Alexandre Béguin, Cathrin Brisken, Fabio De Martino, Csaba Ferenc László, Marc Moniatte, Jonathan Paz Montoya, Marie Shamseddin

In the context of hormonal contraception and hormone replacement therapy (HRT), many women are exposed to exogenous hormones. Current use of hormonal contraception with combined ethinyl estradiol and different progestins bestows a breast cancer relative risk (RR) of 1.2-while combined HRT has a RR of 2. Although these exposures present an important public health issue, little is known about the effects of individual progestins on the breast and other tissues. Increasing availability of large scale biobanks, high throughput analyses and data management tools enable ever expanding, sophisticated population studies. In order to address the impact of distinct progestins on various health indicators, it is desirable to accurately quantify progestins in clinical samples. Here we have developed and validated a high resolution liquid chromatography mass spectrometry (LC-MS) targeted method for the simultaneous quantification of 11 synthetic progestins widely used in oral contraceptives, gestodene, levonorgestrel, etonogestrel, chlormadinone acetate, cyproterone acetate, drospirenone, desacetyl norgestimate, medroxyprogesterone acetate, norethindrone, dienogest, nomegestrol acetate, and 4 endogenous steroid hormones, progesterone, testosterone, androstenedione, and cortisol in blood samples. This highly specific quantitative analysis with high resolution Orbitrap technology detects and quantifies 15 compounds using their internal standard counterparts in a single 12 min LC-MS run. Sensitivity is attained by the use of the instrument in targeted selected ion monitoring mode. Lower limit of quantitation ranges from 2.4 pg/ml for drospirenone to 78.1 pg/ml for chlormadinone acetate. The method provides comprehensive progestin panel measurements with as little as 50 pi of murine or human plasma. (C) 2019 The Authors. Published by Elsevier B.V.

2019

Role of the androgen receptor in the human breast epithelium

Fabio De Martino

EPFL2022

A high resolution LC-MS targeted method for the concomitant analysis of 11 contraceptive progestins and 4 steroids

Alexandre Béguin, Cathrin Brisken, Fabio De Martino, Csaba Ferenc László, Marc Moniatte, Jonathan Paz Montoya, Marie Shamseddin

2019