Generation and functional characterization of murine mammary organoids

Methods for Imaging Intracellular Calcium Signals in the Mouse Mammary Epithelium in Two and Three Dimensions

The mammary gland has a central role in optimal mammalian development and survival. Contractions of smooth muscle-like basal (or myoepithelial) cells in the functionally mature mammary gland in response to oxytocin are essential for milk ejection and are tightly regulated by intracellular calcium (Ca2+). Using mice expressing a genetically encoded Ca2+ indicator (GCaMP6f), we present in this chapter a method to visualize at high spatiotemporal resolution changes in intracellular Ca2+ in mammary epithelial cells, both in vitro (2D) and ex vivo (3D). The procedure to optimally prepare mammary tissue and primary cells is presented in detail.

Oncogenic Pathways and Targeted Therapies in Ovarian Cancer

Epithelial ovarian cancer (EOC) is one of the most aggressive forms of gynaecological malignancies. Survival rates for women diagnosed with OC remain poor as most patients are diagnosed with advanced disease. Debulking surgery and platinum-based therapies are the current mainstay for OC treatment. However, and despite achieving initial remission, a significant portion of patients will relapse because of innate and acquired resistance, at which point the disease is considered incurable. In view of this, novel detection strategies and therapeutic approaches are needed to improve outcomes and survival of OC patients. In this review, we summarize our current knowledge of the genetic landscape and molecular pathways underpinning OC and its many subtypes. By examining therapeutic strategies explored in preclinical and clinical settings, we highlight the importance of decoding how single and convergent genetic alterations co-exist and drive OC progression and resistance to current treatments. We also propose that core signalling pathways such as the PI3K and MAPK pathways play critical roles in the origin of diverse OC subtypes and can become new targets in combination with known DNA damage repair pathways for the development of tailored and more effective anti-cancer treatments.

Effects of 5-fluorouracil, thymoquinone, and mammary stem cells' exosomes on in vitro cultured breast cancer cells

Background

5-fluorouracil (5-FU) is an antimetabolic agent used for treating slowly growing solid tumors like breast and ovarian carcinoma. Thymoquinone (TQ) is the main biologically active constituent of Nigella sativa, it has been found to demonstrate anticancerous effects in several preclinical studies, and this is because TQ possesses multitarget nature. Stem cells-derived exosomes are in the spotlight of research and are promising tissue regenerative and anticancer cell-derived nanovesicles.

Aim

Herein, we studied the antineoplastic effects of Exosomes derived from mammary stem cells (MaSCs-Exo) on breast cancer cells, alone or combined with TQ when compared to a breast cancer chemotherapeutic agent; 5-FU.

Methods

Our approach included performing viability test and measuring the expression of pro-apoptotic gene (Bax), anti-apoptotic gene (BCL-2) and angiogenic gene (VEGF) on Human MCF-7 cells (breast adenocarcinoma cells), the MCF-7 cells were cultured and incubated with medium containing 5-FU (25 μg/ml), TQ (200 μg/ml), MaSCs-Exo (100 μg protein equivalent), a combination of TQ (200 μg/ml) and MaSCs-Exo (100 μg).

Results

Our obtained results show that TQ and MaSCs-Exo each can effectively inhibit breast cancer cell line (MCF-7) proliferation and growth. Also, the results show that the combination of TQ and MaSCs-Exo had higher cytotoxic effects on MCF-7 breast cancer cells than TQ or 5-FU, alone.

Conclusion

The present study shows a promising anticancer potential of exosomes isolated from mammary stem cells; this effect was potentiated by adding TQ with MaSCs-derived exosomes.

Exploring the interaction between extracellular matrix components in a 3D organoid disease model to replicate the pathophysiology of breast cancer

In vitro models are necessary to study the pathophysiology of the disease and the development of effective, tailored treatment methods owing to the complexity and heterogeneity of breast cancer and the large population affected by it. The cellular connections and tumor microenvironments observed in vivo are often not recapitulated in conventional two-dimensional (2D) cell cultures. Therefore, developing 3D in vitro models that mimic the complex architecture and physiological circumstances of breast tumors is crucial for advancing our understanding of the illness. A 3D scaffold-free in vitro disease model mimics breast cancer pathophysiology by allowing cells to self-assemble/pattern into 3D structures, in contrast with other 3D models that rely on artificial scaffolds. It is possible that this model, whether applied to breast tumors using patient-derived primary cells (fibroblasts, endothelial cells, and cancer cells), can accurately replicate the observed heterogeneity. The complicated interactions between different cell types are modelled by integrating critical components of the tumor microenvironment, such as the extracellular matrix, vascular endothelial cells, and tumor growth factors. Tissue interactions, immune cell infiltration, and the effects of the milieu on drug resistance can be studied using this scaffold-free 3D model. The scaffold-free 3D in vitro disease model for mimicking tumor pathophysiology in breast cancer is a useful tool for studying the molecular basis of the disease, identifying new therapeutic targets, and evaluating treatment modalities. It provides a more physiologically appropriate high-throughput platform for screening large compound library in a 96-384 well format. We critically discussed the rapid development of personalized treatment strategies and accelerated drug screening platforms to close the gap between traditional 2D cell culture and in vivo investigations.

Imagine beyond: recent breakthroughs and next challenges in mammary gland biology and breast cancer research

On 8 December 2022 the organizing committee of the European Network for Breast Development and Cancer labs (ENBDC) held its fifth annual Think Tank meeting in Amsterdam, the Netherlands. Here, we embraced the opportunity to look back to identify the most prominent breakthroughs of the past ten years and to reflect on the main challenges that lie ahead for our field in the years to come. The outcomes of these discussions are presented in this position paper, in the hope that it will serve as a summary of the current state of affairs in mammary gland biology and breast cancer research for early career researchers and other newcomers in the field, and as inspiration for scientists and clinicians to move the field forward.

In vitro breast cancer models for studying mechanisms of resistance to endocrine therapy

The development of endocrine resistance is a common reason for the failure of endocrine therapies in hormone receptor-positive breast cancer. This review provides an overview of the different types of in vitro models that have been developed as tools for studying endocrine resistance. In vitro models include cell lines that have been rendered endocrine-resistant by ex vivo treatment; cell lines with de novo resistance mechanisms, including genetic alterations; three-dimensional (3D) spheroid, co-culture, and mammosphere techniques; and patient-derived organoid models. In each case, the key discoveries, different analysis strategies that are suitable, and strengths and weaknesses are discussed. Certain recently developed methodologies that can be used to further characterize the biological changes involved in endocrine resistance are then emphasized, along with a commentary on the types of research outcomes that using these techniques can support. Finally, a discussion anticipates how these recent developments will shape future trends in the field. We hope this overview will serve as a useful resource for investigators that are interested in understanding and testing hypotheses related to mechanisms of endocrine therapy resistance.