Development of Breast Cancer Spheroids to Evaluate Cytotoxic Response to an Anticancer Peptide.

Marco Cavaco,David Andreu,Patrícia Fraga,Vera Neves,Javier Valle,Miguel A R B Castanho

doi:10.3390/pharmaceutics13111863

Marco Cavaco, David Andreu + Show 4 more

Open Access

https://doi.org/10.3390/pharmaceutics13111863

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Abstract

Breast cancer (BC) is the most commonly diagnosed cancer in women and one of the most common causes of cancer-related deaths. Despite intense research efforts, BC treatment still remains challenging. Improved drug development strategies are needed for impactful benefit to patients. Current preclinical studies rely mostly on cell-based screenings, using two-dimensional (2D) cell monolayers that do not mimic in vivo tumors properly. Herein, we explored the development and characterization of three-dimensional (3D) models, named spheroids, of the most aggressive BC subtypes (triple-negative breast cancer-TNBC; and human-epidermal growth receptor-2-HER2+), using the liquid overlay technique with several selected cell lines. In these cell line-derived spheroids, we studied cell density, proliferation, ultrastructure, apoptosis, reactive oxygen species (ROS) production, and cell permeabilization (live/dead). The results showed a formation of compact and homogeneous spheroids on day 7 after seeding 2000 cells/well for MDA-MB-231 and 5000 cells/well for BT-20 and BT-474. Next, we compared the efficacy of a model anticancer peptide (ACP) in cell monolayers and spheroids. Overall, the results demonstrated spheroids to be less sensitive to treatment than cell monolayers, revealing the need for more robust models in drug development.

Highlights

Over the last decade, breast cancer (BC) diagnosis and treatment have significantly improved, resulting in better disease management
The optimization of MDA-MB-231, BT-20, and BT-474 spheroids was carried out using an initial cell density of 50 to 10,000 cells/well in the presence of 2% (v/v) GelTrex® over
Our results showed that spheroids produced with either 2000 cells/well (MDA-MB-231) or 5000 cells/well (BT-20 and BT-474) reached a stable diameter and higher metabolic activity at 7 days (Figure 1)

Summary

Introduction

Breast cancer (BC) diagnosis and treatment have significantly improved, resulting in better disease management. BC is still one of the leading causes of cancer-related deaths among women worldwide [1]. The classification of BCs into different subtypes is important to select adequate therapeutic options and evaluate prognosis, with the histological profile as one of the most important criteria. Erα is expressed in 75% of invasive BCs, and it is closely related to the expression of the progesteronereceptor (PR) [5,6]. HER2 is amplified or overexpressed in 15–20% of BCs [7,8]. Triple-negative breast cancer (TNBC), which corresponds to approximately 10–15% of BCs, is characterized by the lack of ER/PR and HER2 expression [9,10]

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