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

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.

Targeting Cancer Cell Tight Junctions Enhances PLGA-Based Photothermal Sensitizers’ Performance In Vitro and In Vivo

“…Since the efficacy of both low molecular weight compounds and supramolecular structures differs significantly within in vitro and in vivo models, 3D spheroids are often used as an intermediate step as a more relevant tool for studying drug efficacy [21][22][23][24][25]. In particular, in spheroids, cells form tight intercellular contacts, which are often the main reason for the poor penetration of therapeutic substances into the tumor.…”

Three-Dimensional in Vitro Models: A Promising Tool To Scale-Up Breast Cancer Research

“…They reported that each spheroid’s tumor microenvironment properties were different and found that the antitumor potency toward TNBC spheroids was higher than that toward HER2 + cells. Spheroids were generally more resistant to the tested peptides than monolayers …”

“…This demonstrates that the combination of PET tracers with spheroids and SASDM are good models for monitoring of breast cancer treatment with anticancer drugs. 35 In another study, Cavaco et al 36 developed and characterized spheroids from the most aggressive breast cancer subtypes (human-epidermal growth factor receptor-2 positive (HER2 + ) and TNBC cell lines) and also compared the efficacy of a model anticancer peptide (ACP) in both 2D (monolayer) and 3D (spheroid) cell culture models. They reported that each spheroid's tumor microenvironment properties were different and found that the antitumor potency toward TNBC spheroids was higher than that toward HER2 + cells.…”

“…Spheroids were generally more resistant to the tested peptides than monolayers. 36 Drug testing can also be performed on patient-derived spheroids. For example, Halfter et al 37 used patient-derived spheroids to develop a predictive test for identifying the best treatment for HER2-negative breast cancer patients in all stages.…”

Gradient Retention Factor Concept Applied to Method Development for Peptide Analysis by Means of RP-HPLC

“…Peptides have great advantages as drugs because they have unique therapeutic properties, are usually harmless, and act on specific targets of physiological processes . Peptides that fulfill functions of regulation, modulation, and/or activation of the immune system, transport, biomarkers, and antimicrobial and anticancer activities, among others, have been described. , Recent advances in peptide therapeutics include progress from synthetic methods and in the use of naturally occurring peptides, which have intrinsic weaknesses, to a sophisticated system of drug development based on drug discovery and design, peptide synthesis, and structural modification for activity evaluation. − …”