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Published on: April 26, 2024
Spheroids of HER2-Positive Breast Adenocarcinoma for Studying Anticancer Immunotoxins In Vitro
I V Balalaeva1,2, E A Sokolova1,2, A D Puzhikhina1
1Lobachevsky State University of Nizhny Novgorod, Gagarin Ave., 23, Nizhny Novgorod, 603950, Russia.
Abstract:
Tumor response to therapeutic treatment is largely determined by its heterogeneity and the presence of intercellular junctions, hindering the penetration of large molecules deep into the three-dimensional structure of the tumor. In that context, 3D in vitro tumor models such as cancer cell spheroids are becoming increasingly popular. We obtained spheroids of human breast adenocarcinoma SKBR-3 overexpressing the HER2 cancer marker. The toxicity of HER2-targeted immunotoxin 4D5scFv-PE40 against spheroids was shown to be several orders of magnitude lower compared to a monolayer cell culture. The significant difference in the severity of the immunotoxin effect can be explained by the fact that it ineffectively penetrates the spheroid and predominantly influences the cells of the outer layers. The resulting tumor spheroid model can be used in development of drugs for targeted therapy as well as to study ways to improve the efficiency of anticancer agents by targeting cell-cell contacts.
Insights
Three-dimensional (3D) tumor spheroids, unlike 2D cultures, show reduced sensitivity to targeted immunotoxins due to poor drug penetration. This highlights the importance of 3D models for cancer drug development.
Area of Science:
- Oncology
- Biotechnology
- Pharmacology
Background:
- Tumor heterogeneity and intercellular junctions impede drug delivery in 3D tumor structures.
- Three-dimensional (3D) in vitro tumor models, such as cancer cell spheroids, are gaining traction for studying drug efficacy.
- SKBR-3 human breast adenocarcinoma cells overexpressing the HER2 marker were utilized.
Purpose of the Study:
- To evaluate the efficacy of a HER2-targeted immunotoxin (4D5scFv-PE40) in a 3D tumor spheroid model.
- To compare the drug's effect on spheroids versus traditional monolayer cell cultures.
- To explore the utility of 3D tumor models in drug development and optimizing anticancer agent delivery.
Main Methods:
- Generation of 3D tumor spheroids from HER2-positive SKBR-3 breast adenocarcinoma cells.
- Treatment of spheroids and monolayer cultures with the HER2-targeted immunotoxin 4D5scFv-PE40.
- Comparative analysis of immunotoxin toxicity and penetration in both model systems.
Main Results:
- The HER2-targeted immunotoxin exhibited significantly lower toxicity against 3D tumor spheroids compared to monolayer cultures.
- Ineffective penetration of the immunotoxin into the spheroid core was observed, with effects primarily on outer layers.
- The study demonstrated a substantial difference in drug efficacy between 2D and 3D tumor models.
Conclusions:
- 3D tumor spheroids provide a more realistic model for assessing drug penetration and efficacy, especially for large molecules.
- The reduced efficacy of 4D5scFv-PE40 in spheroids underscores the challenge of targeting deep tumor tissues.
- This 3D model is valuable for developing targeted therapies and investigating strategies to overcome drug delivery barriers, such as targeting cell-cell contacts.
