Three-dimensional microtissues essentially contribute to preclinical validations of therapeutic targets in breast cancer.

Natalie Falkenberg,Sabine Richter,Kenji Schorpp,Michaela Aubele,Kamyar Hadian,Michael J Atkinson,Michael Rosemann,Justine Szumielewski,Ines Höfig,Nataša Anastasov

doi:10.1002/cam4.630

Abstract

A 3D microtissues using T47D and JIMT‐1 cells were generated to analyze tissue‐like response of breast cancer cells after combined human epidermal growth factor receptor 2 (HER2)‐targeted treatment and radiation. Following lentiviral knockdown of HER2, we compared growth rate alterations using 2D monolayers, 3D microtissues, and mouse xenografts. Additionally, to model combined therapeutic strategies, we treated HER2‐depleted T47D cells and 3D microtissues using trastuzumab (anti‐HER2 antibody) in combination with irradiation. Comparison of HER2 knockdown with corresponding controls revealed growth impairment due to HER2 knockdown in T47D 2D monolayers, 3D microtissues, and xenografts (after 2, 12, and ≥40 days, respectively). In contrast, HER2 knockdown was less effective in inhibiting growth of trastuzumab‐resistant JIMT‐1 cells in vitro and in vivo. Combined administration of trastuzumab and radiation treatment was also analyzed using T47D 3D microtissues. Administration of both, radiation (5 Gy) and trastuzumab, significantly enhanced the growth inhibiting effect in 3D microtissues. To improve the predictive power of potential drugs—as single agents or in combination—here, we show that regarding tumor growth analyses, 3D microtissues are highly comparable to outcomes derived from xenografts. Considering increased limitations for animal experiments on the one hand and strong need of novel drugs on the other hand, it is indispensable to include highly reproducible 3D microtissue platform in preclinical analyses to validate more accurately the capacity of future drug‐combined radiotherapy.

Highlights

Proliferation assays of two-dimensional (2D) monolayer cancer cells are too artificial for anti-cancer drug screening and fail to model three-dimensional (3D) solid tumor [1, 2]
To improve the predictive power of potential drugs - as single agents or in combination – here, we show that regarding tumor growth analyses, 3D microtissues are highly comparable to outcomes derived from xenografts
Growth analysis of tumor cells cultivated as 3D microtissues is more comparable to in vivo xenografts than to outcomes of 2D monolayers To compare short- with long-term analysis of growth rates, T47D and JIMT-1 cells were cultured in 2D, 3D or as xenografts (Figure 1 and Supplementary Fig. S1A and S1C)

Summary

Introduction

Proliferation assays of two-dimensional (2D) monolayer cancer cells are too artificial for anti-cancer drug screening and fail to model three-dimensional (3D) solid tumor [1, 2]. Multicellular 3D spheroid models have been proven to be more physiologically relevant to in vivo tumors. Sutherland and colleagues pioneered in 3D cell culture model generating Chinese hamster lung spheroids in rotary flasks 4. 3D models can help investigating the interplay between different physiological conditions (oxygen or nutrient deprivation), irradiation or other physical and chemical stimuli [9, 10]. They allow for long-term studies of several weeks [9, 11, 12]. In 1998, the antibody-based targeted therapy for HER2-positive tumors using trastuzumab has shown a survival benefit 16. To improve HER2-targeted therapy, we treated T47D microtissues with trastuzumab combined with radiation in 2D and 3D

Methods

Results

Conclusion