3D Cell Culture for the Study of Microenvironment-Mediated Mechanostimuli to the Cell Nucleus: An Important Step for Cancer Research.

Apekshya Chhetri,Sophie A Lelièvre,Joseph V Rispoli

doi:10.3389/fmolb.2021.628386

Apekshya Chhetri, Sophie A Lelièvre + Show 1 more

Open Access

https://doi.org/10.3389/fmolb.2021.628386

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Abstract

The discovery that the stiffness of the tumor microenvironment (TME) changes during cancer progression motivated the development of cell culture involving extracellular mechanostimuli, with the intent of identifying mechanotransduction mechanisms that influence cell phenotypes. Collagen I is a main extracellular matrix (ECM) component used to study mechanotransduction in three-dimensional (3D) cell culture. There are also models with interstitial fluid stress that have been mostly focusing on the migration of invasive cells. We argue that a major step for the culture of tumors is to integrate increased ECM stiffness and fluid movement characteristic of the TME. Mechanotransduction is based on the principles of tensegrity and dynamic reciprocity, which requires measuring not only biochemical changes, but also physical changes in cytoplasmic and nuclear compartments. Most techniques available for cellular rheology were developed for a 2D, flat cell culture world, hence hampering studies requiring proper cellular architecture that, itself, depends on 3D tissue organization. New and adapted measuring techniques for 3D cell culture will be worthwhile to study the apparent increase in physical plasticity of cancer cells with disease progression. Finally, evidence of the physical heterogeneity of the TME, in terms of ECM composition and stiffness and of fluid flow, calls for the investigation of its impact on the cellular heterogeneity proposed to control tumor phenotypes. Reproducing, measuring and controlling TME heterogeneity should stimulate collaborative efforts between biologists and engineers. Studying cancers in well-tuned 3D cell culture platforms is paramount to bring mechanomedicine into the realm of oncology.

Highlights

Force variations at the cellular level are a source of biological modifications that influence organ development and homeostasis (Eckes and Krieg, 2004; Mammoto and Ingber, 2010; Humphrey et al, 2014; Schroer and Merryman, 2015; Barnes et al, 2017)
The importance of 3D cell culture to study the nucleus was initially demonstrated via the dynamic distribution of the nuclear structural protein NuMA that responds to extracellular matrix (ECM) signaling (Lelièvre, et al, 1998; Vidi et al, 2012), and itself controls phenotypically normal differentiation via an action on the epigenome (Abad et al, 2007)
A fundamental question to address with 3D cell culture is whether increased tumor microenvironment (TME) stiffness during cancer progression modifies the intratumor phenotypic heterogeneity that defines aggressiveness; we measured potential selective pressure in light of a higher apoptotic rate in breast tumors cultured in 3300 Pa compared to 2000 Pa (Figure 2C), confirming observations made previously of a link between high mechanical stress, measured in an agarose matrix with fluorescent microbeads, and apoptosis (Cheng et al, 2009)

Summary

Introduction

Force variations at the cellular level are a source of biological modifications that influence organ development and homeostasis (Eckes and Krieg, 2004; Mammoto and Ingber, 2010; Humphrey et al, 2014; Schroer and Merryman, 2015; Barnes et al, 2017). Cell culture models that integrate ECM and microfluidics to study cancer progression via an influence on the phenotypic heterogeneity of cancers are discussed to highlight how they might feed information necessary for the development of mechanomedicine.

Results

Conclusion