A microfluidic chip for screening individual cancer cells via eavesdropping on autophagy-inducing crosstalk in the stroma niche

Hacer Ezgi Karakas,Yongjun Choi,Devrim Gozuacik,Yoon-Kyoung Cho,Juhee Park,Jung Min Oh,Junyoung Kim

doi:10.1038/s41598-017-02172-7

Abstract

Autophagy is a cellular homeostatic mechanism where proteins and organelles are digested and recycled to provide an alternative source of building blocks and energy to cells. The role of autophagy in cancer microenvironment is still poorly understood. Here, we present a microfluidic system allowing monitoring of the crosstalk between single cells. We used this system to study how tumor cells induced autophagy in the stromal niche. Firstly, we could confirm that transforming growth factor β1 (TGFβ1) secreted from breast tumor cells is a paracrine mediator of tumor-stroma interaction leading to the activation of autophagy in the stroma component fibroblasts. Through proof of concept experiments using TGFβ1 as a model factor, we could demonstrate real time monitoring of autophagy induction in fibroblasts by single tumor cells. Retrieval of individual tumor cells from the microfluidic system and their subsequent genomic analysis was possible, allowing us to determine the nature of the factor mediating tumor-stroma interactions. Therefore, our microfluidic platform might be used as a promising tool for quantitative investigation of tumor–stroma interactions, especially for and high-throughput screening of paracrine factors that are secreted from heterogeneous tumor cell populations.

Highlights

Interactions between cancer cells and the neighboring stroma play a critical role in tumorigenesis, and an in-depth understanding of intercellular communication is of great significance for the development of novel therapeutic strategies[1,2,3]
A single cell-based screening platform was developed, in which the degree of autophagy activation induced by the intercellular communication between tumor cells and fibroblasts was used as criteria
In these chips, trapping of single tumor cells in the membrane holes of the microfluidic chip followed by co-culture with adjacent fibroblasts was possible

Summary

Introduction

Interactions between cancer cells and the neighboring stroma play a critical role in tumorigenesis, and an in-depth understanding of intercellular communication is of great significance for the development of novel therapeutic strategies[1,2,3]. We designed a biochip system that allows the time-course measurement of cancer cell–stroma interactions at a single-cell level This was followed by molecular profiling of the retrieved individual cells, allowing the assessment of the correlation between phenotype distribution of intercellular interactions and their genetic bases. Recent studies indicate that autophagy in the stroma might play a key role in cancer–stroma interactions, helping to sustain tumor growth and metastasis[18,19,20]. In this context, it was proposed that non-protein mediators such as reactive oxygen species (ROS) and glutamine were responsible for the communication between tumor cells and stroma. The contribution of proteins and/or peptides during tumor-stroma interaction-mediated autophagy has not been studied in detail

Methods

Results

Conclusion