Microfluidic cytometric analysis of cancer cell transportability and invasiveness.

Zongbin Liu,Xin Han,Ying Li,Ledu Zhou,Yeonju Lee,Kenji Yokoi,Mauro Ferrari,Lidong Qin,Joon Hee Jang

doi:10.1038/srep14272

Abstract

The extensive phenotypic and functional heterogeneity of cancer cells plays an important role in tumor progression and therapeutic resistance. Characterizing this heterogeneity and identifying invasive phenotype may provide possibility to improve chemotherapy treatment. By mimicking cancer cell perfusion through circulatory system in metastasis, we develop a unique microfluidic cytometry (MC) platform to separate cancer cells at high throughput, and further derive a physical parameter ‘transportability’ to characterize the ability to pass through micro-constrictions. The transportability is determined by cell stiffness and cell-surface frictional property, and can be used to probe tumor heterogeneity, discriminate more invasive phenotypes and correlate with biomarker expressions in breast cancer cells. Decreased cell stiffness and cell-surface frictional force leads to an increase in transportability and may be a feature of invasive cancer cells by promoting cell perfusion through narrow spaces in circulatory system. The MC-Chip provides a promising microfluidic platform for studying cell mechanics and transportability could be used as a novel marker for probing tumor heterogeneity and determining invasive phenotypes.

Highlights

IntroductionOur MC platform possesses two key features: (1) deterministic lateral displacement (DLD), a microfluidic size-based particle-sorting technique that employs tilted rows of microposts, to separate cancer cells by size and (2) a rectangular microarray of trapping barriers with gaps decreasing in width from 15 μ m to 4 μ m that is comparable to blood capillary diameter ranging from 6 μ m to 9 μ m, to trap the cells (Fig. 1a)
Young’s modulus and μ is friction coefficient. (b) The overview shows the cell and buffer inlets on the microfluidic device, scale bar = 1 cm. (c) deterministic lateral displacement (DLD) structure design is shown
Cells are separated by size using the DLD structure (Supplementary Movie S1) consisting of rows of triangular microposts arranged with a tilted angle that increases from 2.9° to 14.7° between the inlet and outlet side of the device (Fig. 1c)

Summary

Introduction

Our MC platform possesses two key features: (1) deterministic lateral displacement (DLD), a microfluidic size-based particle-sorting technique that employs tilted rows of microposts, to separate cancer cells by size and (2) a rectangular microarray of trapping barriers with gaps decreasing in width from 15 μ m to 4 μ m that is comparable to blood capillary diameter ranging from 6 μ m to 9 μ m, to trap the cells (Fig. 1a) These features separate cells into a unique two-dimensional distribution; cells of increasing diameter are distributed across the width of the device and transportability increases in the flow direction. The MC-Chip was used to study the heterogeneity of cells from a mouse tumor xenograft by comparing the transportability of cells dissociated from the center and the periphery of a tumor

Methods

Results

Conclusion