Abstract 178: Quantification of matrix remodeling during H1299 lung cancer cell migration in microfluidic devices
Authors: Anguiano Maria , Morales Xabier , Ariz Mikel , Villar Martín Martínez , Ortiz-de-Solorzano Carlos 
Published: August 2018

Abstract
Introduction
Metastasis is a hallmark of cancer and represents a major clinical challenge. Since cell migration is a key process for metastasis, it is of great importance to understand the mechanisms of cancer cell migration. In the last decade, novel microfluidic devices, containing extracellular matrix (ECM) biomimetic hydrogels, have become attractive tools to recapitulate the tumor microenvironment, thus permitting the study of cancer cell migration in a more physiological 3D environment.
Previously, we have used microfluidic platforms, filled with hydrogels of mixed collagen-Matrigel composition, to investigate the effect of the microenvironment on H1299 NSCLC migration, and demonstrated how the biomechanical properties of the hydrogels determined the phenotype and migration speed of the cells. We concluded that a balanced composition of collagen and Matrigel favors cell migration, due to an increased matrix stiffness and pore size of the hydrogels.
Objectives
To further examine the impact of the ECM on cell migration, we now quantify matrix remodeling due to metalloproteinase (MMP) activity during H1299 migration, in mixed collagen-Matrigel hydrogels. Our second goal is to study the relationship between H1299 cancer cell migration and H1299 integrin expression levels in the same hydrogels, to understand how integrin profile is modulated by hydrogel composition.
Methods
We used three different hydrogels with the same collagen concentration of 2 mg/ml and 0 (C), 2 (CM) and 4 (CM+) mg/ml of Matrigel respectively. Proteolytic degradation of hydrogel caused during H1299 cell migration was quantified as the volume of a dye-quenched protein substrate (DQ collagen I) at 25 µg/ml, imaged by confocal microscopy (40X) and measured using in-house developed image analysis tools.
β1 and β3 integrin expression at cell surface was quantified by flow cytometry after stimulating cell migration inside the hydrogels for 24 h.
Results
The DQ volume per cell ratio revealed the proteolytic degradation was ~5 times higher in Matrigel-containing hydrogels CM and CM+ than in collagen-only hydrogel C. Cytometry assays showed β1 integrin is expressed by H1299 cells significantly more than β3 integrin in all three hydrogels. Moreover, we found β1 integrin expression at cell surface was higher in CM and CM+ hydrogels than in C hydrogels.
Conclusions
Hydrogel composition modifies H1299 integrin profile at cell surface. Accordingly, β1 integrin expression is higher than β3 integrin expression in all hydrogels studied as a result of collagen type I being the main binding ligand to β1 integrin.
Matrigel, at an intermediate, balanced concentration, enhances cell migration by stimulating both integrin expression at cell surface and matrix degradation due to MMP activity, thus compensating the higher degree of cell confinement compared to collagen-only hydrogels.
Citation Format: Maria Anguiano, Xabier Morales, Mikel Ariz, Martín Martínez Villar, Carlos Ortiz-de-Solorzano. Quantification of matrix remodeling during H1299 lung cancer cell migration in microfluidic devices [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 178.