DOI: 10.5061/dryad.h44j0zpf4
title: Data from: Collective forces of tumor spheroids in three-dimensional biopolymer networks

description: We describe a method for quantifying the contractile forces that tumor
 spheroids collectively exert on highly nonlinear three-dimensional
 collagen networks. While three-dimensional traction force microscopy for
 single cells in a nonlinear matrix is computationally complex due to the
 variable cell shape, here we exploit the spherical symmetry of tumor
 spheroids to derive a scale-invariant relationship between spheroid
 contractility and the surrounding matrix deformations. This relationship
 allows us to directly translate the magnitude of matrix deformations to
 the total contractility of arbitrarily sized spheroids. We show that our
 method is accurate up to strains of 50% and remains valid even for
 irregularly shaped tissue samples when considering only the deformations
 in the far field. Finally, we demonstrate that collective forces of tumor
 spheroids reflect the contractility of individual cells for up to 1h after
 seeding, while collective forces on longer timescales are guided by
 mechanical feedback from the extracellular matrix.
description: LuB25-spheroid.zip This zip-file contains a
 series of brightfield images through the equatorial plane of a spheroid
 created from 4,000 primary mesenchymal Luminal-B breast cancer cells. The
 spheroid is embedded in a three-dimensional 1.2mg/ml collagen gel,
 together with micron-sized fiducial markers. Images were taken at an
 interval of 10min, spanning a period of 24h in total. The pixel-size of
 the image series is 1.02µm.
 Triduc1-spheroid.zip This zip-file contains
 a series of brightfield images through the equatorial plane of a spheroid
 created from 4,000 primary mesenchymal triple-negative breast cancer
 cells. The spheroid is embedded in a three-dimensional 1.2mg/ml collagen
 gel, together with micron-sized fiducial markers. Images were taken at an
 interval of 10min, spanning a period of 24h in total. The pixel-size of
 the image series is 1.02µm.
 LuB25-tumoroids.zip Each subfolder within
 this zip-file contains a series of brightfield images through the
 equatorial plane of a Luminal-B breast cancer tumoroid (tumor tissue
 sample). The tumoroids are embedded in a three-dimensional 1.2mg/ml
 collagen gel, together with micron-sized fiducial markers. Images were
 taken at an interval of 10min, spanning a period of 24h in total. The
 pixel-size of the image series is 1.02µm.
 A172-15000-spheroids.zip This zip-file
 contains three subfolders, each of which represents an independent
 experiment (biological replication). Each subfolder contains series of
 brightfield images through the equatorial plane of multiple spheroids
 (technical replication) created from 15,000 A172 glioblastoma cancer
 cells. The spheroids are embedded in a three-dimensional 1.2mg/ml collagen
 gel, together with micron-sized fiducial markers. Images were taken at an
 interval of 5min, spanning a period of 12h in total. The pixel-size of the
 image series is 1.29µm.
 U87-15000-spheroids.zip This zip-file
 contains three subfolders, each of which represents an independent
 experiment (biological replication). Each subfolder contains series of
 brightfield images through the equatorial plane of multiple spheroids
 (technical replication) created from 15,000 U87 (full name: U-87 MG)
 glioblastoma cancer cells. The spheroids are embedded in a
 three-dimensional 1.2mg/ml collagen gel, together with micron-sized
 fiducial markers. Images were taken at an interval of 5min, spanning a
 period of 12h in total. The pixel-size of the image series is
 1.29µm. U87-7500-spheroids.zip
 This zip-file contains three subfolders, each of which represents
 an independent experiment (biological replication). Each subfolder
 contains series of brightfield images through the equatorial plane of
 multiple spheroids (technical replication) created from 15,000 U87 (full
 name: U-87 MG) glioblastoma cancer cells. The spheroids are embedded in a
 three-dimensional 1.2mg/ml collagen gel, together with micron-sized
 fiducial markers. Images were taken at an interval of 5min, spanning a
 period of 12h in total. The pixel-size of the image series is
 1.29µm.