Diffusion-induced anisotropic cancer invasion: a novel experimental method based on tumour spheroids

TL;DR

This paper introduces a new experimental method using live imaging of tumour spheroids in 3D collagen gel to quantitatively study chemotaxis and invasion behavior under controlled nutrient gradients.

Contribution

It presents a novel in vitro assay combining live imaging and transport phenomena analysis to investigate tumor cell invasion in response to chemotactic stimuli.

Findings

Tumour spheroids respond differently to nutrient gradients based on cell type.

Tumor cells show stronger invasion responses compared to non-tumoral cells.

The method allows detailed observation and quantification of invasion phenomena.

Abstract

Tumour invasion is strongly influenced by microenvironment and, among other parameters, chemical stimuli play an important role. An innovative methodology for the quantitative investigation of chemotaxis in vitro by live imaging of morphology of cell spheroids, in 3D collagen gel, is presented here. The assay was performed by using a chemotactic chamber to impose a controlled gradients of nutrients (glucose) on spheroids, mimicking the chemotactic stimuli naturally occurring in the proximity of blood vessels. Different tumoral cell lines (PANC-1 and HT-1080) are compared to non-tumoral ones (NIH/3T3). Morphology response is observed by means a Time-lapse workstation equipped with an incubating system and quantified by image analysis techniques. Description of invasion phenomena was based on an engineering approach, based on transport phenomena concepts. As expected, NIH/3T3 spheroids are characterized by a limited tendency of cells to invade the surrounding tissue, unlike PANC-1 and HT-1080 that show relatively stronger response to gradients.