Abstract 130P
Background
Lung cancer is known for its ability to spread readily in its early stages. After establishing a primary tumor site, lung cancer cells undergo vascular invasion. However, the exact mechanisms of the vascular invasion through lymphatic or blood vessels are not yet clearly understood. Current in vivo and in vitro models are incapable of answering mechanistic questions behind the dynamics of lung cancer metastasis. As an alternative approach, various engineered models have been emerged to mimic each step of the metastasis to examine different hypotheses by tuning features of the microenvironment. This study aims to investigate the extravasation dynamics of the two subpopulations of A549 adenocarcinoma cells in an isolated 3D microvasculature network in vitro.
Methods
A microfluidic platform was used to co-culture primary human endothelial cells and primary human fibroblasts in a hydrogel matrix. A perfusable 3D microvasculature network was formed within seven days. Two subpopulations of the A549 adenocarcinoma cells, holoclones, and paraclones were separately loaded in the microvasculature network in the chips. The microvasculatures incorporating the cancer cells were further incubated for 24 hours. The chips were stained for further immunohistochemistry analysis. The epithelial to mesenchymal transition (EMT) status of holoclones and paraclones was monitored by flow cytometry after being cultured for 24 hours in an endothelial growth medium.
Results
Our flow cytometry analysis showed that holoclones and paraclones both maintain a stable EMT phenotype after 24 hours of incubation in an endothelial growth medium. Holoclones and paraclones showed different extravasation capacities in vitro. Paraclones extravasate within 24 hours from the microvasculature network towards the surrounding tissue/hydrogel, whereby holoclones remain inside the microvasculature attached to the endothelial wall.
Conclusions
Our in vitro on-chip experiments showed that A549 holoclones and paraclones significantly differ in extravasation capacities. Our results showed the feasibility of the advanced in vitro microvasculatures to study the metastasis capacity of the cancer cells in vitro.
Legal entity responsible for the study
Organs-on-chip Technologies Laboratory, ARTORG Center, University of Bern.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.