Use of OCT to study tumour cell growth in 3D membranes

Mesothelioma is a tumour, usually fatal, which arises from and invades the pleural membrane. Investigation of the tumour cell-membrane interaction will greatly increase our understanding of the invasion mechanisms, which have the potential to improve the management of the disease. In this study, a new imaging technique, optical coherence tomography (OCT), was used to monitor tumour cell invasion in artificial membranes composed of either collagen type I or Matrigel. In parallel, standard histological section analysis was performed to validate the accuracy of the monitoring by OCT. Cross-sectional images from OCT revealed that lung tumour cells invaded only when low cell seeding density (5 x 105) and low collagen concentration (1.5 mg/ml) were combined. The cells could be easily differentiated from the artificial membranes and appeared as either a brighter layer on the top of the membrane or brighter spots embedded within the darker membrane. These cell-membrane morphologies matched remarkably to the standard histological section images. Our results suggest that OCT has a great potential to become a useful tool for fast and robust assessment of cell invasion.