Assembly of Epithelial Monolayers and Transmigration of Cancer Cells Captured with Phase Holographic Imaging

Cellular monolayers have a fundamental role in the development of embryos, vascularization, organ formation, attachment to artificial implants, and metastasis of cancerous cells. Phase holographic imaging was used to monitor the time-dependent behavior of cancerous HeLa cells. After monitoring the assembly of epithelial Vero monolayer on a gelatin-coated surface, HeLa cells were seeded on top of the monolayer, and their transmigration was observed. This method is label-free and non-toxic to cells and enables the visualization of living cells in real-time and analyze their parameters such as motility and morphology. HeLa cells seeded on the tight Vero monolayer (100 % confluency) were observed for 24 hours, and a 60 minute time period has been selected for further analysis that showed the difference in cellular parameters between non-invasive and invasive HeLa cells in the observed time frame. Our investigations revealed that invasive HeLa cells have reduced area and optical volume compared to noninvasive HeLa cells, corresponding to the phase shift detected in transmigration events.