The glycocalyx is a cell surface sugar layer of most cell types that greatly influences
the interaction of cells with their environment. Its components are glycolipids, glycoproteins,
and oligosaccharides. Interestingly, cancer cells have a thicker glycocalyx layer
compared to healthy cells, but to date, there has been no con- sensus in the literature
on the exact role of cell surface polysaccharides and their derivatives in cellular
adhesion and signaling. In our previous work we discovered that specific glycocalyx
components of cancer cells regulate the kinetics and strength of adhesion on RGD (arginine-glycine-aspartic
acid) peptide- coated surfaces [1]. Depending on the employed enzyme concentration
digesting specific components both adhesion strengthening and weakening could be observed
by monitoring the averaged behavior of thousands of cells. The enzyme chondroitinase
ABC (ChrABC) was used to digest the chondroitin-4-sulfate, chondroitin-6-sulfate,
and dermatan sulfate components in the glycocalyx of cancer cells. In the present
work, a high spatial resolution label-free optical biosensor was employed to monitor
the adhesivity of cancer cells both at the single-cell and population level. Population-level
distributions of single-cell adhesivity were first recorded and analyzed when ChrABC
was added to the adhering cells. At relatively low and high ChrABC concentrations
subpopulations with remarkably large and weak adhesivity were identified. The changes
in the adhesivity distribution due to the enzyme treatment were analyzed and the subpopulations
most affected by the enzyme treatment were highlighted. The presented results open
up new directions in glycocalyx related cell adhesion research and in the development
of more meaningful targeted cancer treatments affecting adhesion.