Figure 2.

Penetration kinetics of parental control cells (UKF-NB-2, UKF-NB-4) versus vincristine (UKF-NB-2^VCR, UKF-NB-4^VCR) or doxorubicin resistant subpopulations (UKF-NB-2^DOX, UKF-NB-4^DOX). To identify transmigrated NB from the cells which had bound to HUVEC, a reflection interference contrast microscope with a Ploem apparatus was used (see materials and methods for details). X-axis indicates the period of co-culture. *indicates significant difference to the controls.