RA treatment reduces SK-N-SK neuroblastoma cell motility. (A) Representative PC images of untreated (Control) or 6 days RA treated cells which motility has been analyzed by scratch test. Images show the starting (0 hr after scratch) and the end (24 hr after scratch) point of the analysis. In control the distance between the borderlines becomes significantly shorter 24 hr after wounding, while it is still elevated in RA treated samples. (B) IF DCX analysis performed both in control and in RA treated cells 24 hr after wounding. In control samples the majority of invading cells are DCX+ (red). Even if the migration rate of the treated cells is reduced, few of them move in and invade the scratched area; all the cells still migrating after 6 days RA treatment are DCX+ (inset 1 and 2 of panel B are magnified in panel C). Nuclei are counterstained with DAPI (blue).