Fig. 1. Chronic exposure to cigarette smoke induces phenotypic changes in oral keratinocytes.

a Cellular morphology of OKF6/TERT1-Parental cells and OKF6/TERT1-Smoke cells (magnification 20X) (b) Growth curve depicting cellular proliferation rates of OKF6/TERT1-Parental and OKF6/TERT1-Smoke cells. c Transwell-based invasion assays were performed using Matrigel-coated chambers where number of cells that invade into the lower chamber were visualized (10× magnification) with methylene blue staining in OKF6/TERT1-Parental and OKF6/TERT1-Smoke cells. d Invaded cells were counted and relative changes in invasive ability of OKF6/TERT1-Parental and OKF6/TERT1-Smoke cells were calculated and represented graphically (***p < 0.0001). e Colony formation assay of smoke exposed and parental cells visualized (3× magnification) after staining with methylene blue. f Wound migration assays were carried out using OKF6/TERT1-Smoke and parental cells between 0 and 10 h. Cells were imaged at 10× magnification