Fig. 1

a Nicotine and E-cigarette extracts promote the self-renewal of stem-like SP cells from A549 cells; similar results were obtained on H1650 cells (b). SP represents side population and MP represents main population cells. Depletion of Sox2 using a siRNA abrogates the self-renewal of SP cells from A549 cells (c) or H1650 cells (d). Nicotine and E-cigarette extracts induce EMT-like changes in A549 cells. Immunofluorescence experiments using an antibody to ZO1 shows that nicotine and E-cigarette extracts reduce the tight junctions effectively (red fluorescence); CRM1 and DAPI are used to visualize the cells (e). Similar results were observed with E-cadherin (f). g A RT-PCR experiment shows the induction of mesenchymal markers vimentin and fibronectin as well as ZEB1 and ZEB2. The data presented here is with ± standard deviation (SD) values derived from three independent experiments. The statistical comparisons between the groups were carried out by unpaired two tailed Student’s t-test. h-i Nicotine and E-cigarette extracts promote the migration of A549 cells on plastic, as seen by a wound-healing assay (h) and the healing of the wound was represented graphically as % wound area over time (i). The statistical comparison between the groups was carried out by unpaired two tailed Student’s t-test