Abstract
Ceramide is found to be involved in inhibition of cell division and induction of apoptosis in certain tumour cells. Ceranib-2 is an agent that increases ceramide levels by inhibiting ceramidase in cancer cells. Therefore, we aimed to investigate the effects of ceranib-2 on cell survival, apoptosis and interaction with carboplatin in human non-small cell lung cancer cells. The cytotoxic effect of ceranib-2 (1-100 µM) was determined by MTT assay in human lung adenocarcinoma (A549) and large cell lung carcinoma (H460) cells. Carboplatin (1-100 µM) and lung bronchial epithelial cells (BEAS-2B) were used as positive controls. Morphological and ultrastructural changes were analysed by light microscope and TEM. Apoptotic/necrotic cell death and acid ceramidase activity were analysed by ELISA. Combination effects of ceranib-2 and carboplatin were investigated by MTT. The expression levels of CASP3, CASP9, BAX and BCL-2 were examined by qRT-PCR. The IC50 of ceranib-2 was determined as 22 μM in A549 cells and 8 μM in H460 cells for 24 h. Morphological changes and induction of DNA fragmentation have revealed apoptotic effects of ceranib-2 in both cell lines. Ceranib-2 and carboplatin has shown synergism in combined treatment at 10 and 25 μM doses in H460 cells for 24 h. Ceranib-2 inhibited acid ceramidase activity by 44% at 25 µM in H460 cells. Finally, CASP3, CASP9 and BAX expressions were increased while BCL-2 expression was reduced in both cells. Our results obtained some preliminary results about the cytotoxic and apoptotic effects of ceranib-2 for the first time in NSCLC cell lines.