To explore the toxicity and cellular uptake of the self-synthesized second mitochondria-derived activator of caspase (SMAC) mimetic TP-WY-1345 polypeptide and its radiosensitizing effect on non-small cell lung cancer (NSCLC).
Methods:A fluorescence microscope was used to observe the uptake efficiency of TP-WY-1345 by human NSCLC cells H1299. Toxicity of the TP-WY-1345 peptide in normal cells was examined in human embryonic lung fibroblasts MRC5. CCK-8 and clone formation experiments were performed to detect the radiosensitizing effect of TP-WY-1345 in the H1299 cells. The AutoDock Vina simulation software was employed to predict the binding efficiency of TP-WY-1345 to the inhibitor of apoptosis proteins (IAPs). Moreover, Western blot and qPCR experiments were carried out to determine the protein and gene expressions, and the flow cytometry (FCM) technique was used to detect the apoptosis level under different conditions.
Results:TP-WY-1345 can be self-synthesized, and significant green fluorescence was observed in H1299 2 h and 6 h after incubation with TP-WY-1345. The cell counting and CCK-8 results showed that 10 μmol/L and 20 μmol/L TP-WY-1345 did not produce a significant toxic effect on the MRC5 cells (P > 0.05). Compared with the single ionizing radiation group, the cell viability and clone formation of H1299 cells were significantly inhibited after treatment with TP-WY-1345 at a concentration of 50 μmol/L (P