Fused Polypeptide with DEF Induces Apoptosis of Lung Adenocarcinoma Cells

To analyze the effects of a new unknown peptide DEF on the growth of tumor cells, a fused polypeptideTAT-DV1-DEF was designed and synthesized. The lung adenocarcinoma cell line GLC-82 treated with TATDV1-DEF was analyzed with a cell counting kit 8, and the location of polypeptides in cells was observed underlaser confocal microscopy. The efficiency of polypeptide transfection and changes in nuclear morphology wereanalyzed by flow cytometry and fluorescence microscopy, respectively. Finally, the mechanism of tumor cellgrowth inhibition was evaluated by Western blotting. We found that TAT-DV1-DEF could significantly inhibitthe growth of the lung adenocarcinoma cell line GLC-82, but not the normal human embryonic kidney cellline HEK-293. Polypeptides were found to be mostly localized in the cytoplasm and some mitochondria. Theefficiency of polypeptide transfection in the two cell types was approximately 99%. Apoptotic nuclei were observedunder fluorescence microscopy upon treatment with polypeptides and DAPI staining. Western blot analysesindicated that the polypeptide inhibition of tumor cell growth was apoptosis dependent. In the present study,we demonstrated that fused polypeptides could induce apoptosis of the lung adenocarcinoma cell line GLC-82,indicating that the new unknown peptide DEF has antitumor effects.