Emission spectral analysis of caspase-3 activation during artesunate (ART)-induced apoptosis of human lung adenocarcinoma cell

Abstract

Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. Artemisinin-derivative combination chemotherapy is recommended by WHO since it acts rapidly and is well tolerated and particularly effective. In present investigation, we used CKK-8 assay to assess the inhibitory effects of ART on human lung adenocarcinoma (ASTC-a-1) cells. Apoptotic activity of ART in ASTC-a-1 cells was detected by means of nuclear staining with Hoechst33258. In order to monitor the activity of caspase-3 during ART-induced ASTC-a-1 cells apoptosis, the dynamical emission spectra of SCAT3, a FRET plasmid based on GFPs, were performed inside living cell expressed stably with SCAT3 after ART treatment. The results showed that (1) ART could inhibit ASTC-a-1 cells proliferation in a dose-dependent manner; (2) chromatin condensation was observed after ART treatment for 48 h; (3) the SCAT3 inside living cells were cleaved after ART treatment for 48 h, implying that caspase-3 was involved in the ART-induced apoptosis.