Caspase-3 is Involved in The Chan-Su(CS)-induced Human Lung Adenocarcinoma(ASTC-a-1) Cell Apoptosis

Chan-Su(CS,or bufonis venenum),a traditional Chinese medicine,has many biological functions.It is mainly composed of bufotenidines,bufogenins,and etc.CS has been documented to possess functions against inflammation and cancer,and is widely employed as a therapeutic drug for many kinds of cancers in China.However,it is difficult to judge antitumor effect of agents derived from CS because of the following reasons:agents derived from CS are mixture,they are lack of observations of multiple centres,preparation process is lack of quality control standards and agents have many toxic or side effects at high dose.Apoptosis is a very important cellular event that plays a key role in pathogeny and therapy of many diseases.The mechanisms of the initiation and regulation of apoptosis are complex and diverse.Caspase family is closely connected with many apoptotic processes,while its member,caspase-3,being an important executive apoptotic molecule.To explore the inhibitory effect and mechanism of CS on human lung adenocarcinoma(ASTC-a-1),gene plasmid transfection,fluorescence emission spectra and fluorescence resonance energy transfer(FRET) were used to study the caspase-3 activation during the CS-induced human lung adenocarcinoma(ASTC-a-1) cell apoptosis.CCK-8 was used to assay the inhibition of CS on the cells viability.The dynamical emission spectra of SCAT3 were performed inside living cells expressed stably with SCAT3 after CS treatment.The cell morphology was examined and photographed by phase microscope and confocal fluorescence scanning microscope.Experimental results showed that(1) CS inhibited dose-dependently the cells viability;(2) apoptotic body was observed in some cells 6 h after CS treatment,and most of cells were in shrinkage 24 h after CS treatment;(3) The SCAT3 inside living cells were cleaved by caspase-3 2 h after CS treatment,and most of the SCAT3 was cleaved 24 h after CS treatment,and the acceptor photobleaching experiments of SCAT3 also verified these results,implying that CS activated caspase-3 which induced cell apoptosis.Therefore,caspase-3 is involved in the CS-induced cell apoptosis.