Apoptosis caspase cascade activated by norcycloartocarpin.

The augmented level of cleaved caspase-9, an initiator caspase of apoptosis cascade, was demonstrated in lung cancer (A) A549 and (B) H460 cells cultured with 25–50 μM norcycloartocarpin (NCAC) for 24 h. (C) and (D) NCAC at 50 μM obviously up-regulated active form of caspase-3, cleaved caspase-3, in lung cancer A549 and H460 cells, respectively. Moreover, the enzymatic function of cleaved caspase-3 was also evidenced with the conversion of PARP to cleaved PARP in NCAC-treated cells. The alteration of Bcl-2 family proteins including reduced Bcl-2 and accumulated Bax associating with the up-regulation of p53 was notified in both (E, G) A549 and (F, H) H460 lung cancer cells incubated with NCAC at 50 μM for 24 h. The restoration of p53 and down-regulation of Bcl-2 was also presented in the cells after culture with 25 μM NCAC. Data are represented as mean ± SEM from three independent experiments. *p < 0.05 versus non-treated control cells.