No abstract

Tanshinone IIA (TSIIA), a natural diterpene quinone in the traditional Chinese medicinal herb Dan-Shen (Salvia miltiorrhiza), has extensively exerted antitumor activity in cellular and animal models. However, the molecular mechanisms underlying the antitumor effects of TSIIA remain largely unknown. The in vitro effects of TSIIA on apoptosis were investigated in A549 non-small cell lung cancer (NSCLC) cells. The data showed that TSIIA significantly suppressed the proliferation of A549 cells in a dose-dependent manner, with IC50 values of 16.0±3.7 and 14.5±3.3 µM at 48 h as determined by Cell Counting Kit-8 (CCK-8) assay and clone formation assay, respectively. The change of mitochondrial morphology and the loss of mitochondrial membrane potential (MMP) were observed during the induction. Furthermore, TSIIA induced A549 cell apoptosis as confirmed by typical morphological changes, with cytochrome c release from the mitochondria and Bax translocation to the mitochondria. Caspase activity data indicated that TSIIA activated caspase-9 and caspase-3 of mitochondria-mediated apoptosis, but not caspase-8 of receptor-mediated apoptosis, which could be largely rescued by SP600125 (JNK inhibitor). Taken together, these findings provide the first evidence that TSIIA inhibits growth of NSCLC A549 cells, induces activation of JNK signaling and triggers caspase cascade apoptosis mediated by the release of cytochrome c, which provides a better understanding of the molecular mechanisms of TSIIA on lung cancer.

No abstract

Combined with VIP-ergic nerve denervation, significant nerve sprouting and NPY-ergic nerve hyperinnervation are present in a canine model of sustained AF produced by prolonged atrial pacing.

ABSTRACT. Cytochalasin B (CB) is known to inhibit a number of cancer types, but its effects on gliomas are unknown. We examined the in vitro effects of CB on the proliferation of human glioma U251 cells, as well as determined its mechanism of action. Cell proliferation was determined using CCK-8. The effect of CB on U251 cell morphology was observed under a transmission electron microscope. Cell cycle distribution was assessed using propidium iodine and Giemsa staining, and cell apoptosis was determined by annexin V-fluorescein isothiocyanate/propidium iodide. Cell cycle-related proteins were determined by Western blot. CB effectively inhibited U251 cell proliferation in a dose-and time-dependent manner. The 24, 48, 72, and 96 h IC 50 values were 6.41 x 10 -2 , 9.76 x 10 -4 , 2.57 x 10 -5 , and 2.08 x 10 -5 M, respectively. CB increased the proportion of cells in the G2/M phase in a dose-dependent manner, thus increasing the mitotic index and decreasing cdc2 and cyclin B1 protein levels. CB M CB induced apoptosis in 23.4 ± 0.5% of U251 cells (P < 0.05 vs control group). Caspase-3, -8, and -9 activities were increased after CB treatment. CB inhibited U251 glioma cell proliferation by damaging the microfilament structure. CB also induced glioma cell apoptosis, suggesting that it may be an effective therapeutic agent against gliomas.