No abstract

Benzyl isothiocyanates (BITC), a member of the isothiocyanate (ITC) family, inhibits cell growth and induces apoptosis in many types of human cancer cell lines. The present study investigated mechanisms underlying BITC-induced apoptosis in A375.S2 human melanoma cancer cells. To observe cell morphological changes and viability, flow cytometric assays, cell counting, and a contrast-phase microscopic examination were carried out in A375.S2 cells after BITC treatment. Cell cycle distribution and apoptosis were assessed with the analysis of cell cycle by flow cytometric assays, DAPI staining, propidium iodide (PI), and annexin V staining. Apoptosis-associated factors such as reactive oxygen species (ROS) formation, loss of mitochondrial membrane potential (ΔΨ(m)), intracellular Ca(2+) release, and caspase-3 activity were evaluated by flow cytometric assays. Abundance of cell cycle and apoptosis associated proteins was determined by Western blotting. AIF and Endo G expression was examined by confocal laser microscope. Results indicated that (1) BITC significantly reduced cell number and induced cell morphological changes in a dose-dependent manner in A375.S2 cells; (2) BITC induced arrest in cell cycle progression at G(2)/M phase through cyclin A, CDK1, CDC25C/Wee1-mediated pathways; (3) BITC induced apoptosis and increased sub-G(1) population; and (4) BITC promoted the production of ROS and Ca(2+) and loss of ΔΨ(m) and caspase-3 activity. Furthermore, BITC induced the down-regulation of Bcl-2 expression and induced up-regulation of Bax in A375.S2 cells. Moreover, BITC-induced cell death was decreased after pretreatment with N-acetyl-l-cysteine (NAC, a ROS scavenger) in A375.S2 cells. In conclusion, the results showed that BITC promoted the induction of G(2)/M phase arrest and apoptosis in A375.S2 human melanoma cells through ER stress- and mitochondria-dependent and death receptor-mediated multiple signaling pathways. These data suggest that BITC has potential as an agent for the treatment of melanoma.

Phytochemicals have been used as potential chemopreventive or chemotherapeutic agents. However, there are data suggesting a mutagenic effect of some phytochemicals. We hypothesized that safrole would have anticancer effects on human oral squamous cell carcinoma HSC-3 cells. Safrole decreased the percentage of viable HSC-3 cells via induction of apoptosis by an increased level of cytosolic Ca(2+) and a reduction in the mitochondrial membrane potential (ΔΨ(m)). Changes in the membrane potential were associated with changes in the Bax, release of cytochrome c from mitochondria, and activation of downstream caspases-9 and -3, resulting in apoptotic cell death. In vivo studies also showed that safrole reduced the size and volume of an HSC-3 solid tumor on a xenograft athymic nu/nu mouse model. Western blotting and flow cytometric analysis studies confirmed that safrole-mediated apoptotic cell death of HSC-3 cells is regulated by cytosolic Ca(2+) and by mitochondria- and Fas-dependent pathways.

The role of bronchoscopic management in post-tuberculosis tracheobronchial stenosis is not well defined. To investigate the role of bronchoscopic intervention, including silicone stenting, in the management of post-tuberculosis tracheobronchial stenosis, the current retrospective study was conducted at a tertiary referral hospital.Under rigid bronchoscopy, 80 patients underwent ballooning, neodymium-yttrium aluminium garnet laser resection and/or bougienation as first-line methods of airway dilatation between January 2000 and December 2003 inclusive, and were followed for a median of 41 months.Silicone stents were required in 75 out of 80 (94%) patients to maintain airway patency. Bronchoscopic intervention provided immediate symptomatic relief and improved lung function in 88% of the patients. After airway stabilisation, stents were removed successfully in 49 out of 75 (65%) patients at a median of 14 months post-insertion. Three patients out of 75 (4%) eventually underwent surgical management. Acute complications included: excessive bleeding (n51); pneumothorax (n55); and pneumomediastinum without mortality (n52). Stent-related late complications, such as migration (51%), granuloma formation (49%), mucostasis (19%) and restenosis (40%), were controllable during a median follow-up of 41 months.In conclusion, bronchoscopic intervention, including silicone stenting, could be a useful and safe method for treating post-tuberculosis tracheobronchial stenosis.

To investigate the effects of ellagic acid on the growth inhibition of TSGH8301 human bladder cancer cells in vitro, cells were incubated with various doses of ellagic acid for different time periods. The phase-contrast microscope was used for examining and photographing the morphological changes in TSGH8301 cells. Flow cytometric assay was used to measure the percentage of viable cells, cell cycle distribution, apoptotic cells, ROS, mitochondrial membrane potential (ΔΨm), Ca(2+) , caspase-9 and -3 activities in TSGH8301 cells after exposure to ellagic acid. Western blotting was used to examine the changes of cell cycle and apoptosis associated proteins levels. Results indicated that ellagic acid induced morphological changes, decreased the percentage of viable cells through the induction of G0/G1 phase arrest and apoptosis, and also showed that ellagic acid promoted ROS and Ca(2+) productions and decreased the level of ΔΨm and promoted activities of caspase-9 and -3. The induction of apoptosis also confirmed by annexin V staining, comet assay, DAPI staining and DNA gel electrophoresis showed that ellagic acid induced apoptosis and DNA damage in TSGH8301 cells. Western blotting assay showed that ellagic acid promoted p21, p53 and decreased CDC2 and WEE1 for leading to G0/G1 phase arrest and promoting BAD expression, AIF and Endo G, cytochrome c, caspase-9 and -3 for leading to apoptosis in TSGH8301 cells. On the basis of these observations, we suggest that ellagic acid induced cytotoxic effects for causing a decrease in the percentage of viable cells via G0/G1 phase arrest and induction of apoptosis in TSGH8301 cells.