Impact of Taurine on the proliferation and apoptosis of human cervical carcinoma cells and its mechanism.

BACKGROUND: Cervical cancer has the fourth highest incidence and mortality rate of all cancers in women worldwide; it seriously harms their physical and mental health. The aim of this study was to observe the roles and preliminary mechanism of Taurine (Tau)-induced apoptosis in cervical cancer cells. METHODS: Cells from the human cervical cancer cell line SiHa were transfected with the recombinant plasmid pEGFP-N1-MST1 (mammalian sterile 20-like kinase 1); then, the cell proliferation activity was analyzed by the MTT assay, cell apoptosis by flow cytometry, and the related protein levels by Western blotting. RESULTS: Tau inhibited the proliferation of SiHa cells and induced apoptosis in these cells (the apoptotic rate was 21.95% in the Tau 160 mmol/L group and 30% in the Tau 320 mmol/L group), upregulated the expression of the MST1 (control, 0.53; Tau 40-320 mmol/L groups, 0.84-1.45) and Bax (control, 0.45; Tau 40-320 mmol/L groups, 0.64-1.51) proteins (P < 0.01), and downregulated the expression of Bcl-2 (control, 1.28, Tau 40-320 mmol/L groups, 0.93-0.47) (P < 0.01). The overexpression of MST1 promoted the apoptosis of SiHa cells, enhanced the apoptosis-inductive effects of Tau (P < 0.01), upregulated the expression of the proapoptotic proteins p73, p53, PUMA (p53 upregulated modulator of apoptosis), and caspase-3, and promoted the phosphorylation of YAP (Yes-associated protein). CONCLUSIONS: Tau inhibited the proliferation and induced the apoptosis of cervical cancer SiHa cells. The MST1 protein plays an important role in the Tau-induced apoptosis of cervical cancer cells.

Effect of diallyl trisulfide on human ovarian cancer SKOV- 3/DDP cell apoptosis.

AIM: To investigate the effects of diallyl trisulfide (DT) on apoptosis of cisplatin (DDP)-resistant human epithelial ovarian cancer SKOV-3 cells (SKOV-3/DDP), and the role of p53 upregulated modulator of apoptosis (PUMA). METHODS: SKOV-3/DDP cells were randomly divided into control, DT, DPP and DPP+DT groups, which were treated with DT or combined DT and DDP. All cells were incubated for 48 h. and apoptosis rates were assessed by flow cytometry. mRNA and protein expression of PUMA, Bax and Bcl-2 was determined by RT-PCR and Western blot assays, respectively. RESULTS: Compared with control group, the apoptosis rates of SKOV-3/DDP cells in DT groups were obviously increased, with dose-dependence (P < 0.05), the mRNA and protein expressions of PUMA, Bax also being up-regulated (P < 0.05), while those of Bcl-2 were down-regulated (P < 0.05). Compared with DT groups, the apoptosis rate in the DDP+DT group was significantly increased (P < 0.05). After knockdown of PUMA with specific siRNA, the apoptosis rate of SKOV-3/DDP cells was obviously decreased (P < 0.05). CONCLUSION: DT can promote the apoptosis of SKOV-3/DDP cells with PUMA playing a critical role.

[Study on apoptosis of human stomach SGC-7901 cells induced by extracts of Solanum lyratum].

OBJECTIVE: To investigate the effects of extracts of Solanum lyratum (ESL) on the apoptosis of Human stomach cancer SGC-7901 cells. METHODS: Dried whole herbs of Solanum lyratum were extracted by boiling distilled water. SGC-7901 cells were randomly divided into control group, ESL-treated groups (12.5 g/L, 25 g/L, 50 g/L) and the positive control (25 mg/L DDP) group. The growth inhibitory rate was evaluated by MTT assay. Morphological changes of apoptosis were observed with fluorescence microscope. Cell apoptosis rate was determined by flow cytometry. Expressions of bcl-xl, Caspase-9 and bid mRNA were detected by semi-quantitive RT-PCR. The activity of Caspase-3 was detected by Fluorospectrophotometry. RESULTS: Compared with control group, the cell proliferation inhibitory rate and apoptosis rate of human stomach cancer SGC-7901 cells increased obviously (P < 0.05). There were obvious changes of morphology of the SGC-7901 cells as the nuclear shrinkage, chromatin condensation and margination; The expression of bcl-xl mRNA decreased obviously (P < 0.05), the expression of Caspase-9 and bid mRNA increased obviously respectively (P < 0.05), and displayed effect in a dose-dependent manner in the SGC-7901 cells of the ESL-treated groups. The activity of Caspase-3 in the SGC-7901 cells of the ESL-treated groups were higher than that of the control group significantly (P < 0.01). CONCLUSION: ESL can induce apoptosis and inhibit proliferation of the human stomach cancer SGC-7901 cells by regulating expression of bcl-xl, Caspase-9 and bid genes and strengthening the activity of Caspase-3.

[Protective effects of taurine on myocardial mitochondria and their enzyme activities in rate with severe burn].

OBJECTIVE: To investigate the effects of taurine on myocardial mitochondria and their enzyme activities in rats with severe burn. METHODS: One hundred and twenty healthy adult Wistar rats were subjected to 30% TBSA full-thickness burn. They were randomly divided into burn group (B, with intraperitoneal injection of isotonic saline), treatment group (T, with intraperitoneal injection of taurine, 200 mg/kg),with 60 rats in each group . Ten rats with sham scald were used as control (S group). The myocardial tissue samples in B and T groups were harvested at 1, 3, 6, 12, 24 and 48 postburn hours (PBH) for determination of activity respectively of succinate dehydrogenase (SDH), cytochrome oxidase (CCO), the superoxide dismutase (SOD), Ca2+ -ATPase in mitochondria, and contents of cytochrome c (Cyt c), cytochrome aa3 (Cyt aa3), malondialdehyde (MDA), and Ca2+ in mitochondria and cytoplasm . The myocardial tissue samples of controls were harvested at 1 PBH for determination of above indices. RESULTS: The activity of CCO in B group was decreased at 1 PBH , especially at 6 ,12 PBH. The activity of SDH in B group was decreased to lowest level at 6 PBH, and its value was lower than that of S group at each time point. The activity of CCO or SDH in T group was not obviously decreased, and the activity of CCO at 3, 6, 12 PBH showed significant difference compared with B group (P < 0.05). The contents of Cyt aa3 and Cyt c in B group at 3, 6, 12, 24 PBH were obviously decreased, which were significantly lower than those in T group (P < 0.05). The activity of SOD in B group at 3, 6, 12 PBH was obviously decreased, the activity of Ca2+ -ATPase at 3, 6, 12 and 24 PBH was decreased to different extent, which was significantly lower than those in T group (P < 0.05). The MDA contents in B and T groups were higher than that in S group at 3-48 PBH ,and it was highest in B group (P < 0.05). The Ca2+ content of mitochondria in B group at 1 PBH was increased (13.7 +/- 1.5), and it was (24.8 +/- 2.6), (29.7 +/- 3.1), (16.3 +/- 1.9) and (13.5 +/- 1.7) at 3, 6, 12, 24 PBH respectively,and they were all higher than that of S group (10.7 +/- 1.6, P < 0.05). The Ca2 contents of cytoplasm in group B at 3 - 24 PBH were also higher than that in S group (P < 0.05). The Ca2+ content of mitochondria in T group at 3, 6, 12, 24 PBH was (16.8 +/- 2.8), (18.7 +/- 1.9), (10.5 +/- 1.8) and (13.3 +/- 1.7)respectively, which were lower than that in B group at every time point. CONCLUSION: Taurine have protective effect on mitochondria and their enzyme activities in myocardium in rats with severe burn, and it may be attributable to improving the ability of eradicating oxygen free radicals and alleviating Ca2+ overload in the mitochondria.