• Journal of Life Science
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• v.19 no.11
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• pp.1581-1590
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• 2009

Hizikia fusiforme is a kind of brown edible seaweed that mainly grows in the temperate seaside areas of the northwest pacific, including Korea, Japan and China, and has been widely used as a health food for hundreds of years. Recently, H. fusiforme has been known to exert pharmacological activities including antioxidant, antimutagenic and anticoagulant activities. However, the molecular mechanisms of H. fusiforme in malignant cells have not been clearly elucidated yet. In this study, the effects of ethyl alcohol extract of H. fusiforme (EAHF) on the anti-proliferative effects of MDA-MB-231 and MCF-7 human breast cancer cells were investigated. EAHF treatment resulted in a concentration-dependent growth inhibition by including apoptosis in MDA-MB-231 cells and G1 phase arrest in MCF-7 cells, which could be proved by MTT assay, DAPI staining, agarose gel electrophoresis and flow cytometry analysis. In MDA-MB-231 cells, the increase in apoptosis induced by EAHF treatment correlated with up-regulation of pro-apoptotic Bax expression. EAHF treatment induced the proteolytic activation of caspase-3 and caspase-9, and a concomitant inhibition of poly (ADP-ribose) polymerase, $\beta$-catenin, phospholipase-${\gamma}1$ protein and DNA fragmentation factor 45/inhibitor of caspase-activated DNase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. fusiforme.

• The Journal of Internal Korean Medicine
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• v.28 no.3
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• pp.473-491
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• 2007

Objectives : This study was designed to investigate the antiproliferative activity of the water extract of Samgibopae-tang (SGBPT) in NCI-H460 and A549 non-small-cell lung cancer cell lines Methods : In this study, we measured the subsistence, form of NCI-H460 and A549 non-small-cell lung cancer cell by hemocytometer and DAPI staining. In each cell, we analyzed DNA fragmentation. reverse transcription-polymerase chain reaction and measured activity of caspase-3, caspase-8 and caspase-9. Results and Conclusions : We found that exposure of A549 cells to SGBPT resulted in growth inhibition in a dose-dependent manner. butSGBPT did not affect the growth of NCI-H460 cells. The antiproliferative effect by SGBPT treatment in A549 cells was associated with morphological changes. SGBPT treatment partially induced the expression of DR5 cells and the expression of Faswas markedly increased in both transcriptional and translational levels in A549 cells. SGBPT treatment partially induced the expression of Bcl-2, Bcl-XL and the expression of Bid was markedly decreased in translational levels in A549 cells. However, SGBPT treatment did not affect the expression of IAP family in A549 orNCI-H460 cells. SGBPT treatment partially induced the expression of caspase-3, caspase-8, caspase-9 activity which markedly increased in a dose-dependent manners in A549 cells. The fragmental development of PARP and ${\beta}$-catenin protein was observed in A549 cells by SGBPT treatment. SGBPT treatment induced the expression of PLC-${\gamma}1$ protein which decreased in A549 cells. SGBPT treatment partially induced the expression of DFF45/ICAD which markedly increased in a dose-dependent manner in A549 cells. Taken together. these findings suggested that SGBPT-induced inhibition of human lung carcinoma did not affect NCI-H460 cell growth. However, SGBPT-induced inhibition of human lung carcinoma A549 cell growth was associated with the induction of death receptor and mitochondrial pathway. The results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of SGBPT.

• Journal of Life Science
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• v.19 no.11
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• pp.1529-1537
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• 2009

To elucidate further the antitumor effects of a natural L-arginine analogue, L-canavanine, the mechanism underlying apoptogenic activity of L-canavanine and its modulation by protein tyrosine kinase $p56^{lck}$ was investigated in human Jurkat T cells. When the cells were treated with 1.25 to 2.5 mM L-canavanine for 36 h, several apoptotic events including mitochondrial membrane potential (${\Delta\Psi}m$) loss, activation of caspase-9, -3, -8, and -7, poly (ADP-ribose) polymerase (PARP) degradation, and DNA fragmentation were induced without alteration in the levels of Fas or FasL. These apoptotic changes were more significant in $p56^{lck}$-deficient Jurkat clone JCaM1.6 than in $p56^{lck}$-positive Jurkat clone E6.1. The L-canavanine-induced apoptosis observed in $p56^{lck}$-deficient JCaM1.6 cells was significantly reduced by introducing $p56^{lck}$ gene into JCaM1.6 cells by stable transfection. Treatment of JCaM1.6/lck cells with L-canavanine caused a transient 1.6-fold increase in the kinase activity of $p56^{lck}$. Both FADD-positive wild-type Jurkat T cell clone A3 and FADD-deficient Jurkat T cell clone I2.1 exhibited a similar susceptibility to the cytotoxicity of L-canavanine, excluding involvement of Fas/FasL system in triggering L-canavanine-induced apoptosis. The L-canavanine-induced apoptotic sub-$G_1$ peak and activation of caspase-3, -8, and -7 were abrogated by pan-caspase inhibitor (z-VAD-fmk), whereas L-canavanine-induced activation of caspase-9 was not affected. These results demonstrated that L-canavanine caused apoptosis of Jurkat T cells via the loss of ${\Delta\Psi}m$, and the activation of caspase-9, -3, -8, and -7, leading to PARP degradation, and that the $p56^{lck}$ kinase attenuated the ${\Delta\Psi}m$ loss and activation of caspases, and thus contributed as a negative regulator to L-canavanine-induced apoptosis.