• BMB Reports
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• v.35 no.1
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• pp.116-126
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• 2002

Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.

• BMB Reports
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• v.35 no.3
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• pp.267-272
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• 2002

TNF-$\alpha$ elicits various responses including apoptosis, proliferation, and differentiation according to cell type. In neuronal PC12 cells, TNF-$\alpha$ induces moderate apoptosis while lipopolysarccaharide or trophic factor deprivation can potentiate apoptosis that is induced by TNF-$\alpha$. TNF-$\alpha$ initiates various signal transduction pathways leading to the activation of the caspase family, NF-${\kappa}B$, Jun N-terminal kinase, and p38 MAPK via the death domain that contains the TNF-$\alpha$ receptor. Inhibition of translation using cycloheximide greatly enhanced the apoptotic effect of TNF-$\alpha$. This implies that the induction of anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic Bcl-2 family member, was highly expressed in response to TNF-$\alpha$. In this study, we examined the anti-apoptotic role of p38 MAPK that is activated by TNF-$\alpha$ in neuronal PC12 cells. The phosphorylation of p38 MAPK in response to TNF-$\alpha$ slowly increased and lasted several hours in the PC12 cell and DRG neuron. This specific inhibitor of p38 MAPK, SB202190, significantly enhanced the apoptosis that was induced by TNF-$\alpha$ in PC12 cells. This indicates that the activation of p38 MAPK could protect PC12 cells from apoptosis since there is no known role of p38 MAPK in resoonse to TNF-$\alpha$ in neuron. This discovery could be evidence for the neuroprotective role of the p38 MAPK.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1548-1555
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• 2006

Bujeonghangam-tang(BHT) has been used as an anticancer agent in oriental medicine, but the mechanism by which it induces cell death in cancer cells is still unclear. To investigate cell death mechanism by BHT in cancer cells, the activities of apoptosis signaling pathway were tested in human neuroblastoma cell line LAN5. Viability of LAN5 cells was markedly decreased by treatment of the water extract of BHT in a dose-dependent manner. BHT induced cell death was confirmed as apoptosis characterized by chromatin condensation. We tested whether the water extract of BHT affects the anti-apoptotic protein such as Bcl-2 and Bcl-XL, and the pro-apoptotic protein such as Bax. Both Bcl-2 and Bcl-XL were gradually decreased but Bas was increased in a time-dependent manner after the addition of the water extract of BHT. Cleavage of Bid by activation of caspase-8 protease was also observed in LAN-5 cells by the treatment of the water extract of BHT. Taken together, these results suggest that the water extract of BHT exerts anti-cancer effects on human neuroblastoma LAN-5 cells by inducing the apoptotic death via down-regulation of anti-apoptotic proteins such as Bcl-2 and Bcl-XL, up-regulation of pro-apoptotic protein such as Bax, and activation of intrinsic caspase cascades.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.167-173
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• 2005

To investigate the possible molecular mechanism (s) of bee venom as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Bee venom treatment declined the cell growth and viability of A549 cells in a concentration-dependent manner, which was associated with induction of apoptotic cell death. Bee venom down-regulated the levels of anti-apoptotic genes such as Bcl-2 and Bcl-XS/L, however, the levels of Bax, a pro-apoptotic gene, were up-regulated. Bee venom treatment induced not only tumor suppressor p53 but also cyclin-dependent kinase inhibitor p21WAF1/CIP1 expression in a dose-dependent manner. Furthermore, bee venom treatment induced the down-regulation of telomerase reverse transcriptase mRNA and telomeric repeat binding factor expression of A549 cells, however, the levels of telomerase-associated protein-1 and c-myc were not affected. Taken together, these findings suggest that bee venom-induced inhibition of human lung cancer cell growth is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products, and bee venom may have therapeutic potential in human lung cancer.

• Journal of Life Science
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• v.18 no.6
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• pp.804-813
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• 2008

Cordyceps militaris, the Chinese medicinal fungal genus Cordyceps, is reported to possess many pharmacological activities including immunological stimulating, anti-cancer, anti-virus and anti-infection activities. However, the molecular mechanisms of C. militaris on biochemical actions in cancer have not been clearly elucidated yet. In the present study, we investigated the anti-proliferative activity of the water extract of C. militaris (WECM) in human hepatocellular carcinoma HepG2 cells. It was found that WECM could inhibit the cell growth in a dose-dependent manner, which was associated with morphological changes and apoptotic cell death such as formation of apoptotic bodies and increased populations of apoptotic sub-G1 phase. Apoptotic cell death of HepG2 cells by WECM was connected with a up-regulation of pro-apoptotic Bax expression, tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 (WAF1/CIP1). In addition, WECM treatment induced the proteolytic activation of caspase-3 and a concomitant degradation and/or inhibition of poly (ADP-ribose) polymerase (PARP), ${\beta}-catenin$ and phospholipase $(PLC)-{\gamma}1$ protein. Furthermore, caspase-3 inhibitor, z-DEVD-fmk, significantly inhibited WECM-induced apoptosis demonstrating the important role of caspase-3 in the observed cytotoxic effect. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of C. militaris.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.173-181
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• 2004

To delay the onset of apoptosis in the culture, transformed Tn 5B1-4 cells harboring anti-apoptotic genes, bcl-2 and baculovirus p35, have been established and analyzed for their anti-apoptotic ability in suspension culture using spinner flasks. In the suspension culture at agitation speeds of 100 rpm and 200 rpm, the cell growth of cell clone expressing Bcl-2 protein was much higher than other two clones and the maximum cell density of the clone was 6.0 ${\times}$ 10$^{6}$ cells/ml and 6.2 ${\times}$ 10$^{6}$ cells/ml at day three of the incubation. On the other hand, the cell growth of cell clone expressing baculovirus protein P35 was much higher than other two clones in suspension culture at agitation speed of 300 rpm and the maximum cell density of the clone was 6.1 ${\times}$ 10$^{6}$ cells/ml at day three of the incubation. Based on the pattern of genomic DNA laddering and the microscopic observation of apoptotic bodies, the more apoptotic bodies are induced in Tn 5B1-4 control cell clone at higher agitation speed. This result shows that the shear stress can be a main factor in inducing apoptosis in spinner flask culture. At low agitation speed, cell clone expressing Bcl-2 was more effective in delaying the onset of apoptosis than the cell clone expressing P35. On the other hand, at high agitation speed, cell clones expressing baculovirus P35 was more effective in delaying the onset of apoptosis than the cell clone expressing Bcl-2. Therefore, anti-apoptotic genes, bcl-2 and baculovirus p35, can playa distinct role depending on agitation speed in the suspension culture.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.759-766
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• 2004

In the present study, we investigated the effects of aqueous extract of the healthful decoction utilizing Phellinus linteus (HDPL) on the cell growth of human lung carcinoma tumor cell line A549. Exposure of A549 cells to HDPL resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometric analysis. This increase in apoptosis was associated with inhibition and/or degradation of apoptotic target proteins such as poly(ADP-ribose) polymerase (PARP), b-catenin and phospholipase C- 1 (PLC- 1) protein. HDPL treatment induced the down-regulation of anti-apoptotic Bcl-2 expression, an anti-apoptotic gene, however, the level of Bax. a pro-apoptotic gene, was increased by HDPL treatment. In addition, HDPL-induced apoptotis of A549 cells was connected with activation of caspase-3 and caspase-9 protease in a dose-dependent manner, however, the levels of inhibitor of apoptosis proteins family were remained unchanged. Taken together, these results indicated that the anti-proliferative effects of HDPL were associated with the induction of apoptotic cell death through regulation of several major growth regulatory gene products such as Bcl-2 family expression and caspase protease activity, and HDPL may have therapeutic potential in human lung cancer.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.91-102
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• 2012

Bcl-2 protects tumor cells from the apoptotic effects of various anti-neoplastic agents. Increased expression of Bcl-2 has been associated with a poor response to chemotherapy in various malignancies, including leukemia. Hence, bypassing the resistance conferred by anti-apoptotic factors such as Bcl-2 represents an attractive therapeutic strategy against cancer cells, including leukemic cells. This study was undertaken to examine whether the anticancer drug, cisplatin and the synthetic chenodeoxycholic acid (CDCA) derivative, HS-1200 show anti-tumor activity in U937 and U937/Bcl-2 cells. Viability assays revealed that HS-1200 overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells. Various apoptosis assessment assays further demonstrated that HS-1200 overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells by inducing apoptosis. In addition HS-1200, but not cisplatin, overcomes the anti-apoptotic effects of Bcl-2 in Bcl-2 over-expressing human leukemic cells (U937/Bcl-2 cells). Notably, we observed that the HS-1200-induced formation of mature promyelocytic leukemia (PML) nuclear bodies (NBs) correlates with a suppression of the anti-apoptotic effects of Bcl-2 in human leukemic cells over-expressing this protein (U937/Bcl-2 cells). Furthermore, HS-1200 was found to induce the association between PML and SUMO-1, Daxx, Sp100, p53 or CBP in the aggregated PML-NBs of U937/Bcl-2 cells. Thus, PML protein and the formation of mature PML-NBs could be considered as therapeutic targets that may help to bypass the resistance to apoptosis conferred by Bcl-2. Elucidating the exact mechanism by which PML regulates Bcl-2 will require further work.

• Journal of Life Science
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• v.25 no.1
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• pp.93-100
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• 2015

Pachymic acid (PA) is a lanostane-type triterpenoid derived from the Poria cocos mushroom. Several beneficial biological features of PA provide medicine with a wide variety of valuable effects, such as anticancer and anti-inflammatory activity; it also has antioxidant effects against oxidative stress. Nonetheless, the biological properties and mechanisms that produce this anti-cancer action of PA remain largely undetermined. In this study, we investigated the pro-apoptotic effects of PA in T24 human bladder cancer cells. It was found that PA could inhibit the cell growth of T24 cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies and chromatin condensation and accumulation of cells in the sub-G1 phase. The induction of apoptotic cell death by PA was connected with an up-regulation of pro-apoptotic Bax and Bad protein expression and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL proteins, and inhibition of apoptosis family proteins. In addition, apoptosis-inducing concentrations of PA induced the activation of caspase-9, an initiator caspase of the mitochondrial-mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. PA also induced apoptosis via a death receptor-mediated extrinsic pathway by caspase-8 activation, resulting in the truncation of Bid and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. Taken together, the present results suggest that PA may be a potential chemotherapeutic agent for the control of human bladder cancer cells.

• YAKHAK HOEJI
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• v.56 no.3
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• pp.173-179
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• 2012

Saussurea lappa (SL) and major compounds, sesquiterpene lactones, have been suggested to possess various biological effects, including anti-tumor, anti-ulcer, anti-inflammatory, anti-viral and cardiotonic activities. Therefore, the ethanol extract of Saussurea lappa root (ESL) is studied for the mechanism of its action in apoptotic pathway. ESL-treated cells manifested nuclear condensation, and fragmentation. ESL also triggered the mitochondrial apoptotic pathway, as indicated by a change in Bax/Bcl2 ratio and caspase-9/-3 activation. ESL induced p38 MAPK/JNK, p53, and ASK1 phosphorylation. ROS scavenger reversed ESL-induced apoptotic cell death via inhibition of caspase-3 and p38 MAPK/JNK phosphorylation. These results suggest that ESL induced apoptosis in HepG2 cells through the ROS-p38/JNK pathway.