• The Journal of Internal Korean Medicine
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• v.35 no.3
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• pp.317-331
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• 2014

Objectives: The root of Platycodon grandiflorum (PG) has been known to possess a range of pharmacological activities including anti-cancer, anti-inflammatory, and anti-oxidant effects. The present study was designed to investigate whether or not PG-induced cell death was connected with autophagy and apoptosis in NCI-H460 human lung cancer cells. Methods: Effects on the cell viability and apoptotic activity were quantified using MTT assays and flow cytometry analysis, respectively. Protein activation was measured by immunoblotting. Autophagy was measured by LC3 immunofluorescence and immunoblotting. ROS production and loss of mitochondria membrane potential (MMP) were checked with flow cytometry analysis. Results: Following exposure to PG, NCI-H460 cell proliferation decreased simultaneously inducing autophagic vacuoles and up-regulation of microtubule-associated protein 1 light chain 3 and beclin-1 protein expressions. Interestingly, pre-treated with autophagy inhibitors, 3-methyladenin or bafilomycin A1 further triggered reduction of cell viability. PG treatment also induced apoptosis that was related modulation of Bcl-2 family proteins, death receptors and activation of caspases. In addition, PG stimulation clearly enhanced loss of MMP and reactive oxygen species (ROS) generation. Conclusions: Our results suggest that PG elicited both autophagy and apoptosis by increasing loss of MMP and ROS production. PG induced-autophagy may play a cell protective role.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.756-766
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• 2005

The signaling mechanism underlying aburatubolactam C-induced FasL upregulation was investigated in human Jurkat T cells. After treatment with aburatubolactam C, the src-family PTKs $p56^{lck}\;and\;p59^{fyn}$, and MAP kinases ERK2 and JNK1, were activated prior to FasL upregulation; Both $p56^{lck}\;and\;p59^{fyn}$ were directly activated 2.4- and 2.2-fold, respectively, in vitro by aburatubolactam C. The aburatubolactam C-induced cellular changes, including the activation of ERK2 and INK1, and FasL upregulation, were completely prevented by the PTK inhibitor genistein. The activation of protein kinase C (PKC$\delta,\;\epsilon\;and\;\mu$ was also induced following aburatubolactam C treatment. Although the activation of $p56^{lck}$ and tyrosine phosphorylation of the cellular proteins were not blocked by the PKC inhibitor GFl09203X, the activation of ERK2 was completely abrogated, along with a detectably enhanced JNK1 activation; FasL upregulation, and apoptosis. However, the FasL upregulation and apoptosis were significantly inhibited by the PKC activator PMA, with a remarkable increase in the ERK2 activation. The cytotoxic effect of aburatubolactam C was reduced in the presence of the anti-Fas neutralizing antibody ZB-4. Although ectopic expression of Bcl-2 failed to completely block the cytotoxicity of aburatubolactam C, it was clearly suppressed. The c-Fos mRNA expression was upregulated in a biphasic manner, where the second phasic expression overlapped with the FasL upregulation. Accordingly, these results demonstrate that aburatubolactam C-induced apoptosis is exerted, at least in part, by FasL upregulation dictated by activation of the PTK ($p56^{lck}\;and\;p59^{fyn}$) /JNKI pathway, which is negatively affected by the concurrent activation of the PKC/ERK2 pathway proximal to PTK activation.

• Journal of Life Science
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• v.26 no.6
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• pp.663-672
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• 2016

The Cnidium monnieri (L.) Cusson is an annual plant distributed in China and Korea. The fruit of C. monnieri is used as a medicinal herb that is effective for the treatment of carbuncle and pain in female genitalia. However, the anti-cancer effects of CME have not yet been reported. In this study, we assessed the apoptotic effects and cell cycle arrest effects of ethanol extracts from C. monnieri on HCT116 colon cancer cells. The results of an MTT assay and LDH assay demonstrated a decrease in cell viability and the cytotoxic effects of CME. In addition, the number of apoptotic body and the apoptotic rate were increased in a dose-dependent manner through Hoechst 33342 staining and Annexin V-PI double staining. In addition, cell cycle arrest occurred at the G1 phase by CME. Protein kinase B (Akt) plays an important role in cancer cell survival, growth, and division. Akt down-regulates apoptosis-mediated proteins, such as mammalian target of rapamycin (mTOR), p53, and Glycogen Synthase kinase-3β (GSK-3β). CME could regulate the expression levels of p-Akt, p-mTOR, p-GSK-3β, Bcl-2 family members, caspase-3, and PARP. Furthermore, treatment with CME, LY294002 (PI3K/Akt inhibitor), BIO (GSK-3β inhibitor), and Rapamycin (mTOR inhibitor) showed that apoptotic effects occurred through the regulation of the AKT/mTOR/GSK-3β signaling pathway. Our results demonstrated CME could induce apoptosis and cell cycle arrest in HCT116 colon cancer cells.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.73-81
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• 2023

Sirtuins (SIRTs) belong to the nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase family. They are key regulators of cellular and physiological processes, such as cell survival, senescence, differentiation, DNA damage and stress response, cellular metabolism, and aging. SIRTs also influence carcinogenesis, making them potential targets for anticancer therapeutic strategies. In this study, we investigated the anticancer properties and underlying molecular mechanisms of a novel SIRT1 inhibitor, MHY2251, in human colorectal cancer (CRC) cells. MHY2251 reduced the viability of various human CRC cell lines, especially those with wild-type TP53. MHY2251 inhibited SIRT1 activity and SIRT1/2 protein expression, while promoting p53 acetylation, which is a target of SIRT1 in HCT116 cells. MHY2251 treatment triggered apoptosis in HCT116 cells. It increased the percentage of late apoptotic cells and the sub-G1 fraction (as detected by flow cytometric analysis) and induced DNA fragmentation. In addition, MHY2251 upregulated the expression of FasL and Fas, altered the ratio of Bax/Bcl-2, downregulated the levels of pro-caspase-8, -9, and -3 proteins, and induced subsequent poly(ADP-ribose) polymerase cleavage. The induction of apoptosis by MHY2251 was related to the activation of the caspase cascade, which was significantly attenuated by pre-treatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, MHY2251 stimulated the phosphorylation of c-Jun N-terminal kinase (JNK), and MHY2251-triggered apoptosis was blocked by pre-treatment with SP600125, a JNK inhibitor. This finding indicated the specific involvement of JNK in MHY2251-induced apoptosis. MHY2251 shows considerable potential as a therapeutic agent for targeting human CRC via the inhibition of SIRT1 and activation of JNK/p53 pathway.

• Journal of Acupuncture Research
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• v.21 no.2
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• pp.41-55
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• 2004

Objective : To investigate the possible molecular mechanism (s) of melittin as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Methods : Growth inhibitory study, flow cytometry analysis, SDS-polyacrylamide gel electrophoresis and Western blot analysis, RT-PCR and in vitro caspases activity assay were performed. Results : Melittin treatment declined the cell viability of A549 cells in a concentration-dependent manner, which was associated with induction of apoptotic cell death. Melittin treatment down-regulated the levels of Bcl-XS/L mRNA and protein expression of A549 cells, an anti-apoptotic gene, however, the those of Bax, a pro-apoptotic gene, were up-regulated. Melittin induced the proteolytic cleavage and activation of caspase-3 and caspase-9 protease in a dose-dependent manner without alteration of inhibitor of apoptosis proteins family and Akt expression. Western blot analysis and RT-PCR data revealed that the levels of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 were also remained unchanged. Conclusions : Taken together, these findings suggest that melittin-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 melittin may have therapeutic potential in human lung cancer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.714-720
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• 2008

Cordyceps militaris is a medicinal fungus which has been used for patient suffering from cancer in Oriental medicine. It was previously reported that C. militaris extracts are capable of inhibiting tumor growth and inducing apoptosis; however, the anti-poliferative effects of human cancer cells have been poorly understood. In this study, to elucidate the anti-cancer mechanisms of human cancer cells by treatment with aqueous extract of C. militaris (AECM), we investigated the anti-proliferative effects of AECM in human hepatocarcinoma Hep3B cells. AECM treatment inhibited the growth of Hep3B cells and induced the apoptotic cell death in a concentration-dependent manner such as formation of apoptotic bodies and increased populations of apoptotic-sub G1 phase. The induction of apoptosis by AECM was connected with a proteolytic activation of caspase-3 and caspase-8. and concomitant degradation of poly (ADP-ribose) polymerase (PARP) and ${\beta}$-catenin proteins. Furthermore, caspase-3 inhibitor, z-DEVD-fmk, significantly inhibited AECM-induced apoptosis demonstrating the important role of caspase-3 in the bserved cytotoxic effect. Taken together, these findings suggest that AECM-induced inhibition of human hepatocarcinoma cell proliferation is associated with the induction of apoptotic cell death via activation of caspase-3 and C. militaris may have therapeutic potential in human cancer.

• Journal of Life Science
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• v.29 no.4
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• pp.410-420
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• 2019

Citrus unshiu peel extracts possess a variety of beneficial effects, and studies on their anticancer activity have been reported. However, the exact mechanisms underlying this activity remain unclear. In the current study, the apoptotic effect of ethanol extract of C. unshiu peel (EECU) on human breast adenocarcinoma MDA-MB-231 cells and related mechanisms were investigated. The results showed that the survival rate of MDA-MB-231 cells treated with EECU was significantly inhibited in a concentration-dependent manner, which was associated with the induction of apoptosis. EECU-induced apoptosis was associated with the activation of caspase-8 and caspase-9, which initiate extrinsic and intrinsic apoptosis pathways, respectively, and caspase-3, a representative effect caspase. EECU suppressed the expression of the inhibitor of apoptosis family of proteins, leading to an increased Bax/Bcl-2 ratio and proteolytic degradation of poly (ADP-ribose) polymerase. EECU also enhanced the loss of the mitochondrial membrane potential and cytochrome c release from the mitochondria to the cytosol, along with truncation of Bid. In addition, EECU activated AMP-activated protein kinase (AMPK), and compound C, an AMPK inhibitor, significantly weakened EECU-induced apoptosis and cell viability reduction. Furthermore, EECU promoted the generation of reactive oxygen species (ROS), which acted as upstream signals for AMPK activation as pretreatment of cells, with the antioxidant N-acetyl cysteine reversing both EECU-induced AMPK activation and apoptosis. Collectively, these findings suggest that EECU inhibits MDA-MB-231 adenocarcinoma cell proliferation by activating intrinsic and extrinsic apoptotic pathways, which was mediated through ROS/AMPK-dependent pathways.