• Tuberculosis and Respiratory Diseases
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• v.75 no.1
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• pp.9-17
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• 2013

Background: In cancer cells, autophagy is generally induced as a pro-survival mechanism in response to treatment-associated genotoxic and metabolic stress. Thus, concurrent autophagy inhibition can be expected to have a synergistic effect with chemotherapy on cancer cell death. Monensin, a polyether antibiotic, is known as an autophagy inhibitor, which interferes with the fusion of autophagosome and lysosome. There have been a few reports of its effect in combination with anticancer drugs. We performed this study to investigate whether erlotinib, an epidermal growth factor receptor inhibitor, or rapamycin, an mammalian target of rapamycin (mTOR) inhibitor, is effective in combination therapy with monensin in non-small cell lung cancer cells. Methods: NCI-H1299 cells were treated with rapamycin or erlotinib, with or without monensin pretreatment, and then subjected to growth inhibition assay, apoptosis analysis by flow cytometry, and cell cycle analysis on the basis of the DNA contents histogram. Finally, a Western blot analysis was done to examine the changes of proteins related to apoptosis and cell cycle control. Results: Monensin synergistically increases growth inhibition and apoptosis induced by rapamycin or erlotinib. The number of cells in the sub-$G_1$ phase increases noticeably after the combination treatment. Increase of proapoptotic proteins, including bax, cleaved caspase 3, and cleaved poly(ADP-ribose) polymerase, and decrease of anti-apoptotic proteins, bcl-2 and bcl-xL, are augmented by the combination treatment with monensin. The promoters of cell cycle progression, notch3 and skp2, decrease and p21, a cyclin-dependent kinase inhibitor, accumulates within the cell during this process. Conclusion: Our findings suggest that concurrent autophagy inhibition could have a role in lung cancer treatment.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7069-7074
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• 2013

Programmed cell death is a basic cellular process that is critical to maintaining tissue homeostasis. In contrast to apoptosis, necrosis was previously regarded as an unregulated and uncontrollable process. However, as research has progressed, necrosis, also known as necroptosis or programmed necrosis, is drawing increasing attention, not least becasu of its possible impications for cancer research. Necroptosis exhibits a unique signaling pathway that requires the involvement of receptor interaction protein kinases 1 and 3 (RIP1 and RIP3), mixed lineage kinase domain-like (MLKL), and phosphoglycerate mutase 5 (PGAM5) and can be specifically inhibited by necrostatins. Not only does necroptosis serve as a backup cell death program when apoptosis is inhibited, but it is now recognized to play a pivotal role in regulating various physiological processes and the pathogenesis of a variety of human diseases such as ischemic brain injury, immune system disorders and cancer. The control of necroptosis by various defined trigger factors and signaling pathways now offers the opportunity to target this cellular process for therapeutic purposes. The purpose of this paper is to review current findings concerning the connections between various trigger factors and the RIP1/RIP3 signaling pathway as it relates to necroptosis.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.417-423
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• 2018

Extracellular interleukin 1 alpha (IL-$1{\alpha}$) released from keratinocytes is one of the endpoints for in vitro assessments of skin irritancy. Although cells dying via primary skin irritation undergo apoptosis as well as necrosis, IL-$1{\alpha}$ is not released in apoptotic cells. On the other hand, active secretion has been identified in interleukin-1 receptor antagonist (IL-1ra), which was discovered to be a common, upregulated, differentially-expressed gene in a microarray analysis performed with keratinocytes treated using cytotoxic doses of chemicals. This study examined whether and how IL-1ra, particularly extracellularly released IL-1ra, was involved in chemically-induced keratinocyte cytotoxicity and skin irritation. Primary cultured normal adult skin keratinocytes were treated with cytotoxic doses of chemicals (hydroquinone, retinoic acid, sodium lauryl sulfate, or urshiol) with or without recombinant IL-1ra treatment. Mouse skin was administered irritant concentrations of hydroquinone or retinoic acid. IL-1ra (mRNA and/or intracellular/extracellularly released protein) levels increased in the chemically treated cultured keratinocytes with IL-$1{\alpha}$ and IL-$1{\beta}$ mRNAs and in the chemically exposed epidermis of the mouse skin. Recombinant IL-1ra treatment significantly reduced the chemically-induced apoptotic death and intracellular/extracellularly released IL-$1{\alpha}$ and IL-$1{\beta}$ in keratinocytes. Collectively, extracellular IL-1ra released from keratinocytes could be a compensatory mechanism to reduce the chemically-induced keratinocyte apoptosis by antagonism to IL-$1{\alpha}$ and IL-$1{\beta}$, suggesting potential applications to predict skin irritation.

• YAKHAK HOEJI
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• v.53 no.4
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• pp.184-188
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• 2009

Fluorouracil (5-FU) is one of the most widely used chemotherapeutic drugs in the treatment of advanced colorectal cancer patients. Capsaicin (N-vanillyl-8-methyl-alpha-nonenamide), a spicy component of hot pepper, is a homovanillic acid derivative that preferentially induces cancer cells to undergo apoptosis. The purpose of the present study is to examine whether capsaicin enhances the anticancer effect of 5-fluorouracil in HT-29 human colon cancer cells by inducing apoptosis, and whether PPARgamma is involved in the capsaicin action in combination treatment with 5-FU. Treatment of the cells with either 5-FU or capsaicin alone for 48 h had little effect on the cell viability up to $50{\mu}M$ concentration, whereas co-treatment of the cells with capsaicin in the presence of 5-FU for 48 h significantly decreased the cell viability in a concentration-dependent manner. In addition, caspase-3 activity, a marker enzyme for apoptosis, was significantly increased by the combined treatment with 5-FU and capsaicin compared to the 5-FU or capsaicin alone treatment. Also, treatment with troglitazone, a peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) agonist, further enhanced the effect of the combination treatment on the cell viability and caspase-3 activity, and bisphenol A diglycidyl ether (BADGE), a $PPAR{\gamma}$ antagonist, blocked the effect of the combination treatment. These results suggest that the combination treatment of HT-29 cells with 5-FU and capsaicin induces apoptotic cell death at relatively low concentration than each drug alone, and the combination treatment may be associated with the $PPAR{\gamma}$ pathway activation.

• Journal of Life Science
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• v.26 no.4
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• pp.431-438
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• 2016

The tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is considered a promising anticancer agent due to its unique ability to induce cancer cell death having only negligible effects on normal cells. However, many cancer cells tend to be resistant to TRAIL. In this study, we investigated the effects and molecular mechanisms of sodium butyrate (SB), a histone deacetylase inhibitor, in sensitizing TRAIL-induced apoptosis in 5637 human bladder cancer cells. Our results indicated that co-treatment with SB and TRAIL significantly increased the apoptosis induction, compared with treatment with either agent alone. Co-treatment with SB and TRAIL effectively increased the cell-surface expression of death receptor (DR) 5, but not DR4, which was associated with the inhibition of cellular Fas-associated death domain (FADD)-like interleukin-1β-converting enzyme (FLICE) inhibitory protein (c-FLIP). Furthermore, the activation of caspases (caspase-3, -8 and -9) and degradation of poly(ADP-ribose) were markedly increased in 5637 cells co-treated with SB and TRAIL; however, the synergistic effect was perfectly attenuated by caspase inhibitors. We also found that combined treatment with SB and TRAIL effectively induced the expression of pro-apoptotic Bax, cytosolic cytochrome c and cleave Bid to truncated Bid (tBid), along with down-regulation of anti-apoptotic Bcl-xL expression. These results collectively suggest that a combined regimen of SB plus TRAIL may offer an effective therapeutic strategy for safely and selectively treating TRAIL-resistant bladder cancer cells.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.111-111
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• 2019

Glycyrrhizae radix is one of the most frequently prescribed ingredients in Oriental medicine, and G. radix extract has been shown to exert anti-cancer effects. However, the cellular and molecular mechanisms of apoptosis by G. radix are poorly defined. In the present study, it was examined the biochemical mechanisms of apoptosis by water extract of G. radix (WEGR) in human bladder T24 cancer cells. It was found that WEGR 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, DNA fragmentation and increased populations of annexin-V positive cells. The induction of apoptotic cell death by WEGR was connected with an up-regulation of pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL proteins, and inhibition of apoptosis family proteins (XIAP, cIAP-1 and cIAP-2). In addition, apoptosis-inducing concentrations of WEGR 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. WEGR also induced apoptosis via a death receptor-mediated extrinsic pathway by caspase-8 activation, resulting in the down-regulation of total Bid and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. Taken together, the present results suggest that WEGR may be a potential chemotherapeutic agent for the control of human bladder cancer cells.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.2019-2024
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• 2010

Insulin-like growth factor binding protein 5 (IGFBP-5) plays an important role in controlling cell survival, differentiation and apoptosis. Apoptosis can be induced by an extrinsic pathway involving the ligand-mediated activation of death receptors such as tumor necrosis factor receptor 1 (TNFR1). To determine whether IGFBP-5 and TNFR1 interact as members of the same apoptosis pathway, recombinant IGFBP-5 and TNFR1 were isolated. The expression and purification of the full-length TNFR1 and truncated IGFBP-5 proteins were successfully performed in E. coli. The binding of both IGFBP-5 and TNFR1 proteins was detected by surface plasmon resonance spectroscopy (BIAcore), fluorescence measurement, electron microscopy, and size-exclusion column (SEC) chromatography. IGFBP-5 indeed binds to TNFR1 with an apparent $K_D$ of 9 nM. After measuring the fluorescence emission spectra of purified IGFBP-5 and TNFR1, it was found that the tight interaction of these proteins is accompanied by significant conformational changes of one or both. These results indicate that IGFBP-5 acts potently as a novel ligand for TNFR1.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.20-27
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• 2014

Our study is investigated the effects of Nelumbo nucifera root extract on HT-29 colon cancer cells. The anti-proliferative effect of 70% ethanol extract from Nelumbo nucifera root on HT-29 colon cancer cells was identified based on cell viability, Hoechst 33342 nuclear staining, apoptosis analysis, Western blotting and RT-PCR analyses. In our study, Nelumbo nucifera root extract inhibited the growth of HT-29 colon cancer cells in a dose-dependent manner. Concomitant activation of the mitochondria-dependent apoptotic pathway of HT-29 colon cancer cells by Nelumbo nucifera root extract occurred via modulation of Bax and Bcl-2 expressions, which activated cleavage of caspases-3 and -9. The findings of this study indicate that Nelumbo nucifera root extract induces apoptosis in HT-29 colon cancer cells, and this phenomenon is occurs via the death receptor-mediated and mitochondria-mediated apoptotic pathways.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.3
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• pp.207-214
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• 2016

This study investigated the effects of ginger (Zingiber officinale Roscoe) on antioxidant and antiproliferative activities in A2058 human melanoma cells. The antioxidant and antiproliferative activities of 70% ethanol extracts of Zingiber officinale Roscoe were identified based on DPPH and ABTS free radical scavenging capacities. Treatment of cells with Zingiber officinale Roscoe at concentrations of 0, 0.2, and 0.4 mg/mL for 24 hours significantly reduced cell viability as determined by Hoechst 33258 nuclear staining, apoptosis analysis, and Western blotting analysis, respectively. In our study, 70% ethanol extracts of Zingiber officinale Roscoe exhibited antioxidant activity and inhibited A2058 cell growth in a dose-dependent manner. Concomitant activation of the mitochondria-dependent apoptotic pathway of A2058 human melanoma cells by Zingiber officinale Roscoe extracts was mediated via modulation of Bax and Bcl-2 expression, which activated cleavage of caspases-3, caspases-9, and poly ADP-ribose polymerase. The findings of study indicate that Zingiber officinale Roscoe extracts induce apoptosis in A2058 human melanoma cells, and this phenomenon occurs via the death receptor-mediated and intrinsic pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.3981-3986
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• 2014

Ganoderma lucidum polysaccharides (GLP) extracted from Ganoderma lucidum have been shown to induce cell death in some kinds of cancer cells. This study investigated the cytotoxic and apoptotic effect of GLP on HCT-116 human colon cancer cells and the molecular mechanisms involved. Cell proliferation, cell migration, lactate dehydrogenase (LDH) levels and intracellular free calcium levels ($[Ca^{2+}]i$) were determined by MTT, wound-healing, LDH release and fluorescence assays, respectively. Cell apoptosis was observed by scanning and transmission electron microscopy. For the mechanism studies, caspase-8 activation, and Fas and caspase-3 expression were evaluated. Treatment of HCT-116 cells with various concentrations of GLP (0.625-5 mg/mL) resulted in a significant decrease in cell viability (P< 0.01). This study showed that the antitumor activity of GLP was related to cell migration inhibition, cell morphology changes, intracellular $Ca^{2+}$ elevation and LDH release. Also, increase in the levels of caspase-8 activity was involved in GLP-induced apoptosis. Western blotting indicated that Fas and caspase-3 protein expression was up-regulated after exposure to GLP. This investigation demonstrated for the first time that GLP shows prominent anticancer activities against the HCT-116 human colon cancer cell line through triggering intracellular calcium release and the death receptor pathway.