High Sodium Intake, as Assessed by Urinary Sodium Excretion, Is Associated with Nonalcoholic Fatty Liver Disease or Sarcopenia

Background/Aims@#We explored whether high sodium intake, assessed by urinary excretion, determines the risk of sarcopenia and nonalcoholic fatty liver disease (NAFLD). @*Methods@#We analyzed 10,036 adult participants with normal kidney function from the Korea National Health and Nutrition Examination Survey (2008–2011). NAFLD was identified using the fatty liver index, and the muscle mass was evaluated using dual X-ray absorptiometry. The dietary sodium intake was estimated using Tanaka’s equation. @*Results@#The mean 24-hour urinary sodium excretion was 144.2±36.1 mmol/day (corresponding to 3.3 g/day Na) in the total population. The 24-hour urinary sodium excretion showed moderate accuracy in predicting NAFLD (area under the receiver operating characteristic, 0.702; 95% confidence interval [CI], 0.692 to 0.712). A cutoff value of 99.96 mmol/day (corresponding to 2.30 g/day Na) for urinary sodium excretion in predicting NAFLD showed 76.1% sensitivity and 56.1% specificity. The results of multiple adjusted models indicated that the participants with the highest urinary sodium excretion had a significantly higher risk of NAFLD (odds ratio, 1.46; 95% CI, 1.27 to 1.66; p<0.001) and sarcopenia (odds ratio, 1.49; 95% CI, 1.28 to 1.73; p<0.001) than those with the lowest urinary sodium excretion. The association between a higher 24-hour urinary sodium excretion and NAFLD was independent of sarcopenia. @*Conclusions@#Participants with a high sodium intake, as assessed by sodium excretion, had a substantial risk of NAFLD and sarcopenia

The Histone Lysine-specific Demethylase 1 Inhibitor, SP2509 Exerts Cytotoxic Effects against Renal Cancer Cells through Downregulation of Bcl-2 and Mcl-1

Lysine-specific histone demethylase 1 (LSD1), also known as KDM1A, can remove the methyl group from lysine 4 and 9 at histone H3, which regulates transcriptional suppression and activation. Recently, high expression of LSD1 in tumors has been shown to be involved in cancer cell proliferation, metastasis, and poor prognosis. We found that SP2509, a potent and reversible inhibitor of LSD1, induced apoptosis in human renal carcinoma (Caki and ACHN) and glioma (U87MG) cells. Pharmacological inhibition and siRNA-mediated silencing of LSD1 expression effectively downregulated anti-apoptotic proteins such as Bcl-2 and Mcl-1. Ectopic expression of these proteins markedly attenuated SP2509-induced apoptosis. At a mechanistic level, we found that inhibition of LSD1 downregulated Bcl-2 at a transcriptional level. Interestingly, protein expression of Mcl-1 was modulated at a post-translation level. Our results reveal that LSD1 could induce apoptotic cell death in renal carcinoma cells through downregulation of Bcl-2 and Mcl-1.

Involvement of Up-regulation of Death Receptors and Bim in Hispolon-mediated TNF-related Apoptosis-inducing Ligand Sensitization in Human Renal Carcinoma

BACKGROUND: Hispolon has been shown to possess antitumor effects in various cancer cells. However, the underlying mechanisms are not fully understood. In this study, we evaluated the sensitizing effect of hispolon on TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in human renal carcinoma cells. METHODS: Apoptosis was analyzed by using cell-based cytometer. The mRNA levels were assessed by reverse transcription-PCR. Bax activation was determined by oligomerization and fluorescence-activated cell sorting with Bax-NT monoclonal antibody. The protein expression was measured by Western blotting. RESULTS: Hispolon induced up-regulation of Bim and death receptors expression at the post-translational level. CONCLUSIONS: Hispolon enhanced TRAIL-mediated apoptosis in renal carcinoma cells, but not in normal cells.

Novel non-apoptotic cell death: ferroptosis / 영남의대학술지

Ferroptosis is a newly recognized type of cell death that results from iron-dependent lipid peroxidation and is different from other types of cell death, such as apoptosis, necrosis, and autophagic cell death. This type of cell death is characterized by mitochondrial shrinkage with an increased mitochondrial membrane density and outer mitochondrial membrane rupture. Ferroptosis can be induced by a loss of activity of system Xc− and the inhibition of glutathione peroxidase 4, followed by the accumulation of lipid reactive oxygen species (ROS). In addition, inactivation of the mevalonate and transsulfuration pathways is involved in the induction of ferroptosis. Moreover, nicotinamide adenine dinucleotide phosphate oxidase and p53 promote ferroptosis by increasing ROS production, while heat shock protein beta-1 and nuclear factor erythroid 2-related factor 2 inhibit ferroptosis by reducing iron uptake. This article outlines the molecular mechanisms and signaling pathways of ferroptosis regulation, and explains the roles of ferroptosis in human disease.

Novel non-apoptotic cell death: ferroptosis / 영남의대학술지

Ferroptosis is a newly recognized type of cell death that results from iron-dependent lipid peroxidation and is different from other types of cell death, such as apoptosis, necrosis, and autophagic cell death. This type of cell death is characterized by mitochondrial shrinkage with an increased mitochondrial membrane density and outer mitochondrial membrane rupture. Ferroptosis can be induced by a loss of activity of system Xc− and the inhibition of glutathione peroxidase 4, followed by the accumulation of lipid reactive oxygen species (ROS). In addition, inactivation of the mevalonate and transsulfuration pathways is involved in the induction of ferroptosis. Moreover, nicotinamide adenine dinucleotide phosphate oxidase and p53 promote ferroptosis by increasing ROS production, while heat shock protein beta-1 and nuclear factor erythroid 2-related factor 2 inhibit ferroptosis by reducing iron uptake. This article outlines the molecular mechanisms and signaling pathways of ferroptosis regulation, and explains the roles of ferroptosis in human disease.

Dexamethasone Inhibits Interleukin-1beta-Induced Matrix Metalloproteinase-9 Expression in Cochlear Cells

OBJECTIVES: To investigate the effect of interleukin (IL)-1beta on matrix metalloproteinase (MMP)-9 expression in cochlea and regulation of IL-1beta-mediated MMP-9 expression by dexamethasone and the molecular and signaling mechanisms involved. METHODS: House ear institute-organ of Corti 1 (HEI-OC1) cells were used and exposed to IL-1beta with/without dexamethasone. Glucocorticoid receptor antagonist, RU486, was used to see the role of dexamethasone. PD98059 (an extracellular signal-regulated kinases [ERKs] inhibitor), SB203580 (a p38 mitogen-activated protein kinases [MAPK] inhibitor), SP600125 (a c-Jun N-terminal kinase [JNK] inhibitor) were also used to see the role of MAPKs signaling pathway(s) in IL-1beta-induced MMP-9 expression in HEI-OC1 cells. Reverse transcription-polymerase chain reaction and gelatin zymography were used to measure mRNA expression level of MMP-9 and activity of MMP-9, respectively. RESULTS: Treatment with IL-1beta-induced the expression of MMP-9 in a dose- and time-dependent manner. IL-1beta (1 ng/mL)-induced MMP-9 expression was inhibited by dexamethasone. Interestingly, p38 MAPK inhibitor, SB203580, significantly inhibited IL-1beta-induced MMP-9 mRNA and MMP-9 activity. However, inhibition of JNKs and ERKs had no effect on the IL-1beta-induced MMP-9 expression. CONCLUSION: These results suggest that the pro-inflammatory cytokine IL-1beta strongly induces MMP-9 expression via activation of p38 MAPK signaling pathway in HEI-OC1 cells and the induction was inhibited by dexamethasone.

The colchicine derivative CT20126 shows a novel microtubule-modulating activity with apoptosis

New colchicine analogs have been synthesized with the aim of developing stronger potential anticancer activities. Among the analogs, CT20126 has been previously reported to show immunosuppressive activities. Here, we report that CT20126 also shows potential anticancer effects via an unusual mechanism: the modulation of microtubule integrity and cell cycle arrest at the G2/M phase before apoptosis. When we treated COS-7 cells with CT20126 (5 muM), the normal thread-like microtubules were disrupted into tubulin dimers within 10 min and thereafter repolymerized into short, thick filaments. In contrast, cells treated with the same concentration of colchicine exhibited microtubule depolymerization after 20 min and never underwent repolymerization. Furthermore, optical density (OD) analysis (350 nm) with purified tubulin showed that CT20126 had a higher repolymerizing activity than that of Taxol, a potent microtubule-polymerizing agent. These results suggest that the effects of CT20126 on microtubule integrity differ from those of colchicine: the analog first destabilizes microtubules and then stabilizes the disrupted tubulins into short, thick polymers. Furthermore, CT20126 induced a greater level of apoptotic activity in Jurkat T cells than colchicine (assessed by G2/M arrest, caspase-3 activation and cell sorting). At 20 nM, CT20126 induced 47% apoptosis among Jurkat T cells, whereas colchicine induced only 33% apoptosis. Our results suggest that the colchicine analog CT20126 can potently induce apoptosis by disrupting microtubule integrity in a manner that differs from that of colchicine or Taxol.

Paxilline enhances TRAIL-mediated apoptosis of glioma cells via modulation of c-FLIP, survivin and DR5

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) induces apoptosis selectively in cancer cells while sparing normal cells. However, many cancer cells are resistant to TRAIL-induced cell death. Here, we report that paxilline, an indole alkaloid from Penicillium paxilli, can sensitize various glioma cells to TRAIL-mediated apoptosis. While treatment with TRAIL alone caused partial processing of caspase-3 to its p20 intermediate in TRAIL-resistant glioma cell lines, co-treatment with TRAIL and subtoxic doses of paxilline caused complete processing of caspase-3 into its active subunits. Paxilline treatment markedly upregulated DR5, a receptor of TRAIL, through a CHOP/GADD153-mediated process. In addition, paxilline treatment markedly downregulated the protein levels of the short form of the cellular FLICE-inhibitory protein (c-FLIPS) and the caspase inhibitor, survivin, through proteasome-mediated degradation. Taken together, these results show that paxilline effectively sensitizes glioma cells to TRAIL-mediated apoptosis by modulating multiple components of the death receptor-mediated apoptotic pathway. Interestingly, paxilline/TRAIL co-treatment did not induce apoptosis in normal astrocytes, nor did it affect the protein levels of CHOP, DR5 or survivin in these cells. Thus, combined treatment regimens involving paxilline and TRAIL may offer an attractive strategy for safely treating resistant gliomas.

Rottlerin enhances IL-1beta-induced COX-2 expression through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells

Cyclooxygenase-2 (COX-2) is an important enzyme in inflammation. In this study, we investigated the underlying molecular mechanism of the synergistic effect of rottlerin on interleukin1beta (IL-1beta)-induced COX-2 expression in MDA-MB-231 human breast cancer cell line. Treatment with rottlerin enhanced IL-1beta-induced COX-2 expression at both the protein and mRNA levels. Combined treatment with rottlerin and IL-1beta significantly induced COX-2 expression, at least in part, through the enhancement of COX-2 mRNA stability. In addition, rottlerin and IL-1beta treatment drove sustained activation of p38 Mitogen-activated protein kinase (MAPK), which is involved in induced COX-2 expression. Also, a pharmacological inhibitor of p38 MAPK (SB 203580) and transient transfection with inactive p38 MAPK inhibited rottlerin and IL-1beta-induced COX-2 upregulation. However, suppression of protein kinase C delta (PKC delta) expression by siRNA or overexpression of dominant-negative PKC delta (DN-PKC-delta) did not abrogate the rottlerin plus IL-1beta-induced COX-2 expression. Furthermore, rottlerin also enhanced tumor necrosis factor-alpha (TNF-alpha), phorbol myristate acetate (PMA), and lipopolysaccharide (LPS)-induced COX-2 expression. Taken together, our results suggest that rottlerin causes IL-1beta-induced COX-2 upregulation through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells.

Apoptosis and upregulation of TNF-alpha and TRAIL receptor 1 (DR4) in the pathogenesis of food protein-induced enterocolitis syndrome / 소아과

PURPOSE: Expression levels of tumor necrosis factor (TNF)-alpha expression on the mucosa of the small intestine is increased in patients with villous atrophy in food protein-induced enterocolitis syndrome (FPIES). TNF-alpha has been reported to induce apoptotic cell death in the epithelial cells. We studied the TNF family and TNF-receptor family apoptosis on the duodenal mucosa to investigate their roles in the pathogenesis of FPIES. METHODS: Fifteen infants diagnosed as having FPIES using standard oral challenge test and 5 controls were included. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining was performed to identify the apoptotic cell death bodies. Immunohistochemical staining of TNF-alpha, Fas ligand (FasL) for TNF family and TNF-related apoptosis-including ligand (TRAIL) receptor 1 (DR4), TRAIL receptor 2 (DR5), and Fas for TNF-receptor family were performed to determine the apoptotic mechanisms. RESULTS: TUNEL+ was significantly more highly expressed in the duodenal mucosa of FPIES patients than in controls (P=0.043). TNF-alpha (P=0.0001) and DR4 (P=0.003) were significantly more highly expressed in FPIES patients than in controls. Expression levels of FasL, Fas, and DR5 were low in both groups and were not significantly different between the 2 groups. CONCLUSION: These results suggest that FPIES pathogenesis is induced by apoptosis, and that TNF-alpha expression and DR4 pathway may have an important role in apoptosis.

Interleukin-1beta promotes the expression of monocyte chemoattractant protein-1 in human aorta smooth muscle cells via multiple signaling pathways

Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1beta-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-kappaB inhibitor completely suppressed the IL-1beta-induced MCP1 expression through blocking NF-kappaB translocation to the nucleus. Pretreatment with inhibitors of tyrosine kinase or PLD partially suppressed MCP1 expression and failed to block nuclear NF-kappaB translocation. These results suggest that IL-1beta induces MCP1 expression through activation of NF-kappaB via the PC-PLC/PKC signaling pathway.

alpha-Lipoic acid inhibits matrix metalloproteinase-9 expression by inhibiting NF-kappaB transcriptional activity

The migration of vascular smooth muscle cells (VSMCs) into the intima, an important step in injury-induced neointimal hyperplasia, requires the activation of nuclear factor-kappaB (NF-kappaB) and the consequent up-regulation of matrix metalloproteinase-9 (MMP-9). This study was undertaken to test for a possible effect of alpha-lipoic acid (ALA), a potent inhibitor of NF-kappaB, on MMP-9 expression. ALA inhibited high-glucose- and TNF-alpha-stimulated VSMC migrations in vitro. It also inhibited high-glucose- and TNF-alpha-induced increases in MMP-9 expression. The activity of MMP-9-promoter constructs with mutations in the NF-kappaB binding site was not inhibited by ALA, indicating an involvement of the NF-kappaB signaling pathway in the ALA-specific inhibition of MMP-9. These data suggest the possibility that ALA may be useful for the prevention of neointimal hyperplasia after angioplasty, by inhibiting the NF-kappaB/ MMP-9 pathway, especially with hyperglycemia.

zVAD-fmk, unlike BocD-fmk, does not inhibit caspase-6 acting on 14-3-3/Bad pathway in apoptosis of p815 mastocytoma cells

In a preliminary study, we found that benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD- fmk), unlike Boc-aspartyl(OMe)-fluoromethylketone (BocD-fmk), at usual dosage could not prevent genistein-induced apoptosis of p815 mastocytoma cells. This study was undertaken to reveal the mechanism underlying the incapability of zVAD-fmk in preventing this type of apoptosis. We observed that 14-3-3 protein level was reduced in genistein-treated cells and that BocD-fmk but not zVAD-fmk prevented the reduction of 14-3-3 protein level and the release of Bad from 14-3-3. We also demonstrated that truncated Bad to Bcl-xL interaction in genistein- treated cells was prevented by BocD-fmk but not by zVAD-fmk treatment. Our data indicate that BocD- fmk, compared to zVAD-fmk, has a certain preference for inhibiting 14-3-3/Bad signalling pathway. We also elucidated that this differential efficacy of BocD-fmk and zVAD-fmk resulted from the different effect in inhibiting caspase-6 and that co-treatment of zVAD-fmk and caspase-6 specific inhibitor substantially prevented genistein-induced apoptosis. Our data shows that caspase-6 plays a role on Bad/14-3-3 pathway in genistein-induced apoptosis of p815 cells, and that the usual dose of zVAD-fmk, in contrast to BocD-fmk, did not prevent caspase-6 acting on 14-3-3/Bad-mediated event.

A Combination of PG490 and Lipopolysaccharide Induce Apoptosis through Activation of Casapase-3 and Down- regulation of cIAP1 and XIAP in Human Astroglioma Cell

BACKGROUND: Malignant gliomas are the most common primary tumors in the central nervous system. METHODS: We investigated the combined effect of PG490 and LPS on the induction of the apoptotic pathway in human astroglioma cells. RESULTS: Treatment of U87 cells with combination of 50 nM of PG490 and 50microgram/ml of LPS resulted in increased internucleosomal DNA fragmentation, cleavage of PLC-gamma1, and down- regulation of cIAP1 and XIAP. The combination of LPS and PG490 treatment-induced apoptosis is mediated through the activation of caspase, which is inhibited by the caspase inhibitor, z-VAD-fmk. Also, release of cytochrome c was found in PG490 and LPS- cotreated U87 cell. CONCLUSION: Taken together, combination of PG490 and LPS appears to be a potent inducer of apoptosis in astrogliaoma cells, and might have some benefit in the treatment of glioma patients.

The Study about Expression and Regulation Mechanism of Heat Shock Protein 70 by Arisostatins A in Caki Cell Line of Renal Cell Carcinoma / 대한비뇨기과학회지

PURPOSE: The events of cell stress and cell death are linked, with the heat shock proteins (Hsps) induced in response to stress appearing to function at key regulatory points in the control of apoptosis. The purpose of this study was to investigate the effect of arisostatins A on the Hsp70 expression and signal mechanism of its transcription. MATERIALS AND METHODS: We used natural arisostatins A produced by Actinomycete, in Caki cells. We measured the growth rate of cell using trypan blue staining, and the induction of the transcriptional levels of Hsp70 with arisostatins, which was quantified by reverse transcript-polymerase chain reaction (RT-PCR) and transiently transfecting cells with a Hsp70. The induction of the transcriptional levels of Hsp70 with arisostatins A was quantified by RT-PCR and transiently transfecting cells with a Hsp70 promoter-luciferase reporter plasmid. RESULTS: Arisostatins A-induced Hsp70 up-regulation was not prevented by the overexpression of peroxiredoxinI (PrxI), PrxII or treatment of superoxide dismutase and catalase. However, the arisostatins A-mediated expression of Hsp70 was reduced significantly in Caki cells treated by the antioxidant, N-acetylcystein. Inhibition of the Janus tyrosine kinase (JAK) activity with AG490 did not inhibit the arisostatins A-induced Hsp70 up-regulation, suggesting that JAK is not associated with the arisostatins A-mediated Hsp70 expression. The mechanism of Hsp70 induction depends on the activation of heat shock factor-1. However, arisostatins A did not effect the change in the expression levels of heat shock factor-1. CONCLUSIONS: These findings suggested that Hsp directly regulates specific stress-responsive signaling pathways, which may antagonize the signaling cascades that result in apoptosis.

Expression of Human beta-defensin 2 mRNA by Lipopolysaccharide in Human Corneal Epithelial Cells

Recently the transcriptional up-regulation of human beta-defensin 2 (HBD-2) by lipopolysaccharide (LPS) was found to be associated with NF-kappaB binding site. Although the general mechanisms of NF-kappaB activation by LPS stimulation are well understood, less is known about the signal transduction pathway leading to LPS-induced NF-kappaB activation in human corneal epithelial (HCE) cells. The aim of this study was to investigate the intracellular signals involved in LPS-induced HBD-2 mRNA expression in HCE cells. Pretreatments of inhibitors for NF-kappaB, protein tyrosine kinase, p38 mitogen activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) attenuated the LPS-induced NF-kappaB DNA binding activity and HBD-2 mRNA expression. Furthermore, pretreatments with inhibitors for protein kinase C (PKC), phosphatidylcholine-phospholipase C, phosphatidylinositol-phospholipase C, or phosphatidate phosphohydrolase prevented LPS-induced HBD-2 mRNA expression and HBD-2 prmoter-driven luciferase activity. However, the increased expression of HBD-2 mRNA and the increased DNA binding activity of NF-kappaB induced by LPS were not changed by the blockage of extracellular signal-regulated kinase (ERK) and of addition of antioxidants. Forskolin, a protein kinase A (PKA) agonist did not induce HBD-2 mRNA expression. These data demonstrate that LPS-induced HBD-2 mRNA expression via NF-kappaB is, at least in part, dependent on PKC, p38 MAPK, JNK, and protein tyrosine kinase status, but appears to be independent on PKA, ERK and ROS in HCE cells. Taken together, there may be more than one signaling pathways that lead to LPS-induced up-regulation of HBD-2 mRNA expression in HCE cells.

Expression of IAP Genes During TPA-Induced Differentiation of HL-60 Cells

HL-60 cells (human promyelocytic leukemia cells) differentiate into the monocyte/macrophage like cells that die spontaneously by apoptosis when treated with 12-O-tetradecanoylphorbol-13-acetate (TPA). It is known that inhibitors of apoptosis proteins (IAP) bind to and inhibit caspase 3, 7, 9 activity and the induction of apoptosis. In this study, we examined the expression of IAP genes during TPA induced differentiation of HL-60 cells. During the differentiation, HIAP-1, HIAP-2, and XIAP expressions were decreased in protein levels. The pan-caspase inhibitor z-VAD-fmk blocked the decrease of HIAP-1 and HIAP-2, which indicates HIAP-1 and HIAP-2 could be caspase substrates. These findings suggest that the decrease of IAP proteins is related to the induction of apoptosis that is associated with TPA- induced HL-60 cell differentiation.

Expressional Regulation of Cancer Metastasis Related Gene, MMP-9, by Resveratrol

Proteolytic degradation of the extracellular matrix and tumor metastasis correlate with the expression of endopeptidases known as matrix metalloproteinases (MMPs). Expression of MMPs is regulated by cytokines and signal transduction pathways including those activated by phorbol myristate acetate (PMA). We found that resveratrol, a phytoalexin present in grapes, significantly inhibits the PMA-induced increase of MMP-9 expression and activity. These effects of resveratrol were dose-dependent and correlated with the suppression of MMP-9 mRNA expression levels. PMA caused a 23-fold increase in MMP-9 promoter activity, which was suppressed by resveratrol. Transient transfection by MMP-9 constructs, in which specific transcriptional factors were mutagenized, indicated that the effects of PMA and resveratrol were mediated via AP1 and NFkB response elements. Resveratrol inhibited PMA-mediated activation of c-Jun Nterminal kinase (JNK) and protein kinase C (PKC)-delta activation. Therefore, we conclude that the inhibitory activities of resveratrol on MMP-9, JNK, and PKC-delta may have therapeutic potential for controlling growth and invasiveness of tumors.

Effect of curcumin and resveratrol on the cell cycle regulation, apoptosis and inhibition of metastasis related proteins in HN-4 cells

Nontraditional or alternative medicine is becoming an increasingly attractive approach for the treatment of various inflammatory disorders and cancers. Curcumin is the major constitute of turmoric powder extracted from the rhizomes of the plant Curcuma longa. Resveratrol is a phytoalexin present in grapes and a variety of medicinal plants. In this report, We investigated the effect of curcumin and resveratrol on regulatory protein of cell cycle, induction of apoptosis and MMP activity. Treatment with 75 M curcumin for 24 hrs produced morphological changing in HN-4 cells. Curcumin and resveratrol inhibited the cellular growth in HN-4 cells. Inhibition of cell growth was associated with down-regulation of cell cycle regulatory proteins. Curcumin-induced caspase-3 activation and Bax degradation were dose-dependent with a maximal effect at a concentration of 100 M. The elevated caspase-3 activity in curcumin treated HN-4 cells are correlated with down-regulation of survivin and cIAP1, but not cIAP2. Curcumin induced a dose-dependent increase of cytochrome c in the cytosol. Curcumin induced-apoptosis was mediated through the release of cytochrome c. In addition, curcumin-induced apoptosis was caused by the generation of reactive oxygen species, which was prevented by antioxidant N-acetyl-cysteine (NAC). Cotreatment with NAC markedly prevented cytochrome c release, Bax cleavage and cell death. Also resveratrol-induced apoptosis was preceded by down-regulation of the anti-apoptotic Bcl-2, cIAP1, and caspase-3 activity. However, resveratrol-induced apoptosis was not prevented by antioxidant NAC. In addition, HN-4 cells release basal levels of MMP2 when cultured in serum-free medium. Treatment of the cells with various concentrations of PMA for 24 hr induced the expression and secretion of latent MMP9 as determined by gelatin zymography. HN-4 cells were treated with various concentrations of curcumin and resveratrol in the presence of 75 nM PMA, and MMP2 and 9 activities were inhibited by curcumin and resveratrol. These findings have implications for developing curcumin-based anticancer and anti-inflammation therapies.

Curcumin Induces Apoptosis and Inhibits Metalloproteinase Activity in Renal Cancer Cell Line / 대한비뇨기과학회지

PURPOSE: Curcumin is the major constitute of turmeric powder extracted from the rhizomes of the plant Curcuma longa. We investigated that the effect of curcumin on regulatory protein of cell cycle, induction of apoptosis and metalloproteinase (MMP) activity in Caki cells, renal cell carcinoma (RCC) line. MATERIALS AND METHODS: The Caki cells were treated with curcumin for 24 h and cells were visually monitored and photographed. The cell viability was determined by trypan blue exclusion staining. The expression levels of cell cycle regulatory proteins and apoptosis regulatory proteins were determined by Western blot. To address the significance of caspase activation in curcumin-induced apoptosis, we used a general and potent inhibitor of caspases, z-VAD-fmk. The expression and secretion of MMP were determined by gelatin zymography. RESULTS: Treatment with curcumin produced morphological changing and DNA fragmentation in Caki cells. It also inhibited cellular growth and reduced cell viability in Caki cells. Inhibition of cell growth was associated with down-regulation of cell cycle regulatory proteins. Reduction of cell viability was associated with caspase 3 activation. The elevated caspase 3 activity in curcumin treated Caki cells are correlated with down-regulation of XIAP and cIAP1. Caspase inhibitor co-treated cells abolished curcumin-induced caspase 3 activity. The release of cytochrome c in curcumin-induced Caki cells was dose-dependent manners. Although MMP-2 expression levels were not significantly altered, however, the expression and secretion levels of MMP-9 were induced by PMA dose-dependent manners. CONCLUSIONS: Curcumin induces apoptosis and inhibit invasion by down regulation of regulatory protein of cell cycle, apoptosis related protein and MMP activity. These findings have implications for developing curcumin-based anticancer prevention or therapy of RCC.