scholarly journals Diosgenin Induces Apoptosis in HepG2 Cells through Generation of Reactive Oxygen Species and Mitochondrial Pathway

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Dae Sung Kim ◽  
Byoung Kook Jeon ◽  
Young Eun Lee ◽  
Won Hong Woo ◽  
Yeun Ja Mun
Keyword(s):  
P38 Mapk ◽  
Hepg2 Cells ◽  
Caspase 3 ◽  
Mitochondrial Pathway ◽  
Carcinoma Cells ◽  
Dapi Staining ◽  
Apoptotic Pathway ◽  
Induced Apoptosis ◽  
Dose Dependent ◽  
Human Hepatocellular Carcinoma Cells

Diosgenin, a naturally occurring steroid saponin found abundantly in legumes and yams, is a precursor of various synthetic steroidal drugs. Diosgenin is studied for the mechanism of its action in apoptotic pathway in human hepatocellular carcinoma cells. Based on DAPI staining, diosgenin-treated cells manifested nuclear shrinkage, condensation, and fragmentation. Treatment of HepG2 cells with 40 μM diosgenin resulted in activation of the caspase-3, -8, -9 and cleavage of poly-ADP-ribose polymerase (PARP) and the release of cytochromec.In the upstream, diosgenin increased the expression of Bax, decreased the expression of Bid and Bcl-2, and augmented the Bax/Bcl-2 ratio. Diosgenin-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of JNK, p38 MAPK and apoptosis signal-regulating kinase (ASK)-1, as well as generation of the ROS. NAC administration, a scavenger of ROS, reversed diosgene-induced cell death. These results suggest that diosgenin-induced apoptosis in HepG2 cells through Bcl-2 protein family-mediated mitochndria/caspase-3-dependent pathway. Also, diosgenin strongly generated ROS and this oxidative stress might induce apoptosis through activation of ASK1, which are critical upstream signals for JNK/p38 MAPK activation in HepG2 cancer cells.

Synergistic Effect of α-Solanine and Cisplatin Induces Apoptosis and Enhances Cell Cycle Arrest in Human Hepatocellular Carcinoma Cells

2020 ◽  
Vol 19 (18) ◽  
pp. 2197-2210 ◽  
Author(s):  
Sherien M. El-Daly ◽  
Shaimaa A. Gouhar ◽  
Amira M. Gamal-Eldeen ◽  
Fatma F. Abdel Hamid ◽  
Magdi N. Ashour ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Synergistic Effect ◽  
Cell Cycle Arrest ◽  
Combination Treatment ◽  
Carcinoma Cells ◽  
Cell Growth Inhibition ◽  
Cycle Arrest ◽  
Induced Apoptosis ◽  
Human Hepatocellular Carcinoma Cells

Aim: The clinical application of cisplatin is limited by severe side effects associated with high applied doses. The synergistic effect of a combination treatment of a low dose of cisplatin with the natural alkaloid α-solanine on human hepatocellular carcinoma cells was evaluated. Methods: HepG2 cells were exposed to low doses of α-solanine and cisplatin, either independently or in combination. The efficiency of this treatment modality was evaluated by investigating cell growth inhibition, cell cycle arrest, and apoptosis enhancement. Results: α-solanine synergistically potentiated the effect of cisplatin on cell growth inhibition and significantly induced apoptosis. This synergistic effect was mediated by inducing cell cycle arrest at the G2/M phase, enhancing DNA fragmentation and increasing apoptosis through the activation of caspase 3/7 and/or elevating the expression of the death receptors DR4 and DR5. The induced apoptosis from this combination treatment was also mediated by reducing the expression of the anti-apoptotic mediators Bcl-2 and survivin, as well as by modulating the miR-21 expression. Conclusion: Our study provides strong evidence that a combination treatment of low doses of α-solanine and cisplatin exerts a synergistic anticancer effect and provides an effective treatment strategy against hepatocellular carcinoma.

Urea sensitizes mIMCD3 cells to heat shock-induced apoptosis: protection by NaCl

2001 ◽  
Vol 280 (3) ◽  
pp. C614-C620 ◽  
Author(s):  
Chantal Colmont ◽  
Stéphanie Michelet ◽  
Dominique Guivarc'h ◽  
Germain Rousselet
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Heat Sensitivity ◽  
Osmotic Gradient ◽  
Water Reabsorption ◽  
Apoptotic Pathway ◽  
Shock Response ◽  
Induced Apoptosis ◽  
Shock Proteins ◽  
Dose Dependent

Urea, with NaCl, constitutes the osmotic gradient that allows water reabsorption in mammalian kidneys. Because NaCl induces heat shock proteins, we tested the responses to heat shock of mIMCD3 cells adapted to permissive urea and/or NaCl concentrations. We found that heat-induced cell death was stronger after adaptation to 250 mM urea. This effect was reversible, dose dependent, and, interestingly, blunted by 125 mM NaCl. Moreover, we have shown that urea-adapted cells engaged in an apoptotic pathway upon heat shock, as shown by DNA laddering. This sensitization is not linked to a defect in the heat shock response, because the induction of HSP70 was similar in isotonic and urea-adapted cells. Moreover, it is not linked to the presence of urea inside cells, because washing urea away did not restore heat resistance and because applying urea and heat shock at the same time did not lead to heat sensitivity. Together, these results suggest that urea modifies the heat shock response, leading to facilitated apoptosis.

scholarly journals Adriamycin activity's durational governance of different cell death types and zonality in rat liver acinus. Immunohistochemical studies

2014 ◽  
Vol 58 (1) ◽  
pp. 125-133
Author(s):  
Agnieszka Pedrycz ◽  
Zbigniew Boratyński ◽  
Piotr Siermontowski ◽  
Jacek Mendocha ◽  
Marcin Orłowski ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Mitochondrial Pathway ◽  
Immunohistochemical Method ◽  
Extrinsic Pathway ◽  
Apoptotic Pathway ◽  
Liver Acinus ◽  
Group I ◽  
Female Wistar Rats ◽  
Immunohistochemical Studies

Abstract The aim of this study was to develop and examine a model of apoptosis and necrosis of hepatocytes induced by a damaging factor - adriamycin, correlating time after its administration with cell death type, and to investigate the localisation within the liver acinus of hepatocytes dying in these two ways. The results obtained in the present and previous studies were compared in order to make a map of cell death localisation in the liver acinus, showing the effect of time in action and dose of adriamycin. The experiment was performed on 32 female Wistar rats, divided into four groups: I and II - experimental, and III and IV - control. Adriamycin (3 mg/kg b.w.) was administered intraperitoneally to rats in groups I and II, and the rats were decapitated after four (group I) and eight (group II) weeks. Animals in control groups III and IV were given 0.5 mL of 0.9% NaCl solution, and decapitated after four and eight weeks respectively. Sections of the liver were examined with a three-stage immunohistochemical method. This method allowed to examine hepatocytes qualitatively and quantitatively for the presence of proteins involved in three types of apoptosis: induced by the mitochondrial pathway (caspase 3, 9), the intrinsic pathway related to endoplasmic reticulum stress (caspase 3, 12), and the extrinsic pathway (caspase 3, 8). One of the inflammatory markers, caspase 1, was also examined. The zonal localisation of all three types of apoptosis was assessed in the liver tissue. More oxidated hepatocytes indicated only signs of the internal mitochondrial pathway, whereas less oxidated hepatocytes induced the internal reticular pathway and the external apoptotic pathway. The period between adriamycin administration and hepatic cell investigation was a main factor of the process. A longer period post insult resulted in a more pronounced effect of the activation of apoptosis. Sections explored eight weeks after treatment with different doses of the drug (3 and 5 mg/kg in the previous study) showed a similar intensity of apoptosis.

Identification of apoptotic genes mediating TGF-β/Smad3-induced cell death in intestinal epithelial cells using a genomic approach

2007 ◽  
Vol 292 (1) ◽  
pp. G28-G38 ◽  
Author(s):  
Yanna Cao ◽  
Lu Chen ◽  
Weili Zhang ◽  
Yan Liu ◽  
Harry T. Papaconstantinou ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Intestinal Epithelial ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Genomic Approach ◽  
Apoptotic Genes ◽  
Induced Apoptosis

Transforming growth factor (TGF)-β-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Previously, we have shown that TGF-β inhibits the growth of rat intestinal epithelial (RIE)-1 cells. However, RIE-1 cells are relatively resistant to TGF-β-induced apoptosis due to a low endogenous Smad3-to-Akt ratio. Overexpression of Smad3 sensitizes RIE-1 cells (RIE-1/Smad3) to TGF-β-induced apoptosis by altering the Smad3-to-Akt ratio in favor of apoptosis. In this study, we utilized a genomic approach to identify potential downstream target genes that are regulated by TGF-β/Smad3. Total RNA samples were analyzed using Affymetrix oligonucleotide microarrays. We found that TGF-β regulated 518 probe sets corresponding to its target genes. Interestingly, among the known apoptotic genes included in the microarray analyses, only caspase-3 was induced, which was confirmed by real-time RT-PCR. Furthermore, TGF-β activated caspase-3 through protein cleavage. Upstream of caspase-3, TGF-β induced mitochondrial depolarization, cytochrome c release, and cleavage of caspase-9, which suggests that the intrinsic apoptotic pathway mediates TGF-β-induced apoptosis in RIE-1/Smad3 cells.

scholarly journals Elevated pressure enhanced TRAIL-induced apoptosis in hepatocellular carcinoma cells via ERK1/2-inactivation

2015 ◽  
Vol 20 (4) ◽  
Author(s):  
Eunyoung Hong ◽  
Eunil Lee ◽  
Joonhee Kim ◽  
Daeho Kwon ◽  
Yongchul Lim
Keyword(s):  
Specific Inhibitor ◽  
Underlying Mechanism ◽  
Elevated Pressure ◽  
Mitochondrial Pathway ◽  
Carcinoma Cells ◽  
Intrinsic Resistance ◽  
Hep3b Cells ◽  
Induced Apoptosis

AbstractThe high frequency of intrinsic resistance to TNF-related apoptosisinducing ligand (TRAIL) in tumor cell lines has necessitated the development of strategies to sensitize tumors to TRAIL-induced apoptosis. We previously showed that elevated pressure applied as a mechanical stressor enhanced TRAIL-mediated apoptosis in human lung carcinoma cells in vitro and in vivo. This study focused on the effect of elevated pressure on the sensitization of TRAIL-resistant cells and the underlying mechanism. We observed elevated pressure-induced sensitization to TRAIL-mediated apoptosis in Hep3B cells, accompanied by the activation of several caspases and the mitochondrial signaling pathway. Interestingly, the enhanced apoptosis induced by elevated pressure was correlated with suppression of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) phosphorylation and CREB without any change to other MAPKs. Phosphorylation of Bcl-2-associated death promoter (BAD) also decreased, leading to inhibition of the mitochondrial pathway. To confirm whether the activation of pERK1/2 plays a key role in the TRAIL-sensitizing effect of elevated pressure, Hep3B cells were pre-treated with the ERK1/2-specific inhibitor PD98059 instead of elevated pressure. Co-treatment with PD98059 and TRAIL augmented TRAIL-induced apoptosis and decreased BAD phosphorylation. The inhibition of ERK1/2 activation by elevated pressure and PD98059 also reduced BH3 interacting-domain death agonist (BID), thereby amplifying apoptotic stress at the mitochondrial level. Our results suggest that elevated pressure enhances TRAIL-induced apoptosis of Hep3B cells via specific suppression of ERK1/2 activation among MAPKs.

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