scholarly journals Reactive Oxygen Species-Mediated Autophagy by Ursolic Acid Inhibits Growth and Metastasis of Esophageal Cancer Cells

2020 ◽  
Vol 21 (24) ◽  
pp. 9409
Author(s):  
Na-Ri Lee ◽  
Ruo Yu Meng ◽  
So-Young Rah ◽  
Hua Jin ◽  
Navin Ray ◽  
...  

Ursolic acid (UA) possesses various pharmacological activities, such as antitumorigenic and anti-inflammatory effects. In the present study, we investigated the mechanisms underlying the effects of UA against esophageal squamous cell carcinoma (ESCC) (TE-8 cells and TE-12 cells). The cell viability assay showed that UA decreased the viability of ESCC in a dose-dependent manner. In the soft agar colony formation assay, the colony numbers and size were reduced in a dose-dependent manner after UA treatment. UA caused the accumulation of vacuoles and LC3 puncta, a marker of autophagosome, in a dose-dependent manner. Autophagy induction was confirmed by measuring the expression levels of LC3 and p62 protein in ESCC cells. UA increased LC3-II protein levels and decreased p62 levels in ESCC cells. When autophagy was hampered using 3-methyladenine (3-MA), the effect of UA on cell viability was reversed. UA also significantly inhibited protein kinase B (Akt) activation and increased p-Akt expression in a dose-dependent manner in ESCC cells. Accumulated LC3 puncta by UA was reversed after wortmannin treatment. LC3-II protein levels were also decreased after treatment with Akt inhibitor and wortmannin. Moreover, UA treatment increased cellular reactive oxygen species (ROS) levels in ESCC in a time- and dose-dependent manner. Diphenyleneiodonium (an ROS production inhibitor) blocked the ROS and UA induced accumulation of LC3-II levels in ESCC cells, suggesting that UA-induced cell death and autophagy are mediated by ROS. Therefore, our data indicate that UA inhibits the growth of ESCC cells by inducing ROS-dependent autophagy.

Author(s):  
Li Hu ◽  
Li-Li Li ◽  
Zhi-Guo Lin ◽  
Zhi-Chao Jiang ◽  
Hong-Xing Li ◽  
...  

The potassium (K+) channel plays an important role in the cell cycle and proliferation of tumor cells, while its role in brain glioma cells and the signaling pathways remains unclear. We used tetraethylammonium (TEA), a nonselective antagonist of big conductance K+ channels, to block K+ channels in glioma cells, and antioxidant N-acetyl-l-cysteine (NAC) to inhibit production of intracellular reactive oxygen species (ROS). TEA showed an antiproliferation effect on C6 and U87 glioma cells in a time-dependent manner, which was accompanied by an increased intracellular ROS level. Antioxidant NAC pretreatment reversed TEA-mediated antiproliferation and restored ROS level. TEA treatment also caused significant increases in mRNA and protein levels of tumor-suppressor proteins p53 and p21, and the upregulation was attenuated by pretreatment of NAC. Our results suggest that K+ channel activity significantly contributes to brain glioma cell proliferation via increasing ROS, and it might be an upstream factor triggering the activation of the p53/p21Cip1-dependent signaling pathway, consequently leading to glioma cell cycle arrest.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831770163 ◽  
Author(s):  
Niharika Sinha ◽  
Prashanta Kumar Panda ◽  
Prajna Paramita Naik ◽  
Tapas K Maiti ◽  
Sujit K Bhutia

The accumulating evidences show that Abrus agglutinin, a plant lectin, displays a broad range of anticancer activity including cancer-specific induction of apoptosis; however, the underlying molecular mechanism of Abrus agglutinin–induced oral cancer stem cell elimination remains elusive. Our data documented that Abrus agglutinin effectively downregulated the CD44+ expression with the increased CD44− population in different oral cancer cells. After 24-h Abrus agglutinin treatment, FaDu cells were quantified for orosphere formation in ultra-low attachment plates and data showed that Abrus agglutinin inhibited the number and size of orosphere in a dose-dependent manner in FaDu cells. Furthermore, Abrus agglutinin hindered the plasticity of FaDu orospheres as supported by reduced sphere formation and downregulated the self-renewal property via inhibition of Wnt-β-catenin signaling pathway. Introduction of LiCl, a glycogen synthase kinase 3β inhibitor, rescued the Abrus agglutinin–stimulated inhibition of β-catenin and phosphorylated glycogen synthase kinase 3β in FaDu cell–derived orospheres confirming importance of Wnt signaling in Abrus agglutinin–mediated inhibition of stemness. In this connection, our data showed that Abrus agglutinin restrained proliferation and induced apoptosis in FaDu-derived cancer stem cells in dose-dependent manner. Moreover, western blot data demonstrated that Abrus agglutinin increased the Bax/Bcl-2 ratio with activation of poly(adenosine diphosphate–ribose) polymerase and caspase-3 favoring apoptosis induction in orospheres. Abrus agglutinin induced reactive oxygen species accumulation in orospheres and pretreatment of N-acetyl cysteine, and a reactive oxygen species scavenger inhibited Abrus agglutinin–mediated caspase-3 activity and β-catenin expression indicating reactive oxygen species as a principal regulator of Wnt signaling and apoptosis. In conclusion, Abrus agglutinin has a potential role as an integrative therapeutic approach for combating oral cancer through targeting self-renewability of orospheres via reactive oxygen species–mediated apoptosis.


2002 ◽  
Vol 46 (10) ◽  
pp. 3113-3117 ◽  
Author(s):  
Daisuke Kobayashi ◽  
Kei Kondo ◽  
Nobuyuki Uehara ◽  
Seiko Otokozawa ◽  
Naoki Tsuji ◽  
...  

ABSTRACT We investigated the significance of endogenous reactive oxygen species (ROS) produced by fungi treated with miconazole. ROS production in Candida albicans was measured by a real-time fluorogenic assay. The level of ROS production was increased by miconazole at the MIC (0.125 μg/ml) and was enhanced further in a dose-dependent manner, with a fourfold increase detected when miconazole was used at 12.5 μg/ml. This increase in the level of ROS production was completely inhibited by pyrrolidinedithiocarbamate (PDTC), an antioxidant, at 10 μM. In a colony formation assay, the decrease in cell viability associated with miconazole treatment was significantly prevented by addition of PDTC. Moreover, the level of ROS production by 10 clinical isolates of Candida species was inversely correlated with the miconazole MIC (r = −0.8818; P < 0.01). These results indicate that ROS production is important to the antifungal activity of miconazole.


2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095366
Author(s):  
Yun-Hee Rhee ◽  
Ye Kyu Park ◽  
Jong-Soo Kim

The aim of this study was to investigate the anti-inflammatory properties of Pandanus conoideus Lamk (red fruit oil [RFO]) and establish the signal pathway of the leading compounds. RAW 264.7 murine macrophage cells were used with lipopolysaccharide (LPS). Cell viability and the pro-inflammatory factors were investigated using MTT assay, real-time polymerase chain reaction (PCR), western blot analysis, and enzyme-linked immunosorbent assay. The quantification of leading compounds in RFO was performed using high-performance liquid chromatography (HPLC). RFO did not reduce RAW 264.7 cell viability. RFO significantly reduced the production of nitric oxide (NO), cyclooxygenase-2, and prostaglandin E2, and both the protein level and mRNA level of inducible NO synthase in LPS-induced macrophages. RFO also regulated the reactive oxygen species (ROS) in LPS-induced macrophages. RFO attenuated the translocation of the nuclear factor κB (NF-κB) p65 subunit, phosphorylation of I-κB, p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase (JNK) in a dose-dependent manner. HPLC analysis determined that 1 g of RFO had 14.05 ± 0.8 mg of β-cryptoxanthin and 7.4 ± 0.7 mg of β-carotene. In conclusion, RFO provides an anti-inflammatory effect by regulating ROS and NF-κB through mitogen-activated protein kinase due to antioxidant activity.


2015 ◽  
Vol 35 (6) ◽  
pp. 598-607 ◽  
Author(s):  
S-W Li ◽  
C-M Liu ◽  
J Guo ◽  
AM Marcondes ◽  
J Deeg ◽  
...  

Background: Hepatic iron overload is common in patients with myelodysplastic syndromes undergoing hematopoietic cell transplantation (HCT) and may predispose to peri- and post-HCT toxicity. To better understand the mechanisms of iron overload-induced liver injury, we examined the effects of iron overload induced by ferric ammonium citrate (FAC) on oxidative stress and apoptosis signaling pathway in human hepatic cell line HH4. Methods and Results: Hepatic HH4 cells were exposed to FAC to force iron uptake, and cellular responses were determined. Incubation with 5 mM FAC resulted in increased intracellular iron content in a time-dependent manner. High concentration of FAC impaired cell viability and increased level of reactive oxygen species (ROS), and addition of antioxidant reagent such as glutathione or N-acetylcysteine dramatically reduced FAC-induced intracellular ROS generation. FAC overload significantly increased the phosphorylation of inhibitor of κB-α, p38 mitogen-activated protein kinase (MAPK), and nuclear factor κ light chain enhancer of activated B cells (NF-κB) p65 and promoted the nuclear translocation of NF-κB p65. Knockdown of Fas and Bid expression by small interfering RNA in iron-treated HH4 cells resulted in restoration of cell viability. Conclusions: We reported that FAC treatment is capable of inducing both extrinsic death receptor and intrinsic mitochondrial signaling pathway-mediated HH4 cells apoptosis through ROS-activated p38 MAPK and NF-κB pathways.


2017 ◽  
Vol 42 (2) ◽  
pp. 685-696 ◽  
Author(s):  
Xiaoxv Dong ◽  
Jing Fu ◽  
Xingbin Yin ◽  
Changhai Qu ◽  
Chunjing Yang ◽  
...  

Background/Aims: Aloe-emodin (1,8-dihydroxy-3-hydroxymethyl-anthraquinone), an anthraquinone active compounds, is isolated from some traditional medicinal plants such as Rheum palmatum L. and Cassia occidentalis, which induce hepatotoxicity in rats. The aim of this study was to determine potential cytotoxic effects of aloe-emodin on HepaRG cells and to define the underlying mechanism. Methods: MTT was used to evaluate cell viability. Apoptotic cell death was analyzed via Annexin V-FITC/PI double staining. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were determined by flow cytometry, while the expression of apoptosis-related proteins was determined by Western blot analysis. Results: Treatment with aloe-emodin significantly reduced cell viability and induced apoptosis in HepaRG cells in a dose- and time-dependent manner. It provoked ROS generation and depolarization of MMP in HepaRG cells when compared with controls. Aloe-emodin dose-dependently increased release of mitochondrial cytochrome c, and levels of Fas, p53, p21, Bax/Bcl-2 ratio, as well as activation of caspase-3, caspase-8, caspase-9, and subsequent cleavage of poly(ADP-ribose)polymerase (PARP). It also induced S-phase cell cycle arrest by increasing the expression of p21 and cyclin E proteins while significantly decreasing the expression of cyclin A and CDK2. Conclusion: These results suggest that aloe-emodin inhibits cell proliferation and induces apoptosis in HepaRG cells, most probably through a mechanism involving both Fas death pathway and the mitochondrial pathway by generation of ROS. These findings underscore the need for risk assessment of human exposure to aloe-emodin.


Reproduction ◽  
2015 ◽  
Vol 149 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Ronit Yalu ◽  
Adepeju Esther Oyesiji ◽  
Iris Eisenberg ◽  
Tal Imbar ◽  
Rina Meidan

Hypoxia-inducible factor 1 alpha (HIF1A) and endothelin 2 (EDN2) are transiently expressed during the same time window in the developing corpus luteum (CL). In this study, we sought to investigate the involvement of LH/cAMP, reactive oxygen species (ROS), and a hypoxia-mimetic compound (CoCl2) on HIF1A expression and how it affected EDN2 levels, using transformed human granulosa cells (thGCs) and primary bovine granulosa cells (GCs). CoCl2 elevated HIF1A protein levels in thGCs in a dose-dependent manner. Forskolin alone had no significant effect; however, forskolin and CoCl2 together further induced HIF1A protein and EDN2 mRNA expression in thGCs. Similarly, in primary GCs, LH with CoCl2 synergistically augmented HIF1A protein levels, which resulted in higher expression of EDN2 and another well-known hypoxia-inducible gene, VEGF (VEGFA). Importantly, LH alone elevated HIF1A mRNA but not its protein. The successful knockdown of HIF1A in thGCs using siRNA abolished hypoxia-induced EDN2 and also the additive effect of forskolin and CoCl2. We then examined the roles of ROS in thGCs: hydrogen peroxide (20 and 50 μM) elevated HIF1A protein as well as the expression of EDN2, implying that induction of HIF1A protein levels is sufficient to stimulate the expression of EDN2 (and VEGF) in normoxia. A broad-range ROS scavenger, butylated hydroxyanisole, inhibited CoCl2-induced HIF1A protein with a concomitant reduction in the mRNA expression of EDN2 and VEGF in thGCs. The results obtained in this study suggest that HIF1A, induced by various stimuli, is an essential mediator of EDN2 mRNA expression. The results may also explain the rise in the levels of HIF1A-dependent genes (EDN2 and VEGF) in the developing CL.


2001 ◽  
Vol 31 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Tobias W. Fischer ◽  
Georg Scholz ◽  
Brunhilde Knöll ◽  
Uta-Christina Hipler ◽  
Peter Elsner

2007 ◽  
Vol 85 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Xu-Bin Jing ◽  
Xian-Bin Cai ◽  
Hui Hu ◽  
Su-Zuan Chen ◽  
Bin-Ming Chen ◽  
...  

cis-Diamminedichloroplatinum (CDDP), commonly know as cisplatin, is a well known DNA-damaging agent, which is highly active in suppressing the proliferation of tumor cells. However, it is not clear that CDDP can induce growth inhibition of esophagus cancer cells. Using the cell line EC-109 from the esophagus, we found that CDDP would induce apoptotic responses. The addition of CDDP to cells led to the inhibition of growth in a time- and dose-dependent manner. CDDP generated reactive oxygen species (ROSs) in cells, which brought about a reduction in the intracellular mitochondrial transmembrane potential (Δψm), leading to apoptosis. Our findings demonstrate that ROSs, and the resulting oxidative stress, play a pivotal role in apoptosis. Preincubation of EC-109 cells with the hydrogen-peroxide-scavenging enzyme catalase partially inhibited the following: (i) the production of ROS; (ii) the disruption of the Δψm; and (iii) apoptosis. These results indicate that the enhancement of the generation of ROS and the disruption of Δψm are events involved in the apoptotic pathway of EC-109 induced by CDDP.


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