scholarly journals Baicalin Augments Hyperthermia-Induced Apoptosis in U937 Cells and Modulates the MAPK Pathway via ROS Generation

2018 ◽  
Vol 45 (6) ◽  
pp. 2444-2460 ◽  
Author(s):  
Shahbaz Ahmad Zakki ◽  
Zheng-Guo Cui ◽  
Lu Sun ◽  
Qian-Wen Feng ◽  
Meng-Ling Li ◽  
...  

Background/Aims: Hyperthermia is a widely used therapeutic tool for cancer therapy and a well-known inducer of apoptosis. Although the flavonoid compound baicalin (BCN) is a potent anticancer agent for several human carcinomas, it is less potent in the human U937 myelomonocytic leukemia cell line. To explore any enhancing effects of BCN on hyperthermia-induced apoptosis, this study investigated the combined effects and apoptotic mechanisms of hyperthermia and BCN in U937 cells. Methods: U937 cells were heat treated at 44ºC for 12 min with or without pre-treatment with BCN (10-50 µM) and then incubated for 6 h at 37 ºC with 5% CO2 and 95% air. Cell viability was analyzed by Trypan blue exclusion assay. Apoptosis was examined by DNA fragmentation, fluorescence microscopy and flow cytometry. Generation of mitochondrial trans-membrane potential (MMP), mitochondrial calcium, and reactive oxygen species (ROS) was also detected by flow cytometry. The expression of proteins related to apoptosis and signaling pathways was determined by western blotting. Results: Hyperthermia alone did not reduce cell viability or induce notable levels of apoptosis, but combined hyperthermia and BCN treatment markedly augmented apoptosis by upregulating proapoptotic proteins and suppressing antiapoptotic proteins, culminating in caspase-3 activation. Mitochondrial transmembrane potential was significantly decreased, and generation of reactive oxygen species (ROS) and suppression of antioxidant enzymes were marked. Furthermore, with the combined treatment, the phosphorylated forms of JNK and p38 showed increased expression, whereas AKT was dephosphorylated. JNK-IN-8 (a JNK inhibitor) and NAC (a ROS scavenger) abrogated the apoptotic effects of the combined treatment, significantly protecting the cells and indicating the involvement of high ROS generation and the MAPK pathway in the underlying molecular mechanism. Conclusion: This study provides compelling evidence that hyperthermia, in combination with BCN, is a promising therapeutic strategy for enhancement of apoptosis and suggest a promising therapeutic approach for cancer.

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
Shashank Hambarde ◽  
Martyn Sharpe ◽  
David Baskin ◽  
Santosh Helekar

Abstract Noninvasive cancer therapy with minimal side effects would be ideal for improving patient outcome in the clinic. We have developed a novel therapy using strong rotating magnets mounted on a helmet. They generate oscillating magnetic fields (OMF) that penetrate through the skull and cover the entire brain. We have demonstrated that OMF can effectively kill patient derived glioblastoma (GBM) cells in cell culture without having cytotoxic effects on cortical neurons and normal human astrocytes (NHA). Exposure of GBM cells to OMF reduced the cell viability by 33% in comparison to sham-treated cells (p< 0.001), while not affecting NHA cell viability. Time lapse video-microscopy for 16 h after OMF exposure showed a marked elevation of mitochondrial reactive oxygen species (ROS), and rapid apoptosis of GBM cells due to activation of caspase 3. Addition of a potent antioxidant vitamin E analog Trolox effectively blocked OMF-induced GBM cell death. Furthermore, OMF significantly potentiated the cytotoxic effect of the pro-oxidant Benzylamine. The results of our studies demonstrate that OMF-induced cell death is mediated by ROS generation. These results demonstrate a potent oncolytic effect on GBM cells that is novel and unrelated to any previously described therapy, including a very different mechanism of action and different technology compared to Optune therapy. The effect is very powerful, and unlike Optune, can be seen within hours after initiation of treatment. We believe that this technology holds great promise for new, effective and nontoxic treatment of glioblastoma.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4370-4370
Author(s):  
Guo Kunyuan ◽  
Miaorong She ◽  
Haiyan Hu ◽  
Xinqing Niu ◽  
Sanfang Tu ◽  
...  

Abstract 2-Methoxyestradiol (2-ME) is a new anticancer agent currently under investigation for treatment of leukemia. We evaluated the effects of 2-ME-induced apoptosis in two myeloid leukemia cell lines (U937 and HL-60) in association with reactive oxygen species (ROS) generation. We found that 2-ME resulted in viability decrease in a dose-dependent manner, generated ROS: nitric oxide and superoxide anions, and mitochondria damage. 2-ME-induced apoptosis correlated with increase in ROS. Quenching of ROS with N-acetyl-L-cysteine protected leukemia cells from the cytotoxicity of 2-ME and prevented apoptosis induction by 2-ME. Furthermore, addition of manumycin, a farnesyltransferase inhibitor, demonstrated by our previous studies that induced apoptosis of leukemic cells and induced ROS, significantly enhanced the apoptosis-induced by 2-ME. In conclusion, cellular ROS generation play an important role in the cytotoxic effect of 2-ME. It is possible to use ROS-generation agents such as manumycin to enhance the antileukemic effect. Such a combination strategy need the further in vivo justify and may have potential clinical application.


Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2970-2972 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Jessica F. White ◽  
John Deighton ◽  
Sarah R. Walmsley ◽  
Edwin R. Chilvers

Abstract In most cell types constitutive and ligand-induced apoptosis is a caspase-dependent process. In neutrophils, however, the broad-spectrum caspase inhibitor z-VAD-fmk enhances tumor necrosis factor-α (TNFα)-induced cell death, and this has been interpreted as evidence for caspase-dependent and -independent cell death pathways. Our aim was to determine the specificity of the effect of z-VAD-fmk in neutrophils and define the potential mechanism of action. While confirming that z-VAD-fmk (> 100 μM) enhances TNFα-induced neutrophil apoptosis, lower concentrations (1-30 μM) completely blocked TNFα-stimulated apoptosis. Boc-D-fmk, a similar broad-spectrum caspase inhibitor, and z-IETD-fmk, a selective caspase-8 inhibitor, caused a concentration-dependent inhibition of only TNFα-stimulated apoptosis. Moreover, the caspase-9 inhibitor, Ac-LEHD-cmk, had no effect on TNFα-induced apoptosis, and z-VAD-fmk and Boc-D-fmk inhibited TNFα-stimulated reactive oxygen species (ROS) generation. These data suggest that TNFα-induced apoptosis in neutrophils is fully caspase dependent and uses a mitochondrial-independent pathway and that the proapoptotic effects of z-VAD-fmk are compound specific and ROS independent.


2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Sun ◽  
Tongsheng Chen ◽  
Xiaoping Wang ◽  
Yun Chen ◽  
Xunbin Wei

Bufalin has been shown to induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. In this study, we used the confocal fluorescence microscopy (CFM) to monitor the spatio-temporal dynamics of reactive oxygen species (ROS) production, Bax translocation and caspase-3 activation during bufalin-induced apoptosis in living human lung adenocarcinoma (ASTC-a-1) cells. Bufalin induced ROS production and apoptotic cell death, demonstrated by Hoechst 33258 staining as well as flow cytometry analysis. Bax redistributed from cytosol to mitochondria from 12 to 48 h after bufalin treatment in living cells expressed with green fluorescent protein Bax. Treatment with the antioxidantN-acetyl-cysteine (NAC), a ROS scavenger, inhibited ROS generation and Bax translocation and led to a significant protection against bufalin-induced apoptosis. Our results also revealed that bufalin induced a prominent increase of caspase-3 activation blocked potently by NAC. Taken together, bufalin induced ROS-mediated Bax translocation, mitochondrial permeability transition and caspase-3 activation, implying that bufalin induced apoptosis via ROS-dependent mitochondrial death pathway in ASTC-a-1 cells.


2020 ◽  
Vol 27 (9) ◽  
pp. 860-869 ◽  
Author(s):  
Mingning Qiu ◽  
Jie Liu ◽  
Yongxia Su ◽  
Jianjun Liu ◽  
Chenchen Wu ◽  
...  

Background: Ovarian cancer is the most lethal gynecologic malignancy worldwide with poor prognosis owing to chemotherapy resistance and cancer relapse. Hence, there is an urgent need to develop novel anticancer agents against ovarian cancer. Objective: The aim of this research is to investigate the possible anticancer activity of aloperine, an active ingredient from a traditional Chinese medicine Sophora alopecuroides, and to explore the possible Reactive Oxygen Species (ROS)-related mechanism. Methods: Cell viability, cytotoxicity, apoptosis, ROS generation, and oxidant stress indicators were analyzed. Results: Our results demonstrated that aloperine significantly induced inhibition of cell viability, promoted cytotoxicity and mitochondrial-related apoptosis, and increased ROS generation in ovarian cancer cells. Furthermore, the antioxidant α-lipoic acid reversed apoptosis in aloperinetreated cells. In addition, we identified hydrogen peroxide as the main type of ROS, and the antioxidant catalase suppressed the apoptotic inducing effect of aloperine whereas hydrogen peroxide supplement exacerbated the effect of aloperine in ovarian cancer cells. Conclusion: Taken together, our results indicated that aloperine could exert anti-ovarian cancer cell activity through a reactive oxygen species activation mechanism and suggested aloperine as a potential agent against ovarian cancer.


2017 ◽  
Vol 42 (5) ◽  
pp. 1812-1821 ◽  
Author(s):  
Jilong Zou ◽  
Yan Zhang ◽  
Jiabing Sun ◽  
Xiaoyan Wang ◽  
Hualei Tu ◽  
...  

Background/Aims: Osteosarcoma is the predominant form of primary bone malignancy. Although the combinational application of neoadjuvant chemotherapy and surgical resection significantly increases the survival rate, the therapeutic outcome remains unsatisfactory. Deoxyelephantopin (DET), an active ingredient of Elephantopus scaber, has been reported to have an anti-tumor effect in recent publications. This study aimed to investigate whether DET has antineoplastic effects on osteosarcoma cells and its underlying mechanism. Methods: Cell viability and morphological changes were assessed by MTT and Live/dead assays. Cell apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential were detected utilizing Annexin V-FITC/PI double staining, DCFH-DA and JC-1 probes, respectively. Autophagy was detected by mRFP-GFP-LC3 adenovirus transfection and western blot. Results: DET dose-dependently reduced the viability of osteosarcoma cells following the increase in intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) reversed this effect. Furthermore, DET induced mitochondrial apoptosis. Depolarized cells were increased, and apoptosis-related proteins, such as Bax, Bcl-2, cleaved caspase-9, cleaved caspase-3 and cleaved ploy ADP-ribose polymerase, were activated. Additionally, we found that DET could induce autophagy in osteosarcoma cells, but autophagy inhibition did not affect the decrease in cell viability. Conclusion: DET induced apoptosis in osteosarcoma cells through ROS generation, mitochondrial dysfunction and caspase activation; in addition, autophagy was involved in the effects of DET on osteosarcoma cells.


2017 ◽  
Vol 42 (3) ◽  
pp. 889-900 ◽  
Author(s):  
Hai-Li Huang ◽  
Ya-Peng Shi ◽  
Hui-Juan He ◽  
Ya-Hong Wang ◽  
Ting Chen ◽  
...  

Background: Our previous study identified a novel microRNA, miR-4673, which is upregulated in A549 cells exposed to paclitaxel (PTX). In this study, we investigated the role of miR-4673 in PTX-induced cytotoxicity. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, apoptosis assay, 5,5’,6,6’-Tetrachloro-1,1’,3,3’-tetraethyl-imidacarbocyanine iodide (JC-1) staining and 2’,7’-Dichlorofluorescein (DCFH) staining were used to evaluate cell viability, apoptosis, mitochondrial membrane potential (MMP) loss and reactive oxygen species (ROS) generation in A549 and H1299 cells. Bioinformatics analysis and Luciferase reporter assay were used to explore whether 8-oxoguanine-DNA glycosylase-1 (OGG1) is a target gene of miR-4673. Results: Enforced expression of miR-4673 decreased cell viability and increased PTX-induced apoptosis, MMP loss and reactive oxygen species (ROS) generation in A549 and H1299 cells. Bioinformatics analysis, which was used to identify potential target of miR-4673, revealed a binding site of miR-4673 in 3’UTR of OGG1. Luciferase reporters assays showed that miR-4673 specifically binds to ‘CUGUUGA’ in 3’UTR of OGG1. Enforced expression of miR-4673 decreased accumulation of OGG1. In addition, silencing OGG1 enhanced inhibitory effects of PTX on apoptosis, MMP loss and ROS generation, which is similar to effects of miR-4673. Moreover, enforced expression of OGG1 compromised promoting effects of miR-4673 on PTX-induced apoptosis, MMP loss and ROS generation. Conclusion: miR-4673 modulates PTX-induced apoptosis, MMP loss and ROS generation by targeting OGG1.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2509-2509
Author(s):  
Ulrike Heider ◽  
Martin Kaiser ◽  
Ivana Zavrski ◽  
Jan Sterz ◽  
Christian Jakob ◽  
...  

Abstract Mantle cell lymphoma (MCL) is an incurable B cell lymphoma and novel treatment strategies are urgently needed. Proteasome inhibitors, e.g. bortezomib, act by targeting the catalytic 20S core of the proteasome and induce apoptosis in tumor cells. Among other mechanisms, they lead to cytoplasmic accumulation of the IκBa protein, resulting in a reduced NF-κB activity. Histone deacetylase inhibitors (HDAI), e.g. SAHA, promote histone acetylation, chromatin uncoiling, and transcription of a variety of genes. Previous studies have indicated that HDAIs also interfere with NF-κB signaling. Since NF-κB is constitutively activated MCL cells and plays a major role in a variety of cellular processes, we hypothesized synergist effects of bortezomib and HDAI in MCL cells. Human mantle cell lymphoma cell lines (JeKo-1 and Granta-519) were exposed to bortezomib and/ or SAHA for 4 to 48 hours. Cell viability and apoptosis were quantified by the MTT and annexin-V assay, respectively. The effect of the combination of both agents was analyzed using the median effect method of Chou and Talalay. Reactive oxygen species (ROS) were quantified by the fluorophore H2DCFDA. The functional role of ROS generation was assessed using the free radical scavenger N-acetyl-l-cysteine (LNAC). In addition, activated caspases, proteasome- and NF-κB activity were quantified. After 48 hours of incubation, IC50 of SAHA and bortezomib were noted at 0.8μM and 7.7nm in JeKo-1 cells and at 3.9μM and 5.7nm in Granta-519 cells, respectively. Combined incubation resulted in synergistic cytotoxic effects, as indicated by CI values <1. This was accompanied by an increase of caspase-3, -8 and -9 activity. In addition, coexposure of bortezomib and SAHA led to an enhanced ROS generation (5.4 fold in Jeko-1 and 9.2 fold in Granta-519 as compared to untreated controls), while the agents alone only modestly induced reactive oxygen species. LNAC could block the ROS generation and reduced the apoptosis significantly. As expected, bortezomib reduced the NF-κB activity. Interestingly, exposure to SAHA led to an increase of NF-κB activity after 4 hours and a decrease after 24 hours. The combination of both drugs resulted in a decrease of NF-κB activity. Moreover, combined treatment with bortezomib and SAHA resulted in a marked reduction of proteasome activity that was more pronounced than the proteasome inhibition by the single agents. In conclusion, this is the first report giving evidence that SAHA and bortezomib synergistically induce apoptosis in mantle cell lymphoma cells through the generation of reactive oxygen species and disruption of the NF-κB pathway. Our data provide a framework for clinical studies with the combination of both agents in patients with mantle cell lymphoma.


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