scholarly journals Molecular Mechanisms Underlying the Synergism of Erib and Hht in Treating t(8;21) AML with C-KIT mutations

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2332-2332
Author(s):  
Bing Chen ◽  
Xin-Jie Chen ◽  
Sai-Juan Chen

Abstract AML1-ETO oncoprotein (AE) resulting from t(8;21)(q22;q22) translocation is known to play a pivotal role in leukemogenesis of t(8;21) AML, yet the activating mutations or over-expression of C-KIT occur in half of the AML patients with t(8;21). Animal models have proven that activating C-KIT mutations cooperate with AE in causing overt AML. The aberrant C-KIT expression was thus thought to be the major “second hit” in stepwise leukemogenesis of t(8;21) AML. Previous studies have demonstrated that Eriocalyxin B (EriB), a diterpenoid extracted from Isodon eriocalyx, induced apoptosis in t(8;21) leukemia cells through the NF-κB and MAPK signaling pathways and triggered degradation of AE dependent on caspase-3. By targeting AML1-ETO oncoprotein and activating apoptosis pathways simultaneously, EriB has potential to treat the t(8;21) leukemia. In this study, we observed the synergistic effect of EriB and the chemotherapy drug Homoharringtonine (HHT) on Kasumi-1, an AML cell line harboring t(8;21) and C-KIT mutations. Compared with using EriB or HHT alone, the combination of EriB and HHT (E+H) exhibited a higher efficacy to induce apoptosis and inhibit proliferation of Kasumi-1 cells. Data further showed that HHT enhanced the AE degradation caused by EriB in a dose/time-dependent manner. In addition, HHT significantly decreased the expression of C-KIT in Kasumi-1 cells, and the combination with EriB markedly enhanced this effect. Mechanism study revealed that E+H combination down-regulated the expression of transcriptional factor Sp1 through up-regulating miR-29b, separated Sp1 protein from Sp1/NF-κB complex, and released the Sp1/NF-κB complex from the C-KIT promoter. These data point to a mechanism involving Sp1/NF-κB/miR-29b regulatory network whereby E+H combination down-regulate C-KIT mRNA expression. In addition, HHT induced a proteasome-mediated degradation of C-KIT protein, which was further enhanced by EriB. From these observations, we conclude that the combined use of EriB and HHT might offer a potential therapeutic avenue for t(8;21) AML with C-KIT mutations. Disclosures No relevant conflicts of interest to declare.

2020 ◽  
Vol 22 (1) ◽  
pp. 307
Author(s):  
Hyun-Jung Park ◽  
Ran Lee ◽  
Hyunjin Yoo ◽  
Kwonho Hong ◽  
Hyuk Song

Nonylphenol (NP) is an endocrine-disruptor chemical that negatively affects reproductive health. Testes exposure to NP results in testicular structure disruption and a reduction in testicular size and testosterone levels. However, the effects of NP on spermatogonia in testes have not been fully elucidated. In this study, the molecular mechanisms of NP in GC-1 spermatogonia (spg) cells were investigated. We found that cell viability significantly decreased and apoptosis increased in a dose-dependent manner when GC-1 spg cells were exposed to NP. Furthermore, the expression levels of the pro-apoptotic proteins increased, whereas anti-apoptosis markers decreased in NP-exposed GC-1 spg cells. We also found that NP increased reactive oxygen species (ROS) generation, suggesting that ROS-induced activation of the MAPK signaling pathway is the molecular mechanism of NP-induced apoptosis in GC-1 spg cells. Thus, NP could induce c-Jun phosphorylation; dose-dependent expression of JNK, MKK4, p53, and p38; and the subsequent inhibition of ERK1/2 and MEK1/2 phosphorylation. The genes involved in apoptosis and JNK signaling were also upregulated in GC-1 spg cells treated with NP compared to those in the controls. Our findings suggest that NP induces apoptosis through ROS/JNK signaling in GC-1 spg cells.


2014 ◽  
Vol 84 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Amin F. Majdalawieh ◽  
Hyo-Sung Ro

Background: Foam cell formation resulting from disrupted macrophage cholesterol efflux, which is triggered by PPARγ1 and LXRα, is a hallmark of atherosclerosis. Sesamin and sesame oil exert anti-atherogenic effects in vivo. However, the exact molecular mechanisms underlying such effects are not fully understood. Aim: This study examines the potential effects of sesamin (0, 25, 50, 75, 100 μM) on PPARγ1 and LXRα expression and transcriptional activity as well as macrophage cholesterol efflux. Methods: PPARγ1 and LXRα expression and transcriptional activity are assessed by luciferase reporter assays. Macrophage cholesterol efflux is evaluated by ApoAI-specific cholesterol efflux assays. Results: The 50 μM, 75 μM, and 100 μM concentrations of sesamin up-regulated the expression of PPARγ1 (p< 0.001, p < 0.001, p < 0.001, respectively) and LXRα (p = 0.002, p < 0.001, p < 0.001, respectively) in a concentration-dependent manner. Moreover, 75 μM and 100 μM concentrations of sesamin led to 5.2-fold (p < 0.001) and 6.0-fold (p<0.001) increases in PPAR transcriptional activity and 3.9-fold (p< 0.001) and 4.2-fold (p < 0.001) increases in LXR transcriptional activity, respectively, in a concentration- and time-dependent manner via MAPK signaling. Consistently, 50 μM, 75 μM, and 100 μM concentrations of sesamin improved macrophage cholesterol efflux by 2.7-fold (p < 0.001), 4.2-fold (p < 0.001), and 4.2-fold (p < 0.001), respectively, via MAPK signaling. Conclusion: Our findings shed light on the molecular mechanism(s) underlying sesamin’s anti-atherogenic effects, which seem to be due, at least in part, to its ability to up-regulate PPARγ1 and LXRα expression and transcriptional activity, improving macrophage cholesterol efflux. We anticipate that sesamin may be used as a therapeutic agent for treating atherosclerosis.


2018 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Aikebaier Maimaiti ◽  
Amier Aili ◽  
Hureshitanmu Kuerban ◽  
Xuejun Li

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1731-1731
Author(s):  
Mercè de Frias ◽  
Daniel Iglesias-Serret ◽  
Ana M Cosialls ◽  
Llorenç Coll-Mulet ◽  
Antonio F Santidrián ◽  
...  

Abstract Abstract 1731 Poster Board I-757 Phosphatidylinositol-3-kinase (PI3K)/Akt pathway has been described to be critical in the survival of chronic lymphocytic leukemia (CLL) cells. Here, we have analyzed the effect of two selective chemical inhibitors of Akt (Akti-1/2 and A-443654) in the survival of CLL cells. We studied by cytometric analysis the cytotoxic effects of Akt inhibitors on peripheral B and T lymphocytes from patients with CLL and from healthy donors. Both inhibitors induced apoptosis in CLL cells in a dose-dependent manner. Moreover, B cells from CLL samples were more sensitive to Akt inhibitors than T cells from CLL samples, and B or T cells from healthy donors. Survival factors for CLL cells, such as IL-4 and SDF-1a, were not able to block the apoptosis induced by both Akt inhibitors. We studied the changes induced by Akti-1/2 and A-443654 at mRNA level by performing reverse transcriptase multiplex ligation–dependent probe amplification (RT-MLPA). Akti-1/2 did not induce any change in the mRNA expression profile of genes involved in apoptosis, while A-443654 induced some changes, including an increase in NOXA and PUMA mRNA levels, suggesting the existence of additional targets for A-443654. We also studied the changes induced by both Akt inhibitors in some BCL-2 protein family members on CLL cells by Western blot. Both inhibitors induced an increase in PUMA and NOXA protein levels, and a decrease in MCL-1 protein level. Moreover, Akti-1/2 and A-443654 induced apoptosis irrespective of TP53 status. These results demonstrate that Akt inhibitors induce apoptosis of CLL cells and might be a new therapeutic option for the treatment of CLL. Disclosures No relevant conflicts of interest to declare.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jiao Peng ◽  
Ting-ting Zheng ◽  
Yue Liang ◽  
Li-fang Duan ◽  
Yao-dong Zhang ◽  
...  

To protect against oxidative stress-induced apoptosis in lens epithelial cells is a potential strategy in preventing cataract formation. The present study aimed at studying the protective effect and underlying mechanisms of p-coumaric acid (p-CA) on hydrogen peroxide- (H2O2-) induced apoptosis in human lens epithelial (HLE) cells (SRA 01–04). Cells were pretreated with p-CA at a concentration of 3, 10, and 30 μM before the treatment of H2O2 (275 μM). Results showed that pretreatment with p-CA significantly protected against H2O2-induced cell death in a dose-dependent manner, as well as downregulating the expressions of both cleaved caspase-3 and cleaved caspase-9 in HLE cells. Moreover, p-CA also greatly suppressed H2O2-induced intracellular ROS production and mitochondrial membrane potential loss and elevated the activities of T-SOD, CAT, and GSH-Px of H2O2-treated cells. As well, in vitro study showed that p-CA also suppressed H2O2-induced phosphorylation of p-38, ERK, and JNK in HLE cells. These findings demonstrate that p-CA suppresses H2O2-induced HLE cell apoptosis through modulating MAPK signaling pathways and suggest that p-CA has a potential therapeutic role in the prevention of cataract.


2019 ◽  
Vol 13 (1) ◽  
pp. 489-496 ◽  
Author(s):  
Jun Jiang ◽  
Nanyang Zhou ◽  
Pian Ying ◽  
Ting Zhang ◽  
Ruojia Liang ◽  
...  

AbstractEmodin, a major component of rhubarb, has anti-tumor effects in a variety of cancers, influencing multiple steps of tumor development through modulating several signaling pathways. The aim of this study is to examine the effect of emodin on cell apoptosis and explore the underlying mechanisms in human endometrial cancer cells. Here we report that emodin can inhibit KLE cell proliferation and induce apoptosis in a time- and dose-dependent manner. Western blot assay found that emodin was involved in MAPK and PI3K/Akt signaling pathways. Specifically, emodin significantly suppressed the phosphorylation of AKT, and enhanced the phosphorylation of MAPK pathways. Furthermore, the generation of reactive oxygen species (ROS) was up-regulated in KLE cells upon treatment with emodin, while the anti-oxidant agent N-acetyl cysteine (NAC) can inhibit emodin-induced apoptosis and promote the activation of AKT and Bcl-2. Taken together, we revealed that emodin may induce apoptosis in KLE cells through regulating the PI3K/AKT and MAPK signaling pathways, indicating the importance of emodin as an anti-tumor agent.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Wasitta Rachakhom ◽  
Patompong Khaw-on ◽  
Wilart Pompimon ◽  
Ratana Banjerdpongchai

Dihydrochalcone derivatives are active compounds that have been purified from the Thai medicinal plant Cyathostemma argenteum. The objectives of this study were to investigate the effects of two dihydrochalcone derivatives on human breast cancer MDA-MB-231 and MCF-7 cell proliferation and to study the relevant mechanisms involved. The two dihydrochalcone derivatives are 4′,6′-dihydroxy-2′,4-dimethoxy-5′-(2″-hydroxybenzyl)dihydrochalcone (compound 1) and calomelanone (2′,6′-dihydroxy-4,4′-dimethoxydihydrochalcone, compound 2), both of which induced cytotoxicity toward both cell lines in a dose-dependent manner by using MTT assay. Treatment with both derivatives induced apoptosis as determined by annexin V-FITC/propidium iodide employing flow cytometry. The reduction of mitochondrial transmembrane potential (staining with 3,3′-dihexyloxacarbocyanine iodide, DiOC6, employing a flow cytometer) was established in the compound 1-treated cells. Compound 1 induced caspase-3, caspase-8, and caspase-9 activities in both cell lines, as has been determined by specific colorimetric substrates and a spectrophotometric microplate reader which indicated the involvement of both the extrinsic and intrinsic pathways. Calcium ion levels in mitochondrial and cytosolic compartments increased in compound 1-treated cells as detected by Rhod-2AM and Fluo-3AM intensity, respectively, indicating the involvement of the endoplasmic reticulum (ER) stress pathway. Compound 1 induced cell cycle arrest via enhanced atm and atr expressions and by upregulating proapoptotic proteins, namely, Bim, Bad, and tBid. Moreover, compound 1 significantly inhibited the EGFR/MAPK signaling pathway. In conclusion, compound 1 induced MDA-MB-231 and MCF-7 cell apoptosis via intrinsic, extrinsic, and ER stress pathways, whereas it ameliorated the EGFR/MAPK pathway in the MCF-7 cell line. Consequently, it is believed that compound 1 could be effectively developed for cancer treatments.


2019 ◽  
Vol 86 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Chenxu Zhao ◽  
Yazhou Wang ◽  
Xue Yuan ◽  
Guoquan Sun ◽  
Bingyu Shen ◽  
...  

AbstractSubacute ruminal acidosis (SARA) can increase the level of inflammation and induce rumenitis in dairy cows. Berberine (BBR) is the major active component of Rhizoma Coptidis, which is a type of Chinese anti-inflammatory drug for gastrointestinal diseases. The purpose of this study was to investigate the anti-inflammatory effects of BBR on lipopolysaccharide (LPS)-stimulated rumen epithelial cells (REC) and the underlying molecular mechanisms. REC were cultured and stimulated with LPS in the presence or absence of different concentrations of BBR. The results showed that cell viability was not affected by BBR. Moreover, BBR markedly decreased the concentrations and mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and interleukin-6 in the LPS-treated REC in a dose-dependent manner. Importantly, Western blotting analysis showed that BBR significantly suppressed the protein expression of toll-like receptor 4 (TLR4) and myeloid differentiation primary response protein (MyD88) and the phosphorylation of nuclear factor-κB (NF-κB), inhibitory kappa B (IκBα), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) in LPS-treated REC. Furthermore, the results of immunocytofluorescence showed that BBR significantly inhibited the nuclear translocation of NF-κB p65 induced by LPS treatment. In conclusion, the protective effects of BBR on LPS-induced inflammatory responses in REC may be due to its ability to suppress the TLR4-mediated NF-κB and MAPK signaling pathways. These findings suggest that BBR can be used as an anti-inflammatory drug to treat inflammation induced by SARA.


2015 ◽  
Vol 35 (6) ◽  
pp. 2233-2243 ◽  
Author(s):  
Yinglong Sa ◽  
Chao Li ◽  
Hongbin Li ◽  
Hailin Guo

Background/Aims: Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been reported to upregulate in urethral scar. However, the underlying molecular mechanisms remain undefined. Methods: Here, we studied levels of TIMP-1 and α-smooth muscle actin (α-SMA) in the fibroblasts isolated from urethral scar tissues, compared to the fibroblasts isolated from normal urethra. Then we either overexpressed TIMP-1, or inhibited TIMP-1 by lentiviruses carrying a transgene or a short hairpin small interfering RNA for TIMP-1 in human fibroblasts. We examined the effects of modulation of TIMP-1 on α-SMA, and on epithelial-mesenchymal transition (EMT)-related genes. We also studied the underlying mechanisms. Results: We detected significantly higher levels of TIMP-1 and α-smooth muscle actin (α-SMA) in the fibroblasts isolated from urethral scar tissues, compared to the fibroblasts isolated from normal urethra. Moreover, the levels of TIMP-1 and α-SMA strongly correlated. Moreover, we found that TIMP-1 significantly increased levels of α-SMA, transforming growth factor β 1 (TGFβ1), Collagen I and some other key factors related to an enhanced EMT, suggesting that TIMP-1 may induce transformation of fibroblasts into myofibroblasts to promote tissue EMT to enhance the formation of urethral scar. Moreover, increases in TIMP-1 also induced an increase in fibroblast cell growth and cell invasion, in an ERK/MAPK-signaling-dependent manner. Conclusion: Our study thus highlights a pivotal role of TIMP-1 in urethral scar formation.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Bin Chen ◽  
Ying Teng ◽  
Xingguang Zhang ◽  
Xiaofeng Lv ◽  
Yanling Yin

Both diabetes and hyperinsulinemia are confirmed risk factors for Alzheimer’s disease. Some researchers proposed that antidiabetic drugs may be used as disease-modifying therapies, such as metformin and thiazolidinediones, although more evidence was poorly supported. The aim of the current study is to investigate the role of metformin in Aβ-induced cytotoxicity and explore the underlying mechanisms. First, the experimental results show that metformin salvaged the neurons exposed to Aβin a concentration-dependent manner with MTT and LDH assay. Further, the phosphorylation levels of JNK, ERK1/2, and p38 MAPK were measured with western blot analysis. It was investigated that Aβincreased phospho-JNK significantly but had no effect on phospho-p38 MAPK and phospho-ERK1/2. Metformin decreased hyperphosphorylated JNK induced by Aβ; however, the protection of metformin against Aβwas blocked when anisomycin, the activator of JNK, was added to the medium, indicating that metformin performed its protection against Aβin a JNK-dependent way. In addition, it was observed that metformin protected the neurons via the suppression of apoptosis. Taken together, our findings demonstrate that metformin may have a positive effect on Aβ-induced cytotoxicity, which provides a preclinical strategy against AD for elders with diabetes.


Sign in / Sign up

Export Citation Format

Share Document