scholarly journals p53 Mediates Colistin-Induced Autophagy and Apoptosis in PC-12 Cells

2016 ◽  
Vol 60 (9) ◽  
pp. 5294-5301 ◽  
Author(s):  
Ling Zhang ◽  
Daoyuan Xie ◽  
Xueping Chen ◽  
Maria L. R. Hughes ◽  
Guozheng Jiang ◽  
...  
Keyword(s):  
Target Genes ◽  
Mammalian Target Of Rapamycin ◽  
Inhibitory Effect ◽  
Pc 12 Cells ◽  
Link Type ◽  
Cellular Events ◽  
Cycle Arrest ◽  
Induced Apoptosis ◽  
20 Nm ◽  
Amp Activated Protein Kinase

ABSTRACTThe mechanism of colistin-induced neurotoxicity is still unknown. Our recent study (L. Zhang, Y. H. Zhao, W. J. Ding, G. Z. Jiang, Z. Y. Lu, L. Li, J. L. Wang, J. Li, and J. C. Li, Antimicrob Agents Chemother 59:2189–2197, 2015,http://dx.doi.org/10.1128/AAC.04092-14; H. Jiang, J. C. Li, T. Zhou, C. H. Wang, H. Zhang, and H. Wang, Int J Mol Med 33:1298–1304, 2014,http://dx.doi.org/10.3892/ijmm.2014.1684) indicates that colistin induces autophagy and apoptosis in rat adrenal medulla PC-12 cells, and there is interplay between both cellular events. As an important cellular stress sensor, phosphoprotein p53 can trigger cell cycle arrest and apoptosis and regulate autophagy. The aim of the present study was to investigate the involvement of the p53 pathway in colistin-induced neurotoxicity in PC-12 cells. Specifically, cells were treated with colistin (125 μg/ml) in the absence and presence of a p53 inhibitor, pifithrin-α (PFT-α; 20 nM), for 12 h and 24 h, and the typical hallmarks of autophagy and apoptosis were examined by fluorescence/immunofluorescence microscopy and electron microscopy, real-time PCR, and Western blotting. The results indicate that colistin had a stimulatory effect on the expression levels of the target genes and proteins involved in autophagy and apoptosis, including LC3-II/I, p53, DRAM (damage-regulated autophagy modulator), PUMA (p53 upregulated modulator of apoptosis), Bax, p-AMPK (activated form of AMP-activated protein kinase), and caspase-3. In contrast, colistin appeared to have an inhibitory effect on the expression of p-mTOR (activated form of mammalian target of rapamycin), which is another target protein in autophagy. Importantly, analysis of the levels of p53 in the cells treated with colistin revealed an increase in nuclear p53 at 12 h and cytoplasmic p53 at 24 h. Pretreatment of colistin-treated cells with PFT-α inhibited autophagy and promoted colistin-induced apoptosis. This is the first study to demonstrate that colistin-induced autophagy and apoptosis are associated with the p53-mediated pathway.

scholarly journals Roles of pRB in the Regulation of Nucleosome and Chromatin Structures

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chiharu Uchida
Keyword(s):  
Target Genes ◽  
Chromosome Instability ◽  
Cancer Therapies ◽  
Induce Cell Cycle Arrest ◽  
Cellular Events ◽  
Cycle Arrest ◽  
Histone Modifiers ◽  
Physical Interactions ◽  
Functional Inactivation

Retinoblastoma protein (pRB) interacts with E2F and other protein factors to play a pivotal role in regulating the expression of target genes that induce cell cycle arrest, apoptosis, and differentiation. pRB controls the local promoter activity and has the ability to change the structure of nucleosomes and/or chromosomes via histone modification, epigenetic changes, chromatin remodeling, and chromosome organization. Functional inactivation of pRB perturbs these cellular events and causes dysregulated cell growth and chromosome instability, which are hallmarks of cancer cells. The role of pRB in regulation of nucleosome/chromatin structures has been shown to link to tumor suppression. This review focuses on the ability of pRB to control nucleosome/chromatin structures via physical interactions with histone modifiers and chromatin factors and describes cancer therapies based on targeting these protein factors.

The Histone Deacetylase Inhibitor LAQ824 Maintains Normal Hematopoietic Progenitor cells (HPC) Associated with Induction of Notch Target Genes and Does Not Eliminate Leukemic HPC in Vitro.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1352-1352
Author(s):  
Kerstin Schwarz ◽  
Oliver Ottmann ◽  
Annette Romanski ◽  
Anja Vogel ◽  
Jeffrey W. Scott ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Progenitor Cells ◽  
Gene Expression Analysis ◽  
Target Genes ◽  
Notch Pathway ◽  
Cycle Arrest ◽  
Cd34 Cells ◽  
20 Nm

Abstract Introduction: Histone deacetylase inhibitors (DACi) have shown promising antileukemic activity by overcoming the differentiation block and inducing apoptosis in AML blasts. Recent data demonstrating enhanced maintenance and functional capacity of normal, but also leukemic hematopoietic progenitor cells (HPC) by the selective class I DACi valproic acid (VPA) have raised concerns about VPA in AML therapy. As more potent pan-DACi have entered clinical trials, we analysed the impact of the hydroxamic acid LAQ824 on phenotype and function of normal and leukemic CD34+ HPC and studied LAQ824- induced gene expression in the most primitive CD34+CD38- population of normal HPC. Methods: Differentiation and proliferation of CD34+ cells of bone marrow of healthy donors and peripheral blood samples of newly diagnosed AML patients were evaluated after one week of culture in presence of SCF, FLT3 ligand, TPO, IL-3 +/− LAQ824. The effect of LAQ824 on gene expression profiles in normal CD34+CD38− cells was assessed in three independent cell samples following incubation with cytokines +/− LAQ824 for 48 hours using Affymetrix GeneChip Human Genome U133 Plus 2.0 and Gene Spring Software. Serial replating of murine Sca1+Lin- HPC was performed in the presence of SCF, G-CSF, GM-CSF, IL-3, IL-6 +/− LAQ824. Results: Treatment of murine Sca1+Lin- HPC with LAQ824 (10 nM) significantly augmented colony numbers (p<0.01; n=3), and supported colony growth after four cycles of replating whereas no colonies developed in its absence beyond the second plating indicating preservation of functionally active multipotent progenitor cells. LAQ824 (10–20 nM) mediated acetylation of histone H3 in human normal and leukemic HPC. In normal HPC, LAQ824 (0–20 nM) lead to a dose-dependent increase in the proportion of CD34+ cells (20% w/o LAQ824 vs. 36% with LAQ824 20nM, p=0.07) and a significant reduction of CD14+ monocytes (18% vs. 3%, p= 0.02; n=3). The total number of CD34+ cells remained stable up to 10 nM and decreased at 20 nM. Gene expression analysis showed, that LAQ824 (20 nM) lead to an at least 3-fold up-regulation of 221 genes in all three HPC samples tested including HDAC11 and the cell cycle inhibitor p21waf1/cip1 known to be induced by most DACi in HPC. We identified several members of the notch pathway such as mastermind-like protein 2 (MAML2, a component of the active notch transcriptional complex) and notch target genes including the transcription factors HES1, HEY1 and HOXA10 and confirmed increase of protein levels by Western blotting. Reduced gene expression of mini-chromosome-maintenance (MCM) protein family members was observed which - in addition to up-regulation of p21 - has previously been associated with notch-mediated cell cycle arrest. To compare the effect of LAQ824 (20 nM) with VPA (150 ng/ml) on leukemic HPC, cells were cultured for one week with or w/o DACi. Of note, LAQ824 resulted in a 0.8-fold reduction of CD34+ leukemic HPC, while VPA expanded this population 2.2-fold compared with cytokine-treated controls (p=0.03; n=12). CFU numbers growing from CD34+ leukemic HPC in presence of LAQ824 did not differ significantly from controls (n=9). Conclusion: LAQ824 seems to diminish, but not eliminate normal as well as leukemic HPC as determined by phenotypic and functional in vitro analyses. Our gene expression analysis suggested an association with coactivator and target genes of the notch pathway and cell cycle arrest-inducing genes. In contrast to VPA, LAQ824 does not seem to support growth of leukemic HPC which may contribute to its more potent antileukemic effect.

scholarly journals Inhibitory effect of c-Myc on p53-induced apoptosis in leukemia cells. Microarray analysis reveals defective induction of p53 target genes and upregulation of chaperone genes

Oncogene ◽  
2005 ◽  
Vol 24 (28) ◽  
pp. 4559-4571 ◽  
Author(s):  
Eva Ceballos ◽  
Maria J Muñoz-Alonso ◽  
Bernd Berwanger ◽  
Juan C Acosta ◽  
Rafael Hernández ◽  
...  
Keyword(s):  
Microarray Analysis ◽  
Target Genes ◽  
Inhibitory Effect ◽  
Leukemia Cells ◽  
Induced Apoptosis ◽  
P53 Target Genes

scholarly journals Isoliquiritigenin inhibits the proliferation, migration and metastasis of Hep3B cells via suppressing cyclin D1 and PI3K/AKT pathway

2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Yun Huang ◽  
Chen Liu ◽  
Wu-Cha Zeng ◽  
Guo-Yan Xu ◽  
Jian-Min Wu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Inhibitory Effect ◽  
Cycle Arrest ◽  
Novel Drugs ◽  
Epithelial Marker ◽  
Hep3b Cells ◽  
Induced Apoptosis

Abstract The overall survival rate of patients with hepatocellular carcinoma (HCC) has remained unchanged over the last several decades. Therefore, novel drugs and therapies are required for HCC treatment. Isoliquiritigenin (ISL), a natural flavonoid predominantly isolated from the traditional Chinese medicine Glycyrrhizae Radix (Licorice), has a high anticancer potential and broad application value in various cancers. Here, we aimed to investigate the anticancer role of ISL in the HCC cell line Hep3B. Functional analysis revealed that ISL inhibited the proliferation of Hep3B cells by causing G1/S cell cycle arrest in vitro. Meanwhile, the inhibitory effect of ISL on proliferation was also observed in vivo. Further analysis revealed that ISL could suppress the migration and metastasis of Hep3B cells in vitro and in vivo. Mechanistic analysis revealed that ISL inhibited cyclin D1 and up-regulated the proteins P21, P27 that negatively regulate the cell cycle. Furthermore, ISL induced apoptosis while inhibiting cell cycle transition. In addition, phosphatidylinositol 3′-kinase/protein kinase B (PI3K/AKT) signal pathway was suppressed by ISL treatment, and the epithelial marker E-cadherin was up-regulated when the mesenchymal markers Vimentin and N-cadherin were down-regulated. In brief, our findings suggest that ISL could be a promising agent for preventing HCC tumorigenesis and metastasis.

scholarly journals The pseudo-caspase FLIP(L) regulates cell fate following p53 activation

2020 ◽  
Vol 117 (30) ◽  
pp. 17808-17819 ◽  
Author(s):  
Andrea Lees ◽  
Alexander J. McIntyre ◽  
Nyree T. Crawford ◽  
Fiammetta Falcone ◽  
Christopher McCann ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cell Fate ◽  
Target Genes ◽  
Caspase 8 ◽  
Cycle Arrest ◽  
P53 Activation ◽  
Induced Apoptosis

p53 is the most frequently mutated, well-studied tumor-suppressor gene, yet the molecular basis of the switch from p53-induced cell-cycle arrest to apoptosis remains poorly understood. Using a combination of transcriptomics and functional genomics, we unexpectedly identified a nodal role for the caspase-8 paralog and only human pseudo-caspase, FLIP(L), in regulating this switch. Moreover, we identify FLIP(L) as a direct p53 transcriptional target gene that is rapidly up-regulated in response to Nutlin-3A, an MDM2 inhibitor that potently activates p53. Genetically or pharmacologically inhibiting expression of FLIP(L) using siRNA or entinostat (a clinically relevant class-I HDAC inhibitor) efficiently promoted apoptosis in colorectal cancer cells in response to Nutlin-3A, which otherwise predominantly induced cell-cycle arrest. Enhanced apoptosis was also observed when entinostat was combined with clinically relevant, p53-activating chemotherapy in vitro, and this translated into enhanced in vivo efficacy. Mechanistically, FLIP(L) inhibited p53-induced apoptosis by blocking activation of caspase-8 by the TRAIL-R2/DR5 death receptor; notably, this activation was not dependent on receptor engagement by its ligand, TRAIL. In the absence of caspase-8, another of its paralogs, caspase-10 (also transcriptionally up-regulated by p53), induced apoptosis in Nutlin-3A-treated, FLIP(L)-depleted cells, albeit to a lesser extent than in caspase-8-proficient cells. FLIP(L) depletion also modulated transcription of canonical p53 target genes, suppressing p53-induced expression of the cell-cycle regulator p21 and enhancing p53-induced up-regulation of proapoptotic PUMA. Thus, even in the absence of caspase-8/10, FLIP(L) silencing promoted p53-induced apoptosis by enhancing PUMA expression. Thus, we report unexpected, therapeutically relevant roles for FLIP(L) in determining cell fate following p53 activation.

scholarly journals Unique Triterpenoid of Jujube Root Protects Cisplatin-induced Damage in Kidney Epithelial LLC-PK1 Cells via Autophagy Regulation

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 677 ◽  
Author(s):  
Dahae Lee ◽  
Kyo Bin Kang ◽  
Hyun Woo Kim ◽  
Jung Sik Park ◽  
Gwi Seo Hwang ◽  
...  
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Protective Effects ◽  
Potential Mechanism ◽  
Protein Expressions ◽  
Ziziphus Jujuba ◽  
Induced Apoptosis ◽  
Kidney Impairment ◽  
Amp Activated Protein Kinase ◽  
Dependent Signaling Pathway

Chronic exposure to cisplatin is associated with irreversible kidney impairment. In this present study, we explored the protective effects of 3-dehydroxyceanothetric acid 2-methyl ester (3DC2ME) isolated from roots of jujube (Ziziphus jujuba, Rhamnaceae) against cisplatin-induced damage in vitro. In kidney epithelial LLC-PK1 cells, western blotting and staining with specific autophagy epifluorescent dye CytoID were used to determine the molecular pathways involving autophagy. Treatment with 3DC2ME reduced the increased Cyto-ID-stained autophagic vesicles and reversed the protein expressions of 5’ AMP-activated protein kinase subunit β-1 (AMPK)/mammalian target of rapamycin (mTOR)-dependent signaling pathway in cisplatin-induced cell death. Additionally, treatment with autophagy inhibitor 3-methyladenine (3-MA) and with or without 3DC2ME attenuated the cisplatin-induced apoptosis. Although further research is necessary to substantiate the effects, we evaluated the potential mechanism of action of 3DC2ME as an adjuvant for cancer patients.

scholarly journals Increased p53 Acetylation By SIRT1 Inhibition Is Required for Optimal Activation of p53 Activity and Significantly Enhances the Ability of HDM2 Inhibitors to Target CML LSC

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4521-4521
Author(s):  
Yann Pierre Kevin Duchartre ◽  
Ling Li ◽  
Tinisha McDonald ◽  
YinWei Ho ◽  
Yao-Te Hsieh ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Transcriptional Activity ◽  
Target Genes ◽  
Myelogenous Leukemia ◽  
Growth And Survival ◽  
Cycle Arrest ◽  
Cd34 Cells ◽  
Induced Apoptosis ◽  
P53 Target Genes

Abstract BCR-ABL tyrosine kinase inhibitors (TKI) are effective in inducing remissions and prolonging survival in chronic myelogenous leukemia (CML) patients, but do not eliminate leukemia stem cells (LSCs) that are responsible for establishment, maintenance and recurrence of the disease. We have shown that the NAD-dependent SIRT1 deacetylase is overexpressed in CML LSC (Li et al., Cancer Cell, 21:266, 2013). SIRT1 participates in the maintenance, growth and treatment resistance of CML LSC by deacetylation and inhibition of the p53 pathway that regulates cell cycle and apoptosis. Inhibition of SIRT1 using RNAi and the small molecule SIRT1 inhibitor Tenovin-6 (TV-6) inhibits growth and survival of CML LSC by itself and results in enhanced targeting of LSC in combination with TKI treatment. The effects of SIRT1 inhibition are related at least in part to enhanced acetylation of the p53 protein associated with enhanced p53 transcriptional activity. Here we examined the efficacy of an alternative strategy to activate p53, using inhibition of the p53 regulatory protein HDM2, in activating p53 transcriptional activity and inhibiting CML LSC growth and survival compared to SIRT1 inhibition. Nutlin-3 (Nut-3) is a small molecule HDM2 inhibitor that disrupts the p53-HDM2 interaction which has proceeded to clinical trials. Treatment of CML CP CD34+ cells with Nut-3 (1, 2, 5µM) increased expression of the p53 target genes p21 (associated with cell cycle arrest) and NOXA and PIG3 (associated with apoptosis), inhibited proliferation and induced apoptosis to a significantly lesser extent than TV-6 (1, 2 µM) (Nut 5 µM vs TV 2 µM ; p<0.0003) . However, Nutlin-3 enhanced p53 target gene expression and inhibited proliferation and survival of normal CD34+ cells to a similar extent as CML CD34+ cells. This was in contrast to TV-6 which although inhibiting proliferation of both CML and normal CD34+ cells, selectively induced apoptosis in CML compared to normal CD34+ cells. Treatment of CML CD34+ cells with the combination of Nut-3 (2, 5µM) and TV-6 (1µM) significantly increased the expression of p53 target genes (p21, PIG3, NOXA), and enhanced apoptosis of CML CD34+ cells compared to Nut-3 or TV-6 alone. 32D-BCR-ABL cells transduced with lentivirus vectors expressing p53 shRNA demonstrated significantly reduced apoptosis following treatment with the combination of Nut-3 and TV-6 compared to cells expressing control shRNA, indicating that the effects of this treatment are p53 dependent. Our results indicate that enhancement of p53 acetylation by SIRT1 inhibition is required for optimal activation of p53 transcriptional activity and induction of apoptosis in CML LSC. These results further support SIRT1 as a valid therapeutic target in CML, and suggest that addition of SIRT1 inhibitors may significantly enhance the ability of HDM2 inhibitors to eliminate CML LSC. Table 1 : Effects of Nutlin-3, Tenovin-6 or combination on the expression of apoptosis/cell cycle arrest related-genes, apoptosis and proliferation in cord blood and CML CD34+ cells. Figure 1 Figure 1. SEM values ; significance, compared to controls: ***p<0.001. ****p<0.0001. Key words : Chronic Myelogenous Leukemia (CML), hematopoietic stem cells, p53, SIRT1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Regulation of p53 by TopBP1: a Potential Mechanism for p53 Inactivation in Cancer

2009 ◽  
Vol 29 (10) ◽  
pp. 2673-2693 ◽  
Author(s):  
Kang Liu ◽  
Naresh Bellam ◽  
Hui-Yi Lin ◽  
Bing Wang ◽  
Cecil R. Stockard ◽  
...  
Keyword(s):  
Dna Damage ◽  
Target Genes ◽  
Tumor Grade ◽  
Binding Activity ◽  
Physiological Level ◽  
Cycle Arrest ◽  
P53 Target Gene ◽  
Induced Apoptosis ◽  
Cancer Tissues ◽  
P53 Inactivation

ABSTRACT Proper control of the G1/S checkpoint is essential for normal proliferation. The activity of p53 must be kept at a very low level under unstressed conditions to allow growth. Here we provide evidence supporting a crucial role for TopBP1 in actively repressing p53. Depletion of TopBP1 upregulates p53 target genes involved in cell cycle arrest and apoptosis and enhances DNA damage-induced apoptosis. The regulation is mediated by an interaction between the seventh and eighth BRCT domains of TopBP1 and the DNA-binding domain of p53, leading to inhibition of p53 promoter binding activity. Importantly, TopBP1 overexpression is found in 46 of 79 primary breast cancer tissues and is associated with high tumor grade and shorter patient survival time. Overexpression of TopBP1 to a level comparable to that seen in breast tumors leads to inhibition of p53 target gene expression and DNA damage-induced apoptosis and G1 arrest. Thus, a physiological level of TopBP1 is essential for normal G1/S transition, but a pathological level of TopBP1 in cancer may perturb p53 function and contribute to an aggressive tumor behavior.

scholarly journals Nobiletin Inhibits Non-Small-Cell Lung Cancer by Inactivating WNT/β-Catenin Signaling through Downregulating miR-15-5p

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sang Hyup Han ◽  
Jeong Hee Han ◽  
Wan Joo Chun ◽  
Sang Soo Lee ◽  
Hae Sung Kim ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Target Genes ◽  
Inhibitory Effect ◽  
Soft Agar ◽  
Small Cell ◽  
Small Cell Lung ◽  
Protein Levels ◽  
Induced Apoptosis

Background. Nobiletin is a natural compound with anticancer activity; however, the mechanism is not clear. Methods. The inhibitory effect of nobiletin on non-small-cell lung cancer (NSCLC) cells was examined using soft agar, Transwell, and apoptosis analyses. Cancer stemness was measured by sphere assay. Genes and miRNAs regulated by nobiletin were identified by whole-genome sequencing. Protein levels were detected by western blot and immunofluorescence assays. Results. Nobiletin significantly inhibited NSCLC cell colony formation and sphere formation and induced apoptosis. Nobiletin upregulated negative regulators of WNT/β-catenin signaling, including NKD1, AXIN2, and WIF1, while it inhibited the expression of β-catenin and its downstream genes, including c-Myc, c-Jun, and cyclin D1. Furthermore, we identified that GN inhibits miR-15-5p expression in NSCLC cells and that NKD1, AXIN2, and WIF1 are the target genes of miR-15-5p. Conclusions. Nobiletin has a strong inhibitory effect on NSCLC, and nobiletin plays an anticancer role by inhibiting miR-15-5p/β-catenin signaling in NSCLC.

Sign in / Sign up

Export Citation Format

Share Document