scholarly journals Interplay between p300 and HDAC1 regulate acetylation and stability of Api5 to regulate cell proliferation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Virender Kumar Sharma ◽  
Mayurika Lahiri
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Histone Acetyltransferase ◽  
Nuclear Protein ◽  
Essential Factor ◽  
Post Translational Modification ◽  
Dynamic Switch

AbstractApi5, is a known anti-apoptotic and nuclear protein that is responsible for inhibiting cell death in serum-starved conditions. The only known post-translational modification of Api5 is acetylation at lysine 251 (K251). K251 acetylation of Api5 is responsible for maintaining its stability while the de-acetylated form of Api5 is unstable. This study aimed to find out the enzymes regulating acetylation and deacetylation of Api5 and the effect of acetylation on its function. Our studies suggest that acetylation of Api5 at lysine 251 is mediated by p300 histone acetyltransferase while de-acetylation is carried out by HDAC1. Inhibition of acetylation by p300 leads to a reduction in Api5 levels while inhibition of deacetylation by HDAC1 results in increased levels of Api5. This dynamic switch between acetylation and deacetylation regulates the localisation of Api5 in the cell. This study also demonstrates that the regulation of acetylation and deacetylation of Api5 is an essential factor for the progression of the cell cycle.

scholarly journals Interplay between p300 and HDAC1 regulate acetylation and stability of Api5 to regulate cell proliferation

2020 ◽  
Author(s):  
Virender Kumar Sharma ◽  
Mayurika Lahiri
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Histone Acetyltransferase ◽  
Nuclear Protein ◽  
Essential Factor ◽  
Post Translational Modification ◽  
Dynamic Switch

AbstractApi5, is a known anti-apoptotic and nuclear protein that is responsible for inhibiting cell death in serum-starved conditions. The only known post-translational modification of Api5 is acetylation at lysine 251 (K251). K251 acetylation of Api5 is responsible for maintaining its stability while de-acetylated form of Api5 is unstable. This study aimed to find out the enzymes regulating acetylation and deacetylation of Api5 and the effect of acetylation on its function. Our studies suggest that acetylation of Api5 at lysine 251 is mediated by p300 histone acetyltransferase while de-acetylation is carried out by HDAC1. Inhibition of acetylation by p300 leads to reduction in Api5 levels while inhibition of deacetylation by HDAC1 results in increased levels of Api5. This dynamic switch between acetylation and deacetylation regulate the localization of Api5 in the cell. This study also demonstrates that the regulation of acetylation and deacetylation of Api5 is an essential factor for the progression of the cell cycle.

scholarly journals Growth-factor-dependent phosphorylation of Bim in mitosis

2005 ◽  
Vol 388 (1) ◽  
pp. 185-194 ◽  
Author(s):  
Mário GRÃOS ◽  
Alexandra D. ALMEIDA ◽  
Sukalyan CHATTERJEE
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Growth Factor ◽  
Cell Fate ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Post Translational Modification ◽  
Proliferating Cells ◽  
Growth Factor Signalling ◽  
Induced Apoptosis

The regulation of survival and cell death is a key determinant of cell fate. Recent evidence shows that survival and death machineries are regulated along the cell cycle. In the present paper, we show that BimEL [a BH3 (Bcl-2 homology 3)-only member of the Bcl-2 family of proteins; Bim is Bcl-2-interacting mediator of cell death; EL is the extra-long form] is phosphorylated in mitosis. This post-translational modification is dependent on MEK (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase) and growth factor signalling. Interestingly, FGF (fibroblast growth factor) signalling seems to play an essential role in this process, since, in the presence of serum, inhibition of FGF receptors abrogated phosphorylation of Bim in mitosis. Moreover, we have shown bFGF (basic FGF) to be sufficient to induce phosphorylation of Bim in serum-free conditions in any phase of the cell cycle, and also to significantly rescue cells from serum-deprivation-induced apoptosis. Our results show that, in mitosis, Bim is phosphorylated downstream of growth factor signalling in a MEK-dependent manner, with FGF signalling playing an important role. We suggest that phosphorylation of Bim is a decisive step for the survival of proliferating cells.

PCNA and total nuclear protein content as markers of cell proliferation in pea tissue

1992 ◽  
Vol 102 (1) ◽  
pp. 71-78 ◽  
Author(s):  
SANDRA CITTERIO ◽  
SERGIO SGORBATI ◽  
MARISA LEVI ◽  
BRUNO MARIA COLOMBO ◽  
ELIO SPARVOLI
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Content ◽  
Time Course ◽  
Nuclear Protein ◽  
Flow Cytometric Analysis ◽  
Nuclear Antigen ◽  
Cycle Phase ◽  
Proliferating Cells ◽  
Embryo Cells

The identification of cell proliferation markers has been shown to be a useful tool with which to study basic mechanisms of cell cycle progression. The use of immunofluorescence techniques revealed the presence of the proliferating cell nuclear antigen (PCNA) in pea tissue, where we observed a high PCNA expression in proliferating cells of the root meristem compared to noncycling cells of the differentiated leaf. The presence of PCNA was monitored also during the time-course of seed germination, before, during and after the cell cycle resumption of the embryo cells. PCNA is present in embryo cells not only during and after resumption of the cell cycle but also before, when cells have not yet begun replicating their genome. A bivariate flow cytometric analysis of DNA and nuclear protein content was used to localize precisely the cells of the examined pea tissues in different cell cycle phase subcompartments. A high correlation was found between the degree of cell proliferation and the protein content of G1 nuclei, on the one hand, and the percentage of PCNA positive cells on the other.

scholarly journals SIRT7 Deacetylates STRAP to Regulate p53 Activity and Stability

2020 ◽  
Vol 21 (11) ◽  
pp. 4122 ◽  
Author(s):  
Miao Yu ◽  
Xiaoyan Shi ◽  
Mengmeng Ren ◽  
Lu Liu ◽  
Hao Qi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Cell Cycle Arrest ◽  
Creb Binding Protein ◽  
Serine Threonine Kinase ◽  
Receptor Associated Protein ◽  
Threonine Kinase ◽  
P53 Signaling ◽  
Cycle Arrest

Serine-threonine kinase receptor-associated protein (STRAP) functions as a regulator of both TGF-β and p53 signaling that participates in the regulation of cell proliferation and cell death in response to various stresses. Here, we demonstrate that STRAP acetylation plays an important role in p53-mediated cell cycle arrest and apoptosis. STRAP is acetylated at lysines 147, 148, and 156 by the acetyltransferases CREB-binding protein (CBP) and that the acetylation is reversed by the deacetylase sirtuin7 (SIRT7). Hypo- or hyperacetylation mutations of STRAP at lysines 147, 148, and 156 (3KR or 3KQ) influence its activation and stabilization of p53. Moreover, following 5-fluorouracil (5-FU) treatment, STRAP is mobilized from the cytoplasm to the nucleus and promotes STRAP acetylation. Our finding on the regulation of STRAP links p53 with SIRT7 influencing p53 activity and stability.

Combined Inhibition of Janus and Aurora Kinases by the Novel Small Molecule Inhibitor AZD1480 Induces Cell Death and Downregulates PD-L1 and PD-L2 Expression In Hodgkin Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2848-2848
Author(s):  
Enrico Derenzini ◽  
Daniela Buglio ◽  
Hiroshi Katayama ◽  
Yuan Ji ◽  
Subrata Sen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Cell Lines ◽  
Immune Escape ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Aurora Kinases ◽  
Mitotic Block ◽  
Dose Dependent

Abstract Abstract 2848 Hodgkin Lymphoma (HL) cell proliferation and survival is sustained by a complex network of cytokine signaling, involving the Hodgkin and Reed-Sternberg cells and tumor microenvironment. Following cytokine stimulation, JAK-STAT activation promotes the transcription of target genes involved in proliferation, survival, and immune escape. Programmed Death-ligands 1 and 2 (PD-L1 and PD-L2) and the Th2 chemokine TARC are immune-modulators involved in immune evasion, respectively through inhibition of effector T cell function (PD-L1, PD-L2) and attraction and homing of Th2 cells (TARC). Aurora kinases are frequently overexpressed in human cancers and play essential functions in chromosome alignment and cytokinesis. The role of Aurora kinases in Hodgkin lymphomagenesis is not defined yet. In this study we report the activity profile of the JAK2 inhibitor AZD1480 in HL cell lines (HD-LM2, L-428, KM-H2, L-540). To assess the effect of AZD1480 on cell proliferation, cells were incubated with increasing concentrations of AZD1480 (from 0.1 to 10 μM) for 24, 48 and 72 hours (hrs). A significant growth inhibition was evident after 72 hrs of incubation, specially using the high doses of AZD1480 (5μM). The L-540 cell line showed the highest sensitivity, with a decrease in cell viability close to 50% following incubation with AZD1480 1μM. Inhibition of STAT3, STAT5 and STAT6 phosphorylation in the L-540, L-428 and HD-LM2 cell lines was observed with concentrations equal to 0.1 μM or higher. Using Annexin V- propidium iodide staining, we found that AZD1480 induced cell death by apoptosis in a dose dependent manner after 72 hrs of incubation when a high concentration (5μM) of the drug was used. Lower concentrations of AZD1480 (1μM) promoted a statistically significant increase in cell death only in the L-540 and to a lesser extent in the L-428 cell line. Consistent with this data, also caspase 9, 3 and PARP cleavage was observed in all the cell lines exposed to AZD1480 5 μM. AZD1480 5μM promoted a marked increase in the G2/M fraction in all the cell lines as soon as 24 hrs after incubation, especially in the HD-LM2 and L-428 cell lines. Treatment with lower doses (1μM) did not affect significantly the cell cycle. Since AZD1480 was also reported to inhibit Aurora A kinase at nanomolar concentrations in enzymatic assays, we assessed if the significant increase in the G2/M fraction was related to the inhibition of the Aurora A kinase. We evaluated the levels of autophosphorylation on Thr-288 by western blotting. Cells were pretreated with Nocodazole 400 ng/ml for 18 hrs in order to achieve a mitotic block, and then exposed to AZD1480 (1-5μM) and/or the proteasome inhibitor MG132 (20μM) (in order to prevent the potential overriding of the Nocodazole induced mitotic block), for 3 hours. A dose-dependent inhibition of Aurora A was detected in all the cell lines, with a complete abrogation when higher doses of AZD1480 were used (5μM). These findings are consistent with the analysis of the cell cycle fractions, showing dose-dependent changes of the cell cycle at 24 hrs following incubation with AZD1480. AZD1480 also decreased the secretion of key cytokines involved autocrine and paracrine survival loops and immune escape. Following incubation with AZD1480 1μM for 72 hrs cell culture supernatants were analyzed by ELISA: decreased levels of IL-6, IL-13, TARC, and IL-21 were observed in HD-LM2, L-428 and L-540 cells. Moreover we assessed the expression of PD-L1 and PD-L2 by flow cytometry and observed significant downregulation in the PD-L1/PD-L2 overexpressing cell lines (L-540 and HD-LM2). These data suggest that AZD1480 has a pleiotropic mechanism of action in HL by targeting the JAK-STAT and the Aurora kinase pathway, and by altering the pattern of cytokine and chemokine secretion and the expression of factors involved in immune escape. Our study provides the rationale for further clinical investigation of AZD1480 in HL. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Internalization of Titanium Dioxide Nanoparticles Is Cytotoxic for H9c2 Rat Cardiomyoblasts

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1955 ◽  
Author(s):  
Elizabeth Huerta-García ◽  
Iván Zepeda-Quiroz ◽  
Helen Sánchez-Barrera ◽  
Zaira Colín-Val ◽  
Ernesto Alfaro-Moreno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Membrane Integrity ◽  
The Body ◽  
Potential Health ◽  
Tio2 Nps

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in industry and daily life. TiO2 NPs can penetrate into the body, translocate from the lungs into the circulation and come into contact with cardiac cells. In this work, we evaluated the toxicity of TiO2 NPs on H9c2 rat cardiomyoblasts. Internalization of TiO2 NPs and their effect on cell proliferation, viability, oxidative stress and cell death were assessed, as well as cell cycle alterations. Cellular uptake of TiO2 NPs reduced metabolic activity and cell proliferation and increased oxidative stress by 19-fold measured as H2DCFDA oxidation. TiO2 NPs disrupted the plasmatic membrane integrity and decreased the mitochondrial membrane potential. These cytotoxic effects were related with changes in the distribution of cell cycle phases resulting in necrotic death and autophagy. These findings suggest that TiO2 NPs exposure represents a potential health risk, particularly in the development of cardiovascular diseases via oxidative stress and cell death.

scholarly journals Inhibitory effect and mechanism of action (MOA) of hirsutine on the proliferation of T-cell leukemia Jurkat clone E6-1 cells

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10692
Author(s):  
Jie Meng ◽  
Rui Su ◽  
Luping Wang ◽  
Bo Yuan ◽  
Ling Li
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Cell Proliferation ◽  
Cell Death ◽  
T Cell ◽  
Mechanism Of Action ◽  
Mrna Levels ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Antitumor Effects

Background The bark of Uncaria rhynchophylla has been traditionally used to treat convulsion, bleeding, hypertension, auto-immune conditions, cancer, and other diseases. The main focus of this research is done for the purpose of exploring the antitumor activity and mechanism of action (MOA) for hirsutine isolated from U. rhynchophylla. Methods Jurkat clone E6-1 cells were treated using 10, 25 and 50 μM for 48 h. Inhibition of cell proliferation due to hirsutine treatment was evaluated by CCK8 assay. Flow cytometry was applied to ascertain Jurkat cell cycle progression and apoptosis after treatment with 10, 25 and 50 μM hirsutine for 48 h. The expression and level of the apoptosis-related genes and proteins was analyzed by Real-time Quantitative polymerase chain reaction (qPCR) and Western blotting method, respectively. Results CCK8 analyses revealed that hirsutine could significantly inhibit the proliferation of Jurkat clone E6-1 cells, in a concentration and time-dependent fashion. Flow cytometry assays revealed that hirsutine could drive apoptotic death and G0/G1 phase arrest in Jurkat cells. Apoptotic cells frequencies were 4.99 ± 0.51%, 13.69 ± 2.00% and 40.21 ± 15.19%, and respective cell cycle arrest in G0/G1 accounted for 34.85 ± 1.81%, 42.83 ± 0.70% and 49.12 ± 4.07%. Simultaneously, compared with the control group, Western blot assays indicated that the up-regulation of pro-apoptotic Bax, cleaved-caspase3, cleaved-caspase9 and Cyto c proteins, as well as the down-regulation of Bcl-2 protein which guards against cell death, might be correlated with cell death induction and inhibition of cell proliferation. QPCR analyses indicated that hirsutine could diminish BCL2 expression and, at the same time, improve Bax, caspase-3 and caspase-9 mRNA levels, thus reiterating a putative correlation of hirsutine treatment in vitro with apoptosis induction and inhibition of cell proliferation (p-value < 0.05). Excessive hirsutine damages the ultrastructure in mitochondria, leading to the release of Cyt c from the mitochondria to cytoplasm in Jurkat clone E6-1 cells, thereby inducing the activated caspase cascade apoptosis process through a mitochondria-mediated pathway. Conclusion An important bioactive constituent—hirsutine—appears to have antitumor effects in human T-cell leukemia, thus enlightening the use of phytomedicines as a novel source for tumor therapy. It is speculated that hirsutine may induce apoptosis of Jurkat Clone E6-1 cells through the mitochondrial apoptotic pathway.

scholarly journals Analysis of the use of photosensitization in human glioblastoma multiforme to induce cell death

2019 ◽  
Vol 98 (Suppl) ◽  
pp. 25-25
Author(s):  
Mario Minor Murakami Junior ◽  
Yollanda E. Moreira Franco ◽  
Maurício Da Silva Baptista ◽  
Suely Kazue Nagahashi Marie
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Methylene Blue ◽  
Cell Proliferation ◽  
Cell Death ◽  
Acridine Orange ◽  
Light Irradiation ◽  
Rt Pcr ◽  
Low Concentration ◽  
The Impact

Introduction: The most frequent primary tumor of the central nervous system is the malignant glioma, being the glioblastoma (GBM), grade IV astrocytoma, the most aggressive and lethal glioma. Malignant astrocytomas are responsive for therapy targeting autophagy as temozolomide, the standard adjuvant treatment which induces autophagic cell death. Autophagy is a homeostatic intracellular process that eliminate old proteins and recycle cellular components. Mitophagy is a subtype of autophagy that regulates the removal of damaged, dysfunctional or redundant mitochondria. Parallel damage against lysosomes and mitochondria membranes using photosensitized oxidations and strong redox stress leads to activation of mitophagy and malfunction of autophagy. This mechanism of photosensitization, ultimately, causes cell death. Challenging cells with a low concentration of a photosensitizer as 1,9-dimethyl methylene blue (DMMB) combined with light- irradiation of 12 joules/cm2 have induced mitochondrial damage with activation of mitophagy and concomitant lysosome damage, in skin-derived cell lines. This experimental design was applied to U87MG GBM cells to verify if tumor cell death may be obtained with combined mitochondrial and lysosomal damages to open new therapeutic strategies for GBM and to better understand the mechanisms of mitophagy.Objectives: Our primary objective is to analyze the impact of challenging GBM cells with a low concentration of 1,9-dimethyl methylene blue (DMMB) with combined light- irradiation of 12 joules/cm2.Methodology: U87MG a human GBM cell line was used. The photodamage was performed using DMMB photosensitized by a LED with maximum emission wavelength at 630 nm providing 12 J/cm2. Cell proliferation and viability assays were performed using MTT to assess whether there was proliferation inhibition and/or alteration of cell viability after photosensitization. Quantification of cells in different stages of apoptosis, and in the various phases of the cell cycle were analyzed using flow cytometry after photosensitization. Acridine orange assay was used to assess lysosome damage. RT-PCR and Western Blotting were performed to evaluate the expression levels of the main autophagy and mitophagy genes and proteins.Partial Results: Cell proliferation and viability assays demonstrated that the concentration of DMMB to cause 50% inhibition of biological activity of cells (IC50) was 10 nM after 48h. The apoptosis and cell cycle experiments were performed in this concentration. Increase in apoptosis was observed after 24hs of photosensitization. Currently, the cell cycle flow cytometry assay has been performed, followed by the quantification of lysosomes damage by Acridine Orange assay. The genes and proteins involved in the mechanisms of autophagy and mitophagy will be determined by expression analysis through RT-PCR and Western blot assays.Discussion and Conclusion: For a future perspective, if this prove of concept is achieved, i.e. death of tumor cells by the combined approach of photosensitizer with irradiation, a new therapeutic strategy of light-activated drugs may be offered to cancer patients.

scholarly journals Distinct Signaling Pathways Mediate Stimulation of Cell Cycle Progression and Prevention of Apoptotic Cell Death by Estrogen in Rat Pituitary Tumor PR1 Cells

2003 ◽  
Vol 14 (12) ◽  
pp. 5051-5059 ◽  
Author(s):  
Simona Caporali ◽  
Manami Imai ◽  
Lucia Altucci ◽  
Massimo Cancemi ◽  
Silvana Caristi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Dna Synthesis ◽  
Cell Survival ◽  
Pituitary Tumor ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Rat Pituitary ◽  
Stimulation Of

Estrogens control cell growth and viability in target cells via an interplay of genomic and extragenomic pathways not yet elucidated. Here, we show evidence that cell proliferation and survival are differentially regulated by estrogen in rat pituitary tumor PR1 cells. Pico- to femtomolar concentrations of 17β-estradiol (E2) are sufficient to foster PR1 cell proliferation, whereas nanomolar concentrations of the same are needed to prevent cell death that occurs at a high rate in these cells in the absence of hormone. Activation of endogenous (PRL) or transfected estrogen-responsive genes occurs at the same, higher concentrations of E2 required to promote cell survival, whereas stimulation of cyclin D3 expression and DNA synthesis occur at lower E2 concentrations. Similarly, the pure antiestrogen ICI 182,780 inhibits estrogen response element-dependent trans-activation and cell death more effectively than cyclin-cdk activity, G1-S transition, or DNA synthesis rate. In antiestrogen-treated and/or estrogen-deprived cells, death is due predominantly to apoptosis. Estrogen-induced cell survival, but not E2-dependent cell cycle progression, can be prevented by an inhibitor of c-Src kinase or by blockade of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling pathway. These data indicate the coexistence of two distinguishable estrogen signaling pathways in PR1 cells, characterized by different functions and sensitivity to hormones and antihormones.

scholarly journals MOF Regulates TNK2 Transcription Expression to Promote Cell Proliferation in Thyroid Cancer

2020 ◽  
Vol 11 ◽  
Author(s):  
Danyang Li ◽  
Yang Yang ◽  
Bo Chen ◽  
Xinghong Guo ◽  
Shuang Gao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Thyroid Cancer ◽  
Cell Lines ◽  
Histone Acetyltransferase ◽  
Expression Level ◽  
Cancer Tissue ◽  
Histone H4 ◽  
Tissue Samples ◽  
Promote Cell Proliferation

MOF is a well-known histone acetyltransferase to catalyze acetylation of histone H4 lysine 16 (K16), and it is relevant to diverse biological processes, such as gene transcription, cell cycle, early embryonic development and tumorigenesis. Here, we identify MOF as an oncogene in most thyroid cancer. It is found that expression level of MOF was significantly upregulated in most thyroid cancer tissue samples and cell lines. MOF-deficient in both BHP-10-3 and TT2609 cell lines inhibited cell proliferation by blocking the cell cycle in G1 phase and enhanced cell apoptosis. Mechanistically, MOF bound the TNK2 promoter to activate TNK2 transcription. Furthermore, the expression level of TNK2 was decreased with the histone acetyltransferase inhibitor. Besides, MOF promoted proliferation of thyroid cancer cells through increased phosphorylation of AKT, thus activating the PI3K/AKT pathway. Ultimately, our findings indicated that MOF played an oncogene role in development and progression of thyroid cancer and may be a potential novel target for the treatment of thyroid cancer.

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