Four-agents-decoction extract inhibits endometriotic cell proliferation by arresting cell cycle at G2M phase

: Selected transcription factors have critical roles to play in organism survival by regulating the expression of genes that control the adaptations needed to handle stress conditions. The retinoblastoma (Rb) protein coupled with the E2F transcription factor family was demonstrated to have roles in controlling the cell cycle during freezing and associated environmental stresses (anoxia, dehydration). Rb phosphorylation or acetylation at different sites provide a mechanism for repressing cell proliferation that is under the control of E2F transcription factors in animals facing stresses that disrupt cellular energetics or cell volume controls. Other central regulators of the cell cycle including Cyclins, Cyclin dependent kinases (Cdks), and checkpoint proteins detect DNA damage or any improper replication, blocking further progression of cell cycle and interrupting cell proliferation. This review provides an insight into the molecular regulatory mechanisms of cell cycle control, focusing on Rb-E2F along with Cyclin-Cdk complexes typically involved in development and differentiation that need to be regulated in order to survive extreme cellular stress.

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Inhibition of Proliferation and Induction of Apoptosis by Thymoquinone via Modulation of TGF Family, p53, p21 and Bcl-2α in Leukemic Cells

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520617666170912133054 ◽

2018 ◽

Vol 18 (2) ◽

pp. 210-215 ◽

Cited By ~ 3

Author(s):

Mona Diab-Assaf ◽

Josiane Semaan ◽

Marwan El-Sabban ◽

Soad K. Al Jaouni ◽

Rania Azar ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

T Cell ◽

Flow Cytometric Analysis ◽

Leukemic Cells ◽

Cell Cycle Distribution ◽

Dependent Manner ◽

Apoptosis Induction ◽

Inhibition Of Proliferation ◽

Human T Cell

Introduction: Adult T-cell leukemia (ATL) is an aggressive form of malignancy caused by human T- cell lymphotropic virus 1 (HTLV-1). Currently, there is no effective treatment for ATL. Thymoquinone has been reported to have anti-cancer properties. Objective: The aim of this study is to investigatthe effects of TQ on proliferation, apoptosis induction and the underlying mechanism of action in both HTLV-1 positive (C91-PL and HuT-102) and HTLV-1 negative (CEM and Jurkat) malignant T-lymphocytes. Materials and Methods: Cells were incubated with different thymoquinone concentrations for 24h. Cell cytotoxicity was assayed using the CytoTox 96® Non-Radioactive Cytotoxicity Assay Kit. Cell proliferation was determined using CellTiter 96® Non-Radioactive Cell Proliferation. Cell cycle analysis was performed by staining with propidium iodide. Apoptosis was assessed using cell death ELISA kit. The effect of TQ on p53, p21, Bcl-2 protein expression was determined using Western blot analysis while TGF mRNA expression was determined by RT-PCR. Results: At non-cytotoxic concentrations of TQ, it resulted in the inhibition of proliferation in a dose dependent manner. Flow cytometric analysis revealed a shift in the cell cycle distribution to the PreG1 phase which is a marker of apoptosis. Also TQ increase DNA fragmentation. TQ mediated its anti-proliferative effect and apoptosis induction by an up-regulation of TGFβ1, p53 and p21 and a down-regulation of TGF-α and Bcl-2α. Conclusion: Thymoquinone presents antiproliferative and proapoptotic effects in ATL cells. For this reason, further research is required to investigate its possible application in the treatment of ATL.

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Follicle-Stimulating Hormone Inhibits Adenosine 5′-Monophosphate-Activated Protein Kinase Activation and Promotes Cell Proliferation of Primary Granulosa Cells in Culture through an Akt-Dependent Pathway

Endocrinology ◽

10.1210/en.2008-1032 ◽

2009 ◽

Vol 150 (2) ◽

pp. 929-935 ◽

Cited By ~ 55

Author(s):

Pradeep P. Kayampilly ◽

K. M. J. Menon

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Protein Kinase ◽

Mrna Expression ◽

Granulosa Cell ◽

Granulosa Cells ◽

Ampk Activation ◽

Cyclin D2 ◽

Cell Cycle Inhibitor ◽

Dependent Pathway

FSH, acting through multiple signaling pathways, regulates the proliferation and growth of granulosa cells, which are critical for ovulation. The present study investigated whether AMP-activated protein kinase (AMPK), which controls the energy balance of the cell, plays a role in FSH-mediated increase in granulosa cell proliferation. Cells isolated from immature rat ovaries were grown in serum-free, phenol red free DMEM-F12 and were treated with FSH (50 ng/ml) for 0, 5, and 15 min. Western blot analysis showed a significant reduction in AMPK activation as observed by a reduction of phosphorylation at thr 172 in response to FSH treatment at all time points tested. FSH also reduced AMPK phosphorylation in a dose-dependent manner with maximum inhibition at 100 ng/ml. The chemical activator of AMPK (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, 0.5 mm) increased the cell cycle inhibitor p27 kip expression significantly, whereas the AMPK inhibitor (compound C, 20 μm) and FSH reduced p27kip expression significantly compared with control. FSH treatment resulted in an increase in the phosphorylation of AMPK at ser 485/491 and a reduction in thr 172 phosphorylation. Inhibition of Akt phosphorylation using Akt inhibitor VIII reversed the inhibitory effect of FSH on thr 172 phosphorylation of AMPK, whereas ERK inhibitor U0126 had no effect. These results show that FSH, through an Akt-dependent pathway, phosphorylates AMPK at ser 481/495 and inhibits its activation by reducing thr 172 phosphorylation. AMPK activation by 5-amino-imidazole-4-carboxamide-1-β-d-ribofuranoside treatment resulted in a reduction of cell cycle regulatory protein cyclin D2 mRNA expression, whereas FSH increased the expression by 2-fold. These results suggest that FSH promotes granulosa cell proliferation by increasing cyclin D2 mRNA expression and by reducing p27 kip expression by inhibiting AMPK activation through an Akt-dependent pathway. FSH stimulates granulosa cell proliferation by reducing cell cycle inhibitor p27 kip through AMP kinase inhibition.

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BRD4 PROTAC degrader ARV-825 inhibits T-cell acute lymphoblastic leukemia by targeting 'Undruggable' Myc-pathway genes

Cancer Cell International ◽

10.1186/s12935-021-01908-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Shuiyan Wu ◽

You Jiang ◽

Yi Hong ◽

Xinran Chu ◽

Zimu Zhang ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Acute Lymphoblastic Leukemia ◽

Caspase 3 ◽

Lymphoblastic Leukemia ◽

Rna Seq ◽

Cell Acute Lymphoblastic Leukemia ◽

Bet Protein

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.

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STAU2 protein level is controlled by caspases and the CHK1 pathway and regulates cell cycle progression in the non-transformed hTERT-RPE1 cells

BMC Molecular and Cell Biology ◽

10.1186/s12860-021-00352-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Lionel Condé ◽

Yulemi Gonzalez Quesada ◽

Florence Bonnet-Magnaval ◽

Rémy Beaujois ◽

Luc DesGroseillers

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Cell Proliferation ◽

Dna Damage ◽

Steady State ◽

Posttranscriptional Regulation ◽

Cell Cycle Progression ◽

Rna Binding ◽

Regulation Of Gene Expression ◽

Cycle Progression

AbstractBackgroundStaufen2 (STAU2) is an RNA binding protein involved in the posttranscriptional regulation of gene expression. In neurons, STAU2 is required to maintain the balance between differentiation and proliferation of neural stem cells through asymmetric cell division. However, the importance of controlling STAU2 expression for cell cycle progression is not clear in non-neuronal dividing cells. We recently showed that STAU2 transcription is inhibited in response to DNA-damage due to E2F1 displacement from theSTAU2gene promoter. We now study the regulation of STAU2 steady-state levels in unstressed cells and its consequence for cell proliferation.ResultsCRISPR/Cas9-mediated and RNAi-dependent STAU2 depletion in the non-transformed hTERT-RPE1 cells both facilitate cell proliferation suggesting that STAU2 expression influences pathway(s) linked to cell cycle controls. Such effects are not observed in the CRISPR STAU2-KO cancer HCT116 cells nor in the STAU2-RNAi-depleted HeLa cells. Interestingly, a physiological decrease in the steady-state level of STAU2 is controlled by caspases. This effect of peptidases is counterbalanced by the activity of the CHK1 pathway suggesting that STAU2 partial degradation/stabilization fines tune cell cycle progression in unstressed cells. A large-scale proteomic analysis using STAU2/biotinylase fusion protein identifies known STAU2 interactors involved in RNA translation, localization, splicing, or decay confirming the role of STAU2 in the posttranscriptional regulation of gene expression. In addition, several proteins found in the nucleolus, including proteins of the ribosome biogenesis pathway and of the DNA damage response, are found in close proximity to STAU2. Strikingly, many of these proteins are linked to the kinase CHK1 pathway, reinforcing the link between STAU2 functions and the CHK1 pathway. Indeed, inhibition of the CHK1 pathway for 4 h dissociates STAU2 from proteins involved in translation and RNA metabolism.ConclusionsThese results indicate that STAU2 is involved in pathway(s) that control(s) cell proliferation, likely via mechanisms of posttranscriptional regulation, ribonucleoprotein complex assembly, genome integrity and/or checkpoint controls. The mechanism by which STAU2 regulates cell growth likely involves caspases and the kinase CHK1 pathway.

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Matrix degradation and cell proliferation are coupled to promote invasion and escape from an engineered human breast microtumor

Integrative Biology ◽

10.1093/intbio/zyaa026 ◽

2021 ◽

Vol 13 (1) ◽

pp. 17-29

Author(s):

Emann M Rabie ◽

Sherry X Zhang ◽

Andreas P Kourouklis ◽

A Nihan Kilinc ◽

Allison K Simi ◽

...

Keyword(s):

Breast Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Type I ◽

Matrix Degradation ◽

Human Breast ◽

Rate Of Invasion

Abstract Metastasis, the leading cause of mortality in cancer patients, depends upon the ability of cancer cells to invade into the extracellular matrix that surrounds the primary tumor and to escape into the vasculature. To investigate the features of the microenvironment that regulate invasion and escape, we generated solid microtumors of MDA-MB-231 human breast carcinoma cells within gels of type I collagen. The microtumors were formed at defined distances adjacent to an empty cavity, which served as an artificial vessel into which the constituent tumor cells could escape. To define the relative contributions of matrix degradation and cell proliferation on invasion and escape, we used pharmacological approaches to block the activity of matrix metalloproteinases (MMPs) or to arrest the cell cycle. We found that blocking MMP activity prevents both invasion and escape of the breast cancer cells. Surprisingly, blocking proliferation increases the rate of invasion but has no effect on that of escape. We found that arresting the cell cycle increases the expression of MMPs, consistent with the increased rate of invasion. To gain additional insight into the role of cell proliferation in the invasion process, we generated microtumors from cells that express the fluorescent ubiquitination-based cell cycle indicator. We found that the cells that initiate invasions are preferentially quiescent, whereas cell proliferation is associated with the extension of invasions. These data suggest that matrix degradation and cell proliferation are coupled during the invasion and escape of human breast cancer cells and highlight the critical role of matrix proteolysis in governing tumor phenotype.

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