scholarly journals Analysis of Cell Cycle and Replication of Mouse Macrophages afterIn VivoandIn VitroCryptococcus neoformans Infection Using Laser Scanning Cytometry

2012 ◽  
Vol 80 (4) ◽  
pp. 1467-1478 ◽  
Author(s):  
Carolina Coelho ◽  
Lydia Tesfa ◽  
Jinghang Zhang ◽  
Johanna Rivera ◽  
Teresa Gonçalves ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cytotoxic Effect ◽  
Laser Scanning ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Content Type ◽  
Cycle Arrest ◽  
Laser Scanning Cytometry

ABSTRACTWe investigated the outcome of the interaction ofCryptococcus neoformanswith murine macrophages using laser scanning cytometry (LSC). Previous results in our lab had shown that phagocytosis ofC. neoformanspromoted cell cycle progression. LSC allowed us to simultaneously measure the phagocytic index, macrophage DNA content, and 5-ethynyl-2′-deoxyuridine (EdU) incorporation such that it was possible to study host cell division as a function of phagocytosis. LSC proved to be a robust, reliable, and high-throughput method for quantifying phagocytosis. Phagocytosis ofC. neoformanspromoted cell cycle progression, but infected macrophages were significantly less likely to complete mitosis. Hence, we report a new cytotoxic effect associated with intracellularC. neoformansresidence that manifested itself in impaired cell cycle completion as a consequence of a block in the G2/M stage of the mitotic cell cycle. Cell cycle arrest was not due to increased cell membrane permeability or DNA damage. We investigated alveolar macrophage replicationin vivoand demonstrated that these cells are capable of low levels of cell division in the presence or absence ofC. neoformansinfection. In summary, we simultaneously studied phagocytosis, the cell cycle state of the host cell and pathogen-mediated cytotoxicity, and our results demonstrate a new cytotoxic effect ofC. neoformansinfection on murine macrophages: fungus-induced cell cycle arrest. Finally, we provide evidence for alveolar macrophage proliferationin vivo.

scholarly journals Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Peter E. Burby ◽  
Lyle A. Simmons
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Genome Instability ◽  
Sos Response ◽  
Bacterial Cells ◽  
Cycle Progression ◽  
Content Type

ABSTRACT All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.

scholarly journals Roquin1 Suppresses Breast Cancer Growth by Inducing Cell Cycle Arrest via Selectively Destabilizing Cell Cycle–Promoting Gene mRNAs

2020 ◽  
Author(s):  
Wenbao Lu ◽  
Meicen Zhou ◽  
Bing Wang ◽  
Xueting Liu ◽  
Bingwei Li
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Breast Cancer Cell ◽  
Breast Tumor ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Cycle Arrest

Abstract Background: Dysregulation of cell cycle progression is one of the common features of human cancer cells, however, its mechanism remains unclear. This study aims to clarify the role and the underlying mechanisms of Roquin1 in cell cycle arrest induction in breast cancer.Methods: Public cancer databases were analyzed to identify the expression pattern of Roquin1 in human breast cancers and the significant association with patient survival. Quantitative real-time PCR and western blots were performed to detect the expression of Roquin1 in breast cancer samples and cell lines. Cell counting, MTT assay, flow cytometry, and in vivo study were conducted to investigate the effects of Roquin1 on cell proliferation, cell cycle progression and tumor progression. RNA-sequencing was applied to identify the differential genes and pathways regulated by Roquin1. RNA immunoprecipitation assay, luciferase reporter assay, mRNA half-life detection, RNA affinity binding assay, and RIP-ChIP were used to explore the molecular mechanisms of Roquin1.Results: We showed that Roquin1 expression in breast cancer tissues and cell lines was inhibited, and the reduction in Roquin1 expression was associated with poor overall survival and relapse free survival of patients with breast cancer. Roquin1 overexpression inhibited breast cancer cell proliferation and induced G1/S cell cycle arrest without causing significant apoptosis. In contrast, knockdown of Roquin1 promoted breast cancer cell growth and cycle progression. Moreover, in vivo induction of Roquin1 by adenovirus significantly suppressed breast tumor growth and metastasis. Mechanistically, Roquin1 selectively destabilizing cell cycle–promoting genes, including Cyclin D1, Cyclin E1, cyclin dependent kinase 6 (CDK6) and minichromosome maintenance 2 (MCM2) through targeting the stem–loop structure in the 3’untranslated region (3’UTR) of mRNAs via its ROQ domain, leading to the downregulation of cell cycle–promoting mRNAs.Conclusions: Our findings demonstrated that Roquin1 was a novel breast tumor suppressor and could induce G1/S cell cycle arrest by selectively downregulating the expression of cell cycle–promoting genes, which might as a potential molecular target for breast cancer treatment.

scholarly journals Roquin1 inhibits the proliferation of breast cancer cells by inducing G1/S cell cycle arrest via selectively destabilizing the mRNAs of cell cycle–promoting genes

2020 ◽  
Author(s):  
Wenbao Lu ◽  
Meicen Zhou ◽  
Bing Wang ◽  
Xueting Liu ◽  
Bingwei Li
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Breast Tumor ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Cycle Arrest

Abstract Background: Dysregulation of cell cycle progression is a common feature of human cancer cells; however, its mechanism remains unclear. This study aims to clarify the role and the underlying mechanisms of Roquin1 in cell cycle arrest in breast cancer.Methods: Public cancer databases were analyzed to identify the expression pattern of Roquin1 in human breast cancers and its association with patient survival. Quantitative real-time PCR and Western blots were performed to detect the expression of Roquin1 in breast cancer samples and cell lines. Cell counting, MTT assays, flow cytometry, and in vivo analyses were conducted to investigate the effects of Roquin1 on cell proliferation, cell cycle progression and tumor progression. RNA sequencing was applied to identify the differentially expressed genes regulated by Roquin1. RNA immunoprecipitation assay, luciferase reporter assay, mRNA half-life detection, RNA affinity binding assay, and RIP-ChIP were used to explore the molecular mechanisms of Roquin1.Results: We showed that Roquin1 expression in breast cancer tissues and cell lines was inhibited, and the reduction in Roquin1 expression was associated with poor overall survival and relapse-free survival of patients with breast cancer. Roquin1 overexpression inhibited cell proliferation and induced G1/S cell cycle arrest without causing significant apoptosis. In contrast, knockdown of Roquin1 promoted cell growth and cycle progression. Moreover, in vivo induction of Roquin1 by adenovirus significantly suppressed breast tumor growth and metastasis. Mechanistically, Roquin1 selectively destabilizes cell cycle–promoting genes, including Cyclin D1, Cyclin E1, cyclin dependent kinase 6 (CDK6) and minichromosome maintenance 2 (MCM2), by targeting the stem–loop structure in the 3' untranslated region (3'UTR) of mRNAs via its ROQ domain, leading to the downregulation of cell cycle–promoting mRNAs.Conclusions: Our findings demonstrated that Roquin1 is a novel breast tumor suppressor and could induce G1/S cell cycle arrest by selectively downregulating the expression of cell cycle–promoting genes, which might be a potential molecular target for breast cancer treatment.

scholarly journals Roquin1 inhibits the proliferation of breast cancer cells by inducing G1/S cell cycle arrest via selectively destabilizing the mRNAs of cell cycle–promoting genes

2020 ◽  
Author(s):  
Wenbao Lu ◽  
Meicen Zhou ◽  
Bing Wang ◽  
Xueting Liu ◽  
Bingwei Li
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Breast Tumor ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Cycle Arrest

Abstract Background: Dysregulation of cell cycle progression is one of the common features of human cancer cells, however, its mechanism remains unclear. This study aims to clarify the role and the underlying mechanisms of Roquin1 in cell cycle arrest induction in breast cancer. Methods: Public cancer databases were analyzed to identify the expression pattern of Roquin1 in human breast cancers and the significant association with patient survival. Quantitative real-time PCR and western blots were performed to detect the expression of Roquin1 in breast cancer samples and cell lines. Cell counting, MTT assay, flow cytometry, and in vivo study were conducted to investigate the effects of Roquin1 on cell proliferation, cell cycle progression and tumor progression. RNA-sequencing was applied to identify the differential genes and pathways regulated by Roquin1. RNA immunoprecipitation assay, luciferase reporter assay, mRNA half-life detection, RNA affinity binding assay, and RIP-ChIP were used to explore the molecular mechanisms of Roquin1. Results: We showed that Roquin1 expression in breast cancer tissues and cell lines was inhibited, and the reduction in Roquin1 expression was associated with poor overall survival and relapse free survival of patients with breast cancer. Roquin1 overexpression inhibited breast cancer cell proliferation and induced G1/S cell cycle arrest without causing significant apoptosis. In contrast, knockdown of Roquin1 promoted breast cancer cell growth and cycle progression. Moreover, in vivo induction of Roquin1 by adenovirus significantly suppressed breast tumor growth and metastasis. Mechanistically, Roquin1 selectively destabilizing cell cycle–promoting genes, including Cyclin D1, Cyclin E1, cyclin dependent kinase 6 (CDK6) and minichromosome maintenance 2 (MCM2) through targeting the stem–loop structure in the 3’untranslated region (3’UTR) of mRNAs via its ROQ domain, leading to the downregulation of cell cycle–promoting mRNAs. Conclusions: Our findings demonstrated that Roquin1 was a novel breast tumor suppressor and could induce G1/S cell cycle arrest by selectively downregulating the expression of cell cycle–promoting genes, which might as a potential molecular target for breast cancer treatment.

scholarly journals Cell Cycle Arrest and Autophagy Induced by Compound Kushen Injection in sw620 and sw480 Colorectal Cancer Cells with p53 Mutation

2019 ◽  
Author(s):  
Jie Sun ◽  
Di Wang ◽  
Yu Zhang ◽  
Qing Mu ◽  
Mei Li ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Cancer Cells ◽  
Cell Cycle Progression ◽  
Mutant P53 ◽  
Cycle Progression ◽  
Cycle Arrest ◽  
Colorectal Cancer Cells

Abstract Background Compound Kushen Injection (CKI) has been clinically used in China for 15 years to treat various types of solid tumors, including colorectal cancer. Here we examine cell cycle arrest, induced autophagy, and mutant p53 pathways perturbed by CKI in colorectal cancer cells. We and other groups have shown that CKI alters p53 gene expression patterns and suppresses proliferation in colorectal cancer cells. Methods We measured the effect of CKI on cell proliferation, cell cycle progression and autophagy in sw480 and sw620 colorectal cancer cells in vitro, and carcinogenesis and the progression of azoxymethane/dextran sodium sulfate-induced colorectal cancer in ICR mice in vivo. We also used RNA sequencing to analyze mRNA expression altered by CKI, and further validated the expression of mutant p53 and several genes in the cell cycle pathway using reverse transcriptase-quantitative PCR and western blotting. Using network pharmacology (BATMAN-TCM database), we have also predicted the active ingredients in CKI involved in regulating the expression of mutant p53. Results We show evidence that CKI significantly suppressed proliferation and cell cycle progression, and induced autophagy of sw480 and sw620 cells in vitro; it also inhibited the development of inflammatory colorectal cancer in vivo. We also show that the down-regulated expression of mutant p53 and adjustments in several key genes related closely to cell-cycle progression. Furthermore, N-oxysophocarpine, lupenone, and geranylacetone were predicted to be the active ingredients of CKI involved in the down-regulated expression of mutant p53. Conclusion Our results indicate that CKI likely acts as a potential anti-cancer therapeutic agent that targets the cell cycle pathway, suggesting a key role in the development of a novel subsidiary therapeutic approach against mutant p53 in patients with colorectal cancer.

scholarly journals The FACT complex and cell cycle progression are essential to maintain asymmetric transcription factor partitioning during cell division

2016 ◽  
Author(s):  
Eva Herrero ◽  
Sonia Stinus ◽  
Eleanor Bellows ◽  
Peter H Thorpe
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Cell Division ◽  
Cell Cycle Progression ◽  
Asymmetric Cell Division ◽  
Cycle Progression ◽  
Cellular Processes ◽  
Daughter Cells ◽  
Cycle Arrest ◽  
Reverse Genetic Screen

AbstractThe polarized partitioning of proteins in cells underlies asymmetric cell division, which is an important driver of development and cellular diversity. Like most cells, the budding yeast Saccharomyces cerevisiae divides asymmetrically to give two distinct daughter cells. This asymmetry mimics that seen in metazoans and the key regulatory proteins are conserved from yeast to human. A well-known example of an asymmetric protein is the transcription factor Ace2, which localizes specifically to the daughter nucleus, where it drives a daughter-specific transcriptional network. We performed a reverse genetic screen to look for regulators of asymmetry based on the Ace2 localization phenotype. We screened a collection of essential genes in order to analyze the effect of core cellular processes in asymmetric cell division. This identified a large number of mutations that are known to affect progression through the cell cycle, suggesting that cell cycle delay is sufficient to disrupt Ace2 asymmetry. To test this model we blocked cells from progressing through mitosis and found that prolonged cell cycle arrest is sufficient to disrupt Ace2 asymmetry after release. We also demonstrate that members of the evolutionary conserved FACT chromatin-remodeling complex are required for both asymmetric and cell cycle-regulated localization of Ace2.

scholarly journals Roquin1 inhibits the proliferation of breast cancer cells by inducing G1/S cell cycle arrest via selectively destabilizing the mRNAs of cell cycle–promoting genes

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Wenbao Lu ◽  
Meicen Zhou ◽  
Bing Wang ◽  
Xueting Liu ◽  
Bingwei Li
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Breast Tumor ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Cycle Arrest

Abstract Background Dysregulation of cell cycle progression is a common feature of human cancer cells; however, its mechanism remains unclear. This study aims to clarify the role and the underlying mechanisms of Roquin1 in cell cycle arrest in breast cancer. Methods Public cancer databases were analyzed to identify the expression pattern of Roquin1 in human breast cancers and its association with patient survival. Quantitative real-time PCR and Western blots were performed to detect the expression of Roquin1 in breast cancer samples and cell lines. Cell counting, MTT assays, flow cytometry, and in vivo analyses were conducted to investigate the effects of Roquin1 on cell proliferation, cell cycle progression and tumor progression. RNA sequencing was applied to identify the differentially expressed genes regulated by Roquin1. RNA immunoprecipitation assay, luciferase reporter assay, mRNA half-life detection, RNA affinity binding assay, and RIP-ChIP were used to explore the molecular mechanisms of Roquin1. Results We showed that Roquin1 expression in breast cancer tissues and cell lines was inhibited, and the reduction in Roquin1 expression was associated with poor overall survival and relapse-free survival of patients with breast cancer. Roquin1 overexpression inhibited cell proliferation and induced G1/S cell cycle arrest without causing significant apoptosis. In contrast, knockdown of Roquin1 promoted cell growth and cycle progression. Moreover, in vivo induction of Roquin1 by adenovirus significantly suppressed breast tumor growth and metastasis. Mechanistically, Roquin1 selectively destabilizes cell cycle–promoting genes, including Cyclin D1, Cyclin E1, cyclin dependent kinase 6 (CDK6) and minichromosome maintenance 2 (MCM2), by targeting the stem–loop structure in the 3′ untranslated region (3’UTR) of mRNAs via its ROQ domain, leading to the downregulation of cell cycle–promoting mRNAs. Conclusions Our findings demonstrated that Roquin1 is a novel breast tumor suppressor and could induce G1/S cell cycle arrest by selectively downregulating the expression of cell cycle–promoting genes, which might be a potential molecular target for breast cancer treatment.

scholarly journals HOPS/Tmub1 involvement in the NF-kB-mediated inflammatory response through the modulation of TRAF6

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Marina Maria Bellet ◽  
Stefania Pieroni ◽  
Marilena Castelli ◽  
Danilo Piobbico ◽  
Francesca Fallarino ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Inflammatory Responses ◽  
Cycle Progression ◽  
Cellular Events ◽  
Cycle Arrest ◽  
Ikk Complex ◽  
Inflammatory Processes ◽  
Important Regulator

Abstract HOPS/Tmub1 is a ubiquitously expressed transmembrane ubiquitin-like protein that shuttles between nucleus and cytoplasm during cell cycle progression. HOPS causes cell cycle arrest in G0/G1 phase, an event associated to stabilization of p19Arf, an important tumor suppressor protein. Moreover, HOPS plays an important role in driving centrosomal assembly and maintenance, mitotic spindle proper organization, and ultimately a correct cell division. Recently, HOPS has been described as an important regulator of p53, which acts as modifier, stabilizing p53 half-life and playing a key role in p53 mediating apoptosis after DNA damage. NF-κB is a transcription factor with a central role in many cellular events, including inflammation and apoptosis. Our experiments demonstrate that the transcriptional activity of the p65/RelA NF-κB subunit is regulated by HOPS. Importantly, Hops−/− cells have remarkable alterations of pro-inflammatory responses. Specifically, we found that HOPS enhances NF-κB activation leading to increase transcription of inflammatory mediators, through the reduction of IκBα stability. Notably, this effect is mediated by a direct HOPS binding to the E3 ubiquitin ligase TRAF6, which lessens TRAF6 stability ultimately leading increased IKK complex activation. These findings uncover a previously unidentified function of HOPS/Tmub1 as a novel modulator of TRAF6, regulating inflammatory responses driven by activation of the NF-κB signaling pathway. The comprehension on how HOPS/Tmub1 takes part to the inflammatory processes in vivo and whether this function is important in the control of proliferation and tumorigenesis could establish the basis for the development of novel pharmacological strategies.

scholarly journals Stabilization of p18 by deubiquitylase CYLD is pivotal for cell cycle progression and viral replication

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yueshuo Li ◽  
Feng Shi ◽  
Jianmin Hu ◽  
Longlong Xie ◽  
Lin Zhao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Viral Replication ◽  
Cell Cycle Progression ◽  
Negative Regulator ◽  
Protein Loss ◽  
Cycle Progression ◽  
Barr Virus ◽  
Cycle Arrest ◽  
Epstein Barr

Abstractp18 is a key negative regulator of cell cycle progression and mediates cell cycle arrest at the G1/S phase. Ubiquitination is the prime mechanism in regulating p18 protein abundance. However, so far no post- translational regulator, especially DUBs, has been identified to regulate the protein stability of p18. In this paper, we identified CYLD as a deubiquitinase of p18, which binds to and removes the K48-linked polyubiquitylation chains conjugated onto p18, thus stabilizing the p18 protein. Loss of CYLD causes the degradation of p18 and induces the G1/S transition. Epstein–Barr virus (EBV), is the human oncovirus etiologically linked to nasopharyngeal carcinoma (NPC). Here we found that EBV drives a replication passive environment by deregulating the CYLD-p18 axis. Functionally, CYLD inhibits cell proliferation and tumorigenesis through p18 in vivo. Restoring CYLD prevents EBV induced viral replication and tumor growth. Collectively, our results identify CYLD directly stabilizes p18 to regulate the cellular G1/S transition. The reconstitution of CYLD-p18 axis could be a promising approach for EBV-positive cancer therapy.

The Tem1 small GTPase controls actomyosin and septin dynamics during cytokinesis

2001 ◽  
Vol 114 (7) ◽  
pp. 1379-1386 ◽  
Author(s):  
J. Lippincott ◽  
K.B. Shannon ◽  
W. Shou ◽  
R.J. Deshaies ◽  
R. Li
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cell Cycle Progression ◽  
Small Gtpase ◽  
Contractile Ring ◽  
Cycle Progression ◽  
Septin Ring ◽  
Cycle Arrest ◽  
Ring Dynamics ◽  
Structural Barrier

Cytokinesis in budding yeast involves an actomyosin-based ring which assembles in a multistepped fashion during the cell cycle and constricts during cytokinesis. In this report, we have investigated the structural and regulatory events that occur at the onset of cytokinesis. The septins, which form an hour-glass like structure during early stages of the cell cycle, undergo dynamic rearrangements prior to cell division: the hourglass structure splits into two separate rings. The contractile ring, localized between the septin double rings, immediately undergoes contraction. Septin ring splitting is independent of actomyosin ring contraction as it still occurs in mutants where contraction fails. We hypothesize that septin ring splitting may remove a structural barrier for actomyosin ring to contract. Because the Tem1 small GTPase (Tem1p) is required for the completion of mitosis, we investigated its role in regulating septin and actomyosin ring dynamics in the background of the net1-1 mutation, which bypasses the anaphase cell cycle arrest in Tem1-deficient cells. We show that Tem1p plays a specific role in cytokinesis in addition to its function in cell cycle progression. Tem1p is not required for the assembly of the actomyosin ring but controls actomyosin and septin dynamics during cytokinesis.

Sign in / Sign up

Export Citation Format

Share Document