DEAD-Box RNA Helicases in Cell Cycle Control and Clinical Therapy

Cell cycle is regulated through numerous signaling pathways that determine whether cells will proliferate, remain quiescent, arrest, or undergo apoptosis. Abnormal cell cycle regulation has been linked to many diseases. Thus, there is an urgent need to understand the diverse molecular mechanisms of how the cell cycle is controlled. RNA helicases constitute a large family of proteins with functions in all aspects of RNA metabolism, including unwinding or annealing of RNA molecules to regulate pre-mRNA, rRNA and miRNA processing, clamping protein complexes on RNA, or remodeling ribonucleoprotein complexes, to regulate gene expression. RNA helicases also regulate the activity of specific proteins through direct interaction. Abnormal expression of RNA helicases has been associated with different diseases, including cancer, neurological disorders, aging, and autosomal dominant polycystic kidney disease (ADPKD) via regulation of a diverse range of cellular processes such as cell proliferation, cell cycle arrest, and apoptosis. Recent studies showed that RNA helicases participate in the regulation of the cell cycle progression at each cell cycle phase, including G1-S transition, S phase, G2-M transition, mitosis, and cytokinesis. In this review, we discuss the essential roles and mechanisms of RNA helicases in the regulation of the cell cycle at different phases. For that, RNA helicases provide a rich source of targets for the development of therapeutic or prophylactic drugs. We also discuss the different targeting strategies against RNA helicases, the different types of compounds explored, the proposed inhibitory mechanisms of the compounds on specific RNA helicases, and the therapeutic potential of these compounds in the treatment of various disorders.

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Evaluation of Terpenes Psiadin, Plectranthone, and Saudinolide as Selective Anti-Cancer Agents against Hepatic Carcinoma Cells

10.20944/preprints202012.0591.v1 ◽

2020 ◽

Author(s):

Khaled Y. Orabi ◽

Mohamed S. Abaza ◽

Rajaa Al-Attiyah ◽

Yunus A. Luqmani

Keyword(s):

Cell Cycle ◽

Cell Lines ◽

Cancer Cell ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Therapeutic Potential ◽

Cancer Cell Lines ◽

Chemotherapeutic Agents ◽

Isolation And Purification

: Plant-derived terpenes have aroused considerable interest as chemotherapeutic agents for a variety of diseases. This study aimed at the isolation and purification of the scarce terpenes psiadin, plectranthone and saudinolide from their respective plants, followed by the determination of antiproliferative activity, against hepatic cancer cell lines (HepG2, Hep3B), and the potential molecular mechanisms. Time- and dose-dependent cytotoxicity, evaluated using MTT and colony-forming assays, were exhibited by psiadin and plectranthone against the cancer cells. Flow cytometry showed that these two terpenes blocked cell cycle progression and induced mitochondrial-mediated apoptosis, particularly through increased cytochrome c and disruption of mitochondrial membrane potential. Additionally, they initiated the generation of reactive oxygen species as well as inhibiting NF-B. Psiadin lowered several essential cyclins and cyclin-dependent kinases and reduced RB activation. It was concluded that psiadin, in particular, has a significant therapeutic potential with the biggest advantage of differentiating between cancer and normal cells which is acutely lacking in current cytotoxic drugs. Its precise mode of action needs further investigation but appears predominantly to cause cell cycle arrest by interfering with cyclin production. It will be important to determine, in future studies, whether these terpenes will similarly inhibit other cancer cell lines and retain its activity against tumors in vivo.

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LMNB2 promotes the progression of colorectal cancer by silencing p21 expression

Cell Death and Disease ◽

10.1038/s41419-021-03602-1 ◽

2021 ◽

Vol 12 (4) ◽

Author(s):

Chen-Hua Dong ◽

Tao Jiang ◽

Hang Yin ◽

Hu Song ◽

Yi Zhang ◽

...

Keyword(s):

Colorectal Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Gene Set Enrichment Analysis ◽

Molecular Therapy ◽

Cycle Progression ◽

Cancer Tissues

AbstractColorectal cancer is the second common cause of death worldwide. Lamin B2 (LMNB2) is involved in chromatin remodeling and the rupture and reorganization of nuclear membrane during mitosis, which is necessary for eukaryotic cell proliferation. However, the role of LMNB2 in colorectal cancer (CRC) is poorly understood. This study explored the biological functions of LMNB2 in the progression of colorectal cancer and explored the possible molecular mechanisms. We found that LMNB2 was significantly upregulated in primary colorectal cancer tissues and cell lines, compared with paired non-cancerous tissues and normal colorectal epithelium. The high expression of LMNB2 in colorectal cancer tissues is significantly related to the clinicopathological characteristics of the patients and the shorter overall and disease-free cumulative survival. Functional analysis, including CCK8 cell proliferation test, EdU proliferation test, colony formation analysis, nude mouse xenograft, cell cycle, and apoptosis analysis showed that LMNB2 significantly promotes cell proliferation by promoting cell cycle progression in vivo and in vitro. In addition, gene set enrichment analysis, luciferase report analysis, and CHIP analysis showed that LMNB2 promotes cell proliferation by regulating the p21 promoter, whereas LMNB2 has no effect on cell apoptosis. In summary, these findings not only indicate that LMNB2 promotes the proliferation of colorectal cancer by regulating p21-mediated cell cycle progression, but also suggest the potential value of LMNB2 as a clinical prognostic marker and molecular therapy target.

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Murine Norovirus Replication Induces G0/G1Cell Cycle Arrest in Asynchronously Growing Cells

Journal of Virology ◽

10.1128/jvi.03673-14 ◽

2015 ◽

Vol 89 (11) ◽

pp. 6057-6066 ◽

Cited By ~ 16

Author(s):

Colin Davies ◽

Chris M. Brown ◽

Dana Westphal ◽

Joanna M. Ward ◽

Vernon K. Ward

Keyword(s):

Cell Cycle ◽

Viral Replication ◽

Host Cell ◽

Virus Replication ◽

Cell Cycle Progression ◽

Cycle Phase ◽

Murine Norovirus ◽

Cycle Progression ◽

Infected Cells ◽

Favorable Conditions

ABSTRACTMany viruses replicate most efficiently in specific phases of the cell cycle, establishing or exploiting favorable conditions for viral replication, although little is known about the relationship between caliciviruses and the cell cycle. Microarray and Western blot analysis of murine norovirus 1 (MNV-1)-infected cells showed changes in cyclin transcript and protein levels indicative of a G1phase arrest. Cell cycle analysis confirmed that MNV-1 infection caused a prolonging of the G1phase and an accumulation of cells in the G0/G1phase. The accumulation in G0/G1phase was caused by a reduction in cell cycle progression through the G1/S restriction point, with MNV-1-infected cells released from a G1arrest showing reduced cell cycle progression compared to mock-infected cells. MNV-1 replication was compared in populations of cells synchronized into specific cell cycle phases and in asynchronously growing cells. Cells actively progressing through the G1phase had a 2-fold or higher increase in virus progeny and capsid protein expression over cells in other phases of the cell cycle or in unsynchronized populations. These findings suggest that MNV-1 infection leads to prolonging of the G1phase and a reduction in S phase entry in host cells, establishing favorable conditions for viral protein production and viral replication. There is limited information on the interactions between noroviruses and the cell cycle, and this observation of increased replication in the G1phase may be representative of other members of theCaliciviridae.IMPORTANCENoroviruses have proven recalcitrant to growth in cell culture, limiting our understanding of the interaction between these viruses and the infected cell. In this study, we used the cell-culturable MNV-1 to show that infection of murine macrophages affects the G1/S cell cycle phase transition, leading to an arrest in cell cycle progression and an accumulation of cells in the G0/G1phase. Furthermore, we show that MNV replication is enhanced in the G1phase compared to other stages of the cell cycle. Manipulating the cell cycle or adapting to cell cycle responses of the host cell is a mechanism to enhance virus replication. To the best of our knowledge, this is the first report of a norovirus interacting with the host cell cycle and exploiting the favorable conditions of the G0/G1phase for RNA virus replication.

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Loss of MCU prevents mitochondrial fusion in G1-S phase and blocks cell cycle progression and proliferation

Science Signaling ◽

10.1126/scisignal.aav1439 ◽

2019 ◽

Vol 12 (579) ◽

pp. eaav1439 ◽

Cited By ~ 19

Author(s):

Olha M. Koval ◽

Emily K. Nguyen ◽

Velarchana Santhana ◽

Trevor P. Fidler ◽

Sara C. Sebag ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Cell Cycle Progression ◽

Mitochondrial Fission ◽

Mitochondrial Fusion ◽

Cycle Phase ◽

Wild Type ◽

Mitochondrial Fragmentation ◽

Cycle Progression ◽

Regulatory Circuit

The role of the mitochondrial Ca2+uniporter (MCU) in physiologic cell proliferation remains to be defined. Here, we demonstrated that the MCU was required to match mitochondrial function to metabolic demands during the cell cycle. During the G1-S transition (the cycle phase with the highest mitochondrial ATP output), mitochondrial fusion, oxygen consumption, and Ca2+uptake increased in wild-type cells but not in cells lacking MCU. In proliferating wild-type control cells, the addition of the growth factors promoted the activation of the Ca2+/calmodulin-dependent kinase II (CaMKII) and the phosphorylation of the mitochondrial fission factor Drp1 at Ser616. The lack of the MCU was associated with baseline activation of CaMKII, mitochondrial fragmentation due to increased Drp1 phosphorylation, and impaired mitochondrial respiration and glycolysis. The mitochondrial fission/fusion ratio and proliferation in MCU-deficient cells recovered after MCU restoration or inhibition of mitochondrial fragmentation or of CaMKII in the cytosol. Our data highlight a key function for the MCU in mitochondrial adaptation to the metabolic demands during cell cycle progression. Cytosolic CaMKII and the MCU participate in a regulatory circuit, whereby mitochondrial Ca2+uptake affects cell proliferation through Drp1.

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Size uniformity of animal cells is actively maintained by a p38 MAPK-dependent regulation of G1-length

10.1101/119867 ◽

2017 ◽

Author(s):

Shixuan Liu ◽

Miriam B. Ginzberg ◽

Nish Patel ◽

Marc Hild ◽

Bosco Leung ◽

...

Keyword(s):

Cell Cycle ◽

Cell Size ◽

P38 Mapk ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Mapk Pathway ◽

Small Cells ◽

Animal Cells ◽

Cycle Progression ◽

Size Uniformity

AbstractAnimal cells within a tissue typically display a striking regularity in their size. To date, the molecular mechanisms that control this uniformity are still unknown. We have previously shown that size uniformity in animal cells is promoted, in part, by size-dependent regulation of G1 length. To identify the molecular mechanisms underlying this process, we performed a large-scale small molecule screen and found that the p38 MAPK pathway is involved in coordinating cell size and cell cycle progression. Small cells display higher p38 activity and spend more time in G1 than larger cells. Inhibition of p38 MAPK leads to loss of the compensatory G1 length extension in small cells, resulting in faster proliferation, smaller cell size and increased size heterogeneity. We propose a model wherein the p38 pathway responds to changes in cell size and regulates G1 exit accordingly, to increase cell size uniformity.One-sentence summaryThe p38 MAP kinase pathway coordinates cell growth and cell cycle progression by lengthening G1 in small cells, allowing them more time to grow before their next division.

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Epigenetic regulations follow cell cycle progression during differentiation of human pluripotent stem cells

10.1101/2020.06.26.173211 ◽

2020 ◽

Author(s):

Pedro Madrigal ◽

Siim Pauklin ◽

Kim Jee Goh ◽

Rodrigo Grandy ◽

Anna Osnato ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Cell Fate ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Embryonic Stem ◽

Chromatin Accessibility ◽

Activator Protein 1 ◽

Cellular Division ◽

Mapk Signalling

AbstractMost mammalian stem cells undergo cellular division during their differentiation to produce daughter cells with a new cellular identity. However, the cascade of epigenetic events and molecular mechanisms occurring between successive cell divisions upon differentiation have not yet been described in detail due to technical limitations. Here, we address this question by taking advantage of the Fluorescent Ubiquitination-based Cell Cycle Indicator (FUCCI) reporter to develop a culture system allowing the differentiation of human Embryonic Stem Cells (hESCs) synchronised for their cell cycle. Using this approach, we have assessed the epigenome and transcriptome dynamics during the first two divisions leading to definitive endoderm. We first observed that transcription of key markers of differentiation occurs before division suggesting that differentiation is initiated during the progression of cell cycle. Furthermore, ATAC-seq shows a major decrease in chromatin accessibility after pluripotency exit indicating that the first event of differentiation is the inhibition of alternative cell fate. In addition, using digital genomic footprinting we identified novel cell cycle-specific transcription factors with regulatory potential in endoderm specification. Of particular interest, Activator protein 1 (AP-1) controlled p38/MAPK signalling seems to be necessary for blocking endoderm shifting cell fate toward mesoderm lineage. Finally, histone modifications analyses suggest a temporal order between different marks. We can also conclude that enhancers are dynamically and rapidly established / decommissioned between different cell cycle upon differentiation. Overall, these data not only reveal key the successive interplays between epigenetic modifications during differentiation but also provide a valuable resource to investigate novel mechanisms in germ layer specification.

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Silencing of miR-1246 Induces Cell Cycle Arrest and Apoptosis in Cisplatin-Resistant Ovarian Cancer Cells by Promoting ZNF23 Transcription

Cytogenetic and Genome Research ◽

10.1159/000520069 ◽

2021 ◽

pp. 1-13

Author(s):

Lu Cai ◽

Qian Zhang ◽

Lili Du ◽

Feiyun Zheng

Keyword(s):

Cell Cycle ◽

Ovarian Cancer ◽

Cell Proliferation ◽

Cell Cycle Arrest ◽

Cell Cycle Progression ◽

Luciferase Reporter ◽

Cycle Phase ◽

Ovarian Cancer Cells ◽

Tunel Staining ◽

Cycle Arrest

Ovarian cancer (OC) is the most frequent cause of death among patients with gynecologic malignancies. In recent years, the development of cisplatin (DDP) resistance has become an important reason for the poor prognosis of OC patients. Therefore, it is vital to explore the mechanism of DDP resistance in OC. In this study, microRNA-1246 (miR-1246) expression in OC and DDP-resistant OC cells was determined by RT-qPCR, and chemosensitivity to DDP was assessed by the CCK-8 assay. A dual-luciferase reporter assay was performed to confirm the interaction between miR-1246 and zinc finger 23 (ZNF23), while changes in ZNF23 expression were monitored by RT-qPCR, immunofluorescence, and western blot assays. Moreover, cell proliferation, cycle phase, and apoptosis were determined by EdU staining, flow cytometry, TUNEL staining, and Hoechst staining. Our data showed that miR-1246 was highly expressed in DDP-resistant OVCAR-3 and TOV-112D cells. Functionally, overexpression of miR-1246 markedly enhanced DDP resistance and cell proliferation, and suppressed cell cycle arrest and apoptosis of OC cells. Inhibition of miR-1246 expression significantly attenuated DDP resistance and cell proliferation, and increased cell cycle arrest and apoptosis in DDP-resistant OC cells. Furthermore, ZNF23 was identified as a target gene of miR-1246, and ZNF23 protein expression was notably downregulated in DDP-resistant OC cells. Moreover, overexpression of miR-1246 significantly downregulated the ZNF23 levels in OVCAR-3 and TOV-112D cells, and inhibition of miR-1246 upregulated the ZNF23 levels in the DDP-resistant OVCAR-3 and TOV-112D cells. In conclusion, miR-1246 might be a novel regulator of DDP-resistant OC that functions by regulating ZNF23 expression in DDP-resistant cells, as well as cell proliferation, cell cycle progression, and apoptosis.

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Abstract W P198: Sphingomyelin Synthases Regulate Neuronal Cell Proliferation and Cell Cycle Progression

Stroke ◽

10.1161/str.45.suppl_1.wp198 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

Umadevi V Wesley ◽

Daniel Tremmel ◽

Robert Dempsey

Keyword(s):

Cell Cycle ◽

Cell Cycle Regulation ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Neuronal Cell ◽

Artery Occlusion ◽

Cycle Progression ◽

Cycle Arrest ◽

Cycle Regulation ◽

Cerebral Artery Occlusion

Introduction: The molecular mechanisms of cerebral ischemia damage and protection are not completely understood, but a number of reports implicate the contribution of lipid metabolism and cell-cycle regulating proteins in stroke out come. We have previously shown that tricyclodecan-9-yl-xanthogenate (D609) resulted in increased ceramide levels after transient middle cerebral artery occlusion (tMCAO) in spontaneously hypertensive rat (SHR). We hypothesized that D609 induced cell cycle arrest probably by inhibiting sphingomyelin synthase (SMS). In this study, we examined the direct effects of SMS on cell cycle progression and proliferation of neuroblast cells. Methods: Ischemia was induced by middle cerebral artery occlusion (MCAO) and reperfusion. Expression levels were measured by western blot analysis, RT-PCR, and Immunofluorescence staining. SMS1 and 2 expressions were silenced by stable transfection with SMS1/2-targeted shRNA. Cell cycle analysis was performed using Flow cytometry. Data were analyzed using MODFIT cell cycle analysis program. Cell proliferation rate was measured by MTT assay. Results: We have identified that the expression of SMS1is significantly up-regulated in the ischemic hemisphere following MCAO. Neuro-2a cells transfected with SMS specific ShRNA acquired more neuronal like phenotype and exhibited decreased proliferation rate. Also, silencing of both SMS1 and 2 induced cell-cycle arrest as shown by significantly increased percentage of cells in G0/G1 and decreased proportion of cells in S-phase as compared to control cells. This was accompanied by up-regulation of cyclin-dependent kinase (Cdk) inhibitors p21 and decreased levels of phophorylated AKT levels. Furthermore, loss of SMS inhibited the migratory potential of Neuro 2a cells. Summary: Up-regulation of SMS under ischemic/reperfusion conditions suggests that this enzyme potentially contributes to cell cycle regulation and may contribute to maintaining neuronal cell population. Further studies may open up a new direction for identifying the molecular mechanisms of cell cycle regulation and protection following ischemic stroke

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DNA damage inhibits proteolysis of the B-type cyclin Clb5 in S. cerevisiae

Journal of Cell Science ◽

10.1242/jcs.110.15.1813 ◽

1997 ◽

Vol 110 (15) ◽

pp. 1813-1820

Author(s):

D. Germain ◽

J. Hendley ◽

B. Futcher

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Tyrosine Phosphorylation ◽

Cell Cycle Progression ◽

Cycle Phase ◽

Cycle Progression ◽

Ubiquitin Pathway ◽

Cyclin Dependent Kinases ◽

Transition Points ◽

Checkpoint Genes

Cell cycle progression is mediated by waves of specific cyclin dependent kinases (CDKs) in all eukaryotes. Cyclins are degraded by the ubiquitin pathway of proteolysis. The recent identification of several components of the cyclin proteolysis machinery has highlighted both the importance of proteolysis at multiple transition points in the cell cycle and the involvement of other substrates degraded by the same machinery. In this study, we have investigated the effects of DNA damage on the cyclin proteolytic machinery in Saccharomyces cerevisiae. We find that the half-life of the B-type cyclin Clb5 is markedly increased following DNA damage while that of G1 cyclins is not. This effect is independent of cell cycle phase. Clb5 turnover requires p34CDC28 activity. Stabilisation of Clb5 correlates with an increase in tyrosine phosphorylation of p34CDC28, but stabilisation does not require this tyrosine phosphorylation. The stabilisation is independent of the checkpoint genes Mec1 and Rad53. These observations establish a new link between the regulation of proteolysis and DNA damage.

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Mechanisms and therapeutic potential of interactions between human amyloids and viruses

Cellular and Molecular Life Sciences ◽

10.1007/s00018-020-03711-8 ◽

2020 ◽

Author(s):

Emiel Michiels ◽

Frederic Rousseau ◽

Joost Schymkowitz

Keyword(s):

Molecular Mechanisms ◽

Driving Forces ◽

Therapeutic Potential ◽

Direct Interaction ◽

Therapeutic Interventions ◽

Microbial Pathogens ◽

Amyloid Formation ◽

Sequence Specificity ◽

Affected Tissue ◽

Virus Interactions

AbstractThe aggregation of specific proteins and their amyloid deposition in affected tissue in disease has been studied for decades assuming a sole pathogenic role of amyloids. It is now clear that amyloids can also encode important cellular functions, one of which involves the interaction potential of amyloids with microbial pathogens, including viruses. Human expressed amyloids have been shown to act both as innate restriction molecules against viruses as well as promoting agents for viral infectivity. The underlying molecular driving forces of such amyloid–virus interactions are not completely understood. Starting from the well-described molecular mechanisms underlying amyloid formation, we here summarize three non-mutually exclusive hypotheses that have been proposed to drive amyloid–virus interactions. Viruses can indirectly drive amyloid depositions by affecting upstream molecular pathways or induce amyloid formation by a direct interaction with the viral surface or specific viral proteins. Finally, we highlight the potential of therapeutic interventions using the sequence specificity of amyloid interactions to drive viral interference.

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