Cell cycle progression: computer simulation of uncoupled subcycles of DNA replication and cell growth

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.

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Oncogenic role of ALX3 in cervical cancer cells through KDM2B-mediated histone demethylation of CDC25A

BMC Cancer ◽

10.1186/s12885-021-08552-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jinhong Qi ◽

Li Zhou ◽

Dongqing Li ◽

Jingyuan Yang ◽

He Wang ◽

...

Keyword(s):

Cell Cycle ◽

Cervical Cancer ◽

Cell Growth ◽

Cancer Cells ◽

Cell Cycle Progression ◽

Cervical Squamous Cell Carcinoma ◽

Cycle Progression ◽

Normal Tissues ◽

Positive Regulator ◽

Cervical Cancer Cells

Abstract Background Cell division cycle 25A (CDC25A) is a well-recognized regulator of cell cycle progression and is involved in cancer development. This work focused on the function of CDC25A in cervical cancer cell growth and the molecules involved. Methods A GEO dataset GSE63514 comprising data of cervical squamous cell carcinoma (CSCC) tissues was used to screen the aberrantly expressed genes in cervical cancer. The CDC25A expression in cancer and normal tissues was predicted in the GEPIA database and that in CSCC and normal cells was determined by RT-qPCR and western blot assays. Downregulation of CDC25A was introduced in CSCC cells to explore its function in cell growth and the cell cycle progression. The potential regulators of CDC25A activity and the possible involved signaling were explored. Results CDC25A was predicted to be overexpressed in CSCC, and high expression of CDC25A was observed in CSCC cells. Downregulation of CDC25A in ME180 and C33A cells reduced cell proliferation and blocked cell cycle progression, and it increased cell apoptosis. ALX3 was a positive regulator of CDC25A through transcription promotion. It recruited a histone demethylase, lysine demethylase 2B (KDM2B), to the CDC25A promoter, which enhanced CDC25A expression through demethylation of H3k4me3. Overexpression of ALX3 in cells blocked the inhibitory effects of CDC25A silencing. CDC25A was found as a positive regulator of the PI3K/Akt signaling pathway. Conclusion This study suggested that the ALX3 increased CDC25A expression through KDM2B-mediated demethylation of H3K4me3, which induced proliferation and cell cycle progression of cervical cancer cells.

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Deregulated expression of the RanBP1 gene alters cell cycle progression in murine fibroblasts

Journal of Cell Science ◽

10.1242/jcs.110.19.2345 ◽

1997 ◽

Vol 110 (19) ◽

pp. 2345-2357 ◽

Cited By ~ 1

Author(s):

A. Battistoni ◽

G. Guarguaglini ◽

F. Degrassi ◽

C. Pittoggi ◽

A. Palena ◽

...

Keyword(s):

Cell Cycle ◽

Dna Replication ◽

Cell Cycle Progression ◽

Protein Import ◽

Proliferating Cells ◽

Cycle Progression ◽

Ran Gtpase ◽

Genes Encoding ◽

Active Transcription ◽

Gtpase Cycle

RanBP1 is a molecular partner of the Ran GTPase, which is implicated in the control of several processes, including DNA replication, mitotic entry and exit, cell cycle progression, nuclear structure, protein import and RNA export. While most genes encoding Ran-interacting partners are constitutively active, transcription of the RanBP1 mRNA is repressed in non proliferating cells, is activated at the G1/S transition in cycling cells and peaks during S phase. We report here that forced expression of the RanBP1 gene disrupts the orderly execution of the cell division cycle at several stages, causing inhibition of DNA replication, defective mitotic exit and failure of chromatin decondensation during the telophase-to-interphase transition in cells that achieve nuclear duplication and chromosome segregation. These results suggest that deregulated RanBP1 activity interferes with the Ran GTPase cycle and prevents the functioning of the Ran signalling system during the cell cycle.

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Microarray gene expression profiling in colorectal (HCT116) and hepatocellular (HepG2) carcinoma cell lines treated withMelicope ptelefolialeaf extract reveals transcriptome profiles exhibiting anticancer activity

PeerJ ◽

10.7717/peerj.5203 ◽

2018 ◽

Vol 6 ◽

pp. e5203 ◽

Cited By ~ 6

Author(s):

Mohammad Faujul Kabir ◽

Johari Mohd Ali ◽

Onn Haji Hashim

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Dna Replication ◽

Cell Lines ◽

Microarray Data ◽

Expression Profiling ◽

Cell Cycle Progression ◽

Anticancer Activities ◽

Microarray Gene Expression ◽

Cycle Progression

BackgroundWe have previously reported anticancer activities ofMelicope ptelefolia(MP) leaf extracts on four different cancer cell lines. However, the underlying mechanisms of actions have yet to be deciphered. In the present study, the anticancer activity of MP hexane extract (MP-HX) on colorectal (HCT116) and hepatocellular carcinoma (HepG2) cell lines was characterized through microarray gene expression profiling.MethodsHCT116 and HepG2 cells were treated with MP-HX for 24 hr. Total RNA was extracted from the cells and used for transcriptome profiling using Applied Biosystem GeneChip™ Human Gene 2.0 ST Array. Gene expression data was analysed using an Applied Biosystems Expression Console and Transcriptome Analysis Console software. Pathway enrichment analyses was performed using Ingenuity Pathway Analysis (IPA) software. The microarray data was validated by profiling the expression of 17 genes through quantitative reverse transcription PCR (RT-qPCR).ResultsMP-HX induced differential expression of 1,290 and 1,325 genes in HCT116 and HepG2 cells, respectively (microarray data fold change, MA_FC ≥ ±2.0). The direction of gene expression change for the 17 genes assayed through RT-qPCR agree with the microarray data. In both cell lines, MP-HX modulated the expression of many genes in directions that support antiproliferative activity. IPA software analyses revealed MP-HX modulated canonical pathways, networks and biological processes that are associated with cell cycle, DNA replication, cellular growth and cell proliferation. In both cell lines, upregulation of genes which promote apoptosis, cell cycle arrest and growth inhibition were observed, while genes that are typically overexpressed in diverse human cancers or those that promoted cell cycle progression, DNA replication and cellular proliferation were downregulated. Some of the genes upregulated by MP-HX include pro-apoptotic genes (DDIT3, BBC3, JUN), cell cycle arresting (CDKN1A, CDKN2B), growth arrest/repair (TP53, GADD45A) and metastasis suppression (NDRG1). MP-HX downregulated the expression of genes that could promote anti-apoptotic effect, cell cycle progression, tumor development and progression, which include BIRC5, CCNA2, CCNB1, CCNB2, CCNE2, CDK1/2/6, GINS2, HELLS, MCM2/10 PLK1, RRM2 and SKP2. It is interesting to note that all six top-ranked genes proposed to be cancer-associated (PLK1, MCM2, MCM3, MCM7, MCM10 and SKP2) were downregulated by MP-HX in both cell lines.DiscussionThe present study showed that the anticancer activities of MP-HX are exerted through its actions on genes regulating apoptosis, cell proliferation, DNA replication and cell cycle progression. These findings further project the potential use of MP as a nutraceutical agent for cancer therapeutics.

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An Alternatively Translated Connexin 43 Isoform, GJA1-11k, Localizes to the Nucleus and Can Inhibit Cell Cycle Progression

Biomolecules ◽

10.3390/biom10030473 ◽

2020 ◽

Vol 10 (3) ◽

pp. 473

Author(s):

Irina Epifantseva ◽

Shaohua Xiao ◽

Rachel E. Baum ◽

André G. Kléber ◽

TingTing Hong ◽

...

Keyword(s):

Cell Cycle ◽

Cell Growth ◽

Gap Junction ◽

Connexin 43 ◽

Cell Cycle Progression ◽

Tumor Formation ◽

Full Length ◽

Cycle Progression ◽

Junction Protein ◽

Truncated Isoforms

Connexin 43 (Cx43) is a gap junction protein that assembles at the cell border to form intercellular gap junction (GJ) channels which allow for cell–cell communication by facilitating the rapid transmission of ions and other small molecules between adjacent cells. Non-canonical roles of Cx43, and specifically its C-terminal domain, have been identified in the regulation of Cx43 trafficking, mitochondrial preconditioning, cell proliferation, and tumor formation, yet the mechanisms are still being explored. It was recently identified that up to six truncated isoforms of Cx43 are endogenously produced via alternative translation from internal start codons in addition to full length Cx43, all from the same mRNA produced by the gene GJA1. GJA1-11k, the 11kDa alternatively translated isoform of Cx43, does not have a known role in the formation of gap junction channels, and little is known about its function. Here, we report that over expressed GJA1-11k, unlike the other five truncated isoforms, preferentially localizes to the nucleus in HEK293FT cells and suppresses cell growth by limiting cell cycle progression from the G0/G1 phase to the S phase. Furthermore, these functions are independent of the channel-forming full-length Cx43 isoform. Understanding the apparently unique role of GJA1-11k and its generation in cell cycle regulation may uncover a new target for affecting cell growth in multiple disease models.

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Distinct and sequential upregulation of genes regulating cell growth and cell cycle progression during hepatic ischemia-reperfusion injury

AJP Cell Physiology ◽

10.1152/ajpcell.00629.2004 ◽

2005 ◽

Vol 289 (4) ◽

pp. C826-C835 ◽

Cited By ~ 41

Author(s):

Sharon Barone ◽

Tomohisa Okaya ◽

Steve Rudich ◽

Snezana Petrovic ◽

Kathy Tenrani ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Cell Growth ◽

Reperfusion Injury ◽

Cell Cycle Progression ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Catabolic Pathway ◽

Cycle Progression

Ischemia-reperfusion injury (IRI) in liver and other organs is manifested as an injury phase followed by recovery and resolution. Control of cell growth and proliferation is essential for recovery from the injury. We examined the expression of three related regulators of cell cycle progression in liver IRI: spermidine/spermine N-acetyltransferase (SSAT), p21 (a cyclin-dependent kinase inhibitor), and stathmin. Mice were subjected to hepatic IRI, and liver tissues were harvested at timed intervals. The expression of SSAT, the rate-limiting enzyme in the polyamine catabolic pathway, had increased fivefold 6 h after IRI and correlated with increased putrescine levels in the liver, consistent with increased SSAT enzymatic activity in IRI. The expression of p21, which is transactivated by p53, was undetectable in sham-operated animals but was heavily induced at 12 and 24 h of reperfusion and declined to undetectable baseline levels at 72 h of reperfusion. The interaction of the polyamine pathway with the p53-p21 pathway was shown in vitro, where activation of SSAT with polyamine analog or the addition of putrescine to cultured hepatocytes induced the expression of p53 and p21 and decreased cell viability. The expression of stathmin, which is under negative transcriptional regulation by p21 and controls cell proliferation and progression through mitosis, remained undetectable at 6, 12, and 24 h of reperfusion and was progressively and heavily induced at 48 and 72 h of reperfusion. Double-immunofluorescence labeling with antibodies against stathmin and PCNA, a marker of cell proliferation, demonstrated colocalization of stathmin and PCNA at 48 and 72 h of reperfusion in hepatocytes, indicating the initiation of cell proliferation. The distinct and sequential upregulation of SSAT, p21, and stathmin, along with biochemical activation of the polyamine catabolic pathway in IRI in vivo and the demonstration of p53-p21 upregulation by SSAT and putrescine in vitro, points to the important role of regulators of cell growth and cell cycle progression in the pathophysiology and/or recovery in liver IRI. The data further suggest that SSAT may play a role in the initiation of injury, whereas p21 and stathmin may be involved in the resolution and recovery after liver IRI.

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