scholarly journals MiR-15b Targets Cyclin D1 to Regulate Proliferation and Apoptosis in Glioma Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Guan Sun ◽  
Lei Shi ◽  
Shushan Yan ◽  
Zhengqiang Wan ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cell Cycle Progression ◽  
Therapeutic Strategy ◽  
Glioma Cells ◽  
Luciferase Assay ◽  
Luciferase Reporter ◽  
Cycle Progression ◽  
Cycle Arrest ◽  
Proliferation And Apoptosis

Aim. To investigate the role and mechanism of miR-15b in the proliferation and apoptosis of glioma.Methods. The miR-15b mimics were transfected into human glioma cells to upregulate the miR-15b expression. Cyclin D1 was determined by both western blotting analysis and luciferase reporter assay. Methylthiazol tetrazolium (MTT) and flow cytometry were employed to detect the cell proliferation, cell cycle, and apoptosis.Results. Overexpression of miR-15b inhibits proliferation by arrested cell cycle progression and induces apoptosis, possibly by directly targeting Cyclin D1. Both luciferase assay and bioinformatics search revealed a putative target site of miR-15b binding to the 3′-UTR of Cyclin D1. Moreover, expression of miR-15b in glioma tissues was found to be inversely correlated with Cyclin D1 expression. Enforced Cyclin D1 could abrogate the miR-15b-mediated cell cycle arrest and apoptosis.Conclusions. Our findings identified that miR-15b may function as a glioma suppressor by targeting the Cyclin D1, which may provide a novel therapeutic strategy for treatment of glioma.

scholarly journals Id2 specifically alters regulation of the cell cycle by tumor suppressor proteins.

1996 ◽  
Vol 16 (6) ◽  
pp. 2570-2578 ◽  
Author(s):  
A Lasorella ◽  
A Iavarone ◽  
M A Israel
Keyword(s):  
Cell Cycle ◽  
Tumor Suppressor ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cell Cycle Progression ◽  
D1 Protein ◽  
Protein Kinase Activity ◽  
Cycle Progression ◽  
Tumor Suppressor Proteins ◽  
Cycle Arrest

Cells which are highly proliferative typically lack expression of differentiated, lineage-specific characteristics. Id2, a member of the helix-loop-helix (HLH) protein family known to inhibit cell differentiation, binds to the retinoblastoma protein (pRb) and abolishes its growth-suppressing activity. We found that Id2 but not Id1 or Id3 was able to bind in vitro not only pRb but also the related proteins p107 and p130. Also, an association between Id2 and p107 or p130 was observed in vivo in transiently transfected Saos-2 cells. In agreement with these results, expression of Id1 or Id3 did not affect the block of cell cycle progression mediated by pRb. Conversely, expression of Id2 specifically reversed the cell cycle arrest induced by each of the three members of the pRb family. Furthermore, the growth-suppressive activities of cyclin-dependent kinase inhibitors p16 and p21 were efficiently antagonized by high levels of Id2 but not by Id1 Id3. Consistent with the role of p16 as a selective inhibitor of pRb and pRb-related protein kinase activity, p16-imposed cell cycle arrest was completely abolished by Id2. Only a partial reversal of p21-induced growth suppression was observed, which correlated with the presence of a functional pRb. We also documented decreased levels of cyclin D1 protein and mRNA and the loss of cyclin D1-cdk4 complexes in cells constitutively expressing Id2. These data provide evidence for important Id2-mediated alterations in cell cycle components normally involved in the regulatory events of cell cycle progression, and they highlight a specific role for Id2 as an antagonist of multiple tumor suppressor proteins.

scholarly journals PSMC2 Regulates Cell Cycle Progression Through the p21/Cyclin D1 Pathway and Predicts a Poor Prognosis in Human Hepatocellular Carcinoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Yiwei Liu ◽  
Hairong Chen ◽  
Xiangcheng Li ◽  
Feng Zhang ◽  
Lianbao Kong ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cyclin D1 ◽  
Cell Cycle Progression ◽  
Cox Regression ◽  
Disease Free Survival ◽  
Luciferase Reporter ◽  
Cycle Progression ◽  
Cox Regression Analysis

Proteasome 26S subunit ATPase 2 (PSMC2) plays a pathogenic role in various cancers. However, its function and molecular mechanism in hepatocellular carcinoma (HCC) remain unknown. In this study, tissue microarray (TMA) analysis showed that PSMC2 is highly expressed in HCC tumors and correlates with poor overall and disease-free survival in HCC patients. Multivariate Cox regression analysis revealed that PSMC2 is an independent prognostic factor for HCC patients. Furthermore, our results showed that PSMC2 knockdown inhibited cell proliferation and suppressed tumorigenesis in vivo. Knockdown of PSMC2 increased the expression of p21 and therefore decreased the expression of cyclin D1. Dual-luciferase reporter assays indicated that depletion of PSMC2 significantly enhanced the promoter activity of p21. Importantly, PSMC2 knockdown-induced phenotypes were also rescued by downregulation of P21. Taken together, our data suggest that PSMC2 promotes HCC cell proliferation and cell cycle progression through the p21/cyclin D1 signaling pathway and could be a promising diagnostic and therapeutic target for HCC patients.

scholarly journals Raf-induced proliferation or cell cycle arrest is determined by the level of Raf activity with arrest mediated by p21Cip1.

1997 ◽  
Vol 17 (9) ◽  
pp. 5598-5611 ◽  
Author(s):  
D Woods ◽  
D Parry ◽  
H Cherwinski ◽  
E Bosch ◽  
E Lees ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Mammalian Cells ◽  
Cell Cycle Progression ◽  
Cyclin E ◽  
G1 Arrest ◽  
Cycle Progression ◽  
Cycle Arrest ◽  
Primary Mouse

The Raf family of protein kinases display differences in their abilities to promote the entry of quiescent NIH 3T3 cells into the S phase of the cell cycle. Although conditional activation of deltaA-Raf:ER promoted cell cycle progression, activation of deltaRaf-1:ER and deltaB-Raf:ER elicited a G1 arrest that was not overcome by exogenously added growth factors. Activation of all three deltaRaf:ER kinases led to elevated expression of cyclin D1 and cyclin E and reduced expression of p27Kip1. However, activation of deltaB-Raf:ER and deltaRaf-1:ER induced the expression of p21Cip1, whereas activation of deltaA-Raf:ER did not. A catalytically potentiated form of deltaA-Raf:ER, generated by point mutation, strongly induced p21Cip1 expression and elicited cell cycle arrest similarly to deltaB-Raf:ER and deltaRaf-1:ER. These data suggested that the strength and duration of signaling by Raf kinases might influence the biological outcome of activation of this pathway. By titration of deltaB-Raf:ER activity we demonstrated that low levels of Raf activity led to activation of cyclin D1-cdk4 and cyclin E-cdk2 complexes and to cell cycle progression whereas higher Raf activity elicited cell cycle arrest correlating with p21Cip1 induction and inhibition of cyclin-cdk activity. Using green fluorescent protein-tagged forms of deltaRaf-1:ER in primary mouse embryo fibroblasts (MEFs) we demonstrated that p21Cip1 was induced by Raf in a p53-independent manner, leading to cell cycle arrest. By contrast, activation of Raf in p21Cip1(-/-) MEFs led to a robust mitogenic response that was similar to that observed in response to platelet-derived growth factor. These data indicate that, depending on the level of kinase activity, Raf can elicit either cell cycle progression or cell cycle arrest in mouse fibroblasts. The ability of Raf to elicit cell cycle arrest is strongly associated with its ability to induce the expression of the cyclin-dependent kinase inhibitor p21Cip1 in a manner that bears analogy to alpha-factor arrest in Saccharomyces cerevisiae. These data are consistent with a role for Raf kinases in both proliferation and differentiation of mammalian cells.

scholarly journals Osthole Alleviates Neointimal Hyperplasia in Balloon-Induced Arterial Wall Injury by Suppressing Vascular Smooth Muscle Cell Proliferation and Downregulating Cyclin D1/CDK4 and Cyclin E1/CDK2 Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Yi-Qi Li ◽  
Ye-Li Li ◽  
Xiao-Tong Li ◽  
Jun-Yuan Lv ◽  
Yang Gao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cell Cycle Progression ◽  
Neointimal Hyperplasia ◽  
Cycle Progression ◽  
Vsmc Proliferation ◽  
Cyclin E1 ◽  
Cycle Arrest ◽  
Wall Injury ◽  
Cdk2 Expression

Percutaneous coronary intervention (PCI) is the most widely used therapy for treating ischemic heart disease. However, intimal hyperplasia and restenosis usually occur within months after angioplasty. Modern pharmacological researchers have proven that osthole, the major active coumarin of Cnidium monnieri (L.) Cusson, exerts potent antiproliferative effects in lung cancer cells, the human laryngeal cancer cell line RK33 and TE671 medulloblastoma cells, and its mechanism of action is related to cell cycle arrest. The goal of the present study was to observe the effect of osthole on vascular smooth muscle cell (VSMC) proliferation using platelet-derived growth factor-BB (PDGF-BB)-stimulated VSMCs isolated from rats and vascular balloon injury as models to further elucidate the molecular mechanisms underlying this activity. We detected the relative number of VSMCs by the MTT assay and EdU staining and examined cell cycle progression by flow cytometry. To more deeply probe the mechanisms, the protein expression levels of PCNA, the cyclin D1/CDK4 complex and the cyclin E1/CDK2 complex in balloon-treated rat carotid arteries and the mRNA and protein expression levels of the cyclin D1/CDK4 and cyclin E1/CDK2 complexes in VSMCs were detected by real-time RT-PCR and western blotting. The data showed that osthole significantly inhibited the proliferation of VSMCs induced by PDGF-BB. Furthermore, osthole caused apparent VSMC cycle arrest early in G0/G1 phase and decreased the expression of cyclin D1/CDK4 and cyclin E1/CDK2. Our results demonstrate that osthole can significantly inhibit PDGF-BB-induced VSMC proliferation and that its regulatory effects on cell cycle progression and proliferation may be related to the downregulation of cyclin D1/CDK4 and cyclin E1/CDK2 expression as well as the prevention of cell cycle progression from G0/G1 phase to S phase. The abovementioned mechanism may be responsible for the alleviation of neointimal hyperplasia in balloon-induced arterial wall injury by osthole.

scholarly journals The RASSF1A Tumor Suppressor Blocks Cell Cycle Progression and Inhibits Cyclin D1 Accumulation

2002 ◽  
Vol 22 (12) ◽  
pp. 4309-4318 ◽  
Author(s):  
Latha Shivakumar ◽  
John Minna ◽  
Toshiyuki Sakamaki ◽  
Richard Pestell ◽  
Michael A. White
Keyword(s):  
Cell Cycle ◽  
Tumor Suppressor ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
S Phase ◽  
Phase Cell ◽  
Cycle Progression ◽  
Cycle Arrest

ABSTRACT The RASSF1A locus at 3p21.3 is epigenetically inactivated at high frequency in a variety of solid tumors. Expression of RASSF1A is sufficient to revert the tumorigenicity of human cancer cell lines. We show here that RASSF1A can induce cell cycle arrest by engaging the Rb family cell cycle checkpoint. RASSF1A inhibits accumulation of native cyclin D1, and the RASSF1A-induced cell cycle arrest can be relieved by ectopic expression of cyclin D1 or of other downstream activators of the G1/S-phase transition (cyclin A and E7). Regulation of cyclin D1 is responsive to native RASSF1A activity, because RNA interference-mediated downregulation of endogenous RASSF1A expression in human epithelial cells results in abnormal accumulation of cyclin D1 protein. Inhibition of cyclin D1 by RASSF1A occurs posttranscriptionally and is likely at the level of translational control. Rare alleles of RASSF1A, isolated from tumor cell lines, encode proteins that fail to block cyclin D1 accumulation and cell cycle progression. These results strongly suggest that RASSF1A is an important human tumor suppressor protein acting at the level of G1/S-phase cell cycle progression.

scholarly journals PARP14 regulates cyclin D1 expression to promote cell-cycle progression

Oncogene ◽  
2021 ◽  
Author(s):  
Michael J. O’Connor ◽  
Tanay Thakar ◽  
Claudia M. Nicolae ◽  
George-Lucian Moldovan
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Promote Cell Cycle Progression

scholarly journals Hyperbaric oxygen promotes not only glioblastoma proliferation but also chemosensitization by inhibiting HIF1α/HIF2α-Sox2

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Pan Wang ◽  
Sheng Gong ◽  
Jinyu Pan ◽  
Junwei Wang ◽  
Dewei Zou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Hyperbaric Oxygen ◽  
Cell Cycle Progression ◽  
Malignant Progression ◽  
Cycle Progression ◽  
Chemotherapy Sensitivity ◽  
Hypoxic Conditions ◽  
Cycle Arrest

AbstractThere exists a consensus that combining hyperbaric oxygen (HBO) and chemotherapy promotes chemotherapy sensitivity in GBM cells. However, few studies have explored the mechanism involved. HIF1α and HIF2α are the two main molecules that contribute to GBM malignant progression by inhibiting apoptosis or maintaining stemness under hypoxic conditions. Moreover, Sox2, a marker of stemness, also contributes to GBM malignant progression through stemness maintenance or cell cycle arrest. Briefly, HIF1α, HIF2α and Sox2 are highly expressed under hypoxia and contribute to GBM growth and chemoresistance. However, after exposure to HBO for GBM, whether the expression of the above factors is decreased, resulting in chemosensitization, remains unknown. Therefore, we performed a series of studies and determined that the expression of HIF1α, HIF2α and Sox2 was decreased after HBO and that HBO promoted GBM cell proliferation through cell cycle progression, albeit with a decrease in stemness, thus contributing to chemosensitization via the inhibition of HIF1α/HIF2α-Sox2.

scholarly journals Influenza A Virus Replication Induces Cell Cycle Arrest in G0/G1 Phase

2010 ◽  
Vol 84 (24) ◽  
pp. 12832-12840 ◽  
Author(s):  
Yuan He ◽  
Ke Xu ◽  
Bjoern Keiner ◽  
Jianfang Zhou ◽  
Volker Czudai ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Influenza A Virus ◽  
Influenza A ◽  
Cell Cycle Progression ◽  
Virus Production ◽  
Phase Cell ◽  
Cycle Progression ◽  
Cycle Arrest ◽  
Infected Cells

ABSTRACT Many viruses interact with the host cell division cycle to favor their own growth. In this study, we examined the ability of influenza A virus to manipulate cell cycle progression. Our results show that influenza A virus A/WSN/33 (H1N1) replication results in G0/G1-phase accumulation of infected cells and that this accumulation is caused by the prevention of cell cycle entry from G0/G1 phase into S phase. Consistent with the G0/G1-phase accumulation, the amount of hyperphosphorylated retinoblastoma protein, a necessary active form for cell cycle progression through late G1 into S phase, decreased after infection with A/WSN/33 (H1N1) virus. In addition, other key molecules in the regulation of the cell cycle, such as p21, cyclin E, and cyclin D1, were also changed and showed a pattern of G0/G1-phase cell cycle arrest. It is interesting that increased viral protein expression and progeny virus production in cells synchronized in the G0/G1 phase were observed compared to those in either unsynchronized cells or cells synchronized in the G2/M phase. G0/G1-phase cell cycle arrest is likely a common strategy, since the effect was also observed in other strains, such as H3N2, H9N2, PR8 H1N1, and pandemic swine H1N1 viruses. These findings, in all, suggest that influenza A virus may provide favorable conditions for viral protein accumulation and virus production by inducing a G0/G1-phase cell cycle arrest in infected cells.

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.

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