scholarly journals E2f3a and E2f3b Contribute to the Control of Cell Proliferation and Mouse Development

2008 ◽  
Vol 29 (2) ◽  
pp. 414-424 ◽  
Author(s):  
Jean-Leon Chong ◽  
Shih-Yin Tsai ◽  
Nidhi Sharma ◽  
Rene Opavsky ◽  
Richard Price ◽  
...  

ABSTRACT The E2f3 locus encodes two Rb-binding gene products, E2F3a and E2F3b, which are differentially regulated during the cell cycle and are thought to be critical for cell cycle progression. We targeted the individual inactivation of E2f3a or E2f3b in mice and examined their contributions to cell proliferation and development. Chromatin immunoprecipitation and gene expression experiments using mouse embryo fibroblasts deficient in each isoform showed that E2F3a and E2F3b contribute to G1/S-specific gene expression and cell proliferation. Expression of E2f3a or E2f3b was sufficient to support E2F target gene expression and cell proliferation in the absence of other E2F activators, E2f1 and E2f2, suggesting that these isoforms have redundant functions. Consistent with this notion, E2f3a −/− and E2f3b −/− embryos developed normally, whereas embryos lacking both isoforms (E2f3 −/−) died in utero. We also find that E2f3a and E2f3b have redundant and nonredundant roles in the context of Rb mutation. Analysis of double-knockout embryos suggests that the ectopic proliferation and apoptosis in Rb −/− embryos is mainly mediated by E2f3a in the placenta and nervous system and by both E2f3a and E2f3b in lens fiber cells. Together, we conclude that the contributions of E2F3a and E2F3b in cell proliferation and development are context dependent.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lionel Condé ◽  
Yulemi Gonzalez Quesada ◽  
Florence Bonnet-Magnaval ◽  
Rémy Beaujois ◽  
Luc DesGroseillers

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.


2020 ◽  
Author(s):  
Changbo Fu ◽  
Lei Nie ◽  
Tao Yin ◽  
Xuan Xu ◽  
weijun lu

Abstract Background: LncRNA EPIC1 is likely involved in human cancer by promoting cell cycle progression. Our study was carried out to investigate the involvement of EPIC1 in gallbladder cancer (GBC). Methods: Expression levels of EPIC1 in two types of tissues (GBC and paracancerous) and plasma were measured by performing qPCR. GBC-SD and SGC-996 cells were transfected with LET and EPIC1 expression vectors.Results: In the preset study we found that EPIC1 was upregulated in tumor tissues than in paracancerous tissues of GBC patients, and plasma levels of EPIC1 were significantly correlated with levels of EPIC1 in tumor tissues. LncRNA LET was downregulated in tumor tissues than in paracancerous tissues and was inversely correlated with EPIC1 in both tumor tissues and paracancerous tissues. Overexpression of EPIC1 led to downregulated LET, and LET overexpression also mediated the downregulation of EPIC1. EPIC1 led to accelerated GBC cell proliferation and inhibited apoptosis. Overexpression of LET played opposites roles. In addition, overexpression of LET also attenuated the effects of EPIC1 overexpression on cancer cell proliferation and apoptosis. Conclusion: Therefore, therefore, lncRNA EPIC1 may promote cancer cell proliferation and inhibit apoptosis in GBC by interacting with LET.


2020 ◽  
Author(s):  
Yuejiao Wang ◽  
Kailin Zhang ◽  
Xiaowei Yuan ◽  
Neili Xu ◽  
Shuai Zhao ◽  
...  

Abstract Background miR-431-5p is dysregulated in various cancers and plays an important function in the development of cancer. However, its role in fibroblast-like synoviocytes (FLSs) in patients with rheumatoid arthritis (RA) remains to be understood.Methods Quantitative real-time polymerase chain reaction was used to detect the relative expression of miR-431-5p in synovial tissues and FLSs. Cell proliferation assays helped examine RA FLS proliferation. Flow cytometry was performed to determine apoptosis and cell cycle progression in RA FLSs. We used dual-luciferase assays to determine the correlation between miR-431-5p and its putative target, X-linked inhibitor of apoptosis (XIAP). Quantitative real-time PCR and western blotting were used to measure XIAP levels in synovial tissues and transfected RA FLSs.Results miR-431-5p was downregulated in synovial tissues and FLSs of patients with RA. Upregulation of miR-431-5p prohibited cell proliferation and the G0/G1-to-S phase transition, but promoted apoptosis in RA FLSs; while miR-431-5p inhibition showed the opposite results. miR-431-5p directly targeted XIAP in RA FLSs, and reversely correlated with XIAP levels in synovial tissues. Notably, XIAP silencing partially restored the effects of miR-431-5p inhibition in RA FLSs.Conclusion miR-431-5p regulates cell proliferation, apoptosis,and cell cycle of RA FLSs by targeting XIAP, suggesting its potential in the treatment of RA.


2006 ◽  
Vol 282 (7) ◽  
pp. 4803-4811 ◽  
Author(s):  
Marc E. Lenburg ◽  
Anupama Sinha ◽  
Douglas V. Faller ◽  
Gerald V. Denis

The dual bromodomain protein Brd2 is closely related to the basal transcription factor TAFII250, which is essential for cyclin A transactivation and mammalian cell cycle progression. In transgenic mice, constitutive lymphoid expression of Brd2 causes a malignancy most similar to human diffuse large B cell lymphoma. We compare the genome-wide transcriptional expression profiles of these lymphomas with those of proliferating and resting normal B cells. Transgenic tumors reproducibly show differential expression of a large number of genes important for cell cycle control and lymphocyte biology; expression patterns are either tumor-specific or proliferation-specific. Several of their human orthologs have been implicated in human lymphomagenesis. Others correlate with human disease survival time. BRD2 is underexpressed in some subtypes of human lymphoma and these subtypes display a number of similarities to the BRD2-mediated murine tumors. We illustrate with a high degree of detail that cancer is more than rampant cellular proliferation, but involves the additional transcriptional mobilization of many genes, some of them poorly characterized, which show a tumor-specific pattern of gene expression.


2020 ◽  
pp. jcs.255950
Author(s):  
Patrick Partscht ◽  
Borhan Uddin ◽  
Elmar Schiebel

Budding yeast Cdc14 phosphatase has a central role in mitotic exit and cytokinesis. Puzzlingly, a uniform picture for the three human CDC14 paralogues hCDC14A, B and C in cell cycle control has not emerged to date. Redundant functions between the three hCDC14 phosphatases could explain this unclear picture. To address the possibility of redundancy, we tested expression of hCDC14 and analysed cell cycle progression of cells with single- and double-deletion in hCDC14 genes. Our data suggest that hCDC14C is not expressed in human RPE1 cells excluding a function in this cell line. Single- and double-knockouts (KO) of hCDC14A and hCDC14B in RPE1 cells indicate that both phosphatases are not important for the timing of mitotic phases, cytokinesis and cell proliferation. However, cycling hCDC14A KO and hCDC14B KO cells show altered ciliogenesis compared to WT cells. The cilia of cycling hCDC14A KO cells are longer, whereas hCDC14B KO cilia are more frequent and disassemble faster. In conclusion, this study demonstrates that the cell cycle functions of CDC14 proteins are not conserved between yeast and human cells.


2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Jie Ma ◽  
Xian-Bin Wang ◽  
Rui Li ◽  
Shu-Hong Xuan ◽  
Fang Wang ◽  
...  

Esophageal cancer (EC) remains an important health problem in China. In the present study, through the use of siRNA, specific gene knockdown of transcription factor 3 gene (TCF-3) was achieved in vitro and the effect of TCF-3 gene on human EC Eca-109 cell proliferation and apoptosis. Eca-109 cells were treated using negative control (NC) of siRNA against TCF-3 (siTCF-3) and siTCF-3 group. Colony formation assay was used to detect the colony formation ability in Eca-109 cells. MTT assay was used to measure the cell growth and viability, whereas BrDU assay was used to evaluate cell proliferation, and flow cytometry (FCM) to assess cell apoptosis. Reverse-transcription quantitative PCR (RT-qPCR) was applied to measure TCF-3 gene expression. Protein expressions of TCF-3, apoptosis-related proteins, Bcl-2, Bax, and caspase-3 were determined using Western blotting. Transfection of siTCF-3 successfully down-regulated TCF-3 gene expression. In addition, siTCF-3, reduced Eca-109 cell viability and proliferation, in a time-dependent manner, and inhibited progression of cell cycle from G0/G1 to S-stage. When treated with siTCF-3, the Eca-109 cells exhibited increased apoptosis, with up-regulated cleaved caspase and Bax expressions, whereas Bcl-2 expression was down-regulated. The present study shows that TCF-3 gene silencing inhibits Eca-109 cell growth and proliferation, suppresses cell cycle progression, and promotes apoptosis, which might serve as a new objective for EC treatment.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tomoyuki Yamanaka ◽  
Haruko Miyazaki ◽  
Asako Tosaki ◽  
Sankar N. Maity ◽  
Tomomi Shimogori ◽  
...  

AbstractA heterotrimeric transcription factor NF-Y is crucial for cell-cycle progression in various types of cells. In contrast, studies using NF-YA knockout mice have unveiled its essential role in endoplasmic reticulum (ER) homeostasis in neuronal cells. However, whether NF-Y modulates a different transcriptome to mediate distinct cellular functions remains obscure. Here, we knocked down NF-Y in two types of neuronal cells, neuro2a neuroblastoma cells and mouse brain striatal cells, and performed gene expression profiling. We found that down-regulated genes preferentially contained NF-Y-binding motifs in their proximal promoters, and notably enriched genes related to ER functions rather than those for cell cycle. This contrasts with the profiling data of HeLa and embryonic stem cells in which distinct down-regulation of cell cycle-related genes was observed. Clustering analysis further identified several functional clusters where populations of the down-regulated genes were highly distinct. Further analyses using chromatin immunoprecipitation and RNA-seq data revealed that the transcriptomic difference was not correlated with DNA binding of NF-Y but with splicing of NF-YA. These data suggest that neuronal cells have a different type of transcriptome in which ER-related genes are dominantly modulated by NF-Y, and imply that NF-YA splicing alteration could be involved in this cell type-specific gene modulation.


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