scholarly journals Bombyx mori Dihydroorotate Dehydrogenase: Knockdown Inhibits Cell Growth and Proliferation via Inducing Cell Cycle Arrest

2018 ◽  
Vol 19 (9) ◽  
pp. 2581 ◽  
Author(s):  
Erhu Zhao ◽  
Xiaolan Jiang ◽  
Hongjuan Cui
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Dna Replication ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Bombyx Mori ◽  
Dihydroorotate Dehydrogenase ◽  
Pyrimidine Synthesis ◽  
Cycle Arrest ◽  
Cell Growth And Proliferation

Dihydroorotate dehydrogenase (DHODH), in the de novo pyrimidine biosynthetic pathway, is the fourth enzyme of pyrimidine synthesis and is used to oxidize dihydroorotate and hence to orotat. We cloned and characterized here the dhod of silkworms, Bombyx mori. The full-length cDNA sequence of dhod is 1339 bp, including an open reading frame (ORF) of 1173 bp that encoded a 390 amino acid protein. And two domains were involved in the Dihydroorotate dehydrogenase amino acid sequence of silkworms, Bombyx mori (BmDHODH), namely a DHO_dh domain and a transmembrane domain in N-termina. The silkworm dhod is expressed throughout development and in nine tissues. Moreover, knockdown of the silkworm dhod gene reduced cell growth and proliferation through G2/M phase cell cycle arrest. Similarly, DHODH inhibitor (leflunomide) also reduced cell growth and proliferation, with a significant decrease of cyclin B and cdk2. DHODH is the fourth enzyme of pyrimidine synthesis, so we also found that leflunomide can inhibit, at least in part, the endomitotic DNA replication in silk glands cells. These findings demonstrate that downregulation of BmDHODH inhibits cell growth and proliferation in silkworm cells, and the endomitotic DNA replication in silk gland cells.

Jab1-siRNA Induces Cell Growth Inhibition and Cell Cycle Arrest in Gall Bladder Cancer Cells via Targeting Jab1 Signalosome

2020 ◽  
Vol 19 (16) ◽  
pp. 2019-2033 ◽  
Author(s):  
Pratibha Pandey ◽  
Mohammad H. Siddiqui ◽  
Anu Behari ◽  
Vinay K. Kapoor ◽  
Kumudesh Mishra ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bladder Cancer ◽  
Cell Growth ◽  
Gall Bladder ◽  
Growth Inhibition ◽  
Cell Cycle Arrest ◽  
Gall Bladder Cancer ◽  
Cell Growth Inhibition ◽  
Cycle Arrest ◽  
Apoptotic Induction

Background: The aberrant alteration in Jab1 signalosome (COP9 Signalosome Complex Subunit 5) has been proven to be associated with the progression of several carcinomas. However the specific role and mechanism of action of Jab1 signalosome in carcinogenesis of gall bladder cancer (GBC) are poorly understood. Objective: The main objective of our study was to elucidate the role and mechanism of Jab1 signalosome in gall bladder cancer by employing siRNA. Methods: Jab1 overexpression was identified in gall bladder cancer tissue sample. The role of Jab1-siRNA approach in cell growth inhibition and apoptotic induction was then examined by RT-PCR, Western Blotting, MTT, ROS, Hoechst and FITC/Annexin-V staining. Results: In the current study, we have shown that overexpression of Jab1 stimulated the proliferation of GBC cells; whereas downregulation of Jab1 by using Jab1-siRNA approach resulted incell growth inhibition and apoptotic induction. Furthermore, we found that downregulation of Jab1 induces cell cycle arrest at G1 phase and upregulated the expression of p27, p53 and Bax gene. Moreover, Jab1-siRNA induces apoptosis by enhancing ROS generation and caspase-3 activation. In addition, combined treatment with Jab1-siRNA and gemicitabine demonstrated an enhanced decline in cell proliferation which further suggested increased efficacy of gemcitabine at a very lower dose (5μM) in combination with Jab1-siRNA. Conclusion: In conclusion, our study strongly suggests that targeting Jab1 signalosome could be a promising therapeutic target for the treatment of gall bladder cancer.

scholarly journals ei24, a p53 Response Gene Involved in Growth Suppression and Apoptosis

2000 ◽  
Vol 20 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Zhengming Gu ◽  
Cathy Flemington ◽  
Thomas Chittenden ◽  
Gerard P. Zambetti
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Tumor Suppressor ◽  
Cell Cycle Arrest ◽  
Apoptotic Cell ◽  
Functional Characterization ◽  
Growth Control ◽  
P53 Tumor Suppressor ◽  
Cycle Arrest ◽  
P53 Response

ABSTRACT DNA damage and/or hyperproliferative signals activate the wild-type p53 tumor suppressor protein, which induces a G1 cell cycle arrest or apoptosis. Although the mechanism of p53-mediated cell cycle arrest is fairly well defined, the p53-dependent pathway regulating apoptosis is poorly understood. Here we report the functional characterization of murine ei24 (also known asPIG8), a gene directly regulated by p53, whose overexpression negatively controls cell growth and induces apoptotic cell death. Ectopic ei24 expression markedly inhibits cell colony formation, induces the morphological features of apoptosis, and reduces the number of β-galactosidase-marked cells, which is efficiently blocked by coexpression of Bcl-XL. Theei24/PIG8 gene is localized on human chromosome 11q23, a region frequently altered in human cancers. These results suggest that ei24 may play an important role in negative cell growth control by functioning as an apoptotic effector of p53 tumor suppressor activities.

Inhibition of cell growth and induction of G1-phase cell cycle arrest in hepatoma cells by steroid extract from Meretrix meretrix

2006 ◽  
Vol 232 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Ting-He Wu ◽  
Ruo-Lin Yang ◽  
Li-Ping Xie ◽  
Hong-Zhong Wang ◽  
Lei Chen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Hepatoma Cells ◽  
Phase Cell ◽  
G1 Phase ◽  
Meretrix Meretrix ◽  
Cycle Arrest

scholarly journals MiR-140-5p suppresses retinoblastoma cell growth via inhibiting c-Met/AKT/mTOR pathway

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Yujun Liao ◽  
Xiaolong Yin ◽  
Yan Deng ◽  
Xiaowei Peng
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Large Set ◽  
Retinoblastoma Cell ◽  
Cycle Arrest ◽  
Potential Biomarker ◽  
N Classification ◽  
Mirnas Expression ◽  
T Classification

MiR-140-5p is low expression and acts as a tumor suppressor in various types of human cancers. However, the potential role of miR-140-5p in retinoblastoma (RB) remains unknown. In the present study, we performed the miRNA microarray analysis to investigate whether miRNAs expression are associated with RB tumorigenesis in RB tissues. We found that a large set of miRNAs were ectopic expressions and miR-140-5p is most significantly down-regulated in human RB tissues compared with normal retinas. In addition, low miR-140-5p expression is associated with clinicopathological features (differentiation, invasion, T classification, N classification, cTNM stage, and largest tumor base) and poor survival in RB patients. Furthermore, our results showed that overexpression of miR-140-5p suppresses proliferation and induces apoptosis and cell cycle arrest in RB cell. Meanwhile, we confirmed that c-Met is the functional target of miR-140-5p in RB cell, and miR-140-5p expression is negatively correlated with c-Met in RB tissues. We also found that inhibition of c-Met also suppresses proliferation and induces apoptosis and cell cycle arrest in RB cell. Interestingly, c-Met can rescue the suppressive effects of miR-140-5p on RB cell growth and cell cycle arrest. More importantly, our findings indicated that miR-140-5p may inhibit cell growth via blocking c-Met/AKT/mTOR signaling pathway. Collectively, these results suggested that miR-140-5p might be a potential biomarker and target in the diagnosis and treatment of RB.

E4F1 silencing inhibits the cell growth through cell‐cycle arrest in malignant transformed cells induced by hydroquinone

2018 ◽  
Vol 33 (4) ◽  
pp. e22269 ◽  
Author(s):  
Qiang Tan ◽  
Jieyou Li ◽  
Jianming Peng ◽  
Zhidong Liu ◽  
Jiaxian Liu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Transformed Cells ◽  
Cycle Arrest

12-Deoxyphorbol 13-palmitate mediated cell growth inhibition, G2-M cell cycle arrest and apoptosis in BGC823 cells

2013 ◽  
Vol 700 (1-3) ◽  
pp. 13-22 ◽  
Author(s):  
Hui-Yu Xu ◽  
Zhi-Wei Chen ◽  
He Li ◽  
Li Zhou ◽  
Feng Liu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Growth Inhibition ◽  
Cell Cycle Arrest ◽  
Cell Growth Inhibition ◽  
M Cell ◽  
Cycle Arrest

scholarly journals Growth Suppression by Acute PromyelocyticLeukemia-Associated Protein PLZF Is Mediated by Repression ofc-mycExpression

2003 ◽  
Vol 23 (24) ◽  
pp. 9375-9388 ◽  
Author(s):  
Melanie J. McConnell ◽  
Nathalie Chevallier ◽  
Windy Berkofsky-Fessler ◽  
Jena M. Giltnane ◽  
Rupal B. Malani ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Target Genes ◽  
Ectopic Expression ◽  
Growth Suppression ◽  
Quiescent State ◽  
Cycle Arrest

ABSTRACT The transcriptional repressor PLZF was identified by its translocation with retinoic acid receptor alpha in t(11;17) acute promyelocytic leukemia (APL). Ectopic expression of PLZF leads to cell cycle arrest and growth suppression, while disruption of normal PLZF function is implicated in the development of APL. To clarify the function of PLZF in cell growth and survival, we used an inducible PLZF cell line in a microarray analysis to identify the target genes repressed by PLZF. One prominent gene identified was c-myc. The array analysis demonstrated that repression of c-myc by PLZF led to a reduction in c-myc-activated transcripts and an increase in c-myc-repressed transcripts. Regulation of c-myc by PLZF was shown to be both direct and reversible. An interaction between PLZF and the c-myc promoter could be detected both in vitro and in vivo. PLZF repressed the wild-type c-myc promoter in a reporter assay, dependent on the integrity of the binding site identified in vitro. PLZF binding in vivo was coincident with a decrease in RNA polymerase occupation of the c-myc promoter, indicating that repression occurred via a reduction in the initiation of transcription. Finally, expression of c-myc reversed the cell cycle arrest induced by PLZF. These data suggest that PLZF expression maintains a cell in a quiescent state by repressing c-myc expression and preventing cell cycle progression. Loss of this repression through the translocation that occurs in t(11;17) would have serious consequences for cell growth control.

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