scholarly journals Immortalization-Upregulated Protein Promotes Pancreatic Cancer Progression By Regulating NPM1/FHL1-Mediated Cell-Cycle-Checkpoint Protein Activity

2021 ◽  
Author(s):  
Qiankun Luo ◽  
Yanfeng Pan ◽  
Qiang Fu ◽  
Xu Zhang ◽  
Shuai Zhou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cancer Progression ◽  
Cell Cycle Checkpoint ◽  
The Cancer Genome Atlas ◽  
Ductal Adenocarcinoma ◽  
Cycle Arrest ◽  
Cycle Checkpoint

Abstract Immortalization-upregulated protein (IMUP) plays a vital role in cell proliferation and tumor progression. However, its role in pancreatic ductal adenocarcinoma (PDAC) remains unclear. Here, we select IMUP as an alternative gene based on GeneChip analysis of clinical PDAC tissues and transcriptome data from The Cancer Genome Atlas. IMUP expression is upregulated in PDAC tumor tissues. Moreover, high IMUP expression correlates with poor prognosis, while IMUP depletion inhibits PDAC cell proliferation and colony formation capacity in vitro, and decreases xenograft tumor growth in vivo. IMUP downregulation leads to cell-cycle arrest in the S phase. IMUP Knockdown increases the expression of four-and-a-half LIM domain protein 1 (FHL1), which regulates the phosphorylation of cell division cycle 25A (CDC25A) by cycle checkpoint kinase 1 (CHK1) and promotes cytoplasmic distribution of CDC25A by interaction with 14-3-3ξ. Furthermore, FHL1 knockdown restores the effects induced by IMUP depletion. liquid chromatography tandem mass spectrometry and immunoprecipitation analysis further show that IMUP interacts directly with nucleophosmin (NPM1) and enhances its stability. DNA methylation sequencing shows that FHL1 promoter methylation decreases when IMUP is downregulated. Overexpression of NPM1 can increase the methylation level of FHL1, thereby decreasing its expression. Our study provides a novel perspective on IMUP/NPM1/FHL1-mediated cell-cycle arrest by regulating CDC25A phosphorylation in PDAC. These findings may provide a new therapeutic target for PDAC.

scholarly journals Aberrant Expression of Nucleostemin Activates p53 and Induces Cell Cycle Arrest via Inhibition of MDM2

2008 ◽  
Vol 28 (13) ◽  
pp. 4365-4376 ◽  
Author(s):  
Mu-Shui Dai ◽  
Xiao-Xin Sun ◽  
Hua Lu
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Ribosomal Proteins ◽  
Cell Cycle Checkpoint ◽  
Aberrant Expression ◽  
Cycle Arrest ◽  
Reduce Cell Proliferation ◽  
Cycle Checkpoint ◽  
Dependent Cell

ABSTRACT The nucleolar protein nucleostemin (NS) is essential for cell proliferation and early embryogenesis. Both depletion and overexpression of NS reduce cell proliferation. However, the mechanisms underlying this regulation are still unclear. Here, we show that NS regulates p53 activity through the inhibition of MDM2. NS binds to the central acidic domain of MDM2 and inhibits MDM2-mediated p53 ubiquitylation and degradation. Consequently, ectopic overexpression of NS activates p53, induces G1 cell cycle arrest, and inhibits cell proliferation. Interestingly, the knockdown of NS by small interfering RNA also activates p53 and induces G1 arrest. These effects require the ribosomal proteins L5 and L11, since the depletion of NS enhanced their interactions with MDM2 and the knockdown of L5 or L11 abrogated the NS depletion-induced p53 activation and cell cycle arrest. These results suggest that a p53-dependent cell cycle checkpoint monitors changes of cellular NS levels via the impediment of MDM2 function.

scholarly journals Cyclin Dependent Kinase-1 (CDK-1) Inhibition as a Novel Therapeutic Strategy against Pancreatic Ductal Adenocarcinoma (PDAC)

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4389
Author(s):  
Rosa Wijnen ◽  
Camilla Pecoraro ◽  
Daniela Carbone ◽  
Hamid Fiuji ◽  
Amir Avan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Radiation Treatment ◽  
Cell Cycle Checkpoint ◽  
Ductal Adenocarcinoma ◽  
M Cell ◽  
Combination Treatments ◽  
Cycle Arrest ◽  
M Phase ◽  
Cycle Checkpoint

The role of CDK1 in PDAC onset and development is two-fold. Firstly, since CDK1 activity regulates the G2/M cell cycle checkpoint, overexpression of CDK1 can lead to progression into mitosis even in cells with DNA damage, a potentially tumorigenic process. Secondly, CDK1 overexpression leads to the stimulation of a range of proteins that induce stem cell properties, which can contribute to the development of cancer stem cells (CSCs). CSCs promote tumor-initiation and metastasis and play a crucial role in the development of PDAC. Targeting CDK1 showed promising results for PDAC treatment in different preclinical models, where CDK1 inhibition induced cell cycle arrest in the G2/M phase and led to induction of apoptosis. Next to this, PDAC CSCs are uniquely sensitive to CDK1 inhibition. In addition, targeting of CDK1 has shown potential for combination therapy with both ionizing radiation treatment and conventional chemotherapy, through sensitizing tumor cells and reducing resistance to these treatments. To conclude, CDK1 inhibition induces G2/M cell cycle arrest, stimulates apoptosis, and specifically targets CSCs, which makes it a promising treatment for PDAC. Screening of patients for CDK1 overexpression and further research into combination treatments is essential for optimizing this novel targeted therapy.

scholarly journals CCT Chaperonin Complex Is Required for the Biogenesis of Functional Plk1

2005 ◽  
Vol 25 (12) ◽  
pp. 4993-5010 ◽  
Author(s):  
Xiaoqi Liu ◽  
Chin-Yo Lin ◽  
Ming Lei ◽  
Shi Yan ◽  
Tianhua Zhou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Mammalian Cells ◽  
Active Form ◽  
Cycle Arrest ◽  
Cdc2 Activity ◽  
Partial Depletion

ABSTRACT Experiments from several different organisms have demonstrated that polo-like kinases are involved in many aspects of mitosis and cytokinesis. Here, we provide evidence to show that Plk1 associates with chaperonin-containing TCP1 complex (CCT) both in vitro and in vivo. Silencing of CCT by use of RNA interference (RNAi) in mammalian cells inhibits cell proliferation, decreases cell viability, causes cell cycle arrest with 4N DNA content, and leads to apoptosis. Depletion of CCT in well-synchronized HeLa cells causes cell cycle arrest at G2, as demonstrated by a low mitotic index and Cdc2 activity. Complete depletion of Plk1 in well-synchronized cells also leads to G2 block, suggesting that misfolded Plk1 might be responsible for the failure of CCT-depleted cells to enter mitosis. Moreover, partial depletion of CCT or Plk1 leads to mitotic arrest. Finally, the CCT-depleted cells reenter the cell cycle upon reintroduction of the purified constitutively active form of Plk1, indicating that Plk1 might be a CCT substrate.

scholarly journals Dysregulation of miR-23b-5p promotes cell proliferation via targeting FOXM1 in hepatocellular carcinoma

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xinchen Yang ◽  
Shikun Yang ◽  
Jinhua Song ◽  
Wenjie Yang ◽  
Yang Ji ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Tumor Development ◽  
Loss Of Function ◽  
Cycle Arrest ◽  
Cell Proliferation Inhibition

AbstractGrowing evidence demonstrates that MicroRNAs (miRNAs) play an essential role in contributing to tumor development and progression. However, the underlying role and mechanisms of miR-23b-5p in hepatocellular carcinoma (HCC) formation remain unclear. Our study showed that miR-23b-5p was downregulated in the HCC tissues and cell lines, and lower expression of miR-23b-5p was associated with more severe tumor size and poorer survival. Gain- or loss-of-function assays demonstrated that miR-23b-5p induced G0/G1 cell cycle arrest and inhibited cell proliferation both in vitro and in vivo. qRT-PCR, western blot and luciferase assays verified that Mammalian transcription factor Forkhead Box M1 (FOXM1), upregulated in HCC specimens, was negatively correlated with miR-23b-5p expression and acted as a direct downstream target of miR-23b-5p. In addition, miR-23b-5p could regulate cyclin D1 and c-MYC expression by directly targeting FOXM1. Further study revealed that restoration of FOXM1 neutralized the cell cycle arrest and cell proliferation inhibition caused by miR-23b-5p. Taken together, our findings suggest that miR-23b-5p acted as a tumor suppressor role in HCC progression by targeting FOXM1 and may serve as a potential novel biomarker for HCC diagnosis and prognosis.

Knockdown of HOXC6 inhibits glioma cell proliferation and induces cell cycle arrest by targeting WIF-1 in vitro and vivo

2018 ◽  
Vol 214 (11) ◽  
pp. 1818-1824 ◽  
Author(s):  
Teng-feng Yan ◽  
Miao-jing Wu ◽  
Bing Xiao ◽  
Qing Hu ◽  
Yang-Hua Fan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Glioma Cell ◽  
Cycle Arrest ◽  
Glioma Cell Proliferation

Spermidine/spermine N1-acetyltransferase overexpression in kidney epithelial cells disrupts polyamine homeostasis, leads to DNA damage, and causes G2 arrest

2007 ◽  
Vol 292 (3) ◽  
pp. C1204-C1215 ◽  
Author(s):  
Kamyar Zahedi ◽  
John J. Bissler ◽  
Zhaohui Wang ◽  
Anuradha Josyula ◽  
Lu Lu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Damage ◽  
Dna Repair ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Dna Lesions ◽  
Cell Cycle Checkpoint ◽  
Cycle Checkpoint

Expression of spermidine/spermine N1-acetyltransferase (SSAT) increases in kidneys subjected to ischemia-reperfusion injury (IRI). Increased expression of SSAT in vitro leads to alterations in cellular polyamine content, depletion of cofactors and precursors of polyamine synthesis, and reduced cell proliferation. In our model system, a >28-fold increase in SSAT levels in HEK-293 cells leads to depletion of polyamines and elevation in the enzymatic activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, suggestive of a compensatory reaction to increased polyamine catabolism. Increased expression of SSAT also led to DNA damage and G2 arrest. The increased DNA damage was primarily due to the depletion of polyamines. Other factors such as increased production of H2O2 due to polyamine oxidase activity may play a secondary role in the induction of DNA lesions. In response to DNA damage the ATM/ATR → Chk1/2 DNA repair and cell cycle checkpoint pathways were activated, mediating the G2 arrest in SSAT-expressing cells. In addition, the activation of ERK1 and ERK2, which play integral roles in the G2/M transition, is impaired in cells expressing SSAT. These results indicate that the disruption of polyamine homeostasis due to enhanced SSAT activity leads to DNA damage and reduced cell proliferation via activation of DNA repair and cell cycle checkpoint and disruption of Raf → MEK → ERK pathways. We propose that in kidneys subjected to IRI, one mechanism through which increased expression of SSAT may cause cellular injury and organ damage is through induction of DNA damage and the disruption of cell cycle.

ID: 96: CINOBUFOTALIN AS A NOVEL AGENT TO INHIBIT IN-VITRO EPITHELIAL OVARIAN CANCER CELL PROLIFERATION, MIGRATION AND INVASION

2016 ◽  
Vol 64 (4) ◽  
pp. 948.2-949
Author(s):  
AC McDowell ◽  
TC McCormick ◽  
TJ Kuehl ◽  
MN Uddin ◽  
SH Afroze ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cancer Cell ◽  
Cell Function ◽  
Migration And Invasion ◽  
Apoptotic Signaling ◽  
Cycle Arrest

ObjectiveCinobufotalin (CINO), a cardiotonic steroid (CTS) or bufadienolide, is extracted from the skin secretions of giant toads and is utilized in traditional Chinese medicine (Chan Su). CINO has been used as a cardiotonic, diuretic and a hemostatic agent. Our lab is familiar with CINO and has shown it to inhibit cytotrophoblast cells function. Recently, it has been shown that CINO also inhibits the lung cancer cell function, and has been further implicated in other disease processes. In the present study, we propose to pursue this potential application of CINO using ovarian tumor cell line SK-OV-3.Study DesignWe evaluated the in-vitro effect of CINO on ovarian cancer cell line SK-OV-3. Cells were treated with 0.1, 1, 5, and 10 µM CINO. Cell proliferation was measured using a CellTiter Assay (Promega), which is a colorimetric method for determining the number of viable cells. Cell migration was measured using a CytoSelect Assay (Cell Biolabs). Cell invasion was measured using a FluoroBlok Assay (BD). Cell viability was measure using a CellTiter Assay (Promega). Cell cycle progression was evaluated by a Cell Cycle Phase Determination Kit (Cayman Chemical) and apoptosis was evaluated by an Apoptotic Blebs Assay Kit (Cayman Chemical). Cell cycle arrest and apoptotic signaling was determined by fluorescence-activated cell sorting (FACS) analysis.ResultsCINO at ≥0.5 µM inhibited SKOV-3 cell proliferation, migration, and invasion (p<0.05). There was a higher (p<0.05) percentage of S phase cells in groups treated with CINO at 0.5 µM. CINO at ≥0.5 µM down regulated expression of PCNA and caused cell death.ConclusionThis data demonstrates that CINO impairs SK-OV-3 cell function via cell cycle arrest and apoptotic signaling. These findings demonstrate the complex nature of this compound. Not only is CINO directly modulating the actions of the Na/K ATPase through classic mechanism of cardiotonic steroids, but is also directly influencing the nuclear expression of proteins involved in cell cycle progression and DNA repair. Additional investigational studies looking into the molecular pathways involved in altering cell cycle and entry into apoptosis are warranted.In conclusion, we have shown CINO to impair SK-OV3 cell function via cell cycle arrest and apoptotic signaling and suggest that CINO might be further investigated as a novel anti-ovarian cancer agent.

Role of Different C/EBPα Mutations in AML Transformation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1343-1343
Author(s):  
Oscar Quintana-Bustamante ◽  
S. Lan-Lan Smith ◽  
Jude Fitzgibbon ◽  
Dominique Bonnet
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Myeloid Differentiation ◽  
Granulocytic Differentiation ◽  
Self Renewal ◽  
Cycle Arrest

Abstract Acute Myeloid Leukemia (AML) is characterized by an abnormal hematopoietic differentiation and uncontrolled cell proliferation. Mutations in several transcription factors (TFs) have been implicated in the development of leukemia. One of these TFs is CCAAT/enhancer-binding protein-α (C/EBPα). In normal hematopoiesis, C/EBPα plays a central role to coordinate myeloid differentiation and growth arrest. C/EBPα is mutated in approximately 9% of AML; these mutations take place either in C or N terminal domains of the protein, although there are several familial cases of AML where both types of mutations have been found. We use C and/or N terminal C/EBPα mutations from one case of sporadic AML to investigate the role of each mutation in leukemic transformation (Smith et al., 2004, N Engl J Med 351, 2403–2407). Human lineage negative (Lin-) umbilical cord blood were transduced with lentiviral vectors carrying the wild type C/EBPα (WT), N terminal mutated C/EBPα (N-ter) or N and C terminal mutated (NC-ter) C/EBPα cloned from this sporadic case of AML. We observed differences in proliferation of transduced Lin- in vitro: WT C/EBPα expression resulted in G0 cell cycle arrest causing a progressive extinction of the transduced cells overtime; N-ter cells showed a higher proliferative advantage over untransduced cells. The NC-ter CEBPα cells like untransduced cells kept their levels throughout culture. Furthermore, when induced into myeloid differentiation in vitro, WT C/EBPα cells were mainly inducing fully mature granulocytes whereas N-ter C/EBPα was not able to induce terminal granulocytic differentiation; in contrast NC-ter C/EBPα did not increase myeloid differentiation. Additionally, their ability to form Colony Forming Units (CFUs) in primary, secondary and tertiary replating was also tested: WT transduced cells gave rise to few primary CFUs; contrary, N and NC-ter could generate both primary and secondary CFUs, but only NC-ter cells were able to produce CFUs in tertiary replating, indicating its ability to maintain undifferentiated hematopoietic progenitors in vitro. These results were confirmed using Long-Term Culture Initiating Cells (LTC-IC) where the NC-ter mutated cells showed the highest LTC-IC after 5 weeks. Finally, in vivo transplantation in NOD/SCID/β2mnull indicated that NC-ter mutated cells engraft better than WT and N-ter 8 week post- transplant. Serial transplantation experiments are underway to evaluate their self-renewal capacity. Our results confirmed some known functions of WT C/EBPα in human hematopoiesis, such as inducing myeloid differentiation and cell cycle arrest. On the other hand, we showed new functions for the C/EBPα mutants. The N-ter C/EBPα mutation caused an increase in cell proliferation and blockage of terminal granulocytic differentiation, whereas the NC-ter C/EBPα mutation increased the self-renewal capacity of progenitor/stem cells without having an influence on myeloid differentiation. This work provides further insight into the mechanisms by which different C/EBPα mutations induce AML.

scholarly journals In Vivo and In Vitro Effects of Tracheloside on Colorectal Cancer Cell Proliferation and Metastasis

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 513
Author(s):  
Min-Kyoung Shin ◽  
Yong-Deok Jeon ◽  
Seung-Heon Hong ◽  
Sa-Haeng Kang ◽  
Ji-Ye Kee ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Oxidant Stress ◽  
Mesenchymal Transition ◽  
Cycle Arrest

Recent research suggests a relationship between cancer progression and oxidative mechanisms. Among the phenolic compounds such as tracheloside (TCS) are a major bioactive compound that can combat oxidant stress-related chronic diseases and that also displays anti-tumor activity. Although TCS can inhibit mammalian carcinoma, its effects on colorectal cancer (CRC) have not been clarified. The purpose of this study was to investigate the effects of TCS on the proliferation of CRC cells, the metastasis of CT26 cells, and the molecular mechanisms related to TCS in vitro and in vivo. A cell viability assay showed that TCS inhibited the proliferation of CRC cells. TCS-treated CT26 cells were associated with the upregulation of p16 as well as the downregulation of cyclin D1 and CDK4 in cell cycle arrest. In addition, TCS induced apoptosis of CT26 cells through mitochondria-mediated apoptosis and regulation of the Bcl-2 family. Expression of epithelial–mesenchymal transition (EMT) markers was regulated by TCS treatment in CT26 cells. TCS significantly inhibited the lung metastasis of CT26 cells in a mouse model. These results suggest that TCS, by inducing cell cycle arrest and apoptosis through its anti-oxidant properties, is a novel therapeutic agent that inhibits metastatic phenotypes of murine CRC cells.

Sign in / Sign up

Export Citation Format

Share Document