scholarly journals Measles virus nucleoprotein induces cell-proliferation arrest and apoptosis through NTAIL–NR and NCORE–FcγRIIB1 interactions, respectively

2005 ◽  
Vol 86 (6) ◽  
pp. 1771-1784 ◽  
Author(s):  
D. Laine ◽  
J. M. Bourhis ◽  
S. Longhi ◽  
M. Flacher ◽  
L. Cassard ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Measles Virus ◽  
Caspase 3 ◽  
Inhibitory Effect ◽  
Cell Growth Arrest ◽  
Surface Receptors ◽  
Extracellular Compartment ◽  
Infected Cells ◽  
Nucleoprotein N

Measles virus (MV) nucleoprotein (N) is a cytosolic protein that is released into the extracellular compartment after apoptosis and/or secondary necrosis of MV-infected cells in vitro. Thus, MV-N becomes accessible to inhibitory cell-surface receptors: FcγRIIB and an uncharacterized nucleoprotein receptor (NR). MV-N is composed of two domains: NCORE (aa 1–400) and NTAIL (aa 401–525). To assess the contribution of MV-N domains and of these two receptors in suppression of cell proliferation, a human melanoma HT144 cell line expressing (HT144IIB1) or lacking FcγRIIB1 was used as a model. Specific and exclusive NCORE–FcγRIIB1 and NTAIL–NR interactions were shown. Moreover, NTAIL binding to human NR predominantly led to suppression of cell proliferation by arresting cells in the G0/G1 phases of the cell cycle, rather than to apoptosis. NCORE binding to HT144IIB1 cells primarily triggered caspase-3 activation, in contrast to HT144IIB1/IC− cells lacking the FcγRIIB1 intra-cytoplasmic tail, thus demonstrating the specific inhibitory effect of the NCORE–FcγRIIB1 interaction. MV-N- and NCORE-mediated apoptosis through FcγRIIB1 was inhibited by the pan-caspase inhibitor zVAD-FMK, indicating that apoptosis was dependent on caspase activation. By using NTAIL deletion proteins, it was also shown that the region of NTAIL responsible for binding to human NR and for cell growth arrest maps to one of the three conserved boxes (Box1, aa 401–420) found in N of Morbilliviruses. This work unveils novel mechanisms by which distinct domains of MV-N may display different immunosuppressive activities, thus contributing to our comprehension of the immunosuppressive state associated with MV infection. Finally, MV-N domains may be good tools to target tumour cell proliferation and/or apoptosis.

scholarly journals 12-Epi-Napelline Inhibits Leukemia Cell Proliferation via the PI3K/AKT Signaling Pathway In Vitro and In Vivo

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jia Han ◽  
Wei Hou ◽  
Bi-qing Cai ◽  
Fan Zhang ◽  
Jian-cai Tang
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Caspase 3 ◽  
Animal Experiments ◽  
Leukemia Cell ◽  
Tumor Model ◽  
Inhibitory Effect ◽  
Induced Apoptosis

This study aimed to investigate the inhibitory effect of 12-epi-napelline on leukemia cells and its possible mechanisms. The inhibitory effects of 12-epi-napelline on K-562 and HL-60 cells were evaluated using the CCK-8 assay, cell cycle arrest and apoptosis were detected by flow cytometry, and the expression of related proteins was measured by western blot. A K-562 tumor model was established to evaluate the antitumor effect of 12-epi-napelline in vivo. A reduction in leukemia cell viability was observed after treatment with 12-epi-napelline. It was determined that the cell cycle was arrested in the G0/G1 phase, and the cell apoptosis rate was increased. Moreover, caspase-3 and Bcl-2 were downregulated, whereas cleaved caspase-3 and caspase-9 were upregulated. Further study revealed that 12-epi-napelline could suppress the expression of PI3K, AKT, p-AKT, and mTOR. Insulin-like growth factor 1 (IGF-1) attenuated 12-epi-napelline-induced apoptosis and ameliorated the repression of PI3K, AKT, p-AKT, and mTOR by 12-epi-napelline. Animal experiments clearly showed that 12-epi-napelline inhibited tumor growth. In conclusion, 12-epi-napelline restrained leukemia cell proliferation by suppressing the PI3K/AKT/mTOR pathway in vitro and in vivo.

The P-MAPA immunomodulator partially prevents apoptosis induced by Zika virus infection in THP-1 cells

2020 ◽  
Vol 21 ◽  
Author(s):  
Morganna C. Lima ◽  
Elisa A. N. Azevedo ◽  
Clarice N. L. de Morais ◽  
Larissa I. O. de Sousa ◽  
Bruno M. Carvalho ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Virus Infection ◽  
Virus Replication ◽  
Zika Virus ◽  
Mammalian Cells ◽  
Caspase 3 ◽  
Neurological Complications ◽  
Zika Virus Infection

Background: Zika virus is an emerging arbovirus of global importance. ZIKV infection is associated with a range of neurological complications such as the Congenital Zika Syndrome and Guillain Barré Syndrome. Despite the magnitude of recent outbreaks, there is no specific therapy to prevent or to alleviate disease pathology. Objective: To investigate the role of P-MAPA immunomodulator in Zika-infected THP-1 cells. Methods: THP-1 cells were subjected at Zika virus infection (Multiplicity of Infection = 0.5) followed by treatment with P-MAPA for until 96 hours post-infection. After that, the cell death was analyzed by annexin+/ PI+ and caspase 3/ 7+ staining by flow cytometry. In addition, the virus replication and cell proliferation were accessed by RT-qPCR and Ki67 staining, respectively. Results: We demonstrate that P-MAPA in vitro treatment significantly reduces Zika virus-induced cell death and caspase-3/7 activation on THP-1 infected cells, albeit it has no role in virus replication and cell proliferation. Conclusions: Our study reveals that P-MAPA seems to be a satisfactory alternative to inhibits the effects of Zika virus infection in mammalian cells.

scholarly journals BRD4 PROTAC degrader ARV-825 inhibits T-cell acute lymphoblastic leukemia by targeting 'Undruggable' Myc-pathway genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Acute Lymphoblastic Leukemia ◽  
Caspase 3 ◽  
Lymphoblastic Leukemia ◽  
Rna Seq ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Bet Protein

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.

scholarly journals RBFOX3 Regulates the Chemosensitivity of Cancer Cells to 5-Fluorouracil via the PI3K/AKT, EMT and Cytochrome-C/Caspase Pathways

2018 ◽  
Vol 46 (4) ◽  
pp. 1365-1380 ◽  
Author(s):  
Tianze Liu ◽  
Xiaojun Wu ◽  
Yizhuo Li ◽  
Wenjing Lu ◽  
Fufu Zheng ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cytochrome C ◽  
Rna Binding ◽  
Inhibitory Effect ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model ◽  
Hcc Cells

Background/Aims: RBFOX3, an RNA-binding fox protein, plays an important role in the differentiation of neuronal development, but its role in the chemosensitivity of hepatocellular carcinoma (HCC) to 5-FU is unknown. Methods: In this study, we examined the biological functions of RBFOX3 and its effect on the chemosensitivity of HCC cells to 5-FU in vitro and in a mouse xenograft model. Results: RBFOX3 was found to have elevated expression in HCC cell lines and tissue samples, and its knockdown inhibited HCC cell proliferation. Moreover, knockdown of RBFOX3 improved the inhibitory effect of 5-fluorouracil (5-FU) on cell proliferation, migration and invasion, and enhanced the apoptosis induced by 5-FU. However, overexpression of RBFOX3 reduced the inhibitory effect of 5-fluorouracil (5-FU) on cell proliferation, migration and invasion, and decreased the apoptosis induced by 5-FU. We further elucidated that RBFOX3 knockdown synergized with 5-FU to inhibit the growth and invasion of HCC cells through PI3K/AKT and epithelial-mesenchymal transition (EMT) signaling, and promote apoptosis by activating the cytochrome-c/caspase signaling pathway. Finally, we validated that RBFOX3 regulated 5-FU-mediated cytotoxicity in HCC in mouse xenograft models. Conclusions: The findings from this study indicate that RBFOX3 regulates the chemosensitivity of HCC to 5-FU in vitro and in vivo. Therefore, targeting RBFOX3 may improve the inhibition of HCC growth and progression by 5-FU, and provide a novel potential therapeutic strategy for HCC.

Beauvericin Inhibits the Growth of U251 Glioma Cells and Promotes Apoptosis In Vitro

2020 ◽  
Vol 14 (5) ◽  
pp. 639-644
Author(s):  
Liming Hu ◽  
Tianyi Zhao ◽  
Jia Wang ◽  
Renguang Wang ◽  
Hongshi Bu ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Glioma Cells ◽  
Inhibitory Effect ◽  
U251 Cell ◽  
Western Blot Assay ◽  
Expression Levels ◽  
Signal Transduction Proteins

To elucidated the inhibitory effect of beauvericin (BEA) on glioma cells and its possible molecular mechanism, in this study, the MTT assay was performed to observed the effect of BEA on cell proliferation, the flow cytometry was used to measure its protective effect on cell apoptosis, and the Western Blot assay was performed to test the expression levels of signal transduction proteins. In the results, the concentration of BEA was 0.5 μmoL/L in the drug group, indicating that it has obvious protect effect to the U251 cells. The apoptosis rates of BEA, Cis and BEA+Cis groups, compared with the U251 group, were 2.93, 3.71 and 5.0 times higher respectively. In addition, the expression levels of Cyclin D1, E, B and Bcl-2 in BEA group were 75, 69, 78 and 67% of that in the U251 group, while Bax and cleaved caspase-3 were twice as much as that in the U251 group. In conclusion, beauvericin can inhibit U251 cell apoptosis and the possible mechanism is to reduce the expression of Cyclin D1, B, E and Bcl-2, while the levels of Bax and cleaved Caspase-3 increased. Thus, BEA has a broad application prospect in the treatment of glioma.

scholarly journals Measles Virus-Induced Immunosuppression In Vitro Is Independent of Complex Glycosylation of Viral Glycoproteins and of Hemifusion

2000 ◽  
Vol 74 (16) ◽  
pp. 7548-7553 ◽  
Author(s):  
Armin Weidmann ◽  
Christian Fischer ◽  
Shinji Ohgimoto ◽  
Claudia Rüth ◽  
Volker ter Meulen ◽  
...  
Keyword(s):  
Measles Virus ◽  
Human Lymphocytes ◽  
Lymphoid Cells ◽  
Oxygen Intermediates ◽  
Inhibitory Peptides ◽  
Viral Particles ◽  
Infected Cells ◽  
Necessary And Sufficient ◽  
Cellular Fusion

ABSTRACT Expression of the measles virus (MV) F/H complex on the surface of viral particles, infected cells, or cells transfected to express these proteins (presenter cells [PC]) is necessary and sufficient to induce proliferative arrest in both human and rodent lymphoid cells (responder cells [RC]). This inhibition was found to occur independent of apoptosis and soluble mediators excluded by a pore size filter of 200 nm released from either PC or RC. We now show that reactive oxygen intermediates which might be released by RC or PC also do not contribute to MV-induced immunosuppression in vitro. Using an inhibitor of Golgi-resident mannosidases (deoxymannojirimycin), we found that complex glycosylation of the F and H proteins is not required for the induction of proliferative arrest of RC. As revealed by our previous studies, proteolytic cleavage of the MV F protein precursor into its F1 and F2 subunits, but not of F/H-mediated cellular fusion, was found to be required, since fusion-inhibitory peptides such as Z-d-Phe-l-Phe-Gly (Z-fFG) did not interfere with the induction of proliferative inhibition. We now show that Z-fFG inhibits cellular fusion at the stage of hemifusion by preventing lipid mixing of the outer membrane layer. These results provide strong evidence for a receptor-mediated signal elicited by the MV F/H complex which can be uncoupled from its fusogenic activity is required for the induction of proliferative arrest of human lymphocytes.

scholarly journals Cleavage Map and Proteolytic Processing of the Murine Norovirus Nonstructural Polyprotein in Infected Cells

2006 ◽  
Vol 80 (16) ◽  
pp. 7816-7831 ◽  
Author(s):  
Stanislav V. Sosnovtsev ◽  
Gaël Belliot ◽  
Kyeong-OK Chang ◽  
Victor G. Prikhodko ◽  
Larissa B. Thackray ◽  
...  
Keyword(s):  
Cell Culture ◽  
Caspase 3 ◽  
Proteolytic Processing ◽  
Site Directed Mutagenesis ◽  
Cleavage Sites ◽  
Murine Norovirus ◽  
Permissive Cell ◽  
Additional Processing ◽  
Infected Cells

ABSTRACT Murine norovirus (MNV) is presently the only member of the genus Norovirus in the Caliciviridae that can be propagated in cell culture. The goal of this study was to elucidate the proteolytic processing strategy of MNV during an authentic replication cycle in cells. A proteolytic cleavage map of the ORF1 polyprotein was generated, and the virus-encoded 3C-like (3CL) proteinase (Pro) mediated cleavage at five dipeptide cleavage sites, 341E/G342, Q705/N706, 870E/G871, 994E/A995, and 1177Q/G1178, that defined the borders of six proteins with the gene order p38.3 (Nterm)-p39.6 (NTPase)-p18.6-p14.3 (VPg)-p19.2 (Pro)-p57.5 (Pol). Bacterially expressed MNV 3CL Pro was sufficient to mediate trans cleavage of the ORF1 polyprotein containing the mutagenized Pro sequence into products identical to those observed during cotranslational processing of the authentic ORF1 polyprotein in vitro and to those observed in MNV-infected cells. Immunoprecipitation and Western blot analysis of proteins produced in virus-infected cells demonstrated efficient cleavage of the proteinase-polymerase precursor. Evidence for additional processing of the Nterm protein in MNV-infected cells by caspase 3 was obtained, and Nterm sequences 118DRPD121 and 128DAMD131 were mapped as caspase 3 cleavage sites by site-directed mutagenesis. The availability of the MNV nonstructural polyprotein cleavage map in concert with a permissive cell culture system should facilitate studies of norovirus replication.

Sign in / Sign up

Export Citation Format

Share Document