scholarly journals Identification of aberrant cell cycle regulation in Epstein-Barr virus-associated nasopharyngeal carcinoma by cDNA microarray and gene set enrichment analysis

2009 ◽  
Vol 41 (5) ◽  
pp. 414-428 ◽  
Author(s):  
W. Zhang ◽  
Z. Zeng ◽  
Y. Zhou ◽  
W. Xiong ◽  
S. Fan ◽  
...  
2003 ◽  
Vol 77 (17) ◽  
pp. 9652-9661 ◽  
Author(s):  
Yoshihiro Izumiya ◽  
Su-Fang Lin ◽  
Thomas J. Ellison ◽  
Alon M. Levy ◽  
Greg L. Mayeur ◽  
...  

ABSTRACT In order to cope with hostile host environments, many viruses have developed strategies to perturb the cellular machinery to suit their replication needs. Some herpesvirus genes protect cells from undergoing apoptosis to prolong the lives of infected cells, while others, such as Epstein-Barr virus Zta, slow down the G1/S transition phase to allow ample opportunity for transcription and translation of viral genes before the onset of cellular genomic replication. In this study, we investigated whether Kaposi's sarcoma-associated herpesvirus (KSHV) K-bZIP, a homologue of the Epstein-Barr virus transcription factor BZLF1 (Zta), plays a role in cell cycle regulation. Here we show that K-bZIP physically associates with cyclin-CDK2 and downmodulates its kinase activity. The association can be detected in the natural environment of KSHV-infected cells without artificial overexpression of either component. With purified protein, it can be shown that the interaction between K-bZIP and cyclin-CDK2 is direct and that K-bZIP alone is sufficient to inhibit CDK2 activity. The interacting domain of K-bZIP has been mapped to the basic region. The result of these associations is a prolonged G1 phase, accompanied by the induction of p21 and p27 in a naturally infected B-cell line. Thus, in addition to the previously described transcription and genome replication functions, a new role of K-bZIP in KSHV replication is identified in this report.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Li Yin ◽  
Jing Wu ◽  
Jianfeng Wu ◽  
Jinjun Ye ◽  
Xuesong Jiang ◽  
...  

This study aims to evaluate the radiosensitization effect of nedaplatin on nasopharyngeal carcinoma (NPC) cell lines with different Epstein-Barr virus (EBV) status. Human NPC cell lines CNE-2 (EBV-negative) and C666 (EBV-positive) were treated with 0–100 μg/mL nedaplatin, and inhibitory effects on cell viability and IC50were calculated by MTS assay. We assessed changes in radiosensitivity of cells by MTS and colony formation assays, and detected the apoptosis index and changes in cell cycle by flow cytometry. MTS assay showed that nedaplatin caused significant cytotoxicity in CNE-2 and C666 cells in a time- and dose-dependent manner. After 24 h, nedaplatin inhibited growth of CNE-2 and C666 cells with IC50values of 34.32 and 63.69 μg/mL, respectively. Compared with radiation alone, nedaplatin enhanced the radiation effect on both cell lines. Nedaplatin markedly increased apoptosis and cell cycle arrest in G2/M phase. Nedaplatin radiosensitized human NPC cells CNE-2 and C666, with a significantly greater effect on the former. The mechanisms of radiosensitization include induction of apoptosis and enhancement of cell cycle arrest in G2/M phase.


2008 ◽  
Vol 32 (3) ◽  
pp. S39-S39
Author(s):  
Wen Ling Zhang ◽  
Zhao Yang Zeng ◽  
Wei Xiong ◽  
Yan Hong Zhou ◽  
Song Qing Fan ◽  
...  

2006 ◽  
Vol 92 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Caiwen Du ◽  
Bogui Wen ◽  
Derui Li ◽  
Yingcheng Lin ◽  
Yuwu Zheng ◽  
...  

Aims and Background It was documented that nasopharyngeal carcinoma (NPC) is associated with Epstein-Barr virus (EBV) and that EBV-encoded latent membrane protein-1 expression (LMP1) plays an important role in the pathogenesis of NPC. In preclinical studies, arsenic trioxide (As2O3) has been identified as a promising anticancer agent for treatment of NPC. The purpose of this study is to investigate if this agent can inhibit the expression of LMP1 and therefore lead to growth inhibition of NPC cells in vitro. Methods LMP1-positive NPC cells, HNE1-LMP1, were treated with 3 umol/L of As2O3 for 96 hours. The LMP1 protein expression and mRNA level in HNE1-LMP1 cells were determined by western blot, confocal immunofluorescence staining and semiquantitative reverse transcriptase reaction (RT-PCR). Apoptosis was determined by light microscopy and the TUNEL method. Alterations in the cell cycle distribution were also investigated by flow cytometry. MTT assay and colony formation assay were used to detect the proliferation of the cells. The LMP1-negative parental cell lines HNE1 and HNE2 were used as control in an attempt to elucidate the role of LMP1 in the anticancer effect of As2O3 on NPC cells. Results The expression of LMP1 at the protein and mRNA level was reduced after exposure to 3 umol/L As2O3. This dose of As2O3 significantly induced apoptosis and growth retardation of HNE1-LMP1 cells. In addition, more HNE1-LMP1 cells were induced to G0/G1 and G2/M arrest. The same dose of As2O3 had a moderate effect on HNE1 and HNE2 cells. Conclusion Arsenic trioxide can inhibit LMP1 expression and dictate apoptosis and alterations of cell cycle distribution as well as growth retardation. LMP1-positive NPC cells are more sensitive to As2O3 treatment than LMP1-negative NPC cells.


Author(s):  
R. Stephens ◽  
K. Traul ◽  
D. Woolf ◽  
P. Gaudreau

A number of antigens have been found associated with persistent EBV infections of lymphoblastoid cells. Identification and localization of these antigens were principally by immunofluorescence (IF) techniques using sera from patients with nasopharyngeal carcinoma (NPC), Burkitt lymphoma (BL), and infectious mononucleosis (IM). Our study was mainly with three of the EBV related antigens, a) virus capsid antigen (VCA), b) membrane antigen (MA), and c) early antigens (EA) using immunoperoxidase (IP) techniques with electron microscopy (EM) to elucidate the sites of reactivity with EBV and EBV infected cells.Prior to labeling with horseradish peroxidase (HRP), sera from NPC, IM, and BL cases were characterized for various reactivities by the indirect IF technique. Modifications of the direct IP procedure described by Shabo and the indirect IP procedure of Leduc were made to enhance penetration of the cells and preservation of antigen reactivity.


2020 ◽  
Vol 13 (3) ◽  
pp. 192-205 ◽  
Author(s):  
Fanghong Lei ◽  
Tongda Lei ◽  
Yun Huang ◽  
Mingxiu Yang ◽  
Mingchu Liao ◽  
...  

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. As a neoplastic disorder, NPC is a highly malignant squamous cell carcinoma that is derived from the nasopharyngeal epithelium. NPC is radiosensitive; radiotherapy or radiotherapy combining with chemotherapy are the main treatment strategies. However, both modalities are usually accompanied by complications and acquired resistance to radiotherapy is a significant impediment to effective NPC therapy. Therefore, there is an urgent need to discover effective radio-sensitization and radio-resistance biomarkers for NPC. Recent studies have shown that Epstein-Barr virus (EBV)-encoded products, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which share several common signaling pathways, can function in radio-related NPC cells or tissues. Understanding these interconnected regulatory networks will reveal the details of NPC radiation sensitivity and resistance. In this review, we discuss and summarize the specific molecular mechanisms of NPC radio-sensitization and radio-resistance, focusing on EBV-encoded products, miRNAs, lncRNAs and circRNAs. This will provide a foundation for the discovery of more accurate, effective and specific markers related to NPC radiotherapy. EBVencoded products, miRNAs, lncRNAs and circRNAs have emerged as crucial molecules mediating the radio-susceptibility of NPC. This understanding will improve the clinical application of markers and inform the development of novel therapeutics for NPC.


Sign in / Sign up

Export Citation Format

Share Document