A New Molecular Mechanism Underlying the Antitumor Effect of DNA Methylation Inhibitors via an Antiviral Immune Response

2017 ◽  
pp. 227-242 ◽  
Author(s):  
Y. Saito ◽  
T. Nakaoka ◽  
H. Saito
Keyword(s):  
Dna Methylation ◽  
Immune Response ◽  
Molecular Mechanism ◽  
Antitumor Effect ◽  
Antiviral Immune Response ◽  
Dna Methylation Inhibitors

scholarly journals Aberrant DNA Methylation in Cholangiocarcinoma

2017 ◽  
Author(s):  
Toshiaki Nakaoka ◽  
Yoshimasa Saito ◽  
Hidetsugu Saito
Keyword(s):  
Dna Methylation ◽  
Immune Response ◽  
Tumor Suppressor ◽  
Tumor Suppressor Genes ◽  
Ampulla Of Vater ◽  
Endogenous Retroviruses ◽  
Epigenetic Therapy ◽  
Suppressor Genes ◽  
Aberrant Dna Methylation ◽  
Dna Methylation Inhibitors

Cholangiocarcinoma is an epithelial malignancy arising in the region between the intrahepatic bile ducts and the ampulla of Vater at the distal end of the common bile duct. The effect of current chemotherapy regimens against cholangiocarcinoma is limited, and the prognosis of patients with cholangiocarcinoma is poor. Aberrant DNA methylation and histone modification induce silencing of tumor suppressor genes and chromosomal instability during carcinogenesis. Studies have shown that the tumor suppressor genes and microRNAs (miRNAs) including MLH1, p14, p16, DAPK, miR-370 and miR-376c are frequently methylated in cholangiocarcinoma. Silencing of these tumor suppressor genes and miRNAs plays critical roles in the initiation and progression of cholangiocarcinoma. In addition, recent studies have demonstrated that DNA methylation inhibitors induce expression of endogenous retroviruses and exert the anti-tumor effect of via an anti-viral immune response. Aberrant DNA methylation of tumor suppressor genes and miRNAs could be a powerful biomarker for diagnosis and treatment of cholangiocarcinoma. Epigenetic therapy with DNA methylation inhibitors hold considerable promise for the treatment of cholangiocarcinoma through re-activation of tumor suppressor genes and miRNAs as well as induction of an anti-viral immune response.

scholarly journals Protective Effects of Lactoferrin against SARS-CoV-2 Infection In Vitro

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 328 ◽  
Author(s):  
Claudio Salaris ◽  
Melania Scarpa ◽  
Marina Elli ◽  
Alice Bertolini ◽  
Simone Guglielmetti ◽  
...  
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Plaque Assay ◽  
Immune Response Gene ◽  
Intestinal Epithelial ◽  
Antiviral Immune Response ◽  
Qrt Pcr ◽  
Anti Inflammatory

SARS-CoV-2 is a newly emerging virus that currently lacks curative treatments. Lactoferrin (LF) is a naturally occurring non-toxic glycoprotein with broad-spectrum antiviral, immunomodulatory and anti-inflammatory effects. In this study, we assessed the potential of LF in the prevention of SARS-CoV-2 infection in vitro. Antiviral immune response gene expression was analyzed by qRT-PCR in uninfected Caco-2 intestinal epithelial cells treated with LF. An infection assay for SARS-CoV-2 was performed in Caco-2 cells treated or not with LF. SARS-CoV-2 titer was determined by qRT-PCR, plaque assay and immunostaining. Inflammatory and anti-inflammatory cytokine production was determined by qRT-PCR. LF significantly induced the expression of IFNA1, IFNB1, TLR3, TLR7, IRF3, IRF7 and MAVS genes. Furthermore, LF partially inhibited SARS-CoV-2 infection and replication in Caco-2 intestinal epithelial cells. Our in vitro data support LF as an immune modulator of the antiviral immune response with moderate effects against SARS-CoV-2 infection.

scholarly journals Role of Virally-Encoded Deubiquitinating Enzymes in Regulation of the Virus Life Cycle

2021 ◽  
Vol 22 (9) ◽  
pp. 4438
Author(s):  
Jessica Proulx ◽  
Kathleen Borgmann ◽  
In-Woo Park
Keyword(s):  
Immune Response ◽  
Life Cycle ◽  
Deubiquitinating Enzyme ◽  
Deubiquitinating Enzymes ◽  
Antiviral Immune Response ◽  
Cellular Processes ◽  
Virus Life Cycle ◽  
Infected Cells ◽  
Dependent Processes

The ubiquitin (Ub) proteasome system (UPS) plays a pivotal role in regulation of numerous cellular processes, including innate and adaptive immune responses that are essential for restriction of the virus life cycle in the infected cells. Deubiquitination by the deubiquitinating enzyme, deubiquitinase (DUB), is a reversible molecular process to remove Ub or Ub chains from the target proteins. Deubiquitination is an integral strategy within the UPS in regulating survival and proliferation of the infecting virus and the virus-invaded cells. Many viruses in the infected cells are reported to encode viral DUB, and these vial DUBs actively disrupt cellular Ub-dependent processes to suppress host antiviral immune response, enhancing virus replication and thus proliferation. This review surveys the types of DUBs encoded by different viruses and their molecular processes for how the infecting viruses take advantage of the DUB system to evade the host immune response and expedite their replication.

PS02.176: LINE-1 METHYLATION LEVEL AND LOCAL IMMUNE RESPONSE IN ESOPHAGEAL CANCER

2018 ◽  
Vol 31 (Supplement_1) ◽  
pp. 172-172
Author(s):  
Yoshifumi Baba ◽  
Taisuke Yagi ◽  
Yuki Kiyozumi ◽  
Yukiharu Hiyoshi ◽  
Masaaki Iwatsuki ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Immune Response ◽  
Esophageal Cancer ◽  
Methylation Level ◽  
Cpg Island ◽  
Surrogate Marker ◽  
Esophageal Tumor ◽  
Local Immune Response ◽  
Dna Hypomethylation ◽  
Response Status

Abstract Background In cancer cells, DNA methylation may be altered in two principle ways; global DNA hypomethylation and site-specific CpG island promoter hypermethylation. Since Long interspersed element-1 (LINE-1 or L1; a repetitive DNA retrotransposon) constitutes a substantial portion (approximately 17%) of the human genome, the extent of LINE-1 methylation is regarded as a surrogate marker of global DNA methylation. In previous studies, we demonstrated that LINE-1 hypomethylation was strongly associated with a poor prognosis in esophageal cancer, supporting its potential role as a prognostic marker (Ann Surg 2012). We also found that LINE-1-hypomethylated tumors showed highly frequent genomic gains at various loci containing candidate oncogenes such as CDK6 (Clin Cancer Res 2014). Given that immunotherapy, as represented by PD-1/PD-L1-targeting antibodies, has increasingly gained attention as a novel treatment strategy for esophageal cancer, better understanding of local immune response status in esophageal cancer is important. The aim of this study is to evaluate the relationship between LINE-1 methylation level and local immune response in esophageal cancer. Methods Using a non-biased database of 305 curatively resected esophageal cancers, we evaluated PD-L1 expression and TIL status (CD8 expression) by immunohistochemical analysis (Ann Surg 2017). Results TIL positivity was significantly correlated with longer overall survival (log-rank P < 0.0001). TIL-negative cases demonstrated significantly lower LINE-1 methylation level compared with TIL-positive cases (P = 0.012). This finding certainly supports that LINE-1 methylation level may influence the local immune response status. Conclusion PD-L1 expression was not related with LINE-1 methylation level. Further investigations in this field would provide deeper insights into esophageal tumor immunology and assist the development of new therapeutic strategies against esophageal cancer. Disclosure All authors have declared no conflicts of interest.

scholarly journals ADIPONECTIN PROMOTES COXSACKIEVIRUS B3 MYOCARDITIS BY SUPPRESSING THE ACUTE ANTIVIRAL IMMUNE RESPONSE

2013 ◽  
Vol 61 (10) ◽  
pp. E1263
Author(s):  
Carsten Skurk ◽  
Alexander Jenke ◽  
Moritz Becher ◽  
Alice Weithäuser ◽  
Karin Klingel ◽  
...  
Keyword(s):  
Immune Response ◽  
Coxsackievirus B3 ◽  
Antiviral Immune Response

scholarly journals PGC7 suppresses TET3 for protecting DNA methylation

2013 ◽  
Vol 42 (5) ◽  
pp. 2893-2905 ◽  
Author(s):  
Chunjing Bian ◽  
Xiaochun Yu
Keyword(s):  
Dna Methylation ◽  
Molecular Mechanism ◽  
Biological Process ◽  
Cpg Islands ◽  
Binding Motifs ◽  
Genome Wide Analysis ◽  
Dna Motif ◽  
Genome Wide

Abstract Ten-eleven translocation (TET) family enzymes convert 5-methylcytosine to 5-hydroxylmethylcytosine. However, the molecular mechanism that regulates this biological process is not clear. Here, we show the evidence that PGC7 (also known as Dppa3 or Stella) interacts with TET2 and TET3 both in vitro and in vivo to suppress the enzymatic activity of TET2 and TET3. Moreover, lacking PGC7 induces the loss of DNA methylation at imprinting loci. Genome-wide analysis of PGC7 reveals a consensus DNA motif that is recognized by PGC7. The CpG islands surrounding the PGC7-binding motifs are hypermethylated. Taken together, our study demonstrates a molecular mechanism by which PGC7 protects DNA methylation from TET family enzyme-dependent oxidation.

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