Epigenetic modifications are important early events during carcinogenesis. In particular, hypermethylation of CpG islands in the promoter region of tumor suppressor genes is a well-known mechanism of gene silencing that contributes to cancer development and progression. Tissue factor pathway inhibitor 2 (TFPI-2) is a tumor suppressor involved in invasiveness inhibition. Although TFPI-2 transcriptional silencing, through promoter hypermethylation, has been widely reported in several human malignancies, it has never been explored in lymphoma. In the present study TFPI-2 methylation and gene expression have been investigated in canine Diffuse Large B-cell lymphomas (cDLBCL). The methylation level of 23 CpGs located within the TFPI-2 promoter was investigated by bisulfite-specific PCR and next generation amplicon deep sequencing (GS Junior 454, Roche) in 22 cDLBCLs and 9 controls. For the same specimens, TFPI-2 gene expression was assessed by means of Real-time RT-PCR. Sequence analysis clearly demonstrated that TFPI2 is frequently hypermethylated in cDLBCL. Hypermethylation of the TFPI-2 promoter was found in 77% of DLBCLs (17 out of 22) and in one normal lymph node. Globally, dogs with DLBCL showed a mean methylation level significantly increased compared to controls (p<0.01) and analysis of hypermethylation by site identified 19 loci out of 23 (82%) with mean methylation levels from 2- to 120-fold higher in cDLBCL. Gene expression analysis confirmed a significant down-regulation of TFPI-2 (p<0.05) in DLBCLs compared with normal lymph nodes, suggesting that TFPI-2 hypermethylation negatively regulates its transcription. In addition, a significant positive correlation (p<0.01) was found between TFPI-2 methylation levels and age providing the first indication of age-associated epigenetic modifications in canine DLBCL. To conclude, our findings demonstrated that epigenetic dysregulation of TFPI-2, leading to its reduced expression, is frequently detected in canine DLBCL. In the next future, the aberrant TFPI-2 promoter hypermethylation may be considered in association with prognosis and therapy.
Epigenetic silencing of TFPI-2 in canine diffuse large B-cell lymphoma / S. Ferraresso, S. Bresolin, A. Aricò, S. Comazzi, M.E. Gelain, F. Riondato, L. Bargelloni, L. Marconato, G. Te Kronnie, L. Aresu. - In: PLOS ONE. - ISSN 1932-6203. - 9:4(2014 Apr), pp. e92707.1-e92707.10.
|Titolo:||Epigenetic silencing of TFPI-2 in canine diffuse large B-cell lymphoma|
|Parole Chiave:||Animals; DNA Methylation; DNA, Neoplasm; Dogs; Female; Glycoproteins; Humans; Male; Neoplasm Proteins; Promoter Regions, Genetic; Dog Diseases; Gene Silencing; Lymphoma, Large B-Cell, Diffuse; Agricultural and Biological Sciences (all); Biochemistry, Genetics and Molecular Biology (all); Medicine (all)|
|Settore Scientifico Disciplinare:||Settore VET/03 - Patologia Generale e Anatomia Patologica Veterinaria|
|Data di pubblicazione:||apr-2014|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1371/journal.pone.0092707|
|Appare nelle tipologie:||01 - Articolo su periodico|