Radiation induced modulation of immunogenic genes in tumor cells is regulated by both histone deacetylases and DNA methyltransferases        
Yazarlar (3)
Prof. Dr. Ercan ÇAÇAN Tokat Gaziosmanpaşa Üniversitesi, Türkiye
Susanna Greer
Georgia State University, Amerika Birleşik Devletleri
Charlie Garnettbenson
Georgia State University, Amerika Birleşik Devletleri
Makale Türü Açık Erişim Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale
Dergi Adı International Journal of Oncology
Dergi ISSN 1019-6439 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI
Dergi Grubu Q4
Makale Dili İngilizce
Basım Tarihi 12-2015
Cilt No 47
Sayı 6
Sayfalar 2264 / 2275
DOI Numarası 10.3892/ijo.2015.3192
Özet
Radiation treatment is a pivotal therapy for several cancer types, including colorectal cancer. It has been shown that sublethal doses of radiation modulate gene expression, making tumor cells more susceptible to T-cell-mediated immune attack. We have recently shown that low dose radiation enhances expression of multiple death receptors (Fas, DR4 and DR5) and co-stimulatory molecules (4-1BBL and OX-40L) in colorectal cancer (CRC) cells; however, it is unclear how ionizing radiation (IR) enhances expression of these molecules mechanistically. In the present study, we elucidate the molecular mechanisms by which radiation controls expression of these molecules in CRC. Here we report that, enhanced expression of these genes following radiation treatment of CRC cells is due, in part, to changes in DNA methylation and histone acetylation. We observed that radiation (5 Gy) significantly increased histone acetylation at the promoter regions of 4-1BBL, Fas and DR5 but not OX-40L. However, radiation did not induce changes in the global levels of acetylated histone H3 suggesting specificity of IR-induced changes. Furthermore, evaluation of epigenetic controlling enzymes revealed that IR did not alter overall cellular levels of HDACs (HDAC1, HDAC2 or HDAC3) or DNMTs (DNMT1, DNMT3a, or DNMT3b). Instead, radiation decreased binding of HDAC2 and HDAC3 at the promoter regions of Fas and 4-1BBL, respectively. Radiation also resulted in reduced DNMT1 at both the Fas and 4-1BBL promoter regions but not a control gene. We conclude that single dose radiation can influence the expression of immune response relevant genes in colorectal tumor cells by altering the binding of epigenetic enzymes, and modulating histone acetylation, at specific gene promoters.
Anahtar Kelimeler
Co-stimulatory molecules | Death receptors | DNA methylation | Histone acetylation | Radiation