%0 Journal Article
%T Investigation of the interaction between the MIR-503 and CD40 genes in irradiated U937 cells
%A Guanghui Cheng
%A Shilong Sun
%A Zhanfeng Wang
%A Shunzi Jin
%J Radiation Oncology
%D 2012
%I BioMed Central
%R 10.1186/1748-717x-7-38
%X In the present study, we applied ionizing radiation with a dose of either 0.1 Gy or 5 Gy to irradiate U937 cells to confirm CD40 as a miR-503 target, which was identified using a bioimformatics tool. In high dose (5 Gy) ionizing-irradiated U937 cells, expression of miR-503 was up regulated while the expression of CD40 gene was down regulated. Using the transfection of the miR-503 gene into U937 cells and Luciferase assay, we confirmed that miR-503 suppressed the expression of CD40, and was a negtive regulator of CD40.To our knowledge, we are the first to describe involvement of miR-503 in radiobiological effect at a molecular level. This initial finding suggested the evidence that ionizing radiation could alter the expression of miR-503 and its target gene CD40, and may be very important to shed light on a possible mechanism regarding regulation of immune responses to irradiation.Radiotherapy is a common adjuvant therapy for the treatment of patients with cancer. However, the effect of radiation on the immune system always leads to some side-effects. When living cells are exposed to ionizing radiation (IR), a series of alterations will take place, including transformation, cell cycle distress, mutations and chromosomal aberrations, abnormality of DNA repair and apoptosis [1,2]. The final outcomes of IR-exposing cells are determined by the activation of nuclear pattern [3]. Among the IR-responsive genes, those for the CD40 pathway have been brought significant attention to the field of radiobiological effect because of their prominent role in orchestrating both the humoral immune response and the cellular immune response [4]. The interaction of CD40 on the surface of B lymphocytes with its ligand (CD45), which is predominantly expressed by activated T cells, is critical for the induction of adaptive immunity by promoting the proliferation and differentiation of B lymphocytes into immunoglobulin-producing plasma cells. The CD40-CD154 interactions are also important in
%K Radiation
%K miR-503
%K CD40
%U http://www.ro-journal.com/content/7/1/38