International Journal of Preventive Medicine (Int J Prev Med)2008-78021182020092723322332ENApplied Physiology Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, IsfahanApplied Physiology Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan & School of Medicine, Isfahan University of Medical Sciences, IsfahanApplied Physiology Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan & Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan20200927<p><strong>Background</strong>: Previous studies show that aberrant synthesis of Hyaluronan accelerates tumor<br />growth, angiogenesis, and metastasis. The fibroblasts are probably responsible for most of the<br />hyaluronic acid (HA) accumulation in tumor microenvironment after radiotherapy. Our goal is to<br />investigate and compare radiation and lactate effects on HA levels in supernatant and exosome<br />isolated from supernatant of primary mouse fibroblast cell culture. <strong>Methods</strong>: Fibroblast cells<br />were prepared from skin of C57BL6 mouse. These cells were divided into three groups (no<br />treatment, cells treated with 10 mM ammonium lactate, and irradiated cells). Then supernatant<br />was harvested from FBS‑free culture media after 48 h. Exosomes were purified by differential<br />centrifugation (300 × g for 10 min, 2000 × g for 30 min, 16500 g for 30 min) and were pelleted<br />by ultracentrifugation (150,000 × g for 180 min). Size of exosomes was determined using<br />a Zetasizer. HA concentration measured using a HA ELISA Kit. Data were analyzed using<br />one‑way ANOVA.</p><p><strong>Results</strong>: There was a significant increase in HA‑coated exosomes isolated<br />from supernatants of irradiated cells compared to untreated cell and cells treated with 10 mM<br />ammonium lactate (P &lt; 0.001). As well, there was a significant increase in the HA concentration<br />in the supernatants of cells treated with 10 mM ammonium lactate relative to untreated cells and<br />irradiated cells (P &lt; 0.05).</p><p><strong>Conclusions</strong>: It seems that routine radiation therapy leads to massive<br />shedding of HA‑coated exosomes by normal fibroblast cells and thus exosomes‑HA may contribute<br />to tumor promotion and induce of the premetastatic niche.<br /><br /></p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/2332http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2332/717718174