Investigation of miRNA-34a and miRNA-521 expression levels in radiotherapy applications in patients with prostate cancer

In prostate canser, radiotherapy has therapeutic effect and increase treatment efficacy and thus the survival rate. However radio-resistant tumors may relapse and metastases. In cancer cells, some genes effected by radiation has direct effects on results of radiotherapy. MicroRNAs (miRNAs) are the molecules which regulate some process related with internal and external stresses. It has been showed that radiation resulted in some changes on synthesis of miRNAs and so, cellular responses in tumor cells. In the literature, although there are some information about changes of miRNA profiles in prostate cancer cell lines, there are very limited number of human studies. Our aim was to investigate expression levels of miR-34a and miR-521in patients with prostate cancer, before and after radiation therapy. 35 patients who admitted to Radiation Oncology Department for prostat cancer radiotherapy were included in this study. Blood samples for the miRNAs were obtained before and after initation of radioterapy. miR-34a and miR-521expressions were analyzed by using quantitative reverse-transcription polymerase chain reaction (qRT-PZR). We found that PSA, fPSA leukocyte count, hemoglobin, hematocrit, neutrophil, lymphocyte and PCT values decreased while miR-34a, miR-521 expression levels and MCV values increased in the group after radiotherapy. In conclusion, expression of miRNAs such as miR-34a and miR-521 effected by radiotherapy in patients with prostat cancer showing that they might be related with treatment efficacy of radiotherapy of cancer patients.