Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 12 1 2018 01 05 49 56 EN Mohammad Kazemi Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. AND Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran. AND Medical Genetic Center of Genome, Isfahan University of Medical Sciences, Isfahan, Iran Farinaz Khosravian Medical Genetic Center of Genome, Isfahan University of Medical Sciences, Isfahan, Iran Amir Abbas Sameti Isfahan Dental Student Research Committee, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran Alireza Moafi Department of Pediatric Hematology, School of Medicine and Child Health Promotion Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Mohammad Reza Merasi Department of Epidemiology and Biostatistics, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran Mansour Salehi Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. AND Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran. AND Medical Genetic Center of Genome, Isfahan University of Medical Sciences, Isfahan, Iran Majid Nejati Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, Iran Mohaddeseh Behjati Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran 2016 11 26 2018 01 02 Background: Acute leukemia is a common pediatric cancer. Novel strategies for treatment of acute leukemia have been developed, but treatment resistance has remained as the most problematic issue. It is hypothesized that the HO-1 gene up-regulation is responsible for tumor resistance to chemotherapy or radiotherapy-induced apoptosis. HO-1 expression levels have been related to (GT)n microsatellite polymorphisms in the location of its promoter.This study designed to compare allelic frequencies of (GT)n microsatellite polymorphisms in HO-1 gene between acute leukemia patients and healthy controls. Indeed, 3-year disease-free survival was also evaluated. Materials and Methods: The study included 63 acute leukemia patients and 70 healthy infants. We used patient’s medical records to collect data regarding the post-chemotherapy survival. The number of GT repeats in HO-1 promoter was determined by an ABI 3100 sequencer. Results: The HO-1 GT repeats ranged from 14 to 34 with peaks at 27 repeats in both cases and controls. Children with longer alleles ((GT)n ≥ 27) had enhanced 3-year survival rate after treatment with chemotherapy or radiotherapy (P<0.05). Conclusion: Although no significant differences were observed between leukemia patients and controls regarding allelic frequency, we found elevated frequency of “LL” genotype in leukemia patients with good 3-year surveillance. Radiotherapy and chemotherapy might elevate the expression levels of HO-1 with subsequent increased resistance of leukemia patients to therapy.   https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/708 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/708/602