en زیست شناسی ملکولی Molecular Biology مقالات اصلی Original Article <div style="text-align: justify;"><strong>Background:</strong> The current study aims to investigate the relationship of miR-24 expression with plasma methotrexate (MTX) levels, therapy-related toxicities, and event-free survival (EFS) in Iranian pediatric acute lymphoblastic leukemia (ALL) patients.<br> <strong>Methods: </strong>The study included 74 ALL patients in consolidation phase and 41 healthy children. RNA was extracted from plasma, polyadenylated, and reverse transcribed. miR-24 expression was determined by quantitative polymerase chain reaction (qPCR). Plasma MTX concentrations were measured by high performance liquid chromatography (HPLC) 48 h after high-dose methotrexate (HD-MTX) injection. The diagnosis of ALL was further subclassified as B-ALL or T-ALL via flow cytometry.<br> <strong>Results:</strong> miR-24 expression was less in pediatric ALL patients than in the control group (p = 0.0038). Furthermore, downregulation of miR-24 was correlated with intermediate-to high-grade HD-MTX therapy toxicities (p = 0.025). Nevertheless, no statistically significant associations were seen between miR-24 levels and plasma MTX levels 48 h after HD-MTX administration (p > 0.05) or EFS in pediatric ALL patients (p > 0.05).<br> <strong>Conclusions:</strong> miR-24 expression may contribute to interindividual variability in response to intermediate-to high-grade HD-MTX therapy toxicities under Berlin Frankfurt Munster (BFM) treatment.</div> Acute Lymphoblastic Leukemia, Event Free Survival, Methotrexate, Mir, Toxicity 358 365 http://rbmb.net/browse.php?a_code=A-10-331-1&slc_lang=en&sid=1 Mohammad Ali Esmaili esmailionline@gmail.com 100319475328460017401 100319475328460017401 Yes Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran,Iran. Ahmad Kazemi a.kazemi32@gmail.com 100319475328460017402 100319475328460017402 No Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran,Iran. Farhad Zaker 100319475328460017403 100319475328460017403 No Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran,Iran. Mohammad Faranoush 100319475328460017404 100319475328460017404 No Pediatric Growth and Development Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran. & Mahak Hematology Oncology Research Center (MAHAK-HORC), Mahak Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mohammad Reza Rezvany rezvani.mr@iums.ac.ir 100319475328460017405 100319475328460017405 No Department of Hematology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran,Iran. & Pediatric Growth and Development Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran. & Department of Oncology-Pathology, Immune and Gene Therapy Lab, Cancer Center Karolinska (CCK), Karolinska University Hospital Solna and Karolinska Institute, Stockholm 17176, Sweden.