چكيده لاتين
Abstract
Among various types of cancer, leukemia is a common hematologic malignancy with serious consequences and is the most prevalent cancer in children. Acute Lymphoblastic Leukemia (ALL) accounts for approximately 26% of all cancers in children under 15 years and 78% of hematologic cancers in this age group. This disease is characterized by uncontrolled proliferation of lymphoid precursors in the bone marrow, leading to impaired production of normal blood cells, weakened immune system, and clinical symptoms such as fever, pallor, organomegaly, recurrent infections, and fatigue. Based on clinical criteria, patients are classified into standard-risk and high-risk groups, which play a critical role in predicting treatment response.
Since long non-coding RNAs (lncRNAs) have recently been recognized as important regulators of gene expression at epigenetic, transcriptional, and post-transcriptional levels, and their dysregulation is associated with many cancers including leukemia, this study aimed to identify differentially expressed lncRNAs in ALL and evaluate their expression levels in patient samples.
In the bioinformatics phase, RNA-Seq data from peripheral blood mononuclear cells (PBMCs) of pediatric ALL patients were extracted from the TCGA database and analyzed using R software. Applying filters of adjusted p-value (padj) < 0.05 and log2 fold change (log2FC) > 1 or < −1, a total of 18,160 differentially expressed genes were identified, including 16,038 upregulated and 2,122 downregulated genes. Among the upregulated genes, 6,101 were lncRNAs.
Patient sampling was performed in collaboration with Seyed Al-Shohada (Omid) Hospital, Isfahan. The lncRNA KCNQ1OT1 was selected for laboratory validation due to its significant upregulation.
In the experimental phase, total RNA was extracted from peripheral blood samples of 36 pediatric ALL patients and 36 healthy adult controls using TRIzol reagent. Following cDNA synthesis, the expression level of KCNQ1OT1 was measured by RT-PCR. The results showed a significant increase in KCNQ1OT1 expression in ALL patients compared to healthy controls (p < 0.0001).
To further investigate the relationship between this increase and immune status, patients were divided into two subgroups based on white blood cell (WBC) counts. Both groups, with WBC below and above the normal range, showed significantly higher KCNQ1OT1 expression compared to controls (p < 0.0001 and p = 0.0105, respectively). These findings suggest that KCNQ1OT1 upregulation is associated with abnormal WBC status and may contribute to the pathogenesis of the disease. Therefore, KCNQ1OT1 could serve as a potential molecular biomarker for diagnosis and monitoring of ALL patients.
This study, by identifying and analyzing differentially expressed lncRNAs in ALL and validating KCNQ1OT1 expression, provides a foundation for developing new diagnostic and therapeutic approaches in this disease.
Keywords: Acute Lymphoblastic Leukemia, Hematology, Long Non-Coding RNA, Gene Expression, Bioinformatics
