مقالات پذیرفته شده در نهمین کنگره بین المللی زیست پزشکی
Enhancing Daunorubicin Chemosensitivity in T-Cell Acute Lymphoblastic Leukemia Through p53R2 Gene Silencing via siRNA
Enhancing Daunorubicin Chemosensitivity in T-Cell Acute Lymphoblastic Leukemia Through p53R2 Gene Silencing via siRNA
Zahra Pooraskari,1,*Omid Kiani Ghalesardi,2Minoo Shahidi,3
1. Student Research Committee, Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran. 2. Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran. 3. Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran.
Introduction: T-cell acute lymphoblastic leukemia (T-ALL) is an extensive malignant neoplasm marked by increased recurrence rates, despite treatment protocols incorporating Daunorubicin. Daunorubicin is among the most often utilized anthracyclines for the treatment of ALL. Daunorubicin principally displays its anticancer effect through linking to DNA and blocking topoisomerase II, leading to DNA double-strand breaks (DSBs) and the consequent initiation of apoptosis. Daunorubicin induces severe toxicity, and resistance frequently develops via augmented DNA repair pathways. p53R2, a protein activated by p53, is a subunit of ribonucleotide reductase and is essential for providing deoxynucleoside triphosphates (dNTPs) required for the repair of DNA. Although p53R2 is linked to cancer progression, its specific function in T-ALL remains ambiguous. This study investigates the impact of p53R2 gene silencing on double-stranded DNA breaks and apoptosis in T-ALL cells (Jurkat) following daunorubicin therapy.
Methods: Transfection was executed with polyethyleneimine (PEI). Different experiments were used to analyze the cells after 24 hours. The MTT assay was used to assess the impact of p53R2 siRNA on the daunorubicin chemosensitivity and IC₅₀ values of T-ALL cells (Jurkat). The use of immunohistochemical labeling for γH2AX allowed for the identification of double-stranded DNA breaks. Additionally, Apoptosis was analyzed by flow cytometry (FACS Calibur), and the gene expression level of p53R2 mRNA was evaluated using quantitative real-time PCR. Data is shown as mean ± SD. The significance of the differences between the groups was assessed using Tukey's multiple comparison test. A p-value below 0.05 was considered significant. Statistical analyses were performed using GraphPad Prism (version 9).
Results: Our results indicated that the inhibition of p53R2 amplified the anti-proliferative efficacy of Daunorubicin in T-ALL cells via a synergistic mechanism. Daunorubicin's IC50 was reduced from 304.9 nM to 186.1 nM by p53R2 siRNA (P < 0.0001). Notably, p53R2 siRNA, when used with Daunorubicin, substantially elevated the incidence of DNA double-strand breaks in the Jurkat cells (P < 0.0001), although its application alone did not have this impact. Furthermore, the apoptosis induced by Daunorubicin in this cell line was significantly increased by the reduction of p53R2 (P < 0.0001). P53R2 siRNA substantially decreased gene expression levels (p<0.0001).
Conclusion: This study demonstrates that the anticancer efficacy of Daunorubicin on T-ALL cells can be enhanced by the inhibition of p53R2 by siRNA intervention. Furthermore, p53R2 siRNA decreases the necessary dosage of daunorubicin by reducing the IC50, hence reducing the drug's side effects. Thus, p53R2 siRNA could be a beneficial adjunct therapy for T-ALL in conjunction with Daunorubicin administration. Future research should concentrate on enhancing p53R2 siRNA delivery mechanisms and evaluating their therapeutic effectiveness and safety in preclinical T-ALL models. Such an approach may assist the creation of more successful and less hazardous combination regimens for leukemia therapy.