The molecular impact of miR-326 in acute lymphoblastic leukemia and its cross talk with P53

MiR-326 downregulation is strongly associated with multidrug resistance (MDR) and has been identified as an adverse prognostic biomarker for pediatric acute lymphoblastic leukemia (pALL). The choice to study miR-326 as a tumor suppressor in cancer biology, particularly its regulation of apoptosis, drug resistance, and stemness, stems from its strong association with MDR and potential as a therapeutic target in pALL. The current study aimed to investigate, for the first time, the molecular mechanisms underlying the role of miR-326 in ALL, using Gene Ontology annotation network and multilayer network analysis. Our findings revealed that miR-326 exhibits a multifunctional anti-tumor behavior, affecting various aspects of drug resistance, stemness, and apoptosis in cancer, particularly in the context of ALL. Quantitative real-time PCR demonstrated downregulation of the ABC transporter mRNAs ABCC1 and ABCB1 but not ABCA3 in B-ALL cells transfected with miR-326 mimic, as confirmed by bioinformatic data. Western blot analysis showed a possible cross talk between miR-326 and P53 through the upregulation of Mdm2 and P53 proteins. The heightened functional activity of P53 was subsequently validated through the observed augmentation in levels of P21 and CCND1, alongside the evident disruption in the expression levels of Bcl-2, Bcl-xl, and Bax genes. Subsequently, the ceRNA network between miR-326 and LncRNAs was exhibited and the impact of exogenous miR-326 on the expression levels of its molecular sponges, H19 and SNHG1 was examined using RT-qPCR. Future studies will explore the potential impact of miR-326 on its targets, and how this may influence the development of novel therapeutic strategies for ALL.