Expression and Activity of Dysregulated miRNAs in T-ALL Development and Progression.

Objectives: T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological disease caused by genetic abnormalities that manifest during the development of T-cell precursors, encompassing 15% of pediatric and 25% of adult ALL cases. While T-ALL and its heterogeneous genomic landscape has been well-characterized by establishing different subtypes and risk stratification for patients, the expression and activity of microRNAs (miRNAs) in T-ALL have not been investigated as extensively as cytogenetic and genomic abnormalities. miRNAs are prospective biomarkers that can be critical in improving diagnostic measures for T-ALL, expanding risk categorizations of patients for select therapies, and as target candidates for interventional treatments. Certain miRNAs have been found to be dysregulated as a result of mechanisms underlying T-ALL pathophysiology, including aberrant signaling pathways and epigenetics. Through the implementation of more robust bioinformatics such as miRNA target prediction tools, next-generation sequencing, and standard molecular techniques, recent research has underscored the significant contribution of miRNAs toward the development and progression of T-ALL by altering canonical signaling pathways associated with T-ALL such as NOTCH1, mTOR, and PI3K/AKT. In this review, we summarize the recent findings surrounding the expression and activity of dysregulated miRNAs and how they contribute to the onset and course of disease in T-ALL. As dysregulated miRNAs have been shown to elicit positive and negative responses, the dual effects of miRNAs demand additional research to elucidate miRNAs for target treatments in addition to profiling T-ALL further as a malignant disease.