MicroRNA expression profile of human thymus populations corresponding to 8 sequential T-cell developmental stages isolated from 3 independent pediatric thymus samples.

ABSTRACT: T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy arising from the neoplastic transformation of immature T cells during their development in the thymus. Deciphering the developmental programs whose dysregulation leads to T-ALL pathogenesis is critical for the development of novel targeted therapies, which remain an urgent unmet need for the treatment of this disease. MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of numerous physiological processes and cancer. However, the specific role of miRNAs in human T-cell development and T-ALL pathogenesis remains largely unexplored. In this study, we comprehensively evaluated miRNA expression profiles across human T-cell development by microarray analysis and identified a dynamic expression pattern of miR-16-2, which is upregulated across early pre-T cell proliferative stages up to the resting state of immature thymocytes immediately preceding TCR expression, and decreased thereafter. We confirmed the coordinated regulation of miR-15b expression, consistent with the reported clustered genomic location of both miRNAs. Notably, functional studies identified the miR-15b/16-2 cluster as a negative regulator of early thymocyte proliferation, and showed that overexpression of miR-15b/16-2 in T-ALL cells impaired leukemic growth in vitro and tumor progression in patient-derived xenotransplantation assays. Mechanistically, miR-15b/16-2 expression represses the genes encoding BCL-2 and CYCLIN D3, leading to T-ALL apoptosis and cell cycle dysregulation, with an accumulation of G0-phase cells and a defective transition to the G2/M phase. Overall, these findings support a novel function for miR-15b/16-2 as tumor suppressors in T-ALL, highlighting their role as promising targets for T-ALL therapy.

ORGANISM(S): Homo sapiens

PROVIDER: GSE299842 | GEO | 2025/07/15

REPOSITORIES: GEO