Multiomics to investigate the mechanisms contributing to repression of PTPRC and SOCS2 in pediatric T‐ALL: Focus on miR‐363‐3p and promoter methylation

T‐cell acute lymphoblastic leukemia (T‐ALL) is a heterogeneous and aggressive malignancy arising from T‐cell precursors. MiRNAs are implicated in negative regulation of gene expression and when aberrantly expressed contribute to various cancer types, including T‐ALL. Previously we demonstrated the oncogenic potential of miR‐363‐3p overexpression in a subgroup of T‐ALL patients. Here, using combined proteomic and transcriptomic approaches, we show that miR‐363‐3p enhances cell growth of T‐ALL in vitro via inhibition of PTPRC and SOCS2, which are implicated in repression of the JAK–STAT pathway. We propose that overexpression of miR‐363‐3p is a novel mechanism potentially contributing to overactivation of JAK–STAT pathway. Additionally, by combining the transcriptomic and methylation data of T‐ALL patients, we show that promoter methylation may also contribute to downregulation of SOCS2 expression and thus potentially to JAK–STAT activation. In conclusion, we highlight aberrant miRNA expression and aberrant promoter methylation as mechanisms, alternative to mutations of JAK–STAT‐related genes, which might lead to the upregulation of JAK‐dependent signaling in T‐ALL.