We recently reported that ectopic expression of miR-128b together with miR-221, two of the miRNAs downregulated in MLL-AF4 ALL, restores glucocorticoid resistance through downregulation of the MLL-AF4 chimeric fusion proteins MLL-AF4 and AF4-MLL that are generated by chromosomal translocation t(4;11).
These results demonstrate that down-regulation of miR-128b and miR-221 is implicated in glucocorticoid resistance and that restoration of their levels is a potentially promising therapeutic in MLL-AF4 ALL.