Menin as a hub controlling mixed lineage leukemia

Abstract

Mixed lineage leukemia (MLL) fusion protein (FP)‐induced acute leukemia is highly aggressive and often refractory to therapy. Recent progress in the field has unraveled novel mechanisms and targets to combat this disease. Menin, a nuclear protein, interacts with wild‐type (WT) MLL, MLL‐FPs, and other partners such as the chromatin‐associated protein LEDGF and the transcription factor C‐Myb to promote leukemogenesis. The newly solved co‐crystal structure illustrating the menin–MLL interaction, coupled with the role of menin in recruiting both WT MLL and MLL‐FPs to target genes, highlights menin as a scaffold protein and a central hub controlling this type of leukemia. The menin/WT MLL/MLL‐FP hub may also cooperate with several signaling pathways, including Wnt, GSK3, and bromodomain‐containing Brd4‐related pathways to sustain MLL‐FP‐induced leukemogenesis, revealing new therapeutic targets to improve the treatment of MLL‐FP leukemias. In MLL fusion protein‐induced leukemias, menin is a central hub due to its role in recruiting WT MLL and MLL‐FPs to target genes. Menin also links C‐Myb/LEDGF to the MLL N‐terminus, underscoring menin's central role. Targeting menin may be especially effective due to its hub role in MLL fusion leukemias.