MI-2 (Menin-MLL Inhibitor) is a potent menin-MLL interaction inhibitor with an IC50 value of 446 ± 28 nM.
Menin is an oncogenic cofactor in leukemic transformations which could bind to the N-terminal fragment of MLL existed in all MLL fusion proteins. Menin is a highly specific and direct binding partner of MLL and MLL fusion proteins which is essential for regulation of their target genes. Disruption of the menin-MLL protein interaction abrogates oncogenic properties of MLL fusion proteins and blocks the development of acute leukemia [2].
In vitro: In HEK293 cells, MI-2 accessed the protein target menin-MLL and effectively inhibited the menin-MLL-AF9 interaction. MI-2 effectively blocked cell proliferation, and induced cell apoptosis in human MLL leukemia cell lines harboring different MLL translocations MLL-AF9 and MLL-ENL, with the GI50 value of about 5 μM for MI-2. MI-2 showed little effect on the cell growth of E2A-HLF transduced BMC with the GI50 of > 50 μM. MI-2 specifically reduced the immortalization potential of cells transformed with MLL fusion oncoproteins by downregulating the expression of target genes required for MLL fusion protein oncogenic activity [1].
In vivo: After 7 days treatment with MI-2, MLL-AF9 transformed BMC showed great morphology changes and the expression of CD11b was greatly increased [1].
References:
[1]. Grembecka J, He S, Shi A, et al. Menin-MLL inhibitors reverse oncogenic activity of MLL fusion proteins in leukemia[J]. Nature chemical biology, 2012, 8(3): 277-284.
[2]. Borkin D, He S, Miao H, et al. Pharmacologic inhibition of the Menin-MLL interaction blocks progression of MLL leukemia in vivo[J]. Cancer Cell, 2015, 27(4): 589-602.