S-Me-DM1

S-methyl DM1 is a thiomethyl derivative of Maytansine. S-methyl DM1 binds to tubulin with a Kd of 0.93 μM and inhibts microtubule polymerization. S-methyl DM1 potently suppresses microtubule dynamic instability and has anticancer effects[1][2].

Research Areas >> Cancer

Signaling Pathways >> Cell Cycle/DNA Damage >> Microtubule/Tubulin

Signaling Pathways >> Cytoskeleton >> Microtubule/Tubulin

Kd: 0.93 μM (Tubulin)[1]

S-methyl DM1 is the primary cellular or liver metabolite of antibody-maytansinoid conjugates prepared with thiol-containing maytansinoids DM1[1]. The half-maximal concentration for inhibition of microtubule assembly for for S-methyl DM1 is 4 μM. At 100 nM S-methyl-DM1 (84%) suppresses dynamic instability more strongly than Maytansine (45%). Tritiated S-methyl-DM1 bound to 37 high-affinity sites per microtubule (Kd of 0.1 μM)[1]. The concentration dependence curves for the inhibition of cell proliferation by S-methyl DM1 is sigmoidal in shape in MCF7 cells. Minimal inhibition occurred at 200 pM S-methyl DM1, and inhibition is maximal at 3 nM. S-methyl DM1 (IC50 of 330 pM) is slightly more potent than Maytansine (IC50 of 710 pM)[2]. S-methyl DM1 induces maxima of 80% accumulation of cells in G2/M as compared with only 30% in controls in MCF7 cells[2].

[1]. Lopus M, et al. Maytansine and cellular metabolites of antibody-maytansinoid conjugates strongly suppress microtubule dynamics by binding to microtubules. Mol Cancer Ther. 2010 Oct;9(10):2689-99.

[2]. Oroudjev E, et al. Maytansinoid-antibody conjugates induce mitotic arrest by suppressing microtubule dynamic instability. Mol Cancer Ther. 2010 Oct;9(10):2700-13.