MYCMI-6 (NSC354961) is a potent and selective endogenous MYC:MAX protein interactions inhibitor. MYCMI-6 blocks MYC-driven transcription and binds selectively to the MYC bHLHZip domain with a Kd of 1.6 μM. MYCMI-6 inhibits tumor cell growth in a MYC-dependent manner (IC50<0.5 μM). MYCMI-6 is not cytotoxic to normal human cells. MYCMI-6 induces apoptosis[1].

MYCMI-6 (NSC354961) (6.25 μM; 48 hours) selectively suppresses MYC-driven tumor cell growth with high efficacy[1].MYCMI-6 significantly inhibits growth of Burkitt's lymphoma cells (Mutu, Daudi and ST486) - another classical example of a MYC-driven tumor, having translocations of MYC to one of the immunoglobulin loci - in a dose-dependent manner with an average GI50 of 0.5 μM. Treatment of MCF7 cells with the MYCMI-6 for 24 hours significantly decreased MYC:MAX isPLA signals to 7%. Titration showed an IC50 for inhibition of MYC:MAX of less than 1.5 μM for MYCMI-6 by isPLA. MYCMI-6 inhibits the MYC:MAX heterodimer formation with an IC50 of 3.8 μM. MYCMI-6 efficiently inhibits anchorage-independent growth of MYCN-amplified neuroblastoma cells with GI50 values of <0.4 μM[1]. Cell Viability Assay[1] Cell Line: MYCN-amplified neuroblastoma cells (IMR-32, Kelly and SK-N-DZ), MYCN-non-amplified neuroblastoma cells (SK-N-F1, SK-N-AS and SK-N-RA)

MYCMI-6 (20 mg/kg; i.p.; daily for 1-2 weeks) induces massive apoptosis and reduces tumor cell proliferation, tumor microvasculature density and MYC:MAX interaction in a MYC-dependent xenograft tumor model[1]. Animal Model: 6-8 weeks old athymic nude mice (bearing MYCN-amplified SK-N-DZ neuroblastoma cells)[1]

[1]. Castell A, et al. A selective high affinity MYC-binding compound inhibits MYC:MAX interaction and MYC-dependent tumor cell proliferation. Sci Rep. 2018 Jul 3;8(1):10064.