MT-44 is a highly selective and potent mTOR inhibitor with an IC50 value of 49.4 nM. It inhibits the proliferation, migration, and invasion of cancer cells. MT-44 induces apoptosis (apoptosis) and reactive oxygen species (ROS) production, leading to G2/M phase arrest. Additionally, it activates the cGAS/STING pathway. MT-44 is applicable in cancer research, including studies on triple-negative breast cancer.

MT-44 exhibits potent antiproliferative activity against TNBC cells MDA-MB-231 and MDA-MB-468, with IC 50 values of 66.5 nM and 148.2 nM, respectively. It inhibits the migration of MDA-MB-231 cells in a dose-dependent manner at concentrations of 0.25-1.0 μM over 12-48 hours and induces G2/M phase arrest. At concentrations between 0.05-0.5 μM, MT-44 significantly suppresses colony formation and invasion of MDA-MB-231 cells. Furthermore, within the range of 0.5-2.0 μM over 24 hours, it induces apoptosis and autophagy in MDA-MB-231 cells, accompanied by increased ROS accumulation. Additionally, MT-44 downregulates the phosphorylation levels of p-P70S6K, p-Akt, and p-4EBP1, while upregulating phosphorylated proteins in the cGAS/STING pathway within these cells.

MT-44, administered intravenously at a dose of 10-20 mg/kg every three days for a duration of 15 days, significantly inhibits tumor growth in the female BALB/c nude mouse model with MDA-MB-231 xenografts.