mTOR/HDAC6-IN-1 is an effective dual inhibitor of histone deacetylase (HDAC6) and mammalian rapamycin (mTOR). The IC50 values for HDAC6 and mTOR are 56 nM and 133.7 nM respectively. MTOR/HDAC6-IN-1 can significantly induce autophagy and apoptosis and inhibit migration. MTOR/HDAC6-IN-1 has potential in the study of triple negative breast cancer (TNBC).

HDAC6:56 nM, mTOR:133.7 nM

mTOR/HDAC6-IN-1, identified as compound 10g, displays moderate anti-proliferative effects on MDA-MB-231, MDA-MB-436, and MDA-MB-468 cell lines, exhibiting IC50 values of 8.4 μM, 10.6 μM, and 14.3 μM respectively after 48 hours of exposure. This compound, at a concentration of 10 μM over 6 hours, significantly enhances the thermal stability of HDAC6 in MDA-MB-231 cells, indicating a selective inhibition of HDAC6. Furthermore, at concentrations ranging from 2.5 to 10 μM over a period of two weeks, it effectively prevents the clonal formation of MDA-MB-231 cells. Additionally, at dosages of 2.5, 5, and 10 μM for 48 hours, it triggers significant autophagy characterized by increased LC3 puncta in the same cell line. At higher concentrations of 5, 10, and 20 μM, mTOR/HDAC6-IN-1 induces apoptosis in a dose-responsive manner in MDA-MB-231 cells, simultaneously increasing Bax expression, decreasing Bcl-2 levels, and facilitating the cleavage of PARP alongside caspase 8 and caspase 3. This compound also curtails cell migration in a dose-dependent manner at concentrations of 5, 10, and 20 μM over 48 hours, by reducing MMP-2 expression and enhancing E-cadherin levels. This range of effects underscores the compound's potential as a therapeutic agent by affecting cell proliferation, survival, and migration pathways in cancer cells.