PDE1-IN-6 (compound 6c) functions as a highly selective PDE1 inhibitor, exhibiting an IC 50 value of 7.5 nM. It notably inhibits proliferation and induces apoptosis in acute myelogenous leukemia cells [1].

PDE1-IN-6 (compound 6c) at concentrations of 10 and 20 μM over 48 hours, induces apoptosis in U937 and ML-1 cells [1]. In the same conditions, it downregulates the expression of the proteins caspase-3, 7, 9, PARP, Bcl-2, and Bcl-xl, while increasing the expression of their cleaved forms in these cells [1]. Apoptosis Analysis [1] involved cell lines U937 and ML-1 with concentrations set at 10, 20 μM and an incubation period of 48 hours, confirming induced apoptosis. Western Blot Analysis [1] also using U937 and ML-1 cell lines, at 10, 20 μM for 48 hours, showed reduced expression of caspase-3, 7, 9, PARP, Bcl-2, and Bcl-xl proteins, alongside an increase in their cleaved caspase-3, 7, 9 forms.