ISCK03 is a selective SCF/c-Kit inhibitor.

Pretreatment with ISCK03 dose-dependently inhibits SCF-induced c-kit phosphorylation and p44/42 ERK (MAPK) phosphorylation, key components of SCF/c-kit signaling, without affecting HGF-induced phosphorylation of the same ERK proteins. As a specific tyrosine kinase inhibitor of KIT, ISCK03 effectively suppresses the survival of CCDC26-KD cells in low-serum environments, demonstrating dose-dependent sensitivity. While significantly impacting KD cells, reducing their survival to levels comparable with non-KD cells, ISCK03 shows minimal effects on the growth of control K562 and KD clone 3–4 cells in high-serum conditions.

Administering ISCK03 orally causes a dose-dependent depigmentation of newly regrown hair, a process that reverses upon discontinuing the treatment. Topically applying ISCK03 effectively depigments UV-induced hyperpigmented spots. Fontana-Masson staining analysis reveals a reduction in epidermal melanin in areas treated with ISCK03[1].

ATP is dispensed into 384-well plates, chemical compounds (ISCK03: 2.5, 5, 10, 100 μM) are added by replicative plate, and recombinant human c-kit protein is added for the kinase reaction. Following a 45-min incubation at 37°C, the development reaction is carried out for 40 min at room temperature. After the reaction is stopped, the coumrain and fluorescein fluorescence-emission signals are detected[1].

To determine any cytotoxic effects of ISCK03 on 501mel cells, MTT assays are performed with various doses of ISCK03 (1, 5, 10 μM). 501mel cells are cultured with SCF alone (50 ng/mL) or SCF with ISCK03 for 48 h[1].