SC 66

SC66 inhibits cell viability and colony forming capacity of HCC cells with IC ₅₀ s of 0.77，0.47，0.92，0.75 and 2.85 μg/mL at 72 hours for HepG2, Hep3B, PLC/PRF/5，HA22T/VGH and Huh7 cells. HepG2, HA22T/VGH and PLC/PRF/5 cells have similar IC ₅₀ s of approximately 0.85 and 0.75 μg/mL at 48 and 72 hours, respectively. To determine whether the decrease in cell viability is related to apoptosis induction, TUNEL assays are performed in Hep3B and Huh7 cells treated with 1, 2 and 4 μg/mL of SC66 for 24 hours. In Hep3B cells the number of TUNEL-positive cells increased with increasing concentrations of SC66, whereas in Huh7 cells very few light brown-colored cells are observed only after treatment with 4 μg/mL SC66.

To demonstrate the effectiveness in vivo of SC66 on HCC, a mouse xenograft tumor model of Hep3B cells is used. When tumors became palpable, at a size of about 150 mm ³ , mice are randomized into three groups of 6 animals each. The treated group receive SC66 at 15 and 25 mg/kg twice a week via i.p. injection, while the untreated group receive the vehicle alone. Treatment with 25 mg/Kg SC66 significantly reduces tumor volume to 37% on day 17 when compared with tumors of the untreated group.