SBF-1 strongly inhibited the growth of both
ARWT and ARmutant prostate cancer in
nude mice
Finally, the effect of SBF-1 on prostate cancer growth in vivowas tested. Nude mice were injected s.c. with LNCaP or
PC3/AR+ cells. After the tumor reached 50
mm3, SBF-1 was administered i.p. at 10 and 30 µg/kg.
SBF-1 significantly reduced the tumor size in mice, in a dose-dependent
manner (Fig. 6A and B). At the end of treatment, animals were injected
with ICG dye-conjugated IGF-1 antibody and after 3 hours from injection,
the tumor size and the fluorescent intensity were measured. SBF-1
dramatically reduced both tumor size and the fluorescent intensity of
IGF-1 in mice at such very low doses in a dose-dependent manner,
suggesting a relation of the strong inhibition of tumor growth to the
reduced IGF-1 expression (Fig. 6C-F). In this case, SBF-1 significantly
avoided the decrease in body weights of mice bearing tumor (Fig. 6G and
H) and prolonged the survival rate (Fig. 6I and J). In addition, SBF-1
inhibited the expressions of pARS515,
pAKTS473, pFOXO1S256, IGF-1, PCNA, and
Bcl-2 proteins extracted from the tumor tissues in both models (Fig. 6K
and L).