Isolation and characterization of LNCaP sublines differing in hormone sensitivity.

Prostate cancer is a heterogeneous disease with varying degrees of androgen sensitivity. In this study, we performed a limiting dilution of human prostate LNCaP cells, and isolated two sublines, LNCaP-E9 and LNCaP-G4, with differential hormone-sensitivity. Two LNCaP sublines were obtained by the limiting dilution method. The growth of E9 cells was decreased in the presence of androgens, while that of androgen-treated G4 cells was biphasic. Although the androgen receptor expression level in E9 cells was similar to that seen in G4 cells, the expression of PSA mRNA and protein was significantly lower in the E9 cells. Moreover, the androgen-based stimulation of PSA mRNA expression was less sensitive in E9 cells than G4 cells. Intracellular zinc level did not differ between E9 and G4 cells, but ZnT3 mRNA expression was significantly higher in the E9 cells. When the cells were grafted at the subrenal capsule, the number of CD31-positive vessels with a lumen was approximately 2.5 times higher than that in G4 tumors. LNCaP-E9 cells show lower androgen sensitivity than LNCaP-G4 cells. E9 and G4 cells would be helpful for understanding the biology of hormone-refractory prostate cancer.