Analysis of anchorage independent growth of human prostate cancer cell line LNCap

Abstract

LNCap, a human prostate cancer cell line, possess androgen dependent growth characteristics. We studied anchorage independent proliferation of LNCap cells using semi-solid agarose double layer culture. The cells formed colonies in the semi-solid medium supplemented with charcoal filtered steroid free fetal calf serum and maximal colony formation was obtained in the medium with 10% serum. The addition of several steroids (testosterone, dihydrotestosterone, ethinylestradiol) influenced the colony formation. Testosterone at the concentration of 10(-8) M to 10(-10) M stimulated colony formation with optiman of 10(-9) M. When LNCap cells were placed under the basal layer of the semi-solid culture as feeder cells, also stimulated was the colony formation of the LNCap cells cultured in upper layer of semi-solid medium. The addition of EGF, TGF alpha and TGF beta to the medium also stimulated the colony formation. The combined effect of EGF and TGF alpha was shown to be cooperative with testosterone. TGF beta, however, did not show such cooperative effect with testosterone on colony formation. The addition of the anti-body to EGF, TGF alpha or TGF beta to the medium decreased the colony formation of LNCap cells. These results suggest that LNCap cells excrete EGF, TGF alpha, TGF beta and/or similar substances and these factors autocrinely decorate the cell proliferation of LNCap human prostate cancer cells.