Androgen‐dependent growth regulation of and release of specific protein(s) by the androgen receptor containing human prostate tumor cell line LNCaP

Abstract

Hormone sensitivity, as indicated by the presence of steroid hormone receptors and by the effect of androgens and anti-androgens on the release of proteins by cultured cells of the human prostate tumor cell line lymph node carcinoma of the prostate-fast growing colony (LNCaP-FGC), has been studied. The growth of the LNCaP-FGC cells were stimulated by androgens in a dose-dependent way. Under optimal conditions the synthetic nonmetabolizable androgen 17 beta-hydroxy-17 alpha-methyl-(3H)-estra-4,9,11-trien-3-one (R1881) (0.1 nM) stimulated cell growth by approximately 2.3 times. Increasing doses of R1881 (1-100 nM) partly decreased the stimulation of the cell growth. The anti-androgen cyproterone acetate exerted inhibitory effects on cell growth. The nuclear extract of the LNCaP-FGC cells contained 17,000 +/- 2,500 (mean +/- SD) KCl-extractable, nuclear androgen receptor sites/cell. Estrogen and progesterone receptors were not detectable in the nuclear extracts nor in cytosol, indicating that these receptors were absent. The release of proteins in the culture medium was studied using incorporation of the 35S-methionine, sodium dodecyl sulfate (SDS)-gel electrophoresis, and fluorography. Cells grown in media containing charcoal-stripped fetal calf serum released significantly lower amounts of a protein with an apparent molecular mass of 42,000 daltons. The release of this 42-kD protein could be restored in cells cultured in the presence of 5 alpha-dihydrotestosterone (0.1-1 microM) or R1881 (0.1-100 nM), whereas the addition of estrogens or corticosteroids had no effect. In the presence of anti-androgens, such as cyproterone acetate and 5,5-dimethyl-3-(4-nitro-3-(trifluoro-methyl)-phenyl)-2,4-imidasolidin edione, inhibitory effects on the release of the 42-kD protein were observed. The observed parallel between the effects of (anti)-androgens on the growth of the LNCaP prostate cells and the release of the 42-kD protein suggests that this protein is involved in the regulation of malignant prostate cell growth.

Synthetic androgens suppress the transformed phenotype in the human prostate carcinoma cell line LNCaP

“…The weak effect of DHT is probably due to its rapid metabolism to polar compounds (Berns et al, 1986 Values represent the cell number in hormone containing samples as per cent of the cell number of untreated controls which are defined as 100%. The standard deviation is given in brackets.…”

“…Many cell culture studies used charcoal-stripped foetal calf serum (FCS;van Steenbrugge et al, 1989;Berns et al, 1986;Schuurmans et al, 1988a-c;Schuurmans et al, 1989;Wilding et al, 1989) to control the concentration of steroids in the medium rigorously. The results obtained with charcoal-stripped foetal calf serum (FCS) demonstrate biphasic androgen induction of epidermal growth factor-receptor and growth stimulation of LNCaP cells.…”

“…The results obtained with charcoal-stripped foetal calf serum (FCS) demonstrate biphasic androgen induction of epidermal growth factor-receptor and growth stimulation of LNCaP cells. At concentrations below 10-1lM, the synthetic androgen methyltrienolone (R1881) stimulates proliferation in a dose-dependent manner, above this threshold growth stimulation decreases (Berns et al, 1986 Although charcoal-stripping of FCS provides the opportunity to create a more defined and reproducible hormonal environment, indiscriminate removal of hydrophobic substances may be detrimental to cell viability and only poorly reflect the in vivo situation (Horoszewicz et al, 1983). The proliferation of LNCaP cells is severely inhibited in medium containing charcoal-stripped serum (Sonnenschein et al, 1989), and according to the majority of published studies, androgens cannot fully compensate the effect of charcoal treatment (van Steenbrugge et al, 1989).…”

Expression of Structurally Unaltered Androgen Receptor in Extramammary Paget's Disease

“…The quality of cDNA synthesis was monitored by PCR amplification using ␤-actin primers. cDNA from a prostate carcinoma cell line, LNCaP (Berns et al, 1986), was also used as a positive control. Five cDNA samples from normal lymph nodes obtained from melanoma patients who underwent elective lymphadenectomy (Hatta et al, 1998) were also used as negative controls.…”

Effects of new 17α-hydroxylase/C17,20-lyase inhibitors on LNCaP prostate cancer cell growth in vitro and in vivo

“…LNCaP cells remain the only androgen receptor (AR)-positive prostate cancer cell line, that can be readily grown in tissue culture (Horoszewicz et al, 1983). These cells respond to androgens with increased cell proliferation and elevated expression of prostate specific antigen (PSA) (Berns et al, 1993). LNCaP cells at early passages are not only androgen-responsive, but also androgendependent (Pousette et al, 1997).…”