Enhanced androgen sensitivity in serum-free medium of a subline of the LNCaP human prostate cancer cell line.

The LNCaP-Fast Growing Colony (FGC) human prostate cancer cell line proliferates in response to the addition of dihydrotestosterone (DHT) 10(-10)-10(-8) M in charcoal-stripped serum-supplemented media. LNCaP-FGC cells will not attach or proliferate in serum-free conditions. LNCaP-FGC stock cultures were maintained in medium supplemented with 10% FBS and added DHT (10(-9) M) for > 25 passages (6 months). The resultant subline was designated as LNCaP-ss (supersensitive) because of its ability to attach in serum-free medium and to proliferate in response to very low levels of DHT. LNCaP-ss cells were grown in serum-free medium and proliferation assessed after 2, 3, 5, and 7 days' treatment with DHT. Significant enhancement of growth was demonstrated after 7 days' treatment with DHT over a wide range of concentrations (DHT 10(-15)-10(-7) M) with maximal stimulation (3 x control, p < .001) noted with DHT 10(-14) M. Changing the medium during the course of the experiment decreased, but did not eliminate, the DHT-induced cellular proliferation. Scatchard analysis of binding studies with LNCaP-ss cells revealed that both the Kd for the androgen receptor (AR) and the number of AR sites/cell were similar to the corresponding values reported for the parental line. AR mRNA levels in LNCaP-ss cells, as measured by RNase protection assay, were significantly down-regulated by 7 days' treatment with DHT 10(-15), 10(-13), and 10(-9) M.(ABSTRACT TRUNCATED AT 250 WORDS)