Figure 1.

Leptin increases cell proliferation in androgen-resistant prostate cancer cell lines ((a); PC-3, (b); DU145) in a dose-dependent manner. Conversely, leptin's proliferative effect on androgen-sensitive cell line ((c); LNCaP) was much less pronounced. Cells were cultured in serum-free media for 24 hours (white bars) or 48 hours (black bars) in the presence or absence of leptin (0–100 ng/mL) and cell numbers were determined by a colorimetric XTT assay. Assays were performed at least five times and samples were run in triplicate. The data (means ± SEM) are reported as a percentage of results in untreated controls and asterisks or pound signs denote values significantly different from these cells at 24 and 48 hrs, respectively, (* or ^# P < 0.05; ** or ^## P < 0.01; *** or ^### P < 0.001 by ANOVA).