Differential Effects of Leptin on the Invasive Potential of Androgen-Dependent and -Independent Prostate Carcinoma Cells
Figure 4
Leptin stimulates early
phosphorylation of STAT-3 in PC-3 cells. PC-3cells (a) or LNCaP cells (c), devoid of growth factors by an overnight exposure to basal medium, were
exposed to increasing concentrations of leptin for various time points. of
the cell lysates obtained after each time point were separated on a 7.5%
SDS-PAGE and Western-blotted, and the phosphorylated STAT-3 proteins were
revealed by incubating with phospho-STAT-3 antibody followed by
chemiluminescent detection. The membranes were stripped and reprobed with
STAT-3 antibodies to verify the protein levels. In (b) and (d), densitometric analysis of phospho-STAT-3 and STAT levels was
determined. A time-course, dose-response curves of phosphor-STAT-3/STAT-3
(PSTAT/STAT) ratios for the effect of increasing leptin concentrations are
depicted for both (b) PC3 and (d) LNCaP. The original western blots are shown
in (a) and (c). Results shown are representative of three separate experiments.
