Ki-67 proliferative index in both epithelial and stromal compartments of human prostate xenografts at 7, 30, 90, and 200 days post-implantation.

<p>While an increasing percent of epithelial cells is proliferating over time, estrogen treatment does not affect prostate xenograft growth in the 7, 30 or 90-day xenografts in either the (<b>A</b>) epithelial or (<b>B</b>) stromal compartments. At 200 days post-implantation (<b>C</b>) there is a significant increase in epithelial proliferation in xenografts given an initial and secondary treatment of estrogen compared to control, (<b>D</b>) while there was no significant change in the stromal compartment. (<b>C-D</b>) The x-axis on the 200-day bar graphs are depicted as initial/secondary treatment in which C = control, and E = estrogen treatment. Ki-67 positive nuclei were measured as a percent of the total number of nuclei in each respective compartment. Line and bar graphs indicate the mean % Ki-67 positive cells ± SEM, ** indicates t-test significance relative to control of p<0.01. Legend: —●— Control, -■- Estrogen. Age of human fetal prostate prior to implantation was 15–21.5 weeks gestation. Sample size (n) for each group is as follows: 7D control (3), 7D estrogen (2), 30D control (3), 30D estrogen (4), 90D control (4), 90D estrogen (5), 200D control/control (4), 200D estrogen/control (4), 200D control/estrogen (2), 200D and estrogen/estrogen (4).