Sox2 expression promotes castration resistant prostate cancer tumor formation.

<p><b>A</b>) Ectopic expression of Sox2 in castrate-sensitive LAPC-4 (LV-Sox2, n = 10 mice) cells is sufficient to promote tumor take in castrated male nude hosts compared to control mice (LV-Control, n = 10) (p = 0.019). Inset: western blot documenting ectopic lentiviral Sox2 expression in LAPC-4 cells. GAPDH was used as a loading control. NCCIT cells are used as a Sox2-positive control. <b>B</b>) Castrated LAPC-4-Sox2 versus LAPC-4-Control tumors do not have differences in serum PSA density. These data support that Sox2 expression does not confer a less-differentiated tumor phenotype. PSA density is the ng/mL total PSA per gram tumor. <b>C</b>) Expression of Sox2 in LAPC-4 does not significantly increase the percentage of rare CD133-positive cells, which are thought to be putative cancer stem/initiating cells.