Abstract C68: Phenotypic and functional heterogeneity of prostate cancer stem cells

Abstract Recent evidence in many tumor systems suggests that there may exist several or even many tumorigenic subpopulations in each tumor. Utilizing 4 xenograft human prostate cancer (PCa) models, including two AR+/PSA+ (LAPC9 and LAPC4) and two AR-/PSA- (Du145 and PC3) xenografts, and by performing exhaustive limiting-dilution tumor regeneration assays in NOD/SCID mice using purified PCa cells based on functional properties (i.e., side population and Aldefluor assays) or preferential expression of surface markers (ABCG2, CD44, or integrin α2β1), we provide evidence for both the phenotypic and functional heterogeneity of PCa stem cells (i.e., PCa cell subpopulations with enhanced tumor-regeneration activity). Our results show that no single marker or assay seems to be able to capture all tumorigenic subsets in all 4 xenografts. We further show that different tumor-initiating subpopulations appear to co-exist in a common tumorigenic pool. We also demonstrate that some tumorigenic PCa cells overexpress stem cell-associated gene expression profiles. Finally, we provide evidence that primary prostate tumors possess subsets of tumor cells that bear similar phenotypic features to those in xenografts. Our results raise the possibility that different PCa patient tumors may harbor CSCs with distinct phenotypic and functional properties. Note: This abstract was not presented at the conference because the presenter was unable to attend. Citation Format: Xin Liu, Xin Chen, Brian Laffin, Binglan Yin, Tammy Calhoun-Davis, Feng Wang-Johanning, Dean G. Tang. Phenotypic and functional heterogeneity of prostate cancer stem cells [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr C68.