Abstract C64: Adult murine prostate basal and luminal cells are self-sustained lineages that can both serve as targets for prostate cancer initiation

Abstract

Abstract The prostate epithelial lineage hierarchy and the cellular origin for prostate cancer remain inadequately defined. We sought to utilize a lineage tracing approach to define the epithelial lineage hierarchy in the prostate. A previously reported K14-CreER transgenic mouse line was bred with a fluorescent reporter line to specifically label the prostate basal cell lineage. In parallel, the prostate luminal cell lineage was labeled with fluorescence using a novel K8-CreERT2 transgenic mouse line generated in our own lab. Using this lineage tracing approach, we show that adult rodent prostate basal and luminal cells are independently self-sustained in vivo. We then sought to characterize the cells of origin for prostate cancer in the context of loss of function of Pten, which occurs frequently in primary and advanced human prostate cancer. We bred the K14-CreER and K8-CreERT2 mouse lines with Ptenfl/fl mice separately so that Pten expression can be disrupted specifically in prostate basal and luminal cells, respectively. Disrupting Pten in either lineage led to prostate cancer initiation. However, the cellular composition and onset dynamics of the resulting tumors are distinctive. Prostate luminal cells are more responsive to Pten null-induced mitogenic signaling. In contrast, basal cells are resistant to direct transformation. Instead, loss of Pten activity induces the capability of basal cells to differentiate into transformation-competent luminal cells. These studies suggest that deregulation of the normal prostate epithelial differentiation program is a critical step for initiation of human prostate cancer with a basal cell origin. Furthermore, suppressing signaling pathways that induce basal-luminal differentiation may provide an efficient approach to prevent prostate cancer initiation. Citation Format: Nahyun Choi, Boyu Zhang, Li Zhang, Michael Ittmann, Li Xin. Adult murine prostate basal and luminal cells are self-sustained lineages that can both serve as targets for prostate cancer initiation [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 C64.