Expression profiling of stroma cells from prostate cancer co-cultures, with or without TGF-beta signaling

Prostate stroma-specific TGF-beta signaling induces morphological changes in LNCaP cells. We have previously shown that stromal TGF-beta signaling regulates prostate tumor growth. To further delineate the underlying mechanisms, we generated LNCaP cells overexpressing an HA-tagged constitutively activate TGF-beta1 ligand (LNCaP-HA-TGF-β1(a)) and control LNCaP cells (LNCaP-Ctrl), and performed in vitro co-cultures of LNCaP-HA-TGF-β1(a) and LNCaP-Ctrl cells on top of the confluent HPS-19I cells, a human prostate stromal cell line. Since LNCaP cells are defective in TGF-beta receptor I (TbetaRI / ALK-5) that is essential for mediating TGF-beta signaling, only HPS19I cells are able to respond to TGF-beta ligand in these co-cultures. This provides a unique opportunity to study how prostate stromal cell-specific TGF-beta signaling regulates PCa biology. To identify the prostate epithelia-specific gene that was regulated by prostate stromal TGF-beta signaling, we also treated HPS19I cells using conditioned media collected from LNCaP- HA-TGF-β1(a) cells and LNCaP-Ctrl cells cultured in RPMI1640 supplemented with 0.2% FBS. After 6 days of treatment, we extracted total RNA from these HPS19I cells and performed microarray. HPS-19I prostate stroma cells from LNCaP+HPS-19I co-culture, with or without TGF-beta KEYWORDS: two group comparison