Estrogen Receptors Promote Migration, Invasion and Colony Formation of the Androgen-Independent Prostate Cancer Cells PC-3 Through β-Catenin Pathway

Abstract

Prostate cancer is initially dependent on the androgen, gradually evolves into an androgen-independent form of the disease, also known as castration-resistant prostate cancer (CRPC). At this stage, current therapies scantily improve survival of the patient. Androgens and estrogens are involved in normal prostate and prostate cancer development. The mechanisms by which estrogens/estrogen receptors (ERs) induce prostate cancer and promote prostate cancer progression have not yet been fully identified. Our laboratory has shown that androgen-independent prostate cancer cells PC-3 express both ERα and ERβ. The activation of ERβ increases the expression of β-catenin and proliferation of PC-3 cells. We now report that the activation of ERβ promotes the increase of migration, invasion and anchorage-independent growth of PC-3 cells. Furthermore, the activation of ERα also plays a role in invasion and anchorageindependent growth of PC-3 cells. These effects are blocked by pretreatment with PKF 118-310, compound that disrupts the complex β-catenin/TCF/LEF, suggesting that ERs/β-catenin are involved in all cellular characteristics of tumor development in vitro. Furthermore, PKF 118-310 also inhibited the upregulation of vascular endothelial growth factor A (VEGFA) induced by activation of ERs. VEGF also is involved on invasion of PC-3 cells. In conclusion, this study provides novel insights into the signatures and molecular mechanisms of ERβ in androgen-independent prostate cancer cells PC-3. ERα also plays a role on invasion and colony formation of PC-3 cells.

Estrogen Receptor Signaling Pathways Involved in Invasion and Colony Formation of Androgen-Independent Prostate Cancer Cells PC-3

“…PC-3 or DU-145 cells (2 × 10 5 cells) in serum free culture medium were seeded in ThincertR chambers (Greiner Bio-one, Kremsmünster, Austria) with polyethylene terephthalate membranes (8 mm pore size) pre-coated with 50 mL of phenol red-free Matrigel (1:10, BD, Corning). These chambers were placed in 24-well plates containing culture medium with 10% FBS in the lower chamber [ 10 , 34 ]. PC-3 or DU-145 cells in upper chambers were incubated in the absence (control) and presence of 17β-estradiol (E2, 10 nM) or DPN (10 nM) or PPT (10 nM) for 48 h at 37 °C.…”

“…Incubation was continued in the absence and presence of E2 (10 nM) or DPN (10 nM) or PPT (10 nM) for 48 h at 37 °C. Cell invasion analyses were performed as previously described [ 10 ]. The chambers were washed thoroughly with 10 mM PBS, fixed in 4% paraformaldehyde for 30 min, and stained with 0.2% crystal violet for 10 min.…”

“…PC-3 cells (6 × 10 3 cells) in culture medium containing 10% FBS and 0.35% agarose (low melting, Sigma Chemical Co.) were seeded in 24-well plates pre-coated with 300 mL of 0.7% agarose at 4 °C for 30 min [ 10 , 34 ]. Cells were incubated at 37 °C for 2 h. Afterward, this culture medium was replaced by culture medium containing 10% SFB, pretreated with activated charcoal (0.25%) and dextran T-70 (0.0025%), for 24 h at 37 °C.…”

“…Cells were also untreated or pretreated with PP2 (5 nM), Wortmannin (1 µM) or MK2206 (200 nM), for 30 min. Incubation was continued in the absence and presence of E2 (10 nM) DPN (10 nM) or PPT (10 nM) for 3 weeks at 37 °C [ 10 ]. Colony formation analyses were performed as previously described [ 10 ].…”

“…The activation of ERβ promotes the increase of migration, invasion, and anchorage-independent growth of PC-3 cells through β-catenin pathway. The activation of ERα also plays a role on invasion and anchorage-independent growth of PC-3 cells [ 10 ]. However, the molecular mechanisms of the crosstalk between ER and β-catenin pathways in this cell remains to be elucidated.…”