Estrogen Receptor Signaling Pathways Involved in Invasion and Colony Formation of Androgen-Independent Prostate...

Area of Science:

• Molecular Oncology
• Cell Signaling
• Cancer Biology

Background:

• Castration-resistant prostate cancer (CRPC) is an advanced, androgen-independent form of prostate cancer.
• Estrogen receptor (ER) signaling is increasingly recognized for its role in CRPC progression.
• Previous work indicated ER promotes migration and invasion in androgen-independent prostate cancer cells (PC-3), but underlying pathways were unclear.

Purpose of the Study:

• To investigate the roles of ERα and ERβ in activating SRC signaling.
• To determine the involvement of SRC and PI3K/AKT pathways in PC-3 cell invasion and colony formation.
• To elucidate the extranuclear molecular mechanisms by which ER enhances prostate cancer cell tumorigenicity.

Main Methods:

• Utilized selective ERα (PPT) and ERβ (DPN) agonists to activate estrogen receptors in PC-3 cells.
• Employed a selective SRC-family kinase inhibitor (PP2) to assess SRC's role in cell migration and colony formation.
• Used specific inhibitors for PI3K (Wortmannin) and AKT (MK2206) to evaluate their involvement in ER-stimulated invasion and colony formation.

Main Results:

• Activation of ERα and ERβ significantly increased SRC phosphorylation in PC-3 cells.
• Inhibition of SRC kinase activity reduced ER-mediated transmigration and soft agar colony formation.
• SRC activation was linked to the expression of non-phosphorylated β-catenin.
• PI3K/AKT signaling pathways were found to be essential for ER-stimulated PC-3 cell invasion and colony formation.

Conclusions:

• Estrogen receptors (ER), acting extranuclearly, rapidly activate SRC and PI3K/AKT signaling molecules.
• This ER-mediated signaling cascade enhances prostate cancer cell proliferation, migration, invasion, and tumor formation.
• The findings reveal novel molecular mechanisms underlying ER's contribution to CRPC progression.