Regulation of the Chemokine Receptors CXCR4, CXCR7 , and the Androgen Receptor in Prostate Cancer

Abstract

The chemokine receptor CXCR4 contributes to tumour cell migration and invasion during the progression of prostate cancer. In particular, this pathway is central to the metastasis of prostate cancer to the bone marrow. Limited therapeutic options exist for prostate cancer patients who have progressed to advanced metastatic disease, and pharmacological interference of the chemokine network may serve to control tumour cell dissemination and the establishment of metastasis. A more detailed knowledge of the mechanisms regulating chemokine receptors is required, in order to further characterise and explore the capacity and effectiveness of targeting these pathways for therapeutic intervention in prostate cancer. Here, the regulation of CXCR4 protein expression and function was investigated in relation to androgens and the extracellular matrix. Accumulating evidence of CXCR4 regulation by androgens and the androgen receptor have indicated that androgens not only promote the growth and development of prostate cancer, but may actively contribute to the metastatic progression of prostate through modulation of the chemokine network. In the current study, the endogenous protein expression and functionality of the androgen receptor were firstly characterised in the androgen-insensitive prostate cancer cell lines DU145 and PC3, using the androgen-sensitive LNCaP cells as a basis for comparison. Investigations were performed using two-dimensional culture in conjunction with the more physiologically relevant three-dimensional in vitro culture model.