Preferential association of prostate cancer cells expressing prostate specific membrane antigen to bone marrow matrix.

Prostate specific membrane antigen (PSMA) is a transmembrane glycoprotein expressed almost exclusively in prostatic epithelial cells. Expression of PSMA is elevated in prostate cancer, with levels closely correlated with disease grade. Although the highest levels of PSMA expression are associated with high-grade, hormone-refractory and metastatic prostate cancer, the significance of elevated PSMA expression in advanced prostate cancer has yet to be fully elucidated. We provide evidence that prostatic carcinoma cells expressing PSMA exhibit reduced motility and increased attachment when grown on a bone marrow matrix substrate. This phenomenon occurs via activation of focal adhesion kinase and provides the first evidence of a link between PSMA expression and prostate cancer metastasis to the bone.