Integrin expression and usage by prostate cancer cell lines on laminin substrata.

During prostate cancer progression, invasive glandular epithelial cells move out of the ductal-acinar architecture and through the surrounding basement membrane. Extracellular matrix proteins and associated soluble factors in the basal lamina and underlying stroma are known to be important regulators of prostate cell behaviors in both normal and malignant tissues. In this study, we assessed cell interactions with extracellular matrix and stromal factors during disease progression by characterizing integrin usage and expression in a series of parental and lineage-derived LNCaP human prostate cancer cell lines. Although few shifts in integrin expression were found to accompany disease progression, integrin heterodimer usage did change significantly. The more metastatic sublines were distinct in their use of alphavbeta3 and, when compared with parental LNCaP cells, showed a shift in alpha6 heterodimerization, a subunit critical not only for interaction with prostate basal lamina but also for interaction with the bone matrix, a favored site of prostate cancer metastases.