Fig 1.

Isolation of subpopulations of prostate cancer cells by differential adherence. A: Multiple prostate cancer cell lines were allowed to adhere to either laminin-, collagen I-, collagen IV-coated plates, or plates coated with all three combinations. Time of adherence assay is described where PCa cells are allowed to adhere for 5 minutes, the rapidly adherent cells after 5 min (5′) are collected, the remaining of the cells are replated for 20 min, the cells that adhere at 20 min (20′) are collected, and the cells that did not adhere (>20′) are labeled as non-adherent cells. Data are shown for DU145 cells from six separate adhesion experiments. B: Fractions of PC3 and DU145 cells collected after time-of-adherence assay were subjected to flow cytometric analysis of α2β1-integrin expression. Representative flow cytometric analysis is shown for PC3 and DU145 cells. C: Percentages of collagen-I adherent and non-adherent PC3 and DU145 cells immediately after collagen adherence assay. D: Cell viability of collagen-I adherent and non-adherent PC3 and DU145 cells immediately after the collagen adherence assay were similar to cell viabilities of adherent and non-adherent cells immediately after cell isolation, and averaged 95–99.9%.