FIGURE 4.
PSMA expression of mouse RM1 versus human C4-2 prostate cancer cell lines. (A) PSMA expression was determined in vitro by flow cytometry for RM1-hPSMA (green), RM1-PGLS (blue), and C4-2 (red). RM1-PGLS cells exhibit heterogeneous PSMA expression, with PSMA-low (light blue) and PSMA-high (dark blue) subpopulations. (B) Mean absolute numbers of PSMA on cell surface were quantified on basis of mean fluorescence intensity values using antihuman IgG quantification beads. (C) Representative 68Ga-PSMA-11 PET/CT maximum-intensity projection of mice bearing equally sized subcutaneous mouse allografts or human xenografts. Mean %IA/g was 22.7, 17.4, and 15.5 for RM1-hPSMA, RM1-PGLS, and C4-2, respectively (n = 2 each).