CXCR7 antagonist, CCX771, inhibits CRPC cell proliferation and migration. A, Cell viability of C4–2B, PC-3, and DU145 cells was measured by Alamar Blue 5 days after treatment with different concentration of CCX771. All cells were grown in the RPMI 1640 with 5% FBS. B, Same experiments were performed after treatment with AMD3100. C, C4–2B cells were grown in the RPMI 1640 with 5% CSS. Cell viability was measured by Alamar Blue 5 days after treatment with CCX771 in the presence or absence of DHT (10 nM) D, C4–2B cells were grown in the RPMI 1640 media with 5% FBS. Cell viability was measured in the presence or absence of 10 μM enzalutamide (ENZ). E, Representative images of transwell migration assays in C4–2B cells after treatment with CCX771 (5 μM) or AMD3100 (10 μM). The images were quantified using ImageJ software. F, Same experiments were performed in PC-3 cells. Data are representative of three independent experiments. Mean ± SD is plotted. P-value was determined by two-tailed Student’s t-test. *** p < 0.0001.