c-Met inhibitors suppressed growth of AR positive prostate cancer cells, especially androgen insensitive type. (A) Both LNCaP and LNCaP C4-2 cells were analyzed in MTS assay in the presence of PHA-665752. The average relative cell proliferation after 8 days as a percentage of proliferation in the DMSO vehicle control ± SE of triplicate samples was plotted, and the significant difference was observed as *P < 0.01 (Student's t test). (B) The effect of PF-2341066 on LNCaP and LNCaP C4-2B cells was tested and analyzed similarly as (A). The significant difference was shown, *P < 0.01 (Student's t test). (C) Approximately 50 LNCaP or LNCaP C4-2 cells per well were plated in quadruplicate in 6-well plates for 24 hr, and then 5 μM of PHA-665752 or PF-2341066 was added. Cells were fixed and stained with crystal violet in methanol at day 10. (D) The relative anti-proliferative effect of PHA-665752 or PF-2341066 at 2.5 μM on different prostate cancer cells was compared. A significant difference, **P < 0.01 (Student's t test), between two AR positive cell lines, LNCaP and LAPC4, and other AR negative and androgen insensitive cells was observed.