Next, to confirm our in vivo data mechanistically, in vitro analysis of the radiation response of cultured PC3 (+/−Cav1) and Cav1-deficient LNCaP prostate cancer cells were performed in the presence of supernatants (SN) derived from cultured Cav1-silenced HS5(−) or control transduced Cav1-expressing HS5(+) fibroblasts with or without radiation treatment (+/−XRT with 10 Gy) (Fig. 7). This evidence concerns the gene CAV1 and prostate carcinoma.