SOST and metastatic prostate carcinoma: Up-regulation of MALAT1 in metastatic prostate cancer (Figure 4A) and PC3 cells co-cultured with SostKO osteoblasts (Figure 3B) suggests that reduced Sost expression in the bone microenvironment may promote prostate cancer metastasis at least in part through the up-regulation of non-coding RNA MALAT1.