Sterile Alpha Motif Domain Containing Protein 9 (SaMD9)

SAMD9 encodes a 1,589-amino acid protein that is expressed in a wide range of tissues, including skin. Quantitative real-time PCR showed that the gene is strongly expressed in endothelial cells and, to a lesser degree, in fibroblasts.SAMD9 was one of the most differentially regulated genes in an aggressive fibromatosis tumor with inactivation of the APC gene compared with the same cells after transfection of wildtype APC. Knockdown of SAMD9 by RNA interference increased the proliferation and invasiveness of a normal lung fibroblast cell line, whereas SAMD9 overexpression reduced cell proliferation and motility, and increased apoptosis in a colon cancer cell line. SAMD9 overexpression reduced tumor volume following transplantation in immune-deficient mice.