Identification of URIM, a novel gene up-regulated in metastasis

URIM (Up-Regulated In Metastasis) was identified as a new gene by Different ial Display Technique during investigation of the transcriptional pattern o f a metastasizing (NMCL-1) and a non-metastasizing (530) human melanoma cel l line. The protein is encoded by 206 amino acids with an isoelectric point of 10.4. In addition URIM displays a putative nuclear localization signal and a putative leucine zipper suggesting that URIM may function as a nuclea r protein. Expression of URIM in several normal tissues and tumor cell line s was studied by Not-them blotting Surprisingly, 17 fold increased steady-s tate mRNA levels for URIM were detected in three cell lines derived from bo ne marrow micrometastasis of mammary carcinoma and one mammary carcinoma ce ll line derived from ascites fluid compared to normal epithelial cells from mammary gland and two cell lines derived from primary mammary carcinoma. T hese findings indicate that expression of URIM might be deregulated in meta stases of different types of tumors.