GPNMB [SEP] found in taxon
metastatic human melanoma cell lines and xenografts and not expressed in highly metastatic cell lines. However, several recent studies have identified high GPNMB expression in aggressive melanoma, glioma, and breast cancer specimens.
Clinical and functional significance in cancer Breast cancer.
Based on Immunohistochemical analysis, two studies have shown that GPNMB is commonly expressed in breast tumors. In the first study, GPNMB was detected in 71% (10/14) of breast tumors. In the second study, 64% of human breast tumors express GPNMB in the tumor stroma
and an additional 10% of tumors express GPNMB in the tumor epithelium. In this study it was reported that GPNMB expression in the tumor epithelium was an independent prognostic indicator of breast cancer recurrence. Moreover, epithelial GPNMB expression was most abundant in triple negative breast cancers and it was found to be a prognostic marker for shorter metastasis-free survival times within this breast cancer subtype. Finally, GPNMB expression in breast cancer cells is capable of promoting cell migration, invasion, and metastasis both "in vitro" and "in vivo