Neogenin expression is inversely associated with breast cancer grade in ex vivo

BACKGROUND: Neogenin is closely related to the human tumor suppressor gene deleted in colorectal cancer and plays a role in mammary morphogenesis. This study aimed to assess neogenin expression in breast cancer for any clinically significant association. METHODS: A total of 54 breast cancer patients who underwent modified radical mastectomy were enrolled for immunohistochemical and quantitative real-time PCR analysis of neogenin expression in their cancerous breast tissues in comparison to matching distant non-cancerous tissues. RESULTS: The data showed that the neogenin protein was either strongly or moderately expressed in the cytoplasm of the distant non-cancerous cells. In contrast, neogenin protein was either weakly or not expressed in the cytoplasm of 51/54 (94.4%) breast cancer cells, among which 13 breast cancer cases did not express neogenin protein at all (13/54, 24.1%). Similarly, levels of neogenin mRNA were significantly lower in breast cancer tissues than that of the matched distant non-cancerous tissues (51/54, 94.4%). Neogenin expression was inversely associated with breast cancer grade; that is, grade III breast cancer expressed much less neogenin than grade I-II (P < 0.05). CONCLUSIONS: This study indicates that neogenin expression in breast cancer tissues is inversely associated with tumor grade.