79923

NANOG

Nanog homeobox;NANOG;Nanog homeobox

homeobox protein NANOG|homeobox transcription factor Nanog|homeobox transcription factor Nanog-delta 48

12p13.31

protein-coding

BACKGROUND: Some of the induced pluripotent stem cell (iPS cell)-inducing factors have been reported to be expressed in breast cancer. The aim of the present study was to examine the relationship between the expression of iPS cell-inducing factors and the prognosis of breast cancer patients. METHODS: In 100 breast cancer patients, the expression of c-MYC, KLF4, NANOG, OCT4, and SOX2 was determined by immunohistochemistry using a tissue microarray analysis. RESULTS: Patients with strong expression of NANOG had significantly lower disease-free survival (DFS) and overall survival rates than those with weak expression of NANOG (P = 0.004 and 0.033, respectively). In contrast, patients with strong expression of KLF4 had better DFS (P = 0.014). CONCLUSIONS: Strong expression of NANOG is an indicator of a poor prognosis for breast cancer patients, whereas KLF4 is a favorable prognostic indicator. Our results suggest that NANOG stimulates the growth and metastasis of breast cancer cells, whereas KLF4 inhibits these processes.

Nanog is a transcription factor required for maintaining the pluripotency of embryonic stem cells, and is not expressed in most normal adult tissues. However, recent studies have indicated that Nanog is overexpressed in many types of human cancers, including breast cancer. To elucidate the physiological roles of Nanog in tumorigenesis, we developed an inducible Nanog transgenic mouse model, in which the expression of Nanog in adult tissues can be induced via LoxP/Cre-mediated deletion. Our findings indicate that overexpression of Nanog in the mammary gland is not sufficient to induce mammary tumor. However, when coexpressed with Wnt-1 in the mouse mammary gland, it promotes mammary tumorigenesis and metastasis. In this context, Nanog promotes the migration and invasion of breast cancer cells. Microarray analysis has shown that the ectopic expression of Nanog deregulates the expression of numerous genes associated with tumorigenesis and metastasis, such as the PDGFRalpha gene. Our findings demonstrate the involvement of Nanog in breast cancer metastasis, and provide the basis for the reported correlation between Nanog expression and poor prognosis of human breast cancer patients. As Nanog is not expressed in most adult tissues, these findings identify Nanog as a potential therapeutic target in the treatment of Nanog-expressing metastatic breast cancer.

BACKGROUND: At present, the relationship between Nanog expression and the biological behavior and prognosis of colorectal cancer is still unclear. AIM: The purpose of this study was to evaluate the expression and regulatory effects of Nanog in colorectal cancer and the correlation between Nanog protein expression and the prognosis of patients with colorectal cancer. MATERIALS AND METHODS: The differential expression of genes between CD133+ tumor cells and CD133- tumor cells were detected using RT(2) Profiler PCR Array. The Nanog mRNA expression level was detected by RT-PCR and the protein level was detected using immunohistochemistry staining. The relationship between Nanog expression and clinicopathological parameters of colorectal cancer was determined. RESULTS: Nanog were expressed significantly higher in CD133+ tumor cells compared to CD133- tumor cells. It was observed that 72 (20.00 %) of the 360 cases positively expressed Nanog. Univariate analyses indicated that Nanog expression was related to histological grade, lymph node metastasis, TNM stage, and liver metastasis (P = 0.005, 0.001, 0.001 and 0.012, respectively). Spearman correlation analysis showed that Nanog expression has a linear correlation to liver metastasis (P = 0.001). After conducting multivariate analysis, histological grade, TNM stage, and Nanog were found to be related to liver metastasis (P = 0.020, 0.01 and 0.001, respectively). In the Cox regression test, the histological grade, Lymph node metastasis, TNM stage, liver metastasis, and Nanog were detected as the independent prognostic factors (P = 0.02, 0.045, 0.01, 0.001 and 0.001, respectively). CONCLUSIONS: Nanog protein may be a potential biomarker for postoperative liver metastasis of colorectal cancer.