Prognostic significance of NANOG and KLF4 for breast cancer

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. In 100 breast cancer patients, the expression of c-MYC, KLF4, NANOG, OCT4, and SOX2 was determined by immunohistochemistry using a tissue microarray analysis. 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). 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.