Nanog: a potential biomarker for liver metastasis of colorectal 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.