Review
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World J Gastroenterol. Sep 28, 2014; 20(36): 13071-13078
Published online Sep 28, 2014. doi: 10.3748/wjg.v20.i36.13071
NANOG: A promising target for digestive malignant tumors
Ai-Xi Sun, Chang-Jiang Liu, Zi-Qin Sun, Zhi Wei
Ai-Xi Sun, Chang-Jiang Liu, Zi-Qin Sun, Zhi Wei, Department of Gastroenterology, The General Hospital of Jinan Military Command, Jinan 250031, Shandong Province, China
Author contributions: Sun AX and Liu CJ equally contributed to this paper; Liu CJ designed the article; Sun ZQ designed and revised the paper; Sun AX wrote the paper; Wei Z revised the paper.
Supported by Natural Science Foundation of Shandong Province, No. ZR2011HM021
Correspondence to: Zi-Qin Sun, MD, PhD, Department of Gastroenterology, The General Hospital of Jinan Military Command, No. 25 Shifan Road, Tianqiao District, Jinan 250031, Shandong Province, China. ziqins@126.com
Telephone: +86-531-51665320 Fax: +86-531-51665254
Received: February 14, 2014
Revised: May 3, 2014
Accepted: June 13, 2014
Published online: September 28, 2014
Processing time: 229 Days and 9.8 Hours
Abstract

NANOG has been extensively researched since its discovery by Chambers et al. NANOG is a homeodomain transcription factor and an essential regulator of embryonic stem cell (ESC) self-renewal, which inhibits differentiation. Cancer stem cells (CSCs) are a small subset of cells that are thought to drive uncontrolled tumor growth; CSCs retain the tumor capabilities of self-renewal and propagation. The existence of CSCs was recently shown by direct experimental evidence. NANOG is expressed in CSCs and ESCs, although it remains unclear whether ESCs and CSCs share similar mechanisms in the regulation of physical and biological processes. Several studies suggest that the expression level of NANOG is high in cancer tissues and low or absent in normal tissues. High levels of NANOG expression are associated with advanced stages of cancer and a poor prognosis, indicating that it plays a vital role in tumor transformation, tumorigenesis, and tumor metastasis. NANOG is part of a complex regulatory network that controls cell fate determination, proliferation, and apoptosis. NANOG cooperates with other regulators, such as microflora, transcription factors, and kinases, in cancer cells. NANOG might have a promising future in anti-cancer and other therapeutic treatments, which could improve human health.

Keywords: NANOG; Cancer stem cells; Gastrointestinal tumor; Anti-cancer

Core tip: This review article differs from previous reviews by concentrating on the relationship between NANOG and cancer. This review contains the following five sections: the structure of NANOG, NANOG and cancer stem cells, signal pathways associated with NANOG in cancer, NANOG in specific human tumors, and the role of NANOG in anti-cancer therapy. Each section contains novel insights and comprehensively reviews the current literature, which will be very useful to the journal’s readers.