Activated 50Flanking Region ofNANOGP8 in a Self-Renewal Environment isAssociatedwith Increased Sphere Formation and Tumor Growth of Prostate CancerCells
Authors
Kai Zhang, Marcie Fowler, Jonathan Glass, and Hong Yin
Institution
Louisiana State
Country
United States
Year
2013
Journal
The Prostate
Abstract
INTRODUCTION. NANOGP8 is a retrogene which encodes a full-length protein similar to
the NANOG1 gene. The expression of NANOGP8 has been documented in several cancers
and is related to cell proliferation and tumor development. However, the regulation of
NANOGP8 expression has not been investigated. Therefore, the role of NANOGP8 in cell
proliferation has not been completely understood.
METHODS. We evaluate the expression of NANOG1 and NANOGP8 in prostate cancer cell
lines and primary cultures of prostate tissues. We investigate clonogenicity, sphere formation,
and xenograft tumor growth of prostate cancer cells with an activated 50flanking region of
NANOGP8.We examine the role of NANOGP8 in cell cycle progression.
RESULTS. In the prostate cells the NANOG RNA was transcribed from NANOGP8 and not
from NANOG1. Cells with the activated 50flanking region of NANOGP8 exhibited enhanced
clonogenicity, sphere formation, and xenograft tumor growth. The sphere culture and tumor
initiation mouse mode promoted the activation of the 50flanking region of NANOGP8. Forced
expression of NANOGP8 increased the entry into the cell cycle.
DISCUSSION. In prostate cells NANOGP8 is a predominant molecule of NANOG. The
activation of 50flanking sequence of NANOGP8 could play a role in the regulation of the stemlike
properties of cancer stem cells and prostate tumor initiation and development. The
microenvironment favoring cancer stem cells could promote the activation of the 50flanking
region of NANOGP8.