Loss of NDRG2 Expression Confers Oral Squamous Cell Carcinoma with Enhanced Metastatic Potential
CANCER RESEARCH
Authors: Tamura, Tomohiro; Ichikawa, Tomonaga; Nakahata, Shingo; Kondo, Yudai; Tagawa, Yuri; Yamamoto, Koji; Nagai, Kentaro; Baba, Takashi; Yamaguchi, Ryoji; Futakuchi, Mitsuru; Yamashita, Yoshihiro; Morishita, Kazuhiro
Abstract
Loss of the tumor suppressor NDRG2 has been implicated in the development of oral squamous cell carcinoma (OSCC), acting by modulating PI3K/AKT-mediated dephosphorylation of PTEN at S380/S382/T383 (STT). Here, we show that the majority of OSCC tumors with lymph node metastasis, a major prognostic factor, exhibit high levels of phosphorylated AKT-S473 and PTEN-STT and low levels of NDRG2 expression. In Ndrg2-deficient mice, which develop a wide range of tumors, we developed a model of OSCC by treatment with the tobacco surrogate 4-nitroquinoline-1-oxide (4-NQO). In this model, both the number and size of OSCC tumors were increased significantly by Ndrg2 deficiency, which also increased invasion of cervical lymph nodes. 4-NQO treatment of human OSCC cell lines exhibiting low NDRG2 expression induced epithelial-mesenchymal transition via activation of NF-kB signaling. Conversely, ectopic expression of NDRG2 reversed the EMT phenotype and inhibited NF-kB signaling via suppression of PTEN-STT and AKT-S473 phosphorylation. Our results show how NDRG2 expression serves as a critical determinant of the invasive and metastatic capacity of OSCC. (C) 2017 AACR.
NDRG2 is expressed on enteric glia and altered in conditions of inflammation and oxygen glucose deprivation/reoxygenation
JOURNAL OF MOLECULAR HISTOLOGY
Authors: Zhang, Yuxin; Gao, Hui; Li, Na; Chang, Haiqing; Cheng, Bo; Li, Yansong; Miao, Jiwen; Li, Shuang; Wang, Qiang
Abstract
Enteric glial cells are more abundant than neurons in the enteric nervous system. Accumulating evidence has demonstrated that enteric glial cells share many properties with astrocytes and play pivotal roles in intestinal diseases. NDRG2 is specifically expressed in astrocytes and is involved in various diseases in the central nervous system. However, no studies have demonstrated the expression of NDRG2 in enteric glial cells. We performed immunostaining of adult mouse tissue, human colon sections, and primary enteric glial cells and the results showed that NDRG2 was widely expressed in enteric glial cells. Meanwhile, our results showed that NDRG2 was upregulated after treatment with pro-inflammatory cytokines and exposure to oxygen glucose deprivation/reoxygenation, indicating that NDRG2 might be involved in these conditions. Moreover, we determined that NDRG2 translocated to the nucleus after treatment with pro-inflammatory cytokines but not after exposure to oxygen glucose deprivation/reoxygenation. This study is the first to show the expression and distribution of NDRG2 in the enteric glia. Our results indicate that NDRG2 might be involved in the pathogenesis of enteric inflammation and ischemia/reperfusion injury. This study shows that NDRG2 might be a molecular target for enteric nervous system diseases.