||Loss of NDRG2 Expression Confers Oral Squamous Cell Carcinoma with Enhanced Metastatic Potential
2017-05 , American Association for Cancer Research
以下に掲載:Cancer Research.2017, Volume 77. Number 9. pp 2363-2374
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 PTENSTT and low levels of NDRG2expression. 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.