10919

EHMT2

Head and neck squamous cell carcinoma (HNSCC) is a particularly aggressive cancer with poor prognosis, largely due to lymph node metastasis and local recurrence. Emerging evidence suggests that epithelial-to-mesenchymal transition (EMT) is important for cancer metastasis, and correlated with increased cancer stem cells (CSCs) characteristics. However, the mechanisms underlying metastasis to lymph nodes in HNSCC is poorly defined. In this study, we show that E-cadherin repression correlates with cancer metastasis and poor prognosis in HNSCC. We found that G9a, a histone methyltransferase, interacts with Snail and mediates Snail-induced transcriptional repression of E-cadherin and EMT, through methylation of histone H3 lysine-9 (H3K9). Moreover, G9a is required for both lymph node-related metastasis and TGF-beta-induced EMT in HNSCC cells since knockdown of G9a reversed EMT, inhibited cell migration and tumorsphere formation, and suppressed the expression of CSC markers. Our study demonstrates that the G9a protein is essential for the induction of EMT and CSC-like properties in HNSCC. Thus, targeting the G9a-Snail axis may represent a novel strategy for treatment of metastatic HNSCC.

Special AT-rich sequence-binding protein 2 (SATB2) is a transcription factor, which plays an important role in transcriptional regulation and chromatin recombinant by combining with matrix attachment regions. More evidence shows that SATB2 is involved in progression of breast cancer, head and neck squamous cell carcinomas and osteosarcoma. However, the role of SATB2 in cancer initiation and progression is still not well understood. Our study identified that decreased expression of SATB2 was correlated with tumor progression and poor prognosis in non-small cell lung cancer (NSCLC) patients. Furthermore, SATB2 suppressed lung cancer cell invasion and metastasis and regulated the expression of EMT-related proteins and histone methylation by G9a. In summary, SATB2 may act as a tumor suppressor gene in NSCLC.