Metastasis consists of complex cascades and a lot of factors are involved in each step of metastasis. In recent studies, the role of epithelial-mesenchymal transition (EMT) in metastasis is suggested. EMT has a feature of epithelial cells conversing into mesenchymal cells morphologically and phenotypically, is a characteristic of malignant and metastatic cells in most cancer. The mesenchymal cells usually show more malignant phenotype, including invasion and metastasis. EMT can play an important role in metastasis of oral squamous cell carcinoma (OSCC). Although the role of Snail, slug, other transcriptional factors and E-cadherin are well known in human cancers, there are a few studies on N-cadherin and Twist expression in OSCC. The present study was aimed to analyze the expression of N-cadherin and Twist protein in OSCC from Korean patients. The immunohistochemical stain was performed using 58 primary OSCCs and 6 metastatic OSCCs, and the correlation between the expression of these proteins and clinicopathological parameters of OSCC patients was analyzed. The expression rate of high expression of N-cadherin was observed in 70.4% and Twist in 87.3% of OSCC. The expression of N-cadherin in metastatic OSCC increased than in corresponding primary OSCC (p<0.05). The spearman correlation coefficiency between N-cadherin and Twist was calculated as 0.228. The clinical factors such as lymph node metastasis and survival showed statistically significant correlation between N-cadherin expression. The expression of Twist was correlated with recurrence. In conclusion, the authors suggest that N-cadherin may play an important role in malignant behaviour of OSCC and can be considered as prognostic indicator of OSCC.

Ⅰ. Introduction
 Ⅱ. MATERIALS AND METHODS
  1. Patients and tissue samples
  2. The clinicopathological characteristics ofOSCC patients
  3. H/E stain and immunohistochemical stain
  4. Evaluation of immunohistochemical stain
  5. Statistical Analysis
 III. Result
  1. The characteristics of OSCC patients
  2. N-cadherin and Twist Expression in OSCCpatients
  3. Correlation between N-cadherin expressionand the clinicopathological parameters ofOSCC patients
  4. Relationship between N-cadherin and Twistexpression and survival months
 IV. Discussion
 Ⅳ. References

• 이창식(Department of Oral Pathology, School of Dentistry, Yangsan Campus of Pusan National University) | Chang Sik Lee
• 유미현(Department of Oral Pathology, School of Dentistry, Yangsan Campus of Pusan National University) | Mi Heon Ryu
• 김진(Department of Oral Pathology, Yonsei University College of Dentistry) | Jin Kim
• 한혜연(Department of Oral Pathology, School of Dentistry, Yangsan Campus of Pusan National University) | Hye Yeon Han
• 이창훈(Department of Pathology, Pusan National University School of Medicine) | Chang Hoon Lee
• 박혜련(Department of Oral Pathology, School of Dentistry, Yangsan Campus of Pusan National University) | Hae Ryoun Park
• 박봉수(Department of Oral Anatomy, School of Dentistry, Yangsan Campus of Pusan National University) | Bong Soo Park correspondence