The Study On E-Cadherin Expression In Oral Mucosa Precancer And Oral Squamous Cell Carcinoma

ObjectiveE-cadherin (E-cad) is one of the most important molecules in cell-cell adhesion and signal transduction. It is participated in the tissue morphogenesis and embryonic development and regulates major cellular processes including motility, growth, differentiation and survival. The major function as an adhesion can limit cell movement. Recently it was found that it is correlated with development and progression of carcinoma. E-cad plays an important role as a suppressor gene in suppression tumor's occourance, development and metastasis. Aberrant expression and absent of E-cad have a close correlation with carcinomas of poorly differentiation , invasion and metastasis. Precancer is a middle-phase which normal tissue evolvement to cancer, it can be found epithelial cell paraplasm by Pathological diagnoses. OLK(oral leukoplakia) is a damage mostly with white colour in oral mucosa and without other characters be defined. It is general precancer. OSCC(oral squamous cell carcinoma) is major carcinoma in oral tumor. The aim of this study is to detect the different expression of oral precancer and OSCC and its lymph node metastasis at the levels of mRNA and protein by ISH and Immunohistochemistry. And to discuss the mechanism of the transformation from oral precancer to cancer and OSCC metastasis.MethodsThe study group consisted of 70 patients, included 15 patiens with OLK, and 30 patiens with OSCC, and 10 patients with lymph node metastasis and 15 patients with normal oral mucosa, these speciments all were defined by clinical and Pathological diagnoses. Every speciment would be cut into four sections for HE staining, Immunohistochemical staining, ISH and negative contrast respectively. We studied the expression of E-cad in different tissues according to the results at the levels of protein and mRNA by ISH and IH. The results were performed for statistical analysis by the x test/Fisher's exact test. P <0.05 was considered significant.Results(l)ResultsoflH:The expression of E-cad in oral mucosa were strong membranous staining at the intercellular border; and in OLK the expression of E-cad in most cases were in cytoplasm or membran-cytoplasm staining with increasing degree of oral epithelial cell atypical hyperplasia. The expression of E-cad membranous has significant difference between OLK and normal oral mucosa. (P<0.05) In OSCC,the expression of E-cad were abnormal or absent between histological grade â…  , â…¡ and â…¢. And there were significant difference between them. (P<0.005) The tumors with lymph node metastasis showed a relatively strong normal or abnormal expression of E-cad than primary OSCC . There was no rule between primary OSCC and it's lymph node metastasis. (2)Results of ISH:The expression of E-cad were positive in 15 patients normal oral mucosa. And the expression in OLK and in OSCC were mostly same as the results of IH. In OSCC, the expression were positive correlation with their differentiated degree. There were positive expression of E-cad mRNA inlymph node metastasis the same as their protein. Conclusion:(1)The decrease and absent of membranous expression of E-cad in epithelial cells hint that there is a malignant potentials in oral mucosa epithelial cells. (2)Reducing or negtive expression of E-cad in OSCC were associated with squamous cell differentiation and invasion and metastasis of carcinoma cells. (3)The positive expression of E-cad in lymph node metastasis showed the presence of E-cad mRNA and showed it might be correlatea with the mechanism of epithelial- (EMT) and mesenchymal-epithelial transition (MET).