[Latent membrane protein-1 of EB virus and the phenotype of epithelial-mesenchymal transition and cervical lymph node metastasis in nasopharyngeal carcinoma].

Objective: To evaluate the relation of EB virus latent membrane protein-1 (LMP-1) and the phenotype of epithelial-mesenchymal transition (EMT) and cervical lymph node metastasis in nasopharyngeal carcinoma.

Method: Based on histopathology and MRI imaging, nasopharyngeal biopsy tissues from 88 patients with nasopharyngeal carcinoma were divided into 3 groups: pathologic metastasis (18), MRI metastasis(40) and without metastasis (30). The expressions of LMP-1, STAT3, Twist, E-Cadherin and Vimentin were examined immunohistochemically in biopsy tissues.

Result: LMP-1 expression was found in 35 of 88 biopsy tissues with a positive rate of 38.7%. The positive rates of LMP-1 in groups of pathologic metastasis, MRI metastasis and without metastasis were 38.9% (7/18), 47.5% (19/40) and 30.0% (9/30), respectively, and significant difference were not found among three groups. The expression of LMP-1 was positively correlated to both expressions of Twist and Vimentin (r = 0.276 and 0.282, are P < 0.01), but not to both expressions of STAT3 and E-Cadherin. The positive expressions or abnormal expression of STAT3, Twist, Vimentin and E-Cadherin were found in 57 of 88 (64.8%), 48 of 88 (54.5%), 22 of 88 (20.0%)and 53 of 88 (60.2%), respectively. Significant differences in the expression of STAT3, Twist, Vimentin and E-Cadherin were all found among groups of pathologic metastasis, MRI metastasis and without metastasis, respectively (are P < 0.05). The expression of STAT3 was positively correlated to both expressions of Twist and Vimentin (r = 0.712 and 0.316, P < 0.01).

Conclusion: EMT plays important role in cervical lymph node metastasis in nasopharyngeal carcinoma. LMP-1 may be only as one of upstream factors associated with the EMT, but not the decisive factor for cervical lymph node metastasis.