Effect of Epstein-Barr virus-encoded latent membrane protein 1 on β-catenin transcriptional activity and expression in nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the contribution of latent membrane protein (LMP)1 to nasopharyngeal carcinogenesis via Wnt/β-catenin signal pathway.</p><p><b>METHODS</b>The recombinant plasmid pHA2-LMP1 was constructed; immunofluorescence staining, Dual-Luciferase Reporter Assay, Western blot and immunohistochemistry staining were used to study the effect of LMP1 on the transcriptional activity and expression of β-catenin.</p><p><b>RESULTS</b>(1) Abnormal expression of β-catenin was obtained in 38 cases (50.7%, 38/75), LMP1 expression was obtained in 38 cases (50.7%, 38/75). There was significantly positive correlation between LMP1 expression and abnormal expression of β-catenin in nasopharyngeal carcinoma tissue (P = 0.008). (2) The expression of β-catenin in nuclei of NPC cell line CNE1 and CNE2 transfected with pHA2-LMP1 plasmid dramatically increased, and the expression was remarkable in poorly-differentiated NPC cell line CNE2 than that of well-differentiated CNE1 cells. (3) LMP1 expression dramatically increased the transcriptional activity of β-catenin in CNE1 and CNE2 cells transfected with pHA2-LMP1 and was in a time-dependent. The transcriptional activity of β-catenin was higher in poorly-defferentiated cell line CNE2 than that of well-differentiated NPC cell line CNE1. (4) LMP1 expression did not affect the total protein expression level of β-catenin in both CNE1 and CNE2 cell lines.</p><p><b>CONCLUSION</b>EB virus-encoded LMP1 may be involved in the pathogenesis of NPC via β-catenin signal pathway.</p>

Analysis of Epstein-Barr virus BamH I "f" variant in nodal metastasis of nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the Epstein-Barr virus (EBV) BamH I "f" variant in primary nasopharyngeal carcinoma (NPC) and its metastases in lymph nodes (LN).</p><p><b>METHODS</b>In situ hybridization was used to detect EBV-encoded small RNA (EBER) expression in 21 paired paraffin-embedded tissue from primary NPC and their lymph node metastases and 22 primary NPC without lymph node metastasis. PCR and restriction fragment length polymorphism (RFLP) assay were used to detect EBV BamH I "f" variant in all cases of NPCs, lymph node metastases and 50 cases of chronic inflammation of nasopharynx from Canton.</p><p><b>RESULTS</b>All cases of NPCs and their lymph node metastases showed EBER expression, indicating a high EBV-positive rate in Cantonese NPC patients. EBV BamH I "f" variant was found in 11 cases (52.4%, 11/21) of primary NPCs with LN metastasis, 12 cases (57.1%, 12/21) of the LN metastases, and 18 cases (81.8%, 18/22) of primary NPCs without LN metastasis. However, of the 50 cases of chronic inflammation of nasopharynx, only one case (2.1%, 1/47) demonstrated BamH I "f" variant. The frequency of BamH I "f" variant in NPC was therefore dramatically higher than that in chronic inflammation of nasopharynx. It is of note that atypical hyperplasia was observed in a few epithelial cells from the case of chronic inflammation of nasopharynx expressing BamH I "f" variant.</p><p><b>CONCLUSIONS</b>The frequency of EBV BamH I "f" variant in NPC is significantly higher than that in chronic inflammation of nasopharynx. It is the first demonstration that the BamH I "f" variant is also present in the LN metastases of NPC. The frequency of BamH I "f" variant in metastatic NPC of the lymph node is almost equal to that of primary NPCs.</p>