Induction of c-Met proto-oncogene by Epstein-Barr virus latent membrane protein-1 and the correlation with cervical lymph node metastasis of nasopharyngeal carcinoma

Am J Pathol. 2001 Jul;159(1):27-33. doi: 10.1016/S0002-9440(10)61669-0.

Abstract

Nasopharyngeal carcinoma (NPC) is distinctive in head and neck carcinomas for its close association with Epstein-Barr virus and its highly metastatic nature. Up-regulation of cell motility is essential for enhancement of metastatic potential. The expression of c-Met proto-oncogene, a high-affinity receptor for hepatocyte growth factor/scatter factor, has been reported to correlate with metastatic ability of the tumor cell. We observed close association of c-Met expression with cervical lymph node metastasis (P = 0.0272) in 39 NPC specimens studied immunohistochemically. Epstein-Barr virus-encoding latent membrane protein-1 (LMP-1) is a primary oncogene and is suggested to enhance the metastatic property of NPC. Previously, we reported that LMP-1 enhanced the motility of Madin-Darby canine kidney (MDCK) epithelial cells that was mediated by activation of Ets-1 transcription factor. Therefore, we examined the interrelationships of LMP-1, Ets-1, and c-Met. In immunohistochemical studies, the expression of LMP-1, Ets-1, and c-Met correlated significantly with each other in NPC (LMP-1 versus Ets-1, P < 0.0001; Ets-1 versus c-Met, P = 0.0012; LMP-1 versus Met, P = 0.0005). Transfection of LMP-1-expressing plasmid in MDCK cells induced c-Met protein expression. The c-Met protein was also induced by Ets-1 expression, and induction of c-Met by LMP-1 was suppressed by introducing a dominant-negative form of Ets-1 in LMP-1-expressing MDCK cells. These results suggest that LMP-1 induces c-Met through the activation of Ets-1, which may contribute in part to the highly metastatic potential of NPC.

MeSH terms

  • Animals
  • Cell Line
  • Dogs
  • Female
  • Gene Expression Regulation*
  • Humans
  • Immunohistochemistry
  • Lymphatic Metastasis / pathology*
  • Male
  • Middle Aged
  • Nasopharyngeal Neoplasms / genetics*
  • Nasopharyngeal Neoplasms / secondary*
  • Neck
  • Proto-Oncogene Mas
  • Proto-Oncogene Protein c-ets-1
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-ets
  • Proto-Oncogene Proteins c-met / genetics*
  • Proto-Oncogene Proteins c-met / metabolism
  • Transcription Factors / metabolism
  • Transfection
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / metabolism
  • Viral Matrix Proteins / pharmacology*

Substances

  • EBV-associated membrane antigen, Epstein-Barr virus
  • ETS1 protein, human
  • MAS1 protein, human
  • Proto-Oncogene Mas
  • Proto-Oncogene Protein c-ets-1
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Transcription Factors
  • Viral Matrix Proteins
  • Proto-Oncogene Proteins c-met