Decreased expression of E-cadherin and increased invasive capacity in EBV-LMP-transfected human epithelial and murine adenocarcinoma cells.

The EBV-encoded membrane protein LMP is one of 9 viral proteins regularly expressed in virally immortalized B lymphocytes. It is expressed in EBV-carrying lymphoblastoid cell lines of normal origin and in the majority of the poorly differentiated nasopharyngeal carcinomas, but not in Burkitt lymphomas. LMP has been reported to transform rodent fibroblasts, to inhibit epithelial differentiation and to alter morphology and cytokeratin expression in an in vitro immortalized human keratinocyte cell-line, RHEK-I. We now report that an LMP-transfected mouse mammary carcinoma line, SHG, exhibits a similar morphological change to that previously described in the LMP-transfected RHEK-I. In the LMP-transfected RHEK-I and SHG cells, we observed a decreased expression of the calcium-dependent adhesion molecule E-cadherin. The LMP-transfected RHEK-I cells were capable of invading type-I collagen gels while the control cells were not. The LMP-transfected SHG cells showed a significantly higher invasive capacity than the original cell line.