Functional study of the EBV encoded LMP1

Abstract

The Epstein-Barr virus encoded LMP1 is expressed in nasopharyngeal caricinoma cells. Recently, we have showed that LMP1 expression in immortalized epithelial cells could induce mitotic abnormality by downregulating RASSF1A expression. Downregulation of RASSF1A affects the stability of microtubules and induces formation of abnormal spindle. Expression of LMP1 could induce many pathologic phenotypes in cells. Expression of LMP1 induces upregulation of IL6 expression to activate STAT3 signaling which may mediate the pathologic properties of nasopharyngeal carcinoma cells. LMP1 expression in immortalized nasopharyngeal epithelial cells induces malignantly transformated phenotype including anchorage independent growth in soft agar, increase of invasive properties and activation of intracellular signaling for cell survival and anti-apoptosis. LMP1 expression also suppresses the exprssion of squamous differentitation marker, p63 and other differentation properties in immortalized epithelial cells. Recently, we have showed that LMP1 could also facilitate immortalization of primary cultures of nasopharyngeal epithelial cells. LMP1 immortalized nasopharyngeal epithelial cells have upregulated MAPK signaling pathways and overexpression of EGFR