es to invasive migration of LCLs, too. However, canonical NF ��B signaling also affects the e pression of other proteins than Fascin that could con tribute to cellular motility as well. Yet, selective repression of Fascin in LMP1 e pressing Jurkat T lymphocytes re vealed that in this cell type Fascin contributes to invasive migration. As yet, it was known that LMP1 is a potent regulator of cellular migration and invasion since LMP1 is capable of inducing a wide range of cellular factors in volved in tumor metastasis. Both LMP1 mediated transcriptional, posttranscriptional and posttranslational regulation of cellular targets could contribute to the capacity of LMP1 to promote spreading of tumor cells LMP1 causes loss of junctional plakoglobin in naso pharyngeal carcinoma cells and initiates a cadherin switch.

LMP1 upregulates decoy receptor 3, a member of the TNFR superfamily, which enhances Cilengitide NPC cell migration and invasion. LMP1 down regulates E cadherin gene e pression and induces cell migration activity by using cellular DNA methylation machinery. In NPC cells, LMP1 increases phos phorylation of the membrane cross linker ezrin through a protein kinase C pathway. Recruitment of ezrin to the cell membrane linked to F actin and CD44 is a process required for LMP1 stimulated cell motility and invasion of NPC cells. We now show that LMP1 can also in duce the actin bundling Fascin, which is strongly associ ated with migration and invasion in many types of cancer.

In contrast to previous studies, which mainly fo cused on cells of epithelial origin and NPC, we now show in T lymphoid cells that LMP1 is also import ant for invasive migration, whereas it seems to be dispens able for attachment of invaded cells. Beyond that our data highlight for the first time an important role of Fascin in LMP1 mediated invasive migration. Interestingly, LMP1s capacity to enhance migration is regulated by PI3K Akt and also by I��B dependent canonical NF ��B signaling in NPC cells. Thus, LMP1 mediated induction of NF ��B also appears to contribute to LMP1 induced cell migra tion in lymphocytes, in particular by regulation of Fascin. Activation of the NF ��B pathway is linked to LMP1 induced immortalization of primary B lymphocytes. Al though signaling via CTAR2 mainly induces canonical NF ��B signaling and production of p100, CTAR2 is not sufficient for transformation in the absence of CTAR1.

In contrast, CTAR1 is only a weak activator of NF ��B and induces noncanonical NF ��B signaling resulting in processing of p100, but is sufficient for initial transform ation. We show by three approaches that canonical NF ��B signals are important for LMP1 mediated Fascin induction A mutation of CTAR2 that is defective in NF ��B signaling failed to induce Fascin, Use of a super repressor of NF ��B blocked LMP1 mediated Fascin induction, and chemical block of IKKB reduced canonical NF ��B signaling and Fascin e pression in both LMP1 transfected and LMP1 transformed lymphocytes. Earlier studies hav