Tumor necrosis factor α promotes invasiveness of cholangiocarcinoma cells via its receptor, TNFR2

We studied the effect of TNF-α stimulation on a cholangiocarcinoma cell line, CCKS1. CCKS1 expressed only one type TNF receptor, TNFR2. Treatment of CCKS1 with TNF-α substantially activated NFκB, MAPK and Akt signalings which in turn activated matrix metalloproteinase-9 (MMP-9) secretion and in vitro invasiveness of CCKS1. Pretreatment of cells with anti-TNFR2 neutralizing antibody inhibited the TNF-α-dependent signaling and MMP-9 secretion and subsequently blocked invasion in vitro. Moreover, an inhibitor for matrix metalloproteinase, Galardin, suppressed the invasion in a dose-dependent manner. Similarly, pharmacological inhibition of signaling clearly suppressed the TNF-α dependent MMP-9 secretion. These results strongly suggest that TNF-α-TNFR2 signaling plays an important role to convert the cholangiocarcinoma cells to be more aggressive one.