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

We studied the effect of TNF-alpha stimulation on a cholangiocarcinoma cell line, CCKS1. CCKS1 expressed only one type TNF receptor, TNFR2. Treatment of CCKS1 with TNF-alpha substantially activated NFkappaB, 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-alpha-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-alpha dependent MMP-9 secretion. These results strongly suggest that TNF-alpha-TNFR2 signaling plays an important role to convert the cholangiocarcinoma cells to be more aggressive one.

Profiling of gene expression associated with hepatolithiasis by complementary DNA expression array.

By use of cDNA expression array method, we compared the expression profiles of genes in hepatolithiasis tissues with those of paired normal tissues. Expression of 1176 cancer related genes that include 33 tumor suppressor genes, 100 proto-oncogenes and 37 DNA damage repair genes were examined in this study. We found that expression of tumor suppressor genes and proto-oncogenes was systemically activated in hepatholithiasis tissues, suggesting that expression of genes controlling cell growth becomes unstable in liver lobe of hepatolithiasis. In contrast, expression of DNA damage repair genes were not activated but rather remained unchanged in hepatholithiasis tissues, suggesting that repair process is not strongly activated but rather impaired in hepatholithiasis tissues.