[Gemcitabine in Combination with Cisplatin in Patients with Unresectable Advanced or Recurrent Biliary Tract Cancer--A Multicenter Prospective Observational Study in Fukuoka].

The standard chemotherapy for the treatment of unresectable advanced and recurrent biliary tract cancers is considered gemcitabine plus cisplatin (GC) on the basis of favorable results reported in the ABC-02 study from the UK and the BT22 study from Japan. However, the GC cohort of the BT22 study consisted of only 42 patients, and we considered it necessary to confirm the effectiveness and safety of GC chemotherapy in a multicenter prospective observational study in Fukuoka. Thirty-seven patients were enrolled in this study, including two patients with recurrent disease. The median patient age was 67.5 years (range, 43-84 years). Twelve patients had intrahepatic cholangiocarcinoma, 13 patients had extrahepatic cholangiocarcinoma, and 12 patients had gallbladder cancer. The median survival time (MST) was 14.9 months, the 1-year survival rate was 54.5%, and the median progression free survival (PFS) was 7.7 months. No chemotherapy-related deaths occurred, and Grade 3/4 adverse events were mainly hematological events including leucopenia in 13 (35.1%) patients and neutropenia in 12 (32.4%). The MST, 1-year survival rate, median PFS, and rate of Grade 3/4 adverse events in our study were similar to those of the BT22 study. In conclusion, this multicenter prospective observational study confirms the effectiveness and safety of GC chemotherapy for the treatment of unresectable advanced and recurrent biliary tract cancers.

The role of oxysterol binding protein-related protein 5 in pancreatic cancer.

The expression of oxysterol binding protein-related protein (ORP) 5 is related to invasion and a poor prognosis in pancreatic cancer patients. ORP5 induced the expression of sterol response element binding protein (SREBP) 2 and activated the downstream gene of sterol response element. ChIP using SREBP2 antibody revealed that histone deacetylase 5 (HDAC5) was one of the downstream genes of SREBP2. The effect of HMG-CoA reductase inhibitors (statins) were analyzed according to the expression level of ORP5. The invasion rate and growth was suppressed in cells that strongly expressed ORP5 in a time- and dose-dependent manner, but had less effect in cells weakly expressing ORP5, suggesting that when the potential of invasion and growth relies on the cholesterol synthesis pathway, it becomes sensitive to HMG-CoA reductase inhibitor. Furthermore, HDAC inhibitor, tricostatin A, induced the expression of phosphatase and tensin homolog as well when ORP5 was suppressed or the cells were treated with statin. Treatment with both statin and tricostatin A showed a synergistic antitumor effect in cells that highly expressed ORP5. Therefore, in some pancreatic cancers, continuous ORP5 expression enhances the cholesterol synthesis pathway and this signal transduction regulates phosphatase and tensin homolog through HDAC5 expression. This is the first report to detail how the signal transduction of cholesterol synthesis is related to cancer invasion and why statins can suppress invasion and growth.