Methods: FOXM1 expression in 52 clinical HCC tissues was examined both by immunohistochemistry and Western blot; Chromatin Immunoprecipitation (ChIP) was performed to examine the possible occupancy of the AFP promoter by FOXM1; Cytotoxicity of Thiostrepton were tested in HepG2 and HepG2.2.15 cell lines; cell cycle profiles were assessed by flow cytometry and the possible molecular targets were explored. Results: Up-regulation of FOXM1 was confirmed in 69.2% (36/52) of HCC tissues. Clinicopathologically, FOXM1 up-regulation was associated with metastasis (P=0.039). More importantly, a significant positive

correlation was observed RAD001 order between either tissue AFP mRNA or plasma AFP concentration and tissue FOXM1 expression levels Serine Protease inhibitor before surgery (r=0.3, p=0.03; r=0.332, p=0.016; respectively). Meanwhile, a significant positive correlation between tissue AFP mRNA and pre-operative serum AFP level was demonstrated by the spearman rank correlation test (r=0.574, P<0.01). Both FoxM1 interference and Thiostrepton treatment led to significant reduction of AFP secretion in cell culture media. Moreover, CHIP assay confirmed that FOXM1 can bind to eight Forkhead response elements (FHREs) located at the proximal region of the AFP promoter. In addition, Thiostrepton dramatically reduced

FOXM1 expression in HCC cells, leading to cell cycle blockade at G1/S transition, concomitant with down-regulated CyclinD1, CDK2, CDK4 and SKP2 expression, and significantly induced FOXO3A expression. Conclusions: These data suggested that FOXM1 expression is closely correlated with both in vitro and in vivo AFP production possibly through its transcriptional regulation of the AFP promoter. Thiostrepton may specifically target FOXM1 to induce cytotoxic effect and

could be potentially developed as a novel anticancer drug against HCC. Disclosures: The following people have nothing to disclose: Huang S. Feng, Ai J. Gang, Wu Yan, Chen J. Juan, Liping Zhang Background and Aims: Liver is the most common site of metastasis for pancreatic cancer. In tumor microenvironment, 3-mercaptopyruvate sulfurtransferase stellate cells influence growth and metastasis of cancer by multiple mechanisms, including regulating extracellular matrix turnover. Sphingosine 1-phosphate (S1P) signaling has been implicated in tumorigenesis and metastasis in many cancers; however, its role in the metastasis of pancreatic cancer cells to the liver, remains unexplored. We hypothesized that S1P activates stellate cells to release paracrine factors that promote tumor cell migration and invasion that promote metastatic growth. Methods: Immortalized human or mouse stellate cells were stimulated with S1P (0.5–5 μM) or vehicle. S1 P1 or S1P2 receptor was disrupted by shRNA, siRNA, or pharmacological inhibitors. Stellate cell conditioned media was used to measure pancreatic cancer cell (PANC1) migration and invasion in Boy-den chamber and Transwell assays.