Methods and Results: All 7 tested cell lines expressed gp130 and IL-6Ralpha mRNA, 2 cell lines (Hs7667 and Capan1) expressed IL-6 mRNA in serum free condition by RT-PCR and Northern blotting. Hs766T cells were stimulated with or without cytokines. Northern blotting revealed TNFalpha and IL-1beta upregulated IL-6 mRNA, but not IL-6,
IL-8 and LIF. IL-6 did not affect cell Opaganib cost proliferation by WTS assay, but promoted cell motility and chemoinvasion significantly. To identify IL-6 expression by interaction between pancreatic carcinoma cells and fibroblasts, we used two established fibroblastic cell lines (MRC-9 and WI-38)isolated from human embryonal lung tissues. Serum free conditioned medium (CM) were collected after incubation for indicated periods. Hs766T produced CM (Hs766T-CM)induced IL-6 and IL-8 mRNA in MRC-9 and WI-38 cells. MRC-9 CM and WI-38-CM did not affect in Hs-766 T cells. Co-culture between Hs766T and MRC-9 cells induced IL-8 mRNA drastically. Conclusion: Communication of pancreatic carcinoma cells with fibroblasts
affect IL-6 expression and that could contribute to pancreatic cancer progression. RAD001 ic50 Regulation of IL-6 expression in tumor microenvironment would be important for pancreatic cancer therapy. Poster No. 153 The Anti-Angiogenic Activity of Bortezomib is Blocked by GRP-78 Secreted by Tumor Cells Johann Kern 1 , Gerold Untergasser1, Christoph Zenzmaier2, Guenther ADP ribosylation factor Gastl1, Eberhard Gunsilius1, Michael Steurer1,3 1 Tumor Biology & Angiogenesis Laboratory, Department of Internal Medicine V Innsbruck, Medical University of Innsbruck, Innsbruck, Tirol, Austria, 2 Institute for Biomedical Aging Research, Austrian Academie of Sciences, Innsbruck, Tirol, Austria, 3 Laboratory for Molecular Genetics, Department of Internal Medicine V, Medical University of Innsbruck, Innsbruck, Tirol, Austria Anti-angiogenic effects of the proteasome inhibitor bortezomib were analyzed in vivo using tumor xenografts in the chicken chorioallantoic membrane (CAM) assay. Bortezomib’s inhibitory effects on CAM vascularization
were abrogated in the presence of distinct tumor xenografts suggesting a soluble inhibitory factor secreted by tumor cells. Using size-exclusion and ion-exchange chromatography as well as mass spectroscopy. GRP-78, a chaperone protein of the unfolded protein response, normally expressed and retained in the endoplasmatic reticulum was identified as being responsible for bortezomib inhibition. In fact, a variety of bortezomib-resistant solid tumor cell lines (PC-3, HRT-18), but not bortezomib-sensitive myeloma cell lines (U266, OPM-2) were found to secrete high amounts of GRP-78. In fact, recombinant GRP-78 confered bortezomib resistance to endothelial cells and knock down of GRP-78 in PC-3 cells resulted in loss of bortezomib resistance.