Inhibition of IL-6 signaling significantly reduces primary tumor growth and recurrencies in orthotopic xenograft models of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal human tumors, with radical surgical resection as the only curative treatment option. However, resection is only possible in a small fraction of patients, and about 80% of the patients develop recurrencies. PDAC development is facilitated by the cytokine interleukin-6 (IL-6), which acts via classic and trans-signaling. Both pathways are inhibited by the anti-IL-6-receptor antibody tocilizumab, whereas the fusion protein sgp130Fc specifically blocks trans-signaling. Here, we show that conservative or adjuvant therapy with both inhibitors reduces tumor growth in an orthotopic model of human Colo357 cells in SCID/bg mice. In the conservative setting, median primary tumor weight was reduced 2.4-fold for tocilizumab and 4.4-fold for sgp130Fc. sgp130Fc additionally led to a decrease in microvessel density, which was not observed with tocilizumab. In the adjuvant therapeutic setting after surgical resection of the primary tumor, treatment with tocilizumab or sgp130Fc decreased the local recurrence rate from 87.5% in the control group to 62.5 or 50%, respectively. Furthermore, the median weight of the local recurrent tumors was clearly diminished, and both inhibitors reduced the number of distant metastases. A significant reduction of tumor weight and metastases-comparable to gemcitabine treatment-was also observed with both inhibitors in another model using the poorly differentiated PancTuI cells. Our findings demonstrate the inhibition of IL-6 as a new treatment option in PDAC.

Interleukin-6: a villain in the drama of pancreatic cancer development and progression.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with a poor prognosis and little treatment options. The development and progression of the disease is fostered by inflammatory cells and cytokines. One of these cytokines is interleukin-6 (IL-6), which plays an important role in a wide range of biologic activities. DATA SOURCES: A systematic search of PubMed was performed to identify relevant studies using key words such as interleukin-6, inflammatory cytokines, inflammation and pancreatic cancer or PDAC. Articles related to IL-6 and pancreatic cancer were systematically reviewed. RESULTS: IL-6 is elevated in the serum of pancreatic cancer patients and correlates with cachexia, advanced tumor stage and poor survival. Its expression is enhanced by hypoxia and proteins involved in pancreatic cancer development like Kras, mesothelin or ZIP4. IL-6 in turn contributes to the generation of a pro-tumorigenic microenvironment and is probably involved in angiogenesis and metastasis. In experimental mouse models of PDAC, IL-6 was important for the development and progression of precursor lesions. CONCLUSION: IL-6 emerges as a key player in pancreatic cancer development and progression, and hence should be considered as a new therapeutic target.

Epicatechin gallate and catechin gallate are superior to epigallocatechin gallate in growth suppression and anti-inflammatory activities in pancreatic tumor cells.

Green tea catechins are considered as possible cancer preventive agents for several cancer types but little is known regarding their effects on pancreatic cancer cells. The best studied catechin and the major polyphenol present in green tea is epigallocatechin gallate (EGCG). In the present study, we investigated the in vitro anti-tumoral properties of EGCG on human pancreatic ductal adenocarcinoma (PDAC) cells PancTu-I, Panc1, Panc89 and BxPC3 in comparison with the effects of two minor components of green tea catechins, catechin gallate (CG) and epicatechin gallate (ECG). We found that all three catechins inhibited proliferation of PDAC cells in a dose- and time-dependent manner. Interestingly, CG and ECG exerted much stronger anti-proliferative effects than EGCG. Western blot analyses performed with PancTu-I cells revealed catechin-mediated modulation of cell cycle regulatory proteins (cyclins, cyclin-dependent kinases [CDK], CDK inhibitors). Again, these effects were clearly more pronounced in CG or ECG than in EGCG-treated cells. Importantly, catechins, in particular ECG, inhibited TNFα-induced activation of NF-κB and consequently secretion of pro-inflammatory and invasion promoting proteins like IL-8 and uPA. Overall, our data show that green tea catechins ECG and CG exhibit potent and much stronger anti-proliferative and anti-inflammatory activities on PDAC cells than the most studied catechin EGCG.

Preoperative risk evaluation of postoperative morbidity in IBD patients--impact of the POSSUM score.

BACKGROUND: The aim of this study was to assess the morbidity and mortality of patients undergoing surgery for inflammatory bowel disease (IBD) with special focus of the predictive value of the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) scoring system for preoperative risk adjustment of postoperative morbidity. METHODS: The operative notes and hospital files of 191 patients with IBD were analyzed. The POSSUM scoring system was used to predict morbidity rates after surgery. The physiological sub-score of the POSSUM score was analyzed with regard to its ability to predict postoperative complications. RESULTS: The overall complication rate was 27.7%, and the mortality was 0.5%. The morbidity rate predicted by POSSUM was 28.4% and the mortality rate 7.2%. The mean POSSUM-phys sub-score in patients without the major complications (anastomotic leakages, peritonitis, bleeding) was significant lower compared to patients with at least one of these complications (14.7 vs. 18.6; p < 0.001). Regarding the major complications separately, there were significant differences in the POSSUM-phys scores in patients developing a sepsis (14.1 vs. 23.4; p < 0.001) and/or a peritonitis (14.8 vs. 19.2; p = 0.05), whereas patients developing an anastomotic leakage/suture dehiscence or a postoperative bleeding did not differ significantly. CONCLUSION: POSSUM was an accurate predictor of morbidity in IBD patients and overpredicted mortality. The POSSUM-phys score is a promising instrument for identifying patients at increased risk of developing major postoperative complications after surgery for IBD.

CD95L Inhibition Impacts Gemcitabine-Mediated Effects and Non-Apoptotic Signaling of TNF-α and TRAIL in Pancreatic Tumor Cells.

Despite the potential apoptotic functions, the CD95/CD95L system can stimulate survival as well as pro-inflammatory signaling, particularly through the activation of NFκB. This holds true for the TNF/TNFR and the TRAIL/TRAILR systems. Thus, signaling pathways of these three death ligands converge, yet the specific impact of the CD95/CD95L system in this crosstalk has not been well studied. In this study, we show that gemcitabine stimulates the expression of pro-inflammatory cytokines, such as IL6 and IL8, under the influence of the CD95/CD95L system and the pharmacological inhibitor, sCD95Fc, substantially reduced the expression in two PDAC cell lines, PancTuI-luc and A818-4. The stem cell phenotype was reduced when induced upon gemcitabine as well by sCD95Fc. Moreover, TNF-α as well as TRAIL up-regulate the expression of CD95 and CD95L in both cell lines. Conversely, we detected a significant inhibitory effect of sCD95Fc on the expression of both IL8 and IL6 induced upon TNF-α and TRAIL stimulation. In vivo, CD95L inhibition reduced xeno-transplanted recurrent PDAC growth. Thus, our findings indicate that inhibition of CD95 signaling altered the chemotherapeutic effects of gemcitabine, not only by suppressing the pro-inflammatory responses that arose from the CD95L-positive tumor cells but also from the TNF-α and TRAIL signaling in a bi-lateral crosstalk manner.

TNF-alpha similarly induces IL-6 and MCP-1 in fibroblasts from colorectal liver metastases and normal liver fibroblasts.

Cancer-associated fibroblasts (CAFs) represent the predominant cell type of the neoplastic stroma of solid tumors, yet their biology and functional specificity for cancer pathogenesis remain unclear. We show here that primary CAFs from colorectal liver metastases express several inflammatory, tumor-enhancing factors, including interleukin (IL)-6 and monocyte-chemoattractant protein (MCP)-1. Both molecules were intensely induced by TNF-alpha on the transcript and protein level, whereas PDGF-BB, TGF-beta1 and EGF showed no significant effects. To verify their potential specialization for metastasis progression, CAFs were compared to fibroblasts from non-tumor liver tissue. Interestingly, these liver fibroblasts (LFs) displayed similar functions. Further analyses revealed a comparable up-regulation of intercellular adhesion molecule-1 (ICAM-1) by TNF-alpha, and of alpha-smooth muscle actin, by TGF-beta1. Moreover, the proliferation of both cell types was induced by PDGF-BB, and CAFs and LFs displayed an equivalent migration towards HT29 colon cancer cells in Boyden chamber assays. In conclusion, colorectal liver metastasis may be supported by CAFs and resident fibroblastic cells competent to generate a prometastatic microenvironment through inflammatory activation of IL-6 and MCP-1.

Imatinib mesylate inhibits proliferation and modulates cytokine expression of human cancer-associated stromal fibroblasts from colorectal metastases.

Recent data have expanded the concept that cancer-associated stromal fibroblasts (CAFs) play an important role in tumor invasion and angiogenesis. Here, we show that platelet-derived growth factor (PDGF) is a mitogen for human CAFs isolated from hepatic metastases of colorectal cancer. The tyrosine kinase inhibitor imatinib mesylate (1 microM) abrogated the PDGF-induced DNA synthesis, and furthermore counteracted an inhibitory effect of PDGF on the expression of alpha-smooth muscle actin (alpha-SMA). High-dose imatinib mesylate (10 microM) decreased the viability of CAFs in vitro independent from co-stimulation with PDGF. Interestingly, imatinib mesylate (10 microM) strikingly induced the expression of the pro-inflammatory and pro-angiogenic cytokines interleukin (IL)-6 and IL-8, and mildly stimulated the release of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Our results suggest that imatinib mesylate, due to its anti-proliferative activity, may be effective in combination with other substances for the treatment of colorectal metastasis progression.

Stromal fibroblasts in colorectal liver metastases originate from resident fibroblasts and generate an inflammatory microenvironment.

Cancer-associated stromal fibroblasts (CAFs) are the main cellular constituents of reactive stroma in primary and metastatic cancer. We analyzed phenotypical characteristics of CAFs from human colorectal liver metastases (CLMs) and their role in inflammation and cancer progression. CAFs displayed a vimentin(+), alpha-smooth-muscle actin(+), and Thy-1(+) phenotype similar to resident portal-located liver fibroblasts (LFs). We demonstrated that CLMs are inflammatory sites showing stromal expression of interleukin-8 (IL-8), a chemokine related to invasion and angiogenesis. In vitro analyses revealed a striking induction of IL-8 expression in CAFs and LFs by tumor necrosis factor-alpha (TNF-alpha). The effect of TNF-alpha on CAFs is inhibited by the nuclear factor-kappaB inhibitor parthenolide. Conditioned medium of CAFs and LFs similarly stimulated the migration of DLD-1, Colo-678, HuH7 carcinoma cells, and human umbilical vein endothelial cells in vitro. Pretreatment of CAFs with TNF-alpha increased the chemotaxis of Colo-678 colon carcinoma cells by conditioned medium of CAFs; however, blockage of IL-8 activity showed no inhibitory effect. In conclusion, these data raise the possibility that the majority of CAFs in CLM originate from resident LFs. TNF-alpha-induced up-regulation of IL-8 via nuclear factor-kappaB in CAFs is an inflammatory pathway, potentially permissive for cancer invasion that may represent a novel therapeutic target.