Neue medikamentöse Therapiestrategien beim Pankreaskarzinom Einfluß von Octreotid und Tamoxifen, Vitamin A, C und E sowie des Cox-2-Inhibitors Celebrex und des 5-Lox-Inhibitors Zyflo auf das Tumorwachstum, die Lebermetastasierung und die hepatische Lipidperoxidation beim duktalen Adenokarzinom des Syrischen Hamsters

by Wenger, Frank Axel

Abstract (Summary)
At the time of diagnosis the majority of patients with ductal pancreatic cancer suffers from advanced tumor stages. Since present adjuvant therapies show strong side-effects and only decrease tumour growth in very few patients, the development of new therapeutic concepts seems urgent. In order to evaluate new therapeutic strategies we established a tumour model of N-nitrosobis-2-oxopropylamin (BOP) induced ductal pancreatic cancer in Syrian Hamster, which is equal to human cancer in morphological and biological aspects. Accordingly we increased the incidence of liver metastasis from 30-35% to 90% by diatetic modification elevating raw fat content from 3,5% zu 21,4% with important components linolenic and linol acid. Furthermore we evaluated the impact of increased raw fat content and oxidative stress, caused by nitrosamines, on intra- and extrametastatic lipidperoxidation. Evaluating the effect of the somatostatin analogue Octreotide and the estrogen antagonist Tamoxifen we observed that Tamoxifen did neither influence tumour growth nor liver metastasis while Octreotide decreased liver metastasis in single and combined therapy. Moreover Octreotide significantly decreased extrametastatic lipidperoxidation and increased intrametastatic lipidperoxidation. Probably inhibition of growth of liver metastasis was caused by these mechanisms. This effect seems not to be mediated by somatostatin receptors since we did not detect any receptors in non-metastatic hepatic tissue. However, intrametastatic increase of lipidperoxidation might directly be receptor-mediated, since we proved somatostatin receptors in liver metastasis. Therapy with Vitamine A and E decreased liver metastasis in pancreatic cancer. Biochemically activity of lipidperoxidation protective enzymes GSHPX and SOD was increased by Vitamine A, C and E while hepatic lipidperoxidation was decreased intra- and extrametastically. Furthermore we analysed the impact of selective cyclooxigenase-II- (Celebrex) and 5-lipoxygenase-inhibition (Zyflo) of eicosanoid metabolism on tumor growth in. While single therapy with Celebrex or Zyflo did not influence incidence, number or size of liver metastasis, these parameters were decreased by combined therapy. Moreover hepatic activity of lipidperoxidation protective enzymes was not increased intrametastatically by combined therapy. Thus intrametastatic lipidperoxidation increased and probably caused damage of membranes and apoptosis of metastatic cells.
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Bibliographical Information:


School:Humboldt-Universität zu Berlin

School Location:Germany

Source Type:Master's Thesis

Keywords:Lipidperoxidation Duktales Pankreaskarzinom Lebermetastasierung Octreotid Eicosanoidstoffwechselinhibition lipidperoxidation Ductal pancreatic carcinoma liver metastasis Octreotide inhibition of eicosanoid metabolism


Date of Publication:01/16/2003

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