enalapril and Pancreatic-Neoplasms

Pancreatic neuroendocrine neoplasias (pNEN) are the most common cause of death in adult patients with multiple endocrine neoplasia type 1 (MEN1). So far, only few chemopreventive strategies (e.g., with somatostatin analogues) have been evaluated for MEN1 associated pNENs. In this experimental study on 75 Men1(+/T) knockout mice, the effect of aspirin (n = 25) and an inhibitor of angiotensin-I converting enzyme (enalapril, n = 25) compared to controls (n = 25) were evaluated as single chemopreventive strategies for pNENs after 6, 9, 12, 15, and 18 months. After each study period, mice were sacrificed and the resected pancreata were evaluated by histopathological analysis, immunostaining, and real-time PCR. PNEN size and number was measured. Aspirin and enalapril lead to a pNEN size reduction of 80% (167,518 vs. 838,876 µm2, p < 0.001) and 79% (174,758 vs. 838,876 µm2, p < 0.001) compared to controls. Furthermore, aspirin and enalapril treatment resulted in a significant reduction of the number of pNENs by 33%, (p = 0.04) and 41% (p = 0.002) respectively. The apoptosis marker caspase 3 revealed a higher positive expression in pNEN of treated Men1(+/T) mice. Immunostaining of VEGF in pNEN detected a downregulation of its expression in treated Men1(+/T) mice compared to the control group. REL A transcript was significantly downregulated in 18-months treated enalapril Men1(+/T) mice, but not in aspirin-treated Men1(+/T) mice. There was no significant difference in the Ki-67 index. Using a transgenic mouse model that imitates human MEN1, this study provides first evidence that aspirin and enalapril are effective chemopreventive agents that aid in the progression of pNENs.

Topics: Animals; Aspirin; Chemoprevention; Enalapril; Mice; Mice, Knockout; Multiple Endocrine Neoplasia Type 1; Neuroendocrine Tumors; Pancreatic Neoplasms; Proto-Oncogene Proteins

There are no chemopreventive strategies for pancreatic cancer or its precursor lesions, pancreatic intraepithelial neoplasia (PanINs). Recent evidence suggests that aspirin and inhibitors of angiotensin-I converting enzyme (ACE inhibitors) have potential chemopreventive properties. In this study, we used a genetically engineered mouse model of pancreatic cancer to evaluate the chemopreventive potential of these drugs.. Drug treatment was initiated at the age of 5 weeks. LsL-Kras(G12D); Pdx1-Cre or LsL-Kras(G12D); LsL-Trp53(R172H); Pdx1-Cre transgenic mice were randomly assigned to receive either mock treatment, aspirin, enalapril, or a combination of both. After 3 and 5 months, animals were killed. The effect of aspirin and enalapril was evaluated by histopathological analyses, immunostaining, and real-time PCR.. After 3 and 5 months of treatment, enalapril and aspirin were able to significantly delay progression of mPanINs in LsL-Kras(G12D); Pdx1-Cre mice. Furthermore, development of invasive pancreatic cancer in LsL-Kras(G12D); LsL-Trp53(R172H); Pdx1-Cre transgenic mice was partially inhibited by enalapril and aspirin. Invasive pancreatic cancer was identified in 15 of 25 (60%) LsL-Kras(G12D); LsL-Trp53(R172H); Pdx1-Cre untreated control mice, but in only three of 17 (17.6%, p=0.01) mice treated with aspirin, in four of 17 (23.5%, p=0.03) in mice treated with enalapril alone, and in five of 16 (31.2%, p=0.11) mice treated with a combination of both drugs. Using real-time PCR we found a significant downregulation of the target genes VEGF and RelA demonstrating our ability to achieve effective pharmacological levels of aspirin and enalapril during pancreatic cancer formation in vivo.. Using a transgenic mouse model that imitates human pancreatic cancer, this study provides first evidence that aspirin and enalapril are effective chemopreventive agents by delaying the progression of PanINs and partially inhibiting the formation of murine pancreatic cancer. This study together supports the hypothesis that aspirin and ACE inhibitors might be a valid chemopreventive strategy.

Topics: Amylases; Angiotensin-Converting Enzyme Inhibitors; Animals; Anticarcinogenic Agents; Aspirin; Carcinoma in Situ; Carcinoma, Pancreatic Ductal; Disease Models, Animal; Disease Progression; Drug Evaluation, Preclinical; Enalapril; Gene Expression Regulation, Neoplastic; Mice; Mice, Transgenic; Neoplasm Invasiveness; NF-kappa B; Pancreatic Neoplasms; Receptor, Angiotensin, Type 1

Topics: Animals; Anticarcinogenic Agents; Aspirin; Disease Models, Animal; Drug Therapy, Combination; Enalapril; Humans; Mice; Pancreatic Neoplasms