Knut Ketterer

Technische Universität München, München, Bavaria, Germany

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Publications (14)63.98 Total impact

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    ABSTRACT: Dramatic weight loss is an often underestimated symptom in pancreatic cancer patients. Cachexia- defined as an unintended loss of stable weight exceeding 10%--is present in up to 80% of patients with cancer of the upper gastrointestinal tract, and has a significant influence on survival. The aim of the study was to show the multiple systemic effects of cachexia in pancreatic cancer patients, in terms of resection rate, effects on pulmonary function, amount of fat and muscle tissue, as well as changes in laboratory parameters. In patients with pancreatic cancer, clinical appearance was documented, including the amount of weight loss. Laboratory parameters and lung-function tests were evaluated, and the thickness of muscle and fat tissue was measured with computed tomography scans. Statistical analysis, including multivariate analysis, was performed using SPSS software. Survival curves were calculated using Kaplan-Meier analysis and the log-rank test. To test for significant differences between the examined groups we used Student's t-test and the Mann-Whitney U test. Significance was defined as p < 0.05. Of 198 patients with a ductal adenocarcinoma of the pancreas, 70% were suffering from weight loss when they presented for operation, and in 40% weight loss exceeded 10% of the stable weight. In patients with cachexia, metastases were diagnosed significantly more often (47% vs. 24%, P < 0.001), leading to a significantly reduced resection rate in these patients. Patients with cachexia had significantly reduced fat tissue amounts. Hence, dramatic weight loss in a patient with pancreatic cancer may be a hint of a more progressed or more aggressive tumour. Pancreatic cancer patients with cachexia had a higher rate of more progressed tumour stages and a worse nutritional status. Furthermore, patients with cachexia had an impaired lung function and a reduction in fat tissue. Patients with pancreatic cancer and cachexia had significantly reduced survival. If weight loss exceeded 5% there was a significantly reduced resection rate to detect, but the changes were significantly more substantial if weight loss was 10% or more. We propose that a weight loss of 10% be defined as significant in pancreatic cancer.
    BMC Cancer 07/2009; 9:255. · 3.33 Impact Factor
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    ABSTRACT: Cachexia is a devastating process especially in pancreatic cancer patients and contributes to their poor survival. We attempted to clarify the pathological and molecular changes that occur in the liver during the development of cachexia. Using immunohistochemistry we investigated the infiltration of inflammatory mononuclear cells in liver biopsies of pancreatic cancer patients with or without cachexia, and the potential relevance of the cells for the nutritional and inflammatory status. Additionally, these findings were compared with the patients' clinical parameters. We found a significantly higher amount of CD68 immunoreactive macrophages in liver cross sections of patients with pancreatic cancer and cachexia. The number of CD68-positive macrophages was significantly inversely correlated with the nutritional status. Additionally, in these CD68-positive areas a significant increase in IL-6 and IL-1 immunoreactive cells was localized. Moreover, we found significantly increased areas of CD68-positive macrophages in liver biopsies of patients with a more dedifferentiated (aggressive) grading of the tumor. In conclusion, these results suggest that a crucial interaction between the tumor, PBMCs, and the liver may play a central role in the development and regulation of cachexia. Furthermore, pancreatic cancer may be able to alter systemic organ function even without obvious metastatic disease.
    Oncology Reports 03/2009; 21(2):363-9. · 2.30 Impact Factor
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    ABSTRACT: Neuromedin U (NmU) is a bioactive peptide, ubiquitously expressed in the gastrointestinal tract. Here, we analyzed the role of NmU in pancreatic ductal adenocarcinoma (PDAC) pathogenesis. NmU and NmU receptor-2 mRNA were significantly overexpressed in PDAC and in metastatic tissues. NmU and NmU receptor-2 were localized predominantly in cancer cells. NmU serum levels decreased after tumor resection. Although NmU exerted no effects on cancer cell proliferation, it induced c-Met and a trend towards increased invasiveness as well as an increased hepatocyte growth factor (HGF)-mediated scattering. Thus, NmU may be involved in the HGF-c-Met paracrine loop regulating cell migration, invasiveness and dissemination of PDAC.
    Cancer letters 01/2009; 277(1):72-81. · 4.86 Impact Factor
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    ABSTRACT: In chronic pancreatitis (CP), both the progressive loss of acinar parenchyma and aggressive fibro-inflammatory reactions ultimately lead to irreversible organ destruction. Dying cells are normally removed by macrophages and elimination is associated with anti-inflammatory cytokine switch. We investigated whether defective clearance of damaged acini by macrophages such as compromised phagocytosis or altered cytokine reaction occurs in CP and thus represents a causative link between acinar loss and fibro-inflammation. In a checkerboard-like co-culture system, we assessed normal and CP macrophages for their phagocytic and cytokine responses to dying pancreatic acinar cells of normal or CP origin by FACS, confocal microscopy, QRT-PCR, and ELISA. In CP, phagocytosis of apoptotic acini by macrophages was not impaired; however, the associated cytokine responses were gradually perturbed. Most interestingly, only normal acini suppressed TGFbeta1 expression and accumulation specifically in normal macrophage cultures, while CP acini lost this ability. Both types of apoptotic acini induced pro-inflammatory cytokine bursts of varying strength in both types of macrophages; however, the most significant difference (more than 50-fold higher expression of IL-1beta, IL-6, and IL-8) was evident between CP/CP and normal/normal combinations, indicating that acinar and macrophage alterations synergistically lead to the ultimate CP-specific bias. In combination with in situ data comparing circulating inflammatory cells to pancreatic resident ones, our results indicate that cytokine expression in inflammatory cells undergoes spatiotemporal modulation, most likely through a successive interplay of acinar, stromal, and circulating factors. Thus, clearance of injured pancreatic acini by macrophages is associated with a unique cytokine reaction which may constitute a basis for progression of SAPE (sentinel acute pancreatitis event) to the irreversible fibro-inflammation in CP.
    The Journal of Pathology 07/2008; 215(2):195-203. · 7.59 Impact Factor
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    ABSTRACT: The expression and localization of FXYD domain containing ion transport regulator 3 (FXYD3), a transmembrane protein that acts as a chloride channel or chloride channel regulator, was analyzed in pancreatic tissues derived from donors and patients suffering from chronic pancreatitis (CP) or pancreatic ductal adenocarcinoma (PDAC) as well as in pancreatic cancer cells using QRT-PCR, laser-capture microdissection and microarray analysis, in situ hybridization and immunohistochemistry. FXYD3 antisense expressing T3M4 pancreatic cancer cells were generated and compared to control cells using anchorage-dependent and independent growth assays, and xenotransplantation into nude mice. FXYD3 mRNA levels were 3.4-fold increased in PDAC tissues compared to donor specimens (p = 0.006), and 3.9-fold increased in microdissected cancer cells compared to normal pancreatic ductal cells (p = 0.02). FXYD3 was localized in the tubular complexes and PanIN lesions of both CP and PDAC, as well as in pancreatic cancer cells. Downregulation of FXYD3 by stable antisense transfection increased significantly the doubling time of T3M4 pancreatic cancer cells from 44 +/- 2 hr to 55 +/- 12 hr (p = 0.02). Nude mice transplanted with antisense transfected cells displayed a significant increase in tumor doubling time from 3.3 days +/- 1.0 to 4.3 days +/- 0.43 (p = 0.058). Anchorage-independent growth and sensitivity to 5-fluorouracil, gemcitabine and cisplatin as well as to MgCl(2) were not dependent on the level of FXYD3 expression. In conclusion, overexpression of FXYD3 in pancreatic cancer may contribute to the proliferative activity of this malignancy.
    International Journal of Cancer 02/2006; 118(1):43-54. · 6.20 Impact Factor
  • Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 07/2005; 446(6):680-1. · 2.68 Impact Factor
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    ABSTRACT: Altered expression of apoptosis-regulating genes plays an important role in the aggressive growth behavior and chemoresistance of pancreatic ductal adenocarcinoma. In the present study, the hypoxia-inducible proapoptotic gene, BNIP3, was analysed in terms of expression, effect on patient survival, and chemo-responsiveness in pancreatic cancer cell lines. cDNA microarray, real-time light cycler quantitative polymerase chain reaction, laser-capture microdissection, and immunohistochemistry analyses were used to evaluate BNIP3 expression in normal and diseased pancreatic specimens. Modulation of BNIP3 expression was achieved using specific siRNA molecules. The effect of chemotherapeutic agents on pancreatic cancer cells was assessed utilizing 3-(4,5-methylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromide assays. BNIP3 mRNA levels were 3.0- and 6.3-fold lower in chronic pancreatitis and pancreatic cancer compared to the normal pancreas, respectively. Microdissection analysis confirmed the reduction of BNIP3 expression in pancreatic cancer cells compared to normal duct cells. By immunohistochemistry, BNIP3 was predominantly expressed in the acinar cells of the normal and diseased pancreas. Interestingly, while BNIP3 was undetectable in the cancer cells of 59% of the cases, 75-100% of PanIN2/3 lesions displayed BNIP3 immunoreactivity. Loss of BNIP3 expression correlated with poorer survival of patients (8 vs 14 months for BNIP3 negative vs positive tumors). Hypoxia induced BNIP3 expression in four out of eight pancreatic cancer cell lines, while it was absent under normoxic and hypoxic conditions in the remaining four. Downregulation of BNIP3 resulted in increased resistance to 5-fluoro-uracil and gemcitabine. In conclusion, loss of BNIP3 expression occurs late in pancreatic cancer, contributes to resistance to chemotherapy, and correlates with a worsened prognosis.
    Oncogene 07/2005; 24(27):4421-32. · 8.56 Impact Factor
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    ABSTRACT: 14-3-3sigma belongs to the 14-3-3 family of proteins, which are involved in the modulation of diverse signal transduction pathways. Loss of 14-3-3sigma expression has been observed in a number of human cancers, suggesting that it may have a role as a tumor suppressor gene. The aim of the study was to investigate the expression and the functional role of 14-3-3sigma in pancreatic ductal adenocarcinoma (PDAC). Expression of 14-3-3sigma was analyzed using laser capture microdissection (LCM), quantitative real-time-PCR (QRT-PCR), DNA arrays, immunohistochemistry and western blot analysis. The role of 14-3-3sigma in apoptosis and cell cycle regulation was evaluated by western blotting, immunoprecipitation and FACS analysis. By QRT-PCR, 14-3-3sigma mRNA levels were 54-fold increased in pancreatic adenocarcinoma in comparison with normal pancreatic samples and localized in pancreatic cancer cells as determined by LCM. In pancreatic cancer cells, the degree of 14-3-3sigma expression was not decisive for the maintenance of G(2)/M cell cycle checkpoint or induction of apoptosis. Responses to radiation or apoptosis-inducing agents were neither accompanied by a significant 14-3-3sigma accumulation nor by a change in association of 14-3-3sigma with cdc2, bad and bax. In conclusion, the marked over-expression of 14-3-3sigma in PADC together with multiple known genetic and epigenetic alterations of potential 14-3-3sigma interacting partners suggests an important role of aberrant 14-3-3sigma downstream signaling in pancreatic cancer.
    Carcinogenesis 10/2004; 25(9):1575-85. · 5.64 Impact Factor
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    ABSTRACT: Pancreatic cancer is an aggressive malignancy that exhibits a number of genetic and epigenetic alterations. Indian hedgehog (Ihh) and its 2 signaling receptors, patched (Ptc) and smoothened (Smo), are involved in pancreatic development and regulation of beta-cell function as well as in certain human tumors. In the current study, we analyzed the expression, distribution and function of Ihh and its receptors in pancreatic cancer. Quantitative RT-PCR and immunohistochemistry were utilized to analyze the expression, localization and transcriptional regulation of Ihh, Ptc and Smo. The effects of inhibition and stimulation of the hedgehog signaling pathway on pancreatic cancer cell growth were examined by the MTT cell growth assay. By quantitative RT-PCR, Ihh, Ptc and Smo mRNA levels were increased 35-, 1.2- and 1.6-fold, respectively, in pancreatic cancer tissues in comparison to normal pancreatic tissues. By immunohistochemistry, Ihh, Ptc and Smo were expressed in the islet cells of normal and cancerous tissues and in pancreatic cancer cells. The growth of pancreatic cancer cells was dose-dependently inhibited by the hedgehog antagonist cyclopamine through G0/G1 arrest. In contrast, Ihh agonists exhibited no significant effect on pancreatic cancer cell growth. TGF-beta1 repressed Ihh transcription in a TGF-beta1-responsive pancreatic cancer cell line, but had no effect on the other tested cell lines. In conclusion, Ihh and its receptors Ptc and Smo are expressed in pancreatic cancer, and blockage of hedgehog signaling results in inhibition of pancreatic cancer cell growth, suggesting that aberrant activation of the Ihh signaling pathway contributes to tumor development in this malignancy.
    International Journal of Cancer 08/2004; 110(5):668-76. · 6.20 Impact Factor
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    ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive human malignancy in which Smad7 is commonly overexpressed. Analysis by differential display identified thioredoxin-1 (TRX) as a gene whose basal expression is increased in COLO-357 pancreatic cancer cells engineered to overexpress Smad7. To delineate the biological consequences of TRX overexpression, we assessed TRX mRNA levels in PDAC and studied the effects of increased TRX levels in Smad7-overexpressing cells. By northern blotting, TRX mRNA levels were increased in PDAC samples by comparison with the normal pancreas. Moreover, analysis of laser-captured pancreatic cancer cells revealed parallel increases in Smad7 and TRX mRNA levels. Retroviral infection of an antisense TRX cDNA suppressed TRX protein levels and blunted the increased capacity of Smad7-overexpressing cells to form colonies in soft agar. 1-Methyl-propyl-2-imidazolozyl disulfide, a TRX inhibitor, markedly suppressed the growth of sham-transfected COLO-357 cells and enhanced the growth inhibitory actions of cis-diamminedichloroplatinum(II) (CDDP). CDDP also induced apoptosis, as evidenced by induction of DNA laddering, PARP cleavage, and caspase-3/9 activities. These pro-apoptotic actions were greatly attenuated in Smad7-overexpressing cells, which exhibited a more prolonged association of TRX with the apoptosis inducer apoptosis signal-regulating kinase-1, and enhanced nuclear factor kappaB activation in response to CDDP. These findings suggest that TRX is downstream of Smad7 in a pathway that confers a growth advantage to pancreatic cancer cells and that increases their resistance to CDDP-mediated apoptosis, implying novel regulatory functions for Smad7.
    Cancer Research 06/2004; 64(10):3599-606. · 8.65 Impact Factor
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    ABSTRACT: Surgical Treatment of Chronic PancreatitisChronic pancreatitis is characterized by recurrent episodes of pancreatitis and a chronic pain syndrome. The pancreatic structure becomes more and more fibrotic, and the patients suffer from exocrine and endocrine pancreatic insufficiency. The pathogenesis of the pain is based on the release of inflammatory cytokines, changes of the sensory nerves, and an increase of the intraductal and parenchymal pressures in the pancreas. The surgical therapy consists of drainage operations and&sol;or pancreatic resections. In the last decade organpreserving operations such as the duodenum-preserving pancreatic head resection has evolved. Prospective studies demonstrated better results for duodenum-preserving pancreatic head resection in terms of quality of life and endocrine function. After modern pancreatic surgery, up to 90&percnt; of the patients are free of pain, and over 70&percnt; sustain a normal quality of life index.
    Chirurgische Gastroenterologie 01/2004; 20:14-20. · 0.14 Impact Factor
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    ABSTRACT: Neurotrophins (NTs) can stimulate cell proliferation and differentiation in various cell types, and play a role in certain human cancers. In this study we analyzed the expression and localization of NTs and their receptors in microdissected pancreatic cancer tissue samples, and studied their ability to stimulate cell growth. The expression of nerve growth factor, brain-derived neurotrophic factor, NT-3, and NT-4/5, and the receptors tropomyosin receptor kinase A, B, and C, and P75 was studied in pancreatic cancer cell lines, and normal and pancreatic ductal adenocarcinoma (PDAC) tissue samples by quantitative reverse transcription-PCR. Laser capture microdissection was performed in 21 PDAC samples, and mRNA levels were determined in cancer cells, acinar cells, desmoplastic stroma areas, and nerve fibers. Cell growth assays with NTs and in coculture with dorsal root ganglia were performed. NT receptors were differentially expressed in the cancer cell lines, whereas tropomyosin receptor kinase C was not detectable. NTs modulated pancreatic cancer cell growth. Analysis of nonmicrodissected samples revealed that all of the receptors and tested ligands were overexpressed in PDAC when compared with normal pancreas. Analysis of laser captured samples revealed that NTs and their receptors were expressed in the cancer cells but were especially abundant in the intratumoral nerves. Coculture of dorsal root ganglia with T3M4 cells significantly enhanced the proliferation of this cell line. The abundance of NTs in the intratumoral nerves in PDAC and the presence of NT receptors in the cancer cells, in conjunction with the ability of NTs to modulate pancreatic cancer cell growth, point to potential paracrine and autocrine effects of NTs in PDAC. Thus, our findings provide additional evidence that blocking NT actions may have a therapeutic potential in PDAC.
    Clinical Cancer Research 12/2003; 9(14):5127-36. · 7.84 Impact Factor
  • K Ketterer, H Friess, M W Büchler
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    ABSTRACT: Molecular research techniques developed in recent years have increased our knowledge of the pathophysiology of pancreatic cancer tremendously. We now know that the malignant phenotype of pancreatic cancer is defined by the expression of growth stimulatory factors, their receptors and gene alterations. To translate molecular knowledge into new clinical therapy will be the challenge of the future. Although we have not yet developed direct clinical applications for our molecular findings, new diagnostic and therapeutic approaches are in development. Gene therapies such as antisense technology, pro-drug activation and the transfer of non-functioning growth factor receptors are potential new therapeutic options for the future. Wider clinical use can be expected in upcoming years.
    Langenbecks Archiv für Chirurgie. Supplement. Kongressband. Deutsche Gesellschaft für Chirurgie. Kongress 02/1998; 115:405-10.
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    ABSTRACT: Background: Neurotrophins (NTs) can stimulate cell proliferation and differentiation in various cell types and have been shown to play a role in certain human cancers. Using northern blot analysis and in situ hybridization, we have previously reported that NGF and its receptor TrkA are overexpressed in pancreatic ductal adenocarcinomas (PDACs). It has also been suggested that the aberrant expression of the NTs or the Trk- receptor family in PDAC is associated with perineural invasion. In this study we per- formed LCM and quantitative RT-PCR analysis for NTs and their receptors in pancreatic cancer cell lines and tissues, and studied the ability of NTs to stimulate cell growth in vitro. Patients and Methods: Quantitative RT-PCR and immunoblotting was performed on six pancreatic cancer cell lines. Three of these cell lines (CAPAN-1, PANC-1 and T3M4) were subjected to MTT-growth assay for BDNF, NT-3 and NT-4. PDACs (n 21) were subjected to LCM. Cell type specific RNA was extracted from cancer cells, acinar cells and nerve fibers and analyzed by real time RT- PCR for NGF, BDNF, NT-3 and NT-4/5 as well as the receptors TrkA, B, C and P75. Results: The receptors TrkA, TrkB and P75 and all 4 tested growth factors were differ- entially expressed in the pancreatic cancer cell lines while TrkC mRNA was below the level of detection. BDNF stimulated cell growth in all examined cell lines while NT-3 and NT-4 had variable effects. Expression of the receptors (TrkA, B, C and P75) and their ligands (NGF, BDNF, NT-3 and NT-4/5) was elevated in the nerve cells, by com- parison with either the cancer cells or acinar cells. BDNF was also expressed at rela- tively high levels in the cancer cells. Conclusion: These data indicate that increased levels of NTs in PDAC are mainly due to increased expression in the nerve cells, and that some cancer cells are growth stimu- lated by certain NTs. Our findings therefore raise the possibility that nerve cells and pan- creatic cancer cells exert autocrine and paracrine effects on each other through the production of NTs, thereby conferring a growth advantage to both cell types. Strategies aimed at abrogating these autocrine/paracrine pathways may therefore have a therapeu- tic potential in this disorder. Pancreatology 2002;2:217-361

Publication Stats

351 Citations
63.98 Total Impact Points

Institutions

  • 2009
    • Technische Universität München
      • Clinic and Polyclinic for Surgery
      München, Bavaria, Germany
  • 2004–2006
    • Universität Heidelberg
      • Institute of Pathology (Mannheim)
      Heidelberg, Baden-Wuerttemberg, Germany
    • Dartmouth–Hitchcock Medical Center
      Lebanon, New Hampshire, United States
  • 2003
    • University of California, Irvine
      • Department of Medicine
      Irvine, CA, United States