Activation of peroxisome proliferators-activated receptor Γ (PPARΓ) inhibits the growth of human...
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A646 AGA ABSTRACTS 3283 IS THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) OVEREXPRESSED IN GASTRINOMAS? Paolo L. Peghini, Stephan U. Goebel, Fathia Gibril, Mark Raffeld, Robert T. Jensen, Jose Serrano, National Inst of Health, Bethesda, MD. The EGFR is overexpressed in many tumors including pancreatic exocrine cancers. Whether it is overexpressed in pancreatic endocrine tumors (PETs) such as gastrinomas is unclear. In one report all gastrinomas expressed EGFR, whereas with other PETs EGFR was only rarely ex- pressed. Because overexpression of EGFR is associated with poor prog- nosis in many tumors, and a proportion of gastrinomas are aggressive, the expression of EGFR may have prognostic significance. To address this question the following study was performed. Gastrinomas from 16 patients with Zollinger-Ellison syndrome were examined for EGFR expression and the expression was compared to the tumor growth. Competitive RT-PCR and immunohistochemistry were performed on 10 gastrinomas each. Par- affin-embedded sections were stained using 3 different monoclonal anti- bodies. Breast cancer specimens served as positive controls. mRNA levels were assessed by competitive RT-PCR with mRNA-specific primers. EGFR mRNA levels were normalized for b-actin mRNA levels and ex- pressed as the ratio between the two. Pooled mRNA fractions from normal human pancreatic tissue were used as normal controls. Sixteen gastrinomas (6M, 10F), 14 sporadic tumors and 2 MEN-l associated gastrinomas were analyzed. The mean age of the patients was 43.6±0.4 yr [15.5-65.3). The mean fasting serum gastrin level was 5934±2018 pglml [404-26667]. The mean follow-up was 5.3±0.7 yr [0.9-11.2). Five patients had aggressive disease. All tumors expressed EGFR mRNA. The mean EGFRIb-actin ratio of the gastrinomas was lower than that of normal pancreatic tissue (0.0085±0.OO24 vs. 0.055±0.025). In none of the 10 gastrinomas did the ratio exceed that found in normal pancreas. The mean EGFRIb-actin ratio did not differ between aggressive (n=5) and benign (n=5) gastrinomas (0.040±0.035 vs. 0.0115±0.004). The EGFRIb-actin ratio did not differ between duodenal gastrinomas (n=5) and primary tumors in another location (n=4), (0.011±0.004 vs. 0.OO6±0.OO2). Immunostaining for EGFR was negative in each of the 10 tumors tested. The results show that the EGFR is expressed in all gastrinomas, however it is not overexpressed compared to normal pancreatic tissue. Furthermore its level of expression does not correlate with the aggressiveness of the tumor or with the primary location of the tumor, which has been shown to be an important determi- nant of metastatic potential. These results suggest that in contrast to exocrine pancreatic tumors, in PETs overexpression of EGFR is unlikely to be an important pathogenic process. 3284 POWER·DOPPLER SONOGRAPHY AND 2ND HARMONIC 1M· AGING IN THE DIFFERENTIAL DIAGNOSIS OF PANCREATIC TUMOURS USING THE ECHO ENHANCER LEVOVIST®. Steffen Rickes, Holger Neye, Renate Heyne, Kenneth Ocran, Kathrin Reim, Herbert Lochs, Wolfram Wermke, Univ Hosp Charite, Dept of Internal Medicine IV, Berlin, Germany. Objective: Differentiation of pancreatic tumours by conventional ultra- sound is difficult. Therefore we investigated the value of an echo enhancer in the differential diagnosis of pancreatic tumours. Patients and methods: 42 patients with suspected pancreatic tumours at the conventional ultra- sound were investigated by power-Doppler sonography and 2nd harmonic imaging using the echo enhancer Levovist® (300mglml, bolus i.v., Scher- ing AG, Berlin, Germany). Signal behaviour and vascularisation pattern of the pancreatic tumours compared to the surrounding tissue were used for the ultrasound characterization. Histological diagnoses were obtained after surgical tumour resection or by percutaneous needle biopsy. Results: See table. Conclusion: Echo enhanced power-Doppler sonography and 2nd harmonic imaging have a high accuracy in the differential diagnoses of neuroendocrine tumours and adenocarcinomas of the pancreas. Suspected diagnoses by echo enhanced sonography. suspected diagnoses true false histology of false diagnoses adenocarcinoma 20 2 2 pancreatitis neuroendocrine tumour 12 0 cystadenoma 2 3 2 adena- ard1cystadenocarcinoma cystadenocarcinoma 1 1 1cystadenoma lymphoma 1 0 total 36 6 GASTROENTEROLOGY Vol. 118, No.4 3285 PRESENTING CLINICAL FEATURES IN ZOLLINGER·ELLISON SYNDROME (ZES): RESULTS FROM A PROSPECTIVE STUDY OF 261 CASES. Praveen K. Roy, Alaa Abou-Saif, Homayoun Shojamanesh, Fathia Gibril, Robert T. Jensen, National Inst of Health, Bethesda, MD. The presenting features of ZES are poorly documented with available data from small series or collected case reports. Also, it is unknown if recent use of gastric antisecretory drugs or increased awareness of ZES is affecting its presentation or diagnosis. To evaluate these points we prospectively ana- lyzed the results in 261 patients ZES. On initial evaluation, all patients were questioned about symptoms possibly due to ZES, history of endocri- nopathies and prior surgeries. All patients had fasting serum gastrin levels, UGI endoscopy and tumor imaging studies. During endoscopy particular attention was paid to the presence of prominent gastric body folds and esophageal or pyloric strictures. Multiple endocrine neoplasia type 1 (MEN-I) was sought by history and laboratory evaluations. MEN-l was present in 22%. Mean age at onset was 41.1 ±0.7 yrs, with MEN-l patients presenting at a younger age (p<O.OOOI). 3% had onset of the disease < age 20 yrs and 7% > 60 yrs. A delay occurred of 5.2±0.4 yrs in making the diagnosis in all patients. A shorter duration of symptoms was noted in females, patients with liver metastasis, and patients with primary tumor size > 3 ern, Symptoms frequency was abdominal pain = diarrhea > both > heartburn > nausea> vomiting = bleeding, pain and bleeding > weight loss. Prominent gastric body folds were noted in 94%, esophageal stricture in 4% and duodenal or pyloric scarring in 10%. Comparison of presentation pre-H2-blockers « 1980, n= 36), post H2-blockers (1981-89, n=118) and post PPIs (>1990, n=107) demonstrate no change in age of onset; delay in diagnosis; frequency of pain, diarrhea, weight loss; fre- quency of complications of severe peptic disease (bleeding, perforations, esophageal strictures, pyloric scarring). Since H2-blocker introduction, fewer patients had gastric acid-reducing surgery. The location of the primary tumor did not affect the clinical presentation. These results dem- onstrate that abdominal pain, diarrhea and heartburn are still the most common presenting symptoms in ZES and that diarrhea is more common than previously reported. Patients with MEN-I with ZES present at earlier age, however in general the initial symptoms were similar to patients without MEN-I. Overall, neither the introduction of successful antisecre- tory therapy nor widespread publications about ZES attempting to increase its awareness have changed the clinical presentation, shortened the delay in diagnosis or reduced the incidence of patients presenting with peptic complications. 3286 ACTIVATION OF PEROXISOME PROLIFERATOR·ACTIVATED RECEPTOR r (pPARr) INHIBITS THE GROWTH OF HUMAN PANCREATIC CANCER. Tamito Sasaki, Akira Tsuchida, Yoshifumi Fujimoto, Kenji Matsubara, Shigeru Yamamoto, Yousuke Kawasaki, Kenji Morinaka, Hiroki Inoue, Yukio Kuwada, Masateru Murakami, Souichirou Yamasaki, Goro Ka- jiyama, Hiroshima Univ Sch of Med, Hiroshima, Japan. Background Peroxisome proliferator-activated receptor gamma (PPARy) is a nuclear receptor superfamily and regulates adipocyte differentiation. Recently, it has been reported that PPAR'Y is expressed in cancer cells and activation of PPAR'Y leads to terminal differentiation and growth suppres- sion. In the present study, we examined the expression of PPARy in human pancreatic cancer and evaluated the possible effects of ligand-induced activation of PPARy on pancreatic cancer cell growth. Materials and methods We used three human pancreatic cancer cell lines (PANC-l, MIA PaCa-2 and Capan-2), surgically resected pancreatic cancer tissues and adjacent normal pancreatic tissues as objects of study. To examine the expression of PPARy, reverse transcription-polymerase chain reaction, western blotting and immunoprecipitation were performed. To evaluate the binding ability of PPARy to its responsive element, gel sift assay was performed using nuclear protein from cells and oligonucleotide synthesized according to the sequence of rat acyl-CoA oxidase. To clarify the biolog- ical effects of PPARy on cell growth, cells were treated with serial concentration of ligands of PPARy (troglitazone and rosiglitazone) or metabolic analog of troglitazone, which fail to bind to PPARy, for indi- cated time, and then growth assay were performed using Cell Counting Kit™ and colony assay. Results PPARy-mRNA was detected in all inves- tigated cells and in 5 out of 7 (71%) cases of pancreatic cancer tissues. In contrast, no amplified signal was observed in adjacent pancreatic tissues. PPARy-protein was also detected in three cell lines. Gel shift analysis revealed the proteins in nuclear extracts of PANC-I have a specific binding to PPAR responsive element. Interestingly, the cell growth was signifi- cantly inhibited by treatment with troglitazone and rosiglitazone in a dose and in a time dependent manner (P<O.OI). The effective dose that inhibited 50 % growth (ED so) oftroglitazone on PANC-l, MIA PaCa-2 and Capan-2 was 9.5 JLM, 22.4 JLM and 14.3 JLM, respectively. ED so of rosiglitazone on PANC-l, MIA PaCa-2 and Capan-2 was 11.2 JLM, 25.8 JLM and 18.2 JLM, respectively. In contrast, metabolic analog of troglitazone cannot affect to cell growth Conclusion These observations suggested that PPAR'Y acts important role in human pancreatic cancer growth and ligand-induced activation of PPARy may be a useful therapeutic strategy against pancre- atic cancer.
Transcript of Activation of peroxisome proliferators-activated receptor Γ (PPARΓ) inhibits the growth of human...
A646 AGA ABSTRACTS
3283
IS THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR)OVEREXPRESSED IN GASTRINOMAS?Paolo L. Peghini, Stephan U. Goebel, Fathia Gibril, Mark Raffeld, RobertT. Jensen, Jose Serrano, National Inst of Health, Bethesda, MD.
The EGFR is overexpressed in many tumors including pancreatic exocrinecancers. Whether it is overexpressed in pancreatic endocrine tumors(PETs) such as gastrinomas is unclear. In one report all gastrinomasexpressed EGFR, whereas with other PETs EGFR was only rarely expressed. Because overexpression of EGFR is associated with poor prognosis in many tumors, and a proportion of gastrinomas are aggressive, theexpression of EGFR may have prognostic significance. To address thisquestion the following study was performed. Gastrinomas from 16 patientswith Zollinger-Ellison syndrome were examined for EGFR expression andthe expression was compared to the tumor growth. Competitive RT-PCRand immunohistochemistry were performed on 10 gastrinomas each. Paraffin-embedded sections were stained using 3 different monoclonal antibodies. Breast cancer specimens served as positive controls. mRNA levelswere assessed by competitive RT-PCR with mRNA-specific primers.EGFR mRNA levels were normalized for b-actin mRNA levels and expressed as the ratio between the two. Pooled mRNA fractions from normalhuman pancreatic tissue were used as normal controls. Sixteen gastrinomas(6M, 10F), 14 sporadic tumors and 2 MEN-l associated gastrinomas wereanalyzed. The mean age of the patients was 43.6±0.4 yr [15.5-65.3). Themean fasting serum gastrin level was 5934±2018 pglml [404-26667]. Themean follow-up was 5.3±0.7 yr [0.9-11.2). Five patients had aggressivedisease. All tumors expressed EGFR mRNA. The mean EGFRIb-actin ratioof the gastrinomas was lower than that of normal pancreatic tissue(0.0085±0.OO24 vs. 0.055±0.025). In none of the 10 gastrinomas did theratio exceed that found in normal pancreas. The mean EGFRIb-actin ratiodid not differ between aggressive (n=5) and benign (n=5) gastrinomas(0.040±0.035 vs. 0.0115±0.004). The EGFRIb-actin ratio did not differbetween duodenal gastrinomas (n=5) and primary tumors in anotherlocation (n=4), (0.011±0.004 vs. 0.OO6±0.OO2). Immunostaining forEGFR was negative in each of the 10 tumors tested. The results show thatthe EGFR is expressed in all gastrinomas, however it is not overexpressedcompared to normal pancreatic tissue. Furthermore its level of expressiondoes not correlate with the aggressiveness of the tumor or with the primarylocation of the tumor, which has been shown to be an important determinant of metastatic potential. These results suggest that in contrast toexocrine pancreatic tumors, in PETs overexpression of EGFR is unlikely tobe an important pathogenic process.
3284
POWER·DOPPLER SONOGRAPHY AND 2ND HARMONIC 1M·AGING IN THE DIFFERENTIAL DIAGNOSIS OF PANCREATICTUMOURS USING THE ECHO ENHANCER LEVOVIST®.Steffen Rickes, Holger Neye, Renate Heyne, Kenneth Ocran, KathrinReim, Herbert Lochs, Wolfram Wermke, Univ Hosp Charite, Dept ofInternal Medicine IV, Berlin, Germany.
Objective: Differentiation of pancreatic tumours by conventional ultrasound is difficult. Therefore we investigated the value of an echo enhancerin the differential diagnosis of pancreatic tumours. Patients and methods:42 patients with suspected pancreatic tumours at the conventional ultrasound were investigated by power-Doppler sonography and 2nd harmonicimaging using the echo enhancer Levovist® (300mglml, bolus i.v., Schering AG, Berlin, Germany). Signal behaviour and vascularisation pattern ofthe pancreatic tumours compared to the surrounding tissue were used forthe ultrasound characterization. Histological diagnoses were obtained aftersurgical tumour resection or by percutaneous needle biopsy. Results: Seetable. Conclusion: Echo enhanced power-Doppler sonography and 2ndharmonic imaging have a high accuracy in the differential diagnoses ofneuroendocrine tumours and adenocarcinomas of the pancreas.
Suspected diagnoses byecho enhanced sonography.
suspected diagnoses true false histology of false diagnoses
adenocarcinoma 20 2 2pancreatitisneuroendocrine tumour 12 0cystadenoma 2 3 2adena- ard1cystadenocarcinomacystadenocarcinoma 1 1 1cystadenomalymphoma 1 0total 36 6
GASTROENTEROLOGY Vol. 118, No.4
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PRESENTING CLINICAL FEATURES IN ZOLLINGER·ELLISONSYNDROME (ZES): RESULTS FROM A PROSPECTIVE STUDYOF 261 CASES.Praveen K. Roy, Alaa Abou-Saif, Homayoun Shojamanesh, Fathia Gibril,Robert T. Jensen, National Inst of Health, Bethesda, MD.
The presenting features of ZES are poorly documented with available datafrom small series or collected case reports. Also, it is unknown if recent useof gastric antisecretory drugs or increased awareness of ZES is affecting itspresentation or diagnosis. To evaluate these points we prospectively analyzed the results in 261 patients ZES. On initial evaluation, all patientswere questioned about symptoms possibly due to ZES, history of endocrinopathies and prior surgeries. All patients had fasting serum gastrin levels,UGI endoscopy and tumor imaging studies. During endoscopy particularattention was paid to the presence of prominent gastric body folds andesophageal or pyloric strictures. Multiple endocrine neoplasia type 1(MEN-I) was sought by history and laboratory evaluations. MEN-l waspresent in 22%. Mean age at onset was 41.1 ±0.7 yrs, with MEN-l patientspresenting at a younger age (p<O.OOOI). 3% had onset of the disease < age20 yrs and 7% > 60 yrs. A delay occurred of 5.2±0.4 yrs in making thediagnosis in all patients. A shorter duration of symptoms was noted infemales, patients with liver metastasis, and patients with primary tumorsize > 3 ern, Symptoms frequency was abdominal pain = diarrhea >both > heartburn > nausea> vomiting = bleeding, pain and bleeding >weight loss. Prominent gastric body folds were noted in 94%, esophagealstricture in 4% and duodenal or pyloric scarring in 10%. Comparison ofpresentation pre-H2-blockers « 1980, n= 36), post H2-blockers (1981-89,n=118) and post PPIs (>1990, n=107) demonstrate no change in age ofonset; delay in diagnosis; frequency of pain, diarrhea, weight loss; frequency of complications of severe peptic disease (bleeding, perforations,esophageal strictures, pyloric scarring). Since H2-blocker introduction,fewer patients had gastric acid-reducing surgery. The location of theprimary tumor did not affect the clinical presentation. These results demonstrate that abdominal pain, diarrhea and heartburn are still the mostcommon presenting symptoms in ZES and that diarrhea is more commonthan previously reported. Patients with MEN-I with ZES present at earlierage, however in general the initial symptoms were similar to patientswithout MEN-I. Overall, neither the introduction of successful antisecretory therapy nor widespread publications about ZES attempting to increaseits awareness have changed the clinical presentation, shortened the delay indiagnosis or reduced the incidence of patients presenting with pepticcomplications.
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ACTIVATION OF PEROXISOME PROLIFERATOR·ACTIVATEDRECEPTOR r (pPARr) INHIBITS THE GROWTH OF HUMANPANCREATIC CANCER.Tamito Sasaki, Akira Tsuchida, Yoshifumi Fujimoto, Kenji Matsubara,Shigeru Yamamoto, Yousuke Kawasaki, Kenji Morinaka, Hiroki Inoue,Yukio Kuwada, Masateru Murakami, Souichirou Yamasaki, Goro Kajiyama, Hiroshima Univ Sch of Med, Hiroshima, Japan.
Background Peroxisome proliferator-activated receptor gamma (PPARy)is a nuclear receptor superfamily and regulates adipocyte differentiation.Recently, it has been reported that PPAR'Y is expressed in cancer cells andactivation of PPAR'Y leads to terminal differentiation and growth suppression. In the present study, we examined the expression of PPARy in humanpancreatic cancer and evaluated the possible effects of ligand-inducedactivation of PPARy on pancreatic cancer cell growth. Materials andmethods We used three human pancreatic cancer cell lines (PANC-l, MIAPaCa-2 and Capan-2), surgically resected pancreatic cancer tissues andadjacent normal pancreatic tissues as objects of study. To examine theexpression of PPARy, reverse transcription-polymerase chain reaction,western blotting and immunoprecipitation were performed. To evaluate thebinding ability of PPARy to its responsive element, gel sift assay wasperformed using nuclear protein from cells and oligonucleotide synthesizedaccording to the sequence of rat acyl-CoA oxidase. To clarify the biological effects of PPARy on cell growth, cells were treated with serialconcentration of ligands of PPARy (troglitazone and rosiglitazone) ormetabolic analog of troglitazone, which fail to bind to PPARy, for indicated time, and then growth assay were performed using Cell CountingKit™ and colony assay. Results PPARy-mRNA was detected in all investigated cells and in 5 out of 7 (71%) cases of pancreatic cancer tissues. Incontrast, no amplified signal was observed in adjacent pancreatic tissues.PPARy-protein was also detected in three cell lines. Gel shift analysisrevealed the proteins in nuclear extracts of PANC-I have a specific bindingto PPAR responsive element. Interestingly, the cell growth was significantly inhibited by treatment with troglitazone and rosiglitazone in a doseand in a time dependent manner (P<O.OI). The effective dose that inhibited50 % growth (EDso)oftroglitazone on PANC-l, MIA PaCa-2 and Capan-2was 9.5 JLM, 22.4 JLM and 14.3 JLM, respectively. EDso of rosiglitazone onPANC-l, MIA PaCa-2 and Capan-2 was 11.2 JLM, 25.8 JLM and 18.2 JLM,respectively. In contrast, metabolic analog of troglitazone cannot affect tocell growth Conclusion These observations suggested that PPAR'Y actsimportant role in human pancreatic cancer growth and ligand-inducedactivation of PPARy may be a useful therapeutic strategy against pancreatic cancer.
