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1.  Silencing of MGMT expression by promoter hypermethylation in the metaplasia–dysplasia–carcinoma sequence of Barrett’s esophagus 
Cancer letters  2008;275(1):117-126.
To determine the relevance of MGMT in Barrett’s carcinogenesis, we analyzed promotor hypermethylation and expression of MGMT in Barrett’s adenocarcinomas and its paired precursor lesions from 133 patients using a methylation-specific PCR, real-time RT-PCR and immunohistochemistry. Hypermethylation was detected in 78.9% of esophageal adenocarcinomas, in 100% of Barrett’s intraepithelial neoplasia, in 88.9% of Barrett’s metaplasia, but only in 21.4% of normal esophageal mucosa samples (P < 0.001) and correlated significantly with downregulation of MGMT transcripts (P = 0.048) and protein expression (P = 0.02). Decrease of protein expression was significantly correlated with progressed stage of disease, lymph node invasion and tumor size. We conclude, that aberrant promoter methylation of MGMT is a frequent and early event during tumorigenesis of Barrett’s esophagus. High prevalence of MGMT hypermethylation may represent a candidate marker for improved diagnosis and targeted therapy in Barrett’s adenocarcinoma.
PMCID: PMC4028828  PMID: 19027227
O6-methylguanine-DNA methyltransferase (MGMT); Hypermethylation; Carcinogenesis; Barrett’s metaplasia; Barrett’s adenocarcinoma
2.  Induction of Premalignant Host Responses by Cathepsin X/Z-Deficiency in Helicobacter Pylori-Infected Mice 
PLoS ONE  2013;8(7):e70242.
Helicobacter pylori are responsible for the induction of chronic gastric inflammation progressing to atrophy, metaplasia, and gastric cancer. The overexpression of Cathepsin X/Z (Ctsz) in H. pylori-infected mucosa and gastric cancer is mediated predominantly by an augmented migration of ctsz−/−positive macrophages and the up-regulation of Ctsz in tumor epithelium. To explore the Ctsz-function in the context of chronic inflammation and the development of preneoplastic lesions, we used Ctsz-deficient mice in a H. pylori gastritis model. Ctsz−/− and wild-type (wt) mice were infected with H. pylori strain SS1. The mice were sacrificed at 24, 36, and 50 weeks post infection (wpi). The stomach was removed, and gastric strips were snap-frozen or embedded and stained with H&E. Tissue sections were scored for epithelial lesions and inflammation. Ki-67 and F4/80 immunostaining were used to measure epithelial cell proliferation and macrophage infiltration, respectively. The upregulation of compensating cathepsins and cytokines were confirmed by Western blotting and quantitative RT-PCR. SS1-infected wt and ctsz−/− mice showed strong inflammation, foveolar hyperplasia, atrophy, and cystically-dilated glands. However, at 50 wpi, ctsz−/− mice developed significantly more severe spasmolytic polypeptide-expressing metaplasia (SPEM), showed enhanced epithelial proliferation, and higher levels of infiltrating macrophages. Induction of cytokines was higher and significantly prolonged in ctsz−/− mice compared to wt. Ctsz deficiency supports H. pylori-dependent development of chronic gastritis up to metaplasia, indicating a protective, but not proteolytic, function of Ctsz in inflammatory gastric disease.
PMCID: PMC3728094  PMID: 23936173
3.  Role of tight junction proteins in gastroesophageal reflux disease 
BMC Gastroenterology  2012;12:128.
Gastroesophageal reflux disease (GERD) is associated with impaired epithelial barrier function that is regulated by cell-cell contacts. The aim of the study was to investigate the expression pattern of selected components involved in the formation of tight junctions in relation to GERD.
Eighty-four patients with GERD-related symptoms with endoscopic signs (erosive: n = 47) or without them (non-erosive: n = 37) as well as 26 patients lacking GERD-specific symptoms as controls were included. Endoscopic and histological characterization of esophagitis was performed according to the Los Angeles and adapted Ismeil-Beigi criteria, respectively. Mucosal biopsies from distal esophagus were taken for analysis by histopathology, immunohistochemistry and quantitative reverse-transcription polymerase chain reaction (RT-PCR) of five genes encoding tight junction components [Occludin, Claudin-1, -2, Zona occludens (ZO-1, -2)].
Histopathology confirmed GERD-specific alterations as dilated intercellular spaces in the esophageal mucosa of patients with GERD compared to controls (P < 0.05). Claudin-1 and −2 were 2- to 6-fold upregulation on transcript (P < 0.01) and in part on protein level (P < 0.015) in GERD, while subgroup analysis of revealed this upregulation for ERD only. In both erosive and non-erosive reflux disease, expression levels of Occludin and ZO-1,-2 were not significantly affected. Notably, the induced expression of both claudins did not correlate with histopathological parameters (basal cell hyperplasia, dilated intercellular spaces) in patients with GERD.
Taken together, the missing correlation between the expression of tight junction-related components and histomorphological GERD-specific alterations does not support a major role of the five proteins studied in the pathogenesis of GERD.
PMCID: PMC3503771  PMID: 22994974
Gastroesophageal reflux disease; Tight junction; Claudins; Esophagitis; Inflammation
4.  Successful interdisciplinary treatment of renal cell carcinoma with tumour thrombus into inferior vena cava using multimodal protocol and organ-extending R0 resection in rare horseshoe kidney and doubled right organ 
BMJ Case Reports  2010;2010:bcr04.2009.1802.
This is the first case ever reported showing a combination of renal cell carcinoma (RCC) with tumour thrombus into inferior vena cava (IVC), horseshoe kidney and doubled right kidney that was successfully treated. Even in advanced tumour lesions of the kidney, curative treatment is a feasible and safe option by using interdisciplinary cooperation and expertise. However, this requires an adequate diagnostic work-up to clarify resectability and optimal perioperative and postoperative care, and also advanced surgical skills exhausting all potential options for complete tumour resection in a centre of excellence. Achieving R0 resection with a reasonable risk-benefit ratio for the patient, which should be the primary aim, can distinctly improve survival chances as published cases in literature have indicated. RCC-derived IVC tumour thrombus as an extra-renal tumour manifestation by continuous intravascular tumour growth (also classified as secondary IVC tumour lesion) can be considered no serious contraindication to aim for curative surgery.
PMCID: PMC3047170  PMID: 22751093
5.  Serological assessment of gastric mucosal atrophy in gastric cancer 
BMC Gastroenterology  2012;12:10.
Non-invasive tools for gastric cancer screening and diagnosis are lacking. Serological testing with the detection of pepsinogen 1 (PG1), pepsinogen 2 (PG2) and gastrin 17 (G17) offers the possibility to detect preneoplastic gastric mucosal conditions. Aim of this study was to assess the performance of these serological tests in the presence of gastric neoplasia.
Histological and serological samples of 118 patients with gastric cancer have been assessed for tumor specific characteristics (Laurén type, localisation), degree of mucosal abnormalities (intestinal metaplasia, atrophy) and serological parameters (PG1, PG2, PG1/2-ratio, G17, H. pylori IgG, CagA status). Association of the general factors to the different serological values have been statistically analyzed.
Patients with intestinal type gastric cancer had lower PG1 levels and a lower PG1/2-ratio compared to those with diffuse type cancer (p = 0.003). The serum levels of PG2 itself and G17 were not significantly altered. H. pylori infection in general had no influence on the levels of PG1, PG2 and G17 in the serum of gastric cancer patients. There was a trend towards lower PG1 levels in case of positive CagA-status (p = 0.058). The degree of both intestinal metaplasia and atrophy correlated inversely with serum levels for PG1 and the PG1/2-ratio (p < 0.01). Laurén-specific analysis revealed that this is only true for intestinal type tumors. Univariate ANOVA revealed atrophy and CagA-status as the only independent factors for low PG1 and a low PG1/2-ratio.
Glandular atrophy and a positive CagA status are determinant factors for decreased pepsinogen 1 levels in the serum of patients with gastric cancer. The serological assessment of gastric atrophy by analysis of serum pepsinogen is only adequate for patients with intestinal type cancer.
PMCID: PMC3280182  PMID: 22289789
Gastric cancer; Helicobacter pylori; intestinal metaplasia; glandular atrophy; gastrin; pepsinogen; cardia cancer
6.  Kidney Pathology Precedes and Predicts the Pathological Cascade of Cerebrovascular Lesions in Stroke Prone Rats 
PLoS ONE  2011;6(10):e26287.
Human cerebral small vessel disease (CSVD) has been hypothesized to be an age-dependent disease accompanied by similar vascular changes in other organs. SHRSP feature numerous vascular risk factors and may be a valid model of some aspects of human CSVD. Here we compare renal histopathological changes with the brain pathology of spontaneously hypertensive stroke-prone rats (SHRSP).
Material and Methods
We histologically investigated the brains and kidneys of 61 SHRSP at different stages of age (12 to 44 weeks). The brain pathology (aggregated erythrocytes in capillaries and arterioles, microbleeds, microthromboses) and the kidney pathology (aggregated erythrocytes within peritubular capillaries, tubular protein cylinders, glomerulosclerosis) were quantified separately. The prediction of the brain pathology by the kidney pathology was assessed by creating ROC-curves integrating the degree of kidney pathology and age of SHRSP.
Both, brain and kidney pathology, show an age-dependency and proceed in definite stages whereas an aggregation of erythrocytes in capillaries and arterioles, we parsimoniously interpreted as stases, represent the initial finding in both organs. Thus, early renal tubulointerstitial damage characterized by rather few intravasal erythrocyte aggregations and tubular protein cylinders predicts the initial step of SHRSPs' cerebral vascular pathology marked by accumulated erythrocytes. The combined increase of intravasal erythrocyte aggregations and protein cylinders accompanied by glomerulosclerosis and thrombotic renal microangiopathy in kidneys of older SHRSP predicts the final stages of SHRSPs' cerebrovascular lesions marked by microbleeds and thrombotic infarcts.
Our results illustrate a close association between structural brain and kidney pathology and support the concept of small vessel disease to be an age-dependent systemic pathology. Further, an improved joined nephrologic and neurologic diagnostic may help to identify patients with CSVD at an early stage.
PMCID: PMC3198774  PMID: 22031827
7.  Upregulation of Leukotriene Receptors in Gastric Cancer 
Cancers  2011;3(3):3156-3168.
Leukotrienes (LT) mediate allergic and inflammatory processes. Previously, we identified significant changes in the expression pattern of LT receptors in the gastric mucosa after eradication of Helicobacter pylori infection. The aim of the present study was to evaluate the expression of 5-lipoxygenase (5-LOX) and LT receptors in gastric cancer (GC).
The expression of 5-LOX and receptors for LTB4 (BLT-1, BLT-2) and cysteinyl-LT (CysLT-1, CysLT-2) were analyzed by immunohistochemistry (IHC) in GC samples of 35 consecutive patients who underwent gastrectomy and in 29 tumor-free tissue specimens from gastric mucosa.
Male-to-female ratio was 24:11. The median age was 70 years (range 34–91). Twenty-two patients had GC of intestinal, six of diffuse, six of mixed and one of undifferentiated type. The IHC analysis showed a nearly ubiquitous expression of studied proteins in GC (88–97%) and in tumor-free specimens as well (89–100%). An increase in the immunoreactive score of both BLT receptors and CysLT-1 was observed in GC compared to tumor-free gastric mucosa (p < 0.001 for BLT-1; p < 0.01 for BLT-2 and CysLT-1, Mann-Whitney U-test). No differences in the IHC expression of 5-LOX and CsyLT-2 were observed between GC and tumor-free mucosa. The expression of BLT-2, CysLT-1 and CysLT-2 was increased in GC of intestinal type when compared to the diffuse type (p < 0.05; Mann-Whitney U-test).
LTB4 receptors and CysLT-1 are up-regulated in GC tissue implying a role in gastric carcinogenesis.
PMCID: PMC3759191  PMID: 24212950
leukotriene receptors; gastric cancer; cysteinyl-leukotrienes
8.  Mucosal Progranulin expression is induced by H. pylori, but independent of Secretory Leukocyte Protease Inhibitor (SLPI) expression 
BMC Gastroenterology  2011;11:63.
Mucosal levels of Secretory Leukocyte Protease Inhibitor (SLPI) are specifically reduced in relation to H. pylori-induced gastritis. Progranulin is an epithelial growth factor that is proteolytically degraded into fragments by elastase (the main target of SLPI). Considering the role of SLPI for regulating the activity of elastase, we studied whether the H. pylori-induced reduction of SLPI and the resulting increase of elastase-derived activity would reduce the Progranulin protein levels both ex vivo and in vitro.
The expression of Progranulin was studied in biopsies of H. pylori-positive, -negative and -eradicated subjects as well as in the gastric tumor cell line AGS by ELISA, immunohistochemistry and real-time RT-PCR.
H. pylori-infected subjects had about 2-fold increased antral Progranulin expression compared to H. pylori-negative and -eradicated subjects (P < 0.05). Overall, no correlations between mucosal Progranulin and SLPI levels were identified. Immunohistochemical analysis confirmed the upregulation of Progranulin in relation to H. pylori infection; both epithelial and infiltrating immune cells contributed to the higher Progranulin expression levels. The H. pylori-induced upregulation of Progranulin was verified in AGS cells infected by H. pylori. The down-regulation of endogenous SLPI expression in AGS cells by siRNA methodology did not affect the Progranulin expression independent of the infection by H. pylori.
Taken together, Progranulin was identified as novel molecule that is upregulated in context to H. pylori infection. In contrast to other diseases, SLPI seems not to have a regulatory role for Progranulin in H. pylori-mediated gastritis.
PMCID: PMC3115905  PMID: 21612671
9.  Inflammatory Myofibroblastic Tumor of the Pancreatic Head: An Unusual Cause of Recurrent Acute Pancreatitis – Case Presentation of a Palliative Approach after Failed Resection and Review of the Literature 
Case Reports in Gastroenterology  2010;4(3):443-451.
Inflammatory myofibroblastic tumors (IMTs) are a rare cause of echo-poor pancreatic head enlargement. Histologically, IMTs are characterized by spindle-shaped myofibroblasts or fibroblasts accompanied by a mixed immune cell infiltration. The most common localizations of IMTs have been reported in lung, mesentery and omentum, especially in children and young adults. IMTs show infiltrating growth, multilocular appearance and also metastasis have been reported. Curative resection is the only therapeutic option so far. In the palliative situation, evident data and clear guidelines for this rare tumor entity are missing. We report on a 44-year-old male with an unresectable IMT of the pancreatic head causing recurrent episodes of acute pancreatitis that resulted in a chronic obstructive course of the disease. The patient entered a palliative therapeutic regimen including radiation therapy and antiinflammatory medication. In a regular follow-up of 12 months, he presented with stable disease after initial progression. This case of local progressive IMT of the pancreatic head was managed with a palliative therapeutic regimen and is discussed based on the current literature.
PMCID: PMC2988857  PMID: 21113286
Inflammatory myofibroblastic tumor; Pancreas; Recurrent acute pancreatitis; Chronic obstructive pancreatitis
10.  Early Involvement of Death-Associated Protein Kinase Promoter Hypermethylation in the Carcinogenesis of Barrett's Esophageal Adenocarcinoma and Its Association with Clinical Progression1 
Neoplasia (New York, N.Y.)  2007;9(3):236-245.
Esophageal Barrett's adenocarcinoma (BA) develops through a multistage process, which is associated with the transcriptional silencing of tumor-suppressor genes by promoter CpG island hypermethylation. In this study, we explored the promoter hypermethylation and protein expression of proapoptotic deathassociated protein kinase (DAPK) during the multistep Barrett's carcinogenesis cascade. Early BA and paired samples of premalignant lesions of 61 patients were analyzed by methylation-specific polymerase chain reaction and immunohistochemistry. For the association of clinicopathological markers and protein expression, an immunohistochemical tissue microarray analysis of 66 additional BAs of advanced tumor stages was performed. Hypermethylation of DAPK promoter was detected in 20% of normal mucosa, 50% of Barrett's metaplasia, 53% of dysplasia, and 60% of adenocarcinomas, and resulted in a marked decrease in DAPK protein expression (P < .01). The loss of DAPK protein was significantly associated with advanced depth of tumor invasion and advanced tumor stages (P < .001). Moreover, the severity of reflux esophagitis correlated significantly with the hypermethylation rate of the DAPK promoter (P < .003). Thus, we consider DAPK inactivation by promoter hypermethylation as an early event in Barrett's carcinogenesis and suggest that a decreased protein expression of DAPK likely plays a role in the development and progression of BA.
PMCID: PMC1838580  PMID: 17401463
Barrett's adenocarcinoma; Barrett's metaplasia; DAPK; reflux esophagitis; inflammation
11.  Hypermethylation and Loss of Expression of Glutathione Peroxidase-3 in Barrett's Tumorigenesis1 
Neoplasia (New York, N.Y.)  2005;7(9):854-861.
Chronic gastroesophageal reflux disease is a known risk factor for Barrett's esophagus (BE), that induces oxidative mucosal damage. Glutathione peroxidase-3 (GPx3) is a secretory protein with potent extracellular antioxidant activity. Herein, we have investigated the mRNA and protein expression of GPx3, and explored promoter hypermethylation as an epigenetic mechanism for GPx3 gene inactivation during Barrett's carcinogenesis. Quantitative real-time reverse transcription polymerase chain reaction on 42 Barrett's adenocarcinomas (BAs) revealed consistently reduced levels of GPx3 mRNA in 91% of tumor samples. GPx3 promoter hypermethylation was detected in 62% of Barrett's metaplasia, 82% of dysplasia, and 88% of BA samples. Hypermethylation of both alleles of GPx3 was most frequently seen in BA (P = .001). Immunohistochemical staining of GPx3 in matching tissue sections (normal, BE, Barrett's dysplasia, and BA) revealed a weak-to-absent GPx3 staining in Barrett's dysplasia and adenocarcinoma samples where the promoter was hypermethylated. The degree of loss of immuno-histochemistry correlated with the hypermethylation pattern (monoallelic versus biallelic). The observed high frequency of promoter hypermethylation and progressive loss of GPx3 expression in BA and its associated lesions, together with its known function as a potent antioxidant, suggest that epigenetic inactivation and regulation of glutathione pathway may be critical in the development and progression of BE.
PMCID: PMC1501938  PMID: 16229808
Barrett's; dysplasia; cancer; GPx3; ROS

Results 1-11 (11)