Quantitation of Helicobacter pylori in dental plaque samples by competitive polymerase chain reaction

AIM

To establish a competitive PCR (cPCR) assay for quantitation of H pylori organisms in dental plaque samples.

METHODS

The cPCR co-amplified target H pylori DNA and a known amount of internal standard template in the same tube with the same primers directed to 0.86 kb DNA of H pylori. The internal standard was a synthesised DNA bearing the same primer recognition sites at two ends and a non-homologous core sequence as the target DNA fragment. Quantitation was based on determination of the relative, not absolute, amounts of the differently sized and [32P]-dCTP labelled products derived from H pylori DNA and the competitive internal standard after gel electrophoresis separation.

RESULTS

A significant correlation between known amounts of H pylori added to dental plaque samples and the results of the cPCR was found, and a standard line was developed which allowed quantitation of H pylori in the plaque samples. cPCR was performed on supragingival plaque samples from 10 adult patients with H pylori infection in the stomach, and from five adults and six children without H pylori infection in the stomach. The ranges of H pylori numbers were 1-213 (median 25), 6-76 (10), and 4-94 (14) cells/mg of dental plaque in the three groups, respectively.

CONCLUSIONS

cPCR is useful for quantitation of H pylori in supragingival dental plaque samples; however, the number of the organisms in dental plaque samples seems very low.

Role of MT-MMPs and MMP-2 in pancreatic cancer progression

Activation of matrix metalloproteinase-2 (MMP-2) by the membrane-type matrix metalloproteinases (MT-MMPs) has been associated with tumor progression. In the present study, we examined the role of MMP-2 and its activators MT1-MMP, MT2-MMP and MT3-MMP in pancreatic tumor cell invasion and the development of the desmoplastic reaction characteristic of pancreatic cancer tissues. Northern blot analyses revealed that transcript levels of MT1-MMP and MT2-MMP, but not MT3-MMP, were enhanced in pancreatic cancer tissues (n = 18) compared with both chronic pancreatitis (n = 9) and healthy pancreas (n = 9). A good correlation was found between MT1-MMP and both MMP-2 expression (p < 0.01) and activity in pancreatic cancer tissues. In addition, expression and activation of MMP-2 were strongly associated with the extent of the desmoplastic reaction in pancreatic cancer tissues. Invasion assays showed a good correlation between MMP-2 expression and activity and the invasive potential of pancreatic cancer cell lines. In cell lines with high levels of MMP-2 expression and activity, the MMP inhibitor Batimastat led to significant reduction of the number of invading cells. Our results suggest that MT1-MMP is involved in the progression of pancreatic cancer via activation of MMP-2. MMP-2 itself plays an important role in tumor cell invasion and appears to be associated with the development of the characteristic desmoplastic reaction in pancreatic cancer.

Role of MT-MMPs and MMP-2 in pancreatic cancer progression

Activation of matrix metalloproteinase-2 (MMP-2) by the membrane-type matrix metalloproteinases (MT-MMPs) has been associated with tumor progression. In the present study, we examined the role of MMP-2 and its activators MT1-MMP, MT2-MMP and MT3-MMP in pancreatic tumor cell invasion and the development of the desmoplastic reaction characteristic of pancreatic cancer tissues. Northern blot analyses revealed that transcript levels of MT1-MMP and MT2-MMP, but not MT3-MMP, were enhanced in pancreatic cancer tissues (n = 18) compared with both chronic pancreatitis (n = 9) and healthy pancreas (n = 9). A good correlation was found between MT1-MMP and both MMP-2 expression (p < 0.01) and activity in pancreatic cancer tissues. In addition, expression and activation of MMP-2 were strongly associated with the extent of the desmoplastic reaction in pancreatic cancer tissues. Invasion assays showed a good correlation between MMP-2 expression and activity and the invasive potential of pancreatic cancer cell lines. In cell lines with high levels of MMP-2 expression and activity, the MMP inhibitor Batimastat led to significant reduction of the number of invading cells. Our results suggest that MT1-MMP is involved in the progression of pancreatic cancer via activation of MMP-2. MMP-2 itself plays an important role in tumor cell invasion and appears to be associated with the development of the characteristic desmoplastic reaction in pancreatic cancer.

[Anxiety as a concomitant symptom of depression in the elderly]

Anxiety is a symptom frequently encountered in elderly depressed patients. It is supposed to have an unfavourable prognostic impact. We studied the frequency of psychic anxiety and its relationship to demographic, social and clinical variables in a group of 54 elderly depressed patients admitted to a gerontopsychiatric day-clinic. Severity of depression, cognitive performance, functional level, social situation and life satisfaction were studied by means of standardized instruments. In about half of the patients studied, we found significant psychic anxiety. Compared to the other depressed patients, patients with anxiety suffered more frequently from cognitive impairment and were more dissatisfied with the acceptance of their disease by other persons. They more frequently lived together with other persons in one household. When leaving psychic anxiety out of consideration as a depressive symptom, the severity of depression was not different in patients with and without anxiety. Anxious patients were equally responsive to day-clinic treatment as non-anxious patients. However, duration of treatment was considerably increased. Thus, elderly depressed patients with anxiety show particular psychosocial and clinical features and require special attention in diagnostics and treatment.

Increase of bone mineral density with sodium fluoride in patients with Crohn's disease

BACKGROUND AND AIMS

Low bone density with an increased risk of vertebral fractures is a frequent complication in inflammatory bowel disease. Since the aetiology of osteopathia in these patients is different compared to postmenopausal or steroid-induced osteoporosis, no treatment strategy is established. Supplementation of calcium and vitamin D has been shown to prevent further bone loss, but no data are available showing the anabolic effect of sodium fluoride in Crohn's disease.

METHODS

We carried out a one-year prospective clinical trial in 33 patients with chronic active Crohn's disease who were randomly assigned to receive either calcium (500 mg b.i.d.) and 1000 IU vitamin D3 only, or retarded-release sodium fluoride (25 mg t.i.d.) additionally. The diagnosis of Crohn's disease had been made at least two years ago, and all patients had received systemic high-dose steroid therapy during the previous year. Eleven of 15 patients who received calcium/vitamin D and 15 of 18 patients who additionally received sodium fluoride completed the study. The primary endpoint of the study was the increase of bone mineral density, measured by dual energy X-ray absorptiometry (DXA) after one year of treatment. Bone-specific alkaline phosphatase and osteocalcin were used as markers for bone turnover.

RESULTS

In the calcium/vitamin D only group, bone density was not significantly changed after one year of treatment, whereas in the calcium/vitamin D/fluoride group, bone density of the lumbar spine increased from -1.39+/-0.3 (Z-score, mean +/- SEM) to -0.65+/-0.3 (P<0.05) after one year of treatment. Increase of bone density was positively correlated to the osteoblastic markers bone-specific alkaline phosphatase (r = 0.53) and osteocalcin (r = 0.43).

CONCLUSIONS

Sodium fluoride in combination with vitamin D and calcium is an effective, well-tolerated and inexpensive treatment to increase lumbar bone density in patients with chronic active Crohn's disease and osteoporosis.

Platelet-derived growth factors stimulate proliferation and extracellular matrix synthesis of pancreatic stellate cells: implications in pathogenesis of pancreas fibrosis

At present, the cell-cell interactions and molecular mechanisms of pancreas fibrogenesis are largely unknown. The purpose of this study was to investigate paracrine stimulatory loops between platelets and pancreatic stellate cells (PSC). Human PSC were obtained by outgrowth from fibrotic human pancreas. Native platelet lysate (nPL) and transiently acidified platelet lysate (aPL) were added to cultured PSC (passage 4 to 7) in the absence of serum. The synthesis of collagen types I and III and c-fibronectin (cFN) was demonstrated on protein (immunofluorescence and quantitative immunoassay) and mRNA (Northern blot) level. Using sections of human pancreas with acute pancreatitis, platelet aggregates in capillaries were demonstrated by transmission electron microscopy. nPL, and to an even greater extent aPL, significantly increased the synthesis of collagen types I and III and of c-FN (120 microl/ml aPL increased collagen type I concentration in PSC supernatants by 1.99 +/- 0.17 times and c-FN of 2.49 +/- 0.28 times, mean +/- SD, n = 3). nPL and aPL also significantly stimulated cell proliferation (increased bromodeoxyuridine (BrdU) incorporation by 6.4 +/- 0.78 times and 10 +/- 0.29 times, respectively). By preincubating aPL with transforming growth factor beta (TGFbeta)- and platelet-derived growth factor (PDGF)-neutralizing antibodies and the TGFbeta-latency associated peptide, respectively, TGFbeta1 was identified as the main mediator stimulating matrix synthesis and PDGF as the responsible mitogen. Our data demonstrate that platelets contain fibrogenic mediators that stimulate proliferation (PDGF) and matrix synthesis (TGFbeta1) of cultured PSC. We suggest that platelets and PSC cooperate in the development of pancreas fibrosis.

Does maternal smoking hinder mother-child transmission of Helicobacter pylori infection?

Evidence for early childhood as the critical period of Helicobacter pylori infection and for clustering of the infection within families suggests a major role of intrafamilial transmission. In a previous study, we found a strong inverse relation between maternal smoking and H. pylori infection among preschool children, suggesting the possibility that mother-child transmission of the infection may be less efficient if the mother smokes. To evaluate this hypothesis further, we carried out a subsequent population-based study in which H. pylori infection was measured by 13C-urea breath test in 947 preschool children and their mothers. We obtained detailed information on potential risk factors for infection, including maternal smoking, by standardized questionnaires. Overall, 9.8% (93 of 947) of the children and 34.7% (329 of 947) of the mothers were infected. Prevalence of infection was much lower among children of uninfected mothers (1.9%) than among children of infected mothers (24.7%). There was a strong inverse relation of children's infection with maternal smoking (adjusted odds ratio = 0.24; 95% confidence interval = 0.12-0.49) among children of infected mothers, but not among children of uninfected mothers. These results support the hypothesis of a predominant role for mother-child transmission of H. pylori infection, which may be less efficient if the mother smokes.

Infection with Helicobacter pylori is not a major independent risk factor for stable coronary heart disease: lack of a role of cytotoxin-associated protein A-positive strains and absence of a systemic inflammatory response

BACKGROUND

There is controversy about the association between Helicobacter pylori infection and manifestations of coronary heart disease (CHD), the potential role of the more virulent H pylori strains, and whether or not a positive serostatus is related to increased levels of markers of systemic inflammation.

METHODS AND RESULTS

We assessed the prevalence of an infection with H pylori and in particular the anti-cytotoxin-associated protein A (CagA) antibody response of the more virulent strains expressing CagA in 312 patients with stable CHD and in 479 control subjects. Serological prevalence of H pylori infection (IgG titer) was significantly higher in patients than in control subjects after adjustment for age and sex (44.2% versus 31.3%, P<0.001). After adjustment for various covariates in multiple logistic regression, the odds ratio (OR) for CHD was 1.3 (95% CI, 0.9 to 1.9) given a positive IgG serostatus. The prevalence of CagA-positive strains was 27.9% in patients and 21.7% in control subjects (P=0.076 adjusted for age and sex). The OR for CHD in the fully adjusted model was 1.1 (95% CI, 0.7 to 1.7). None of the inflammatory markers (C-reactive protein, fibrinogen, plasma viscosity, or leukocytes) was significantly different according to serostatus.

CONCLUSIONS

In this large case-control study, the association of H pylori infection with stable CHD was strongly reduced and was no longer statistically significant after controlling for potential confounders. We also found no independent association between the more virulent strains and CHD. In addition, a positive serostatus was not associated with a systemic inflammatory response. Thus, these data do not support the hypothesis that infection with H pylori might be a major risk factor for stable CHD.

Inhibition of nuclear factor kappa B and induction of apoptosis in T-lymphocytes by sulfasalazine

1. Chronic inflammatory diseases have been shown to be associated with NF-kappaB activation and impaired apoptosis of immune cells. The aim of the present study was to investigate if sulfasalazine and its colonic metabolites 5-aminosalicylic acid (5ASA) and sulfapyridine affect NF-kappaB/Rel activation and viability of T-lymphocytes. 2. Sulfasalazine inhibits NF-kappaB/Rel activation in the murine T-lymphocyte cell line RBL5 using electrophoretic mobility shift assays. In transfection assays sulfasalazine treatment for 4 h inhibits kappaB-dependent transcription with an IC50 value of approximately 0.625 mM. 3. Higher doses or prolonged treatment result in cell death of T-lymphocytes in a dose- and time-dependent manner. Cell death is caused by apoptosis as judged by DNA fragmentation, annexin V and Apo 2.7 staining. Induction of apoptosis is a fast event with 50% apoptotic cells after a 4 h incubation with 2.5 mM sulfasalazine. The ED50 value for apoptosis induction after 24 h treatment was approximately 0.625 mM. 4. In contrast, 5ASA and sulfapyridine neither inhibit NF-kappaB/Rel activation nor induce apoptosis in T-lymphocytes at doses up to 5.0 mM. 5. These results demonstrate that sulfasalazine, but not 5ASA or sulfapyridine, strongly inhibits NF-kappaB activation and potently induces apoptosis in T-lymphocytes. Inhibition of NF-kappaB/Rel activation and subsequent clearance of activated T-lymphocytes by apoptosis might thus explain the beneficial effects of sulfasalazine in the treatment of chronic inflammatory disorders.

Comparison between the oral and intravenous L-[1-13C]phenylalanine breath test for the assessment of liver function

To simplify the L-[1-13C]phenylalanine breath test which is used to assess liver function the tracer is usually given orally, and CO2 production rate is estimated. In 12 healthy volunteers and 10 liver cirrhotics we compared the oral approach with i.v. tracer administration combined with measurement of individual CO2 production rate. The 13CO2/12CO2 enrichment was assessed by isotope-ratio mass spectrometry. After i.v. [1-13C]phenylalanine application exhaled 13C recovery per minute peaked within 10 minutes (controls: 0.17 +/- 0.06%; cirrhotics: 0.05 +/- 0.02%, p < 0.01). The oral approach yielded comparable separation between 30-60 minutes, with average peak values being 0.18 +/- 0.03% and 0.06 +/- 0.03% (p < 0.01), respectively. Variable gastrointestinal resorption kinetics after oral application probably causes this difference.

Metformin inhibits catecholamine-stimulated lipolysis in obese, hyperinsulinemic, hypertensive subjects in subcutaneous adipose tissue: an in situ microdialysis study

AIMS

Metformin has been reported to decrease the plasma concentrations of non-esterified fatty acids in Type 2 diabetic subjects. This study investigated the effects of metformin on basal and catecholamine-stimulated lipolysis in abdominal subcutaneous adipose tissue of obese, hyperinsulinaemic, hypertensive subjects.

METHODS

Fourteen subjects with severe obesity (12 female, twomale, age 35.4 +/- 4 years, body mass index 48.2 +/- 2 kg/m2, body fat mass 63.3 +/- 5 kg) were recruited. Glycerol and lactate concentrations were determined in the presence of metformin and after administration of catecholamines using microdialysis. Simultaneously, blood flow was assessed with the ethanol escape method.

RESULTS

Glycerol release was lowered by metformin during the 3-h experiment (P<0.01). The lipolytic activity of catecholamines was suppressed when adipose tissue was pre-treated with metformin (P<0.001). Lactate concentration increased after application of metformin (P<0.01) and catecholamines (P<0.001). Blood flow was decreased in the presence of adrenaline (P < 0.01), but this effect was abolished by metformin.

CONCLUSIONS

The present data demonstrate the effects of metformin on lipolysis in subcutaneous adipose tissue in vivo. In the large body fat mass of obese subjects, a reduction of lipolysis in adipose tissue may contribute to a decrease of VLDL synthesis in the liver resulting in a lowered plasma triglyceride concentration.

Prospective evaluation of brush cytology of biliary strictures during endoscopic retrograde cholangiopancreatography

BACKGROUND AND STUDY AIMS

Cytological methods may be used to differentiate benign from malignant biliary strictures. We evaluated the diagnostic accuracy of an endobiliary cytotechnique which can easily be performed during endoscopic retrograde cholangiopancreatography.

PATIENTS AND METHODS

Cytological samples were obtained by brushing biliary strictures via a guide wire in 86 patients with strictures of unknown status. Samples were classified by an expert cytologist as normal (including reactive cells), severely dysplastic (atypical cells suspicious of malignancy) and clearly malignant. A final diagnosis was achieved in 78 patients based on intraoperative findings and histological investigation, autopsy or prolonged follow-up. Strictures were malignant in 57 cases (31 pancreatic carcinoma, 20 cholangiocarcinoma, 6 others) and benign in 21 cases (11 chronic pancreatitis, 5 chronic nonspecific inflammation, 5 others).

RESULTS

The overall results for brush cytological investigation were sensitivity 56.1%, specificity 90.5%, positive predictive value 94.1%, negative predictive value 43.2 %, and accuracy 65.4 %. Sensitivity was significantly higher (P<0.005) in cholangiocarcinoma (80%) compared with pancreatic carcinoma (35.5%). The overall specificity of less than 100 % resulted from dysplasia in two patients with chronic pancreatitis and inflammatory mass. No procedure-related complications occurred.

CONCLUSIONS

Brush cytology is helpful for differentiating between benign and malignant biliary strictures, especially in suspected cholangiocarcinoma. Dysplastic cells may occur in the absence of malignancy and their presence should therefore be interpreted cautiously.

Mild cognitive impairment in old-age depression is associated with increased EEG slow-wave power

Reversible dementia in geriatric depression is known to be a risk factor for irreversible dementia. Whether just mild cognitive deficits in elderly depressed patients hold a similar risk is not known yet. It may be suggested that elderly depressed patients with mild cognitive deficits, who are prone to develop dementia, show EEG alterations similar to those observed in demented patients. We studied the relationships between cognitive performance, severity of depressive symptoms and quantitative EEG parameters in 31 unmedicated, nondemented, depressed patients aged 60 years or more. Twenty-one of the patients showed a cognitive performance characteristic of mild cognitive impairment. In these patients, the mean delta and theta power was significantly higher than in the patients without cognitive impairment. Total delta power was negatively correlated with cognitive performance. There was no relationship between cognitive performance or EEG parameters and the severity of depression.

Lipopolysaccharide-activated macrophages stimulate the synthesis of collagen type I and C-fibronectin in cultured pancreatic stellate cells

We have recently identified and characterized pancreatic stellate cells (PSC) in rats and humans (Gastroenterology 1998, 15:421-435). PSC are suggested to represent the main cellular source of extracellular matrix in chronic pancreatitis. Now we describe a paracrine stimulatory loop between human macrophages and PSC (rat and human) that results in an increased extracellular matrix synthesis. Native and transiently acidified supernatants of cultured macrophages were added to cultured PSC in the presence of 0.1% fetal calf serum. Native supernatants of lipopolysaccharide-activated macrophages stimulated the synthesis of collagen type I 1.38 +/- 0.09-fold of control and c-fibronectin 1.89 +/- 0.18-fold of control. Transiently acidified supernatants stimulated collagen type I and c-fibronectin 2.10 +/- 0.2-fold and 2.80 +/- 0.05-fold of control, respectively. Northern blot demonstrated an increased expression of the collagen-I-(alpha-1)-mRNA and fibronectin-mRNA in PSC 10 hours after addition of the acidified macrophage supernatants. Cell proliferation measured by bromodeoxyuridine incorporation was not influenced by the macrophage supernatants. Unstimulated macrophages released 1.97 pg TGFbeta1/microgram of DNA over 24 hours and lipopolysaccharide-activated macrophages released 6.61pg TGFbeta1/microgram of DNA over 24 hours. These data together with the results that, in particular, transiently acidified macrophage supernatants increased matrix synthesis, identify TGFbeta as the responsible mediator. In conclusion, our data demonstrate a paracrine stimulation of matrix synthesis of pancreatic stellate cells via TGFbeta1 released by activated macrophages. We suggest that macrophages might play a pivotal role in the development of pancreas fibrosis.

Expression of the highly conserved RNA binding protein KOC in embryogenesis

The human KOC gene which is highly expressed in cancer shows typical structural features of an RNA binding protein. We analyzed the temporal and spatial expression pattern of KOC in mouse embryos at different gestational ages. The expression of KOC seems to be ubiquitous at early stages. During advanced gestation highest KOC expression occurs in the gut, pancreas, kidney, and in the developing brain. The expression pattern of KOC was compared to its Xenopus homologue Vg1-RBP during frog development. Similar expression was found in these organs suggesting an important functional role of the homologous proteins in embryonic development.

A phase II study of weekly 24-h infusion of high-dose 5-fluorouracil in advanced pancreatic cancer

No single agent or combination chemotherapy protocol, with the exception of gemcitabine, has so far proven superior to standard bolus 5-fluorouracil regimes for the treatment of advanced pancreatic cancer. The present phase II trial was designed to study whether the effectivity of 5-fluorouracil can be improved with a weekly high-dose 5-fluorouracil schedule. 26 patients with cytologically or histologically verified, metastasized (n = 21) or locally advanced (n = 5) previously untreated adenocarcinoma of the pancreas were included in this study. Treatment consisted of weekly applications of 2,600 mg/m2 5-fluorouracil as 24-h infusion on days 1, 8, 15, 22, 29, 36. Treatment was repeated at day 50 and was continued until disease progression. Primary endpoints of the study were response rates and toxicity, secondary endpoints were survival and clinical benefit in terms of performance status, body weight and analgesia consumption. Toxicity of the regimen was mild with only four instances of grade-3 toxicity. Response rates were 8% (95% CI = 1.2-13.7) with two partial remissions. Improvement of at least one parameter of clinical benefit for > or = four weeks was observed for 11.5% of the study patients. The most prominent effect was a transient stabilization of objective tumor measurements (48% [95% CI = 27.8-68.7]) and individual parameters of clinical benefit (50-75%). Median survival was 248 days (95% CI = 164-459) for all patients included in the study. The present study indicates that the high-dose 5-fluorouracil regimen shows weak activity in advanced pancreatic cancer which seems comparable to gemcitabine.

Invasion and metastasis in pancreatic cancer

Understanding the molecular mechanisms of invasion and metastasis is crucial for the development of novel therapeutic strategies to treat metastases. Considerable studies revealed that the establishment of metastasis is the final outcome of a series of processes such as tumor growth, angiogenesis, tumor cell detachment and invasion of extracellular matrix. Each step of this multistep process is essential for tumor cell survival and establishment of secondary lesions and is regulated by interactions of tumor cells with host microenvironment. This review is focused on the molecular mechanisms involved in the regulation of this processes. The central role of adhesion molecules and ECM degrading proteinases in disruption of cell-cell and cell-ECM associations as well as degradation of extracellular matrix and basement membranes is emphasized.

TGFbeta and the extracellular matrix in pancreatitis

Regeneration from cerulein-induced pancreatitis is accompanied by a transient synthesis and deposition of extracellular matrix components in the rat pancreas. To study the involvement of transforming growth factor beta1 (TGFbeta1), one of the most potent modulators of the extracellular matrix, in the process of pancreatic regeneration we examined the expression of this gene on the transcript and protein level in pancreata of rats sacrificed 0 hours, 24 hours, 2, 3, 5, 7 days after a 12 hour infusion of maximal doses of cerulein (10 microg kg(-1) h(-1)). TGFbeta1 protein increased twofold after 24 hours and 48 hours and returned to control values 7 days after induction of pancreatitis, while TGFbeta1-mRNA reached maximal values (3-fold over controls) after 2 days. The largest amount of TGFbeta1 mRNA was found in pancreatic acinar cells and in stromal cells. To verify the functional implication of TGFbeta overexpression in regulating extracellular matrix remodeling during regeneration from acute pancreatitis, rats were treated with 3 injections of neutralizing antibody against TGFbeta1 given 30 min before, and 24 hours and 48 hours after the start of infusion. In rats treated with maximal doses of cerulein and TGFbeta antibodies, pancreatic hydroxyproline content and expression of collagens I and III and of TGFbeta1 were significantly reduced. These results provide evidence that transforming growth factor beta1 among other cytokines is involved in the regulation of extracellular matrix remodeling in the rat pancreas during regeneration from cerulein-induced acute pancreatitis. In addition, there is evidence in the literature that application of recombinant TGFbeta after recurrent episodes of acute cerulein-induced pancreatitis promotes pancreatic fibrosis (3). Thus, TGFbeta is a regulator of extracellular matrix remodeling in the pancreas, and may be an important promoting factor in the pathogenesis of chronic pancreatitis. This hypothesis is supported by data in the literature showing enhanced TGFbeta expression in human chronic pancreatitis (2) and development of fibrosis and inflammation in pancreata of transgenic mice overexpressing TGFbeta1 (3).

Genomic imprinting of IGF-II and H19 in adult human pancreatic tissues

BACKGROUND/AIM

Genomic imprinting is a chromosomal modification causing differential expression of maternal and paternal alleles. Loss of imprinting (LOI) of IGF-II and H19 has been suggested to be an early oncogenic event in cancerogenesis. Aim of the present study was to describe the status of IGF-II and H19 imprinting in adult human pancreatic tissues.

METHODS

Allele-specific gene expression was studied using RNA and DNA from human pancreatic cancer, chronic pancreatitis, and normal pancreas tissues heterozygous for ApaI (IGF-II) or RsaI (H19) restriction fragment length polymorphism. Reverse-transcriptase polymerase chain reaction products were digested with either ApaI or RsaI and analyzed on agarose gels to study the status of allelic expression. The expression level of H19 and IGF-II was studied on Northern blots or by polymerase chain reaction.

RESULTS

H19 was imprinted in normal pancreas and in chronic pancreatitis. H19 LOI was observed in 1 of 4 informative cancer tissues and was not associated with increased H19 transcript levels. Biallelic expression of IGF-II was found in 6 of 10 informative cancer tissues and in 6 of 9 informative normal tissues. In chronic pancreatitis, the IGF-II gene was imprinted in all informative samples. IGF-II mRNA was not overexpressed in the tissues showing LOI.

CONCLUSION

Low frequencies of H19 LOI and the lack of correlation between biallelic expression and overexpression observed for both H19 and IGF-II suggest that LOI of H19 and IGF-II is not a relevant oncogenic factor during human exocrine pancreatic cancerogenesis.

Caerulein-induced NF-kappaB/Rel activation requires both Ca2+ and protein kinase C as messengers

The eukaryotic transcription factor NF-kappaB/Rel is activated by a large variety of stimuli. We have recently shown that NF-kappaB/Rel is induced during the course of caerulein pancreatitis. Here, we show that activation of NF-kappaB/Rel by caerulein, a CCK analog, requires increasing intracellular Ca2+ levels and protein kinase C activation. Caerulein induces a dose-dependent increase of nuclear NF-kappaB/Rel binding activity in pancreatic lobules, which is paralleled by degradation of IkappaBalpha. IkappaBbeta was only slightly affected by caerulein treatment. Consistent with an involvement of Ca2+, the endoplasmic reticulum-resident Ca2+-ATPase inhibitor thapsigargin activated NF-kappaB/Rel in pancreatic lobules. The intracellular Ca2+ chelator TMB-8 prevented IkappaBalpha degradation and subsequent nuclear translocation of NF-kappaB/Rel induced by caerulein. BAPTA-AM was less effective. Cyclosporin A, a Ca2+/calmodulin-dependent protein phosphatase (PP2B) inhibitor, decreased caerulein-induced NF-kappaB/Rel activation and IkappaBalpha degradation. The inhibitory effect of bisindolylmaleimide suggests that protein kinase C activity is also required for caerulein-induced NF-kappaB/Rel activation. These data suggest that Ca2+- as well as protein kinase C-dependent mechanisms are required for caerulein-induced NF-kappaB/Rel activation.