P53 mutation but not p16/MTS1 mutation occurs in intraductal papillary mucinous tumors of the pancreas.

BACKGROUND/AIMS: Intraductal papillary mucinous tumors of the pancreas are rare lesions, which typically show a benign clinical course. However, some of these tumors have a malignant nature and grow in an invasive manner. The purpose of the study was to determine the prevalence of p53-, p16/MTS1- and K-ras mutations in benign and malignant intraductal papillary mucinous tumors with intent to value their importance for tumor progression. METHODOLOGY: Thirteen different archival tumor specimens were obtained at the Department of Pathology, University of Ulm. Three cases showed an invasive component of the tumor. Genomic DNA was extracted after laser capture microdissection of tumor cells from paraffin-embedded tissue sections. The corresponding sequences of p53 (exon 5, 6, 7, 8) and p16/MTS1 (exon 2) were amplified by polymerase chain reaction and subjected to single strand conformation polymorphism analysis. Codon 12 of K-ras was analyzed by the enrichment polymerase chain reaction-restriction fragment length polymorphism method. Positive samples were further investigated by sequencing. RESULTS: K-ras mutations occurred in benign and malignant intraductal papillary mucinous tumors (4/13), whereas an alteration of the coding p53 gene sequence could only be detected in the intraductal and invasive component of one malignant tumor. None of the tissue specimens revealed mutations in exon 2 of p16/MTS1. CONCLUSIONS: In contrast to K-ras mutations, alterations in the p53 gene may characterize ductal papillary mucinous carcinomas, which could be of major interest for their early diagnosis. The lack of mutations in the p16/MTS1 gene suggests that other genes may be involved in the formation of intraductal papillary mucinous neoplasias.

Epidermal growth factor induces cyclin D1 in human pancreatic carcinoma: evidence for a cyclin D1-dependent cell cycle progression.

INTRODUCTION: We recently showed that cyclin D1 is overexpressed in human pancreatic carcinoma cells, and that this overexpression correlates significantly with a poor prognosis. AIMS: To assess the interrelations of epidermal growth factor (EGF), EGF receptor (EGFR), and cyclin D1 in human pancreatic carcinoma. METHODOLOGY AND RESULTS: In pancreatic carcinoma cell lines (BxPC-3, AsPC-1), cell cycle analysis revealed an increase in cells in the S/G1 phase between 18 and 30 hours after stimulation with 50 ng/mL EGF. Cyclin D1 mRNA increased after 2 hours, corresponding to an increase in cyclin D1 protein, with the maximum level between 7.5 and 10 hours after stimulation, as demonstrated by Western blot analysis. We performed immunohistochemical analysis on 61 adenocarcinoma tissues for the expression of EGF, EGFR, and cyclin D1 and demonstrated an overexpression in the tumor cells in 51%, 54%, and 62.3%, respectively, whereas normal human pancreas stained negative for all of the three factors. Interestingly, EGF and EGFR expression correlated significantly with the cyclin D1 expression in human pancreatic tumor cells (p < 0.001 and p < 0.01, respectively). CONCLUSION: These results demonstrate that cyclin D1 overexpression in the tumor cells of pancreatic carcinoma tissue is at least partly dependent on the mitogenic effects of EGF signaling through the EGFR.

Low serum levels of CD44, CD44v6, and neopterin indicate immune dysfunction in chronic pancreatitis.

INTRODUCTION: In autoimmune diseases, malignancies, and inflammatory conditions, a correlation of serum levels of CD44, interleukin-2 receptor (IL-2r), and neopterin with disease activity could be shown. AIMS: To assess the immune parameters in chronic pancreatitis in correlation to clinical data to evaluate the potential role of immune dysfunction as a risk factor. METHODOLOGY: Levels of IL-2r, sCD44, sCD44v6, and neopterin were measured using the enzyme-linked immunosorbent assay in 63 patients with chronic pancreatitis who underwent surgery between 1992 and 1995 in our institution. Clinical data were evaluated prospectively before surgery, and a follow-up investigation was conducted in 1997. RESULTS: Mean serum levels of CD44, CD44v6, and neopterin were significantly lower in patients with chronic pancreatitis compared with the control group. The mean level of IL-2r was also lower in chronic pancreatitis, but this difference was not significant. However, no influence of immunosuppressive factors such as alcohol consumption, cigarette smoking, or diabetes could be detected on the levels of IL-2r, CD44, CD44v6, and neopterin. CONCLUSION: In accordance with other diseases of reduced immunoreactivity, depressed serum levels of biomarkers in chronic pancreatitis are caused by reduced T-lymphocyte and macrophage activation. By ruling out a significant influence of concomitant immunosuppressive factors, we conclude that the inflammatory process itself is the source of the depressed immune function, which might be restored by surgical resection.

Overexpression of caspase-1 (interleukin-1beta converting enzyme) in chronic pancreatitis and its participation in apoptosis and proliferation.

Caspase-1, formerly designated interleukin-1beta converting enzyme, was the first described member of a group of cysteine proteases called caspases. It is suggested that caspases play an important role in apoptosis, but recent observations could show that caspase-1 might also be involved in cellular proliferation. We investigated the expression of caspase-1 in 38 chronic pancreatitis tissues, six pancreatitis tissues from patients with pancreatic carcinoma and nine normal pancreatic tissues by immunohistochemistry. Western blot analysis was used to confirm the immunohistochemical findings. We found a clear expression of caspase-1 in chronic pancreatitis, but not in normal pancreatic tissues. Interestingly, we found expression of caspase-1 in three distinct morphologic compartments: (i) in atrophic acinar cells (31 of 35; 89%), (ii) proliferating cells of ductal origin (33 of 38; 87%), and (iii) in acinar cells redifferentiating to form tubular structures (26 of 31; 83%). These immunohistochemical findings were confirmed by Western blot analysis, which showed an expression of caspase-1 in 85% of the tissues. No correlation was found between any of the examined clinicopathologic features and the caspase-1 expression in chronic pancreatitis. In conclusion, the expression of caspase-1 is a frequent event in chronic pancreatitis and its distribution pattern may reflect two functions of this protease: on one hand its participation in the apoptotic pathway in atrophic acinar cells and, on the other hand, its role in proliferation and differentiation in proliferating duct cells.

Reduced membranous and ectopic cytoplasmic expression of beta -catenin correlate with cyclin D1 overexpression and poor prognosis in pancreatic cancer.

Beta-catenin is a component of the E-cadherin-catenin cell adhesion complex. It plays also a role in intracellular signaling and can function as an oncogene when it binds to the T-cell factor 4 (Tcf4)-binding site in the promoter region of cyclin D1 and transactivates genes after translocation to the nucleus. We evaluated the immunohistochemical expression pattern of beta-catenin in relationship with cyclin D1 overexpression, tumor grade, clinicopathologic parameters and patients' survival in 43 ductal adenocarcinomas of the pancreas and 5 normal pancreatic tissues. We were able to show that, both reduced membranous beta-catenin expression (25 of 43, 58.1%) and accumulation of beta-catenin in the cytoplasm (28 of 43, 65.1%) correlated significantly with cyclin D1 overexpression (both p < 0.0005). Furthermore, we could show a clear correlation between reduced membranous expression and ectopic cytoplasmic expression of beta-catenin (p < 0.0005). Among patients with carcinomas showing no cytoplasmic expression, the 1-year survival was 86.6% whereas among patients with carcinomas showing cytoplasmic expression only 35.7% survived 1 year (p < 0.01). Co-precipitation experiments revealed reduced beta-catenin bound to the E-cadherin-catenin complex in pancreatic tumor tissues compared with normal pancreatic tissues. These results suggest that beta-catenin may be involved in the tumorigenesis of pancreatic cancer and exhibited its effects mainly by the transactivation of cyclin D1.

Distributional and functional alterations of immunocompetent peripheral blood lymphocytes in patients with chronic pancreatitis.

OBJECTIVE: To investigate whether the chronic inflammatory process in patients with chronic pancreatitis affects their immune function. SUMMARY BACKGROUND DATA: Chronic pancreatitis is a chronic inflammatory disease of the exocrine pancreas. In approximately 30% of patients, an inflammatory mass of the pancreatic head is found, representing an indication for surgery. METHODS: This study comprised 28 patients with chronic pancreatitis. Sixteen patients were also reevaluated 1 year after resection of the pancreatic head for chronic pancreatitis. RESULTS: Compared with an age- and gender-matched control group, the number of CD3(+) cells was significantly increased in patients with chronic pancreatitis, with an increase of both CD3(+)CD4(+) and CD3(+)CD8(+) cells. The number of natural killer cells or B lymphocytes did not differ between the patients and the control group. After stimulation with phytohemagglutinin or anti-CD3 antibodies, the blastogenic response was significantly attenuated in the patients with chronic pancreatitis. One year after resection of the pancreatic head for chronic pancreatitis, the distribution and the blastogenic response to phytohemagglutinin and anti-CD3 antibodies had returned to normal compared with preoperative values. CONCLUSION: The chronic inflammatory process in chronic pancreatitis markedly affects the distribution and function of peripheral immunocompetent blood cells, and elimination of the chronic inflammatory focus by pancreatic head resection restores the suppressed immune function in these patients.

Inhibition of caspase-1 induces cell death in pancreatic carcinoma cells and potentially modulates expression levels of bcl-2 family proteins.

Caspase-1 (interleukin-1beta-converting enzyme) is reported to play an important role in the regulation of apoptosis. We investigated the inhibition of caspase-1 by the cell permeable caspase-1 inhibitor Ac-AAVALLPAVLLALLAP-YVAD.CHO in pancreatic carcinoma cells. Inhibition of caspase-1 induced a non-apoptotic/"necrotic-like" cell death in AsPC-1, BxPC-3, MiaPaCa-2 and Panc-1 cells. Expression levels of bcl-2 and bax were up-regulated in caspase-1 inhibitor-treated cells while that of bcl-x(L) remained unaltered. Our observations support our previous findings that caspase-1 is potentially involved in anti-apoptotic processes in pancreatic carcinoma.

Overexpression of caspase-1 in pancreatic disorders: implications for a function besides apoptosis.

The caspases are known to play a crucial role in the triggering and execution of apoptosis in a variety of cell types. We assessed the expression of caspase-1 in 42 pancreatic cancer tissue samples, 38 chronic pancreatitis specimens, and nine normal pancreatic tissues by immunohistochemistry and Western blot analysis. We found a clear overexpression of caspase-1 in both disorders, but differences in the expression patterns in distinct morphologic compartments. Pancreatic cancer tissue showed a clear cytoplasmatic overexpression of caspase-1 in tumor cells in 71% of the tumors, whereas normal pancreatic tissue showed only occasional immunoreactivity. In chronic pancreatitis an overexpression of caspase-1 was found in atrophic acinar cells (89%), hyperplastic ducts (87%), and dedifferentiating acinar cells (84%). Although in atrophic cells a clear nuclear expression was found, hyperplastic ducts and dedifferentiating acinar cells showed clear cytoplasmic expression. Western blot analysis revealed a marked expression of the 45 kDa precursor of caspase-1 in pancreatic cancer and chronic pancreatitis (80% and 86%, respectively). Clear bands at 30 kDa, suggested to represent the p10-p20 heterodimer of active caspase-1, were found in 60% of the cancer tissue and 14% of the pancreatitis tissue specimens. Since we found a highly significant correlation between cytoplasm overexpression of caspase-1 in pancreatic cancer and overexpression of the known prognostic factors cyclin D1, epidermal growth factor, and epidermal growth factor receptor, it is plausible that caspase-1 has a yet unknown function in proliferative processes in addition to its well-known role in the apoptotic pathway.

Glutathione depletion causes cell growth inhibition and enhanced apoptosis in pancreatic cancer cells.

BACKGROUND: Recent studies have demonstrated that various tumors express enhanced levels of the radical scavenger glutathione (GSH). Moreover, there are grounds for claiming that GSH plays a crucial role in cell proliferation and tumor resistance. In the current study, we investigated the relation between cell growth and GSH levels in the pancreatic adenocarcinoma cell line, AsPC-1, and the significance of GSH in tumor resistance to chemotherapy. METHODS: Cell growth in AsPC-1 was initiated through transforming growth factor-alpha (TGF-alpha) or fetal calf serum (FCS). Then, cell cycle, cell proliferation, and cellular GSH content were analyzed at different times in the presence or absence of buthionine sulfoximine (BSO). The impact of GSH on chemotherapy-induced apoptosis was studied using 5-fluorouracil or melphalan in the presence or absence of BSO. Finally, we compared the GSH content of 15 pancreatic tumor specimens with 10 normal pancreatic tissue specimens. RESULTS: Analysis of GSH in pancreatic tissues demonstrated increased GSH levels in cancerous compared with normal tissue (17.5 +/- 2.3 vs. 8. 8 +/- 1.4 nmol/mg protein; P < 0.004). Incubation of AsPC-1 with TGF-alpha or FCS resulted in cell proliferation and cell cycle activity, whereas GSH content was not altered. Incubation of GSH-depleted cells with TGF-alpha did not stimulate cell growth. In addition, GSH-depletion resulted in an increased rate of apoptosis after melphalan (6.3 +/- 0.3 % vs. 11.2 +/- 0.3 %; P < 0.001), but not after 5-fluorouracil treatment. CONCLUSIONS: Taken together, our results show enhanced GSH levels in pancreatic carcinoma and an essential role of GSH in cell proliferation and in resistance of AsPC-1 cells. Therefore, GSH-depletion may improve the efficacy of adjuvant therapy in pancreatic carcinoma.

CD44v6 cell surface expression is a common feature of macrophages and macrophage-like cells - implication for a natural macrophage extravasation mechanism mimicked by tumor cells.

Soluble CD44standard (sCD44s) and CD44v6 (sCD44v6) cannot only be detected in sera of patients with pancreatic carcinoma but also of healthy blood donors. To investigate whether sCD44s and sCD44v6 are derived from white blood cells, we stimulated whole blood with phytohemagglutinin and interleukin-2, which induced expression of CD44v6 only on monocytes. For further investigations, we used the promyelocytic leukemia cell line Hl-60. Only Hl-60 cells differentiating along the macrophage pathway showed increased expression of CD44s and CD44v6. Furthermore, only macrophages showed increased secretion of sCD44s and sCD44v6. Our data suggest that CD44s and CD44v6 are common adhesion molecules on macrophages and macrophage-like cells.

The role of polymorphonuclear leukocytes and oxygen-derived free radicals in experimental acute pancreatitis: mediators of local destruction and activators of inflammation.

Using a retrograde infusion sodium taurocholate pancreatitis model in the rat treatment with oxygen radical scavengers or monoclonal anti-ICAM-1 antibody decreased tissue damage and polymorphonuclear leukocytes (PMN) infiltration. Scavengers or anti-ICAM-1 treatment attenuated the activating capacity of blood PMNs following zymosan stimulation. The local production of oxygen free radicals in the pancreas by systemic infusion of hypoxanthine and regional infusion of xanthine oxidase did not induce acute pancreatitis, although an increase of infiltrating PMNs was observed. Our data suggest that oxygen free radicals and infiltrating PMNs aggravate acute pancreatitis and that both are important mediators of local destruction and systemic activation of PMNs.

Inhibition of epidermal growth factor-induced interleukin-1beta-converting enzyme expression reduces proliferation in the pancreatic carcinoma cell line AsPC-1.

It is suggested that interleukin-1beta-converting enzyme (ICE) and ICE-related proteases play an important role in programmed cell death (apoptosis). We investigated ICE expression in the human pancreatic carcinoma cell line AsPC-1 after stimulation with epidermal growth factor and found a time-dependent expression of active ICE induced by epidermal growth factor. Interestingly, ICE expression does not lead to apoptosis. Cell cycle analyses revealed that acetyl-Tyr-Val-Ala-Asp-chloromethylketone-specific and acetyl-Ala-Ala-Val-Ala-Leu-Leu-Pro-Ala-Val-Leu-Leu-Ala-Leu-Leu-Ala-Pro-T yr-Val-Ala-Asp-aldehyde-specific cell-permeable inhibitors of ICE significantly reduced the proliferation of AsPC-1 cells, which suggested a positive influence of ICE on the proliferation in human pancreatic carcinoma cells.

p53 in relation to therapeutic outcome of locoregional chemotherapy in pancreatic cancer.

Since celiac artery infusion (CAI) led to an increase in survival in palliative chemotherapy in pancreatic cancer, we treated 26 patients with adjuvant CAI following resection for advanced pancreatic cancer. Catheters were placed angiographically into the celiac artery and remained there for five consecutive days. One cycle of chemotherapy consisted of mitoxantrone, 5-fluorouracil (5-FU), folinic acid, and cis-platinum. This treatment was repeated five times in monthly intervals. Median survival times in patients who received CAI are 21 months for all patients, whereas in patients who did not receive adjuvant treatment median survival is 10.5 months. In all patients p53 expression of the carcinomas was determined by immunohistochemistry. In 11/26 patients a p53 overexpression was observed. Although p53 overexpression turned out to be associated with poor prognosis in the patients who underwent adjuvant regional cancer treatment, p53 is not a sufficient prognostic parameter in pancreatic carcinoma, since p53 overexpression was more frequent in undifferentiated tumors and in palliative resected tumors.

Basal expression and cytokine induction of intercellular adhesion molecule-1 in human pancreatic cancer cell lines.

Although expression of intercellular adhesion molecule-1 (ICAM-1) expression has been demonstrated in many human malignancies, very little is known about the ICAM-1 expression in human pancreatic cancer. We have examined ICAM-1 expression in pancreatic cancer cell lines and the induction of ICAM-1 in these cells by flow cytometry. The degree of baseline ICAM-1 expression was most significant in Panc-1, followed by PMH-2, Capan-2, Bx-PC-3, Capan-1, and PMH-3 in that order. PaCa-2 and AsPC-1 showed very low levels of baseline ICAM-1 expression. After tumor necrosis factor alpha and interferon gamma stimulation, five cell lines exhibited distinct ICAM-1 induction. The degree of induction was remarkable in AsPC-1 (32-fold), and moderate in PMH-3 (6.5-fold), PaCa-2 (3.2-fold), Capan-1 (1.6-fold), and BxPC-3 (1.5-fold). The ICAM-1 expression levels of PMH-2 and Capan-2 after stimulation were nearly the same as those before stimulation (1.2-fold and 1.1-fold, respectively). These results suggest that ICAM-1 is overexpressed and inducible by tumor necrosis factor alpha and interferon gamma in pancreatic cancer cell lines.

Serum and correspondent tissue measurements of epidermal growth factor (EGF) and epidermal growth factor receptor (EGF-R). Clinical relevance in pancreatic cancer and chronic pancreatitis.

CONCLUSION: The results of this study show that routine measurements of epidermal growth factor (EGF) and epidermal growth factor receptor (EGF-R) cannot improve screening for pancreatic cancer despite the frequently present tissue overexpression. Both values fail to reveal this malignancy in a serum test. Patients with chronic pancreatitis exhibit no or very low concentrations of EGF. In cases where preoperative diagnosis is difficult the noninvasive EGF and EGF-R serum measurements may be helpful in discriminating between pancreatic cancer and chronic pancreatitis. BACKGROUND: EGF and EGF-R are frequently overexpressed in the tissue of patients suffering from ductal pancreatic cancer and to lesser degree in patients with chronic pancreatitis. The aim of this study was to determine the value of serum measurements in these patients to detect malignant pancreatic disease. In cases of pancreatic cancer, the tissue expression of EGF and EGF-R was evaluated by immunohistochemistry. METHOD: Thirty-five patients with chronic pancreatitis and 31 patients with pancreatic cancer were evaluated; 71 patients admitted for routine surgery (hernia repair, cholecystectomy, goiter surgery) served as controls. RESULTS: EGF and EGF-R values were not significantly different in pancreatic cancer as compared to controls and did not correlate with other tumor markers (CA 19-9, carcinoembryonic antigen [CEA], tumor polypeptide antigen [TPA]) or with the stage of the disease. Fourteen patients (67%) with pancreatic cancer displayed tissue overexpression for EGF and 11 patients for EGF-R (52%). These patients, however, also failed to exhibit any significant pathological changes in serum concentration. In chronic pancreatitis, EGF and EGF-R were significantly decreased as compared to pancreatic cancer and controls. This was an unexpected finding. There was a positive correlation to clinical exocrine insufficiency.

Increased angiogenin expression in obstructive chronic pancreatitis surrounding pancreatic cancer but not in pure chronic pancreatitis.

We previously demonstrated the increased expression of angiogenin (ANG) in pancreatic cancer and its relation to cancer aggressiveness; however, the expression patterns and the roles of angiogenin in chronic pancreatitis are still unknown. We investigated the expression of ANG both in the tissues and in the sera of chronic pancreatitis patients (pure chronic pancreatitis) by using in situ hybridization, Western blot analysis, and enzyme-linked immunosorbent assay. In situ hybridization revealed no detectable ANG messenger RNA (mRNA) signals in all tissues of pure chronic pancreatitis and normal pancreas. Only a small amount of protein band expression was obtained in all of the protein lysates of pure chronic pancreatitis and normal pancreas. Accordingly, there was no significant difference between the mean serum ANG concentration of chronic pancreatitis patients (352.1+/-72.5 ng/ml) and that of healthy volunteers (357.6+/-45.2 ng/ml). By contrast, acinar cells and interstitial fibroblasts in the tissues surrounding pancreatic cancer showed increased ANG mRNA expression. Strong protein band expression was obtained in the protein lysates of pancreatic cancer surrounding tissue, and mean serum ANG concentration was increased in pancreatic cancer patients. These findings suggest that ANG expression is increased in pancreatic cancer surrounding tissue but is not increased in pure chronic pancreatitis, and that ANG is potentially involved in the pancreatic cancer microenvironment rather than the establishment of pure chronic pancreatitis.

Levels of serum neopterin are increased in pancreatic cancer patients and correlate with the prognosis.

UNLABELLED: Neopterin has been recognized as a valid marker for cellular immune activation. Raised neopterin levels indicate the stimulation of macrophages and indirectly T-cell activation. So far no data is available on serum neopterin in pancreatic cancer patients. PATIENTS: In this prospective clinical study serum neopterin values were evaluated in 83 patients with adenocarcinoma of the pancreas (PC), 47 patients with chronic pancreatitis (CP), 8 patients with cystadenocarcinoma (CA) of the pancreas and 24 healthy controls (HC). RESULTS: Serum neopterin was significantly elevated in PC (p < 0. 05) and CA (p < 0.04) as compared to HC. There was no difference found between CP and HC. Pancreatic cancer patients with neopterin levels above 2 pmol/ml had a significantly better survival (p < 0. 05) regardless of stage. In stage III and IV (UICC) this difference was highly significant (p < 0.001). Serum levels of neopterin in resectable patients were also significantly correlated with increased survival and in multivariate analysis proved to be an independent prognostic factor. Neopterin in PC was neither correlated with sex, resectability nor with CA 19/9 and CEA. CONCLUSIONS: Patients suffering from PC who did show activated cellular immune response reflected in elevated neopterin levels above 2 pmol/ml had a significantly better prognosis regardless of tumor stage. In advanced stages elevated neopterin concentrations were significantly associated with increased survival. Cellular immune response seems to influence survival in these advanced stages to a higher degree as expected. These findings underline the possibility for supportive immunotherapy in this patient group.

Increased oxidative stress in the RAW 264.7 macrophage cell line is partially mediated via the S-nitrosothiol-induced inhibition of glutathione reductase.

We investigated whether endogenously or exogenously produced nitric oxide (NO) can inhibit cellular glutathione reductase (GR) via the formation of S-nitrosothiols to decrease cellular glutathione (GSH) and increase oxidative stress in RAW 264.7 cells. The specificity of this inhibition was demonstrated by addition of a NO-synthase inhibitor, and met- or oxyhemoglobin. Using isolated GR we found that only certain NO donors inhibit this enzyme via S-nitrosothiol. Furthermore, we found that cellular GSH decrease is paralleled by an increase of superoxide anion production. Our results show that the GR enzyme is a potential target of S-nitrosothiols to decrease cellular GSH levels and to induce oxidative stress in macrophages.

The splice-pattern of CD44 is altered in chronic pancreatitis exhibiting dysplastic changes.

Recent studies have shown that several splice variants of CD44, might be involved in tumor progression. Since chronic pancreatitis is suggested to be a risk factor for pancreatic cancer we investigated the splice pattern of CD44 in chronic pancreatitis to elucidate the role of CD44 in pancreas tumorigenesis. The expression of CD44-isoforms was examined in 40 specimens of chronic pancreatitis and 12 specimens of normal pancreas by immunohistochemistry, Westernblotting and exon specific RT-PCR. Pancreatic cancer tissue from two patients who developed pancreatic cancer 2 and 3 years following surgery for chronic pancreatitis were analyzed. Strong expression of CD44s was found in all cells, whereas the expression of CD44v6 was restricted to ductal cells. Westernblotting revealed an overexpression of CD44v6 in chronic pancreatitis as compared to normal pancreas. Exon specific analysis revealed an altered splice pattern of CD44, similar to that in pancreatic cancer, in 12.5% of the chronic pancreatitis specimens. Both patients who developed pancreatic cancer after chronic pancreatitis exhibited this altered splice pattern in both, chronic pancreatitis and pancreatic cancer. These results suggest that variant forms of CD44-mRNA might be expressed in early dysplastic alterations in chronic pancreatitis.

Nitric oxide-induced apoptosis in human pancreatic carcinoma cell lines is associated with a G1-arrest and an increase of the cyclin-dependent kinase inhibitor p21WAF1/CIP1.

Nitric oxide (NO) is a messenger molecule with various biological activities including DNA damage. In the present study, we examined the influence of endogenously produced NO on human pancreatic cell lines. In response to cytokine stimulation (tumor necrosis factor alpha, IFN-gamma, and interleukin 1beta), human pancreatic carcinoma cell lines expressed the inducible NO synthase that synthesizes NO, detectable as nitrate and nitrite in the culture supernatants. Endogenously produced NO induced apoptosis in all of the tested pancreatic carcinoma cell lines. In cell cycle analysis, endogenous production of NO revealed a G1-arrest in all of the tested cell lines. This G1-arrest was blockable by addition of NG-monomethyl-L-arginine. These data indicate that NO induces a G1-arrest followed by apoptosis in pancreatic carcinoma cell lines.