Pancreatic Polypeptide Cell Proliferation in the Pancreas and Duodenum Coexisting in a Patient With Pancreatic Adenocarcinoma Treated With a GLP-1 Analog.

A partial pancreaticogastrodudenectomy was performed on a 66-year old man with type 2 diabetes mellitus because of an invasive, moderately differentiated adenocarcinoma in the head of the pancreas. In the adjacent grossly normal tissue of the uncinate process, there was a massive proliferation of pancreatic polypeptide (PP) cells confined to this region and showed invasive pattern. Strikingly, in the heaped area of his duodenum, there was a strikingly large number of PP, glucagon, a few insulin cells in a mini-islet-like patterns composed of glucagon and insulin cells. Among the etiological factors, the possible long-lasting effects of the GLP-1 analog, with which the patient was treated, are discussed. This is the first report in the literature of both the coexistence of a pancreatic adenocarcinoma and invasive PPoma and the occurrence of PP and insulin cells in human duodenal mucosa.

Effects of fungal pancreatic enzymes on the function of islet cells in Syrian golden hamsters.

CONTEXT: Our previous studies showed that porcine pancreatic enzymes in Syrian golden hamsters with peripheral insulin resistance normalizes the plasma insulin level, reduces the size of enlarged islets and inhibits the increased DNA synthesis in the beta-cell of islets. OBJECTIVE: In order to exclude the possibility that these effects was attributed to some contaminants of this crude material, we tested the effect of purified fungal pancreatic enzyme (FPE) that contains primarily amylase and lipase without (FPE) and with addition of chymotrypsin (FPE+chy). MATERIAL AND METHODS: In a pilot study we tested the effect of different doses of FPE given in drinking water on insulin level, islet size and DNA synthesis of islet cells in hamsters with induced peripheral insulin resistance by a high fat diet. The most effective dose of FPE on these parameters was used in a long-term experiment with FPE and FPE+chy in hamsters fed a high-fat diet for 36 or 40 weeks. RESULTS: In the pilot study a dose of 2 g/kg body weight was found to be optimal for controlling the body weight, normalizing plasma insulin level, the size of islets, the DNA synthesis and the number of insulin cells in the islets. These data were produced in the long-term study, where steatorrhea was also inhibited. Addition of chymotrypsin had no effects on these parameters. CONCLUSION: Pancreatic lipase and amylase appear to be responsible for the observed effects and offer a safe and effective natural product for the treatment of pancreatic diseases, including acute pancreatitis, chronic pancreatic, cystic fibrosis and any conditions associated with peripheral insulin resistance, including obesity and type 2 diabetes. The possible mechanism of the action is discussed.

Effects of porcine pancreatic enzymes on the pancreas of hamsters. Part 1: basic studies.

CONTEXT: Porcine pancreatic enzymes (PPE) extracted from glandular stomach has been used for the treatment of pancreatic cancer patients. Unfortunately, no information is available on the in vitro and in vivo effect on the pancreas and other tissues. OBJECTIVE: We used Syrian Golden hamsters, a unique pancreatic cancer model, to obtain basic information on PPE for its eventual use for the treatment of pancreatic cancer. DESIGN: PPE was used in different concentrations in vitro and in vivo. The stability of the enzyme in the water solution was investigated. It was given to the hamsters by gavage in concentrations of 1g/kg and 400 mg/kg for short periods and in aqueous solution for 65 days. Plasma enzyme and insulin, the size of islets and the number of the insulin cells per islet were examined. RESULTS: The enzyme activity of PPE was maintained in water solution for at least 24 hours. Due to its content of calcium chloride it showed a high toxicity to normal and malignant hamster pancreatic cancer cells and human pancreatic cancer cell lines in vitro. PPE did not alter the plasma pancreatic enzyme levels regardless of the dose, duration and application route. On the contrary, PPE reduced their levels significantly. Remarkably, it also reduced the level of insulin, the size of the islets and the number of insulin cells in the islets significantly. CONCLUSION: The results imply that PPE does not enter the blood circulation but it appears to slow down the function of both the exocrine and endocrine pancreas.

Effects of porcine pancreatic enzymes on the pancreas of hamsters. Part 2: carcinogenesis studies.

CONTEXT: Our previous study suggested that porcine pancreatic extract in hamsters with peripheral insulin resistance, normalizes insulin output, islet size and pancreatic DNA synthetic rate. It also inhibited the growth of human pancreatic cancer cells in nude mice. OBJECTIVE: To examine the potential value of the porcine pancreatic extract in controlling pancreatic carcinogenesis in this model, the present experiment was performed. DESIGN: Hamsters were fed a high fat diet and four weeks later when insulin resistance emerges, they were divided into two groups. One group received 1 g/kg BW of porcine pancreatic extract in drinking water and the other group received tap water. One week later, when insulin output normalizes in porcine pancreatic extract-treated hamsters, a single subcutaneous injection of N-nitrosobis-(2-oxopropyl) amine (BOP) at a dose of 40 mg/kg BW was given to all hamsters. The experiment was terminated at 43 weeks after the porcine pancreatic extract treatment. The number and size of pancreatic tumors, blood glucose, insulin, amylase and lipase levels, the average size of islets and the number of insulin cells/islets were determined. RESULTS: The incidence of pancreatic cancer was significantly lower in the porcine pancreatic extract group (P=0.043), as well as the plasma insulin level and the size of the islets in the porcine pancreatic extract group were significantly lower (P<0.001) than in the control group. No significantly differences were found in the glucose level between the groups. CONCLUSION: These results show that porcine pancreatic extract has a potential to inhibit pancreatic cancer growth.

A novel tissue for islet transplantation in diabetics.

BACKGROUND: Islet transplantation for diabetes therapy has remained a challenge. None of the currently used transplantation sites have provided satisfactory results as islets seem to require a specific tissue for survival and growth. Since the submandibular gland (SMG) shares physiological and anatomical similarities with the pancreas, we attempted to use this tissue as the transplantation site. METHODS: In Experiment 1, a group of 10 female Syrian Golden hamsters' (SGH) received isolated and purified homologous islets transplanted into their right SMG. In Experiment 2, 15 female SGH received islet transplant into their left SMG as above, except that the recipient hamsters were made diabetic by streptozotocin (STZ) before islet transplantation. In Experiment 3, isolated and purified human islets were transplanted into the SMG of 10 female hamsters. RESULTS: In 8 out of 10 hamsters in Experiment 1 the islets survived and showed the same morphological structure and endocrine cell content, as intrapancreatic islets and presented signs of rapid growth and distribution. Also, as in Experiment 1, well-established islets were present in Experiment 2. Ten of the 15 hamsters pretreated with STZ had blood glucose values between 96 and 125 mg/dl, whereas three hamsters remained hyperglycemic (glucose levels between 194 and 417 mg/dl). Remarkably, the islets in the pancreas of 10 STZ-treated hamsters with functioning SMG islets remained atrophic even after 12 weeks. In two hamsters transplanted islets showed degeneration and remained diabetic until their pancreatic islets regenerated. In Experiment 3, transplanted human islets were completely destroyed. CONCLUSIONS: SMG appears to be the most suitable site for islet transplantation for the treatment of diabetes.

The pattern of neural elements in the islets of normal and diseased pancreas and in isolated islets.

CONTEXT: The association between islet cells and neural elements, the so-called "neuro-insular complex", has been known for centuries. OBJECTIVE: We examined the expression of beta-III tubulin, in normal pancreases from organ donors, surgical specimens of chronic pancreatitis, surgical specimens of ductal type carcinoma, isolated and purified islets of a 57-year-old male and the pancreases of adult Syrian golden hamsters by immunohistochemistry using a monoclonal antibody to beta-tubulin. RESULTS: In the normal pancreas of humans and hamsters, beta-III tubulin was expressed in alpha- and beta-cells, but not in PP cells, neural fibers and gangliae. Occasionally, intra-and peri-insular neural elements were also found. In chronic pancreatitis and pancreatic cancer samples, the number of beta-cells and the immunoreactivity of the beta-III tubulin antibody in islet cells were decreased in most cases. In cultured human islets, devoid of neural elements, no correlation was found between the expression of beta-III tubulin and islet cell hormones. CONCLUSION: Beta-III tubulin is only expressed in the islets derived from the dorsal pancreas and in neural elements. In chronic pancreatitis and pancreatic cancer swelling of intra- and peri-insular nerves occurs, possibly in response to the loss of beta-cells. The secretion of insulin and the expression of beta-tubulin seem to be regulated by nerves.

Morphometric studies in human pancreatic cancer argues against the etiological role of type 2 diabetes in pancreatic cancer.

BACKGROUND: To understand the role of islet amyloid polypeptide (IAPP) in type 2 diabetes and pancreatic cancer (PC), we investigated the patterns of its expression and its ratio to insulin, glucagon, somatostatin and pancreatic polypeptide cells by morphometry in tissues from these two diseases in comparison to the normal pancreas. MATERIALS AND METHODS: Pancreatic tissues from 11 donors (five without pancreatic disease and six with type 2 diabetes) and 11 surgical specimens from PC patients obtained from the cancer area (zone A) and the adjacent tumor-free area (zone B) were examined immunohistochemically. The size of islets, the number on beta-, alpha-, delta- pp- and IAPP-expressing cells and their ratios in the islets of these tissues were determined. RESULTS: In the normal pancreas, only 50% of the beta-cells while alpha- and delta-cells co-expressed IAPP only sporadically. In tissues from diabetics as well as in zone A, the number of the beta-cells and the IAPP-expressing cells was reduced significantly, while the number of alpha- and delta-cells was increased. In zone B, however, significantly more beta-cell and IAPP-expressing cells and a significantly lower number of alpha-cells were found compared to those in zone A. Significant differences were also found between the specimens from type 2 diabetics and pancreatic cancer relative to the ratios of IAPP/beta-cell, IAPP/alpha-cells and beta-cell/delta-cells. CONCLUSION: The morphometric data show a decrease rather than an increase in the number of IAPP-expressing cells in PC. Differences in abnormalities in type-2 diabetics and in zone B of PC tissue strongly argue against the role of type 2 diabetes in PC. Rather, the development of diabetes in subjects prone to pancreatic cancer could be a red flag for malignancy.

Pancreatic cancer and glucose metabolism.

BACKGROUND/AIMS: The mechanism of impaired glucose metabolism that develops in most patients with pancreatic cancer is obscure. The association between pancreatic cancer and diabetes is controversial. Impaired glucose tolerance or diabetes mellitus may develop as a clinical manifestation of pancreatic cancer; however, diabetes may be a predisposing risk factor for pancreatic cancer. We aimed to investigate the relationship between diabetes and pancreatic cancer, and also the impact of tumor removal on glucose metabolism. METHODS: Eighteen pancreatic cancer patients with resectable tumors and without previous diabetes history were enrolled. All patients underwent oral glucose tolerance test and measurement of insulin levels before and after Whipple procedure. RESULTS: Eight of 18 (44.4%) patients were diabetic before surgery whereas 4 (22.2%) had impaired glucose tolerance. Only 6 (33.3%) patients had normal glucose metabolism at the first clinical admission. After pancreatectomy, only 4 (22.2%) patients were diabetic and 1 (5%) had impaired glucose tolerance. Thirteen patients (72%) had normal glucose metabolism after tumor removal. In 8 patients, impaired glucose metabolism improved after surgery. Only 1 patient out of 6 (16%) with normal glucose metabolism initially developed impaired glucose tolerance after surgery. All patients with diabetes and impaired glucose tolerance had hyperinsulinemia before and after surgery. Insulin levels were lower after surgery than before surgery, and glucose metabolism was improved postoperatively. CONCLUSIONS: Our results showed that tumor removal in pancreatic cancer patients improved glucose metabolism. This occurred despite a postoperative reduction in endocrine pancreas mass, which may suggest the presence of insulin resistance and diabetogenic effect of pancreatic cancer. The elucidation of the mechanism is of immense importance for providing an early tumor marker and preventative and therapeutic modalities.

Diabetes mellitus in pancreatic cancer: is it a causal relationship?

The relationship between type 2 diabetes mellitus and pancreatic cancer (PC) is not clear. It has been reported that the increased release of islet amyloid polypeptides (IAPPs) is responsible for the impaired glucose tolerance in PC patients. However, no information exists on the patterns of IAPP expression in PC tissue in comparison with tissue from the normal pancreas and that of a patient with type 2 diabetes. Therefore, we performed a morphometric study and compared the patterns of IAPP expression in 5 normal pancreases (as a control), 6 pancreases from patients with type 2 diabetes, and 11 surgical PC specimens, which were processed for immunohistochemistry using anti-insulin and an anti-IAPP antibody. From the cancer tissue, sections were taken from the tumor (T) and from adjacent tumor-free areas (TF). The size of islets and the number of immunostained cells in these islets were recorded. In diabetes and PC, the size of islets and the number of beta-cells was significantly lower than in the controls. Also, the number of IAPP-expressing cells was significantly lower in diabetes and in the T area but not in the TF region. In addition, no characteristic changes found in diabetic pancreases were observed in the TF area, indicating that PC patients had no prior diabetic diseases. The reduction in the number of IAPP in the T area seems to argue against the role of IAPP in glucose abnormality in PC patients. The primary endocrine alteration in the tumor area suggests that cancer cells produce diabetogenic substances, the nature of which awaits further research.

Distribution of pancreatic endocrine cells including IAPP-expressing cells in non-diabetic and type 2 diabetic cases.

There is a lack of agreement on the distribution of islet amyloid polypeptide (IAPP) in the pancreases of healthy and diabetic subjects. Therefore, a detailed morphometrical and immunohistochemical study was performed to obtain information on the distribution of cells expressing insulin, glucagon, somatostatin, pancreatic polypeptide (PP), and IAPP in the pancreases of non-diabetic (n=4) and diabetic individuals (n=6). In the non-diabetic cases, beta-cells contributed to approximately 64%, alpha-cells to 26%, delta-cells to 8%, PP cells to 0.3%, and IAPP cells to 34% of the islet cell population. The ratio of IAPP/insulin was approximately 1:2. In diabetic cases, beta-cells were decreased by 24%, and IAPP was decreased by 57%. The alpha- and delta-cells were increased by 40% and 58%, respectively. IAPP/insulin ratio was decreased by 41%. Thus, only 50% of the beta-cells in non-diabetics and only 30% in diabetics coexpressed IAPP. In diabetics, more delta-cells coexpressed IAPP than in non-diabetics. The results seem to argue against the notion that the secretion of IAPP is increased in diabetics. It is possible that an increase in somatostatin and glucagon plays a greater role in diabetes than IAPP.

MUC4-expressing pancreatic adenocarcinomas show elevated levels of both T1 and T2 cytokines: potential pathobiologic implications.

OBJECTIVE: The human MUC4 mucin plays an important role in the pathogenesis of pancreatic cancer. Recently, we have demonstrated that MUC4 expression in pancreatic tumor cells is regulated by interferon-gamma (IFNgamma) and by retinoic acid via transforming growth factor beta 2 (TGFbeta-2). In the present study, we established the pathobiological association of various cytokines and MUC4 in pancreatic tumor tissues and tumor cell lines. METHODS: Using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and/or immunohistochemical analyses, we examined the expression of MUC4, IFNgamma, TGFbetas, and several immunologically relevant cytokines in a panel of 11 pancreatic adenocarcinomas (PA), three normal pancreatic (NP) tissue specimens, and 11 pancreatic tumor cell lines. RESULTS: Our data revealed that both MUC4 and IFNgamma were expressed at moderate to high levels in the majority of PA, while being undetectable in NP. Moreover, transcript for interleukin 2 (IL-2), a known marker of activated T helper 1 (TH1) lymphocytes, exhibited an expression profile similar to IFNgamma, suggesting a role of these immune effector cells as a potential source of IFNgamma in PA. Of note, IFNgamma protein was detected in the inflamed tissues neighboring tumor areas. Furthermore, TGFbetas were expressed by most cell lines and frequently upregulated in PA compared with NP. Interestingly, both IL-12 and IL-10, two key cytokines of the TH1 and TH2 pathways, respectively, were expressed at higher levels in PA relative to NP. CONCLUSIONS: These observations support the potential implication of IFNgamma and TGFbetas in MUC4 regulation in vivo and suggest a complex interaction of TH1 and TH2 signaling in the pancreatic tumor microenvironment. These findings may provide useful insights into the pathobiology of pancreatic cancer.

Expression of Oct4, a stem cell marker, in the hamster pancreatic cancer model.

BACKGROUND: Oct4 has been shown to present a stem cell marker that is expressed in embryonic cells and in germ cell tumors. Recently, its expression in a few human tissues and cancer cells has been reported. Because in the hamster pancreatic cancer model most tumors develop from within islets presumably from stem cells, we investigated the expression of Oct4 in this model. METHODS: Two normal pancreases and 15 pancreatic cancers induced by N-nitrosobis(2-oxypropyl)amine (BOP) were processed for immunohistochemistry using a monoclonal Oct4 antibody at a concentration of 1:500. RESULTS: In the normal pancreas, Oct4 was expressed only in islet cells in a diffuse cytoplasmic pattern. No nuclear staining was found in any cells. In 14 of the pancreatic cancers, nuclear staining was detected in many cells or in small foci. Diffuse cytoplasmic but no nuclear staining was found in one tumor and a mixed Golgi type and nuclear staining in two cases. Nuclear staining was also identified in early intrainsular ductular and in Ca in situ lesions. CONCLUSIONS: BOP reactivates the Oct4 gene and can be considered an early tumor marker in this model.

Are there any stem cells in the pancreas?

A vast number of studies indicate the presence of stem/progenitor cells virtually in all tissues in adult organs, particularly in bone marrow. Recent studies, however, cast doubt about the existence of true stem cells in adult tissue. The complex integrity of several cells with distinct morphologic and functional properties in the mature pancreas confers an appropriate status for stem cell research. Several different types of cells residing in the islets or in the ductal epithelium have been proposed as adult pancreatic stem cells or progenitor cells. However, these reports do not provide conceivable proof for the presence of true pancreatic stem cells. On the other hand, there is considerable evidence indicating transdifferentiation of all adult pancreatic cells into each other, and under proper conditions, to nonpancreatic cells including oncocytes and hepatocytes. Observations pertaining to the putative pancreatic stem cells, transdifferentiation ability of the differentiated mature pancreatic cells in the normal and diseased pancreas will be discussed, and our own findings supporting the transdifferentiation pathway are presented in this article.

High concentrations of retinoids induce differentiation and late apoptosis in pancreatic cancer cells in vitro.

BACKGROUND: Our previous investigations showed that retinoids, at specific concentrations, can inhibit cell proliferation. In this investigation, we hypothesize that high concentrations of retinoids can induce phenotypic changes (differentiation) and late apoptosis in pancreatic cancer cells in vitro. MATERIALS AND METHODS: To test our hypothesis, retinoid-induced differentiation was assessed: (1) phenotypically by light and electron microscopy and (2) biochemically by measuring carbonic anhydrase, aerobic metabolic and mucin producing activities. Modulation of transforming growth factor-beta (TGF-beta) and epidermal growth factor (EGF) autocrine pathways were utilized as mechanistic and differentiation markers. RESULTS: The extensive differentiation-indicative phenotypic changes correlated with several folds increase in the aerobic metabolism (MTT reduction and Mitochondrial mass), carbonic anhydrase activity and mucin production. There was a marked increase in TGF-beta (Bioassay and ELISA) and TGF-beta (RIA) secretion. EGF receptor density (Receptor binding assay) was reduced by 50% within six hours and was reflected on abolishment of EGFR ligand-induced proliferation. Cotreatment with the RAR-alpha antagonist, Ro41-5253 or pan-TGF-beta neutralizing antibody abolished the phenotypic and antiproliferative effects of all-trans retinoic acid. Apoptosis (TUNEL assay) was undetectable after three days of treatment with the maximum concentration used. However, apoptosis was extensively induced after six days of treatment. CONCLUSIONS: High concentrations of retinoids were able to induce phenotypic changes (differentiation) and late apoptosis in pancreatic cancer cells in vitro. The clinical ramifications of these observations await further investigations.

Pancreatic hepatocellular tumor.

BACKGROUND: Hepatocellular differentiation of pancreatic cells has been observed under certain conditions in several species, including humans. Their cell of origin and biology has remained controversial. Generally, these lesions have been considered a degenerative process. The present study describes a neoplastic hepatocellular lesion in Syrian hamsters. METHODS AND RESULTS: Syrian hamsters were treated with a high dose of pancreatic carcinogen, N-nitrosobis(2-oxopropyl)amine. The lesion was confined within a single islet and expressed albumin and HSA (hepatocyte-specific antigen). The pleomorphic tumor cells exhibited numerous mitotic figures and were intermingled with insulin and glucagon cells. The hamster had multicentric premalignant and malignant ductal-type lesions, most of which appeared to arise from within the islets. This is the first demonstration of pancreatic hepatoma. CONCLUSION: Pancreatic islet cells appear to have the potential to transdifferentiate into neoplastic hepatocytes.

Natural retinoids inhibit proliferation and induce apoptosis in pancreatic cancer cells previously reported to be retinoid resistant.

BACKGROUND: The anticancer ability of natural retinoids on pancreatic adenocarcinoma, an aggressive tumor, is still controversial. This investigation tested the hypothesis that all-trans retinoic acid can inhibit proliferation and induce apoptosis in pancreatic cancer cell lines. MATERIALS AND METHODS: Using our previously optimized conditions, the effect of all-trans retinoic acid (atRA, 0.001-10 microM) was tested in ten human pancreatic adenocarcinoma cell lines with various degrees of differentiation. Proliferation was monitored by cell number, [3H]-thymidine incorporation and cell cycle arrest. Apoptosis was investigated morphologically by light and electron microscopy and biochemically by tissue transglutaminase activity (TGase), mitochondrial membrane potential, cell cycle analysis of sub-G1 cells and detection of fragmented DNA (fragmentation of prelabeled DNA, agarose electrophoresis and TUNEL assays). RESULTS: Retinoic acid caused potent concentration- and time-dependent inhibition of proliferation of all cell lines studied. Cell cycle was arrested at G1 or G2 with extensive reduction of number of cells at S-phase after 24 hours of treatment with apoptotic concentration of atRA. Complete inhibition of proliferation was followed by apoptosis as indicated by the progressive accumulation of sub-G1 apoptotic cells which was confirmed by the more specific DNA fragmentation assays. There were extensive apoptosis-indicative light and electron microscopic changes preceded by phenotypic redifferentiation. TGase was induced between 3-5-fold the control level and its inhibition partially reversed the antiproliferative effect of atRA. Cellular viability during the preapoptotic stage was confirmed by normal mitochondrial membrane potential in the first two days of treatment with the maximum atRA concentration used. However, the potential was progressively reduced with time as a preapoptotic change. Caspase 3-like activity was induced by the apoptotic concentrations of atRA at late time points. However, the redifferentiation indicative changes were not prevented by cotreatment with Ac-DEVE-CHO caspase 3 inhibitor. CONCLUSIONS: Together, our results demonstrated the efficient anticancer ability of natural retinoids on human pancreatic cancer cell lines tested, even those previously reported to be retinoid resistant.

ErbB2 growth factor receptor, a marker for neuroendocrine cells?

BACKGROUND/AIMS: The overexpression of ErbB2 in pancreatic cancer has been reported with a varying incidence ranging between 1 and 80%. Our routine examination, however, revealed a consistently strong immunoreactivity of three anti-ErbB2 growth factor receptor antibodies in pancreatic islets and intrapancreatic ganglia. To validate our findings and to understand the reasons for the reported differences in the frequency of ErbB2 overexpression in pancreatic cancer, the following studies were performed. MATERIALS AND METHODS: Tissue samples from 12 normal pancreata, 7 surgical chronic pancreatitis cases, 21 primary pancreatic adenocarcinomas, 9 metastatic pancreatic adenocarcinomas, and 4 islet cell tumors were subjected to immunohistochemical examination using antibodies from three manufacturers. Cultured human islet cells and pancreatic cancer cell lines, as well as samples from the gastrointestinal tract, the CNS, and the adrenal gland were included in the study. For comparison, mammary cancer tissue and mammary cancer cells, as well as selected tissues from Syrian golden hamsters, were used. To verify the results, Western blot and Northern slot-blot analyses were performed. RESULTS: Pancreatic cancer cells, in vitro and in vivo, showed a remarkable heterogeneity in the immunostaining of ErbB2, ranging from very faintly to strongly stained. On the other hand, in both humans and hamsters, a consistently strong immunostaining was found in the Langerhans' islets, in the ganglia of intrapancreatic and extrapancreatic nerves, as well as in the CNS, spinal cord and adrenal gland. CONCLUSIONS: ErbB2 appears to play an important role in neuroendocrine tissues and is probably involved in the development and functional regulation of these cells. The concomitant expression of these factors and islet cell hormones very likely results in the activation of multiple growth-promoting pathways in pancreatic cancer and its aggressive behavior.

ErbB2 oncogene antibodies differentiate between the normal and diseased pancreas, and between chronic pancreatitis and pancreatic cancer.

Histological differentiation between chronic pancreatitis and pancreatic cancer, especially in biopsy material, remains challenging and the frequent association of 'secondary' chronic pancreatitis (due to ductal obstruction) with pancreatic cancer causes additional diagnostic problems. Our study, using anti-ErbB2 antibodies from Santa Cruz and Dako in tissues from the normal pancreas, chronic pancreatitis and pancreatic cancer showed that these antibodies discriminate between primary chronic pancreatitis and 'secondary' chronic pancreatitis due to pancreatic cancer. Tissues from 28 pancreatic cancer patients, 15 chronic pancreatitis patients and 12 organ donors or early autopsy cases were subjected to immunohistochemical studies using polyclonal ErbB2 antibodies from Santa Cruz and Dako. The Santa Cruz antibody immunoreacted with islet cells in all tissues from the normal pancreas and pancreatic cancer but not in any chronic pancreatitis specimen. The Dako antibody showed a membrane staining of ductal and ductular cells only in chronic pancreatitis cases but in none of the normal or cancer specimens. Moreover, in chronic pancreatitis cases, ductular cells were stained with the Santa Cruz antibody only in the severe form, but not in the mild or moderate form of the disease. The utilized ErbB2 antibodies discriminate between the normal pancreas, chronic pancreatitis and pancreatic cancer. Hence, these antibodies seem to present an additional useful aid in the surgical pathology of pancreatic diseases.

The combination of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) and Genistein is effective in inhibiting pancreatic cancer growth.

OBJECTIVES: Our previous studies have shown that, contrary to many other human pancreatic adenocarcinoma cell lines, AsPC1 cells are resistant to the apoptotic effect of the tumor necrosis factor-related apoptosis-inducing ligand, also called Apo2L (TRAIL/Apo2L). In our in vitro studies, the combination of TRAIL/Apo2L and protein synthesis inhibitor, genistein, but not genistein alone, was, however, effective in inducing apoptosis in AsPC1 cells. In the present study, we examined the effect of TRAIL/Apo2L with genistein on the growth of AsPC1 cells in vitro and in vivo. METHODS: Mice with orthotopically transplanted AsPC1 cells were treated either with TRAIL/Apo2L, Genistein (Gen) or a combination of both (TRAIL/Apo2L + Gen) for 14 days. After 14 days, the size and weight of the tumors were registered and the apoptosis of the tumor cells were determined by the TUNEL method. In vitro, the effect of combination treatment on cytotoxicity was assessed by MTT assay and apoptosis was assessed by DAPI staining. FADD, caspase 3, and PARP proteins were determined by Western blot. RESULTS: No toxic side effects were observed in either group. The tumor volume was significantly smaller and the apoptotic ratio was higher in the TRAIL + Gen group than in the other 2 groups. The apoptotic effect was associated with the caspase-3 activation. Z-VAD-FMK partially inhibited apoptosis by TRAIL + Gen. CONCLUSIONS: These results indicate that the combination of TRAIL/Apo2L with genistein presents a promising therapeutic approach for the treatment of pancreatic cancer. Further detail investigations are needed, however, to verify the mechanisms of this combination therapy.

Pancreatic enzyme extract improves survival in murine pancreatic cancer.

OBJECTIVES: The disappointing current therapeutic approaches for pancreatic cancer (PC) represent an urgent need for the development of novel methods to control the disease. Based on a recent report on the effectiveness of pancreatic enzyme therapy, we examined the effect of porcine pancreatic enzyme extracts (PPE) on human PC xenografts in nude mice. METHODS: The malignant human PC cell line AsPC1 was transplanted into the pancreas of male beige XID nude mice that were treated or not with PPE in drinking water. The survival, size, and volume of tumors, plasma pancreatic enzyme levels, fecal fat, and urine were examined as were the expression of transforming growth factor alpha, insulinlike growth factor-I, epidermal growth factor, epidermal growth factor receptor, apoptosis, and proliferation rate of tumor cells. RESULTS: PPE-treated mice survived significantly longer than the control group (P < 0.002). Tumors in the PPE-treated group were significantly smaller than in the control group. All mice in the control group showed steatorrhea, hyperglucosuria, hyperbilirubinuria, and ketonuria at early stages of tumor growth, whereas only a few in the treated group showed some of these abnormalities at the final stage. There were no differences in the expression of growth factors, epidermal growth factor receptor, or the apoptotic rate between the tumors of treated and control mice. CONCLUSIONS: The treatment with PPE significantly prolongs the survival of mice with human PC xenografts and slows the tumor growth. The data indicate that the beneficial effect of PPE on survival is primarily related to the nutritional advantage of the treated mice.