Hereditary pancreatitis and pancreatic carcinoma

Exploring the role of TLK2 mutation in tropical calcific pancreatitis: an in silico and molecular dynamics simulation study

Tropical calcific pancreatitis (TCP) is a juvenile form of non-alcoholic chronic pancreatitis seen exclusively in tropical countries. The disease poses a high risk of complications, including pancreatic diabetes and cancer, leading to significant mortality due to poor diagnosis and ineffective treatments. This study employed whole exome sequencing (WES) of 5 TCP patient samples to identify genetic variants associated with TCP. Advanced computational techniques were used to gain atomic-level insights into disease progression, including microsecond-scale long MD simulations and essential dynamics. In silico virtual screening was performed to identify potential therapeutic compounds targeting the mutant protein using the Asinex and DrugBank compound library. WES analysis predicted several single nucleotide variants (SNVs) associated with TCP, including a novel missense variant (c.T1802A or p.V601E) in the TLK2 gene. Computational analysis revealed that the p.V601E mutation significantly affected the structure of the TLK2 kinase domain and its conformational dynamics, altering the interaction profile between ATP and the binding pocket. These changes could impact TLK2's kinase activity and functions, potentially correlating with TCP progression. Promising lead compounds that selectively bind to the TLK2 mutant protein were identified, offering potential for therapeutic interventions in TCP. These findings hold great potential for future research.Communicated by Ramaswamy H. Sarma.

Pancreatic Cancer Exposome Profile to Aid Early Detection and Inform Prevention Strategies

Pancreatic cancer (PCa) is associated with a poor prognosis and high mortality rate. The causes of PCa are not fully elucidated yet, although certain exposome factors have been identified. The exposome is defined as the sum of all environmental factors influencing the occurrence of a disease during a life span. The development of an exposome approach for PCa has the potential to discover new disease-associated factors to better understand the carcinogenesis of PCa and help with early detection strategies. Our systematic review of the literature identified several exposome factors that have been associated with PCa alone and in combination with other exposures. A potential inflammatory signature has been observed among the interaction of several exposures (i.e., smoking, alcohol consumption, diabetes mellitus, obesity, and inflammatory markers) that further increases the incidence and progression of PCa. A large number of exposures have been identified such as genetic, hormonal, microorganism infections and immune responses that warrant further investigation. Future early detection strategies should utilize this information to assess individuals' risk for PCa.

Familial pancreatic cancer: who should be considered for genetic testing?

BACKGROUND

Determining how many female patients who underwent breast imaging meet the eligibility criteria for genetic testing for familial pancreatic cancer (FPC).

METHODS

A total of 42,904 patients seen at the Newton-Wellesley Hospital between 2007 and 2009 were retrospectively reviewed. The first four categories were based on pancreatic cancer-associated syndromes: (1) hereditary breast and ovarian cancer (HBOC), (2) Lynch syndrome (LS), (3) familial atypical multiple mole melanoma (FAMMM), and (4) family history of FPC (FH-FPC). PancPRO (5) and MelaPRO (6) categories were based on risk scores from Mendelian risk prediction tool.

RESULTS

Exactly 4445 of 42,904 patients were found to be in at least one of the six risk categories. About 5.7% of patients were classified as being at high risk for HBOC, 2.3% as being at high risk for LS, 0.1% as being at high risk for FAMMM, 0.1% as being at high risk for FH-FPC, 2.7% as being at high risk based on PancPRO, and 0.2% as being at high risk based on MelaPRO.

CONCLUSION

About 10.4% of the female patients were classified as being at high risk for FPC. This finding emphasizes the importance of applying criteria to the general population, in order to ensure that individuals with high risk are identified early.

Acute recurrent and chronic pancreatitis in children

Acute recurrent pancreatitis (ARP) is defined as two distinct episodes of acute pancreatitis (AP), whereas chronic pancreatitis (CP) is caused by persistent inflammation of the pancreas. In children they are caused by genetic mutations, autoimmune pancreatitis, congenital pancreatic abnormalities, and other conditions. Acute recurrent pancreatitis is frequently a precursor to CP, and both are thought to be on the same disease continuum. In particular, genetic factors are associated with early progression of ARP to CP. The diagnosis of CP, as in AP, is based on clinical findings, biochemical tests, and imaging studies. Findings of exocrine pancreatic dysfunction are also important in the diagnosis of CP. A step-up strategy has become increasingly standard for the treatment of patients with CP. This strategy starts with endoscopic treatment, such as pancreatic sphincterotomy and stenting, and progresses to surgery should endoscopic therapy fail or prove technically impossible. Non-opioid (e.g. ibuprofen / naproxen) and opioid (e.g. oxycodone) forms of analgesia are widely used in pediatric patients with AP or CP, whereas pancreatic enzyme replacement therapy may be beneficial for patients with abdominal pain, steatorrhea, and malnutrition. Despite the disparity in the age of onset, pediatric CP patients display some similarities to adults in terms of disease progress. To reduce the risk of developing pancreatic exocrine inefficiency, diabetes and pancreatic cancer in the future, clinicians need to be aware of the current diagnostic approach and treatment methods for ARP and CP and refer them to a pediatric gastroenterologist in a timely manner.

Familial Pancreatic Cancer and Surveillance of High-Risk Individuals

Family history of pancreatic cancer (PC) is a risk factor for PC development, and the risk level correlates with the number of affected families. A case of PC with ≥1 PC cases in the first-degree relative is broadly defined as familial pancreatic cancer (FPC) and accounts for 5% to 10% of total PC cases. FPC possesses several epidemiological, genetic and clinicopathological aspects that are distinct from those of conventional PCs. In Western countries, FPC registries have been established since the 1990s, and high-risk individuals are screened to detect early PCs. For the pharmacotherapy of FPC, especially in cases with germline pathogenic BRCA mutations, regimens using platinum and poly (ADP-ribose) polymerase inhibitor have recently been studied for their effectiveness. To date, the concept of FPC has prevailed in Western countries, and it has begun to infiltrate into Eastern countries. As the genetic background and environmental conditions vary in association with ethnicity and living area, we need to establish our own FPC registries and accumulate data in Asian countries.

Surveillance of Individuals with a Family History of Pancreatic Cancer and Inherited Cancer Syndromes: A Strategy for Detecting Early Pancreatic Cancers

A family history of pancreatic cancer (PC) is a risk factor of PC, and risk levels increase as affected families grow in number and/or develop PC at younger ages. Familial pancreatic cancer (FPC) is defined as a client having at least two PC cases in a first degree relatives. In the narrow sense, FPC does not include some inherited cancer syndromes that are known to increase the risks of PC, such as Peutz-Jeghers syndrome (PJS), hereditary pancreatitis (HP), hereditary breast ovarian cancer syndrome (HBOC), and so on. FPC accounts for 5%-10% of total PC diagnoses and is marked by several features in genetic, epidemiological, and clinicopathological findings that are similar to or distinct from conventional PC. Recent advances in genetic medicine have led to an increased ability to identify germline variants of cancer-associated genes. To date, high-risk individuals (HRIs) in many developed countries, including FPC kindreds and inherited cancer syndromes, are screened clinically to detect and treat early-stage PC. This article highlights the concept of FPC and the most recent data on its detection.

NO• and Pancreatic Cancer: A Complex Interaction with Therapeutic Potential

SIGNIFICANCE

Pancreatic tumors express high level of nitric oxide synthases (NOSs) in particular inducible (iNOS/NOS2) and endothelial (eNOS/NOS3) forms. However, the role of nitric oxide (NO^•) in the development and progression of pancreatic cancer is not clearly defined. Delineating the NO^•-induced signaling in pancreatic cancer and its potential contribution in disease aggressiveness may provide therapeutic targets to improve survival in this lethal malignancy. Recent Advances: An increased expression of NOS2/iNOS in tumors is associated with poorer survival in early stage resected patients with pancreatic ductal adenocarcinoma (PDAC). Furthermore, genetic deletion of NOS2 enhanced survival in mice with autochthonous PDAC. Additionally, targeting NOS3/eNOS reduced the abundance of precursor lesions in mice, which trended toward improved survival.

CRITICAL ISSUES

The extremely poor prognosis in pancreatic cancer is due to the late diagnosis and lack of effective therapy in advanced disease. One of the most critical issues is to decipher the underlying mechanism of disease aggressiveness and therapeutic resistance for identifying potential therapeutic target and effective treatment. Given the evidence of a strong association between inflammation and pancreatic cancer and clinical evidence, which suggests an association between NOS2 and disease aggressiveness, it is critical to define the role of NO^• signaling in this lethal malignancy.

FUTURE DIRECTIONS

Recent preclinical and clinical evidences indicate a potential therapeutic significance of targeting NO^• signaling in pancreatic cancer. With the emergence of new preclinical models, including the patient-derived organoids, further preclinical evaluation using clinically tested NOS inhibitors is needed for designing future clinical investigation. Antioxid. Redox Signal. 26, 1000-1008.

Specific Radiological Imaging Findings in Patients With Hereditary Pancreatitis During a Long Follow-up of Disease

OBJECTIVES

Hereditary pancreatitis (HP) is characterized by recurrent episodes of inflammation of the pancreas. Radiological imaging is used to diagnose HP and to monitor complications. The aim of this study was to describe specific imaging findings in HP.

METHODS

We retrospectively collected data of HP patients with serial imaging and reviewed all radiological imaging studies (transabdominal ultrasonography, computed tomography, and magnetic resonance imaging).

RESULTS

We included 15 HP patients, with a mean age of 32.5 years (range, 9-61 years) and mean disease duration of 24.1 years (range, 6-42 years). In total, 152 imaging studies were reviewed. Seventy-three percent of patients had a dilated main pancreatic duct (MPD) (width 3.5-18 mm). The MPD varied in size during disease course, with temporary reduction in diameter after drainage procedures. A severe dilated MPD (>10 mm) often coincided with presence of intraductal calcifications (size, 1-12 mm). In 73% of patients, pancreatic parenchyma atrophy occurred, which did not correlate with presence of exocrine or endocrine insufficiency.

CONCLUSIONS

In HP, the MPD diameter increases with time, mostly without dilated side branches, and is often accompanied by large intraductal calcifications. The size of the MPD is independent of disease state. Atrophy of pancreatic parenchyma is not correlated with exocrine or endocrine insufficiency.

Genetic Analysis of Japanese Children With Acute Recurrent and Chronic Pancreatitis

OBJECTIVES

Causes of acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP) are sometimes difficult to determine in children. In such patients, genetic analysis may prove helpful. The present study analyzed mutations of cationic trypsinogen (PRSS1), serine protease inhibitor Kazal type 1 (SPINK1), chymotrypsin C (CTRC), and carboxypeptidase A1 (CPA1) and investigated the clinical features of children with these mutations.

METHODS

Genetic analyses of mutations in these 4 genes were conducted in 128 patients with ARP or CP. Characteristics of the patients showing mutations were investigated using medical records.

RESULTS

Fifty of the 128 (39.1%) subjects had at least 1 mutation (median age at onset, 7.6 years). Abdominal pain was the presenting symptom of pancreatitis in 48 of the 50 patients (96%). Fifteen of those 50 patients (30.0%) had a family history of pancreatitis. Gene mutations were present in PRSS1 in 26 patients, SPINK1 in 23, CTRC in 3, and CPA1 in 5. In the 31 patients with mutations in SPINK1, CTRC, or CPA1, 16 (51.6%) had homozygous or heterozygous mutations with other mutations. Three patients underwent surgery and another 4 patients underwent endoscopy to manage ARP or CP. Although 3 of the 7 patients complained of mild abdominal pain, none of those 7 patients experienced any obvious episode of ARP after treatment.

CONCLUSIONS

In pediatric patients with idiopathic ARP and CP, genetic analysis is useful for identifying the cause of pancreatitis. Early endoscopic or surgical treatment prevents ARP by extending the interval between episodes of pancreatitis in this population.

Environmental risk factors for pancreatic cancer: an update

Pancreatic cancer (PC) is one of the most aggressive diseases. Only 10 % of all PC cases are thought to be due to genetic factors. Here, we analyzed the most recently published case-control association studies, meta-analyses, and cohort studies with the aim to summarize the main environmental factors that could have a role in PC. Among the most dangerous agents involved in the initiation phase, there are the inhalation of cigarette smoke, and the exposure to mutagenic nitrosamines, organ-chlorinated compounds, heavy metals, and ionizing radiations. Moreover, pancreatitis, high doses of alcohol drinking, the body microbial infections, obesity, diabetes, gallstones and/or cholecystectomy, and the accumulation of asbestos fibers seem to play a crucial role in the progression of the disease. However, some of these agents act both as initiators and promoters in pancreatic acinar cells. Protective agents include dietary flavonoids, marine omega-3, vitamin D, fruit, vegetables, and the habit of regular physical activity. The identification of the factors involved in PC initiation and progression could be of help in establishing novel therapeutic approaches by targeting the molecular signaling pathways responsive to these stimuli. Moreover, the identification of these factors could facilitate the development of strategies for an early diagnosis or measures of risk reduction for high-risk people.

High risk factors of pancreatic carcinoma

Over the past decades, cancer has become one of the toughest challenges for health professionals. The epidemiologists are increasingly directing their research efforts on various malignant tumor worldwide. Of note, incidence of cancers is on the rise more quickly in developed countries. Indeed, great endeavors have to be made in the control of the life-threatening disease. As we know it, pancreatic cancer (PC) is a malignant disease with the worst prognosis. While little is known about the etiology of the PC and measures to prevent the condition, so far, a number of risk factors have been identified. Genetic factors, pre-malignant lesions, predisposing diseases and exogenous factors have been found to be linked to PC. Genetic susceptibility was observed in 10% of PC cases, including inherited PC syndromes and familial PC. However, in the remaining 90%, their PC might be caused by genetic factors in combination with environmental factors. Nonetheless, the exact mechanism of the two kinds of factors, endogenous and exogenous, working together to cause PC remains poorly understood. The fact that most pancreatic neoplasms are diagnosed at an incurable stage of the disease highlights the need to identify risk factors and to understand their contribution to carcinogenesis. This article reviews the high risk factors contributing to the development of PC, to provide information for clinicians and epidemiologists.

Ablation of sensory neurons in a genetic model of pancreatic ductal adenocarcinoma slows initiation and progression of cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an exuberant inflammatory desmoplastic response. The PDAC microenvironment is complex, containing both pro- and antitumorigenic elements, and remains to be fully characterized. Here, we show that sensory neurons, an under-studied cohort of the pancreas tumor stroma, play a significant role in the initiation and progression of the early stages of PDAC. Using a well-established autochthonous model of PDAC (PKC), we show that inflammation and neuronal damage in the peripheral and central nervous system (CNS) occurs as early as the pancreatic intraepithelial neoplasia (PanIN) 2 stage. Also at the PanIN2 stage, pancreas acinar-derived cells frequently invade along sensory neurons into the spinal cord and migrate caudally to the lower thoracic and upper lumbar regions. Sensory neuron ablation by neonatal capsaicin injection prevented perineural invasion (PNI), astrocyte activation, and neuronal damage, suggesting that sensory neurons convey inflammatory signals from Kras-induced pancreatic neoplasia to the CNS. Neuron ablation in PKC mice also significantly delayed PanIN formation and ultimately prolonged survival compared with vehicle-treated controls (median survival, 7.8 vs. 4.5 mo; P = 0.001). These data establish a reciprocal signaling loop between the pancreas and nervous system, including the CNS, that supports inflammation associated with oncogenic Kras-induced neoplasia. Thus, pancreatic sensory neurons comprise an important stromal cell population that supports the initiation and progression of PDAC and may represent a potential target for prevention in high-risk populations.

Macrophage migration inhibitory factor induces epithelial to mesenchymal transition, enhances tumor aggressiveness and predicts clinical outcome in resected pancreatic ductal adenocarcinoma

MIF is a proinflammatory cytokine and is implicated in cancer. A higher MIF level is found in many human cancer and cancer-prone inflammatory diseases, including chronic pancreatitis and pancreatic cancer. We tested the hypothesis that MIF contributes to pancreatic cancer aggressiveness and predicts disease outcome in resected cases. Consistent with our hypothesis we found that an elevated MIF mRNA expression in tumors was significantly associated with poor outcome in resected cases. Multivariate Cox-regression analysis further showed that MIF is independently associated with patients' survival (HR = 2.26, 95% CI = 1.17-4.37, p = 0.015). Mechanistic analyses revealed that MIF overexpression decreased E-cadherin and increased vimentin mRNA and protein levels in pancreatic cancer cell lines, consistent with the features of epithelial-to-mesenchymal transition (EMT). Furthermore, MIF-overexpression significantly increased ZEB1/2 and decreased miR-200b expression, while shRNA-mediated inhibition of MIF increased E-cadherin and miR-200b expression, and reduced the expression of ZEB1/2 in Panc1 cells. Re-expression of miR-200b in MIF overexpressing cells restored the epithelial characteristics, as indicated by an increase in E-cadherin and decrease in ZEB1/2 and vimentin expression. A reduced sensitivity to the chemotherapeutic drug, gemcitabine, occurred in MIF-overexpressing cells. Indicative of an increased malignant potential, MIF over-expressing cells showed significant increase in their invasion ability in vitro, and tumor growth and metastasis in an orthotopic xenograft mouse model. These results support a role of MIF in disease aggressiveness, indicating its potential usefulness as a candidate target for designing improved treatment in pancreatic cancer.

Ablation of 5-lipoxygenase mitigates pancreatic lesion development

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), which continues to have a dismal prognosis, is associated with a pronounced fibroinflammatory response. Inflammation in vivo can be mediated by 5-lipoxygenase (5LO), an enzyme that converts omega-6 fatty acids (FA) to eicosanoids, including leukotriene B4 (LTB4). We have previously shown that diets rich in omega-6 FA increase pancreatic lesions and mast cell infiltration in EL-Kras mice. In this study, we evaluated the role of 5LO in generating higher levels of LTB4 from human cells and in mediating lesion development and mast cell infiltration in EL-Kras mice.

MATERIALS AND METHODS

Human pancreatic ductal epithelial and cancer cells were treated with omega-6 FA in vitro. EL-Kras mice lacking 5LO (EL-Kras/5LO(-/-)) mice were generated and fed standard chow or omega-6 FA diets. Pancreatic lesion frequency and mast cell infiltration were compared with EL-Kras/5LO(+/+) mice. Human PDAC tumors were evaluated for 5LO expression and mast cells.

RESULTS

Human pancreatic ductal epithelial and pancreatic cancer cells treated with omega-6 FA generated increased LTB4 levels in vitro. EL-Kras/5LO(-/-) mice developed fewer pancreatic lesions and had decreased mast cell infiltration when compared with EL-Kras/5LO(+/+) mice. Human PDAC tumors with increased 5LO expression demonstrate increased mast cell infiltration. Additionally, diets rich in omega-6 FA failed to increase pancreatic lesion development and mast cell infiltration in EL-Kras/5LO(-/-) mice.

CONCLUSIONS

The expansion of mutant Kras-induced lesions via omega-6 FA is dependent on 5LO, and 5LO functions downstream of mutant Kras to mediate inflammation, suggesting that 5LO may be a potential chemopreventive and therapeutic target in pancreatic cancer.

The histopathology of PRSS1 hereditary pancreatitis

Hereditary pancreatitis is an autosomal dominant disorder with 80% penetrance and variable expressivity. The vast majority of cases have been linked to mutations within the cationic trypsinogen gene, also referred to as serine protease 1 (PRSS1). Other than inheritance, PRSS1 pancreatitis has been considered clinically and pathologically indistinguishable from other etiologies of chronic pancreatitis. However, to date, the histologic findings of PRSS1 pancreatitis have not been well described. We, therefore, collected pancreatic specimens from 10 PRSS1 patients of various ages and examined their clinicopathologic features. Patients at the time of resection ranged in age from 9 to 66 years (median, 29 y), with a slight female predominance (60%). All patients reported a history of intermittent abdominal pain, with an age of onset ranging from infancy to 21 years of age. Examination of the gross and microscopic findings suggested a sequential pattern of changes with increasing patient age. In pediatric patients (n=4), although in most cases the pancreas was grossly normal, there was microscopic variation in lobular size and shape. Although the central portions of the pancreas displayed parenchymal loss accompanied by loose perilobular and interlobular fibrosis, the periphery was remarkable for replacement by mature adipose tissue. These changes were more developed in younger adults (n=2), in whom fatty replacement seemed to extend from the periphery to the central portions of the pancreas. With older patients (n=4), the pancreas showed marked atrophy and extensive replacement by mature adipose tissue with scattered islets of Langerhans and rare acinar epithelium concentrated near the main pancreatic duct. In summary, PRSS1 hereditary pancreatitis is characterized by progressive lipomatous atrophy of the pancreas.

Involvement of inflammatory factors in pancreatic carcinogenesis and preventive effects of anti-inflammatory agents

Chronic inflammation is known to be a risk for many cancers, including pancreatic cancer. Heavy alcohol drinking and cigarette smoking are major causes of pancreatitis, and epidemiological studies have shown that smoking and chronic pancreatitis are risk factors for pancreatic cancer. Meanwhile, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are elevated in pancreatitis and pancreatic cancer tissues in humans and in animal models. Selective inhibitors of iNOS and COX-2 suppress pancreatic cancer development in a chemical carcinogenesis model of hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). In addition, hyperlipidemia, obesity, and type II diabetes are also suggested to be associated with chronic inflammation in the pancreas and involved in pancreatic cancer development. We have shown that a high-fat diet increased pancreatic cancer development in BOP-treated hamsters, along with aggravation of hyperlipidemia, severe fatty infiltration, and increased expression of adipokines and inflammatory factors in the pancreas. Of note, fatty pancreas has been observed in obese and/or diabetic cases in humans. Preventive effects of anti-hyperlipidemic/anti-diabetic agents on pancreatic cancer have also been shown in humans and animals. Taking this evidence into consideration, modulation of inflammatory factors by anti-inflammatory agents will provide useful data for prevention of pancreatic cancer.

Inflammation-associated cancer development in digestive organs: mechanisms and roles for genetic and epigenetic modulation

Chronic inflammation, regardless of infectious agents, plays important roles in the development of various cancers, particularly in digestive organs, including Helicobacter pylori-associated gastric cancer, hepatitis C virus-positive hepatocellular carcinoma, and colitis-associated colon cancers. Cancer development is characterized by stepwise accumulation of genetic and epigenetic alterations of various proto-oncogenes and tumor-suppressor genes. During chronic inflammation, infectious agents such as H pylori and hepatitis C virus as well as intrinsic mediators of inflammatory responses, including proinflammatory cytokines and reactive oxygen and nitrogen species, can induce genetic and epigenetic changes, including point mutations, deletions, duplications, recombinations, and methylation of various tumor-related genes through various mechanisms. Furthermore, inflammation also modulates the expressions of microRNAs that influence the production of several tumor-related messenger RNAs or proteins. These molecular events induced by chronic inflammation work in concert to alter important pathways involved in normal cellular function, and hence accelerate inflammation-associated cancer development. Among these, recent studies highlighted an important role of activation-induced cytidine deaminase, a nucleotide-editing enzyme essential for somatic hypermutation and class-switch recombination of the immunoglobulin gene, as a genomic modulator in inflammation-associated cancer development.

Familial pancreatic cancer and hereditary syndromes: screening strategy for high-risk individuals

Globally, and almost evenly across nations, a familial disposition can be found in 4-10% of patients with pancreatic cancer (PC). A family history of PC is a risk for this disease and the risk level changes in correlation with the number of affected relatives. Several hereditary syndromes with potential germline mutation also have a high risk for PC; however, little is yet known regarding the genes responsible for familial pancreatic cancer (FPC). Characteristics of FPC cases are similar to those of other familial tumors, including younger onset than in sporadic cases and an ethnic difference (Ashkenazi Jewish > other Caucasian). Other risks resemble those of sporadic cases and include smoking and diabetes mellitus. People with several genetic syndromes, including Peutz-Jeghers syndrome, hereditary pancreatitis, breast-ovarian cancer syndrome, hereditary nonpolyposis colorectal cancer, and familial adenomatous polyposis also have an increased risk of PC. In many countries, but not yet in Japan, screening of these high-risk individuals is now ongoing for the detection of early PC under established familial pancreatic cancer registries. In addition to the ordinary risk factors, such as smoking, diabetes, pancreatitis, cysts, duct ectasia, and intraductal papillary mucinous neoplasm (IPMN), individuals with a family history of PC and hereditary syndromes are expected to be entered into the screening protocol.

Risk factors of familial pancreatic cancer in Japan: current smoking and recent onset of diabetes

OBJECTIVES

In western countries, 7% to 10% of patients with pancreatic cancer (PC) have a familial predisposition to their disease. The aim of this study was to determine the familial susceptibility to PC in Japan.

METHODS

Five hundred seventy-seven patients with PC and 577 age- and gender-matched controls were analyzed for cancer history in their first-degree relative(s) (FDRs) and demographic factors.

RESULTS

The patients with PC were more likely to have an FDR with PC (6.9%) than the controls (2.9%; odds ratio [OR], 2.5; P = 0.02). Three patients (0.5%), but none of the controls, had a family history of PC in multiple FDRs. Smoking, especially current smoking (OR, 1.5; P = 0.005), and diabetes mellitus (OR: 1.7, P = 0.001) were also associated with PC. The odds increased up to 10-fold if the patients were positive for these 3 factors. The patients with familial PC were more likely to be current smokers (40%) and to have diabetes mellitus (32.5%) than the sporadic cases (30.1% and 20.1%; OR, 1.6 and 1.9).

CONCLUSIONS

A family history of PC is a risk of PC in Japan (6.9%) as is a personal history of diabetes and smoking. It is prudent to inform the kindred of patients with familiar PC of the risk of smoking and to follow carefully if they develop diabetes.

Smoking is related to pancreatic fibrosis in humans

OBJECTIVES

Smokers are at risk for pancreatic cancer (PC) and other pancreatic diseases. Cigarette smoking also aggravates the risk of PC in patients with hereditary and chronic pancreatitis (CP) and results in a higher incidence of acute pancreatitis and relapses in CP. Both PC and CP are characterized by a progressive fibrosis. Recently, two studies on rats reported that tobacco smoking is associated with chronic pancreatic inflammation with fibrosis and scarring of pancreatic acinar structures. In this study, we aimed to confirm a relationship between cigarette smoking and pancreatic fibrosis (PF) in humans.

METHODS

In this retrospective study, pancreatic and liver tissue acquired during autopsy was collected and analyzed. PF was scored by assessing severity of intralobular, extralobular, and total PF: grade 0 (normal or mild; 0-25% PF), grade 1 (moderate; 25-50% PF), and grade 2 (severe; >50%). Information on smoking habits was extracted from (electronic) medical records.

RESULTS

Of 900 autopsies performed from January 2005 to December 2007, a minority of patients (n=111) met all inclusion criteria for analysis. Grade 2-3 total PF and intralobular PF was significantly more present in smokers vs. "never-smokers" (total: 42.9 vs. 26.5%, P=0.027 and intralobular: 39.3 vs. 15.6%, P=0.013), whereas no differences could be found between never-smokers and ex-smokers and between ex-smokers and smokers. When we took into account interlobular PF, no differences between all groups were observed. No relationship between PF and age (P=0.893), body mass index (P=0.707), and pancreatic lipomatosis (P=0.916) was observed.

CONCLUSIONS

To our knowledge, no study in humans had studied the effect of tobacco smoking on pancreatic tissue. We have demonstrated for the first time that current cigarette smoking is associated with total PF-specifically, intralobular PF-as compared with nonsmokers.

Genetic reduction of insulin-like growth factor-1 mimics the anticancer effects of calorie restriction on cyclooxygenase-2-driven pancreatic neoplasia

Risk of pancreatic cancer, the fourth deadliest cancer in the United States, is increased by obesity. Calorie restriction (CR) prevents obesity, suppresses carcinogenesis in many models, and reduces serum levels of IGF-1. In the present study, we examined the impact of CR on a model of inflammation-associated pancreatitis and pancreatic dysplasia, with a focus on the mechanistic contribution of systemic IGF-1. Administration of a 30% CR diet for 14 weeks decreased serum IGF-1 levels and hindered pancreatic ductal lesion formation and dysplastic severity, relative to a higher calorie control diet, in transgenic mice overexpressing COX-2 [bovine keratin-5 promoter (BK5.COX-2)]. These findings in CR mice correlated with reductions in Ki-67-positive cells, vascular luminal size, VEGF expression, and phosphorylation and total expression of downstream mediators of the IGF-1 pathway. Cell lines derived from BK5.COX-2 ductal lesions (JC101 cells) formed pancreatic tumors in wild-type FVB mice that were significantly reduced in size by a 14-week CR regimen, relative to the control diet. To further understand the impact of circulating levels of IGF-1 on tumor growth in this model, we orthotopically injected JC101 cells into liver-specific IGF-1-deficient (LID) mice. The approximate 65% reduction of serum IGF-1 levels in LID mice resulted in significantly decreased burden of JC101 tumors, despite modestly elevated levels of circulating insulin and leptin. These data show that CR prevents development of dysplasia and growth of pancreatic cancer through alterations in IGF-1, suggesting that modulation of this pathway with dietary and/or pharmacologic interventions is a promising pancreatic cancer prevention strategy.

How to define patients at high risk for pancreatic cancer

The clinical outcome of patients with pancreatic cancer remains dismal despite recent advances in diagnostic and therapeutic modalities. Several risk factors have been reported regarding the development of pancreatic cancer. These risk factors include family history, accompanying diseases, and lifestyle/personal habits. Family history includes that of pancreatic cancer and hereditary pancreatic cancer syndrome. Accompanying diseases that increase the risk include diabetes mellitus, obesity, chronic pancreatitis, hereditary pancreatic cancer syndrome and intraductal papillary mucinous neoplasms. Lifestyle-associated factors include smoking and diet. Detailed examination of patients with such risk factors is warranted, but the cost-benefit effect should be considered. Thus, patients with more than one risk factor should be carefully followed up, and periodic examination of such patients is necessary to ensure the detection of smaller and less-advanced pancreatic cancer lesions and thus to improve the clinical outcome of patients with pancreatic cancer.

Tissue Transglutaminase (TG2)-Induced Inflammation in Initiation, Progression, and Pathogenesis of Pancreatic Cancer

Pancreatic cancer (PC) is among the deadliest cancers, with a median survival of six months. It is generally believed that infiltrating PC arises through the progression of early grade pancreatic intraepithelial lesions (PanINs). In one model of the disease, the K-ras mutation is an early molecular event during progression of pancreatic cancer; it is followed by the accumulation of additional genetic abnormalities. This model has been supported by animal studies in which activated K-ras and p53 mutations produced metastatic pancreatic ductal adenocarcinoma in mice. According to this model, oncogenic K-ras induces PanIN formation but fails to promote the invasive stage. However, when these mice are subjected to caerulein treatment, which induces a chronic pancreatitis-like state and inflammatory response, PanINs rapidly progress to invasive carcinoma. These results are consistent with epidemiologic studies showing that patients with chronic pancreatitis have a much higher risk of developing PC. In line with these observations, recent studies have revealed elevated expression of the pro-inflammatory protein tissue transglutaminase (TG2) in early PanINs, and its expression increases even more as the disease progresses. In this review we discuss the implications of increased TG2 expression in initiation, progression, and pathogenesis of pancreatic cancer.

Advances in diagnosis, treatment and palliation of pancreatic carcinoma: 1990-2010

Several advances in genetics, diagnosis and palliation of pancreatic cancer (PC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. PC is relatively common as it is the fourth leading cause of cancer related mortality. Most patients present with obstructive jaundice, epigastric or back pain, weight loss and anorexia. Despite improvements in diagnostic modalities, the majority of cases are still detected in advanced stages. The only curative treatment for PC remains surgical resection. No more than 20% of patients are candidates for surgery at the time of diagnosis and survival remains quite poor as adjuvant therapies are not very effective. A small percentage of patients with borderline non-resectable PC might benefit from neo-adjuvant chemoradiation therapy enabling them to undergo resection; however, randomized controlled studies are needed to prove the benefits of this strategy. Patients with unresectable PC benefit from palliative interventions such as biliary decompression and celiac plexus block. Further clinical trials to evaluate new chemo and radiation protocols as well as identification of genetic markers for PC are needed to improve the overall survival of patients affected by PC, as the current overall 5-year survival rate of patients affected by PC is still less than 5%. The aim of this article is to review the most recent high quality literature on this topic.

Total pancreatectomy and islet cell autotransplantation as a means of treating patients with genetically linked pancreatitis

BACKGROUND

For patients with severe chronic pancreatitis, total or completion pancreatectomy with islet cell autotransplantation (IAT) can alleviate pain and avoid the complications of diabetes. Several genetic mutations, specifically, PRSS1, CFTR, and SPINK1, are associated with chronic pancreatitis. Few reports have focused on the benefit of this operation for this subset of patients.

METHODS

Between February 2000 and July 2009, 118 patients were treated with total pancreatectomy and IAT for chronic pancreatitis. Patients with known genetic mutations were then selected for further analysis.

RESULTS

Of the 188 patients, 16 (13.6%) patients were identified as having genetic mutations, including CFTR (n = 10), PRSS1 (n = 4), and SPINK1 (n = 2) mutations. Mean patient age was 31.4 years (range, 15-59) with an equal male-to-female ratio (50:50). Preoperatively, patients required an average of 185 ± 60 morphine equivalents (MEQ) (median, 123 MEQ) for preoperative pain control. No patients were taking insulin before operation. After resection with IAT, patients were discharged from the hospital with a daily average of 22 ± 4 units of insulin with 6 (38%) patients requiring fewer than 15 units of insulin at the time of discharge. At a mean follow-up of 22 months, mean insulin requirements decreased to 15 U/d (P = .0172). A total of 7 (44%) patients required 15 or fewer units daily, and 4 (25%) patients were completely insulin-independent. Average daily narcotic usage at most recent follow-up decreased to 70 MEQ (median, 0) with 10 (63%) patients currently narcotic-independent. Analyses of the 36-item short-form health survey and the McGill Pain Questionnaire demonstrated a significant improvement in quality-of-life parameters and pain assessment.

CONCLUSION

In patients who suffer from genetically linked chronic pancreatitis, pancreatic resection with IAT should be considered as an early therapeutic option to decrease chronic abdominal pain while preserving endogenous endocrine function.

Slight dilatation of the main pancreatic duct and presence of pancreatic cysts as predictive signs of pancreatic cancer: a prospective study

PURPOSE

To prospectively determine whether slight dilatation of the main pancreatic duct and pancreatic cysts detected at ultrasonography (US) are predictive signs of pancreatic cancer.

MATERIALS AND METHODS

The research protocol was approved by the institutional review board, and written informed consent was obtained from all participants. One thousand fifty-eight subjects (age range, 36-80 years; mean, 61.8 years) with various kinds of abnormal US findings in the pancreas were enrolled from 1999 to 2002, after exclusion of pancreatic neoplasm and other malignant diseases. The endpoint was the subsequent development of pancreatic cancer, and the outcome was determined at the end of December 2007. To identify independent predictive variables for the subsequent development of pancreatic cancer, various baseline characteristics were examined by using a Cox regression model and a Cox proportional hazards model. The cumulative incidence of pancreatic cancer was estimated by using the Kaplan-Meyer method.

RESULTS

During the mean follow-up of 75.5 months (+/- 17.3[standard deviation]), pancreatic cancer subsequently developed in 12 of 1058 subjects. The risk of pancreatic cancer was significantly elevated in subjects with slight dilatation (> or = 2.5 mm) of the main pancreatic duct or presence of cyst (s) (> or = 5 mm). The respective hazard ratios were 6.38 (P = .018) and 6.23 (P = .003). For subjects with both findings, the 5-year cumulative risk of pancreatic cancer was 5.62% (95% confidence interval: .37%, 13.03%), and the age-and sex-adjusted hazard ratio compared with the risk in the absence of these findings was 27.50 (P = .002).

CONCLUSION

Main pancreatic duct dilatation (> or = 2.5 mm) and presence of a pancreatic cyst (> or = 5 mm) were both strong independent predictors of the subsequent development of pancreatic cancer. (c) RSNA, 2010.

Angiotensin II regulates the expression of monocyte chemoattractant protein-1 in pancreatic cancer cells

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal cancers with an overall median survival of less than 9 months and a 5-year survival rate of less than 5%. Increasing evidence indicates that inflammation facilitates PDA growth.

DISCUSSION

Angiotensin II (AngII), the principal hormone of the renin-angiotensin system, is actively generated in the pancreas and has been proposed as a key mediator of inflammation. Monocyte chemoattractant protein (MCP)-1 is a chemokine that plays an important role in the recruitment of mononuclear cells into sites of inflammation. In this study, we investigated the potential proinflammatory role of AngII in PDA through studying its effect on MCP-1. AngII significantly increased the expression of MCP-1 mRNA and protein in PDA cells and induced its promoter activity. Constitutive and AngII-induced MCP-1 transcription was inhibited by an AngII type 1 receptor (AT1R) blocker, but was unchanged by an AT2R blocker. AngII activated the phosphorylation of extracellular signal-regulated kinase (ERK)1/2, but not p38 or c-Jun NH2-terminal mitogen-activated protein kinases. Inhibition of ERK1/2 activation reduced the AngII-induced MCP-1 synthesis. AngII induced the activation and nuclear translocation of nuclear factor-kappaB (NF-kappaB), an effect that was inhibited by AT1R blockade. Inhibition of NF-kappaB by pyrrolidine dithiocarbamate decreased the AngII-mediated increase in MCP-1 mRNA. Our data provide a novel insight into an AngII-initiated signal transduction pathway that regulates MCP-1 as a possible inflammatory mechanism in PDA and suggest that AngII blockade may regulate chemokine-induced signal transduction to prevent or reduce inflammation in PDA.

Hereditary pancreatitis in children: surgical implications with special regard to genetic background

PURPOSE

Hereditary pancreatitis (HP) is the primary etiology of chronic pancreatitis during childhood, progressing through recurrent episodes of acute pancreatitis and finally leading to pancreatic insufficiencies. Hereditary pancreatitis is because of mutations of the cationic trypsinogen (PRSS1) gene. Some other genes, such as SPINK1 or CFTR, have been associated with familial idiopathic chronic pancreatitis. The aim of our study was to clearly define diagnostic and therapeutic strategies for HP patients, through an analysis of our study group and a review of the literature.

METHODS

All children admitted from 1995 to 2007 with a final diagnosis of hereditary pancreatitis were restrospectively included in the study. We analyzed all medical records with special attention given to cases involving genetic screening (PRSS1, SPINK1, and CFTR genes).

RESULTS

Ten children were included. Eight had HP with PRSS1 mutation, 2 of them without a familial history of chronic pancreatitis. The 2 others patients had SPINK1 mutations. Three HP patients were operated on for acute complications of pancreatitis and are well with a mean follow-up of 5.5 years. No patient had pancreatic insufficiencies or weight loss.

CONCLUSIONS

Hereditary pancreatitis is associated with severe pancreatitis, with a greater risk of developing pancreatic cancer. It must therefore be diagnosed correctly and treated to prevent its considerable complications.

Peroral pancreatoscopy in the diagnosis and management of intraductal papillary mucinous neoplasia and indeterminate pancreatic duct pathology

Peroral pancreatoscopy (POP) is an exciting modality for the evaluation of pancreatic diseases. It has proved efficacy in the evaluation of suspected intraductal papillary mucinous neoplasia and allows for a determination of the presence and extent of pancreatic duct involvement. When other imaging modalities are inconclusive, POP seems a useful adjunct in the evaluation of indeterminate pancreatic duct strictures and permits tissue sampling under direct vision. Despite recent advances, refinements in endoscope caliber, tip deflection, and optics are still required for more routine application in pancreatic diseases.

Anti-inflammatory effects of the Nigella sativa seed extract, thymoquinone, in pancreatic cancer cells

BACKGROUND

Both hereditary and sporadic forms of chronic pancreatitis are associated with an increased risk of developing pancreatic ductal adenocarcinoma (PDA). Inflammation has been identified as a significant factor in the development of solid tumour malignancies. We have recently shown that thymoquinone (Tq), the major constituent of Nigella sativa oil extract, induced apoptosis and inhibited proliferation in PDA cells. Tq also increased p21 WAF1 expression, inhibited histone deacetylase (HDAC) activity, and induced histone hyperacetylation. HDAC inhibitors have been shown to ameliorate inflammation-associated cancer. In this study, we evaluated the anti-inflammatory potential of Tq in PDA cells in comparison with that of a specific HDAC inhibitor, trichostatin A (TSA).

METHODS

PDA cells were treated with or without Tq (25-75 microM), with or without pre-treatment of tumour necrosis factor (TNF)-alpha (25 ng/ml). The effect of Tq on the expression of different proinflammatory cytokines and chemokines was analysed by real-time polymerase chain reaction (PCR). Luciferase-labelled promoter studies evaluated the effect of Tq on the transcription of monocyte chemoattractant protein-1 (MCP-1) and nuclear factor-kappaB (NF-kappaB). The effect of Tq on the constitutive and TNF-alpha-induced activation and nuclear translocation of NF-kappaB was examined by ELISA and immunohistochemistry.

RESULTS

Tq dose- and time-dependently significantly reduced PDA cell synthesis of MCP-1, TNF-alpha, interleukin (IL)-1beta and Cox-2. At 24 h, Tq almost completely abolished the expression of these cytokines, whereas TSA had a less dramatic effect. Tq, but not TSA, significantly and dose-dependently reduced the intrinsic activity of the MCP-1 promoter. Tq also inhibited the constitutive and TNF-alpha-mediated activation of NF-kappaB in PDA cells and reduced the transport of NF-kappaB from the cytosol to the nucleus.

CONCLUSIONS

Our data demonstrate previously undescribed anti-inflammatory activities of Tq in PDA cells, which are paralleled by inhibition of NF-kappaB. Tq as a novel inhibitor of proinflammatory pathways provides a promising strategy that combines anti-inflammatory and proapoptotic modes of action.

Robust acinar cell transgene expression of CreErT via BAC recombineering

Pancreatic acinar cells are critical in gastrointestinal physiology and pancreatitis and may be involved in pancreatic cancer. Previously, a short rat pancreatic elastase promoter has been widely utilized to control acinar cell transgene expression. However, this partial sequence does not confer robust and stable expression. In this study, we tested the hypothesis that a transgene employing bacterial-artificial-chromosome (BAC) technology to express a tamoxifen-regulated Cre recombinase from a full-length mouse elastase gene (BAC-Ela-CreErT) would be more robust and stable. When founders were crossed with Rosa26 reporter mice nearly 100% of acini expressed beta-galactosidase after tamoxifen treatment. The expression was specific for pancreatic acinar cells and these characteristics have remained stable for 2 years. However, because of high levels of expression in differentiated acinar cells, this construct is tamoxifen independent in approximately 50% of adult acinar cells. This model of pancreatic acinar specific Cre expression is a powerful tool for future transgenic and knockout studies.

Family history is a significant risk factor for pancreatic cancer: results from a systematic review and meta-analysis

Epidemiologic evidence suggests a family history of pancreatic cancer (PC) is a risk factor for the disease, yet the magnitude of risk varies between studies. We performed a systematic review of studies that quantified familial risks of PC, and through a meta-analysis, obtained more precise estimates of familial risk. A MEDLINE search identified published studies that reported relative risks (RR) of PC associated with a family history of the disease. A random effects model was used to summarize study-specific RRs and 95% confidence intervals (CI). Sensitivity and sub-group analyzes were performed. Seven case-control and two cohort studies involving 6,568 PC cases were identified. There was no evidence of statistical heterogeneity between studies (I(2) = 0%; P = 0.483). Results from case-control (RR = 2.82; 95% CI: 1.99-3.66) and cohort (RR = 1.62; 95% CI: 1.28-1.97) studies showed a significant increase in PC risk associated with having an affected relative, with an overall summary RR = 1.80 (95% CI: 1.48-2.12). Similar RR were observed for early (RR = 2.69; 95% CI: 0.56-4.82) and later (RR = 3.41; 95% CI: 0.79-6.03) onset disease in the index case. Data was too sparse to generate an overall summary RR based on the number or type of affected relatives. Individuals with a family history of PC have nearly a two-fold increased risk for developing PC compared to those without such a history. Families with two or more PC cases may benefit from comprehensive risk assessment that involves collection of detailed family history information and data regarding various risk factors for PC, especially smoking history. Those at highest risk may be referred to screening programs and studies; these are important steps toward early detection and greater odds of surviving this disease.

Genetic counseling for nonsyndromic pancreatitis

An appreciation for the background of disease, not to mention the medical management of individuals, may be significantly affected by testing for mutations and genetic variants associated with pancreatitis. Pretest and posttest counseling are essential for patients and families to benefit fully from genetic testing for a susceptibility to develop pancreatitis. The clinician, often working directly with a qualified genetic counselor, must ensure that patients and families appreciate the benefits and limitations of genetic tests, that results are interpreted accurately, and that patients understand implications of information for both their medical care and personal decisions. This article focuses on the approach to genetic counseling for pancreatitis and implications of recent advances.

[Risk factors of pancreatic carcinoma]

History of diabetes, chronic pancreatitis for more than 15 years, and mucinous tumors such as mucinous cystadenoma and intraductal papillary mucinous tumors of the pancreas are all risk factors for pancreatic adenocarcinoma. Recent diabetes with gastrointestinal disorders or weight loss, acute idiopathic and recurrent pancreatitis, the discovery of a cystic lesion in the pancreatic region -all these require exhaustive imaging of the pancreas. In other words, the diagnosis of these benign tumors that risk degeneration into malignancy must not be neglected because practically it is the only way to provide early treatment of pancreatic cancer. Early diagnosis of pancreatic cancer remains difficult today in the absence of reliable serum markers and clearly specific clinical situations at its onset.

Differential roles of the SPINK1 gene mutations in alcoholic and nonalcoholic chronic pancreatitis

BACKGROUND

Risk factors for chronic pancreatitis (CP) are largely unknown except for alcohol. Identification of environmental and genetic risk factors is important for the early diagnosis of CP. We here examined the prevalence of the serine protease inhibitor Kazal type 1 (SPINK1) gene mutations in Japanese patients with CP, and whether the disease course was different between mutation-positive and -negative patients.

METHODS

Genomic DNA was prepared from 96 CP patients and 165 healthy controls. All exons and the promoter region of the SPINK1 gene were amplified by polymerase chain reaction, and directly sequenced. Clinical courses of the patients were reviewed.

RESULTS

The prevalence of [N34S; IVS1-37T>C] and [-215G>A; IVS3+2T>C] mutations was higher in patients with familial (55.6% and 11.1%, respectively) and idiopathic (15.2% and 18.1%) CP than in controls (0.6% and 0%). The N34S and IVS3+2T>C mutations were present in 0% and 4.5% (P<0.05 vs control) of patients with alcoholic CP. Patients with the N34S mutation presented with earlier symptom onset and more dilatation of the main pancreatic duct, followed by more frequent surgical and/or endoscopic intervention and pancreatic cancer development than those without SPINK1 mutations.

CONCLUSIONS

SPINK1 mutations were associated with idiopathic and familial CP, whereas the contribution was less evident in alcoholic CP. Patients with the N34S mutation presented more severe clinical courses, implying that genetic risk assessment might be useful to identify individuals who are likely to develop severe CP, and allow targeted attention to slow or prevent disease progression.

Update on pancreatic cancer and alcohol-associated risk

Ductal adenocarcinoma of the pancreas is characterized by extremely aggressive behavior, with an overall 5-year survival of <4%. Because conventional and specifically tailored therapeutic regimens have little impact on patient survival, epidemiological and molecular research aims at identifying and reducing risk factors. Cigarette smoking, obesity, diabetes mellitus, and chronic pancreatitis are amenable to medical prevention or therapy. Heavy alcohol consumption is an inconsistent single risk factor for pancreatic cancer but may promote carcinogenesis by increasing the risk of diabetes mellitus or chronic pancreatitis. For various agents, the key carcinogenic effect is probably an inflammatory response in the pancreatic tissue. On the molecular level, mutations of oncogenes and tumor suppressor genes, as well as various epigenetic alterations, such as overexpression of growth factors and their receptors, are important in tumorigenesis. Complete and safe surgical resection, together with adjuvant therapy, offers prolonged survival, with 5-year survival rates of approximately 25%. However, for unresectable or disseminated disease, which constitutes the vast majority of cases, treatment is palliative. Despite increasing knowledge about the molecular pathology of pancreatic cancer and despite advances in treatment, the overall course of the disease is dismal, and reinforced efforts to reduce incidence and improve outcome are needed desperately.

[Pancreatic ductal adenocarcinoma and its precursors]

Pancreatic ductal adenocarcinoma is the most frequent malignant pancreatic tumor. It is one of the tumors that has a particularly poor prognosis. Its morphological characteristics are: preferential localization in the head of the pancreas, ductal-glandular tumor structures combined with marked desmoplasia and CEA and MUC1 positivity. Variants of this carcinoma include adenosquamous carcinomas, undifferentiated pleomorphic carcinomas and mixed ductal-endocrine tumors. With the definition of ductal lesions as pancreatic intraepithelial neoplasia, a progression model for pancreatic ductal carcinoma has been developed and corresponding gene alterations have been detected.

Role of inflammation in pancreatic carcinogenesis and the implications for future therapy

BACKGROUND

The link between inflammation and pancreatic cancer has been observed for a number of gastrointestinal neoplasms. This review examines the role of inflammation in pancreatic carcinogenesis and how it can be utilised to develop new therapies against pancreatic cancer.

METHODS

A literature review of Pubmed, Medline and Web of Science databases was undertaken using the key words, pancreatic cancer, inflammation, inducible nitric oxide, interleukins, pro-inflammatory cytokines, cyclooxygenase-2, NF-kappa B, reactive oxygen species, DNA adducts, lipoxygenases, chemoprevention.

RESULTS

Epidemiological evidence and molecular studies both in vitro and in vivo all support the hypothesis that inflammation plays an important in the initiation and progression of pancreatic tumours.

CONCLUSION

Sustained damage caused by chronic inflammation may precede the onset of frank malignancy by a significant interval. As such, suppression of inflammatory changes and oxidative damage, may help delay or even prevent the inception of pancreatic neoplasia.

Molecular targeting of pancreatic disorders

During the last decade significant advances in gene therapy have made it possible to treat various pancreatic disorders in both animal models and in humans. For example, insulin gene delivery to non-beta-cell tissues has been shown to reverse hyperglycemia in diabetic mice, and islet transplantation, based on in vitro differentiation of beta cells and concomitant gene targeting to prevent host autoimmune responses, has become more feasible. Additionally, introduction of the glucokinase regulatory protein and protein kinase C-zeta have been shown to improve glucose tolerance in non-insulin-dependent diabetes mellitus animal models. Pancreatic cancer studies utilize several DNA-based strategies for tumor treatment including introduction of tumor suppressor genes, suppression of oncogenes, suicide gene/prodrug therapy, and restricted replication-competent virus therapy. Tumor-specific targeting is an important part of suicide gene therapy, and tumor-specific promoters are used for cell-specific targeting. Tumor-specific suicide gene therapy directed by the rat insulin promoter has been used to eliminate insulinoma tumors in a mouse model. This review compiles a compendium of information related to the treatment of pancreatic disorders using gene therapy.

Hereditary pancreatitis as the premalignant disease: a Japanese case of pancreatic cancer involving the SPINK1 gene mutation N34S

Mutations in the cationic trypsinogen gene are acknowledged as a risk factor for pancreatic cancer in patients with hereditary pancreatitis. However, whether patients with mutations in other genes, such as the serine protease inhibitor Kazal type 1 (SPINK1) gene, are also at a higher risk of pancreatic cancer remains unknown. We report a case of pancreatic cancer associated with chronic calcifying pancreatitis in a patient with a homozygous N34S mutation in the SPINK1 gene. A 44-year-old woman was hospitalized due to obstructive jaundice. Preoperative examination showed a tumor in the head of the pancreas and multiple pancreatic stones; pancreatoduodenectomy revealed a solid tumor, 3.0 x 2.5 cm in size, in the head of the pancreas, and numerous pancreatic stones throughout the pancreas. Pathologic studies revealed moderately differentiated tubular adenocarcinoma. Mutational analyses of the SPINK1 and PRSS1 genes in members of the patient's family were carried out. The homozygous N34S mutation in the SPINK1 gene was found in the patient and her older sister, who was previously diagnosed with chronic calcific pancreatitis and had undergone the Frey operation. The patient's parents and brother were unaffected carriers of the N34S heterozygous mutation. No family members had any mutations in the cationic trypsinogen gene. To our knowledge, this is the first reported case of chronic pancreatitis accompanied by pancreatic cancer in a patient with the SPINK1 N34S mutation. Although this case does not meet the classic criteria of hereditary pancreatitis, it does suggest that the SPINK1 N34S mutation may be associated with cancer development in patients with hereditary pancreatitis. Further prospective, multicenter trials investigating secondary screening for pancreatic cancer in hereditary pancreatitis are necessary to clarify the role of SPINK1 mutations in the development of pancreatic cancer.

Hereditary pancreatitis

Hereditary pancreatitis is an autosomal dominant condition, which results in recurrent attacks of acute pancreatitis, progressing to chronic pancreatitis often at a young age. The majority of patients with hereditary pancreatitis express one of two mutations (R122H or N29I) in the cationic trypsinogen gene (PRSS1 gene). It has been hypothesised that one of these mutations, the R122H mutation causes pancreatitis by altering a trypsin recognition site so preventing deactivation of trypsin within the pancreas and prolonging its action, resulting in autodigestion. Families with these two mutations have been identified in many countries and there are also other rarer mutations, which have also been linked to hereditary pancreatitis.

Patients with hereditary pancreatitis present in the same way as those with sporadic pancreatitis but at an earlier age. It is common for patients to remain undiagnosed for many years, particularly if they present with non-specific symptoms. Hereditary pancreatitis should always be considered in patients who present with recurrent pancreatitis with a family history of pancreatic disease. If patients with the 2 common mutations are compared, those with the R122H mutation are more likely to present at a younger age and are more likely to require surgical intervention than those with N29I. Hereditary pancreatitis carries a 40% lifetime risk of pancreatic cancer with those patients aged between 50 to 70 being most at risk in whom screening tests may become important.

Pancreatitis as a risk for pancreatic cancer

Chronic pancreatitis clearly predisposes to pancreatic cancer, with early onset-long duration chronic pancreatitis from cystic fibrosis, TP, and HP conferring the highest risk. Chronic pancreatitis is not a critical step, however, but rather one of several conditions that accelerate the accumulation of critical genetic mutations and chromosomal losses necessary for carcinogenesis. Indeed, other germline mutations, environmental factors such as tobacco smoking and alcohol consumption, or dietary factors may also accelerate the pathway to carcinogenesis, and may be synergistic with the conditions created by chronic pancreatitis. Because patients with chronic pancreatitis are at high risk of pancreatic cancer, the physician is faced with decisions on how to manage this risk. Discontinuing smoking and alcohol consumption, and perhaps dietary modification are obvious recommendations for risk reduction. If, however, the patient is older and already in a very high-risk category (e.g., long-standing HP), then screening for cancers must be considered. Inclusion in multicenter trials is recommended, and information on ongoing studies can be obtained through the office of Dr. Whitcomb, or as posted on www.pancreas.org.

Inflammation and the development of pancreatic cancer

OBJECTIVE

Pancreatic cancer has an extremely poor prognosis and the cellular mechanisms contributing to pancreatic cancer are relatively unknown. The goals of this review are to present the epidemiological and experimental data that supports inflammation as a key mediator of pancreatic cancer development, to explain how inflammatory pathways may create an environment that supports tumor formation, and to discuss how the use of novel agents directed at these pathways may be used for the treatment of pancreatic malignancy.

SUMMARY BACKGROUND DATA

Inflammation has been identified as a significant factor in the development of other solid tumor malignancies. Both hereditary and sporadic forms of chronic pancreatitis are associated with an increased risk of developing pancreatic cancer. The combined increase in genomic damage and cellular proliferation, both of which are seen with inflammation, strongly favors malignant transformation of pancreatic cells. Cytokines, reactive oxygen species, and mediators of the inflammatory pathway (e.g., NF-kappaB and COX-2) have been shown to increase cell cycling, cause loss of tumor suppressor function, and stimulate oncogene expression; all of which may lead to pancreatic malignancy. Anti-cytokine vaccines, inhibitors of pro-inflammatory NF-kappaB and COX-2 pathways, thiazolidinediones, and anti-oxidants are potentially useful for the prevention or treatment of pancreatic cancer. Redirection of experimental interests toward pancreatic inflammation and mechanisms of carcinogenesis may identify other novel anti-inflammatory agents or other ways to screen for or prevent pancreatic cancer.

CONCLUSION

Pancreatic inflammation, mediated by cytokines, reactive oxygen species, and upregulated pro-inflammatory pathways, may play a key role in the early development of pancreatic malignancy.

Tumors are unique organs defined by abnormal signaling and context

Many cancer investigations have focussed on the eradication of the cancer cell itself and in doing so, overlook the inherent complexity and heterogeneity of solid tumors. Here, we argue that, in many cases, it is the altered communication within the tumor, rather than mutations per se, that is the defining characteristic of cancer. As a result, tumorigenesis can be indirectly initiated by environmental or inherited factors that affect the stromal cells. We propose that anticancer research might be more effective if aimed at eradicating the cause of abnormality rather than just treating the end result.

Chronic pancreatitis: diagnosis, classification, and new genetic developments

The utilization of recent advances in molecular and genomic technologies and progress in pancreatic imaging techniques provided remarkable insight into genetic, environmental, immunologic, and pathobiological factors leading to chronic pancreatitis. Translation of these advances into clinical practice demands a reassessment of current approaches to diagnosis, classification, and staging. We conclude that an adequate pancreatic biopsy must be the gold standard against which all diagnostic approaches are judged. Although computed tomography remains the initial test of choice for the diagnosis of chronic pancreatitis, the roles of endoscopic retrograde pancreatography, endoscopic ultrasonography, and magnetic resonance imaging are considered. Once chronic pancreatitis is diagnosed, proper classification becomes important. Major predisposing risk factors to chronic pancreatitis may be categorized as either (1) toxic-metabolic, (2) idiopathic, (3) genetic, (4) autoimmune, (5) recurrent and severe acute pancreatitis, or (6) obstructive (TIGAR-O system). After classification, staging of pancreatic function, injury, and fibrosis becomes the next major concern. Further research is needed to determine the clinical and natural history of chronic pancreatitis developing in the context of various risk factors. New methods are needed for early diagnosis of chronic pancreatitis, and new therapies are needed to determine whether interventions will delay or prevent the progression of the irreversible damage characterizing end-stage chronic pancreatitis.