UMLS:C0149521 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UMLS:C0149521 (chronic pancreatitis)
7,199 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic pancreatitis (CP) is one condition in which epidemiologic studies have demonstrated a definite association with pancreatic adenocarcinoma (PAC). The pathophysiologic and molecular events that either predispose to the development of, or potentiate the growth of, PAC are unknown. Mutation of the codon 12 K-ras gene is one genetic aberration commonly associated with development of PAC. Tumor angiogenesis, or microvascular proliferation of new capillaries, is another pathophysiologic alteration associated with PAC. Although activated ras oncogenes modulate tumor angiogenesis/neovascularization in some tumors, the importance of tumor angiogenesis and the role of K-ras mutation in regulating angiogenesis in CP and PAC are unknown. The aim of this study was to elucidate the relationship between angiogenesis and K-ras mutations in CP and PAC. Tumor angiogenesis and K-ras mutations were evaluated in resected specimens from 25 CP (23 CP plus two CP with PAC) and 16 PAC patients. Tumor angiogenesis was determined using immunohistochemistry of factor VIII-related antigen (FVIIIRAg) and ras mutations were identified by enriched-nested polymerase chain reaction. The mean number of FVIIIRAg-positive blood vessels was significantly (p < 0.005) higher in PAC (23.0 +/- 7.5), CP with a mutant K-ras genome (17.7 +/- 2.8) and CP with a normal K-ras genome (6.5 +/- 3.8), compared to unaffected areas. Codon 12 K-ras mutations were detected in three of 25 CP specimens (12%) and in 15 of 16 PAC specimens (94%). In CP patients with mutant K-ras in their genome, microvessel density was significantly (p < 0.01) elevated, compared to patients with a normal K-ras genome. Statistical analyses (Spearman rank-difference correlation coefficient, Student t test, and chi2 analysis) indicated a significant association between codon 12 K-ras mutations and tumor angiogenesis in both CP and PAC. This study demonstrates a significant association between angiogenesis and K-ras mutation in both PAC and CP. At a minimum, K-ras mutation is associated with the events that increase angiogenesis and it may potentiate or promote tumor angiogenesis.
...
PMID:Tumor angiogenesis in chronic pancreatitis and pancreatic adenocarcinoma: impact of K-ras mutations. 1076 50

Pancreatic cancer belongs to the neoplasms which are characterised by increasing morbidity and mortality. Five-year survival rates of about 0.4% are the norm, and little has changed in the last 70 years. Important etiological factors are age, sex, diet, tobacco smoking, alcohol abuse, occupation and chemical exposure, hereditary chronic pancreatitis, and previous surgery (cholecystectomy and gastrectomy). The majority of exocrine tumours of the pancreas are malignant and 80-90% of them comprise ductal adenocarcinomas. The development and growth of pancreatic carcinoma appears to be caused by a progressive accumulation of multiple genetic abnormalities. This includes oncogene (K-ras) activation, loss of tumour-suppressor p53 gene function and overexpression of growth factors and their ligands. The morphological background for the development of pancreatic carcinoma is ductal epithelial hyperplasia. Current molecular studies have resulted in the identification of cell clones exhibiting the same genetic alterations (K-ras and p53 mutations) as in infiltrating pancreatic carcinoma. Pancreatic intraepithelial neoplasia is only partially defined. The purpose of our study was to evaluate Ki-67 proliferative index and HER-2/neu gene expression in pancreatic intraepithelial proliferative lesions as a sign of increasing epithelial proliferation and dysplasia. Additionally we made an attempt to apply morphometry in demarcating between intraepithelial proliferations of "reactive" type and proliferations with tendency towards progression to cancer. Another aim of the study was to evaluate the expression of bcl-2 and p53 genes in various types of pancreatic intraepithelial proliferations and in pancreatic cancer and to answer the question whether they interact in the process of pancreatic intraepithelial neoplasia. We have also undertaken investigations aiming at determination of the CD44s gene and its v6 isoform expression in intraductal and invasive pancreatic carcinoma, attempting to correlate this expression with the p53 gene mutations. The results of our study indicate that intraductal pancreatic proliferations form a group of heterogeneous lesions possessing different proliferative activity of cells, karyometric features and HER-2/neu, bcl-2 and p53 genes expression. The precancerous lesion in the pancreas may be atypical papillary hyperplasia, which is similar to intraductal carcinoma with respect to the proliferative activity of cells and HER-2/neu, bcl-2 and p53 expression. Pancreatic carcinoma is characterised by high p53, CD44s and CD44v6 expression and low bcl-2 expression. CD44 and p53 genes expression is independent and between bcl-2 and p53 expression there is an inverse correlation. The p53 and CD44v6 expression is the higher the lower is the histological grade of the pancreatic carcinoma.
...
PMID:[Morphologic, morphometric and immunohistochemical studies on pancreatic intraductal hyperplasia and infiltrating carcinoma]. 1090 69

The aim of this study was to prospectively evaluate the diagnostic contribution of the detection of K-ras mutation and measurement of serum CA 19.9 concentrations to cytological diagnosis in patients with clinical suspicion of pancreatic cancer. These patients had either the presence or absence of a pancreatic mass as determined by imaging procedures. A total of 156 consecutive patients with clinical suspicion of pancreatic cancer or for confirmation and follow-up of their chronic pancreatitis disease were included: 84 patients presenting a pancreatic mass (group 1) and 72 patients without a pancreatic mass (group 2). K-ras mutations were detected by a restriction fragment length polymorphism/polymerase chain reaction (RFLP/PCR) method and CA 19.9 by an immunoluminometric assay. When a pancreatic mass was present, cytology offered a high sensitivity, but with a significant number of inconclusive results and K-ras mutational analysis offered a highly specific test. In the absence of a pancreatic mass, CA 19.9 (cut-off 100 U/ml) increased the sensitivity of the diagnosis by cytology and K-ras mutational analysis did not add significant information. Thus both tests contribute to the clinical decision process when pancreatic cancer is clinically suspected and the cytological report is not conclusive.
...
PMID:Prospective evaluation of the contribution of K-ras mutational analysis and CA 19.9 measurement to cytological diagnosis in patients with clinical suspicion of pancreatic cancer. 1104 43

The majority of patients with pancreatic cancer harbour mutations in the K-ras gene. This oncogene may be detected in material obtained at endoscopic retrograde cholangiopancreatography (ERCP), such as bile and pancreatic juice. Since a formal tissue diagnosis may be difficult to establish in pancreatic cancer, detection of K-ras in these materials is an attractive approach to diagnosis. A variety of molecular techniques has been used to detect K-ras, and frequency of the mutation may vary between different populations. In this issue of the European Journal of Gastroenterology and Hepatology, Boadas et al. collected pancreatic juice following secretin stimulation at the time of ERCP, and detected K-ras in 44% of patients with pancreatic cancer. They found the mutation in 16% of patients with chronic pancreatitis. Presence of the mutation, therefore, is not specific enough to recommend its use in the clinical diagnosis of pancreatic cancer. Chronic pancreatitis patients with the mutation may be at higher risk of developing pancreatic cancer than those patients without the mutation, but there is no clear consensus on management and follow-up of these patients.
...
PMID:Does detection of K-ras mutations in pancreatic juice influence clinical decision making? 1171 70

To test the hypothesis that carcinogen exposure and oxidative stress are involved in pancreatic carcinogenesis in susceptible individuals, aromatic DNA adducts and 8-hydroxyguanosine (8-OH-dG) were measured by (32)P-postlabeling and HPLC-EC, respectively, in 31 pancreatic tumors and 13 normal tissues adjacent to the tumor from patients with pancreatic cancer. Normal pancreatic tissues from 24 organ donors, from six patients with non-pancreatic cancers, and from five patients with chronic pancreatitis served as controls. It was found that tissue samples from patients with pancreatic cancer had significantly higher levels of both aromatic DNA adducts and 8-OH-dG compared with control samples. The mean (+/-S.D.) levels of aromatic DNA adducts were 101.8+/-74.6, 26.9+/-26.6, and 11.2+/-6.6 per 10(9) nucleotides in adjacent tissues, tumors, and controls, respectively. The mean (+/-S.D.) levels of 8-OH-dG were 11.9+/-9.6, 10.8+/-10.6, and 6.7+/-4.6 per 10(5) nucleotides in adjacent tissues, tumors, and controls, respectively. Polymorphisms of the CYP1A1, CYP2E1, NAT1, NAT2, GSTM1, MnSOD, and hOGG1 genes were determined in these patients. The level of aromatic DNA adducts was significantly associated with polymorphism of the CYP1A1 gene. No significant correlation was found between the level of 8-OH-dG and the MnSOD, GSTM1, and hOGG1 polymorphisms. However, one novel polymorphism/mutation of the hOGG1 gene was found in a pancreatic tumor. Mutation at codon 12 of the K-ras gene was found in 25 (81%) of 31 pancreatic tumors, including three G-to-A transitions and 22 G-to-T transversions. Patients with the G-to-T mutation had a significantly higher level of aromatic DNA adducts than those with G-to-A or wild-type codon (P=0.02). On the other hand, the K-ras mutation profile was not related to the level of 8-OH-dG. Given the limitation of sample size, these preliminary data lend further support the hypothesis that carcinogen exposure and oxidative stress are involved in pancreatic carcinogenesis.
...
PMID:DNA adducts, genetic polymorphisms, and K-ras mutation in human pancreatic cancer. 1171 88

Chronic pancreatitis causes destruction of the pancreatic gland which leads to tissue fibrosis and regenerative hyperplasia of the epithelium of pancreatic ducts and ductules. Morphological studies revealed distinct proliferative lesions in the pancreatic ducts and ductules adjacent to infiltrating adenocarcinomas of the pancreas. A stepwise progression from mild to severe dysplasia in these hyperplastic lesions has been reported. These lesions, called Pancreatic Intraepithelial Neoplasia (PanIN), harbour a number of well-characterised genetic alterations. Therefore, PanINs were defined as true clonal neoplastic lesions with minimal to moderate and severe cytological and architectural atypia. Almost all of the genetic alterations that have been identified in pancreatic adenocarcinomas have also been identified in PanIN lesions. The prevalence of genetic changes increases as the degree of cytological atypia and histological dysplasia in the PanIN lesions increases. However, some genetic abnormalities have also been found in chronic pancreatitis and normal pancreas, e. g. K-ras mutations. However, due to intratumorous heterogeneity of the genetic changes, further studies are necessary to search for more specific and homogeneous expressed molecular markers. A better understanding of the molecular genetic changes occurring during neoplastic progression in the pancreas will form the basis for future strategies of early tumour detection and improved therapy.
...
PMID:[Pancreatic intraepithelial neoplasia in chronic pancreatitis]. 1175 97

The prevalence of pancreatic cancer in the general population is too low--even in high-prevalence areas such as Northern Europe and North America (8-12 per 10(5) population)--relative to the diagnostic accuracy of present detection methods to permit primary screening in the asymptomatic adult population. The recognition that the lifetime risk of developing pancreatic cancer for patients with hereditary pancreatitis (HP) is extremely high (20% by the age of 60 years and 40% by the age of 70 years) poses considerable challenges and opportunities for secondary screening in those patients without any clinical features of pancreatic cancer. Even for secondary screening, the detection of cancer at a biological stage that would be amenable to cure by surgery (total pancreatectomy) still requires diagnostic modalities with a very high sensitivity and specificity. Conventional radiological imaging methods such as endoluminal ultrasound and endoscopic retrograde pancreatography, which have proved to be valuable in the early detection of early neoplastic lesions in patients with familial pancreatic cancer, may well be applicable to patients with HP but only in those without gross morphological features of chronic pancreatitis (other than parenchymal atrophy). Unfortunately, most cases of HP also have associated gross features of chronic pancreatitis that are likely to seriously undermine the diagnostic value of these conventional imaging modalities. Pre-malignant molecular changes can be detected in the pancreatic juice of patients. Thus, the application of molecular screening in patients with HP is potentially the most powerful method of detection of early pancreatic cancer. Although mutant (mt) K-ras can be detected in the pancreatic juice of most patients with pancreatic cancer, it is also present in patients with non-inherited chronic pancreatitis who do not progress to pancreatic cancer (at least in the short to medium term), as well as increasingly in the older population without pancreatic disease. Nevertheless, the presence of mt-K-ras may identify a genuinely higher-risk group, enabling additional diagnostic imaging and molecular resources to be focussed on such a group. What is clear is that prospective multi-centre studies, such as that being pursued by the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC), are essential for the development of an effective secondary screening programme for these patients.
...
PMID:Molecular diagnosis of early pancreatic ductal adenocarcinoma in high-risk patients. 1212 Feb 29

K-ras point mutation, p53 over-expression, and telomerase activity have been proposed as molecular markers for clinical diagnosis of pancreatic carcinoma. To evaluate the clinical usefulness of these markers, we performed comparative analysis in 61 resected pancreatic samples including 15 intraductal papillary-mucinous tumours (IPMTs), 4 mucinous cystic tumours, 37 ductal adenocarcinomas, and five chronic pancreatitis samples. K-ras point mutation, telomerase activity, and p53 overexpression were analyzed using mutant allele specific amplification, the telomeric repeat amplification protocol, and immunohistochemical staining, respectively. In malignant tumours, K-ras mutation, telomerase activity, and p53 overexpression were detectable in 76, 91, and 46%, respectively, while in benign tumours, these alterations were detectable in 38, 0, and 0%, respectively. Among 15 IPMTs, K-ras mutation was detectable in 4 (80%) of 5 IPMT-adenomas, 4 (80%) of 5 IPMT-carcinomas and 2 (66%) of 3 papillary-mucinous carcinomas, which are invasive carcinomas derived from IPMTs. Telomerase activity was not detectable in IPMT-adenomas, but was detected in all 5 IPMT-carcinomas and 3 papillary-mucinous carcinomas. p53 overexpression was not detected in IPMTs, but was detected in 2 (66%) of 3 papillary-mucinous carcinomas, indicating that telomerase is likely to be activated concomitant with carcinogenesis. These results suggest that telomerase activity is the most useful as a differential diagnostic marker between malignant and benign pancreatic tumours.
...
PMID:Comparative analysis of K-ras point mutation, telomerase activity, and p53 overexpression in pancreatic tumours. 1257 58

Chronic pancreatitis, K-ras oncogene mutations, and the subsequent generation of reactive oxygen species (ROS) appear to be linked to pancreatic cancer. ROS have also been suggested to be mitogenic and capable of stimulating cell proliferation. Cells contain antioxidant enzymes to regulate steady state levels of ROS produced by products of metabolism. The aims of our study were to determine antioxidant enzyme activity in pancreatic cancer cells and correlate enzyme activity with tumor growth, as well as determine whether tumor cell growth could be altered with antioxidant gene transfection. Western blots, enzyme activity, and enzyme activity gels were performed for manganese superoxide dismutase (MnSOD), copper/zinc, catalase, and glutathione peroxidase in normal human pancreas and in the human pancreatic cancer cell lines BxPC-3, Capan-1, MIA PaCa-2, and AsPC-1. Cell population doubling times were determined and correlated with antioxidant enzyme activity. MnSOD was overexpressed in MIA PaCa-2 using an adenoviral vector, and the effect on cell growth was determined. The cell pancreatic cancer lines BxPC-3, MIA PaCa-2, and AsPC-1 had decreased levels of MnSOD immunoreactive protein as well as activity and decreases in MnSOD levels correlated well with increased rates of tumor cell proliferation as determined by cell doubling time. No correlation could be found between cell growth and levels of copper/zinc superoxide dismutase, catalase, or glutathione peroxidase. Enforced expression of MnSOD by adenovirus transfection in the rapid growing cell line MIA PaCa-2 increased MnSOD immunoreactivity and MnSOD activity and decreased growth rate. Overexpression of MnSOD may be effective in growth suppression of pancreatic cancer.
...
PMID:The role of manganese superoxide dismutase in the growth of pancreatic adenocarcinoma. 1264 90

This paper overviewed risk factors of pancreatic cancer. Both genetic and environmental factors may be playing significant roles in the development of pancreatic cancer. Cigarette smoking has been established as a major risk factor for pancreatic cancer, based on findings from almost all epidemiological studies. Long-term smoking cessation may reduce the risk. The evidence that alcohol drinking and coffee consumption increase the risk is not sufficient, although an association with higher level of consumption remains a possibility. Diabetes mellitus, long-standing diabetes in particular, may be a risk factor for pancreatic cancer. Individuals with hereditary pancreatitis or non-hereditary chronic pancreatitis are possibly at increased risk of pancreatic cancer. Higher intake of meat and fat may be associated with an increased risk, while consumption of fruits/vegetables appears to have a protective effect. Individuals with mutations or deletion in such genes as K-ras, p16, p53, DPC4, and BRCA2 increased the risk of developing pancreatic cancer. Cigarette smoking may play a role in the development of these mutations.
...
PMID:An Epidemiological Overview of Environmental and Genetic Risk Factors of Pancreatic Cancer. 1271 18

<< Previous 1 2 3 4 5 6 Next >>