Biomedical subjects

Ralph H Hruban

Publications and source records attributed to Ralph H Hruban.

At least 37 records · Page 2Linked to original sources

PubMed2006

Abdominal lymphangiomas in adults.

Abdominal lymphangiomas are rare benign cystic tumors that can become locally invasive and often require resection. They arise in all ages and have a variable presentation. We performed a retrospective review of a single institution surgical experience with this lesion in adults. The pathology prospective database was reviewed to identify patients with surgically resected abdominal lymphangiomas from January 1986 to May 2004. Retrospective review and follow-up was performed for each patient. The six patients with abdominal lymphangiomas ranged in age from 38 to 66 years. They presented with a variety of signs and symptoms. All underwent CT scan that demonstrated a cystic lesion, but in only one third was the diagnosis made preoperatively. Tumors were located in the retroperitoneum, small bowel mesentery, liver, and pancreas. Five of the six tumors were completely resected. Two of the six required resection of adjacent or involved organs. Follow-up ranged between 6 months and 18 years. All had symptomatic relief after resection, and no patient showed evidence of recurrence in this time period. Abdominal lymphangiomas are rare. The correct diagnosis often remains elusive until tissue is obtained. The treatment of choice is complete surgical resection. When completely resected, these lesions seem not to recur, and the overall prognosis is excellent.

Abdominal Neoplasms↗

PubMed2006

1423 pancreaticoduodenectomies for pancreatic cancer: A single-institution experience.

Pancreaticoduodenectomy (PD) with the possible addition of neoadjuvant or adjuvant therapy is the standard of care in the United States for adenocarcinoma originating in the pancreatic head, neck, and uncinate process. We reviewed 1423 patients who underwent a PD for a malignancy originating in the pancreas at our institution between 1970 and 2006. We examined 1175 PDs for ductal adenocarcinomas in greater detail. Eighteen different histological types of pancreatic cancer were identified; the most common diagnoses included ductal adenocarcinoma, neuroendocrine carcinoma, and IPMN with invasive cancer. Patients with ductal adenocarcinoma were analyzed in detail. The median age was 66 years, with patients in the present decade significantly older (68 years), on average, than patients in the three prior decades (e.g., 60 years in 1970, P = 0.02). The median tumor diameter was 3 cm; 42% of the resections had positive margins and 78% had positive lymph nodes. The perioperative morbidity was 38%. The median postoperative stay declined over time, from 16 days in the 1980s to 8 days in the 2000s (P < 0.001). The perioperative mortality declined from 30% in the 1970s to 1% in the 2000s (P < 0.001). The median survival for all patients with ductal adenocarcinoma was 18 months (1-year survival = 65 %, 2-year survival = 37%, 5-year survival = 18%). In a Cox proportional hazards model, pathological factors having a significant impact on survival included tumor diameter, resection margin status, lymph node status, and histologic grade. This is the largest single-institution experience with PD for pancreatic cancer. Patients who have cancers with favorable pathological features have a statistically significant improved long-term survival.

Adult↗

PubMed2006

Telomere length variation in biliary tract metaplasia, dysplasia, and carcinoma.

Biliary tract carcinoma, including carcinoma of the gallbladder, intrahepatic bile ducts (cholangiocarcinoma), and extrahepatic bile ducts, affects 7500 people in the United States annually, and has an overall 32% 5-year survival rate for disease limited to the mucosa, and a dismal 10% 5-year survival for more advanced disease. The identification of factors involved in the pathogenesis and progression of biliary tract carcinoma is critical for devising effective methods of screening and treatment. Recent evidence suggests that reduction of the length of telomeres, which normally help maintain chromosomal stability, may promote the development and progression of a variety of carcinomas. Using a novel, recently validated telomere fluorescence in situ hybridization method, we examined telomere length in normal and inflamed gallbladder epithelium, metaplasia and dysplasia of the gallbladder, and biliary tract carcinoma to determine whether telomere shortening is associated with neoplastic progression in the biliary tract. Although normal and inflamed gallbladder epithelium demonstrated uniform normal telomere lengths, over half of all metaplastic lesions demonstrated shortened telomeres, supporting prior evidence that metaplastic lesions of the gallbladder are pre-neoplastic. Dysplastic epithelium and invasive carcinomas demonstrated almost universally abnormally short telomeres, indicating that telomere shortening occurs at an early, preinvasive stage of cancer development. In addition, invasive adenocarcinoma of the biliary tract frequently demonstrated intratumoral heterogeneity of telomere lengths. We conclude that telomere shortening is a consistent and early finding in the development of biliary tract carcinoma.

Biliary Tract Neoplasms↗

PubMed2006

Periampullary and pancreatic incidentaloma: a single institution's experience with an increasingly common diagnosis.

BACKGROUND: While incidental masses in certain organs have received particular attention, periampullary and pancreatic incidentalomas (PIs) remain poorly characterized. METHODS: We reviewed 1944 consecutive pancreaticoduodenectomies (PD) over an 8-year period (April 1997 to October 2005). A total of 118 patients (6% of all PDs) presented with an incidental finding of a periampullary or pancreatic mass. The PI patients were analyzed and compared with the rest of the cohort (NI, nonincidentaloma group, n = 1826). RESULTS: Thirty-one percent of the PI patients (n = 37) had malignant disease (versus 76% of the NI patients, P < 0.001), 47% (n = 55) had premalignant disease, and the remaining 22% (n = 26) had little or no risk for malignant progression. The 3 most common diagnoses in the PI group were IPMN without invasive cancer (30%), cystadenoma (17%), and pancreatic ductal adenocarcinoma (10%). The PI group had a higher overall complication rate (55% versus 43%, P = 0.02), due in part to a significantly increased rate of pancreatic fistulas (18.4% PI versus 8.5% NI, P < 0.001). Patients in the PI group with malignant disease had a superior long-term survival (median, 30 months, P = 0.01) compared with patients in the NI group with malignant disease (median, 21 months). CONCLUSIONS: Incidentally discovered periampullary and pancreatic masses comprise a substantial proportion of patients undergoing PD. Roughly three fourths of these lesions are malignant or premalignant, and amenable to curative resection. Resected malignant PIs have favorable pathologic features as compared with resected malignant NIs, and resection of these early lesions in asymptomatic individuals is associated with improved survival, compared with patients with symptomatic disease.

Adolescent↗

PubMed2006

Pancreatic cancer genetic epidemiology consortium.

We have organized the Pancreatic Cancer Genetic Epidemiology (PACGENE) Consortium to identify susceptibility genes in familial pancreatic cancer (FPC). The Consortium comprises seven data collection centers, a statistical genetics core, and a pathology/archival genotyping core. We recruit kindreds containing two or more affected blood relatives ascertained through incident pancreatic adenocarcinoma cases, physician referrals, and/or through Internet recruitment. Accrual to a database containing core clinical, demographic, lifestyle, and family history information from questionnaires is ongoing, along with biospecimen collection. To date, 13,147 patients have been screened for family history, of whom 476 (50% male) probands and 1,912 of their adult (99% unaffected) relatives have been enrolled. Of these, 379 kindreds meet criteria for FPC, having at least two first-degree relatives with pancreatic cancer. Cumulative incidence curves using available age of diagnosis (onset) among and affected relatives were compared with those for incident pancreatic cancer cases reported to 13 U.S. Surveillance Epidemiology and End Results (SEER) sites from 1973 to 2000 (N = 72,700). The mean age +/- SD at diagnosis among 466 PACGENE probands and 670 affected relatives was 64.1 +/- 11.8 and was 65.4 +/- 11.6 for the subset of 369 FPC probands and 429 relatives. Both samples were significantly younger than the mean age at diagnosis in the SEER population (70.0 +/- 12.1 years; differences in curves versus SEER, P < 0.001). Age at diagnosis (excluding probands) in FPC kindreds does not decrease with increasing number of affected individuals. In our sample, younger age at diagnosis was observed whether we grouped probands by recruitment sites that predominantly recruited through high-risk referrals, or through screening all pancreatic cancer patients for family history. Linkage studies are ongoing. The PACGENE Consortium will be a valuable family-based resource that will greatly enhance genetic epidemiology research in pancreatic cancer.

Age of Onset↗

PubMed2006

Assessment of celecoxib pharmacodynamics in pancreatic cancer.

Cyclooxygenase-2 (COX-2) inhibitors are being developed as chemopreventive and anticancer agents. This study aimed to determine the biological effect of the COX-2 inhibitor celecoxib in pancreatic cancer as an early step to the further development of the agent in this disease. Eight patients scheduled for resection of an infiltrating adenocarcinoma of the pancreas were randomized to receive celecoxib at a dose of 400 mg twice daily or placebo for 5 to 15 days before the surgery. In addition, carcinomas from nine additional patients were xenografted in nude mice, expanded, and treated with vehicle or celecoxib for 28 days. Celecoxib markedly decreased the intra-tumor levels of prostaglandin E2 in patient carcinomas and in the heterotransplanted xenografts. However, this effect did not result in inhibition of cell proliferation or microvessel density (as assessed by Ki67 and CD31 staining). In addition, a panel of markers, including bcl-2, COX-1, COX-2, and VEGF, did not change with treatment in a significant manner. Furthermore, there was no evidence of antitumor effects in the xenografted carcinomas. In summary, celecoxib efficiently inhibited the synthesis of prostaglandin E2 both in pancreatic cancer surgical specimens and in xenografted carcinomas but did not exert evident antitumor, antiproliferative, or antiangiogenic effect as a single agent. The direct pancreatic cancer xenograft model proved to be a valuable tool for drug evaluation and biological studies and showed similar results to those observed in resected pancreatic cancer specimens.

Animals↗

PubMed2006

MDCT of intraductal papillary mucinous neoplasm of the pancreas: evaluation of features predictive of invasive carcinoma.

OBJECTIVE: The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT. MATERIALS AND METHODS: Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed. CT was performed with a 4-MDCT scanner with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Arterial and venous phase images were acquired at 25 and 50-60 sec from the start of IV contrast administration. Type of ductal involvement, location, tumor size in branch duct type and combined type lesions, caliber of the main pancreatic duct, caliber of the common bile duct or common hepatic duct, and solid appearance of the lesion were assessed on CT and correlated with pathologic findings for invasive carcinoma. RESULTS: Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively). A solid mass (p < 0.001), dilatation of the common bile duct or common hepatic duct (> or = 15 mm), and the presence of a stent (p = 0.0004) were correlated with the presence of associated invasive carcinoma. CONCLUSION: MDCT helped to predict invasive carcinoma associated with IPMN.

Adenocarcinoma, Mucinous↗

PubMed2006

Multifocal neoplastic precursor lesions associated with lobular atrophy of the pancreas in patients having a strong family history of pancreatic cancer.

We screened 116 patients with a strong family history of pancreatic cancer using a combination of endoscopic ultrasound and computed tomography. Ten of these patients underwent surgical resection at our institution, providing an opportunity to define the morphology of pancreatic precursor lesions in patients with a strong family history of pancreatic cancer. Eight of the 10 pancreata were available and these were entirely submitted for histologic examination. The number of pancreatic intraepithelial neoplasia (PanIN) lesions and intraductal papillary mucinous neoplasms (IPMNs) were compared with age-matched controls. Parenchymal changes were defined. Selected precursor neoplasms from 6 pancreata were microdissected and analyzed for KRAS gene mutations. PanINs were significantly more common in the 8 cases (mean of 10.7% of the duct profiles, range 1.0% to 27.3%) than in the controls (mean 1.9%, range 0% to 9.2%, P<0.01). Different KRAS gene mutations were identified in separately microdissected precursor lesions in 2 of 6 cases. IPMNs were identified in 4 of the 8 cases, including 2 pancreata each having 2 distinct IPMNs. Both the IPMNs and the PanINs, even the low-grade PanIN-1 lesions, were associated with lobular parenchymal atrophy. Some individuals with a strong family history of pancreatic cancer develop multifocal, noninvasive epithelial precursor lesions of the pancreas. PanINs and IPMNs produce obstructive lobular atrophy, and this atrophy is likely the source of the chronic pancreatitis-like changes seen in these patients. The multifocal nature of familial pancreatic neoplasia suggests that surveillance of these patients is warranted after partial pancreatectomy.

Adenocarcinoma, Mucinous↗

PubMed2005

In vivo therapeutic responses contingent on Fanconi anemia/BRCA2 status of the tumor.

PURPOSE: BRCA2, FANCC, and FANCG gene mutations are present in a subset of pancreatic cancer. Defects in these genes could lead to hypersensitivity to interstrand cross-linkers in vivo and a more optimal treatment of pancreatic cancer patients based on the genetic profile of the tumor. EXPERIMENTAL DESIGN: Two retrovirally complemented pancreatic cancer cell lines having defects in the Fanconi anemia pathway, PL11 (FANCC-mutated) and Hs766T (FANCG-mutated), as well as several parental pancreatic cancer cell lines with or without mutations in the Fanconi anemia/BRCA2 pathway, were assayed for in vitro and in vivo sensitivities to various chemotherapeutic agents. RESULTS: A distinct dichotomy of drug responses was observed. Fanconi anemia-defective cancer cells were hypersensitive to the cross-linking agents mitomycin C (MMC), cisplatin, chlorambucil, and melphalan but not to 5-fluorouracil, gemcitabine, doxorubicin, etoposide, vinblastine, or paclitaxel. Hypersensitivity to cross-linking agents was confirmed in vivo; FANCC-deficient xenografts of PL11 and BRCA2-deficient xenografts of CAPAN1 regressed on treatment with two different regimens of MMC whereas Fanconi anemia-proficient xenografts did not. The MMC response comprised cell cycle arrest, apoptosis, and necrosis. Xenografts of PL11 also regressed after a single dose of cyclophosphamide whereas xenografts of genetically complemented PL11(FANCC) did not. CONCLUSIONS: MMC or other cross-linking agents as a clinical therapy for pancreatic cancer patients with tumors harboring defects in the Fanconi anemia/BRCA2 pathway should be specifically investigated.

Animals↗

PubMed2005

Biomarker discovery from pancreatic cancer secretome using a differential proteomic approach.

Quantitative proteomics can be used as a screening tool for identification of differentially expressed proteins as potential biomarkers for cancers. Candidate biomarkers from such studies can subsequently be tested using other techniques for use in early detection of cancers. Here we demonstrate the use of stable isotope labeling with amino acids in cell culture (SILAC) method to compare the secreted proteins (secretome) from pancreatic cancer-derived cells with that from non-neoplastic pancreatic ductal cells. We identified 145 differentially secreted proteins (>1.5-fold change), several of which were previously reported as either up-regulated (e.g. cathepsin D, macrophage colony stimulation factor, and fibronectin receptor) or down-regulated (e.g. profilin 1 and IGFBP-7) proteins in pancreatic cancer, confirming the validity of our approach. In addition, we identified several proteins that have not been correlated previously with pancreatic cancer including perlecan (HSPG2), CD9 antigen, fibronectin receptor (integrin beta1), and a novel cytokine designated as predicted osteoblast protein (FAM3C). The differential expression of a subset of these novel proteins was validated by Western blot analysis. In addition, overexpression of several proteins not described previously to be elevated in human pancreatic cancer (CD9, perlecan, SDF4, apoE, and fibronectin receptor) was confirmed by immunohistochemical labeling using pancreatic cancer tissue microarrays suggesting that these could be further pursued as potential biomarkers. Lastly the protein expression data from SILAC were compared with mRNA expression data obtained using gene expression microarrays for the two cell lines (Panc1 and human pancreatic duct epithelial), and a correlation coefficient (r) of 0.28 was obtained, confirming previously reported poor associations between RNA and protein expression studies.

Biomarkers, Tumor↗

PubMed2005

Identification and characterization of membralin, a novel tumor-associated gene, in ovarian carcinoma.

Identification of new genes in cancer is the key to understand the molecular basis of tumor development as well as provide potential diagnostic markers and therapeutic targets. A novel gene, membralin (GeneBank accession number: DQ005958), was cloned from a human ovarian cancer cell line. Human membralin is unique and does not share significant sequence homology with other human genes, only membralins of other species. The gene contains 11 exons which encode at least two spliced variants in human cancer. The long form of membralin (membralin-1) comprises all 11 exons, encoding a protein of 620-amino acids long and the short form of membralin (membralin-3) contains all exons except for exon 10, encoding a protein of 408 amino acids. Expression of different membralin isoforms depends on tissue type. The long form, membralin-1, is expressed in ovarian and colorectal carcinomas but not in breast or pancreatic carcinomas, which express only the short splice form, membralin-3. Membralin-1-GFP fusion protein demonstrates exclusive cytoplasmic localization. Based on quantitative real-time PCR, in situ hybridization and Western blot analysis, membralin was highly expressed in ovarian serous carcinomas as compared to ovarian surface epithelium (P<0.001). Ovarian carcinomas in effusions demonstrated a significantly higher level of membralin expression than in solid tumors (P<0.001). In conclusion, these findings represent the first characterization of human membralin and suggest that membralin is a novel tumor-associated marker in ovarian serous carcinomas.

Amino Acid Sequence↗

PubMed2005

Classification of types of intraductal papillary-mucinous neoplasm of the pancreas: a consensus study.

Now that more than two decades have passed since the first reports of intraductal papillary-mucinous neoplasms (IPMNs), it has become clear that IPMN consists of a spectrum of neoplasms with both morphological and immunohistochemical variations. At a meeting of international experts on pancreatic precursor lesions held in 2003, it was agreed that a consensus classification of IPMN subtypes should be established to enable a more detailed analysis of the clinicopathological significance of the variations. Based on our experience and on information from the literature, we selected representative histological examples of IPMNs and defined a consensus nomenclature and criteria for classifying variants as distinctive IPMN subtypes including gastric type, intestinal type, pancreatobiliary type, and oncocytic type. These definitions can be used for further analyses of the clinicopathological significance of the variations of IPMN.

Biomarkers, Tumor↗

PubMed2005

Increased prevalence of the BRCA2 polymorphic stop codon K3326X among individuals with familial pancreatic cancer.

Germline BRCA2 mutations predispose to the development of pancreatic cancer. A polymorphic stop codon in the coding region of BRCA2 (K3326X) has been described, and although an initial epidemiological study suggested it was not disease causing, subsequent studies have been inconclusive. To investigate the biological significance of the K3326X polymorphism, we determined its prevalence in patients with sporadic and familial pancreatic cancer. Using a case-control design, we studied 250 patients with resected sporadic pancreatic adenocarcinomas, 144 patients with familial pancreatic adenocarcinoma, 115 spouses of patients with pancreatic cancer, and a disease control group of 135 patients without a personal history of cancer who had undergone cholecystectomy for non-neoplastic disease. The K3326X polymorphism was detected using heteroduplex analysis and DNA sequencing. The BRCA2 K3326X polymorphism was significantly more prevalent in individuals with familial pancreatic cancer: 8/144 (5.6%) vs 3/250 controls (1.2%) (odds ratio, 4.84; 95% CI, 1.27-18.55, P<0.01). One K3326X carrier with familial pancreatic cancer carried an alteration (IVS 16-2A>G) suspected to be deleterious. Excluding this case did not alter the significance of the association (OR: 4.24, P<0.01). In contrast, there was no difference in prevalence among individuals with sporadic pancreatic cancer - 7/250 (OR: 2.37, 95% CI: 0.61-9.27). The increased prevalence of the BRCA2 K3326X polymorphism in patients with familial pancreatic cancer suggests that this polymorphism is deleterious and contributes to pancreatic cancer risk.

Adenocarcinoma↗

PubMed2005

Expression and prognostic significance of 14-3-3sigma and ERM family protein expression in periampullary neoplasms.

Aberrant gene expression in pancreatic ductal adenocarcinomas contributes to the dismal outcome of patients who develop this disease. The 5' region of 14-3-3sigma (stratifin) is hypomethylated in pancreatic adenocarcinomas and is associated with gene overexpression. In multiple experimental systems, ezrin (ERM, Radixin, Moesin) has been identified as being important in the metastatic behavior of pancreatic and other cancers. We investigated the prognostic significance of aberrant expression of 14-3-3sigma and the ERM proteins (Ezrin, radixin, Moesin) in a series of invasive periampullary adenocarcinomas including 300 infiltrating pancreatic adenocarcinomas, 54 ampullary adenocarcinomas, and 33 noninvasive intraductal papillary mucinous neoplasms from patients who underwent pancreaticoduodenal resection at The Johns Hopkins Hospital, Baltimore, MD, between 1991 and 2003. Two-hundred fourty-four (82%) primary infiltrating adenocarcinomas of the pancreas demonstrated positive expression of the 14-3-3sigma, 45 (15%) showed weak immunolabelling, and 9 (3%) were negative. 201 (68%) showed positive immunolabeling of the ERM proteins, 75 (25%) demonstrated weak expression and 20 (7%) no expression. A similar proportion of ampullary cancers showed 14-3-3sigma and ERM protein expression. Expression of 14-3-3sigma and ERM protein was more likely in poorly differentiated cancers (p = 0.00005), and their expression was associated with poor survival in univariate analysis (p = 0.09). By multivariate analysis, patients whose cancers expressed 14-3-3sigma, but not ERM tended to have a poorer prognosis (Hazard ratio, 1.4; 0.9-2.2, p = 0.14). Aberrant expression of 14-3-3sigma may contribute to the outcome of patients with pancreatic ductal adenocarcinoma.

14-3-3 Proteins↗

PubMed2005

Stromal responses to carcinomas of the pancreas: juxtatumoral gene expression conforms to the infiltrating pattern and not the biologic subtype.

If there is a "science" of tumor-stromal interactions, there must be a set of biologic rules that are organ-site dependent. One way to explore this hypothesis would be to compare the patterns of gene expression of two biologically distinct neoplasms that arise within the same organ site. Using nonradioactive in situ hybridization, we evaluated the gene expression patterns of three genes previously shown to be robust markers of the juxtatumoral stroma within eight infiltrating ductal adenocarcinoma of the pancreas (ApoC1, ApoD and MMP11), and compared these patterns to those associated with seven infiltrating colloid and tubular carcinomas arising in association with intraductal papillary mucinous neoplasms (IPMNs), a histologically distinct form of primary carcinoma of the pancreas, two surgically resected samples of chronic pancreatitis and two surgically resected pancreatic cancer liver metastases. Robust juxtatumoral stromal expression was noted for all three markers within all eight conventional infiltrating ductal adenocarcinoma tissues, but not in samples of chronic pancreatitis. Among the carcinomas arising within an IPMN, expression for all three markers was also noted for five of seven infiltrating carcinomas analyzed. However, when labeling for these three markers was analyzed with respect to infiltrative growth pattern, positive labeling was only seen in areas of tubular (ductal-type) growth and not in areas of colloid carcinoma. This observation was further supported by two infiltrating carcinomas arising in an IPMN that showed both tubular and colloid growth patterns within the same neoplasm indicating the host stromal response observed may relate to infiltrative growth pattern rather than the biology of the primary tumor type. Moreover, these robust patterns within conventional infiltrating ductal adenocarcinomas were not retained within matched metastases to the liver, indicating the importance of the tumor microenvironment in the host stromal response. Juxtatumoral stroma was found to be composed of a least two cell types, tumor-infiltrating macrophages and fibroblasts, highlighting the complexity of tumor-stromal interactions within an infiltrating carcinoma. Since the juxtatumoral gene expression response is the strongest indication of direct communication between stroma and cancer cells, we provide evidence of a stereotypical response to infiltrative growth that might predominate in tumor-stromal interactions independent of cancer type, a finding with clinical implications for therapeutic modalities that target this response in human tumors.

Adenocarcinoma, Mucinous↗

PubMed2005

Gene expression profiles in pancreatic intraepithelial neoplasia reflect the effects of Hedgehog signaling on pancreatic ductal epithelial cells.

Invasive pancreatic cancer is thought to develop through a series of noninvasive duct lesions known as pancreatic intraepithelial neoplasia (PanIN). We used cDNA microarrays interrogating 15,000 transcripts to identify 49 genes that were differentially expressed in microdissected early PanIN lesions (PanIN-1B/2) compared with microdissected normal duct epithelium. In this analysis, a cluster of extrapancreatic foregut markers, including pepsinogen C, MUC6, KLF4, and TFF1, was found to be up-regulated in PanIN. Up-regulation of these genes was further validated using combinations of real-time reverse transcription-PCR, in situ hybridization, and immunohistochemistry in a total of 150 early PanIN lesions from 81 patients. Identification of these gastrointestinal transcripts in human PanIN prompted assessment of other foregut markers by both semiquantitative and real-time reverse transcription-PCR, revealing similar up-regulation of Sox-2, Gastrin, HoxA5, GATA4/5/6, Villin and Forkhead 6 (Foxl1). In contrast to frequent expression of multiple gastric epithelial markers, the intestinal markers intestinal fatty acid binding protein, CDX1 and CDX2 were rarely expressed either in PanIN lesions or in invasive pancreatic cancer. Hedgehog pathway activation induced by transfection of immortalized human pancreatic ductal epithelial cells with Gli1 resulted in up-regulation of the majority of foregut markers seen in early PanIN lesions. These data show frequent up-regulation of foregut markers in early PanIN lesions and suggest that PanIN development may involve Hedgehog-mediated conversion to a gastric epithelial differentiation program.

Biomarkers, Tumor↗

PubMed2005

Terminal complement components mediate release of von Willebrand factor and adhesion of platelets in arteries of allografts.

BACKGROUND: Both humoral and cellular immune responses can cause arterial injury in organ transplants, but the manifestations of these different inflammatory mechanisms have not been dissected fully. The present study was designed to define the effects of the terminal complement components on arterial injury in vivo. METHODS: The authors have developed congenic rat strains with a C6 deficiency. The absence of C6 terminates the cascade of complement after C5 cleavage and prevents the assembly of the membrane attack complex. Hearts were transplanted from PVG.1A (RT1) rats to major histocompatibility complex-incompatible C6-deficient (C6-) or C6-sufficient (C6+) PVG.1U (RT1) rats. RESULTS: PVG.1A (C6-) cardiac grafts were rejected acutely (6-7 days) by untreated PVG.1U (C6+) recipients but survived significantly longer in PVG.1U (C6-) recipients (8 to >30 days). Arteries of cardiac allografts in C6+ recipients demonstrated extensive endothelial injury evidenced by release of von Willebrand factor (vWF) and accompanied by platelet aggregation. In contrast, vWF was retained in Weibel-Palade storage granules of arterial endothelial cells in cardiac allografts that were rejected by C6- recipients. In the absence of C6, intimal alterations were limited to lifting of endothelial cells from supporting stroma by infiltrating mononuclear cells, duplicating the clinical lesion described as endotheliitis or intimal arteritis. Delaying graft rejection with a short course of cyclosporine did not decrease vWF release and platelet aggregation in PVG.1U (C6+) recipients. CONCLUSIONS: Mononuclear cell infiltration of the arterial intima occurs in the absence of C6, but C6 deficiency limits the release of vWF from arterial endothelial cells.

Animals↗

PubMed2005

Homozygous deletion of the MTAP gene in invasive adenocarcinoma of the pancreas and in periampullary cancer: a potential new target for therapy.

Methylthioadenosine phosphorylase (MTAP) plays an important role in the salvage pathway for the synthesis of adenosine. Novel chemotherapeutic strategies exploiting the selective loss of MTAP function in cancers have been proposed. The MTAP gene, on chromosome 9p21, is frequently included within homozygous deletions of the p16INK4A/ CDKN2A gene. Biallelic deletions of the p16INK4A/CDKN2A gene are found in 40% of pancreatic cancers, suggesting that the MTAP gene may be frequently inactivated in pancreatic cancer and that selected patients with pancreatic cancer may benefit from therapies targeting this loss. We immunolabeled six xenografted pancreatic cancers with known MTAP and p16INK4A/CDKN2A gene status and found that immunolabeling mirrored gene status. Loss of expression of both MTAP and p16 was observed only in those pancreatic cancers with homozygous deletions that encompassed both the MTAP and p16INK4A/CDKN2A genes. We then immunolabeled a series of 320 microarrayed infiltrating pancreatic adenocarcinomas, 35 biliary adenocarcinomas, 54 ampullary cancers, and 35 noninvasive intraductal papillary mucinous neoplasms. Immunolabeling for MTAP was lost in 91 of the 300 (30%) evaluable pancreatic cancers, 9 of 54 (17%) ampullary cancers, 4 of 33 (12%) biliary cancers, and in 1 of 35 (3%) IPMNs. All neoplasms with loss of MTAP labeling also demonstrated loss of p16 labeling. These results suggest that MTAP expression is lost in approximately 30% of infiltrating pancreatic cancers and in a lower percentage of other periampullary neoplasms, that this loss is the result of homozygous deletions encompassing both the MTAP and p16INK4A/CDKN2A genes. Thus, pancreatic cancer is a promising cancer type in which to explore novel chemotherapeutic strategies to exploit the selective loss of MTAP function.

Adenocarcinoma↗