Molecular markers of pancreatic cancer: development and clinical relevance. Langenbecks Arch Surg. 2008;393:883-890. [PMID: 18266003 DOI: 10.1007/s00423-007-0276-0]

Azeliragon inhibits PAK1 and enhances the therapeutic efficacy of AKT inhibitors in pancreatic cancer

Pancreatic cancer is a lethal malignancy for which there is currently no effective treatment strategy. We previously reported that p21-activated kinase 1 (PAK1) is aberrantly expressed in pancreatic cancer patients and that targeted inhibition of PAK1 significantly suppressed pancreatic cancer progression in vitro and in vivo. In this study, we identified the drug azeliragon as a novel inhibitor of PAK1. Cell experiments revealed that azeliragon abolished PAK1 activation and promoted apoptosis in pancreatic cancer cells. Azeliragon was also found to significantly inhibit tumor growth in a pancreatic cancer xenograft model; when combined with afuresertib, an oral pan-AKT kinase inhibitor, azeliragon exhibited a strong synergistic effect against pancreatic cancer cells. Interestingly, afuresertib enhanced the antitumor efficacy of azeliragon in a xenograft mouse model. Collectively, our findings revealed previously unreported aspects of the drug azeliragon, and identified a novel combination strategy for the treatment of pancreatic cancer patients.

An Integrated Data Analysis of mRNA, miRNA and Signaling Pathways in Pancreatic Cancer

Although many genes and miRNAs have been reported for various cancers, pancreatic cancer's specific genes or miRNAs have not been studied precisely yet. Therefore, we have analyzed the gene and miRNA expression profile of pancreatic cancer data in the gene expression omnibus (GEO) database. The microarray-derived miRNAs and mRNAs were annotated by gene ontology (GO) and signaling pathway analysis. We also recognized mRNAs that were targeted by miRNA through the mirDIP database. An integrated analysis of the microarray revealed that only 6 out of 43 common miRNAs had significant differences in their expression profiles between the tumor and normal groups (P value < 0.05 and |log Fold Changes (logFC)|> 1). The hsa-miR-210 had upregulation, whereas hsa-miR-375, hsa-miR-216a, hsa-miR-217, hsa-miR-216b and hsa-miR-634 had downregulation in pancreatic cancer (PC). The analysis results also revealed 109 common mRNAs by microarray and mirDIP 4.1 databases. Pathway analysis showed that amoebiasis, axon guidance, PI3K-Akt signaling pathway, absorption and focal adhesion, adherens junction, platelet activation, protein digestion, human papillomavirus infection, extracellular matrix (ECM) receptor interaction, and riboflavin metabolism played important roles in pancreatic cancer. GO analysis revealed the significant enrichment in the three terms of biological process, cellular component, and molecular function, which were identified as the most important processes associated strongly with pancreatic cancer. In conclusion, DTL, CDH11, COL5A1, ITGA2, KIF14, SMC4, VCAN, hsa-mir-210, hsa-mir-217, hsa-mir-216a, hsa-mir-216b, hsa-mir-375 and hsa-mir-634 can be reported as the novel diagnostic or even therapeutic markers for the future studies. Also, the hsa-mir-107 and hsa-mir-125a-5p with COL5A1, CDH11 and TGFBR1 genes can be introduced as major miRNA and genes on the miRNA-drug-mRNA network. The new regulatory network created in our study could give a deeper knowledge of the pancreatic cancer.

Plasma suPAR may help to distinguish between chronic pancreatitis and pancreatic cancer

OBJECTIVES

SuPAR (soluble urokinase-type plasminogen activator receptor) is a biomarker reflecting the inflammatory state of the human body. Earlier studies suggest that urinary suPAR/creatinine ratio levels are elevated in chronic pancreatitis (CP), and that plasma suPAR (P-suPAR) level is elevated in pancreatic cancer (PC). Our aim was to study the levels of P-suPAR in CP in a long-term prospective follow-up setting to explore the possibility of distinguishing between PC and CP.

MATERIALS AND METHODS

Two patient groups were compared. The first group included 83 patients who were prospectively followed up after their first acute alcohol-induced pancreatitis (AAP) for median 7.0 (range 0.3-9.8) years. Twelve patients in this group developed CP during follow-up, and two patients were further excluded from the CP cohort. The second group consisted of 25 patients operated on for suspicion of pancreatic malignancy and final pathological diagnosis of PC. P-suPAR levels were measured and compared within and between these groups.

RESULTS

P-suPAR levels remained low during follow-up despite the development of CP. P-suPAR was significantly higher in PC patients [median 3.7 (IQR 3.1-4.4) ng/mL] than in CP patients [2.6 (1.8-3.6) ng/mL]; p = .014. A cutoff value of 2.8 ng/mL resulted from a ROC curve with area under curve (AUC) of 0.79 (95% CI 0.61-0.97), p = .009 in differentiation between PC and CP with a sensitivity and a specificity of 88% and 70% respectively.

CONCLUSION

P-suPAR is higher in patients with PC than in patients with CP, and it could thus be used in differentiating between PC and CP.

Glycoengineered nanoparticles enhance the delivery of 5-fluoroucil and paclitaxel to gastric cancer cells of high metastatic potential

Gastric cancer is the third leading cause of cancer-related death worldwide, with half of patients developing metastasis within 5 years after curative treatment. Moreover, many patients cannot tolerate or complete systemic treatment due severe side-effects, reducing their effectiveness. Thus, targeted therapeutics are warranted to improve treatment outcomes and reduce toxicity. Herein, poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with 5-fluorouracil (5-FU) and paclitaxel were surface-functionalized with a monoclonal antibody targeting sialyl-Lewis A (sLeA), a known glycan mediating hematogenous metastasis. Nanoparticles, ranging from 137 to 330 nm, enabled the controlled release of cytotoxic drugs at neutral and acid pH, supporting potential for intravenous and oral administration. Nanoencapsulation also reduced the initial toxicity of the drugs against gastric cells, suggesting it may constitute a safer administration vehicle. Furthermore, nanoparticle functionalization significantly enhanced targeting to sLeA cells in vitro and ex vivo (over 40% in comparison to non-targeted nanoparticles). In summary, a glycoengineered nano-vehicle was successfully developed to deliver 5-FU and paclitaxel therapeutic agents to metastatic gastric cancer cells. We anticipate that this may constitute an important milestone to establish improved targeted therapeutics against gastric cancer. Given the pancarcinomic nature of the sLeA antigen, the translation of this solution to other models may be also envisaged.

Identification of diagnostic upper gastrointestinal cancer tissue type-specific urinary biomarkers

Several potential urinary biomarkers exhibiting an association with upper gastrointestinal tumour growth have been previously identified, of which S100A6, S100A9, rabenosyn-5 and programmed cell death 6-interacting protein (PDCD6IP) were further validated and found to be upregulated in malignant tumours. The cancer cohort from our previous study was subclassified to assess whether distinct molecular markers can be identified for each individual cancer type using a similar approach. Urine samples from patients with cancers of the stomach, oesophagus, oesophagogastric junction or pancreas were analysed by surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry using both CM10 and IMAC30 (Cu²⁺-complexed) chip types and LC-MS/MS-based mass spectrometry after chromatographic enrichment. This was followed by protein identification, pattern matching and validation by western blotting. We found 8 m/z peaks with statistical significance for the four cancer types investigated, of which m/z 2447 and 2577 were identified by pattern matching as fragments of cathepsin-B (CTSB) and cystatin-B (CSTB); both molecules are indicative of pancreatic cancer. Additionally, we observed a potential association of upregulated α-1-antichymotrypsin with pancreatic and gastric cancers, of PDCD6IP, vitelline membrane outer layer protein 1 homolog (VMO1) and triosephosphate isomerase (TPI1) with oesophagogastric junctional cancers, and of complement C4-A, prostatic acid phosphatase, azurocidin and histone-H1 with oesophageal cancer. Furthermore, the potential pancreatic cancer biomarkers CSTB and CTSB were validated independently by western blotting. Therefore, the present study identified two new potential urinary biomarkers that appear to be associated with pancreatic cancer. This may provide a simple, non-invasive screening test for use in the clinical setting.

FAK and paxillin, two potential targets in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer in large part due to late diagnosis and a lack of effective screening tests. In spite of recent progress in imaging, surgery and new therapeutic options for pancreatic cancer, the overall five-year survival still remains unacceptably low. Numerous studies have shown that focal adhesion kinase (FAK) is activated in many cancers including PDAC and promotes cancer progression and metastasis. Paxillin, an intracellular adaptor protein that plays a key role in cytoskeletal organization, connects integrins to FAK and plays a key role in assembly and disassembly of focal adhesions. Here, we have reviewed evidence in support of FAK as a potential therapeutic target and summarized related combinatorial therapies.

Prognostic Value of Preoperative Serum Carcinoembryonic Antigen and Carbohydrate Antigen 19-9 After Resection of Ampullary Cancer

BACKGROUND

The purpose of this study is to investigate the prognostic value of pre-resection serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 after resection of ampullary cancer (AC) in consideration of intestinal (IT) and pancreatobiliary (PT) subtypes.

METHODS

Overall survival (OS) analysis of patients undergoing curative resection of ampullary cancer.

RESULTS

Elevated preoperative CEA (P = 0.013) and CA 19-9 levels (P = 0.030) were significant prognostic factors. Subgroup analysis, however, showed both markers having prognostic value only for the IT subgroup. Pre-resection CEA within normal range identified a subgroup of IT patients with an excellent median survival of 145 months. Compared to other AC patients, this low-risk IT_CEA^- subpopulation was characterized by less frequent advanced pT stages (pT3/pT4, 41 vs. 62%; P = 0.047) and lymph node involvement (pN+, 30 vs. 65%; P = 0.001). OS of this subgroup was significantly better compared to other AC patients (145 vs. 25 months; HR = 3.8; P < 0.001). By multivariate survival analysis, the patient age, the PT subtype, and an elevated pre-resection serum CEA value were identified as independent prognostic variables.

CONCLUSIONS

In AC, the histomorphologic subclassification is highly relevant regarding the prognostic value of preoperative serum CEA and CA 19-9. IT-patients with normal preoperative CEA represent a favorable subgroup with excellent long-term survival.

Developments in miRNA gene signaling pathways in pancreatic cancer

Pancreatic cancer is a devastating malignancy that ranks as the fourth leading cause of cancer-related deaths worldwide. Dismal prognosis is mainly attributable to limited knowledge of the molecular pathogenesis of the disease. miRNAs have been found to be deregulated in pancreatic cancer, affecting several steps of initiation and aggressiveness of the disease by regulating important signaling pathways, such as the KRAS and Notch pathways. Moreover, the effect of miRNAs on regulating cell cycle events and expression of transcription factors has gained a lot of attention. Recent studies have highlighted the application of miRNAs as biomarkers and therapeutic tools. The current review focuses on latest advances with respect to the roles of miRNAs in pancreatic ductal adenocarcinoma associated signaling pathways and miRNA-based therapeutics.

Co-amplification at lower denaturation-temperature PCR combined with unlabled-probe high-resolution melting to detect KRAS codon 12 and 13 mutations in plasma-circulating DNA of pancreatic adenocarcinoma cases

BACKGROUND

The aim of our study was to establish COLD-PCR combined with an unlabeled-probe HRM approach for detecting KRAS codon 12 and 13 mutations in plasma-circulating DNA of pancreatic adenocarcinoma (PA) cases as a novel and effective diagnostic technique.

MATERIALS AND METHODS

We tested the sensitivity and specificity of this approach with dilutions of known mutated cell lines. We screened 36 plasma-circulating DNA samples, 24 from the disease control group and 25 of a healthy group, to be subsequently sequenced to confirm mutations. Simultaneously, we tested the specimens using conventional PCR followed by HRM and then used target-DNA cloning and sequencing for verification. The ROC and respective AUC were calculated for KRAS mutations and/or serum CA 19-9.

RESULTS

It was found that the sensitivity of Sanger reached 0.5% with COLD- PCR, whereas that obtained after conventional PCR did 20%; that of COLD-PCR based on unlabeled-probe HRM, 0.1%. KRAS mutations were identified in 26 of 36 PA cases (72.2%), while none were detected in the disease control and/or healthy group. KRAS mutations were identified both in 26 PA tissues and plasma samples. The AUC of COLD-PCR based unlabeled probe HRM turned out to be 0.861, which when combined with CA 19-9 increased to 0.934.

CONCLUSIONS

It was concluded that COLD-PCR with unlabeled-probe HRM can be a sensitive and accurate screening technique to detect KRAS codon 12 and 13 mutations in plasma-circulating DNA for diagnosing and treating PA.

The promise of methylation on beads for cancer detection and treatment

Despite numerous technical hurdles, the realization of true personalized medicine is becoming a progressive reality for the future of patient care. With the development of new techniques and tools to measure the genetic signature of tumors, biomarkers are increasingly being used to detect occult tumors, determine the choice of treatment and predict outcomes. Methylation of CpG islands at the promoter region of genes is a particularly exciting biomarker as it is cancer-specific. Older methods to detect methylation were cumbersome, operator-dependent and required large amounts of DNA. However, a newer technique called methylation on beads has resulted in a more uniform, streamlined and efficient assay. Furthermore, methylation on beads permits the extraction and processing of miniscule amounts of methylated tumor DNA in the peripheral blood. Such a technique may aid in the clinical detection and treatment of cancers in the future.

Programmed cell death 6 interacting protein (PDCD6IP) and Rabenosyn-5 (ZFYVE20) are potential urinary biomarkers for upper gastrointestinal cancer

PURPOSE

Cancer of the upper digestive tract (uGI) is a major contributor to cancer-related death worldwide. Due to a rise in occurrence, together with poor survival rates and a lack of diagnostic or prognostic clinical assays, there is a clear need to establish molecular biomarkers.

EXPERIMENTAL DESIGN

Initial assessment was performed on urine samples from 60 control and 60 uGI cancer patients using MS to establish a peak pattern or fingerprint model, which was validated by a further set of 59 samples.

RESULTS

We detected 86 cluster peaks by MS above frequency and detection thresholds. Statistical testing and model building resulted in a peak profiling model of five relevant peaks with 88% overall sensitivity and 91% specificity, and overall correctness of 90%. High-resolution MS of 40 samples in the 2-10 kDa range resulted in 646 identified proteins, and pattern matching identified four of the five model peaks within significant parameters, namely programmed cell death 6 interacting protein (PDCD6IP/Alix/AIP1), Rabenosyn-5 (ZFYVE20), protein S100A8, and protein S100A9, of which the first two were validated by Western blotting.

CONCLUSIONS AND CLINICAL RELEVANCE

We demonstrate that MS analysis of human urine can identify lead biomarker candidates in uGI cancers, which makes this technique potentially useful in defining and consolidating biomarker patterns for uGI cancer screening.

K-ras mutational status in cytohistological tissue as a molecular marker for the diagnosis of pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

More clinically meaningful diagnostic tests are needed in pancreatic cancer (PC). K-ras mutations are the most frequently acquired genetic alteration.

METHODS

Original research articles involving the diagnostic accuracy of K-ras mutation detection in PC were selected. Data were presented as forest plots and summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance.

RESULTS

We assessed 19 studies from 16 published articles. The reports were divided into three groups according to the process used to obtain the test material. The summary estimates for detecting K-ras status using an invasive method (fine needle aspiration (FNA), endoscopic retrograde cholangiopancreatography (ERCP), or surgery) were better than cytology: the pooled sensitivity was 77% (95% confidence interval (CI): 74-80%) versus 54% (95% CI: 47-61%); specificity was 88% (95% CI: 85-91%) versus 91% (95% CI: 83-96%); and diagnostic odds ratio (DOR) was 20.26 (11.40-36.03) versus 7.52 (95% CI: 2.80-20.18), respectively. When two procedures were combined, the diagnostic accuracy was markedly improved.

CONCLUSIONS

The analysis of K-ras mutations in pancreatic tissue has a promising diagnostic significance in PC. Further valuable studies are needed.

The Association between Survival and the Pathologic Features of Periampullary Tumors Varies over Time

Introduction. Several histopathologic features of periampullary tumors have been shown to be correlated with prognosis. We evaluated their association with mortality at multiple time points. Methods. A retrospective chart review identified 207 patients with periampullary adenocarcinomas who underwent pancreaticoduodenectomy between January 1, 2001 and December 31, 2009. Clinicopathologic features were assessed, and the data were analyzed using univariate and multivariate methods. Results. In univariate analysis, perineural invasion had a strong association with 1-year mortality (OR 3.03, CI 1.42–6.47), and one lymph node (LN) increase in the LN ratio (LNR) equated with a 5-fold increase in mortality. In contrast, LN status (OR 6.42, CI 3.32–12.41) and perineural invasion (OR 5.44, CI 2.81–10.52) had the strongest associations with mortality at 3 years. Using Cox proportional hazards, perineural invasion (HR 2.61, CI 1.77–3.85) and LN status (HR 2.69, CI 1.84–3.95) had robust associations with overall mortality. Recursive partitioning analysis identified LNR as the most important risk factor for mortality at 1 and 3 years. Conclusions. Overall mortality was closely related to the LNR within the first year, while longer follow-up periods demonstrated a stronger association with perineural invasion and overall LN status. Therefore, the current staging for periampullary tumors may need to be updated to include the LNR.

The clinicopathological significance and relationship of Gli1, MDM2 and p53 expression in resectable pancreatic cancer

AIMS

To study the expression of Gli1, MDM2 and p53 for clinical significance in pancreatic cancer (PC), and their functional relationship in regulating the biological behaviour of PC cells.

METHODS AND RESULTS

Immunohistochemistry showed that the expression of Gli1, MDM2 and p53 was much higher in 57 cases of PC than in paired normal pancreatic tissues, and was positively associated with tumour UICC stage and T stage (P < 0.05). Patients with expression of Gli1 only or coexpression of Gli1 and MDM2 had significantly worse overall survival than patients with negative expression (P < 0.05). RNA interference showed that p53 knockdown increased the protein level of Gli1 but decreased the level of MDM2, and enhanced cell invasion and migration in wild-type p53 Capan-2 cells; whereas Gli1 or MDM2 knockdown did not change p53 expression, but decreased the protein level of MDM2 or Gli1, respectively, and inhibited cell invasion and migration in mutant p53 PANC-1 cells.

CONCLUSIONS

Overexpression of Gli1, MDM2 and mutant p53 contributes to the development and progression of PC, and plays an important role in predicting PC patients' prognosis. Moreover, we report a positive association between Gli1 and MDM2 in PC cells, but their relationship with p53 is dependent on wild-type or mutant p53 status.

Biomarkers for pancreatic cancer: promising new markers and options beyond CA 19-9

Pancreatic adenocarcinoma accounts for nearly 90-95% of exocrine malignant tumors of the pancreas. Traditionally, overexpressed proteins/epitopes such as CA 19-9, CA-50, CEA, and many others were being used as pancreatic cancer tumor markers. The main utility of these biomarkers was in the diagnosis of pancreatic cancer as well as to assess response to chemotherapy and to determine prognosis and to predict tumor recurrence. However, these markers had significant limitations such as lack of sensitivity, false-negative results in certain blood groups, as well as false-positive elevation in the presence of obstructive jaundice. To circumvent these limitations, an extraordinary amount of research is being performed to identify an accurate tumor marker or a panel of markers that could aid in the management of the pancreatic cancer. Although this research has identified a large number and different variety of biomarkers, few hold future promise as a preferred marker for pancreatic cancer. This review provides an insight into exciting new areas of pancreatic biomarker research such as salivary, pancreatic juice, and stool markers that can be used as a noninvasive test to identify pancreatic cancer. This manuscript also provides a discussion on newer biomarkers, the role of microRNAs, and pancreatic cancer proteomics, which have the potential to identify a preferred tumor marker for pancreatic adenocarcinoma. This review further elaborates on important genetic changes associated with the development and progression of pancreatic cancer that holds the key for the identification of a sensitive biomarker and which could also serve as a therapeutic target.

Novel methylation biomarker panel for the early detection of pancreatic cancer

PURPOSE

Pancreatic cancer is the fourth leading cause of cancer deaths and there currently is no reliable modality for the early detection of this disease. Here, we identify cancer-specific promoter DNA methylation of BNC1 and ADAMTS1 as a promising biomarker detection strategy meriting investigation in pancreatic cancer.

EXPERIMENTAL DESIGN

We used a genome-wide pharmacologic transcriptome approach to identify novel cancer-specific DNA methylation alterations in pancreatic cancer cell lines. Of eight promising genes, we focused our studies on BNC1 and ADAMTS1 for further downstream analysis, including methylation and expression. We used a nanoparticle-enabled methylation on beads (MOB) technology to detect early-stage pancreatic cancers by analyzing DNA methylation in patient serum.

RESULTS

We identified two novel genes, BNC1 (92%) and ADAMTS1 (68%), that showed a high frequency of methylation in pancreatic cancers (n = 143), up to 100% in PanIN-3 and 97% in stage I invasive cancers. Using the nanoparticle-enabled MOB technology, these alterations could be detected in serum samples (n = 42) from patients with pancreatic cancer, with a sensitivity for BNC1 of 79% [95% confidence interval (CI), 66%-91%] and for ADAMTS1 of 48% (95% CI, 33%-63%), whereas specificity was 89% for BNC1 (95% CI, 76%-100%) and 92% for ADAMTS1 (95% CI, 82%-100%). Overall sensitivity using both markers is 81% (95% CI, 69%-93%) and specificity is 85% (95% CI, 71%-99%).

CONCLUSIONS

Promoter DNA methylation of BNC1 and ADAMTS1 is a potential biomarker to detect early-stage pancreatic cancers. Assaying the promoter methylation status of these genes in circulating DNA from serum is a promising strategy for early detection of pancreatic cancer and has the potential to improve mortality from this disease.

Trends in laboratory test volumes for Medicare Part B reimbursements, 2000-2010

CONTEXT

Changes in reimbursements for clinical laboratory testing may help us assess the effect of various variables, such as testing recommendations, market forces, changes in testing technology, and changes in clinical or laboratory practices, and provide information that can influence health care and public health policy decisions. To date, however, there has been no report, to our knowledge, of longitudinal trends in national laboratory test use.

OBJECTIVE

To evaluate Medicare Part B-reimbursed volumes of selected laboratory tests per 10,000 enrollees from 2000 through 2010.

DESIGN

Laboratory test reimbursement volumes per 10,000 enrollees in Medicare Part B were obtained from the Centers for Medicare & Medicaid Services (Baltimore, Maryland). The ratio of the most recent (2010) reimbursed test volume per 10,000 Medicare enrollees, divided by the oldest data (usually 2000) during this decade, called the volume ratio, was used to measure trends in test reimbursement. Laboratory tests with a reimbursement claim frequency of at least 10 per 10,000 Medicare enrollees in 2010 were selected, provided there was more than a 50% change in test reimbursement volume during the 2000-2010 decade. We combined the reimbursed test volumes for the few tests that were listed under more than one code in the Current Procedural Terminology (American Medical Association, Chicago, Illinois). A 2-sided Poisson regression, adjusted for potential overdispersion, was used to determine P values for the trend; trends were considered significant at P < .05.

RESULTS

Tests with the greatest decrease in reimbursement volumes were electrolytes, digoxin, carbamazepine, phenytoin, and lithium, with volume ratios ranging from 0.27 to 0.64 (P < .001). Tests with the greatest increase in reimbursement volumes were meprobamate, opiates, methadone, phencyclidine, amphetamines, cocaine, and vitamin D, with volume ratios ranging from 83 to 1510 (P < .001).

CONCLUSIONS

Although reimbursement volumes increased for most of the selected tests, other tests exhibited statistically significant downward trends in annual reimbursement volumes. The observed changes in reimbursement volumes may be explained by disease prevalence and severity, patterns of drug use, clinical or laboratory practices, and testing recommendations and guidelines, among others. These data may be useful to policy makers, health systems researchers, laboratory directors, and industry scientists to understand, address, and anticipate trends in laboratory testing in the Medicare population.

A novel serum metabolomics-based diagnostic approach to pancreatic cancer

BACKGROUND

To improve the prognosis of patients with pancreatic cancer, more accurate serum diagnostic methods are required. We used serum metabolomics as a diagnostic method for pancreatic cancer.

METHODS

Sera from patients with pancreatic cancer, healthy volunteers, and chronic pancreatitis were collected at multiple institutions. The pancreatic cancer and healthy volunteers were randomly allocated to the training or the validation set. All of the chronic pancreatitis cases were included in the validation set. In each study, the subjects' serum metabolites were analyzed by gas chromatography mass spectrometry (GC/MS) and a data processing system using an in-house library. The diagnostic model constructed via multiple logistic regression analysis in the training set study was evaluated on the basis of its sensitivity and specificity, and the results were confirmed by the validation set study.

RESULTS

In the training set study, which included 43 patients with pancreatic cancer and 42 healthy volunteers, the model possessed high sensitivity (86.0%) and specificity (88.1%) for pancreatic cancer. The use of the model was confirmed in the validation set study, which included 42 pancreatic cancer, 41 healthy volunteers, and 23 chronic pancreatitis; that is, it displayed high sensitivity (71.4%) and specificity (78.1%); and furthermore, it displayed higher sensitivity (77.8%) in resectable pancreatic cancer and lower false-positive rate (17.4%) in chronic pancreatitis than conventional markers.

CONCLUSIONS

Our model possessed higher accuracy than conventional tumor markers at detecting the resectable patients with pancreatic cancer in cohort including patients with chronic pancreatitis.

IMPACT

It is a promising method for improving the prognosis of pancreatic cancer via its early detection and accurate discrimination from chronic pancreatitis.

Preoperative CEA and CA 19-9 are prognostic markers for survival after curative resection for ductal adenocarcinoma of the pancreas - a retrospective tumor marker prognostic study

BACKGROUND

The prognosis for patients with ductal adenocarcinoma of the pancreas (PDAC) remains poor even after curative resection. Carbohydrate antigen 19-9 (CA 19-9) and the carcinoembryonic antigen (CEA) are the most widely used serum-based tumor markers for the diagnosis and follow up of pancreatic cancer. In our analysis we aim to assess the prognostic value of a combination of both tumor markers in patients with pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

Between 01/1995 and 08/2012 we performed a total of 264 pancreatic resections due to PDAC. Patients were stratified into 3 groups in regard to their preoperative tumor marker levels. Survival was compared between the groups using Kaplan Meier analysis and log rank test. Univariate subgroup analysis and multivariate analysis were performed.

RESULTS

For 259 cases complete follow up could be obtained. In patients with low preoperative CEA and CA 19-9 levels (group 1 n = 91) the mean survival was 33.3 month (CI 95% 25.1-41.5). If one of the analyzed tumor markers (CEA/CA19-9) was preoperatively elevated above the cut-off level (group 2 n = 106) mean survival was 28.5 month (CI 95% 22.1-35.1). 62 patients showed preoperative elevation of both, CEA and CA 19-9 (group 3); mean survival in this group was 23.9 month (CI 95% 13.9-33.9), p > 0.01. Multivariate analysis confirmed preoperative CEA/CA 19-9 level as independent prognostic factor (HR 1.299).

CONCLUSION

Preoperative CEA and CA 19-9 levels correlate with patient prognosis after curative pancreatic resection due to PDAC. This is especially true for the most frequently pT 3/4 stages of PDAC. Even if CEA and CA 19-9 might not be appropriate for screening, its serum levels should therefore be determined prior to operation and taken into account when resectability or operability is doubtful.

Mucin (Muc) expression during pancreatic cancer progression in spontaneous mouse model: potential implications for diagnosis and therapy

Background

Pancreatic cancer (PC) is a lethal malignancy primarily driven by activated Kras mutations and characterized by the deregulation of several genes including mucins. Previous studies on mucins have identified their significant role in both benign and malignant human diseases including PC progression and metastasis. However, the initiation of MUC expression during PC remains unknown because of lack of early stage tumor tissues from PC patients.

Methods

In the present study, we have evaluated stage specific expression patterns of mucins during mouse PC progression in (Kras^G12D;Pdx1-Cre (KC)) murine PC model from pancreatic intraepithelial neoplasia (PanIN) to pancreatic ductal adenocarcinoma (PDAC) by immunohistochemistry and quantitative real-time PCR.

Results

In agreement with previous studies on human PC, we observed a progressive increase in the expression of mucins particularly Muc1, Muc4 and Muc5AC in the pancreas of KC (as early as PanIN I) mice with advancement of PanIN lesions and PDAC both at mRNA and protein levels. Additionally, mucin expression correlated with the increased expression of inflammatory cytokines IFN-γ (p < 0.0062), CXCL1 (p < 0.00014) and CXCL2 (p < 0.08) in the pancreas of KC mice, which are known to induce mucin expression. Further, we also observed progressive increase in inflammation in pancreas of KC mice from 10 to 50 weeks of age as indicated by the increase in the macrophage infiltration. Overall, this study corroborates with previous human studies that indicated the aberrant overexpression of MUC1, MUC4 and MUC5AC mucins during the progression of PC.

Conclusions

Our study reinforces the potential utility of the KC murine model for determining the functional role of mucins in PC pathogenesis by crossing KC mice with corresponding mucin knockout mice and evaluating mucin based diagnostic and therapeutic approaches for lethal PC.

Pancreatic ductal adenocarcinoma is associated with a distinct urinary metabolomic signature

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with poor prognosis in part due to the lack of early detection and screening methods. Metabolomics provides a means for noninvasive screening of tumor-associated perturbations in cellular metabolism.

METHODS

Urine samples of PDAC patients (n = 32), healthy age and gender-matched controls (n = 32), and patients with benign pancreatic conditions (n = 25) were examined using (1)H-NMR spectroscopy. Targeted profiling of spectra permitted quantification of 66 metabolites. Unsupervised (principal component analysis, PCA) and supervised (orthogonal partial-least squares discriminant analysis, OPLS-DA) multivariate pattern recognition techniques were applied to discriminate between sample spectra using SIMCA-P(+) (version 12, Umetrics, Sweden).

RESULTS

Clear distinction between PDAC and controls was noted when using OPLS-DA. Significant differences in metabolite concentrations between cancers and controls (p < 0.001) were noted. Model parameters for both goodness of fit, and predictive capability were high (R (2) = 0.85; Q (2) = 0.59, respectively). Internal validation methods were used to confirm model validity. Sensitivity and specificity of the multivariate OPLS-DA model were summarized using a receiver operating characteristics (ROC) curve, with an area under the curve (AUROC) = 0.988, indicating strong predictive power. Preliminary analysis revealed an AUROC = 0.958 for the model of benign pancreatic disease compared with PDAC, and suggest that the cancer-associated metabolomic signature dissipates following RO resection.

CONCLUSIONS

Urinary metabolomics detected distinct differences in the metabolic profiles of pancreatic cancer compared with healthy controls and benign pancreatic disease. These preliminary results suggest that metabolomic approaches may facilitate discovery of novel pancreatic cancer biomarkers.

Down regulation of CAII is associated with tumor differentiation and poor prognosis in patients with pancreatic cancer

BACKGROUND AND OBJECTIVES

Altered expression of carbonic anhydrase (CA)I and II associated with human carcinogenesis. But there was no definite study investigating their expression for clinical significance in pancreatic cancer and effect of the CA inhibitor acetazolamide (AZ) on regulation biological behavior of pancreatic cancer cells.

METHODS

Immunohistochemistry, immunofluorescence, immunoblot, and qRT-PCR were used to detect CAI, II, and p53 expression. Tumor cell viability, apoptosis, and invasion assays were used to investigate the effect of AZ on pancreatic cancer cells.

RESULTS

Expression of CAI and p53 was increased in pancreatic cancer than that in paired non-cancerous tissues (P = 0.021; P = 0.007), whereas CAII was down-regulated in pancreatic cancer (P = 0.001). CAI overexpression was associated with tumor differentiation and negatively with vascular invasion (P = 0.015 and P = 0.018, respectively), while overexpression of CAII was associated with tumor differentiation (P = 0.017) and a better prognosis of pancreatic cancer patients (P = 0.017), and was an independent prognostic indicator (P = 0.011). p53 overexpression was related with lymph node metastasis (P = 0.032) and TNM stage (P = 0.016). Treatment with AZ inhibited tumor cell validity, invasion, and induced apoptosis in some of six pancreatic cancer cells.

CONCLUSION

This study suggests the clinical significance of CAI, CAII and p53 expression in pancreatic cancer and provides evidence for AZ as a potential target for controlling pancreatic cancer.

Overcoming nucleoside analog chemoresistance of pancreatic cancer: a therapeutic challenge

Clinical refractoriness to nucleoside analogs (e.g., gemcitabine, capecitabine) is a major scientific problem and is one of the main reasons underlying the extremely poor prognostic state of pancreatic cancer. The drugs' effects are suboptimal partly due to cellular mechanisms limiting their transport, activation, and overall efficacy. Nonetheless, novel therapeutic approaches are presently under study to circumvent nucleoside analog resistance in pancreatic cancer. With these new approaches come additional challenges to be addressed. This review describes the determinants of chemoresistance in the gemcitabine cytotoxicity pathways, provides an overview of investigational approaches for overcoming chemoresistance, and discusses new challenges presented. Understanding the future directions of the field may assist in the successful development of novel treatment strategies for enhancing chemotherapeutic efficacy in pancreatic cancer.

The regulatory roles of miRNA and methylation on oncogene and tumor suppressor gene expression in pancreatic cancer cells

Carcinogenesis is driven by an accumulation of mutations and genetic lesions, which leads to activation of oncogenes and inactivation of tumor suppressor genes. However, the molecular mechanisms by which the expression of these genes was regulated in pancreatic cancer remains unclear. In this study, we investigated the regulatory effects of microRNA and methylation on the expression of k-ras, TP53 and PTEN genes in pancreatic cancer cells. The protein and miRNA levels were measured by Western blotting and Northern blotting, respectively. Xenograft pancreatic tumor models were established by inoculating BxPC-1, Capan-2, and Panc-1 tumor cells into athymic nu/nu mice. A disparate level of KRAS, p53, PTEN, Dnmts, and Dicer 1 proteins as well as let-7i, miR-22, miR-143, and miR-29b miRNA was observed in BxPC-1, Capan-2, and Panc-1 cells. Knockdown of Dicer 1 expression in BxPC-3 and Panc-1 cells resulted in significant increases in KRAS, p53, PTEN, and Dnmts protein levels and significant decreases in miR-22, miR-143, let-7i, and miR-29b expression. Knockdown of Dicer 1 expression in Capan-2 cells significantly increased p53 and PTEN expression, while significantly decreased miR-22 and miR-143 expression, but had no effects on PTEN, Dnmts, let-7i, and miR-29b expression. Knockdown of Dicer 1 expression significantly inhibited xenograft BxPC-3 tumor growth, but promoted xenograft Panc-1 tumor growth. In contrast, knockdown of Dicer 1 expression had no effect on xenograft Capan-2 tumor growth. Our study suggested that different pancreatic cancer cell lines exhibited obvious discrepancies in gene expression profiles, implying that different molecular mechanisms are involved in the carcinogenesis of pancreatic cancer subclasses. Our study highlighted the importance of personalized therapy.

The predictive role of p16 deletion, p53 deletion, and polysomy 9 and 17 in pancreatic ductal adenocarcinoma

In this study, we investigated p53 and p16 deletions, and chromosome 9 and 17 amplifications in pancreatic ductal adenocarcinoma (PDAC), and further analyzed their associations with clinical characteristics and prognosis of PDAC. A total of 32 PDAC and 23 peritumoral tissues were collected. Molecular abnormalities of CEP9/p16 and CEP17/p53 were detected using Fluorescence in situ hybridization (FISH). Deletions of p16 and p53 were detected in 50 % and 65.7 % of PDAC, respectively. Polysomy 9 and 17 were identified in 75 % and 71.8 % of PDAC, respectively. No p16 and p53 deletion, polysomy 9 and 17 were identified in peritumoral tissues. We also observed significant correlations of p16 deletion, polysomy 9 and 17 with shorter survival of PDAC. P16 deletion, polysomy 9 and 17 are predictive markers for poor prognosis of PDAC patients, but p53 deletion is not associated with the clinical characteristics and prognosis of PDAC.

Genetically engineered mouse models: closing the gap between preclinical data and trial outcomes

The high failure rate of late-stage human clinical trials, particularly in oncology, predicates the need for improved translation of preclinical data from mouse tumor models into clinical predictions. Genetically engineered mouse models (GEMM) may fulfill this need, because they mimic spontaneous and autochthonous disease progression. Using oncogenic Kras-driven GEMMs of lung and pancreatic adenocarcinoma, we recently showed that these models can closely phenocopy human therapeutic responses to standard-of-care treatment regimens. Here we review the successful preclinical application of such GEMMs, as well as the potential for discovering predictive biomarkers and gaining mechanistic insights into clinical outcomes and drug resistance in human cancers.

Identification of serum biomarker signatures associated with pancreatic cancer

Pancreatic cancer is an aggressive disease with poor prognosis, due, in part, to the lack of disease-specific biomarkers that could afford early and accurate diagnosis. With a recombinant antibody microarray platform, targeting mainly immunoregulatory proteins, we screened sera from 148 patients with pancreatic cancer, chronic pancreatitis, autoimmune pancreatitis (AIP), and healthy controls (N). Serum biomarker signatures were derived from training cohorts and the predictive power was evaluated using independent test cohorts. The results identified serum portraits distinguishing pancreatic cancer from N [receiver operating characteristics area under the curve (AUC) of 0.95], chronic pancreatitis (0.86), and AIP (0.99). Importantly, a 25-serum biomarker signature discriminating pancreatic cancer from the combined group of N, chronic pancreatitis, and AIP was determined. This signature exhibited a high diagnostic potential (AUC of 0.88). In summary, we present the first prevalidated, multiplexed serum biomarker signature for diagnosis of pancreatic cancer that may improve diagnosis and prevention in premalignant diseases and in screening of high-risk individuals.

Serum concentrations of CA 125, CA 15-3, CA 19-9 and CEA in normal pregnancy: a longitudinal study

PURPOSE

Although cancer diagnosed during pregnancy is rare, the coexistence of pregnancy and malignancy becomes more common in view of prolongation of reproductive age. Therefore, it is important that the specificity of a tumor marker be evaluated during pregnancy to avoid misinterpretation in the follow-up of a pregnant cancer patient. The present study aims to investigate the serum concentrations of CA-125, CA 15-3, CA 19-9 and CEA in healthy pregnant women through gestation.

METHODS

In this prospective study, we followed thirty healthy pregnant women. Blood samples were obtained during each trimester of pregnancy (10-12, 22-24 and 34-36 weeks). The maternal serum levels of CA-125, CA 15-3, CA 19-9 and CEA were measured using electrochemiluminescence immunoassay.

RESULTS

There was no difference between the first and second trimester serum levels of CA 125, CEA and CA 19-9. However, serum CA 125 levels in third trimester were found to be significantly elevated in pregnants compared to the second trimester (median values 19.6 vs. 15.6 IU/mL, p = 0,009). Similarly, the serum CEA levels in third trimester were significantly higher than those of second trimester (median values 1.1 vs. 0.7 ng/ml, p = 0.001). It is also found that CEA and CA 19-9 assay values were significantly elevated in the third trimester of pregnancy when compared with the first trimester of pregnancy (CEA median values 1.1 vs. 0.7 ng/ml, p = 0.02 and CA 19-9 median values 11.6 vs. 7.7 IU/mL, p = 0,02). Three trimester had statistically similar levels for serum CA 15-3 (median values 17.5, 19.7 and 18.3 U/mL, respectively). The four tumor markers assay values were found generally within the normal range.

CONCLUSIONS

These findings suggest that maternal serum levels of CA 125, CEA and CA 19-9 were increased during third trimester of pregnancy. However, these elevations were within the normal range. CA 15-3 is independent of gestation and reliable tumor markers in monitoring malignancy in pregnant patients.

Advances in biomarker research for pancreatic cancer

Pancreatic cancer (PC) is a leading cause of cancer related deaths in United States. The lack of early symptoms results in latestage detection and a high mortality rate. Currently, the only potentially curative approach for PC is surgical resection, which is often unsuccessful because the invasive and metastatic nature of the tumor masses makes their complete removal difficult. Consequently, patients suffer relapses from remaining cancer stem cells or drug resistance that eventually lead to death. To improve the survival rate, the early detection of PC is critical. Current biomarker research in PC indicates that a serum carbohydrate antigen, CA 19-9, is the only available biomarker with approximately 90% specificity to PC. However, the efficacy of CA 19-9 for assessing prognosis and monitoring patients with PC remains contentious. Thus, advances in technology and the detection of new biomarkers with high specificity to PC are needed to reduce the mortality rate of pancreatic cancer.

The predictive value of mean platelet volume in differential diagnosis of non-functional pancreatic neuroendocrine tumors from pancreatic adenocarcinomas

OBJECTIVE

The aim of the present study is to evaluate in a retrospective manner the diagnostic value of mean platelet volume (MPV) in pancreatic adenocarcinomas and pancreatic neuroendocrine tumors (PNETs).

PATIENTS AND METHODS

A total of 92 patients, who were admitted for pancreatic adenocarcinoma (n=76) and PNET (n=16) between March 2007 and December 2009, were analyzed retrospectively for demographics and clinical information.

RESULTS

Thirty-nine patients (51.3%) had a resectable, whereas 37 patients (48.7%) had an unresectable pancreatic adenocarcinoma. Nine patients (56.3%) had a non-functional PNET, 6 patients (37.5%) had an insulinoma, and the remaining one patient had a gastrinoma. The mean age was 59.3±10.5 for pancreatic adenocarcinomas and 45.1±10.6 for PNETs. The mean age at diagnosis was significantly higher in patients with pancreatic adenocarcinomas than the patients with PNET (p<0.001). Preoperative mean hemoglobin levels were significantly lower in patients with pancreatic adenocarcinoma than those with PNET (12.4±1.8g/dl vs 13.7±2.2g/dl), (p<0.013). The preoperative median MPV levels were significantly lower in patients with PNET 7.8fL (7.2-9.4) than in patients with pancreatic adenocarcinomas 8.6fL (6.6-13.5), (p<0.014). In subgroup analysis, a significant difference in MPV levels was mainly caused by the difference between pancreatic adenocarcinomas and non-functional PNETs (p=0.017). The cut-off value of MPV level for detection of PNETs was calculated as≤7.8fL using ROC analysis [Sensitivity: 66.7%, specificity: 75.9%, AUC: 0.734 (0.587-0.880) p=0.022]. In logistic regression analysis, independent predictive factors for determining PNETs in the differential diagnosis of pancreatic adenocarcinomas were calculated as age (OR=0.068, 95% CI: 0.012-0.398), Ca 19-9 (OR=0.039, 95% CI: 0.006-0.263), MPV (OR=0.595, 95% CI: 0.243-1.458), and hemoglobin (OR=1.317, 95% CI: 0.831-2.086).

CONCLUSION

Age, Ca 19-9, MPV, and hemoglobin levels have diagnostic value for distinguishing PNETs from pancreatic adenocarcinomas.

Proteomics in pancreatic cancer research

Pancreatic cancer is a highly aggressive malignancy with a poor prognosis and deeply affects the life of people. Therefore, the earlier diagnosis and better treatments are urgently needed. In recent years, the proteomic technologies are well established and growing rapidly and have been widely applied in clinical applications, especially in pancreatic cancer research. In this paper, we attempt to discuss the development of current proteomic technologies and the application of proteomics to the field of pancreatic cancer research. This will explore the potential perspective in revealing pathogenesis, making the diagnosis earlier and treatment.

How useful is it clinically to analyse the K-ras mutational status for the diagnosis of exocrine pancreatic cancer? A systematic review and meta-analysis

BACKGROUND

More clinically meaningful diagnostic tests are needed in exocrine pancreatic cancer (EPC). K-ras mutations are the most frequently acquired genetic alteration in EPC. We analysed the diagnostic utility of detecting K-ras mutations through a systematic analysis of the literature.

METHODS

We searched PubMed using suitable medical subject headings and text words. Original research articles that evaluated the diagnostic accuracy of detecting K-ras mutations for diagnosis of EPC were selected. Two investigators independently extracted data from each study regarding the methodology used, the methodological quality of the study, the diagnostic accuracy reported and the authors' conclusions about clinical applicability of the test. Combined estimates for the sensitivity and specificity of K-ras were determined using bivariate meta-analysis; heterogeneity was explored using meta-regression.

RESULTS

We assessed 34 studies from 30 published articles. The research reports were prone to numerous methodological biases and often lacked vital information for assessing external validity. The sensitivity of detecting K-ras status ranged from 0% through 100%, and the specificity from 58% through 100%. Diagnostic accuracy was highest when cytohistological samples were used: sensitivity and specificity were 76·5% (66·7-84·2) and 91·8% (87·6-94·1), respectively. Studies conducted in a clinically relevant population observed lower accuracy than case-control designs (68·4% vs. 82·7%).

CONCLUSIONS

Because of the numerous methodological limitations of studies, the utility of analysing K-ras mutations for the diagnosis of EPC remains unknown. Flaws in diagnostic biomarkers with well-established biological properties, as K-ras, become even more relevant when the promises of 'personalized medicine' are pondered.

Construction of eukaryotic expression vectors expressing siRNAs targeting the HCCR2 gene and their transfection into PANC1 cells

AIM: To construct eukaryotic expression vectors expressing small interfering RNAs (siRNAs) targeting the human cervical cancer oncogene 2 (HCCR2) gene and transfect them into human pancreatic cancer cell line PANC1 to obtain a cell line stably transfected with the HCCR2 siRNA plasmid.

METHODS: Multiple siRNAs targeting the HCCR2 gene were designed, chemically synthesized, and cloned into the eukaryotic expression vector pGCsi-H1/Hygro/NEGative. The resulting recombinant vectors were identified by direct sequencing. After the recombinant pGCsi-HCCR plasmids were co-transfected with an HCCR eukaryotic expression vector into 293T cells, the protein expression of HCCR-2 was analyzed by Western blotting to identify the pGCsi-HCCR vector that had the highest gene knockdown efficiency. This recombinant vector was then transfected into PANC1 cells with LipofectamineTM 2000. G418-resistant clones were selected to obtain a stably transfected cell line. The expression of HCCR2 protein in stably transfected cell line was detected by Western blot.

RESULTS: The pGCsi-HCCR-3 plasmid had the highest gene knockdown efficiency and was used to transfect PANC1 cells. Western blotting analysis demonstrated that HCCR2 expression was significantly inhibited in PANC-1 cells stably transfected with the pGCsi-HCCR-3 plasmid compared to cells transfected with the empty vector.

CONCLUSION: Eukaryotic expression vectors expressing siRNAs targeting the HCCR2 gene were successfully constructed and a PANC-1 cell line stably transfected with the pGCsi-HCCR-3 plasmid was successfully established.

Study on chronic pancreatitis and pancreatic cancer using MRS and pancreatic juice samples

AIM: To investigate the markers of pancreatic diseases and provide basic data and experimental methods for the diagnosis of pancreatic diseases.

METHODS: There were 15 patients in the present study, among whom 10 had pancreatic cancer and 5, chronic pancreatitis. In all patients, pancreatic cancer or chronic pancreatitis was located on the head of the pancreas. Pathology data of all patients was confirmed by biopsy and surgery. Among the 10 patients with pancreatic cancer, 3 people had a medical history of long-term alcohol consumption. Of 5 patients with chronic pancreatitis, 4 men suffered from alcoholic chronic pancreatitis. Pancreatic juice samples were obtained from patients by endoscopic retrograde cholangio-pancreatography. Magnetic resonance spectroscopyn was performed on an 11.7-T scanner (Bruker DRX-500) using Call-Purcell-Meiboom-Gill pulse sequences. The parameters were as follows: spectral width, 15 KHz; time domain, 64 K; number of scans, 512; and acquisition time, 2.128 s.

RESULTS: The main component of pancreatic juice included leucine, iso-leucine, valine, lactate, alanine, acetate, aspartate, lysine, glycine, threonine, tyrosine, histidine, tryptophan, and phenylalanine. On performing 1D ¹H and 2D total correlation spectroscopy, we found a triplet peak at the chemical shift of 1.19 ppm, which only appeared in the spectra of pancreatic juice obtained from patients with alcoholic chronic pancreatitis. This triplet peak was considered the resonance of the methyl of ethoxy group, which may be associated with the metabolism of alcohol in the pancreas.

CONCLUSION: The triplet peak, at the chemical shift of 1.19 ppm is likely to be the characteristic metabolite of alcoholic chronic pancreatitis.

Acycloguanosyl 5'-thymidyltriphosphate, a thymidine analogue prodrug activated by telomerase, reduces pancreatic tumor growth in mice

BACKGROUND & AIMS

Gemcitabine is the standard of care for metastatic and nonresectable pancreatic tumors. Phase II and III trials have not demonstrated efficacy of recently developed reagents, compared with gemcitabine alone; new chemotherapic agents are needed. Ninety percent of pancreatic tumors have telomerase activity, and expression correlates with tumor stage. We developed a thymidine analogue prodrug, acycloguanosyl 5'-thymidyltriphosphate (ACV-TP-T), that is metabolized by telomerase and releases the active form of acyclovir. We investigated the antitumor efficacy of ACV-TP-T in vitro and in vivo.

METHODS

We evaluated proliferation and apoptosis of human pancreatic cancer cells (PANC-1, MiaPaca2, BxPc3, PL45, and Su.86.86) incubated with ACV-TP-T. The presence of ACV-TP-T and its metabolite inside the cells were analyzed by mass spectrometry. In vivo efficacy was evaluated in nude mice carrying PANC-1 or MiaPaca2 pancreatic xenograft tumors.

RESULTS

The prodrug of ACV-TP-T was actively metabolized inside pancreatic cancer cells into the activated form of acyclovir; proliferation was reduced, apoptosis was increased, and the cell cycle was altered in pancreatic cancer incubated with ACV-TP-T, compared with controls. Administration of ACV-TP-T to mice reduced growth, increased apoptosis, and reduced proliferation and vascularization of pancreatic xenograft tumors.

CONCLUSIONS

ACV-TP-T, a thymidine analogue that is metabolized by telomerase and releases the active form of acyclovir, reduces proliferation and induces apoptosis of human pancreatic cancer cell lines in vitro and pancreatic xenograft tumors in mice.

Elevated levels of CA 19-9 and CEA in pancreatic cancer-associated diabetes

BACKGROUND

The relationship between diabetes and pancreatic cancer has been established by more than several decades of research. However, serum levels of CEA and CA 19-9 in diabetic pancreatic cancer has not been shown.

METHODS

Preoperative serum levels of CEA and CA 19-9 and clinicopathological characteristics were retrospectively analyzed in 79 with or 229 without diabetes in pancreatic ductal adenocarcinoma (PDA) patients.

RESULTS

Of the 308 PDA patients enrolled, 79 (25.6%) patients had diabetes. The percentage of new-onset diabetes (i.e. <24 months in duration) was 57% (45/79) in PDA patients coupled with diabetes. Among diabetic PDA patients, mean total bilirubin and fasting blood glucose significantly increased in comparison with control groups (8.54 ± 14.88 vs. 4.16 ± 6.12; 170.22 ± 106.96 vs. 95.84 ± 15.76; P < 0.05). No significant differences were observed in mean levels of serum CA 19-9 and CEA levels between two groups. However, when the value of CEA and CA 19-9 was analyzed as a dichotomous variable, elevated CEA (≥5 ng/ml) and CA 19-9 (≥500 U/ml) levels were strongly correlated with the presence of diabetes in PDA patients.

CONCLUSION

Elevated CEA (≥5 ng/ml) and CA19-9 (≥500 U/ml) levels have an association with diabetic pancreatic cancer. New-onset diabetes combined with higher CA 19-9 and/or CEA might be regarded as a useful tool to screen early pancreatic cancer.

Mucins and pancreatic cancer

Pancreatic cancer is characterized by an often dramatic outcome (five year survival < 5%) related to a late diagnosis and a lack of efficient therapy. Therefore, clinicians desperately need new biomarkers and new therapeutic tools to develop new efficient therapies. Mucins belong to an ever increasing family of O-glycoproteins. Secreted mucins are the main component of mucus protecting the epithelia whereas membrane-bound mucins are thought to play important biological roles in cell-cell and cell-matrix interactions, in cell signaling and in modulating biological properties of cancer cells. In this review, we will focus on the altered expression pattern of mucins in pancreatic cancer, from the early neoplastic lesion Pancreatic Intraepithelial Neoplasia (PanIN) to invasive pancreatic carcinomas, and the molecular mechanisms (including genetic and epigenetic regulation) and signaling pathways known to control their expression. Moreover, we will discuss the recent advances about the biology of both secreted and membrane-bound mucins and their key roles in pancreatic carcinogenesis and resistance to therapy. Finally, we will discuss exciting opportunities that mucins offer as potential therapeutic targets in pancreatic cancer.

Reliable gene expression measurements from fine needle aspirates of pancreatic tumors: effect of amplicon length and quality assessment

BACKGROUND AND AIMS

Biomarker use for pancreatic cancer diagnosis has been impaired by a lack of samples suitable for reliable quantitative RT-PCR (qRT-PCR). Fine needle aspirates (FNAs) from pancreatic masses were studied to define potential causes of RNA degradation and develop methods for accurately measuring gene expression.

METHODS

Samples from 32 patients were studied. RNA degradation was assessed by using a multiplex PCR assay for varying lengths of glyceraldehyde-3-phosphate dehydrogenase, and effects on qRT-PCR were determined by using a 150-bp and a 80-bp amplicon for RPS6. Potential causes of and methods to circumvent RNA degradation were studied by using FNAs from a pancreatic cancer xenograft.

RESULTS

RNA extracted from pancreatic mass FNAs was extensively degraded. Fragmentation was related to needle bore diameter and could not be overcome by alterations in aspiration technique. Multiplex PCR for glyceraldehyde-3-phosphate dehydrogenase could distinguish samples that were suitable for qRT-PCR. The use of short PCR amplicons (<100 bp) provided reliable gene expression analysis from FNAs. When appropriate samples were used, the assay was highly reproducible for gene copy number with minimal (0.0003 or about 0.7% of total) variance.

CONCLUSIONS

The degraded properties of endoscopic FNAs markedly affect the accuracy of gene expression measurements. Our novel approach to designate specimens "informative" for qRT-PCR allowed accurate molecular assessment for the diagnosis of pancreatic diseases.

Marker expression in circulating cancer cells of pancreatic cancer patients

BACKGROUND

By the time patients are diagnosed with pancreatic cancer, circulating cancer cells probably exist. Therefore, the detection of pancreatic cancer cells in the peripheral circulation could be used to diagnose early pancreatic cancer, which would otherwise not be detected by current imaging methods.

METHODS

The expression levels of h-TERT, CK20, CEA, and C-MET were detected in a model of circulating micrometastasis in pancreatic cancer that were enriched using immune-magnetic separation of the circulating cancer cells. The sensitivity and specificity of the measurements were evaluated. The expression of the above genes was measured in the circulating cancer cells of pancreatic cancer patients. We compared their expression rate in pancreatic cancer patients at different stages to screen for the indicator with highest sensitivity and specificity for the detection of circulating pancreatic cancer cells.

RESULTS

Immuno-magnetic nanoparticles combined with RT-PCR enabled the detection of one tumor cell per 1×10(7) peripheral blood mononuclear cells. The positive expression rates of C-MET, h-TERT, CK20, and CEA in the pancreatic cancer group were 80% (20/25), 100% (25/25), 84% (21/25), and 80% (20/25), respectively, while in the benign disease control group the rates were 0% (0/15), 0% (0/15), 6.77% (1/15), and 0% (0/15), respectively. There was a significant difference in the positive expression rate between the two groups (P<0.05). The specificity of h-TERT, CEA, and C-MET was higher than that of CK20. The positive expression rate of the four genes was not related to gender, age, tumor size, CA 19-9, or CEA serum levels (P>0.05). However, the positive expression of C-MET, CK20, and CEA closely correlated with tumor stage (P<0.05). Immuno-magnetic nanoparticles combined with RT-PCR were specific and sensitive for the detection of circulating cancer cells.

CONCLUSIONS

The positive expression of C-MET, h-TERT, CK20, and CEA in the circulation of pancreatic patients could be used as an indicator for circulating cancer cells. The combined detection of the four genes improved the specificity and sensitivity to 100%, which may be attributable to the use of immuno-magnetic separation and enrichment of the circulating pancreatic cancer cells. Our results suggest the clinical utility of this approach.