Biomarkers in Diagnosis of pancreatic carcinoma in fine-needle aspirates

Reproducibility assessment of WHO reporting system for pancreaticobiliary cytopathology: A single institution experience

BACKGROUND

The World Health Organization (WHO) reporting system for pancreaticobiliary cytopathology was released to internationalize the reporting, assisting in correct diagnosis and patient treatment with significant revisions from the previous Papanicolaou Society of Cytopathology (PSC) system. The "neoplastic: benign" and "neoplastic: other" categories have mostly been superseded by two new ones: "pancreatic neoplasia-low-grade" (PaN-low) and "pancreatic neoplasia-high-grade" (PaN-high), which classify intermediate neoplastic lesions based on cytological atypia. We aim to assess the reproducibility and risk of malignancy (ROM) for reporting pancreaticobiliary cytopathology by the WHO system in comparison with the PSC system.

MATERIALS AND METHODS

A retrospective study by reviewing archival slides sent for pancreaticobiliary cytological evaluation from June 2021 to June 2023, by two pathologists blinded to each other's findings. Absolute ROM was determined by histopathology/cell block study/clinical follow-up (minimum 6 months)/overtly malignant imaging/metastasis.

RESULTS

A total of 332 cases from 329 patients met the inclusion criteria, comprising pancreatic, gallbladder, and biliary lesions. The median patient age was 54 years (range, 14-86 years). The overall sensitivity of the test is 74.9% specificity is 93.2%, positive predictive value of 96.8%, negative predictive value of 57.6%, and a diagnostic accuracy of 81.8%. The absolute ROM for each site in all categories was comparable with that of the published data from the WHO system.

CONCLUSION

Our study highlights the reliability of the WHO system for guiding clinical decision-making and patient management in the context of pancreaticobiliary. However, continual efforts among pathologists are essential to maintain consistent accuracy in cytological interpretations.

Clinical Significance of MUC4 and Associated Proteins in Pancreatic and Periampullary Cancers

OBJECTIVE

This study primarily aimed to assess the expression of MUC4 in patients with pancreatic ductal adenocarcinoma (PDAC) as compared with controls and assess its clinical relevance.

MATERIALS AND METHODS

Serum MUC4 levels and MUC4 gene expression in snap-frozen tissue were analyzed through surface plasmon resonance and quantitative polymerase chain reaction, respectively. Tumor tissues and control tissues were analyzed for MUC4 and other mucins through immunohistochemistry.

RESULT

MUC4 expression in tumor tissue was found to be significantly elevated in PDAC patients as compared with chronic pancreatitis tissues and normal pancreatic tissues. Periampullary carcinoma and cholangiocarcinoma tissue also showed increased expression of MUC4 and other mucins.

CONCLUSIONS

Differential expression of MUC4 in pancreatic tumor tissues can help to differentiate PDAC from benign conditions.

Earlier Diagnosis of Pancreatic Cancer: Is It Possible?

Pancreatic ductal adenocarcinoma has a very high mortality rate which has been only minimally improved in the last 30 years. This high mortality is closely related to late diagnosis, which is usually made when the tumor is large and has extensively infiltrated neighboring tissues or distant metastases are already present. This is a paradoxical situation for a tumor that requires nearly 15 years to develop since the first founding mutation. Response to chemotherapy under such late circumstances is poor, resistance is frequent, and prolongation of survival is almost negligible. Early surgery has been, and still is, the only approach with a slightly better outcome. Unfortunately, the relapse percentage after surgery is still very high. In fact, early surgery clearly requires early diagnosis. Despite all the advances in diagnostic methods, the available tools for improving these results are scarce. Serum tumor markers permit a late diagnosis, but their contribution to an improved therapeutic result is very limited. On the other hand, effective screening methods for high-risk populations have not been fully developed as yet. This paper discusses the difficulties of early diagnosis, evaluates whether the available diagnostic tools are adequate, and proposes some simple and not-so-simple measures to improve it.

Compliance with the Current NCCN Guidelines and Its Critical Role in Pancreatic Adenocarcinoma

OBJECTIVES

Since 2019, the National Comprehensive Cancer Network (NCCN) has recommended genetic testing for patients diagnosed with pancreatic adenocarcinoma that includes universal germline testing and tumor gene profiling for metastatic, locally advanced, or recurrent disease. However, testing compliance with this guideline has not yet been published in the English literature.

METHODS

A quality assurance/quality improvement retrospective review was done to identify patients diagnosed with pancreatic adenocarcinoma from January 2019 to February 2021 to include the patient's clinical status and genetic test results.

RESULTS

There were 20 patient cases identified with pancreatic adenocarcinoma. A total of 11 cases had molecular tumor gene profiling and microsatellite instability/mismatch repair (MSI/MMR) testing performed and 1 case had only MSI/MMR testing by immunohistochemistry performed. Only 3 patients of the 20 in total received germline testing.

CONCLUSION

There was a significant number of patients for whom tumor gene profiling or germline testing had never been attempted as per recommended NCCN guidelines.

Characterization of Mesothelin Glycosylation in Pancreatic Cancer: Decreased Core Fucosylated Glycoforms in Pancreatic Cancer Patients’ Sera

Currently, there are no reliable biomarkers for the diagnosis of pancreatic cancer (PaC). Glycoproteomic approaches that analyze the glycan determinants on specific glycoproteins have proven useful to develop more specific cancer biomarkers than the corresponding protein levels. In PaC, mesothelin (MSLN) is a neo-expressed glycoprotein. MSLN glycosylation has not been described and could be altered in PaC. In this work, we aimed to characterize MSLN glycans from PaC cells and serum samples to assess their potential usefulness as PaC biomarkers. First, we analyzed MSLN glycans from PaC cell lines and then we developed an enzyme-linked lectin assay to measure core fucosylated-MSLN (Cf-MSLN) glycoforms. MSLN glycans from PaC cells were analyzed by glycan sequencing and through Western blotting with lectins. All of the cell lines secreted MSLN, with its three N-glycosylation sites occupied by complex-type N-glycans, which were mainly α2,3-sialylated, core fucosylated and highly branched. The Cf-MSLN glycoforms were quantified on PaC serum samples, and compared with MSLN protein levels. The Cf-MSLN was significantly decreased in PaC patients compared to control sera, while no differences were detected by using MSLN protein levels. In conclusion, Cf-MSLN glycoforms were differently expressed in PaC, which opens the way to further investigate their usefulness as PaC biomarkers.

Tumor-Derived Exosomal RNA From Fine-Needle Aspiration Supernatant as a Novel Liquid Biopsy for Molecular Diagnosis of Cancer

Background: We hypothesized that the fine needle aspiration (FNA) supernatant from tumor might contain tumor-derived exosomes. The objective of this pilot study was to test if tumor-derived exosomal RNA could be found in FNA supernatants for molecular diagnosis of cancer.

Methods: 10 FNA samples from pancreatic tumor were included. After the routine recuperation of cellular material by centrifugation, the cell-free Cytolyt liquid was collected instead of being discarded. 10 ml Cytolyt was used to isolate the exosomes. Transmission electronic microscopy (TEM) was used to examine the presence of exosomes. The exosomal marker CD63 was analyzed by flow cytometry. The exosomal RNA was extracted. RT-qPCR was performed to detect the GAPDH and the tumor marker of glypican 1 gene expression.

Results: TEM confirmed the presence of exosomes from FNA supernatants. Flow cytometry showed a strong positive expression of exosome marker CD63. The concentration of exosomal RNA ranged from 18.81 to 354.75 ng/μl with an average of 81.76 ng/μl. The average exosomal RNA quantity was 1390.01 ng (range from 319.77 to 6030.75 ng) with an average 260/280 ratio of 2.12. GAPDH was detectable in all samples. Exosomal glypican 1 was detected in all samples of pancreatic ductal adenorcarcinomas (3/3) and absent from benign cystic samples (3/3). Furthermore, exosomal glypican 1 was positive in one sample with a non-contributive cytology and in one sample in which no malignant cell was found.

Conclusion: This is the first report that the supernatants from FNA biopsy may contain tumor-derived exosomal RNA. These tumor-derived exosomes from FNA may provide a new liquid biopsy for the molecular diagnosis of cancer.

Bioinformatic Analysis and Integration of Transcriptome and Proteome Results Identify Key Coding and Noncoding Genes Predicting Malignancy in Intraductal Papillary Mucinous Neoplasms of the Pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions of pancreatic ductal adenocarcinoma (PDAC). IPMNs are generally associated with high risk of developing malignancy and therefore need to be diagnosed and assessed accurately, once detected. Existing diagnostic methods are inadequate, and identification of efficient biomarker capable of detecting high-risk IPMNs is necessitated. Moreover, the mechanism of development of malignancy in IPMNs is also elusive.

METHODS

Gene expression meta-analysis conducted using 12 low-risk IPMN and 23 high-risk IPMN tissue samples. We have also listed all the altered miRNAs and long noncoding RNAs (lncRNAs), identified their target genes, and performed pathway analysis. We further enlisted cyst fluid proteins detected to be altered in high-risk or malignant IPMNs and compared them with fraction of differentially expressed genes secreted into cyst fluid.

RESULTS

Our meta-analysis identified 270 upregulated and 161 downregulated genes characteristically altered in high-risk IPMNs. We further identified 61 miRNAs and 14 lncRNAs and their target genes and key pathways contributing towards understanding of the gene regulation during the progression of the disease. Most importantly, we have detected 12 genes altered significantly both in cystic lesions and cyst fluid.

CONCLUSION

Our study reports, for the first time, a meta-analysis identifying key changes in gene expression between low-risk and high-risk IPMNs and also explains the regulatory aspect through construction of a miRNA-lncRNA-mRNA interaction network. The 12-gene-signature could function as potential biomarker in cyst fluid for detection of IPMN with a high risk of developing malignancy.

Fluorescent Biosensors Based on Silicon Nanowires

Nanostructures are arising as novel biosensing platforms promising to surpass current performance in terms of sensitivity, selectivity, and affordability of standard approaches. However, for several nanosensors, the material and synthesis used make the industrial transfer of such technologies complex. Silicon nanowires (NWs) are compatible with Si-based flat architecture fabrication and arise as a hopeful solution to couple their interesting physical properties and surface-to-volume ratio to an easy commercial transfer. Among all the transduction methods, fluorescent probes and sensors emerge as some of the most used approaches thanks to their easy data interpretation, measure affordability, and real-time in situ analysis. In fluorescent sensors, Si NWs are employed as substrate and coupled with several fluorophores, NWs can be used as quenchers in stem-loop configuration, and have recently been used for direct fluorescent sensing. In this review, an overview on fluorescent sensors based on Si NWs is presented, analyzing the literature of the field and highlighting the advantages and drawbacks for each strategy.

Magnetic detection of albuminuria using hematite nanorods synthesized via chemical hydrothermal method

Objectives

Albuminuria is a biomarker in the diagnosis of kidney disease which is due to the presence of high albumin in the urine and is one of the complications of diabetes. In recent years, the methods used to identify albuminuria have been expensive and time-consuming. Furthermore, another problem is the lack of accurate measurement of albuminuria. This problem leads to kidney isolation as well as a decrease in erythropoietin levels. Therefore, the main aim of our work is to design a magnetic nanobiosensor with better sensitivity to detect minimal levels of albuminuria.

Materials and Methods

In the present work, we synthesized Hematite Nano Rods (HNRs) using FeCl₃, NaOH and Cetyltrimethylammonium bromide (CTAB) precursors via the hydrothermal method. Then, HNRs were characterized using UV-vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometer (VSM) techniques.

Results

The obtained results from clinical performance of the HNR nanobiosensor show that the magnetization changes of HNR in interaction with the albumin biomarker can determine the presence or absence of protein in biological samples. The accuracy and repeatability of the HNR nanobiosensor from the value of the R2 coefficient in the standard equation is 0.9743.

Conclusion

We obtained the standard curve through interaction of the HNRs with albumin protein. The standard equation is obtained by plotting the magnetization curve of a non-interacting sample to interacting samples in terms of protein concentration. The Bland-Altman statistical graph prove that the HNR nanobiosensor is as reliable as experimental methods.

A Novel Silicon Platform for Selective Isolation, Quantification, and Molecular Analysis of Small Extracellular Vesicles

Introduction

Small extracellular vesicles (sEVs), thanks to their cargo, are involved in cellular communication and play important roles in cell proliferation, growth, differentiation, apoptosis, stemness and embryo development. Their contribution to human pathology has been widely demonstrated and they are emerging as strategic biomarkers of cancer, neurodegenerative and cardiovascular diseases, and as potential targets for therapeutic intervention. However, the use of sEVs for medical applications is still limited due to the selectivity and sensitivity limits of the commonly applied approaches.

Methods

Novel sensing solutions based on nanomaterials are arising as strategic tools able to surpass traditional sensor limits. Among these, Si nanowires (Si NWs), realized with cost-effective industrially compatible metal-assisted chemical etching, are perfect candidates for sEV detection.

Results

In this paper, the realization of a selective sensor able to isolate, concentrate and quantify specific vesicle populations, from minimal volumes of biofluid, is presented. In particular, this Si NW platform has a detection limit of about 2×10⁵ sEVs/mL and was tested with follicular fluid and blastocoel samples. Moreover, the possibility to detach the selectively isolated sEVs allowing further analyses with other approaches was demonstrated by SEM analysis and several PCRs performed on the RNA content of the detached sEVs.

Discussion

This platform overcomes the limit of detection of traditional methods and, most importantly, preserves the biological content of sEVs, opening the route toward a reliable liquid biopsy analysis.

Mesothelin is Commonly Expressed in Pancreatic Adenocarcinoma but Unrelated to Cancer Aggressiveness

Data on Mesothelin (MSLN) expression in human normal and cancerous tissues is controversial. We employed immunohistochemistry (IHC) on a tissue microarray (TMA) from 599 pancreatic cancers and 12 large tissue sections of pancreatitis. MSLN expression was highest in pancreatic adenocarcinomas (89%) and adenocarcinomas of the ampulla Vateri (79%), infrequent in pancreatitis and absent in 6 acinus cell carcinomas and normal pancreas. MSLN expression was unrelated to pathological tumor stage, grade, metastasis, and tumor-infiltrating CD8+ lymphocytes. In conclusion, pancreatic cancer may be ideally suited for putative anti- MSLN therapies, and MSLN may represent a suitable biomarker for pancreatic cancer diagnosis, especially on small biopsies.

Mesothelin Expression in Human Tumors: A Tissue Microarray Study on 12,679 Tumors

Mesothelin (MSLN) represents an attractive molecule for targeted cancer therapies. To identify tumors that might benefit from such therapies, tissue microarrays including 15,050 tumors from 122 different tumor types and 76 healthy organs were analyzed for MSLN expression by immunohistochemistry. Sixty-six (54%) tumor types showed at least occasional weak staining, including 50 (41%) tumor types with at least one strongly positive sample. Highest prevalence of MSLN positivity had ovarian carcinomas (serous 97%, clear cell 83%, endometrioid 77%, mucinous 71%, carcinosarcoma 65%), pancreatic adenocarcinoma (ductal 75%, ampullary 81%), endometrial carcinomas (clear cell 71%, serous 57%, carcinosarcoma 50%, endometrioid 45%), malignant mesothelioma (69%), and adenocarcinoma of the lung (55%). MSLN was rare in cancers of the breast (7% of 1138), kidney (7% of 807), thyroid gland (1% of 638), soft tissues (0.3% of 931), and prostate (0 of 481). High expression was linked to advanced pathological tumor (pT) stage (p < 0.0001) and metastasis (p < 0.0001) in 1619 colorectal adenocarcinomas, but unrelated to parameters of malignancy in 1072 breast-, 386 ovarian-, 174 lung-, 757 kidney-, 171 endometrial-, 373 gastric-, and 925 bladder carcinomas. In summary, numerous important cancer types with high-level MSLN expression might benefit from future anti-MSLN therapies, but MSLN’s prognostic relevance appears to be limited.

Biosensing platforms based on silicon nanostructures: A critical review

Biosensors are revolutionizing the health-care systems worldwide, permitting to survey several diseases, even at their early stage, by using different biomolecules such as proteins, DNA, and other biomarkers. However, these sensing approaches are still scarcely diffused outside the specialized medical and research facilities. Silicon is the undiscussed leader of the whole microelectronics industry, and novel sensors based on this material may completely change the health-care scenario. In this review, we will show how novel sensing platforms based on Si nanostructures may have a disruptive impact on applications with a real commercial transfer. A critical study for the main Si-based biosensors is herein presented with a comparison of their advantages and drawbacks. The most appealing sensing devices are discussed, starting from electronic transducers, with Si nanowires field-effect transistor (FET) and porous Si, to their optical alternatives, such as effective optical thickness porous silicon, photonic crystals, luminescent Si quantum dots, and finally luminescent Si NWs. All these sensors are investigated in terms of working principle, sensitivity, and selectivity with a specific focus on the possibility of their industrial transfer, and which ones may be preferred for a medical device.

Quantitative assessment of the diagnostic role of mucin family members in pancreatic cancer: a meta-analysis

Background

The use of mucins (MUC) as specific biomarkers for various malignancies has recently emerged. MUC1, MUC4, MUC5AC, and MUC16 can be detected at different stages of pancreatic cancer (PC), and can be valuable for indicating the initiation and progression of this disease. However, the diagnostic significance of the mucin family in patients with PC remains disputed. Herein, we assessed the diagnostic accuracy of mucins in PC using a meta-analysis.

Methods

We searched the PubMed, Cochrane Library, Institute for Scientific Information (ISI) Web of Science, Embase, and Chinese databases from their date of inception to June 1, 2020 to identify studies assessing the diagnostic performance of mucins in PC. The estimations of diagnostic indicators in selected studies were extracted for further analysis by Meta-DiSc software. Publication bias was assessed using Deeks’ funnel plot asymmetry test.

Results

Our meta-analysis included 34 studies. The pooled accuracy indicators of MUC1 in PC including the sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) (with 95% confidence intervals) were 0.84 (0.82–0.86), 0.60 (0.56–0.64), 18.37 (9.18–36.78), 2.62 (1.79–3.86), and 0.22 (0.15–0.33), respectively. The area under the summary receiver operating characteristic (SROC) curve was 0.8875 and the Q index was 0.8181. Quantitative random-effects meta-analysis of MUC4 in PC using the summary (ROC) curve model revealed a pooled sensitivity of 0.86 (95% confidence interval, 0.82–0.89) and specificity of 0.88 (95% confidence interval, 0.85–0.91). In addition, the meta-analysis of MUC5AC in PC diagnosis also showed a high sensitivity and specificity of 0.71 (95% confidence interval, 0.65–0.76) and 0.60 (95% confidence interval, 0.53–0.66), respectively. Regarding MUC16, the area under the summary ROC curve and Q index were 0.9185 and 0.8516, respectively.

Conclusions

In summary, our results suggested a good diagnostic accuracy of several crucial mucins in PC. Mucins may serve as optional indicators in PC examination, and further research is warranted to investigate the role of mucins as potential clinical biomarkers.

MUC Glycoproteins: Potential Biomarkers and Molecular Targets for Cancer Therapy

MUC proteins have great significance as prognostic and diagnostic markers as well as a potential target for therapeutic interventions in most cancers of glandular epithelial origin. These are high molecular weight glycosylated proteins located in the epithelial lining of several tissues and ducts. Mucins belong to a heterogeneous group of large O-glycoproteins that can be either secreted or membrane-bound. Glycosylation, a post-translational modification affects the biophysical, functional and biochemical properties and provides structural complexity for these proteins. Aberrant expression and glycosylation of mucins contribute to tumour survival and proliferation in many cancers, which in turn activates numerous signalling pathways such as NF-kB, ERα, HIF, MAPK, p53, c-Src, Wnt and JAK-STAT, etc. This subsequently induces cancer cell growth, proliferation and metastasis. The present review mainly demonstrates the functional aspects of MUC glycoproteins along with its unique signalling mechanism and role of aberrant glycosylation in cancer progression and therapeutics. The importance of MUC proteins and its subtypes in a wide spectrum of cancers including but not limited to breast cancer, colorectal cancer, endometrial and cervical cancer, lung cancer, primary liver cancer, pancreatic cancer, prostate cancer and ovarian cancer has been exemplified with significance in targeting the same. Several patents associated with the MUC proteins in the field of cancer therapy are also emphasized in the current review.

Overexpression of Mesothelin in Pancreatic Ductal Adenocarcinoma (PDAC)

Purpose: Pancreatic ductal adenocarcinoma (PDAC) with difficulty in early diagnosis does not respond well to conventional treatments and has not occurred significant improvement in the overall 5-year survival rates. Mesothelin (MSLN) is a tumor differentiation antigen expressed in several solid neoplasms and a limited number of healthy tissues. Its selective expression on malignant cells makes it an interesting candidate for investigation as a diagnostic and prognostic biomarker and as a therapeutic target. In this study, we detected the expression of MSLN in PDAC and analyzed the correlation between the expression of MSLN and clinicopathological data, so as to provide more theoretical basis for the role of MSLN in the diagnosis and treatment of PDAC. Patients and methods: Cancer and para-cancer tissues of 24 cases with PDAC were assessed by standardized immunohistochemical (IHC) detection with two kinds of anti-MSLN antibodies (EPR4509 and EPR19025-42) to detect their positive expression rates and study the correlation between the expression of MSLN and the clinicopathological data. Results: The two anti-MSLN antibodies of cancer tissues showed positive expression with tan yellow or tan brown granules diffusely distributed on the cell membrane in 22 of 24 cases with PDAC (positive rate of 91.67%), and the positive expression of the two antibodies EPR4509 and EPR19025-42 was completely consistent in all tissue samples. No expression of the two anti-MSLN antibodies was found in para-cancer tissues and the difference was statistically significant (χ2=40.615, p=0.000, p<0.05) when compared with PDAC tissues. There was no significant correlation between MSLN expression and clinicopathological data, such as gender, tumor size, location, pathological stage, differentiation degree and lymph node metastasis (p>0.05). Conclusion: MSLN was highly expressed in PDAC tissues, but not in paracancerous tissues. There was no significant correlation between MSLN expression and clinicopathological factors. The overexpression of MSLN may have promising prospects in diagnosis, targeted therapy and immunotherapy of PDAC.

Biosensors for early diagnosis of pancreatic cancer: a review

Pancreatic cancer is characterized by extremely high mortality and poor prognosis and is projected to be the leading cause of cancer deaths by 2030. Due to the lack of early symptoms and appropriate methods to detect pancreatic carcinoma at an early stage as well as its aggressive progression, the disease is often quite advanced by the time a definite diagnosis is established. The 5-year relative survival rate for all stages is approximately 8%. Therefore, detection of pancreatic cancer at an early surgically resectable stage is the key to decrease mortality and to improve survival. The traditional methods for diagnosing pancreatic cancer involve an imaging test, such as ultrasound or magnetic resonance imaging, paired with a biopsy of the mass in question. These methods are often expensive, time consuming, and require trained professionals to use the instruments and analyze the imaging. To overcome these issues, biosensors have been proposed as a promising tool for the early diagnosis of pancreatic cancer. The present review critically discusses the latest developments in biosensors for the early diagnosis of pancreatic cancer. Protein and microRNA biomarkers of pancreatic cancer and corresponding biosensors for pancreatic cancer diagnosis have been reviewed, and all these cases demonstrate that the emerging biosensors are becoming an increasingly relevant alternative to traditional techniques. In addition, we discuss the existing problems in biosensors and future challenges.

The Role of Mesothelin as a Diagnostic and Therapeutic Target in Pancreatic Ductal Adenocarcinoma: A Comprehensive Review

Mesothelin is a tumor differentiation antigen, which is highly expressed in several solid neoplasms, including pancreatic cancer. Its selective expression on malignant cells and on only a limited number of healthy tissues has made it an interesting candidate for investigation as a diagnostic and prognostic biomarker and as a therapeutic target. Based on a strong preclinical rationale, a number of therapeutic agents targeting mesothelin have entered clinical trials, including immunotoxins, monoclonal antibodies, antibody-drug conjugates, cancer vaccines, and adoptive T cell therapies with chimeric antigen receptors. In pancreatic cancer, mesothelin has been investigated mainly to address two unmet issues: the urgent need for new laboratory techniques for early tumor detection and the lack of successfully targetable oncogenic alterations for patients' treatment. In this review, we describe the clinicopathological significance of mesothelin expression in pancreatic cancer initiation and progression, we summarize available studies evaluating mesothelin as a potential diagnostic and prognostic biomarker in this disease, and we discuss current evidence and future perspectives of preclinical and clinical studies testing mesothelin as a molecular target for pancreatic cancer treatment.

Ancillary Techniques in Cytologic Specimens Obtained from Solid Lesions of the Pancreas: A Review

Advanced methods of molecular characterization have elucidated the genetic, epigenetic, and proteomic alterations associated with the broad spectrum of pancreatic disease, particularly neoplasia. Next-generation sequencing, in particular, has revealed the genomic diversity among pancreatic ductal adenocarcinoma, neuroendocrine and acinar tumors, solid pseudopapillary neoplasm, and other pancreatico-biliary neoplasms. Differentiating these entities from one another by morphologic analysis alone may be challenging, especially when examining the small quantities of diagnostic material inherent to cytologic specimens. In order to enhance the sensitivity and specificity of pancreatic cytomorphology, multiple diagnostic, prognostic, and predictive ancillary tests have been and continue to be developed. Although a great number of such tests have been developed for evaluation of specimens collected from cystic lesions and strictures, ancillary techniques also play a significant role in the evaluation of cytologic specimens obtained from solid lesions of the pancreas. Furthermore, while some tests have been developed to differentiate diagnostic entities from one another, others have been developed to simply identify dysplasia and malignancy. Ancillary studies are particularly important in the subset of cases for which cytomorphologic analysis provides a result that is equivocal or insufficient to guide clinical management. Selection of appropriate ancillary testing modalities requires familiarity with both their methodology and the molecular basis of the pancreatic diseases for which testing is being performed.

Rationale and feasibility of mucin expression profiling by qRT-PCR as diagnostic biomarkers in cytology specimens of pancreatic cancer

BACKGROUND

Aberrantly expressed mucin glycoproteins (MUC) play important roles in pancreatic ductal adenocarcinoma (PDAC), yet their use as a diagnostic aid in fine-needle aspiration biopsy (FNAB) is poorly documented. The aim of this study was to investigate the rationale and feasibility of mucin (MUC1, MUC2, MUC3, MUC4, MUC5AC, and MUC6) expression profiling by RT-PCR for diagnostic applications in cytology.

METHODS

Mucin expression was examined by RT-PCR and immunohistochemistry in specimens resected from patients with pancreatic (n = 101), ampullary (n = 23), and common bile duct (n = 10) cancers and 33 with chronic pancreatitis. Furthermore, mucin profiling by RT-PCR was prospectively compared in surgical and biopsy specimens of 40 patients with pancreatic solid tumours qualified for FNAB prior to surgery.

RESULTS

A logistic regression model to distinguish PDAC from chronic pancreatitis using RT-PCR profiling included MUC3, MUC5AC, and MUC6. The same set of mucins differentiated ampullary and bile duct cancers from chronic pancreatitis. AUCs for the ROC curves derived from the two models were 0.95 (95%CI 0.87-0.99) and 0.92 (95%CI 0.81-0.98), respectively. The corresponding positive likelihood ratios were 6.02 and 5.97, while the negative likelihood ratios were 0.10 and 0.12. AUCs of ROC curves obtained by RT-PCR and immunohistochemistry demonstrated that both analytical methods were comparable. Surgical and cytological samples showed significantly correlated values of ΔCt for individual mucins with the overall Pearson's correlation coefficient r = 0.841 (P = 0.001).

CONCLUSIONS

Mucin expression profiling of pancreatic cancer with RT-PCR is feasible and may be a valuable help in discriminating malignant lesions from chronic pancreatitis in FNAB cytology.

A quarter century of EUS-FNA: Progress, milestones, and future directions

Tissue acquisition using EUS has considerably evolved since the first EUS-FNA was reported 25 years ago. Its introduction was an important breakthrough in the endoscopic field. EUS-FNA has now become a part of the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of the organs in its proximity, including lung diseases. This review aims to present the history of EUS-FNA development and to provide a perspective on the recent developments in procedural techniques and needle technologies that have significantly extended the role of EUS and its clinical applications. There is a bright future ahead for EUS-FNA in the years to come as extensive research is conducted in this field and various technologies are continuously implemented into clinical practice.

Differences in MUC4 Expression in Pancreatic Cancers and Pancreatic Cysts in Egypt

Pancreatic cancer is the fourth cause of cancer deaths in the U.S. with most patients diagnosed at advanced stages followed by short survival. Therefore, biomarkers for early detection are urgently needed. Mucin 4 (MUC4) is a mucin protein encoded by the MUC4 gene and identified in the majority of pancreatic cancers. With increasing clinical identification and diagnosis of pancreatic cysts globally and transformation of some cysts into pancreatic cancer, it is important to evaluate if MUC4 is expressed in pancreatic cysts.

Immunohistochemistry assays utilizing heat-induced epitope retrieval (HIER) were performed to examine MUC4 protein expression in 44 paraffin-embedded tissues of pancreatic cancers and 20 pancreatic cysts. All patients were diagnosed and operated upon at the Mansoura University Gastrointestinal Surgery Center in Egypt. Clinical, demographic, and survival information were abstracted from the patients’ medical records. Logistic regression was performed to predict expression of MUC4 protein in cancer and cysts, by type of cysts.

Pancreatic cyst patients were significantly younger than pancreatic cancer patients (Mean age of 28.7 ± 5.25 vs. 54.84 ± 10.60 years) (p=0.0001). Expression of MUC4 was not different between cancers and pancreatic cysts (p=0.16). However, type of pancreatic cysts was predictive of MUC4 expression. Mucinous cystic neoplasms and serous cystadenoma cysts showed significantly higher MUC4 expression than non-specified and pseudocysts (80%, 75%, 25%, and 0% expression for the 4 types of cysts, respectively) (p=0.022).

MUC4 expression may be associated with certain types of cysts. Follow-up of pancreatic cyst patients who show MUC4 expression might reveal clues to early detection of pancreatic cancer.

NIDO, AMOP and vWD domains of MUC4 play synergic role in MUC4 mediated signaling

MUC4 mucin is well known as an important potential target to overcome pancreatic cancer. Three unique domains (NIDO, AMOP, and vWD) with unclear roles only present in MUC4 but are not found in other membrane-bound mucins. Our previous studies first reported that its splice variant, MUC4/Y can be a model of MUC4 (MUC4 gene fragment is more than 30KB, too huge to clone and eukaryotic express) in pancreatic cancer. More importantly, based on MUC4/Y with the appropriate length of gene sequence, it is easy to construct the unique domain-lacking models of MUC4/Y (MUC4) for research. The present study focuses on investigation of the respective role of the unique NIDO, AMOP, and vWD domain or their synergistic effect on MUC4(MUC4/Y)-mediated functions and mechanisms by series of in vitro assays, sequence-based transcriptome analysis, validation of qRT-PCR & Western blot, and systematic comparative analysis. Our results demonstrate: 1) NIDO, AMOP, and vWD domain or their synergy play significant roles on MUC4/Y-mediated malignant function of pancreatic cancer, downstream of molecule mechanisms, particularly MUC4/Y-triggered malignancy-related positive feedback loops, respectively. 2) The synergistic roles of three unique domains on MUC4/Y-mediated functions and mechanisms are more prominent than the respective domain because the synergy of three domain plays the more remarkable effects on MUC4/Y-mediated signaling hub. Thus, to improve reversed effects of domain-lacking and break the synergism of domains will contribute to block MUC4/Y(MUC4) triggering various oncogenic signaling pathways.

Retrospective screening of microarray data to identify candidate IFN-inducible genes in a HTLV-1 transformed model

HuT-102 cells are considered one of the most representable human T-lymphotropic virus 1 (HTLV-1)-infected cell lines for studying adult T-cell lymphoma (ATL). In our previous studies, genome-wide screening was performed using the GeneChip system with Human Genome Array U133 Plus 2.0 for transforming growth factor-β-activated kinase 1 (TAK1)-, interferon regulatory factor 3 (IRF3)- and IRF4-regulated genes to demonstrate the effects of interferon-inducible genes in HuT-102 cells. Our previous findings demonstrated that TAK1 induced interferon inducible genes via an IRF3-dependent pathway and that IRF4 has a counteracting effect. As our previous data was performed by manual selection of common interferon-related genes mentioned in the literature, there has been some obscure genes that have not been considered. In an attempt to maximize the outcome of those microarrays, the present study reanalyzed the data collected in previous studies through a set of computational rules implemented using ‘R’ software, to identify important candidate genes that have been missed in the previous two studies. The final list obtained consisted of ten genes that are highly recommend as potential candidate for therapies targeting the HTLV-1 infected cancer cells. Those genes are ATM, CFTR, MUC4, PARP14, QK1, UBR2, CLEC7A (Dectin-1), L3MBTL, SEC24D and TMEM140. Notably, PARP14 has gained increased attention as a promising target in cancer cells.

Mucins: Structural diversity, biosynthesis, its role in pathogenesis and as possible therapeutic targets

Mucins are the main structural components of mucus that create a selective protective barrier for epithelial surface and also execute wide range of other physiological functions. Mucins can be classified into two types, namely secreted mucins and membrane bounded mucins. Alterations in mucin expression or glycosylation and mislocalization have been seen in various types of pathological conditions such as cancers, inflammatory bowel disease and ocular disease, which highlight the importance of mucin in maintaining homeostasis. Hence mucins can be used as attractive target for therapeutic intervention. In this review, we discuss in detail about the structural diversity of mucins; their biosynthesis; its role in pathogenesis; regulation and as possible therapeutic targets.

Pancreatic cancer and associated exosomes

Pancreatic cancers with poor prognosis are highly malignant, readily metastatic and of immune tolerance, mainly due to delayed detection. The metastatic progression and immune tolerance of pancreatic cancer is greatly attributed to the intercellular communication. However, exosomes are deemed to be the most important tool of intercellular communicators. Thus, we present a review of pancreatic cancer and exosomes in this article. We intensively summarize the progress of early pancreatic cancer and the relationship of the proliferation, progression and metastasis of pancreatic cancer and pancreatic cancer-derived exosomes, and propose new ideas of the study of pancreatic cancer.

MUC4 mucin- a therapeutic target for pancreatic ductal adenocarcinoma

INTRODUCTION

Pancreatic cancer (PC) is characterized by mucin overexpression. MUC4 is the most differentially overexpressed membrane-bound mucin that plays a functional role in disease progression and therapy resistance. Area covered: We describe the clinicopathological significance of MUC4, summarize mechanisms contributing to its deregulated expression, review preclinical studies aimed at inhibiting MUC4, and discuss how MUC4 overexpression provides opportunities for developing targeted therapies. Finally, we discuss the challenges for developing MUC4-based therapeutics, and identify areas where efforts should be directed to effectively exploit MUC4 as a therapeutic target for PC. Expert opinion: Studies demonstrating that abrogation of MUC4 expression reduces proliferation and metastasis of PC cells and enhances sensitivity to therapeutic agents affirm its utility as a therapeutic target. Emerging evidence also supports the suitability of MUC4 as a potential immunotherapy target. However, these studies have been limited to in vitro, ex vivo or in vivo approaches using xenograft tumors in immunodeficient murine models. For translational relevance, MUC4-targeted therapies should be evaluated in murine models with intact immune system and accurate tumor microenvironment. Additionally, future studies evaluating MUC4 as a target for immunotherapy must entail characterization of immune response in PC patients and investigate its association with immunosuppression and survival.

Effects of RNAi-mediated MUC4 gene silencing on the proliferation and migration of human pancreatic carcinoma BxPC-3 cells

It was previously demonstrated that mucin 4 (MUC4) is not expressed in normal pancreatic tissues or in chronic pancreatitis tissue but is highly expressed in pancreatic cancer (PC) tissue. Effective MUC4 gene knockdown in PC may contribute to the elucidation of pancreatic tumor development and metastasis, and may be valuable in new therapeutic approaches. Thus to confirm this, in the present study, the BxPC-3 cell line was transfected with eight pairs of shRNA lentiviral vectors for MUC4. The qPCR results showed that expression of MUC4 mRNA in the BxPC-3 cells was significantly decreased at 96 h after transfection. One of these shRNA lentiviral vectors (shRNA‑A141) had showed the strongest suppressive effect on MUC4 mRNA expression and was used for MUC4 knockdown in BxPC-3 cells. After stable transfection, BxPC-3 cells showed a significantly lower expression of MUC4 mRNA and MUC4 protein, and were suppressed on cell growth and migration. In vivo, lower tumor growth rates and tumor volume were observed in the tumors derived from the MUC4-knockdown cells, whereas the transplanted tumors derived from the control group cells, grew rapidly. Thus, inhibition of MUC4 expression may be an effective means for mitigating metastasis and invasion of PC.

Semiquantitative immunohistochemistry for mucin (MUC1, MUC2, MUC3, MUC4, MUC5AC, and MUC6) profiling of pancreatic ductal cell adenocarcinoma improves diagnostic and prognostic performance

AIMS

Mucin (MUC) glycoproteins are involved in various steps of the carcinogenesis and progression of human malignancies. The aim of this study was to verify whether semiquantitative evaluation of MUC staining by immunohistochemistry may help to differentiate pancreatic ductal cell adenocarcinoma (PDAC) from chronic pancreatitis and normal pancreas.

METHODS AND RESULTS

Mucin expression was examined by immunohistochemistry in surgical specimens resected from 101 patients with PDAC and 33 with chronic pancreatitis, and in 40 normal pancreatic tissue specimens. A quickscore (QS, range 0-300) was calculated by multiplying staining intensity by the percentage of positive cells. A diagnostic model was developed for MUC QS (MUC1, MUC2, MUC3, MUC4, MUC5AC, and MUC6), based on a receiver operating characteristic (ROC) curve and logistic regression analysis. Median QS values for MUC1 and MUC5AC were significantly higher for PDAC, whereas patients with non-malignant tissues had higher values for MUC3 and MUC6. The area under the curve for the ROC curve derived from the diagnostic model including MUC3, MUC5AC and MUC6 was 0.96 [95% confidence interval (CI) 0.91-0.98], with 85% sensitivity and 94% specificity. Median QS values for MUC2 were significantly higher in patients with less advanced tumours, whereas venous invasion was associated with a lower QS for MUC6. Moreover, multivariate survival analysis revealed that low MUC6 expression was a negative prognostic factor, with a hazard ratio of 1.73 (95% CI 1.07-2.81).

CONCLUSIONS

The three-MUC diagnostic model (MUC3, MUC5AC, and MUC6) showed an excellent ability to discriminate pancreatic cancer from non-malignant tissues, and yielded information that may prove useful for the development of clinical applications.

Diagnostic value of IMP3 and mesothelin in differentiating pancreatic ductal adenocarcinoma from chronic pancreatitis

BACKGROUND

The discrimination between pancreatic ductal adenocarcinoma (PDA) and chronic pancreatitis may be confusing at both clinical and radiologic levels. So, the search for biomarkers able to distinguish both clinical conditions is of great interest.

AIM

This study was undertaken to assess the value of insulin-like growth factor II mRNA binding protein 3 (IMP3) and mesothelin to differentiate PDA from non-neoplastic/reactive pancreatic duct epithelium.

METHODS

Immunohistochemical staining for IMP3 and mesothelin was performed on 40 formalin-fixed, paraffin-embedded tissue sections of PDA, 20 biopsies of chronic pancreatitis and 10 normal pancreatic tissue obtained from tumor-free surgical margins. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were calculated.

RESULTS

IMP3 immunoreactivity was observed in 34 of 40 (85%) cases of PDA. The staining reaction was moderate to strong in 30 (75%) cases and diffuse in 26 (65%) cases. Eighteen of 20 (90%) biopsies of chronic pancreatitis were negative for IMP3, while the other two cases (10%) showed weak and focal IMP3 immunoreactivity. On the other hand, mesothelin demonstrated positive immunoreactivity in 30 of 40 (75%) cases of PDA. The staining reaction was moderate to strong in 24 (60%) cases and diffuse in 22 (55%) cases. Sixteen of 20 (80%) biopsies of chronic pancreatitis were negative for mesothelin, while weak and focal mesothelin staining was detected in the other 4 cases. All normal pancreatic tissues were negative for IMP3 and mesothelin expression. IMP3 showed higher sensitivity (85%) and specificity (90%) than mesothelin (75% and 80%, respectively).

CONCLUSIONS

Our results showed that IMP3 immunostaining has a higher sensitivity and specificity than mesothelin for the diagnosis of PDA. IMP3 and mesothelin may be useful markers in distinguishing neoplastic from reactive lesions of the pancreas in instances where this is impossible by morphology alone in surgical pathology practice.

Difficult Diagnostic Problems in Pancreatobiliary Neoplasia

CONTEXT

Many common diagnostic dilemmas are encountered in pancreatobiliary pathology, frequently resulting in uncertainty on behalf of the pathologist and referral for a second opinion.

OBJECTIVES

To review 4 common diagnostic dilemmas encountered in the practice of pancreatobiliary pathology: (1) pancreatic ductal adenocarcinoma versus chronic pancreatitis; (2) pancreatic ductal carcinoma versus adenocarcinomas arising in the ampulla and intrapancreatic common bile duct; (3) the distinction of uncommon intraductal neoplasms--intraductal oncocytic papillary neoplasm, intraductal tubulopapillary neoplasm, and intraductal acinar cell carcinoma; and (4) intrahepatic cholangiocarcinoma versus metastatic carcinoma.

DATA SOURCES

A review of pertinent literature, along with the authors' personal experience, based on institutional and consultation materials.

CONCLUSIONS

Important diagnostic features for a few challenging problems in pancreatobiliary pathology are reviewed. Careful study of the microscopic features along with awareness of differential diagnoses and diagnostic pitfalls generally allows distinction of these entities. We also highlight established and novel ancillary studies that help to arrive at an accurate diagnosis.

Specific-detection of clinical samples, systematic functional investigations, and transcriptome analysis reveals that splice variant MUC4/Y contributes to the malignant progression of pancreatic cancer by triggering malignancy-related positive feedback loops signaling

Background

MUC4 plays important roles in the malignant progression of human pancreatic cancer. But the huge length of MUC4 gene fragment restricts its functional and mechanism research. As one of its splice variants, MUC4/Y with coding sequence is most similar to that of the full-length MUC4 (FL-MUC4), together with alternative splicing of the MUC4 transcript has been observed in pancreatic carcinomas but not in normal pancreas. So we speculated that MUC4/Y might be involved in malignant progression similarly to FL-MUC4, and as a research model of MUC4 in pancreatic cancer. The conjecture was confirmed in the present study.

Methods

MUC4/Y expression was detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) using gene-specific probe in the clinic samples. The effects of MUC4/Y were observed by serial in vitro and in vivo experiments based on stable over-expressed cell model. The underlying mechanisms were investigated by sequence-based transcriptome analysis and verified by qRT-PCR, Western blot and enzyme-linked immunosorbent assays.

Results

The detection of clinical samples indicates that MUC4/Y is significantly positive-correlated with tumor invasion and distant metastases. Based on stable forced-expressed pancreatic cancer PANC-1 cell model, functional studies show that MUC4/Y enhances malignant activity in vitro and in vivo, including proliferation under low-nutritional-pressure, resistance to apoptosis, motility, invasiveness, angiogenesis, and distant metastasis. Mechanism studies indicate the novel finding that MUC4/Y triggers malignancy-related positive feedback loops for concomitantly up-regulating the expression of survival factors to resist adverse microenvironment and increasing the expression of an array of cytokines and adhesion molecules to affect the tumor milieu.

Conclusions

In light of the enormity of the potential regulatory circuitry in cancer afforded by MUC4 and/or MUC4/Y, repressing MUC4 transcription, inhibiting post-transcriptional regulation, including alternative splicing, or blocking various pathways simultaneously may be helpful for controlling malignant progression. MUC4/Y- expression model is proven to a valuable tool for the further dissection of MUC4-mediated functions and mechanisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0309-8) contains supplementary material, which is available to authorized users.

Spatiotemporal proteomic analyses during pancreas cancer progression identifies serine/threonine stress kinase 4 (STK4) as a novel candidate biomarker for early stage disease

Pancreas cancer, or pancreatic ductal adenocarcinoma, is the deadliest of solid tumors, with a five-year survival rate of <5%. Detection of resectable disease improves survival rates, but access to tissue and other biospecimens that could be used to develop early detection markers is confounded by the insidious nature of pancreas cancer. Mouse models that accurately recapitulate the human condition allow disease tracking from inception to invasion and can therefore be useful for studying early disease stages in which surgical resection is possible. Using a highly faithful mouse model of pancreas cancer in conjunction with a high-density antibody microarray containing ∼2500 antibodies, we interrogated the pancreatic tissue proteome at preinvasive and invasive stages of disease. The goal was to discover early stage tissue markers of pancreas cancer and follow them through histologically defined stages of disease using cohorts of mice lacking overt clinical signs and symptoms and those with end-stage metastatic disease, respectively. A panel of seven up-regulated proteins distinguishing pancreas cancer from normal pancreas was validated, and their levels were assessed in tissues collected at preinvasive, early invasive, and moribund stages of disease. Six of the seven markers also differentiated pancreas cancer from an experimental model of chronic pancreatitis. The levels of serine/threonine stress kinase 4 (STK4) increased between preinvasive and invasive stages, suggesting its potential as a tissue biomarker, and perhaps its involvement in progression from precursor pancreatic intraepithelial neoplasia to pancreatic ductal adenocarcinoma. Immunohistochemistry of STK4 at different stages of disease revealed a dynamic expression pattern further implicating it in early tumorigenic events. Immunohistochemistry of a panel of human pancreas cancers confirmed that STK4 levels were increased in tumor epithelia relative to normal tissue. Overall, this integrated approach yielded several tissue markers that could serve as signatures of disease stage, including early (resectable), and therefore clinically meaningful, stages.

Mesothelin expression in pancreatic mucinous cysts

OBJECTIVES

Mesothelin (MSLN) is a differentiation antigen found to be overexpressed in intraductal papillary mucinous neoplasms (IPMNs) and is a potential treatment target in pancreatic ductal adenocarcinoma.

METHODS

From institutional archives, 114 cases of resected pancreatic mucinous cysts were identified, including IPMN and mucinous cystic neoplasm (MCN). Immunohistochemical analysis of MSLN was performed on representative sections.

RESULTS

MSLN was seen more frequently in neoplastic epithelial cells from IPMN (39/52; P < .0005) and MCN (9/14; P < .0001) compared with unremarkable adjacent pancreatic and bile ducts (0/57) and benign foveolar and duodenal epithelium (0/21). When present, MSLN was diffusely expressed in neoplastic epithelium and only focally expressed in adjacent ducts (8/57). No significant difference was seen (P = .26) in MLSN expression between IPMN (79%) and MCN (83%) when only presence or absence was considered.

CONCLUSION

Our findings suggest that MLSN can be used as a marker of neoplastic transformation of epithelial cells in pancreatic mucinous cysts. The findings can help identify neoplastic mucinous epithelium.

Expression of KOC, S100P, mesothelin and MUC1 in pancreatico-biliary adenocarcinomas: development and utility of a potential diagnostic immunohistochemistry panel

BACKGROUND

Pancreatico-biliary adenocarcinomas (PBA) have a poor prognosis. Diagnosis is usually achieved by imaging and/or endoscopy with confirmatory cytology. Cytological interpretation can be difficult especially in the setting of chronic pancreatitis/cholangitis. Immunohistochemistry (IHC) biomarkers could act as an adjunct to cytology to improve the diagnosis. Thus, we performed a meta-analysis and selected KOC, S100P, mesothelin and MUC1 for further validation in PBA resection specimens.

METHODS

Tissue microarrays containing tumour and normal cores in a ratio of 3:2, from 99 surgically resected PBA patients, were used for IHC. IHC was performed on an automated platform using antibodies against KOC, S100P, mesothelin and MUC1. Tissue cores were scored for staining intensity and proportion of tissue stained using a Histoscore method (range, 0-300). Sensitivity and specificity for individual biomarkers, as well as biomarker panels, were determined with different cut-offs for positivity and compared by summary receiver operating characteristic (ROC) curve.

RESULTS

The expression of all four biomarkers was high in PBA versus normal ducts, with a mean Histoscore of 150 vs. 0.4 for KOC, 165 vs. 0.3 for S100P, 115 vs. 0.5 for mesothelin and 200 vs. 14 for MUC1 (p < .0001 for all comparisons). Five cut-offs were carefully chosen for sensitivity/specificity analysis. Four of these cut-offs, namely 5%, 10% or 20% positive cells and Histoscore 20 were identified using ROC curve analysis and the fifth cut-off was moderate-strong staining intensity. Using 20% positive cells as a cut-off achieved higher sensitivity/specificity values: KOC 84%/100%; S100P 83%/100%; mesothelin 88%/92%; and MUC1 89%/63%. Analysis of a panel of KOC, S100P and mesothelin achieved 100% sensitivity and 99% specificity if at least 2 biomarkers were positive for 10% cut-off; and 100% sensitivity and specificity for 20% cut-off.

CONCLUSION

A biomarker panel of KOC, S100P and mesothelin with at least 2 biomarkers positive was found to be an optimum panel with both 10% and 20% cut-offs in resection specimens from patients with PBA.

Utilization of ancillary studies in the cytologic diagnosis of biliary and pancreatic lesions: The Papanicolaou Society of Cytopathology Guidelines

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound guided fine needle aspiration, terminology and nomenclature of pancreatobiliary disease, ancillary testing and post-biopsy management. All documents are based on the expertise of the authors, a review of the literature, discussion of the draft document at several national and international meetings and synthesis of selected online comments of the draft document. This document presents the results of these discussions regarding the use of ancillary testing in the cytologic diagnosis of biliary and pancreatic lesions. Currently, fluorescence in-situ hybridization (FISH) appears to be the most clinically relevant ancillary technique for cytology of bile duct strictures. The addition of FISH analysis to routine cytologic evaluation appears to yield the highest sensitivity without loss in specificity. Loss of immunohistochemical staining for the protein product of the SMAD4 gene and positive staining for mesothelin support a diagnosis of ductal adenocarcinoma. Immunohistochemical markers for endocrine and exocrine differentiation are sufficient for a diagnosis of endocrine and acinar tumors. Nuclear staining for beta-catenin supports a diagnosis of solid-pseudopapillary neoplasm. Cyst fluid analysis for amylase and carcinoembryonic antigen aids in the pre-operative classification of pancreatic cysts. A number of gene mutations (KRAS, GNAS, von Hippel-Lindau, RNF43 and CTNNB1) may be of aid in the diagnosis of cystic neoplasms. Other ancillary techniques do not appear to improve diagnostic sensitivity sufficiently to justify their increased costs.

Guidelines for pancreaticobiliary cytology from the Papanicolaou Society of Cytopathology: A review

The newest installment on state-of-the-art standards of practice in cytopathology from the Papanicolaou Society of Cytopathology (PSC) focuses on the pancreaticobiliary system. Similar to the National Cancer Institute recommendations for aspiration cytology of the thyroid, the PSC guidelines for pancreaticobiliary cytology addresses indications, techniques, terminology and nomenclature, ancillary studies, and postprocedure management. Each committee was composed of a multidisciplinary group of experts in diagnosing, managing, and treating patients with pancreaticobiliary disease. Draft documents were posted on an interactive Web-based forum hosted by the PSC Web site (www.papsociety.org) and the topics of terminology, ancillary testing, and management were presented at national and international meetings over an 18-month period for discussion and feedback from practicing pathologists around the world. This review provides a synopsis of these guidelines.

Differentiation of pancreatic ductal adenocarcinoma from chronic pancreatitis by PAM4 immunohistochemistry

CONTEXT

PAM4 is a monoclonal antibody that shows high specificity for pancreatic ductal adenocarcinoma (PDAC) and its neoplastic precursor lesions. A PAM4-based serum immunoassay is able to detect 71% of early-stage patients and 91% with advanced disease. However, approximately 20% of patients diagnosed with chronic pancreatitis (CP) are also positive for circulating PAM4 antigen. The specificity of the PAM4 antibody is critical to the interpretation of the serum-based and immunohistochemical assays for detection of PDAC.

OBJECTIVE

To determine whether PAM4 can differentiate PDAC from nonneoplastic lesions of the pancreas.

DESIGN

Tissue microarrays of PDAC (N = 43) and surgical specimens from CP (N = 32) and benign cystic lesions (N = 19) were evaluated for expression of the PAM4 biomarker, MUC1, MUC4, CEACAM5/6, and CA19-9.

RESULTS

PAM4 and monoclonal antibodies (MAbs) to MUC1, MUC4, CEACAM5/6, and CA19-9 were each reactive with the majority of PDAC cases; however, PAM4 was the only monoclonal antibody not to react with adjacent, nonneoplastic parenchyma. Although PAM4 labeled 19% (6 of 32) of CP specimens, reactivity was restricted to pancreatic intraepithelial neoplasia associated with CP; inflamed tissues were negative in all cases. In contrast, MUC1, MUC4, CEACAM5/6, and CA19-9 were detected in 90%, 78%, 97%, and 100% of CP, respectively, with reactivity also present in nonneoplastic inflamed tissue.

CONCLUSIONS

PAM4 was the only monoclonal antibody able to differentiate PDAC (and pancreatic intraepithelial neoplasia precursor lesions) from benign, nonneoplastic tissues of the pancreas. These results suggest the use of PAM4 for evaluation of tissue specimens, and support its role as an immunoassay for detection of PDAC.

Utilization of ancillary studies in the cytologic diagnosis of biliary and pancreatic lesions: the Papanicolaou Society of Cytopathology guidelines for pancreatobiliary cytology

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound-guided fine-needle aspiration, terminology and nomenclature of pancreatobiliary disease, ancillary testing, and post-biopsy management. All documents are based on the expertise of the authors, a review of the literature, discussions of the draft document at several national and international meetings, and synthesis of selected online comments of the draft document. This document presents the results of these discussions regarding the use of ancillary testing in the cytologic diagnosis of biliary and pancreatic lesions. Currently, fluorescence in situ hybridization (FISH) appears to be the most clinically relevant ancillary technique for cytology of bile duct strictures. The addition of FISH analysis to routine cytologic evaluation appears to yield the highest sensitivity without loss in specificity. Loss of immunohistochemical staining for the protein product of the SMAD4 gene and positive staining for mesothelin support a diagnosis of ductal adenocarcinoma. Immunohistochemical markers for endocrine and exocrine differentiation are sufficient for a diagnosis of endocrine and acinar tumors. Nuclear staining for beta-catenin supports a diagnosis of solid-pseudopapilary neoplasm. Cyst fluid analysis for amylase and carcinoembryonic antigen aids in the preoperative classification of pancreatic cysts. Many gene mutations (KRAS, GNAS, VHL, RNF43, and CTNNB1) may be of aid in the diagnosis of cystic neoplasms. Other ancillary techniques do not appear to improve diagnostic sensitivity sufficiently to justify their increased costs.

Pancreatic cancer counterattack: MUC4 mediates Fas-independent apoptosis of antigen-specific cytotoxic T lymphocyte

Tumor-associated MUC4 mucin has considerable potential as an immunotherapy target for pancreatic cancer. In previous studies, we developed dendritic cell (DC) vaccines which elicited MUC4 antigen-specific cytotoxic T lymphocyte (MS-CTL) response against tumor cells in vitro. Due to the observation that MS-CTL apoptotic rate increased significantly when co-cultured with MUC4+ tumor cells compared with T2 cells, we investigated whether high expression levels of MUC4 in pancreatic cancer cells would have an effect on the significant increase of apoptosis rate of MS-CTLs. First, the adverse influence of regulatory T cells (Tregs) was eliminated by CD8+ T lymphocyte sorting before the induction of MS-CTLs. Then, we constructed clonal MUC4-knockdown HPAC pancreatic cancer sublines with different MUC4 expression for co-incubation system. By utilizing appropriate control to rule out the possible apoptosis-induced pathway of intrinsic activated cell-autonomous death (ACAD) and analogous antigen-dependent apoptosis of CTL (ADAC) in our study system, further analysis of the effect of MUC4 membrane-expression, supernatants and blockade of CTL surface Fas receptor on MS-CTL apoptosis was carried out. The results demonstrated that the level of MUC4 membrane expression strongly positively correlated with MS-CTL apoptosis and the influence of supernatants and Fas-blockade did not significantly correlate with MS-CTL apoptosis. This evidence suggested that there may be a novel counterattack pathway of pancreatic cancer cells, which is a MUC4-mediated, cell contact-dependent and Fas-independent process, to induce CTL apoptosis. Therefore, further exploration and understanding of the potential counterattack mechanisms is beneficial to enhance the efficacy of MUC4 specific tumor vaccines.

The usefulness of S100P, mesothelin, fascin, prostate stem cell antigen, and 14-3-3 sigma in diagnosing pancreatic adenocarcinoma in cytological specimens obtained by endoscopic ultrasound guided fine-needle aspiration

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the pancreas is an efficient and minimally invasive procedure for the diagnosis and staging of pancreatic adenocarcinoma. Because of some limitations of EUS-FNA in diagnosis of well-differentiated or early stage cancers, the purpose of this study is to assess the added benefit of immunohistochemistry. We studied five proteins overexpressed in pancreatic adenocarcinoma, namely, prostate stem cell antigen, fascin, 14-3-3 sigma, mesothelin and S100P utilizing immunohistochemistry on paraffin sections from cellblocks obtained by EUS-FNA. Sixty-two cases of EUS-FNA of the pancreas that had follow-up histological and/or clinical diagnosis and sufficient material in cell blocks were included. Using histological diagnosis and/or clinical outcome as the reference standard, EUS-FNA shows the highest sensitivity (95%) and specificity (91%) and is superior to any marker in this study. Among five antibodies, S100P reveals the best diagnostic characters showing 90% of sensitivity and 67% of specificity. Fascin shows high specificity (92%) but low sensitivity (38%). Mesothelin has a moderate sensitivity (74%) and low specificity (33%), PSCA and 14-3-3 show high sensitivity but zero specificity. S100P and mesothelin were useful in nine indeterminate cases. S100P correctly predicted six of seven cancers and one of one without cancer and mesothelin correctly diagnosed five of seven cancers and one of two noncancers in this group. EUS-FNA cytomorphology is superior to any of the immunohistochemical markers used in this study. Use of S100P and mesothelin in cytologically borderline cases can increase the diagnostic accuracy in this group.

CRABP-II is a highly sensitive and specific diagnostic molecular marker for pancreatic ductal adenocarcinoma in distinguishing from benign pancreatic conditions

CRABP-II, a retinoic acid binding protein, shuffles retinoic acid from cytoplasm into nucleus and forms a complex with nuclear retinoic acid receptor to facilitate transcriptional activities of retinoic acid. In this study, we studied the expression patterns of CRABP-II in pancreatic ductal adenocarcinoma (PDAC) compared with those in normal pancreas, chronic pancreatitis, and precancerous lesions. We showed no detectable expressions of CRABP-II in normal pancreatic parenchyma, normal ductal epithelium, and chronic pancreatitis. In contrast, the expression of CRABP-II was readily detected in all PDACs including metastatic PDACs. CRABP-II staining was also observed and progressively increased from pancreatic intraepithelial neoplasia 1 to 3. In addition, when fine needle aspiration specimens were evaluated from patients with PDAC, CRABP-II was positive in 55.6% cases if cytology diagnosis was "atypia," and in 87.5% cases, if "malignancy." Our study suggests that CRABP-II is highly and specifically expressed in PDAC and is more commonly expressed in high-grade precursor cancerous lesions than in low-grade lesions. Therefore, overexpression of CRABP-II is a late event of pancreatic carcinogenesis, and it could be used as a diagnostic marker to distinguish PDAC from other benign pancreatic conditions in both resection and cytology specimens.

Mucins in pancreatic cancer and its microenvironment

Pancreatic cancer remains a lethal malignancy with poor prognosis owing to therapeutic resistance, frequent recurrence and the absence of treatment strategies that specifically target the tumour and its supporting stroma. Deregulated cell-surface proteins drive neoplastic transformations and are envisioned to mediate crosstalk between the tumour and its microenvironment. Emerging studies have elaborated on the role of mucins in diverse biological functions, including enhanced tumorigenicity, invasiveness, metastasis and drug resistance through their characteristic O-linked and N-linked oligosaccharides (glycans), extended structures and unique domains. Multiple mucin domains differentially interact and regulate different components of the tumour microenvironment. This Review discusses: the expression pattern of various mucins in the pancreas under healthy, inflammatory, and cancerous conditions; the context-dependent attributes of mucins that differ under healthy and pathological conditions; the contribution of the tumour microenvironment in pancreatic cancer development and/or progression; diagnostic and/or prognostic efficacy of mucins; and mucin-based therapeutic strategies. Overall, this information should help to delineate the intricacies of pancreatic cancer by exploring the family of mucins, which, through various mechanisms in both tumour cells and the microenvironment, worsen disease outcome.

Immunocytochemistry for MUC4 and MUC16 is a useful adjunct in the diagnosis of pancreatic adenocarcinoma on fine-needle aspiration cytology

CONTEXT

Diagnoses rendered as atypical/suspicious for malignancy on fine-needle aspiration (FNA) of pancreatic mass lesions range from 2% to 29% in various studies. We have identified the expression of 3 genes, MUC4, MUC16, and NGAL that are highly upregulated in pancreatic adenocarcinoma. In this study, we analyzed the expression of these markers in FNA samples to determine whether they could improve sensitivity and specificity.

OBJECTIVE

To evaluate the utility of MUC4, MUC16, and NGAL in the evaluation of pancreatic FNA specimens.

DESIGN

Records of pancreatic FNAs performed during 10 consecutive years were reviewed. Unstained sections from corresponding cell blocks were immunostained for MUC4, MUC16, and NGAL (polyclonal). Immunostaining was assessed using the H-score (range, 0-3). Any case with an H-score of >0.5 was considered positive.

RESULTS

Cases were classified using cytomorphologic criteria as adenocarcinoma (31 of 64; 48.4%), benign (17 of 64; 26.6%), and atypical/suspicious (16 of 64; 25%). On follow-up, all cases (100%; 31 of 31) diagnosed as carcinoma on cytology were confirmed on biopsy/resection samples or by clinical follow-up (such as unresectable disease). Of the cases diagnosed as atypical/suspicious, 69% (11 of 16) were found to be positive for adenocarcinoma and 31% (5 of 16) were benign on subsequent follow-up. Overall sensitivity and specificity, respectively, for the various markers for the detection of pancreatic adenocarcinoma were as follows: MUC4 (74% and 100%), MUC16 (62.9% and 100%), and NGAL (61.3% and 58.8%). In cases that were atypical/suspicious on cytology, expression of MUC4 and MUC16 was 100% specific for carcinoma with sensitivities of 63.6% and 66.7%, respectively.

CONCLUSION

Immunocytochemistry for MUC4 and MUC16 appears to be a useful adjunct in the classification of pancreatic FNA samples, especially in cases that are equivocal (atypical/suspicious) for adenocarcinoma on cytomorphologic assessment.

MUC4 as a diagnostic marker in cancer

BACKGROUND

Mucins are high molecular mass glycoproteins whose role in diagnosis, prognosis and therapy is being increasingly recognized owing to their altered expression in a variety of carcinomas. MUC4, a membrane-bound mucin encoded by a gene located on chromosome locus 3q29, is aberrantly expressed in several cancers including those of the bile duct, breast, colon, esophagus, ovary, lung, prostate, stomach and pancreas.

OBJECTIVE

This review considers the potential use of the MUC4 expression pattern in the diagnosis and prognosis of various cancers.

RESULTS/CONCLUSION

MUC4 expression is a specific marker of epithelial tumors and its expression correlates positively with the degree of differentiation in several cancers. Importantly, MUC4 has emerged as a specific marker of dysplasia, being expressed in the earliest dysplastic lesions preceding several malignancies, including lethal pancreatic cancer. The presence of MUC4-specific antibodies in the serum and of the transcript in peripheral blood mononuclear cells of cancer patients raises the possibility of it emerging as a new diagnostic biomarker for bedside application in high-risk individuals and those with established cancer.

Aberrant expression of mucin core proteins and o-linked glycans associated with progression of pancreatic cancer

PURPOSE

Mucin expression is a common feature of most adenocarcinomas and features prominently in current attempts to improve diagnosis and therapy for pancreatic cancer and other adenocarcinomas. We investigated the expression of a number of mucin core proteins and associated O-linked glycans expressed in pancreatic adenocarcinoma-sialyl Tn (STn), Tn, T antigen, sialyl Lewis A (CA19-9), sialyl Lewis C (SLeC), Lewis X (LeX), and sialyl LeX (SLeX)-during the progression of pancreatic cancer from early stages to metastatic disease.

EXPERIMENTAL DESIGN

Immunohistochemical analyses of mucin and associated glycan expression on primary tumor and liver metastatic tumor samples were conducted with matched sets of tissues from 40 autopsy patients diagnosed with pancreatic adenocarcinoma, 14 surgically resected tissue samples, and 8 normal pancreata.

RESULTS

There were significant changes in mucin expression patterns throughout disease progression. MUC1 and MUC4 were differentially glycosylated as the disease progressed from early pancreatic intraepithelial neoplasias to metastatic disease. De novo expression of several mucins correlated with increased metastasis indicating a potentially more invasive phenotype, and we show the expression of MUC6 in acinar cells undergoing acinar to ductal metaplasia. A "cancer field-effect" that included changes in mucin protein expression and glycosylation in the adjacent normal pancreas was also seen.

CONCLUSIONS

There are significant alterations in mucin expression and posttranslational processing during progression of pancreatic cancer from early lesions to metastasis. The results are presented in the context of how mucins influence the biology of tumor cells and their microenvironment during progression of pancreatic cancer.

Establishment and characterization of a highly tumourigenic and cancer stem cell enriched pancreatic cancer cell line as a well defined model system

Standard cancer cell lines do not model the intratumoural heterogeneity situation sufficiently. Clonal selection leads to a homogeneous population of cells by genetic drift. Heterogeneity of tumour cells, however, is particularly critical for therapeutically relevant studies, since it is a prerequisite for acquiring drug resistance and reoccurrence of tumours. Here, we report the isolation of a highly tumourigenic primary pancreatic cancer cell line, called JoPaca-1 and its detailed characterization at multiple levels. Implantation of as few as 100 JoPaca-1 cells into immunodeficient mice gave rise to tumours that were histologically very similar to the primary tumour. The high heterogeneity of JoPaca-1 was reflected by diverse cell morphology and a substantial number of chromosomal aberrations. Comparative whole-genome sequencing of JoPaca-1 and BxPC-3 revealed mutations in genes frequently altered in pancreatic cancer. Exceptionally high expression of cancer stem cell markers and a high clonogenic potential in vitro and in vivo was observed. All of these attributes make this cell line an extremely valuable model to study the biology of and pharmaceutical effects on pancreatic cancer.