Mucins in neoplasms of pancreas, ampulla of Vater and biliary system

Establishment and characterization of a new intrahepatic cholangiocarcinoma cell line, ICC-X3

Intrahepatic cholangiocarcinoma (ICC) is an aggressive cancer of the biliary tract that is prone to recurrence and metastasis and is characterized by poor sensitivity to chemotherapy and overall prognosis. To address this challenge, the establishment of suitable preclinical models is critical. In this study, we successfully established a new ICC cell line, named ICC-X3, from the satellite lesions of one ICC patient. The cell line was characterized with respect to phenotypic, molecular, biomarker, functional and histological properties. STR confirmed that ICC-X3 was highly consistent with primary tumor tissue. ICC-X3 cells positively expressed CK7, CK19, E-cadherin, vimentin, and Ki67. ICC-X3 was all resistant to gemcitabine, paclitaxel, 5-FU, and oxaliplatin. The cell line was able to rapidly form xenograft tumors which were highly similar to the primary tumor. The missense mutation of TP53 exon was detected in ICC-X3 cells. ICC-X3 can be used as a good experimental model to study the progression, metastasis, and drug resistance of ICC.

Rare histological subtype of invasive micropapillary carcinoma in the ampulla of Vater: A case report

BACKGROUND

Carcinoma of the ampulla of Vater is an uncommon ampullo-pancreatobiliary neoplasm, and the most common histological type is adenocarcinoma with a tubular growth pattern. Invasive micropapillary carcinoma (IMPC) is an aggressive variant of adenocarcinoma in several organs that is associated with lymph node metastasis and poor prognosis. IMPC was first described as a histological subtype of breast cancer; however, IMPC of the ampulla of Vater is extremely rare, with only three articles reported in the English literature.

CASE SUMMARY

We have reported a case of IMPC of the ampulla of Vater in an 80-year-old man. Microscopically, the surface area of the carcinoma was composed of tubulopapillary structures mimicking intra-ampullary papillary-tubular neoplasm, and the deep invasive front area exhibited a pattern of IMPC. The carcinoma showed lymphatic invasion and extensive lymph node metastasis. The immunohistochemical study revealed mixed intestinal and gastric/pan-creatobiliary phenotypes.

CONCLUSION

This rare subtype tumor in the ampulla of Vater showed a histologically mixed phenotype and exhibited aggressive behavior.

Intraductal papillary neoplasm of intrahepatic bile ducts complicated by chronic disseminated intravascular coagulation and thrombosis: A case report

RATIONALE

Intraductal papillary neoplasm of the bile ducts (IPNB) is a relatively rare tumor that is clinically characterized by digestive symptoms. The concurrent occurrence of chronic disseminated intravascular coagulation (DIC) with thrombosis is an extremely rare combination, reported in patients with IPNB. The clinical features of chronic DIC include microangiopathic hemolytic anemia, thrombocytopenia, and hypofibrinogenemia. Here, we report the case of a mucin-producing IPNB patient with hematological abnormalities.

PATIENT CONCERNS

A 58-year-old male patient suffered from abdominal distension for more than 2 months with obstructive jaundice appearance. Abdominal contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography showed a neoplasm in the right hepatic lobe. Multiple intravascular fillings were found in the inferior vena cava, pulmonary artery, and right atrium. Anemia and hypofibrinogenemia were discovered through routine laboratory tests. The count of platelets began to decline 25 days after admission, while 1 month after hospitalization, the patient developed abdominal pain, fever, and shock.

DIAGNOSIS

Pathological examination demonstrated IPNB with a part of high-grade intraepithelial neoplasia. Cardiac and inferior vena cava emboli were diagnosed as thrombi without neoplastic cells. Immunohistochemically, tumor cells were positive for Vimentin (mesenchyme), CK7, CK19, MUC-1, MUC-5AC, MUC-6, S-100p (focal), Ki-67 (12%), and negative for Inhibin-α, ER, CK20, CEA, and MUC-2. Additionally, immunohistochemistry indicated that IPNB was a mucus-secretion gastric type. The laboratory tests confirmed the presence of chronic DIC.

INTERVENTIONS

The patient was given anticoagulant therapy before hepatectomy and right atrium thrombectomy was performed under cardiopulmonary bypass.

OUTCOMES

After anticoagulant therapy, the levels of hemoglobin, platelet, and fibrinogen of the patient returned to normal. Hepatectomy and thrombus removal was successfully performed. Then, the patient was discharged 12 days after the operation. After 12 months of follow-up, the patient recovered well without any hematologic abnormalities and no signs of tumor recurrence were observed.

LESSONS

IPNB may cause hematological complications, which can be easily misdiagnosed. It is essential to pay particular attention to the hematological abnormalities of patients with IPNB. Early detection and differential diagnosis of chronic DIC and thrombosis are necessary. We note that anticoagulant therapy coupled with surgery is an effective strategy to treat these complications.

A novel GNAS-mutated human induced pluripotent stem cell model for understanding GNAS-mutated tumors

A missense mutation of the guanine nucleotide binding protein alpha stimulating activity polypeptide 1 (GNAS) gene, typically Arg201Cys or Arg201His (R201H/R201C), leads to constitutive activation of the Gsα-cyclic AMP (cAMP) signaling pathway that causes several diseases. However, no germline mutations of GNAS have been identified to date, likely due to their lethality, and no robust human cell models have been generated. Therefore, the aim of this study was to generate GNAS-mutated disease-specific induced pluripotent stem cells as a model for these diseases. We then analyzed the functionality of this induced pluripotent stem cell model and differentiated epithelial cells. We generated disease-specific induced pluripotent stem cells by introducing a mutation in GNAS with the clustered regularly interspaced short palindromic repeats (CRISPR) nickase method, which has lower off-target effects than the conventional CRISPR/Cas9 method. We designed the target vector to contain the R201H mutation in GNAS, which was transfected into human control induced pluripotent stem cells (Nips-B2) by electroporation. We confirmed the establishment of GNAS^R201H-mutated (GNAS^R201H/+) induced pluripotent stem cells that exhibited a pluripotent stem cell phenotype. We analyzed the effect of the mutation on cAMP production, and further generated teratomas for immunohistochemical analysis of the luminal epithelial structure. GNAS-mutated induced pluripotent stem cells showed significantly higher levels of intracellular cAMP, which remained elevated state for a long time upon hormonal stimulation with parathyroid hormone or adrenocorticotropic hormone. Immunohistochemical analysis revealed that several mucins, including MUC1, 2, and MUC5AC, are expressed in cytokeratin 18 (CK18)-positive epithelial cells. However, we found few CK18-positive cells in mutated induced pluripotent stem cell-derived teratoma tissues, and reduced MUCINs expression in mutated epithelial cells. There was no difference in CDX2 expression; however, mutated epithelial cells were positive for CEA and CA19-9 expression. GNAS^R201H-mutated induced pluripotent stem cells and GNAS^R201H-mutated epithelial cells have distinct phenotypic and differentiation characteristics. We successfully established GNAS^R201H-mutated human induced pluripotent stem cells with increased cAMP production. Considering the differentiation potential of induced pluripotent stem cells, these cells will be useful as a model for elucidating the pathological mechanisms of GNAS-mutated diseases.

Cancer cell line-specific protein profiles in extracellular vesicles identified by proteomics

Extracellular vesicles (EVs), are important for intercellular communication in both physiological and pathological processes. To explore the potential of cancer derived EVs as disease biomarkers for diagnosis, monitoring, and treatment decision, it is necessary to thoroughly characterize their biomolecular content. The aim of the study was to characterize and compare the protein content of EVs derived from three different cancer cell lines in search of a specific molecular signature, with emphasis on proteins related to the carcinogenic process. Oral squamous cell carcinoma (OSCC), pancreatic ductal adenocarcinoma (PDAC) and melanoma brain metastasis cell lines were cultured in CELLine AD1000 flasks. EVs were isolated by ultrafiltration and size-exclusion chromatography and characterized. Next, the isolated EVs underwent liquid chromatography-mass spectrometry (LC-MS) analysis for protein identification. Functional enrichment analysis was performed for a more general overview of the biological processes involved. More than 600 different proteins were identified in EVs from each particular cell line. Here, 14%, 10%, and 24% of the identified proteins were unique in OSCC, PDAC, and melanoma vesicles, respectively. A specific protein profile was discovered for each cell line, e.g., EGFR in OSCC, Muc5AC in PDAC, and FN1 in melanoma vesicles. Nevertheless, 25% of all the identified proteins were common to all cell lines. Functional enrichment analysis linked the proteins in each data set to biological processes such as "biological adhesion", "cell motility", and "cellular component biogenesis". EV proteomics discovered cancer-specific protein profiles, with proteins involved in processes promoting tumor progression. In addition, the biological processes associated to the melanoma-derived EVs were distinct from the ones linked to the EVs isolated from OSCC and PDAC. The malignancy specific biomolecular cues in EVs may have potential applications as diagnostic biomarkers and in therapy.

Mucins in pancreatic cancer: A well-established but promising family for diagnosis, prognosis and therapy

Mucins are a family of multifunctional glycoproteins that mostly line the surface of epithelial cells in the gastrointestinal tract and exert pivotal roles in gut lubrication and protection. Pancreatic cancer is a lethal disease with poor early diagnosis, limited therapeutic effects, and high numbers of cancer‐related deaths. In this review, we introduce the expression profiles of mucins in the normal pancreas, pancreatic precursor neoplasia and pancreatic cancer. Mucins in the pancreas contribute to biological processes such as the protection, lubrication and moisturization of epithelial tissues. They also participate in the carcinogenesis of pancreatic cancer and are used as diagnostic biomarkers and therapeutic targets. Herein, we discuss the important roles of mucins that lead to the lethality of pancreatic adenocarcinoma, particularly MUC1, MUC4, MUC5AC and MUC16 in disease progression, and present a comprehensive analysis of the clinical application of mucins and their promising roles in cancer treatment to gain a better understanding of the role of mucins in pancreatic cancer.

Pancreatic Intraductal Papillary Mucinous Neoplasm With Elevated Pre-Operative Cystic Carcinoembryonic Antigen Level: A Histopathologic Correlation

Background

To study the relationship between carcinoembryonic antigen (CEA) level, intraductal papillary mucinous neoplasm (IPMN) subtype, and the presence of invasive carcinoma.

Methods

Cystic CEA level and the following pathologic variables: subtypes of IPMN, size of cystic lesion, presence of dysplasia or carcinoma, and main or branch duct involvement from 45 IPMN cases were analyzed.

Results

There was a significant correlation between pre-operative cystic fluid CEA level and the intensity of luminal CEA staining. However, there was no correlation between CEA level and cystic mucinous secretions or mucinous epithelial cytoplasm CEA staining, mucin glycoprotein expression, size of lesion, grade of dysplasia or presence of invasive carcinoma. CEA level was neither sensitive nor specific for the presence of invasive carcinoma.

Conclusions

Cystic CEA level may not be a reliable determinant of the presence or absence of invasive carcinoma in IPMNs, and its use to assess risk of malignancy may be limited.

Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

the bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells.

Expression and Serum Levels of Mucin 5AC (MUC5AC) as a Biomarker for Cholangiocarcinoma: a Meta-analysis

AIM

The potential of biomarkers in detecting early cholangiocarcinoma (CCA) is facilitated by examining CCA-associated proteins from primary studies. One such protein is mucin 5AC (MUC5AC) but inconsistency of reported associations between its expression/serum levels and CCA prompts a meta-analysis to obtain more precise estimates.

METHODS

A literature search yielded 17 included articles where multiple data in some raised the number of studies to 22. We calculated pooled odds ratios (OR) and 95% confidence intervals from negative and positive readings of MUC5AC levels. Data were subgrouped by ethnicity, detection method, sample source, and cancer type.

RESULTS

Outcome in the overall analysis was non-significant but those in the subgroups were. Thus, significant associations (P < 0.001) indicating high MUC5AC levels were found in three subgroups: (i) Thai (OR 8.32) and (ii) serum (OR 4.52). Heterogeneity of these two outcomes (I² = 90-93%) was erased with outlier treatment (I² = 0%) which also modulated the pooled effects (OR 2.48-2.59). (iii) Immunoblot (OR 2.61) had low initial heterogeneity (I² = 2%). Robustness and significant tests for interaction (P_interaction = 0.01-0.02) improved MUC5AC associations with CCA in the Thai population.

CONCLUSIONS

Our pooled effect findings target the biomarker potential of MUC5AC to the Thai population.

Anatomical, histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin-producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub-classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho-molecular groups can currently be discriminated. Large-duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2-fusions are typically seen in small-duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.

Detection and proteomic characterization of extracellular vesicles in human pancreatic juice

AIMS

The prognosis of patients with pancreatic cancer has remained virtually unchanged with a high mortality rate compared to other types of cancers. An earlier detection would provide a time window of opportunity for treatment and prevention of deaths. In the present study we investigated extracellular vesicle (EV)-associated potential biomarkers for pancreatic cancer by directly assessing EV size-based subpopulations in pancreatic juice samples of patients with chronic pancreatitis or pancreatic cancer. In addition, we also studied blood plasma and pancreatic cancer cell line-derived EVs.

METHODS

Comparative proteomic analysis was performed of 102 EV preparations from human pancreatic juices, blood, and pancreatic cancer cell lines Capan-1 and MIA PaCa-2. EV preparations were also characterized by electron microscopy, tunable resistive pulse sensing, and flow cytometry.

RESULTS

Here we describe the presence of EVs in human pancreatic juice samples. Pancreatic juice EV-associated proteins that we identified as possible candidate markers for pancreatic cancer included mucins, such as MUC1, MUC4, MUC5AC, MUC6 and MUC16, CFTR, and MDR1 proteins. These candidate biomarkers could also be detected by flow cytometry in EVs found in pancreatic juice and those secreted by pancreatic cancer cell lines.

CONCLUSIONS

Together our data show that detection and characterization of EVs directly in pancreatic juice is feasible and may prove to be a valuable source of potential biomarkers of pancreatic cancer.

Diagnostic usefulness of KL-6 concentration of bile in biliary tract cancer

The sensitivity of bile cytology for biliary tract cancer varies from 6-64%, and hence remains unsatisfactory. Sialylated carbohydrate antigen KL-6 mucin is positive in biliary tract cancer tissues and serum KL-6 levels are significantly increased in intrahepatic ductal adenocarcinoma patients compared with healthy individuals. The aim of the present study was to evaluate the usefulness of the KL-6 concentration of bile for the diagnosis of biliary tract cancer. Bile cytology and measurements of bile KL-6 concentration were conducted for 43 patients (25 biliary tract cancers and 18 benign biliary disease). The concentration of KL-6 in the bile of the biliary tract cancer group was compared with the benign biliary disease group. The diagnostic ability was assessed by using receiver operating characteristic curves (ROC). The mean KL-6 concentration of bile for biliary tract cancer (34.6±51.6 U/ml) was increased compared with benign biliary disease (5.2±3.9 U/ml, P<0.001). The area under the ROC for diagnosis of biliary tract cancer was 0.84 for benign biliary disease. When the cut-off level of the KL-6 concentration of bile was 8.6 U/ml, the sensitivity, specificity, and accuracy of the KL-6 concentration of bile alone for the diagnosis of biliary tract cancer were 72, 89, and 79%, respectively. Adding the bile KL-6 concentration to bile cytology measurements, the sensitivity for the diagnosis of biliary tract cancer was increased significantly (100%, P=0.0184). The KL-6 concentration of bile may strengthen the sensitivity of bile cytology for biliary tract cancer.

Improved Detection of Circulating Epithelial Cells in Patients with Intraductal Papillary Mucinous Neoplasms

Early detection strategies for pancreatic ductal adenocarcinoma are needed. This article describes a high‐sensitivity platform for detection of epithelial cells shed from preneoplastic lesions at a high risk of becoming malignant and a combination of technologies that could be used for early detection of disease in high‐risk patients.

Background.

Recent work has demonstrated early shedding of circulating epithelial cells (CECs) from premalignant intraductal papillary mucinous neoplasms (IPMNs). However, the potential use of CECs as a “liquid biopsy” for patients with IPMNs has been limited by antigen dependence of CEC isolation devices and the lack of robust detection biomarkers across CEC phenotypes.

Materials and Methods.

We utilized a negative depletion microfluidic platform to purify CECs from contaminating leukocytes and coupled this platform with immunofluorescence, RNA in situ hybridization, and RNA sequencing (RNA‐seq) detection and enumeration.

Results.

Using established protein (EpCAM, cytokeratins) and novel noncoding RNA (HSATII, cytokeratins) biomarkers, we detected CECs in 88% of patients bearing IPMN lesions. RNA‐seq analysis for MUC genes confirm the likely origin of these CECs from pancreatic lesions.

Conclusion.

Our findings increase the sensitivity of detection of these cells and therefore could have clinical implications for cancer risk stratification.

Implications for Practice.

This work describes a high‐sensitivity platform for detection of epithelial cells shed from preneoplastic lesions at high risk of malignant transformation. Further research efforts are underway to define the transcriptional programs that might allow discrimination between circulating cells released from tumors that will become malignant and cells released from tumors that will not. After further refinement, this combination of technologies could be deployed for monitoring and early detection of patients at high risk for developing new or recurrent pancreatic malignancies.

Novel Biomarkers for Pancreatic Cysts

With increased utilization and ongoing advancements in cross-sectional abdominal imaging, the identification of a pancreatic cyst has become a frequent finding. While many pancreatic cysts are associated with a benign clinical course, others may transform into pancreatic ductal adenocarcinoma. However, distinguishing a benign from a malignant pancreatic cyst or pancreatic cyst with malignant potential on the basis of standard clinical findings, imaging parameters and ancillary studies can be challenging. Hence, a significant interest within the past decade has been the identification of novel biomarkers to accurately classify and prognosticate a pancreatic cyst. Within this review, we discuss novel DNA, miRNA, protein and metabolite biomarkers, and their relevance in clinical practice. In addition, we focus on future areas of research that have the potential to change pancreatic cyst management.

Clinicopathological Study of Carcinoma of the Ampulla of Vater with Special Reference to MUC1, MUC2 and MUC5AC Expression

INTRODUCTION

The ampulla of Vater consists of papilla, common channel, distal common bile duct and the distal main pancreatic duct. Ampullary carcinomas arise from two different types of mucosa, reflecting their broad histomorphological spectrum. Adenocarcinomas originating in the ampulla of Vater are classified as having either 'Intestinal' or 'Pancreatobiliary' type of differentiation. Pancreatobiliary type has consistently shown a worse prognosis. Various types of mucins are distributed in normal tissues and gastrointestinal tumours. MUC1, MUC2 and MUC5AC are known to be the most important amongst all.

AIM

To study clinicopathological features of different types of carcinoma of ampulla with MUC1, MUC2 and MUC5AC expression.

MATERIALS AND METHODS

We included 20 cases of ampullary adenocarcinoma in this study, diagnosed after radical surgery. The histopathological slides were reviewed and the tumours were classified into intestinal type, pancreatobilliary and other types. Representative block of tumours was subjected to immunohistochemical (IHC) study with MUC1, MUC2 and MUC5AC antibodies. Results were subsequently analysed.

RESULTS

Pancreaticobiliary type of ampullary carcinoma cases predominated (50%) over intestinal type (25%). Carcinomas of "other types" included one case each of mucinous carcinoma, adenosquamous carcinoma and undifferentiated carcinoma and well differentiated neuroendocrine tumours. Pancreatobiliary type of carcinomas was associated with higher tumour stage and grade and lymph node metastasis. All the pancreatobiliary type expressed MUC1 and all intestinal type carcinomas expressed MUC2. MUC 5AC expression was seen predominantly in pancreatobiliary type of ampullary carcinomas.

CONCLUSION

Mucin markers are associated with two different subtypes of ampullary carcinomas which have different prognosis. Immunohistochemical study of mucin expression can define the different types of carcinomas of ampulla of Vater with better objective criteria.

Mucins in pancreatic cancer: biological role, implications in carcinogenesis and applications in diagnosis and therapy

Pancreatic cancer is the fourth highest cause of cancer mortality in the world. It has very low survival rates owing to late diagnosis resulting from the absence of accurate diagnostic tools and effective therapies. Hence, there is a pressing need to develop new diagnostic and therapeutic tools. In the recent years, there has been new evidence implicating the importance of mucins in pancreatic carcinogenesis. Mucins belong to a group of heavily glycosylated proteins, and are often aberrantly expressed in a number of cancers such as pancreatic cancer. Therefore, this literature review will summarise the role of mucins and mucin expression in pancreatic neoplasms. Subsequently the paper will also discuss the most recent advances in the biological properties of mucins and their role in carcinogenesis and resistance to chemotherapy. Then it will conclude on the newest developments in diagnosis and therapy based on mucins for pancreatic cancer.

Molecular Drivers of Pancreatic Cancer Pathogenesis: Looking Inward to Move Forward

Pancreatic cancer (PC) continues to rank among the most lethal cancers. The consistent increase in incidence and mortality has made it the seventh leading cause of cancer-associated deaths globally and the third in the United States. The biggest challenge in combating PC is our insufficient understanding of the molecular mechanism(s) underlying its complex biology. Studies during the last several years have helped identify several putative factors and events, both genetic and epigenetic, as well as some deregulated signaling pathways, with implications in PC onset and progression. In this review article, we make an effort to summarize our current understanding of molecular and cellular events involved in the pathogenesis of pancreatic malignancy. Specifically, we provide up-to-date information on the genetic and epigenetic changes that occur during the initiation and progression of PC and their functional involvement in the pathogenic processes. We also discuss the impact of the tumor microenvironment on the molecular landscape of PC and its role in aggressive disease progression. It is envisioned that a better understanding of these molecular factors and the mechanisms of their actions can help unravel novel diagnostic and prognostic biomarkers and can also be exploited for future targeted therapies.