New Developments in the Molecular Mechanisms of Pancreatic Tumorigenesis

The nucleolin antagonist N6L and paclitaxel combination treatment could be a new promising therapeutic strategy for pancreatic ductal adenocarcinoma therapy

Pancreatic cancer (PCa) is one of the most devastating cancers with few clinical signs and no truly effective therapy. In recent years, our team has demonstrated that nucleolin antagonists such as N6L could be a therapeutic alternative for this disease. In order to study a possible clinic development of N6L (multivalent pseudopeptide), we undertook to study the effect of combination of N6L with chemotherapies classically used for PCa on the survival of pancreatic cancer cells. Thus, the combined effect of N6L with either gemcitabine, FOLFOX and paclitaxel (PTX) on the survival of PANC-1, Mia-PaCa-2 and BxPC3 was studied and shown additive effect. In addition, analysis of the data by Combenefit software indicates that there are synergistic effects between N6L and the 3 chemotherapy molecules tested with more sensitive effects with the N6L-PTX combination. This result was confirmed by associating N6L and paclitaxel on porous calcium carbonate particles loaded with cyclodextrin (CD) encapsulating PTX and carrying N6L at their surface. Porous calcium carbonate particles present highly benefits for biological purposes because of their large surface area and their high stability in neutral media. As for CD, it presents the advantage of owing hydrophilic exterior and a less polar cavity in the center. We have then combined the advantageous features of both porous and negatively charged surfaces of calcium carbonate (CaCO3) particles and host molecules CD for developing carrier enabling all at once the loading of PTX (hydrophobic drug) and N6L (cationic drug). This association generates water-soluble particles capable of targeting via N6L and delivering paclitaxel to tumor cells.

Application of imaging technology for the diagnosis of malignancy in the pancreaticobiliary duodenal junction (Review)

The pancreaticobiliary duodenal junction (PBDJ) is the connecting area of the pancreatic duct, bile duct and duodenum. In a broad sense, it refers to a region formed by the head of the pancreas, the pancreatic segment of the common bile duct and the intraduodenal segment, the descending and the horizontal part of the duodenum, and the soft tissue around the pancreatic head. In a narrow sense, it refers to the anatomical Vater ampulla. Due to its complex and variable anatomical features, and the diversity of pathological changes, it is challenging to make an early diagnosis of malignancy at the PBDJ and define the histological type. The unique anatomical structure of this area may be the basis for the occurrence of malignant tumors. Therefore, understanding and subclassifying the anatomical configuration of the PBDJ is of great significance for the prevention and treatment of malignant tumors at their source. The present review comprehensively discusses commonly used imaging techniques and other new technologies for diagnosing malignancy at the PBDJ, offering evidence for physicians and patients to select appropriate examination methods.

Precision Targeting Strategies in Pancreatic Cancer: The Role of Tumor Microenvironment

Pancreatic cancer demonstrates an ever-increasing incidence over the last years and represents one of the top causes of cancer-associated mortality. Cells of the tumor microenvironment (TME) interact with cancer cells in pancreatic ductal adenocarcinoma (PDAC) tumors to preserve cancer cells' metabolism, inhibit drug delivery, enhance immune suppression mechanisms and finally develop resistance to chemotherapy and immunotherapy. New strategies target TME genetic alterations and specific pathways in cell populations of the TME. Complex molecular interactions develop between PDAC cells and TME cell populations including cancer-associated fibroblasts, myeloid-derived suppressor cells, pancreatic stellate cells, tumor-associated macrophages, tumor-associated neutrophils, and regulatory T cells. In the present review, we aim to fully explore the molecular landscape of the pancreatic cancer TME cell populations and discuss current TME targeting strategies to provide thoughts for further research and preclinical testing.

Molecular Characterization and Xenotransplantation of Pancreatic Cancer Using Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA)

Pancreatic cancer has one of the worst prognoses among all malignancies and few available treatment options. Patient-derived xenografts can be used to develop personalized therapy for pancreatic cancer. Endoscopic ultrasound fine-needle aspiration (EUS-FNA) may provide a powerful alternative to surgery for obtaining sufficient tissue for the establishment of patient-derived xenografts. In this study, EUS-FNA samples were obtained for 30 patients referred to the Ottawa Hospital, Ottawa, Ontario, Canada. These samples were used for xenotransplantation in NOD-SCID mice and for genetic analyses. The gene expression of pancreatic-cancer-relevant genes in xenograft tumors was examined by immunohistochemistry. Targeted sequencing of both the patient-derived tumors and xenograft tumors was performed. The xenografts' susceptibility to oncolytic virus infection was studied by infecting xenograft-derived cells with VSV∆51-GFP. The xenograft take rate was found to be 75.9% for passage 1 and 100% for passage 2. Eighty percent of patient tumor samples were successfully sequenced to a high depth for 42 cancer genes. Xenograft histological characteristics and marker expression were maintained between passages. All tested xenograft samples were susceptible to oncoviral infection. We found that EUS-FNA is an accessible, minimally invasive technique that can be used to acquire adequate pancreatic cancer tissue for the generation of patient-derived xenografts and for genetic sequencing.

Microphysiological systems as reliable drug discovery and evaluation tools: Evolution from innovation to maturity

Microphysiological systems (MPSs), also known as organ-on-chip or disease-on-chip, have recently emerged to reconstitute the in vivo cellular microenvironment of various organs and diseases on in vitro platforms. These microfluidics-based platforms are developed to provide reliable drug discovery and regulatory evaluation testbeds. Despite recent emergences and advances of various MPS platforms, their adoption of drug discovery and evaluation processes still lags. This delay is mainly due to a lack of rigorous standards with reproducibility and reliability, and practical difficulties to be adopted in pharmaceutical research and industry settings. This review discusses the current and potential use of MPS platforms in drug discovery processes while considering the context of several key steps during drug discovery processes, including target identification and validation, preclinical evaluation, and clinical trials. Opportunities and challenges are also discussed for the broader dissemination and adoption of MPSs in various drug discovery and regulatory evaluation steps. Addressing these challenges will transform long and expensive drug discovery and evaluation processes into more efficient discovery, screening, and approval of innovative drugs.

Identification of key biomarkers and associated pathways of pancreatic cancer using integrated transcriptomic and gene network analysis

Pancreatic cancer shows malignancy around the world standing in 4th position for causing death globally. This cancer is majorly divided into exocrine and neuroendocrine where exocrine pancreatic ductal adenocarcinoma is observed to be nearly 85% of cases. The lack of diagnosis of pancreatic cancer is considered to be one of the major drawbacks to the prognosis and treatment of pancreatic cancer patients. The survival rate after diagnosis is very low, due to the higher incidence of drug resistance to cancer which leads to an increase in the mortality rate. The transcriptome analysis for pancreatic cancer involves dataset collection from the ENA database, incorporating them into quality control analysis to the quantification process to get the summarized read counts present in collected samples and used for further differential gene expression analysis using the DESeq2 package. Additionally, explore the enriched pathways using GSEA software and represented them by utilizing the enrichment map finally, the gene network has been constructed by Cytoscape software. Furthermore, explored the hub genes that are present in the particular pathways and how they are interconnected from one pathway to another has been analyzed. Finally, we identified the CDKN1A, IL6, and MYC genes and their associated pathways can be better biomarker for the clinical processes to increase the survival rate of of pancreatic cancer.

Genetics, Genomics and Emerging Molecular Therapies of Pancreatic Cancer

The number of cases of pancreatic cancers in 2019 in Poland was 3852 (approx. 2% of all cancers). The course of the disease is very fast, and the average survival time from the diagnosis is 6 months. Only <2% of patients live for 5 years from the diagnosis, 8% live for 2 years, and almost half live for only about 3 months. A family predisposition to pancreatic cancer occurs in about 10% of cases. Several oncogenes in which somatic changes lead to the development of tumours, including genes BRCA1/2 and PALB2, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1, are involved in pancreatic cancer. Between 4% and 10% of individuals with pancreatic cancer will have a mutation in one of these genes. Six percent of patients with pancreatic cancer have NTRK pathogenic fusion. The pathogenesis of pancreatic cancer can in many cases be characterised by homologous recombination deficiency (HRD)-cell inability to effectively repair DNA. It is estimated that from 24% to as many as 44% of pancreatic cancers show HRD. The most common cause of HRD are inactivating mutations in the genes regulating this DNA repair system, mainly BRCA1 and BRCA2, but also PALB2, RAD51C and several dozen others.

Survival and Prognostic Factors in Patients With Pancreatic Colloid Carcinoma Compared With Pancreatic Ductal Adenocarcinoma

OBJECTIVES

Colloid carcinoma (CC) is a rare subtype of pancreatic carcinoma. The aims of the study are to characterize the clinicopathological features and to evaluate the overall survival (OS) of patients with CC.

METHODS

Patients diagnosed with pancreatic CC and pancreatic ductal adenocarcinoma (PDAC) between 2004 and 2016 were identified from the National Cancer Database using International Classification of Disease-O-3 morphology (8480/3 and 8140/3) and topography (C25) codes. Kaplan-Meier analysis and Cox proportional hazards models were used to analyze OS.

RESULTS

Fifty-six thousand eight hundred forty-six patients were identified. A total of 2430 patients (4.3%) were diagnosed with pancreatic CC. Males constituted 52.8% of CC and 52.2% of PDAC. Colloid carcinoma presented with pathological stage I disease more often (16.7% vs 5.9%) and stage IV disease less often (42.1% vs 52.4%) than PDAC (P < 0.001). Stage I CC received chemotherapy (36.0% vs 59.4%) and neoadjuvant chemotherapy (4.4% vs 14.2%) less often compared with PDAC (P < 0.001). Statistically significant improved OS was seen among stage I, II, and IV CC compared with PDAC.

CONCLUSIONS

Pancreatic CC presented as stage I disease more often compared with PDAC. Neoadjuvant chemotherapy was administered more often in stage I PDAC compared with CC. Colloid carcinoma had improved OS compared with PDAC among all stages except stage III.

A comprehensive review of pancreatic cancer and its therapeutic challenges

Pancreatic cancer is a devastating and lethal human malignancy with no curable chemo-treatments available thus far. More than 90% of pancreatic tumors are formed from ductal epithelium as pancreatic ductal adenocarcinoma (PDAC), which often accompany with the expression of mutant K-ras. The incidences of pancreatic cancer are expected to increase rapidly worldwide in the near future, due to environmental pollution, obesity epidemics and etc. The dismal prognosis of this malignancy is contributed to its susceptibility to tumor micro-metastasis from inception and the lack of methods to detect precursor lesions at very early stages of the onset until clinical symptoms occur. In recent years, basic and clinical studies have been making promising progresses for discovering markers to determine the subtypes or stages of this malignancy, which allow effectively implementing personalized therapeutic interventions. The purpose of this review is to discuss the existing knowledge of the molecular mechanisms of pancreatic cancer and the current state of treatment options with the emphasis on targeting therapeutic approaches. The specific focuses are on the molecular mechanisms of the disease, identifications of drug resistance, establishment of immune escaping mechanisms as well as potential of targeting identified pathways in combinations with existing chemo-drugs.

On the Origin of Pancreatic Cancer: Molecular Tumor Subtypes in Perspective of Exocrine Cell Plasticity

Pancreatic ductal adenocarcinoma (PDAC) is a devastating type of cancer. While many studies have shed light into the pathobiology of PDAC, the nature of PDAC's cell of origin remains under debate. Studies in adult pancreatic tissue have unveiled a remarkable exocrine cell plasticity including transitional states, mostly exemplified by acinar to ductal cell metaplasia, but also with recent evidence hinting at duct to basal cell transitions. Single-cell RNA sequencing has further revealed intrapopulation heterogeneity among acinar and duct cells. Transcriptomic and epigenomic relationships between these exocrine cell differentiation states and PDAC molecular subtypes have started to emerge, suggesting different ontogenies for different tumor subtypes. This review sheds light on these diverse aspects with particular focus on studies with human cells. Understanding the "masked ball" of exocrine cells at origin of PDAC and leaving behind the binary acinar vs duct cell classification may significantly advance our insights in PDAC biology.

Impact of Driver Mutations on the Evolution of Isolated Metachronous Lung Metastasis of Pancreatic Ductal adenocarcinoma

BACKGROUND

The incidence of pancreatic ductal adenocarcinoma (PDAC) is increasing sharply. The survival of patients with metastases is usually about a year. However, the occurrence of isolated lung metastases after resection of the primary tumor, although rare, seems to indicate a better prognosis, with an average survival ranging from 40 to 80 months. KRAS, TP53, CDK2NA, and SMAD4 are the most common driver genes in pancreatic adenocarcinoma.

OBJECTIVE

Our objectives were to determine whether a link exists between survival and mutations of driver genes in patients with isolated pulmonary metastases.

METHODS

All patients who underwent curative surgery in our institution between 2010 and 2018 were included in the study. From these, we identified patients for whom recurrence was only pulmonary and those with metastases at other sites. KRAS, TP53, CDK2NA, and SMAD4 were analyzed on the primary tumor of patients with pulmonary metastases.

RESULTS

Among 233 patients diagnosed with PDAC in our institution over 8 years, 41 (17.5%) underwent curative surgery. Of these, seven (3%) developed isolated pulmonary metastases, 32 developed other metastases, and two did not recur. Median survival was 59 months for patients with isolated lung metastases and 25.3 months for patients with metastases at other sites. An absence of mutations of two driver genes in primary tumors (CDK2NA and SMAD4) was observed in patients with isolated pulmonary metastases.

CONCLUSIONS

The absence of mutations in the CDK2NA and SMAD4 tumor-suppressor genes in patients with isolated pulmonary metastases contrasts with the commonly observed high rates of driver gene mutations and suggests a link with overall survival.

Hyperpolarized Magnetic Resonance and Artificial Intelligence: Frontiers of Imaging in Pancreatic Cancer

BACKGROUND

There is an unmet need for noninvasive imaging markers that can help identify the aggressive subtype(s) of pancreatic ductal adenocarcinoma (PDAC) at diagnosis and at an earlier time point, and evaluate the efficacy of therapy prior to tumor reduction. In the past few years, there have been two major developments with potential for a significant impact in establishing imaging biomarkers for PDAC and pancreatic cancer premalignancy: (1) hyperpolarized metabolic (HP)-magnetic resonance (MR), which increases the sensitivity of conventional MR by over 10,000-fold, enabling real-time metabolic measurements; and (2) applications of artificial intelligence (AI).

OBJECTIVE

Our objective of this review was to discuss these two exciting but independent developments (HP-MR and AI) in the realm of PDAC imaging and detection from the available literature to date.

METHODS

A systematic review following the PRISMA extension for Scoping Reviews (PRISMA-ScR) guidelines was performed. Studies addressing the utilization of HP-MR and/or AI for early detection, assessment of aggressiveness, and interrogating the early efficacy of therapy in patients with PDAC cited in recent clinical guidelines were extracted from the PubMed and Google Scholar databases. The studies were reviewed following predefined exclusion and inclusion criteria, and grouped based on the utilization of HP-MR and/or AI in PDAC diagnosis.

RESULTS

Part of the goal of this review was to highlight the knowledge gap of early detection in pancreatic cancer by any imaging modality, and to emphasize how AI and HP-MR can address this critical gap. We reviewed every paper published on HP-MR applications in PDAC, including six preclinical studies and one clinical trial. We also reviewed several HP-MR-related articles describing new probes with many functional applications in PDAC. On the AI side, we reviewed all existing papers that met our inclusion criteria on AI applications for evaluating computed tomography (CT) and MR images in PDAC. With the emergence of AI and its unique capability to learn across multimodal data, along with sensitive metabolic imaging using HP-MR, this knowledge gap in PDAC can be adequately addressed. CT is an accessible and widespread imaging modality worldwide as it is affordable; because of this reason alone, most of the data discussed are based on CT imaging datasets. Although there were relatively few MR-related papers included in this review, we believe that with rapid adoption of MR imaging and HP-MR, more clinical data on pancreatic cancer imaging will be available in the near future.

CONCLUSIONS

Integration of AI, HP-MR, and multimodal imaging information in pancreatic cancer may lead to the development of real-time biomarkers of early detection, assessing aggressiveness, and interrogating early efficacy of therapy in PDAC.

A Thought-Provoking Case of Successfully Treated Carcinoma of the Head of the Pancreas with Metachronous Lung Metastasis: Impact of Distal Spleno-Renal Shunt for Regional Invasion on Long-Term Period after Pancreaticoduodenectomy

When performing pancreaticoduodenectomy with resection of the confluence of the superior mesenteric vein and portal vein, division of the splenic vein may cause sinistral portal hypertension resulting in gastrointestinal bleeding, splenic congestion, and hypersplenism. To prevent these adverse events, it is important to intentionally decompress the splenic vein. This report is of a 68-year-old woman with stage IA carcinoma of the head of the pancreas who survived for more than six years following tumor resection and pancreaticoduodenectomy and distal splenorenal shunt. A 68-year-old woman was diagnosed with carcinoma of the head of the pancreas that involved the confluence of the superior mesenteric vein, portal vein, and splenic vein. No unresectable cancer sites or distant metastases were detected. Pancreaticoduodenectomy with resection of the confluence of the superior mesenteric vein and portal vein was performed. The superior mesenteric vein and portal vein were anastomosed in the end-to-end fashion, and the remnant splenic vein was anastomosed to the superior aspect of the left renal vein in the end-to-side fashion. At 22 months after the initial surgery, the patient underwent partial lung resection for a metachronous lung metastasis. For 6 years after the initial surgery, the venous reconstructions have maintained their patency without any obstruction of splenic venous flow, and the patient has remained in good health without further metastases or recurrences. This case has shown the importance of early diagnosis of carcinoma of the head of the pancreas, as appropriate and timely surgical management can result in good outcome. This patient responded well and remains alive six years following pancreaticoduodenectomy and preservation of the spleen with the use of a distal splenorenal shunt.

Emerging antibody therapies for pancreatic adenocarcinoma: a review of recent phase 2 trials

Introduction: Pancreatic adenocarcinoma is now the third-leading cause of cancer-related deaths in the US which can be attributed to rising incidence, diagnosis at advanced stages and early development of metastasis. Systemic therapy remains palliative with early development of resistance possibly related to the constitutive activation of 'undruggable' KRAS, immunosuppressive microenvironment, and intense desmoplasia. The advancements in molecular biology has led to the development and investigation of targeted and immune therapeutics.Areas covered: This study provides a comprehensive review of the literature to further the understanding of molecular targets with their respective antibody-based therapies in clinical development in pancreatic cancer. PubMed was systematically searched for English-language articles discussing antibody-based therapies under phase 2 clinical trial investigation in pancreatic adenocarcinoma.Expert opinion: PDAC remains highly resistant to chemotherapy with no significant improvement in survival for patients with advanced or metastatic cancer. Unfortunately, the majority of the antibody-based targeted and immune therapeutics have failed to meet their primary efficacy endpoints in early phase trials. However, there are a few promising antibody-based drugs with intriguing preliminary data that merit further investigation, while many more continue to be developed and investigated preclinically, and in early phase trials.

Parvovirus-Based Combinatorial Immunotherapy: A Reinforced Therapeutic Strategy against Poor-Prognosis Solid Cancers

Resistance to anticancer treatments poses continuing challenges to oncology researchers and clinicians. The underlying mechanisms are complex and multifactorial. However, the immunologically "cold" tumor microenvironment (TME) has recently emerged as one of the critical players in cancer progression and therapeutic resistance. Therefore, TME modulation through induction of an immunological switch towards inflammation ("warming up") is among the leading approaches in modern oncology. Oncolytic viruses (OVs) are seen today not merely as tumor cell-killing (oncolytic) agents, but also as cancer therapeutics with multimodal antitumor action. Due to their intrinsic or engineered capacity for overcoming immune escape mechanisms, warming up the TME and promoting antitumor immune responses, OVs hold the potential for creating a proinflammatory background, which may in turn facilitate the action of other (immunomodulating) drugs. The latter provides the basis for the development of OV-based immunostimulatory anticancer combinations. This review deals with the smallest among all OVs, the H-1 parvovirus (H-1PV), and focuses on H-1PV-based combinatorial approaches, whose efficiency has been proven in preclinical and/or clinical settings. Special focus is given to cancer types with the most devastating impact on life expectancy that urgently call for novel therapies.

Human splenic TER cells: A relevant prognostic factor acting via the artemin-GFRα3-ERK pathway in pancreatic ductal adenocarcinoma

Splenectomy is routinely performed during distal or total pancreatectomy (DP or TP) for pancreatic ductal adenocarcinoma (PDAC), but information about its oncological value is limited. TER cells, nonimmune cells discovered in the spleens of tumour-bearing mice, are elicited by tumours and promote tumour progression, while their role in the clinical outcomes of patients with PDAC remains unclear. In our study, postoperative specimens from 622 patients who underwent DP or TP with splenectomy were analysed by flow cytometry or immunofluorescence, and the relationship between splenic TER cell count and clinical parameters was calculated. We also purified human TER cells for functional experiments and mechanistic studies. We found that TER cell numbers were increased only in the spleens of patients with PDAC but not in PDAC tissue and adjacent pancreatic tissue. High splenic TER cell counts independently predicted poor prognosis (P < .001) and indicated large tumour size, lymph node metastasis, advanced 8th AJCC/mAJCC stage and high CA19-9 classification (all P < .050) in patients with PDAC. Mechanistic analysis showed that TER cells express artemin, which facilitates the proliferation and invasion of PDAC cells by activating GFRα3-ERK signalling. Our study reveals that TER cell count is an indicator of poor prognosis of PDAC, while splenectomy during pancreatic surgery might provide oncological benefits in addition to ensuring the radical resection of PDAC.

An engineered pancreatic cancer model with intra-tumoral heterogeneity of driver mutations

Pancreatic ductal adenocarcinoma (PDAC) is a complex disease with significant intra-tumoral heterogeneity (ITH). Currently, no reliable PDAC tumor model is available that can present ITH profiles in a controlled manner. We develop an in vitro microfluidic tumor model mimicking the heterogeneous accumulation of key driver mutations of human PDAC using cancer cells derived from genetically engineered mouse models. These murine pancreatic cancer cell lines have KPC (Kras and Trp53 mutations) and KIC genotypes (Kras mutation and Cdkn2a deletion). Also, the KIC genotypes have two distinct phenotypes - mesenchymal or epithelial. The tumor model mimics the ITH of human PDAC to study the effects of ITH on the gemcitabine response. The results show gemcitabine resistance induced by ITH. Remarkably, it shows that cancer cell-cell interactions induce the gemcitabine resistance potentially through epithelial-mesenchymal-transition. The tumor model can provide a useful testbed to study interaction mechanisms between heterogeneous cancer cell subpopulations.

Cannabidiol and Oxygen-Ozone Combination Induce Cytotoxicity in Human Pancreatic Ductal Adenocarcinoma Cell Lines

Pancreatic cancer (PC) is related to lifestyle risks, chronic inflammation, and germline mutations in BRCA1/2, ATM, MLH1, TP53, or CDKN2A. Surgical resection and adjuvant chemotherapy are the main therapeutic strategies but are less effective in patients with high-grade tumors. Oxygen-ozone (O2/O3) therapy is an emerging alternative tool for the treatment of several clinical disorders. O2/O3 therapy has been found to ameliorate mechanisms promoting chronic pain and inflammation, including hypoxia, inflammatory mediators, and infection. The advantages of using cannabinoids have been evaluated in vitro and in vivo models of several human cancers. Regarding PDAC, activation of cannabinoid receptors was found to induce pancreatic cancer cell apoptosis without affecting the normal pancreas cells. In a murine model of PDAC, a combination of cannabidiol (CBD) and gemcitabine increased survival length by nearly three times. Herein, we evaluate the anticancer effect of CBD and O2/O3, alone or in combination, on two human PDAC cell lines, PANC-1 and MiaPaCa-2, examining expression profiles of 92 pancreatic adenocarcinoma associated genes, cytotoxicity, migration properties, and cell death. Finally, we assess the combination effects with gemcitabine and paclitaxel. Summarizing, for the first time the antitumoral effect of combined therapy with CBD and oxygen-ozone therapy in PDAC is evidenced.

Differences between Well-Differentiated Neuroendocrine Tumors and Ductal Adenocarcinomas of the Pancreas Assessed by Multi-Omics Profiling

Most pancreatic neuroendocrine tumors (PNETs) are indolent, while pancreatic ductal adenocarcinomas (PDACs) are particularly aggressive. To elucidate the basis for this difference and to establish the biomarkers, by using the deep sequencing, we analyzed somatic variants across coding regions of 409 cancer genes and measured mRNA/miRNA expression in nine PNETs, eight PDACs, and four intestinal neuroendocrine tumors (INETs). There were 153 unique somatic variants considered pathogenic or likely pathogenic, found in 50, 57, and 24 genes in PDACs, PNETs, and INETs, respectively. Ten and 11 genes contained a pathogenic mutation in at least one sample of all tumor types and in PDACs and PNETs, respectively, while 28, 34, and 11 genes were found to be mutated exclusively in PDACs, PNETs, and INETs, respectively. The mRNA and miRNA transcriptomes of PDACs and NETs were distinct: from 54 to 1659 differentially expressed mRNAs and from 117 to 250 differentially expressed miRNAs exhibited high discrimination ability and resulted in models with an area under the receiver operating characteristics curve (AUC-ROC) >0.9 for both miRNA and mRNA. Given the miRNAs high stability, we proposed exploring that class of RNA as new pancreatic tumor biomarkers.

Novel Poly(ADP-ribose) Polymerase-1 Inhibitor DDHCB Inhibits Proliferation of BRCA Mutant Breast Cancer Cell In Vitro and In Vivo through a Synthetic Lethal Mechanism

Poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors are drugs that are effectively used to treat breast cancer. We synthesized a novel bromophenol derivative ethyl (E)-4-(2-(2,3-dibromo-4,5-dimethoxybenzylidene)hydrazine-1-carbothioamido)benzoate (DDHCB) as a novel PARP-1 inhibitor. Our study found that DDHCB could inhibit PARP-1 activity with an IC₅₀ value of 58.3 nM. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazolium bromide (MTT) assay indicated that DDHCB could selectively inhibit proliferation of BRCA mutant cells and demonstrate the ability of synthetic lethality. DDHCB could also induce DNA double-strand breaks with the ability to increase the foci quantitation of γ-H2AX. Moreover, DDHCB could increase PARP-1-DNA trapping and inhibit PAR formation in HCC-1937 cells. Further investigation showed that DDHCB induced apoptosis and G2/M cycle arrest. Finally, we found that DDHCB inhibited the growth of HCC-1937 xenografts with low toxicity. In vivo mechanisms showed that the level of γ-H2AX was increased in the DDHCB-treated tumors, indicating the PARP-1 inhibition ability of DDHCB in vivo. Our study results indicated that the future development of DDHCB for the treatment of breast cancer is promising.

Targeting Epigenetic Dependencies in Solid Tumors: Evolutionary Landscape Beyond Germ Layers Origin

Extensive efforts recently witnessed the complexity of cancer biology; however, molecular medicine still lacks the ability to elucidate hidden mechanisms for the maintenance of specific subclasses of rare tumors characterized by the silent onset and a poor prognosis (e.g., ovarian cancer, pancreatic cancer, and glioblastoma). Recent mutational fingerprints of human cancers highlighted genomic alteration occurring on epigenetic modulators. In this scenario, the epigenome dependency of cancer orchestrates a broad range of cellular processes critical for tumorigenesis and tumor progression, possibly mediating escaping mechanisms leading to drug resistance. Indeed, in this review, we discuss the pivotal role of chromatin remodeling in shaping the tumor architecture and modulating tumor fitness in a microenvironment-dependent context. We will also present recent advances in the epigenome targeting, posing a particular emphasis on how this knowledge could be translated into a feasible therapeutic approach to individualize clinical settings and improve patient outcomes.

Integrin beta 4 (ITGB4) and its tyrosine-1510 phosphorylation promote pancreatic tumorigenesis and regulate the MEK1-ERK1/2 signaling pathway

Pancreatic cancer is the fourth leading cause of cancer death, with a 5-year survival rate of only 1–4%. Integrin-mediated cell adhesion is critical for the initiation, progression, and metastasis of cancer. In this study we investigated the role of integrin β4 (ITGB4) and its phosphorylation at tyrosine Y1510 (p-ITGB4-Y1510) in the tumorigenesis of pancreatic cancer. We analyzed the expression of ITGB4 and p-ITGB4-Y1510 in pancreatic cancer tissue and cell lines using immunohistochemistry, Western blot, or semi-quantitative reverse transcription PCR. ITGB4 and p-ITGB4-Y1510 were highly expressed in pancreatic cancer (n = 176) compared with normal pancreatic tissue (n = 171). High p-ITGB4-Y1510 expression correlated with local invasion and distant metastasis of pancreatic cancer, and high ITGB4 was significantly associated with poor survival of patients. Inhibition of ITGB4 by siRNA significantly reduced migration and invasion of PC-1.0 and AsPC-1 cells. Overexpression of the mutant ITGB4-Y1510A (a mutation of tyrosine to alanine at 1510 position) in PC-1.0 and AsPC-1 cells not only blocked the ITGB4 phosphorylation at Y1510 but also suppressed the expression of ITGB4 (p < 0.05 vs. wild-type ITGB4). The transfection of PC-1.0 and AsPC-1 cells with ITGB4-Y1510A significantly decreased the level of p-mitogen-activated protein kinase kinase (MEK)1 (T292) and p-extracellular signal-regulated kinase (ERK)1/2 but did not affect the level of p-MEK1 (T386) and p-MEK2 (T394). Overall, our study showed that ITGB4 and its phosphorylated form promote cell migration and invasion in pancreatic cancer and that p-ITGB4-Y1510 regulates the downstream MEK1-ERK1/2 signaling cascades. Targeting ITGB4 or its phosphorylation at Y1510 may be a novel therapeutic option for pancreatic cancer.

Long-term Risk of Malignancy in Branch-Duct Intraductal Papillary Mucinous Neoplasms

BACKGROUND & AIMS

Long-term outcomes of patients with branch-duct intraductal papillary mucinous neoplasms (IPMNs), particularly those after 5 years of surveillance, have not been fully evaluated in large studies. We analyzed incidences of IPMN-derived carcinoma and concomitant ductal adenocarcinoma (pancreatic ductal adenocarcinoma [PDAC]) over 20 years in a large population of patients.

METHODS

We identified 1404 consecutive patients (52% women; mean age, 67.5 years) with a diagnosis of branch-duct IPMN, from 1994 through 2017, at the University of Tokyo in Japan. Using a competing risk analysis, we estimated cumulative incidence of pancreatic carcinoma, overall and by carcinoma type. We used competing risks proportional hazards models to estimate subdistribution hazard ratios (SHRs) for incidences of carcinomas. To differentiate IPMN-derived and concomitant carcinomas, we collected genomic DNA from available paired samples of IPMNs and carcinomas and detected mutations in GNAS and KRAS by polymerase chain reaction and pyrosequencing.

RESULTS

During 9231 person-years of follow-up, we identified 68 patients with pancreatic carcinomas (38 patients with IPMN-derived carcinomas and 30 patients with concomitant PDACs); the overall incidence rates were 3.3%, 6.6%, and 15.0% at 5, 10, and 15 years, respectively. Among 804 patients followed more than 5 years, overall cumulative incidence rates of pancreatic carcinoma were 3.5% at 10 years and 12.0% at 15 years from the initial diagnosis. The size of the IPMN and the diameter of the main pancreatic duct associated with incidence of IPMN-derived carcinoma (SHR 1.85; 95% confidence interval 1.38-2.48 for a 10-mm increase in the IPMN size and SHR 1.56; 95% confidence interval 1.33-1.83 for a 1-mm increase in the main pancreatic duct diameter) but not with incidence of concomitant PDAC.

CONCLUSIONS

In a large long-term study of patients with branch-duct IPMNs, we found the 5-year incidence rate of pancreatic malignancy to be 3.3%, reaching 15.0% at 15 years after IPMN diagnosis. We observed heterogeneous risk factor profiles between IPMN-derived and concomitant carcinomas.

Review of the diagnosis and management of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms are common lesions with the potential of harbouring/developing a pancreatic cancer. An accurate evaluation of intraductal papillary mucinous neoplasms with high-resolution imaging techniques and endoscopic ultrasound is mandatory in order to identify patients worthy either of surgical treatment or surveillance. In this review, the diagnosis and management of patients with intraductal papillary mucinous neoplasms are discussed with a specific focus on current guidelines. Areas of uncertainty are also discussed, as there are controversies related to the optimal indications for surgery, surveillance protocols and surveillance discontinuation.

Pancreatic Ductal Adenocarcinoma and Its Precursor Lesions: Histopathology, Cytopathology, and Molecular Pathology

Pancreatic ductal adenocarcinoma is one of the most aggressive malignant neoplasms with poor outcomes. At the time of diagnosis, the disease is usually at an advanced stage and only a minority is eligible for surgical resection. To improve the prognosis, it is essential to diagnose and treat the disease in an early stage before its progression into an invasive disease. This article reviews clinical features, histopathology, cytopathology, and molecular alterations of pancreatic ductal adenocarcinoma and its precursors. Moreover, we review a recently updated two-tier classification system for precursor lesions, new findings in premalignant cystic neoplasms, and recently updated staging criteria for invasive carcinoma based on the Cancer Staging Manual, eighth edition, from the American Joint Committee on Cancer. Finally, we discuss the potential clinical applications of the rapidly growing molecular and genetic information of pancreatic cancer and its precursors.

Exploring the Molecular Crosstalk between Pancreatic Bud and Mesenchyme in Embryogenesis: Novel Signals Involved

Pancreatic organogenesis is a multistep process that requires the cooperation of several signaling pathways. In this context, the role of pancreatic mesenchyme is important to define the epithelium development; nevertheless, the precise space–temporal signaling activation still needs to be clarified. This study reports a dissection of the pancreatic embryogenesis, highlighting the molecular network surrounding the epithelium–mesenchyme interaction. To investigate this crosstalk, pancreatic epithelium and surrounding mesenchyme, at embryonic day 10.5, were collected through laser capture microdissection (LCM) and characterized based on their global gene expression. We performed a bioinformatic analysis to hypothesize crosstalk interactions, validating the most promising genes and verifying the precise localization of their expression in the compartments, by RNA in situ hybridization (ISH). Our analyses pointed out also the c-Met gene, a very well-known factor involved in stimulating motility, morphogenesis, and organ regeneration. We also highlighted the potential crosstalk between Versican (Vcan) and Syndecan4 (Sdc4) since these genes are involved in pancreatic tissue repair, strengthening the concept that the same signaling pathways required during pancreatic embryogenesis are also involved in tissue repair. This finding leads to novel strategies for obtaining functional pancreatic stem cells for cell replacement therapies.

Intraductal Papillary Mucinous Neoplasms Arise From Multiple Independent Clones, Each With Distinct Mutations

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are lesions that can progress to invasive pancreatic cancer and constitute an important system for studies of pancreatic tumorigenesis. We performed comprehensive genomic analyses of entire IPMNs to determine the diversity of somatic mutations in genes that promote tumorigenesis.

METHODS

We microdissected neoplastic tissues from 6-24 regions each of 20 resected IPMNs, resulting in 227 neoplastic samples that were analyzed by capture-based targeted sequencing. Somatic mutations in genes associated with pancreatic tumorigenesis were assessed across entire IPMN lesions, and the resulting data were supported by evolutionary modeling, whole-exome sequencing, and in situ detection of mutations.

RESULTS

We found a high prevalence of heterogeneity among mutations in IPMNs. Heterogeneity in mutations in KRAS and GNAS was significantly more prevalent in IPMNs with low-grade dysplasia than in IPMNs with high-grade dysplasia (P < .02). Whole-exome sequencing confirmed that IPMNs contained multiple independent clones, each with distinct mutations, as originally indicated by targeted sequencing and evolutionary modeling. We also found evidence for convergent evolution of mutations in RNF43 and TP53, which are acquired during later stages of tumorigenesis.

CONCLUSIONS

In an analysis of the heterogeneity of mutations throughout IPMNs, we found that early-stage IPMNs contain multiple independent clones, each with distinct mutations, indicating their polyclonal origin. These findings challenge the model in which pancreatic neoplasms arise from a single clone. Increasing our understanding of the mechanisms of IPMN polyclonality could lead to strategies to identify patients at increased risk for pancreatic cancer.

Differential diagnosis and analysis of pancreatic cancer resectability using CT and MRI

The purpose of this publication is to comprehend the modern achievements of radiological diagnosis in surgical oncopancreatology via a critical analysis of recent English-language publications. CT and MRI are essential diagnostic methods in surgical and oncological pancreatology. The possibilities of tomography examination regarding analysis of tumor dimension, CT criteria for pancreatic cancer diagnosis, assessment of vascular invasion, differential diagnosis of tumors, as well as estimation of possible early postoperative complications and radiological features of the region of interest after neoadjuvant and adjuvant therapy for pancreatic tumors are critically analyzed. The role of modern diagnostic methods in improvement of treatment directly related to the early staging of pancreatic tumors is negligible, since the factors affecting the phases of slow and rapid tumor growth are unclear. Most likely, cyclic clinical and radiological evaluation of the pancreas will not give the expected results and is associated with advanced financial and physical costs. Perhaps, one of the approaches for effective treatment of pancreatic cancer will be the recognition of the need for laboratory and instrumental examinations by each patient. Acceptable frequency of examinations and own funds are determined by a patients himself in this case.

Research progress and design optimization of CAR-T therapy for pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant cancer with limited treatment options. Chimeric antigen receptor T cells (CAR-T) are genetically engineered T cells that can specifically kill tumor cells without major histocompatibility complex restriction. Encouraging progress in CAR-T therapy for PDAC has been made in preclinical and early phase clinical trials. Challenges in CAR-T therapy for solid tumors still exist, including immunosuppressive microenvironment, interstitial barrier, poor chemotaxis, and the "on-target, off-tumor" effect. Applying neoantigens of PDAC as targets for CAR-T therapy, recognizing the CAR-T subgroup with better antitumor effect, and designing a CAR-T system targeting stroma of PDAC may contribute to develop a powerful CAR-T therapy for PDAC in the future.

Genetic testing vs microforceps biopsy in pancreatic cysts: Systematic review and meta-analysis

BACKGROUND

Carcinoembryonic antigen (CEA) and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms. Genetic testing and microforceps biopsy are promising tools for pre-operative diagnostic improvement but comparative performance of both methods is unknown.

AIM

To compare the accuracy of genetic testing and microforceps biopsy in pancreatic cysts referred for surgery.

METHODS

We performed a literature search in Medline, Scopus, and Web of Science for studies evaluating genetic testing of cystic fluid and microforceps biopsy of pancreatic cysts, with endoscopic ultrasound with fine-needle aspiration (EUS-FNA) prior to surgery and surgical pathology as reference standard for diagnosis. We evaluated the diagnostic accuracy for: 1- benign cysts; 2- mucinous low-risk cysts; 3- high-risk cysts, and the diagnostic yield and rate of correctly identified cysts with microforceps biopsy and molecular analysis. We also assessed publication bias, heterogeneity, and study quality.

RESULTS

Eight studies, including 1206 patients, of which 203 (17%) referred for surgery who met the inclusion criteria were analyzed in the systematic review, and seven studies were included in the meta-analysis. Genetic testing and microforceps biopsies were identical for diagnosis of benign cysts. Molecular analysis was superior for diagnosis of both low and high-risk mucinous cysts, with sensitivities of 0.89 (95%CI: 0.79-0.95) and 0.57 (95%CI: 0.42-0.71), specificities of 0.88 (95%CI: 0.75-0.95) and 0.88 (95%CI: 0.80-0.93) and AUC of 0.9555 and 0.92, respectively. The diagnostic yield was higher in microforceps biopsies than in genetic analysis (0.73 vs 0.54, respectively) but the rates of correctly identified cysts were identical (0.73 with 95%CI: 0.62-0.82 vs 0.71 with 95%CI: 0.49-0.86, respectively).

CONCLUSION

Genetic testing and microforceps biopsies are useful second tests, with identical results in benign pancreatic cysts. Genetic analysis performs better for low- and high-risk cysts but has lower diagnostic yield.

Protective potential of miR-146a-5p and its underlying molecular mechanism in diverse cancers: a comprehensive meta-analysis and bioinformatics analysis

Background/aims

Studies have shown that miR-146a-5p was differentially expressed in diverse cancers, but the associations between miR-146a-5p expression and prognosis across multiple types of cancer as well its potential targets and downstream pathways have not been comprehensively analyzed. In this study, we performed the first meta-analysis of the prognostic value of miR-146a-5p expression in diverse malignancies and explored prospective targets of miR-146a-5p and related signaling pathways.

Methods

A thorough search for articles related to miR-146a-5p was performed, and RNA-seq data from The Cancer Genome Atlas (TCGA) and microarray data from gene expression omnibus profiles were used to collect information about the prognostic value of miR-146a-5p. A comprehensive meta-analysis was conducted. Twelve platforms in miRWalk 2.0 were applied to predict targets of miR-146a-5p. TCGA RNA-seq data were used to validate the inverse relationships between miR-146a-5p and its likely targets. Subsequently, gene ontology and pathway analyses were conducted using Funrich version 3.1.3. Potential protein–protein interaction (PPI) networks were constructed. Potential target genes of miR-146a-5p in lung cancer were validated by RT-qPCR.

Results

We included 10 articles in the meta-analysis. In a pooled analysis, the high miR-146a-5p expression group showed a better overall survival in solid cancers, particularly in reproductive system cancers and digestive system cancers. A total of 120 predicted target genes were included in a bioinformatics analysis. Five pathways involving phospholipase C (PLC) and aquaporins (AQPs) were the most significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways. Moreover, the PPI network displayed the related signaling pathways and interactions among proteins. AQP1 and FYN were validated by RT-qPCR to be potential targets of miR-146a-5p in lung cancer.

Conclusion

There is a close link between high miR-146a-5p expression and better overall survival in 21 types of solid cancer, especially in reproductive system and digestive system cancers. Furthermore, miR-146a-5p could inhibit diverse malignancies by modulating pathways linked to PLC or AQPs. In summary, miR-146a-5p is a potential prognostic biomarker and therapeutic target for various cancers.

Single-cell sequencing defines genetic heterogeneity in pancreatic cancer precursor lesions

Intraductal papillary mucinous neoplasms (IPMNs) are precursors to pancreatic cancer; however, little is known about genetic heterogeneity in these lesions. The objective of this study was to characterize genetic heterogeneity in IPMNs at the single-cell level. We isolated single cells from fresh tissue from ten IPMNs, followed by whole genome amplification and targeted next-generation sequencing of pancreatic driver genes. We then determined single-cell genotypes using a novel multi-sample mutation calling algorithm. Our analyses revealed that different mutations in the same driver gene frequently occur in the same IPMN. Two IPMNs had multiple mutations in the initiating driver gene KRAS that occurred in unique tumor clones, suggesting the possibility of polyclonal origin or an unidentified initiating event preceding this critical mutation. Multiple mutations in later-occurring driver genes were also common and were frequently localized to unique tumor clones, raising the possibility of convergent evolution of these genetic events in pancreatic tumorigenesis. Single-cell sequencing of IPMNs demonstrated genetic heterogeneity with respect to early and late occurring driver gene mutations, suggesting a more complex pattern of tumor evolution than previously appreciated in these lesions. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.