Monika Bauden

Pancreatic cancer : Yesterday, today and tomorrow

Pancreatic cancer is one of our most lethal malignancies. Despite substantial improvements in the survival rates for other major cancer forms, pancreatic cancer survival rates have remained relatively unchanged since the 1960s. Pancreatic cancer is usually detected at an advanced stage and most treatment regimens are ineffective, contributing to the poor overall prognosis. Herein, we review the current understanding of pancreatic cancer, focusing on central aspects of disease management from radiology, surgery and pathology to oncology.

Protein deep sequencing applied to biobank samples from patients with pancreatic cancer.

PurposePancreatic cancer is commonly detected at advanced stages when the tumor is no longer amenable to surgical resection. Therefore, finding biomarkers for early stage disease is urgent. Here, we show that high-definition mass spectrometry (HDMSE) can be used to identify serum protein alterations associated with early stage pancreatic cancer.MethodsWe analyzed serum samples from patients with resectable pancreatic cancer, benign pancreatic disease, and healthy controls. The SYNAPT G2-Si platform was used in a data-independent manner coupled with ion mobility. The dilution of the samples with yeast alcohol dehydrogenase tryptic digest of known concentration allowed the estimated amounts of each identified protein to be calculated (Silva et al. in Anal Chem 77:2187–2200, 2005; Silva et al. in Mol Cell Proteomics 5:144–156, 2006). A global protein expression comparison of the three study groups was made using label-free quantification and bioinformatic analyses.ResultsTwo-way unsupervised hierarchical clustering revealed 134 proteins that successfully classified pancreatic cancer patients from the controls, and identified 40 proteins that showed a significant up-regulation in the pancreatic cancer group. This discrimination reliability was further confirmed by principal component analysis. The differentially expressed candidates were aligned with protein network analyses and linked to biological pathways related to pancreatic tumorigenesis. Pancreatic disease link associations could be made for BAZ2A, CDK13, DAPK1, DST, EXOSC3, INHBE, KAT2B, KIF20B, SMC1B, and SPAG5, by pathway network linkages to p53, the most frequently altered tumor suppressor in pancreatic cancer.ConclusionThese pancreatic cancer study candidates may provide new avenues of research for a noninvasive blood-based diagnosis for pancreatic tumor stratification.

Enrichment of Murine CD68+CCR2+ and CD68+CD206+ Lung Macrophages in Acute Pancreatitis-Associated Acute Lung Injury

Acute lung injury (ALI) is an important cause of mortality in critically ill patients. Acute pancreatitis (AP) is one of the risk factors for developing this syndrome. Among the inflammatory cells, macrophages have a key role in determining the severity of the acute lung injury. In the lungs, macrophages constitute a heterogeneous cell population distributed in different compartments. Changes in not only the macrophage count, but also in their phenotype have been seen during the course of lung injury. A murine ductal ligation model of acute pancreatitis showed substantial morphological changes in the pancreas and lungs. Immunohistochemistry showed neutrophil recruitment into both organs after 9 hours and later on. F4/80+ cells in the pancreas increased in the ligated animals, though there was not a significant difference in their number in the lungs as compared to sham operated animals. Flow cytometry analysis of lung macrophages demonstrated an enrichment of F4/80− CD68+CCR2+ and F4/80− CD68+CD206+ lung macrophages in ligated animals (AP) as compared to the sham operated group. The level of interleukin-6 in plasma increased 3 hours after ligation compared to the sham operated group, as a first indicator of a systemic inflammatory response. This study suggests a role for F4/80− CD68+ macrophages in the pathogenesis of acute lung injury in acute pancreatitis. Studying lung macrophages for different phenotypic markers, their polarization, activation and recruitment, in the context of acute lung injury, is a novel area to potentially identify interventions which may improve the outcome of acute lung injury.

Immune checkpoint therapy for pancreatic cancer

Novel treatment modalities are necessary for pancreatic cancer. Immunotherapy with immune checkpoint inhibition has shown effect in other solid tumors, and could have a place in pancreatic cancer treatment. Most available clinical studies on immune checkpoint inhibitors for pancreatic cancer are not yet completed and are still recruiting patients. Among the completed trials, there have been findings of a preliminary nature such as delayed disease progression and enhanced overall survival after treatment with immune checkpoint inhibitors in mono- or combination therapy. However, due to small sample sizes, major results are not yet identifiable. The present article provides a clinical overview of immune checkpoint inhibition in pancreatic cancer. PubMed, ClinicalTrials.gov and American Society of Clinical Oncology’s meeting abstracts were systematically searched for relevant clinical studies. Four articles, five abstracts and 25 clinical trials were identified and analyzed in detail.

Relationship between tumour size and outcome in pancreatic ductal adenocarcinoma

The size of pancreatic ductal adenocarcinoma (PDAC) at diagnosis is an indicator of outcome. Previous studies have focused mostly on patients with resectable disease. The aim of this study was to investigate the relationship between tumour size and risk of metastasis and death in a large PDAC cohort, including all stages.

Comparison of MUC4 expression in primary pancreatic cancer and paired lymph node metastases

Abstract Objective. Mucin 4 (MUC4) is a transmembrane glycoprotein that is expressed in pancreatic ductal adenocarcinoma (PDAC), but not in normal pancreatic tissue. MUC4 has a proposed role in pancreatic tumor progression and metastasis. The purpose of this pilot study was to investigate MUC4 expression during PDAC metastasis by comparing the expression in the primary tumor and paired lymph node metastases from the same patient. Material and methods. Surgical specimens from 17 cases of primary PDAC and paired lymph node metastases were immunohistochemically analyzed for MUC4 expression. The modified histochemical score (H-score) was used for staining assessment. Results. Positive staining for MUC4 was detected in most primary and metastatic PDAC tumors (15/17 vs. 14/17). The concordance for MUC4 expression in primary tumors and corresponding lymph node metastases was 82%. In two cases, the primary tumor was MUC4-positive and the lymph node metastases were negative, while in one patient with a MUC4-negative primary tumor, the lymph node metastasis was positive. The distribution of H-score for expression of MUC4 significantly correlated (r = 0.615; p = 0.009) between primary tumors and paired metastatic lesions. Conclusions: MUC4 was observed in both primary and matched metastatic tumors with a high level of concordance, suggesting that MUC4 expression is retained following PDAC metastasis.

Pancreatic cancer stroma: controversies and current insights

Abstract Pancreatic cancer is characterized by a dense stromal response. The stroma includes a heterogeneous mass of cells, including pancreatic stellate cells, fibroblasts, immune cells and nerve cells, as well as extracellular matrix proteins, cytokines and growth factors, which interact with the tumor cells. Previous research has indicated that stromal elements contribute to tumor growth and aggressiveness. However, recent studies suggest that some elements of the stroma may actually restrain the tumor. This review focuses on the complex interactions between the stromal microenvironment and tumor cells, discussing molecular mechanisms and potential future diagnostic and therapeutic approaches by targeting the stroma.

In vitro cytotoxicity evaluation of HDAC inhibitor Apicidin in pancreatic carcinoma cells subsequent time and dose dependent treatment.

Apicidin is a potent histone deacetylase inhibitor (HDACI) that selectively binds to histone deacetylases (HDACs) class I and interferes with the deacetylation process, which results in modification of acetylation level of cellular proteins. The aim of the study was to investigate the potential time and dose dependent cytotoxicity of the test compound, Apicidin, in pancreatic cancer cells Capan-1 and Panc-1 as well as estimate maximal tolerable dose (MTD) of the test agent and determine EC50 using four complementary colorimetric cytotoxicity or viability assays. The cells were treated with increasing concentrations of Apicidin (0-5000nM) for 2, 4 and 6h (short term exposure) or 24, 48 and 72h (long term exposure) before conducting cytotoxic analyses with lactate dehydrogenase assay or viability analyses with sulforhodamine B (SRB), methyl tetrazolium (MTT) and crystal violet (CV) assays. In order to investigate whether Apicidin irreversibly affects the cells already during the short term exposure, the medium containing Apicidin was removed and replaced with fresh culturing medium after 6h of treatment. The cells were then incubated for additional 24, 48 or 72h before carrying out the analysis. The results obtained from cytotoxicity and viability assays indicated, that Apicidin was well tolerated by both cell lines at concentrations below 100nM at any given time point and at all applied concentrations during the short term (6h or less) treatment. Continuous prolonged term exposures (48h or greater) of the cells to Apicidin with concentration exceeding 100nM resulted in significantly increasing cytotoxicity and sustained significant loss of cell viability. Moreover, long term exposure of pancreatic cancer cells Capan-1 and Panc-1 to Apicidin concentrations exceeding 100nM showed an initial anti-proliferative effect before cytotoxicity onset. In summary, MTD was exposure time dependent and estimated to 100nM for long term treatment and to at least 5000nM for treatment not greater than 6h. EC50 concentration of Apicidin was established after long term treatment, however with some variation when comparing the different assays and cell lines. Results from this study may encourage reinvestigating the capacity of potent HDACI Apicidin as an attractive agent for interfering with the deacetylation process catalyzed by HDACs for potential pancreatic cancer intervention.

Cancer Cell Radiobiological Studies Using In-House-Developed α-Particle Irradiator.

An α-particle irradiator, enabling high-precision irradiation of cells for in vitro studies, has been constructed. The irradiation source was a (241)Am source, on which well inserts containing cancer cells growing in monolayer were placed. The total radioactivity, uniformity, and α-particle spectrum were determined by use of HPGe detector, Gafchromic dosimetry film, and PIPS detector measurements, respectively. Monte Carlo simulations were used for dosimetry. Three prostate cancer (LNCaP, DU145, PC3) and three pancreatic cancer (Capan-1, Panc-1, BxPC-3) cell lines were irradiated by α-particles to the absorbed doses 0, 0.5, 1, and 2 Gy. For reference, cells were irradiated using (137)Cs to the absorbed doses 0, 1, 2, 4, 6, 8, and 10 Gy. Radiation sensitivity was estimated using a tetrazolium salt-based colorimetric assay with absorbance measurements at 450 nm. The relative biological effectiveness for α-particles relative to γ-irradiation at 37% cell survival for the LNCaP, DU145, PC3, Capan-1, Panc-1, and BxPC-3 cells was 7.9 ± 1.7, 8.0 ± 0.8, 7.0 ± 1.1, 12.5 ± 1.6, 9.4 ± 0.9, and 6.2 ± 0.7, respectively. The results show the feasibility of constructing a desktop α-particle irradiator as well as indicate that both prostate and pancreatic cancers are good candidates for further studies of α-particle radioimmunotherapy.

Pancreatic cancer: Disease dynamics, tumor biology and the role of the microenvironment

Pancreatic cancer is known for its propensity to metastasize. Recent studies have challenged the commonly held belief that pancreatic cancer is a stepwise process, where tumor cells disseminate late in primary tumor development. Instead it has been suggested that pancreatic tumor cells may disseminate early and develop independently and in parallel to the primary tumor. Circulating tumor cells can be found in most patients with pancreatic cancer, even in those with localized stage. Also, recent phylogenetic analyses have revealed evidence for a branched evolution where metastatic lineages can develop early in tumor development. In this Review, we discuss current models of pancreatic cancer progression and the importance of the tumor microenvironment, in order to better understand the recalcitrant nature of this disease.