Targeting dendritic cells in pancreatic ductal adenocarcinoma

Dendritic cells (DC) are an integral part of the tumor microenvironment. Pancreatic cancer is characterized by reduced number and function of DCs, which impacts antigen presentation and contributes to immune tolerance. Recent data suggest that exosomes can mediate communication between pancreatic cancer cells and DCs. Furthermore, levels of DCs may serve as prognostic factors. There is also growing evidence for the effectiveness of vaccination with DCs pulsed with tumor antigens to initiate adaptive cytolytic immune responses via T cells. Most experience with DC-based vaccination has been gathered for MUC1 and WT1 antigens, where clinical studies in advanced pancreatic cancer have provided encouraging results. In this review, we highlight the role of DC in the course, prognosis and treatment of pancreatic cancer

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

Pancreatic cancer stroma : controversies and current insights

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

Radioimmunotherapy-a potential novel tool for pancreatic cancer therapy?

Pancreatic cancer is one of the most severe cancers and is predicted to rise up to the number two cancer killer by 2030. The ineffective treatment options available and that the cancer is silent until very late in its course are the main reasons for the poor outcome of the disease. Surgery is the only curative option but only available for 10-15 % of the patients, but even then many relapse due to metastases. Many new treatments are under way, and one of the promising ones is radioimmunotherapy (RIT). This review includes clinical trials with RIT in pancreatic cancer as well as a review of adverse events observed during treatment of other solid tumors. Additionally, preclinical studies are reviewed with emphasis on effect, adverse events, the tumor targeting as well as isotope function. Four clinical trials with pancreatic cancer have been conducted with positive results, and one phase III trial is underway. The use of RIT in patients with solid tumors has proven to be well tolerated, and the adverse effects are almost exclusively hematological. Multiple targets and isotopes have been evaluated preclinically, alone, or in combination with existing drug options. Smaller tumors have in several studies completely regressed, while larger ones have stabilized or progressed more slowly. Pancreatic cancer is one of the solid tumors where RIT have reached the longest. The tumor heterogeneity will most likely leave room for more than one treatment option, and several aspiring therapies are under way. RIT may become part of multimodality tumor-directed therapy for pancreatic cancer

Epigenetic alterations as biomarkers in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) prognosis remains very poor and has only marginally improved during the last decades. Epigenetic alterations have been the focus of many recent studies and offer valuable options for PDAC detection, prognosis and treatment. DNA methylation, histone modifications and microRNA (miR) level changes can be used as biomarkers. These alterations occur early in carcinogenesis and may be specific for PDAC. Additionally, epigenetic alterations can be analyzed from cell-free DNA, free-circulating nucleosomes or shed tumor cells in blood. High-throughput methods are available for miR and DNA methylation level detection. In particular, multiple promising miR level changes have been discovered. No single epigenetic biomarker that offers a sufficient specificity has been discovered yet, but patterns containing multiple independent biomarkers exist

Prevention of pleural adhesions by bioactive polypeptides - a pilot study.

Objective: Postoperative pleural adhesions lead to major problems in repeated thoracic surgery. To date, no antiadhesive product has been proven clinically effective. Previous studies of differently charged polypeptides, poly-L-lysine (PL) and poly-L-glutamate (PG) have shown promising results reducing postoperative abdominal adhesions in experimental settings. This pilot study examined the possible pleural adhesion prevention by using the PL+PG concept after pleural surgery and its possible effect on key parameters; plasmin activator inhibitor-1 (PAI-1) and tissue growth factor beta 1 (TGFb) in the fibrinolytic process. Methods: A total of 22 male rats were used in the study, one control group (n=10) and one experimental group (n=12). All animals underwent primary pleural surgery, the controls receiving saline in the pleural cavity and the experimental group the PL+PG solution administered by spray. The animals were evaluated on day 7. Macroscopic appearance of adhesions was evaluated by a scoring system. Histology slides of the adhesions and pleural biopsies for evaluation of PAI-1 and TGFb1 were taken on day 7. Results: A significant reduction of adhesions in the PL+PG group (p<0.05) was noted at day 7 both regarding the length and severity of adhesions. There were no significant differences in the concentration of PAI-1 and TGFb1 when comparing the two groups. Conclusions: PL+PG may be used to prevent pleural adhesions. The process of fibrinolysis, and fibrosis was though not affected after PLPG administration

Centrosomal Abnormalities in Pancreatic Cancer : Molecular Mechanisms and Clinical Implications

The centrosome is the main microtubule-organizing center in human cells. It regulates normal cell-cycle progression and cell division. Aberrations in the number, structure and function of centrosomes have been found to drive genomic instability and tumorigenesis. Pancreatic cancer frequently displays centrosomal aberrations. Supernumerary and abnormal centrosomes are observed in the earliest stages of pancreatic tumor development, and the p53 pathway acts as an initial barrier to the proliferation of cells with extra centrosomes. In this review, we summarize recent advances in the understanding of centrosomal aberrations in pancreatic cancer, focusing on regulatory mechanisms and prospects for future anticancer treatment

Analysis of MUC4 Expression in Human Pancreatic Cancer Xenografts in Immunodeficient Mice.

Mucin 4 (MUC4) is a cell surface glycoprotein that is overexpressed in most pancreatic tumors. The aim of the present study was to characterize MUC4 expression in experimental pancreatic cancer in order to clarify the correlation between MUC4 and pancreatic cancer histology in vivo