Altered histone acetylation patterns in pancreatic cancer cell lines induce subtype‑specific transcriptomic and phenotypical changes

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at advanced tumor stages with chemotherapy as the only treatment option. Transcriptomic analysis has defined a classical and basal‑like PDAC subtype, which are regulated by epigenetic modification. The present study aimed to determine if drug‑induced epigenetic reprogramming of pancreatic cancer cells affects PDAC subtype identity and chemosensitivity. Classical and basal‑like PDAC cell lines PaTu‑S, Capan‑1, Capan‑2, Colo357, PaTu‑T, PANC‑1 and MIAPaCa‑2, were treated for a short (up to 96 h) and long (up to 30 weeks) period with histone acetyltransferase (HAT) and histone deacetylase (HDAC) inhibitors. The cells were analyzed using gene expression approaches, immunoblot analysis, and various cell assays to assess cell characteristics, such as proliferation, colony formation, cell migration and sensitivity to chemotherapeutic drugs. Classical and basal‑like PDAC cell lines showed pronounced epigenetic regulation of subtype‑specific genes through acetylation of lysine 27 on Histone H3 (H3K27ac). Moreover, classical cell lines revealed a significantly decreased expression of HDAC2 and increased total levels of H3K27ac in comparison with the basal‑like cell lines. Following HAT inhibitor treatment, classical cell lines exhibited a loss of epithelial marker gene expression, decreased chemotherapy response gene score and increased cell migration in vitro, indicating a tumor‑promoting phenotype. HDAC inhibitor treatment, however, exerted minimal reprogramming effects in both subtypes. Epigenetic reprogramming of classical and basal‑like tumor cells did not have a major impact on gemcitabine response, although the gemcitabine transporter gene SLC29A1 (solute carrier family 29 member 1) was epigenetically regulated.

ADP-induced platelet aggregation in patients with acute coronary syndrome treated with prasugrel or ticagrelor. Results of the ISAR REACT 5 platelet aggregation substudy

Introduction

The recently published randomized multicenter open label ISAR REACT 5 trial showed that prasugrel was superior to ticagrelor with respect to the composite primary end point of death, myocardial infarction, or stroke at one year after randomization in patients with acute coronary syndrome with planned invasive evaluation. The reasons for this finding are speculative.

Purpose

The aim of this prespecified platelet aggregation substudy was to assess platelet aggregation induced by adenosine-diphosphate (ADP) in patients who received prasugrel or ticagrelor treatment and underwent PCI.

Methods

We assessed all patients who underwent PCI and who had valid ADP-induced platelet aggregation values at hospital admission and at 2–24 hours after administration of prasugrel or ticagrelor loading dose followed by maintenance dose. ADP-induced platelet aggregation values were measured using the Mulitplate Analyzer®. Patients were recruited in the German Heart Center, Munich, Germany or in Klinikum rechts der Isar, Munich, Germany, Technical University of Munich.

Results

A total of 608 patients were analyzed. Patients in the prasugrel group were slightly but significantly older than patients in the ticagrelor group (66,5 years versus 64,6 years, P=0,048). The remaining baseline characteristics did not significantly differ between the two treatment groups. ADP-induced platelet aggregation (median [IQR]) at baseline did not differ between prasgurel- and ticagrelor treated patients (809 [556; 1057] AU x min versus 797 [534–1095] AU x min. At 2–24 hours after study drug administration ADP-induced platelet aggregation was significantly lower in patients who had received prasugrel in comparison to ticagrelor (105 [57–176] AU x min versus 138 [77–207] AU x min (Figure 1).

Conclusion

ADP-induced platelet aggregation was significantly lower in patients who received prasugrel in comparison to patients who received ticagrelor, which could have influenced patients' outcome in the ISAR-REACT 5 trial.

Figure 1

Funding Acknowledgement

Type of funding source: None

Immature platelet fraction is a strong predictor of adverse cardiovascular events in patients with acute coronary syndrome. Results of the ISAR-REACT 5 reticulated platelet substudy

Introduction

Reticulated or immature Platelets are pro-thrombotic RNA-rich young platelets, which have been reported to correlate with adverse events in several pathological settings including coronary artery disease. However, the predictive value of this subgroup of platelets in patients with acute coronary syndrome treated with the potent novel P2Y12 inhibitors prasugrel or ticagrelor has not been investigated yet. Moreover, their role as predictors of major bleeding is unclear.

Purpose

The primary aim of this prespecified reticulated platelet ISAR-REACT-5 substudy was to evaluate the immature platelet fraction (IPF%) in peripheral blood as a predictor of the composite primary endpoint consisting of death, myocardial infarction, or stroke at one year after randomization in patients with acute coronary syndrome.

Methods

IPF was assessed in the first 24h after randomization using a fully automated system and correlated to the incidence of the primary endpoint. All patients with available IPF values were included. The Sysmex system uses two fluorescent dyes to stain platelet RNA and a computer algorithm (Sysmex IPF Master) discriminates immature from mature platelets by the intensity of forward scattered light and fluorescence. The immature platelet fraction is displayed as percentage of the total optical platelet count (IPF%).

Results

IPF values within the first 24h after randomization were available in a total of 506 randomized patients. Baseline characteristics and IPF (median [IQR]) values did not differ between the 2 study groups (IPF: prasugrel 3.9% [2.7–5.8] ticagrelor 3.4% [2.5–5.6] p=0.56). Significantly higher IPF values were observed in patients reaching the primary endpoint (n=55 of 506) independent from the study group (p for interaction= 0.28). ROC-curve analysis revealed a cut-of value of IPF 3.6% for the prediction of death, myocardial infarction or stroke with a Hazard ratio (HR) according to cox-regression analysis of 1.98 (95% CI, 1.15–3.44), P=0.01 (Figure 1A). Interestingly, we also detected a trend for higher major bleedings (BARC 3–5) in patients with elevated IPF values above IPF>4.8% according to ROC-curve analysis (Figure 1B).

Conclusion

IPF was significantly associated with the primary endpoint in the ISAR-REACT 5 substudy independent from the treatment group and therefore is a promising novel biomarker for the prediction of adverse cardiovascular events in patients with acute coronary syndrome.

Figure 1

Funding Acknowledgement

Type of funding source: None

Characteristics of Patients Accepting and Declining Participation in a Transition of Care Service Provided by a Community Pharmacy

Objectives: To identify characteristics of patients who accepted or declined an appointment for a transition of care service provided by an independent community pharmacist and identify the most common reasons patients declined the service. Methods: A transition of care service was offered by a community pharmacy to patients discharged to home from the cardiac unit of a local hospital. The community pharmacist approached patients prior to discharge for recruitment into the service. Outcomes included service acceptance rate, LACE score at discharge, readmission risk category, age, gender, geographic home location, and reason for refusing the service. Descriptive statistics and logistic regression were used to compare characteristics between those who accepted or declined the service. Reasons for decline were assessed using content analysis. Results: Of the 87 patients that were included in the analysis, 21 patients received the transitions of care service (24.1%). None of the characteristics were found to be statistically significant between patients who received or declined the service. Patients at a moderate risk for readmission seemed more likely to accept the pharmacist-run appointment than those at high risk (27.9% vs 15.3%; P = 0.29). Of the 66 patients who declined, 51 gave a reason (77.3%). Thirty-nine patients saw no benefit (76.5%), five patients had perceived barriers (10%), and seven patients gave reasons that fell into both categories (13.5%). Conclusions: This evaluation did not find a statistically significant difference in characteristics between those patients who accepted or declined participation in a pharmacist-run transition of care service. Patients may be less likely to accept pharmacist-run transition of care appointments primarily due to no perceived benefits. To increase participation, we need to understand the patient’s health beliefs, educate patients on pharmacy services, and implement changes to recruit potential patients. Conflict of Interest Disclosures: The authors have no actual or potential conflict of interest in relation to this evaluation. This evaluation was presented as a poster presentation at American Pharmacists Association Annual Meeting and Exposition, March 4-7, 2016 and at the Pharmacy Society of Wisconsin Education Conference, April 5-6, 2016. This evaluation was presented as a podium presentation at Great Lakes Residency Conference, April 27-29, 2016.   Type: Original Research

Microglial cell activation in demyelinating canine distemper lesions

Microglia cells are the principal immune effector elements of the brain responding to any pathological event. To elucidate the possible role of microglia in initial non-inflammatory demyelination in canine distemper virus (CDV) infection, microglia from experimentally CDV infected dogs were isolated ex vivo by density gradient centrifugation and characterized immunophenotypically and functionally using flow cytometry. Results from dogs with demyelinating lesions were compared to results from recovered dogs and two healthy controls. CDV antigen could be detected in microglia of dogs with histopathologically confirmed demyelination. Microglia of these dogs showed marked upregulation of the surface molecules CD18, CD11b, CD11c, CD1c, MHC class I and MHC class II and a tendency for increased expression intensity of ICAM-1 (CD54), B7-1 (CD80), B7-2 (CD86), whereas no increased expression was found for CD44 and CD45. Functionally, microglia exhibited distinctly enhanced phagocytosis and generation of reactive oxygen species (ROS). It was concluded that in CDV infection, there is a clear association between microglial activation and demyelination. This strongly suggests that microglia contribute to acute myelin destruction in distemper.