N1 versus N2 and PMN-MDSC: A critical appraisal of current concepts on tumor-associated neutrophils and new directions for human oncology.

Research on tumor-associated neutrophils (TAN) currently surges because of the well-documented strong clinical relevance of tumor-infiltrating neutrophils. This relevance is illustrated by strong correlations between high frequencies of intratumoral neutrophils and poor outcome in the majority of human cancers. Recent high-dimensional analysis of murine neutrophils provides evidence for unexpected plasticity of neutrophils in murine models of cancer and other inflammatory non-malignant diseases. New analysis tools enable deeper insight into the process of neutrophil differentiation and maturation. These technological and scientific developments led to the description of an ever-increasing number of distinct transcriptional states and associated phenotypes in murine models of disease and more recently also in humans. At present, functional validation of these different transcriptional states and potential phenotypes in cancer is lacking. Current functional concepts on neutrophils in cancer rely mainly on the myeloid-derived suppressor cell (MDSC) concept and the dichotomous and simple N1-N2 paradigm. In this manuscript, we review the historic development of those concepts, critically evaluate these concepts against the background of our own work and provide suggestions for a refinement of current concepts in order to facilitate the transition of TAN research from experimental insight to clinical translation.

Pseurotin D Induces Apoptosis through Targeting Redox Sensitive Pathways in Human Lymphoid Leukemia Cells.

Chronic lymphocytic leukemia (CLL) is the most prevalent lymphoid malignancy in many geographical regions of the world. Pseurotin D, a secondary metabolite of fungi, represents a group of bioactive natural products with a newly ascribed range of interesting biological activities. The purpose of this study was to bring new insights into the mechanism behind the effects of pseurotin D on MEC-1 cells as a representative CLL cell line, with a particular focus on selected signaling pathways important in the proliferation of cells and targeting mitochondrial metabolism. Our results showed that pseurotin D was able to significantly inhibit the proliferation of MEC-1 cells and arrested them in the G2/M cell cycle phase. In addition, pseurotin D was able to induce apoptosis. We found that all of these effects were associated with a change in mitochondrial membrane potential and the production of mitochondrial reactive oxygen species (ROS). We showed for the first time that pseurotin D suppresses MEC-1 cell proliferation and induces apoptotic cell death via induction of the collapse of the mitochondria respiratory chain and the ROS-related caspase pathway. Our results show the pseurotins family as promising compounds which could serve as a basis for the development of new compounds in the treatment of lymphoma.

Biomarker responses in earthworm coelomocyte extract - Noninvasively collected sample for pesticide effect assessment.

Earthworms are often used as model organisms in ecotoxicological research because of their natural habitat where they can be exposed to many different pollutants, including pesticides. Since a number of them has to be sacrificed for sample collection, it would be useful to develop non-invasive methods and techniques suitable for the analysis of target parameters. The aim of this study is to determine whether the coelomocyte extract, obtained by the non-invasive method, can be used to measure responses of biochemical biomarkers and to establish if it can be used in assessing the effects of pesticides already known to have a negative impact on the earthworms. In the present study Eisenia andrei earthworms were exposed for 48 h to organophosphates dimethoate and pirimiphos-methyl using the filter paper contact test. Following exposure, coelomocyte extracts were prepared and acetylcholinesterase (AChE) and carboxylesterase (CES) activities were measured. The percentage of inhibition of the measured enzymes in the coelomocyte extract was compared with the inhibition of the same enzyme activities in the samples obtained from the whole body homogenate. AChE and CES inhibition was observed at all concentrations for both pesticides in different types of samples. Compared to the coelomocyte extract, the level of AChE inhibition was slightly stronger in the whole body homogenate. Inhibition of CES at the same concentrations in different types of samples did not always coincide, especially in the case of dimethoate, however significant inhibition of CES in coelomocyte extract was recorded. This study indicates the possibility of using the coelomocyte extract for measurement of biochemical biomarkers and assessment of pesticide effects.

Acute toxicity of selenate and selenite and their impacts on oxidative status, efflux pump activity, cellular and genetic parameters in earthworm Eisenia andrei.

Selenium (Se) is an essential element for humans, animals, and certain lower plants, but can be toxic at high concentration. Even though Se is potentially toxic, little information is available about the effects of Se on soil animals. The aim of this study was to assess the impact of different concentrations of two Se forms, selenate and selenite, on earthworm Eisenia andrei. In order to obtain comprehensive overview on the Se effects, different parameters were measured. Namely, acute toxicity, apoptosis, efflux pump activity, different enzymatic and non-enzymatic biomarkers (acetylcholinesterase, carboxylesterase, glutathione S-transferase, catalase, glutathione reductase and superoxide dismutase activities, lipid peroxidation level and GSH/GSSG ratio) and expression of genes involved in oxidative and immune response have been investigated. Additionally, measurement of metallothioneins concentration and concentration of Se in exposed earthworms has been also performed. The assessment of acute toxicity showed a greater sensitivity of E. andrei to selenite exposure, whereas Se concentration measurements in earthworms showed higher accumulation of selenate form. Both Se forms caused inhibition of the efflux pump activity. Decrease in superoxide dismutase activity and increase in lipid peroxidation and glutathione reductase activity indicate that Se has a significant impact on the oxidative status of earthworms. Selenate exposure caused an apoptotic-like cell death in the coelomocytes of exposed earthworms, whereas decreased mRNA levels of stress-related genes and antimicrobial factors were observed upon the exposure to selenite. The obtained data give insight into the effects of two most common forms of Se in soil on the earthworm E. andrei.