Magdalena Frydrychowicz

Exosomes - structure, biogenesis and biological role in non-small-cell lung cancer.

Many different cells produce and release membraneous microvesicles (MV) or exosomes into their microenvironment. Exosomes represent a specific subtype of secreted derived vesicles which are defined as homogenous vesicles of 30–100 nm lined by a lipid bilayer, which contain a specific set of proteins, lipids, and nucleic acids. There are clear evidences that they serve as important biological signals messengers and carriers in physiological as well as in pathological processes. Those derived from tumours (tumour‐derived exosomes, TD‐exosomes) function as protumourigenic factors that can mediate intercellular communication in the tumour microenvironment and also contribute to cancer progression. The main functions of exosomes in the cancer microenvironment include the following: promotion of primary cancer growth, stimulation of angiogenesis, activation of stromal fibroblasts, sculpting the cancer ECM, generation of a premetastatic niche and suppression of host immune response. Exosomes have recently emerged as potentially promising diagnostic and prognostic biomarkers in cancer and other diseases. This article is a summary of information about the structure and origin of exosomes and also indicates the importance of exosomes and microRNAs in lung cancer. The role of exosomes in NSCLC is little known, and its explanation requires thorough research.

Oxidative stress-dependent increase in ICAM-1 expression promotes adhesion of colorectal and pancreatic cancers to the senescent peritoneal mesothelium.

Intercellular adhesion molecule‐1 (ICAM‐1) has been implicated in adhesion of colorectal and pancreatic cancer cells (of the SW480 and PSN‐1 line, respectively) to the peritoneal mesothelium. It has been demonstrated that ICAM‐1 expression increases with senescence in some cell types, however, the significance of this phenomenon in the context of malignant dissemination remains elusive. In this report we show that the adherence of SW480 and PSN‐1 cells to senescent human omentum‐derived mesothelial cells (HOMCs) in vitro is greater than to early‐passage cells and that the effect is mediated by ICAM‐1. Senescent HOMCs display increased expression of ICAM‐1 mRNA and cell surface protein. The development of this phenotype is related to increased oxidative stress in senescent cells. The augmented ICAM‐1 expression in HOMCs can be reduced by culturing cells with antioxidants; in contrast, exposure of HOMCs to an oxidant, t‐BHP, leads to cellular senescence and increased ICAM‐1 expression. The effect is partly mediated by activation of p38 MAPK and AP‐1 signaling pathways. Finally, culture of HOMCs in the presence of a strong antioxidant, PBN, significantly reduces the senescence‐associated increase in SW480 and PSN‐1 cancer cell binding. These results indicate that increased oxidative stress and increased expression of ICAM‐1 in senescent HOMCs may facilitate peritoneal adhesion of selected colorectal and pancreatic cancers.

TLR receptors in laryngeal carcinoma - immunophenotypic, molecular and functional studies.

Toll-like receptors (TLRs) have been shown to play crucial role in the recognition of unicellular pathogens. We have shown the expression of three TLRs on tumor cells of human laryngeal carcinoma by means of immunohistochemistry. In the current study we searched presence of TLR1-10 on protein and molecular level in larynx carcinoma cell lines and the impact of respective TLR ligands on TLR expression. Larynx carcinoma cell lines have been used. Cell were subjected to immunocytochemistry. RNA isolated from the cells was tested by RT-PCR. Cells were cultured in the presence of respective TLR ligands. Cells than were harvested and subjected to flow cytometry, using anti TLR1-10 Moabs. The cells were evaluated of membrane and cytoplasmic cell staining. TLR reactivity varied in individual cell lines. RT-PCR allowed to show mRNA for all TLRs tested. After short-term cell culture each cell line exhibited distinct pattern of expression of TLRs following interaction with respective ligand. Cytoplasmic TLR staining had usually higher MFI value than membrane one, but after culture with ligand it became reversed. TLRs 7 and 9 showed highest expression in the majority of tumor cells tested. In conclusion, larynx carcinoma cell lines exhibit rather universal expression of TLRs, both on protein and molecular level. Culture of TLR expressing tumor cells with ligands points out for potential reactivity of tumor cells with TLR agonists, what may have therapeutic implications.

The dual role of Treg in cancer

Regulatory T cells (Tregs) represent a small subpopulation of CD4+ cells. Tregs are characterized by the expression of transcription factor Forkhead box protein 3 (FoxP3), also known as scurfin. Tregs are modulators of adaptive immune responses and play an important role in maintaining tolerance to self‐antigens, providing the suppression associated with tumour microenvironment as well. These immunomodulatory properties are the main reason for the development of numerous therapeutic strategies, designed to inhibit the activity of cancer cells. However, due to Treg subpopulation diversity and its many functional pathways, the role of these cells in the cancer development and progression is still not fully understood.

Regulatory T cells in malignant pleural effusions subsequent to lung carcinoma and their impact on the course of the disease

Tumors exert suppressive effects on the host immune system and tumor progression can be linked to functional impairments of immune cells. Regulatory T cells (Treg) are a subpopulation of T lymphocytes and play a key role in suppressing immune responses against autoimmune diseases and cancer. The aim of the study was to investigate the prevalence of Treg in malignant and benign pleural effusions and to evaluate the relationship between Treg frequency and disease advance. Pleural effusions from 76 patients were subjected to a routine laboratory diagnosis and analyzed by conventional cytology. Biological materials were divided into three groups: malignant pleural effusions with malignant cells, effusions from patients with malignancy but without malignant cells, and non-malignant pleural effusions. The frequency of Treg in malignant pleural effusions was significantly higher compared to non-malignant effusions. In general, the increase in Treg frequency was correlated with a decrease in the percentage of lymphocytes and an increase in T CD4+ and T CD4+ CD25+ cells. The highest percentage of Treg was observed among patients with the most advanced clinical stage of lung cancer in terms of size and location of a primary tumor, T4. A Kaplan-Meier survival analysis showed a statistically significant trend towards an adverse outcome for patients representing higher Treg counts. Overall, our results support the extraordinary potential of Treg control in future anticancer therapy.

Characteristics of Regulatory T cells

Regulatory T cells (Tregs) is heterogenic subpopulation of T cells that is able to suppress function of effector cells during the immune response. Among them are natural (nTreg) and induced Treg (Tr1, Th3, CD4 + CD25 - ). CD25, CD45Ro, CD152, GITR, LAG-3, several adhesion molecules, chemokine receptors as well as Toll-like receptors are present on the surface of Treg. Mechanism of suppression used by nTreg is not completely understood.

The impact of dapagliflozin on glucose excursions related to early proatherogenic derangement in the aortic wall

Introduction Cardiovascular risk in the course of diabetes depends greatly on glycemic variability which is even more significant than chronic hyperglycemia. Optimal management of diabetes involves a multidisciplinary approach focused in particular on decreasing the risk of atherosclerosis. Therefore, our purpose was to evaluate the impact of dapagliflozin on glucose excursions and related proatherogenic changes in the aortic wall. Methods and materials Animal model of type 2 diabetes rich-fat/STZ rats was used. Wistar rats were randomized into 3 groups: dapagliflozin-treated with glucose excursions, placebo-treated with glucose excursions and placebo-treated with stable diabetes. Dapagliflozin was administered once a day, 1 mg/kg, for 8 consecutive weeks. Glucose levels were measured twice a week at fasting and postprandially. The samples of aortas were taken for histopathological and immunochemistry examinations at the end of the experiment. The derangement in the aortic wall and the distribution of CD68+ cells in the aorta were considered early signs of atherosclerosis. Results Dapagliflozin reduced glucose excursion to the level characteristic for stable, well-controlled diabetes. It was related to a significant decrease in histopathological changes which were observed in the placebo-treated rats with glucose variability. Dapagliflozin significantly reduced also the accumulation of CD68+ macrophages in the aortic adventitia. Conclusion Dapagliflozin provides not only mere beneficial regulation of metabolic status with the depletion of glucose variability, but is also helpful in the prevention of early atherosclerosis related to the course of diabetes type 2.

Pleural Macrophages can Promote or Inhibit Apoptosis of Malignant Cells via Humoral Mediators Depending on Intracellular Signaling Pathways

Abstract Macrophages in malignant pleural effusions (MPEs) demonstrate a promalignant phenotype. They release mediators, which are a source of inflammation within the pleura. We established in vitro model proving that pleural macrophages isolated from effusions affect cancer cells in their pro- or anti-apoptotic activity via humoral mediators. Additionally, we measured concentrations of selected transcription factors in cancer cells. Pleural macrophages can affect the apoptosis of cancer cells via intercellular mediators which trigger different signal transductors in cancer cells. The observed effect is connected to the composition of exudate which may vary depending on its origin, either malignant or nonmalignant.

Theeffect of caveolin-1 knockdown on interleukin-1β-inducedchemokine (C-C motif) ligand 2 expression in synovial fluid-derivedfibroblast-like synoviocytes from patients with rheumatoid arthritis

BACKGROUND Rheumatoid arthritis (RA) is a chronic autoimmune disease leading to destructive changes in peripheral joints and their irreversible deformity. The influx of chemoattractant-mediated inflammatory cells to the joints is one of the main features of RA. OBJECTIVES The aim of this study was to investigate the effect of a knockdown of caveolin-1 (CAV1), a known regulator of multiple cell signaling pathways, on chemokine (C-C motif) ligand 2/monocyte chemoattractant protein-1 (CCL2/MCP-1) expression in synovial fluid-derived fibroblast-like synoviocytes (sfd-FLSs) obtained from patients with RA. MATERIAL AND METHODS Primary cell cultures of sfd-FLSs were established from RA synovial fluids. Cells were transiently transfected with small interfering RNA (siRNA) specific for CAV1, and then incubated with interleukin (IL)-1β to induce CCL2 expression. The expression levels of CAV1 and CCL2 were assessed at transcript level, using quantitative polymerase chain reaction (qPCR) and at protein level by enzyme-linked immunosorbent assay (ELISA) and western blotting analysis. RESULTS A transient CAV1 knockdown in sfd-FLSs resulted in a decrease in the IL-1β-induced CCL2 mRNA expression level vs non-transfected cells and cells transfected with non-targeting siRNA. The concentration of secreted CCL2 was not affected significantly. CONCLUSIONS Our study demonstrates that CCL2 expression in sfd-FLSs is CAV1-dependent, but only at transcript level. As the function of CAV1 has not been unequivocally determined, more studies are needed to confirm the role of CAV1 in inflammatory processes related to RA.

Serum alarm antiproteases in systemic sclerosis patients

Alarm antiproteases, i.e. secretory leukocyte protease inhibitor ad elafin, are key mediators in innate immune response and integrate innate and adaptive immunity systems. The aim of the study was to assess clinical significance of serum levels of alarm antiproteases, elafin and secretory leukocyte protease inhibitor (SLPI) in patients with systemic sclerosis (SSc). Twenty-eight patients with SSc, 25 patients with rheumatoid arthritis (RA) and 22 healthy controls were recruited. Serum elafin and SLPI levels were examined using enzyme-linked immunosorbent assay (ELISA). The patients with SSc had significantly increased serum levels of SLPI in comparison with the RA patients and the healthy controls (p<0.01), and the RA patients presented significantly higher serum levels of elafin in comparison with the controls (p=0.003). In the SSc subgroup serum SLPI level negatively correlated with diffusing capacity of the lung for carbon monoxide (DLCO) (r=-0.41, p=0.03) and total lung capacity (r=-0.42, p=0.03). Both alarm antiproteases, elafin and SLPI could be potentially implicated in the pathogenesis of SSc and SLPI may be considered a candidate for serum biomarker of lung involvement in SSc.