Protumorogenic Potential of Pancreatic Adenocarcinoma-Derived Extracellular Vesicles.

Cancer development is a highly complicated process in which tumour growth depends on the development of its vascularization system. To support their own growth, tumour cells significantly modify their microenvironment. One of such modifications inflicted by tumours is stimulation of endothelial cell migration and proliferation.

The role of CD44H molecule in the interactions between human monocytes and pancreatic adenocarcinoma-derived microvesicles.

Introduction: CD44H is a transmembrane molecule important for cell-cell and cell-extracellular matrix interactions. In monocytes, CD44H is implicated in phagocytosis of particles coated by hyaluronan (HA). HA fragments were shown to induce chemokine secretion by monocytes.

Characterization of human gastric adenocarcinoma cell lines established from peritoneal ascites.

The three cell lines, designated as gastric cancer (GC)1401, GC1415 and GC1436 were derived from peritoneal effusions from patients with gastric adenocarcinoma. Cell lines were established in tissue culture and in immunodeficient, non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice. All cell lines were cultured in Dulbecco's modified Eagle's medium supplemented with 5% fetal bovine serum.

Preoperative Neutrophil-Lymphocyte and Lymphocyte-Monocyte Ratios Reflect Immune Cell Population Rearrangement in Resectable Pancreatic Cancer.

Background: Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR) may serve as a simple index of the immune function. The aim of this study was to investigate the prognostic significance of NLR, PLR, and LMR in patients with resectable pancreatic ductal adenocarcinoma (PDAC) and to verify whether such biomarkers are associated with changes in populations of lymphoid cells.

Methods: The prognostic implications of blood count parameters were evaluated in a retrospective cohort of 442 subjects undergoing pancreatic resections for PDAC.

Colorectal cancer-derived microvesicles modulate differentiation of human monocytes to macrophages.

Background: Tumour-derived microvesicles (TMVs) are important players in tumour progression, modulating biological activity of immune cells e.g. lymphocytes, monocytes and macrophages.

Interactions of tumour-derived micro(nano)vesicles with human gastric cancer cells.

Background: Tumour cells release membrane micro(nano)fragments called tumour-derived microvesicles (TMV) that are believed to play an important role in cancer progression. TMV suppress/modify antitumour response of the host, but there is also some evidence for their direct interaction with cancer cells. In cancer patients TMV are present in body fluid and tumour microenvironment.

Interactions of human monocytes with TMVs (tumour-derived microvesicles).

The tumour microenvironment represents a dynamic complex milieu, which includes tumour cells, cells of the immune system and other (cellular and non-cellular) components. The role of these particular 'puzzle pieces' may change substantially due to their mutual interactions. The present review concerns different opinions on interactions that occur between monocytes, tumour cells and TMVs (tumour-derived microvesicles).

Properties of monocytes generated from haematopoietic CD34(+) stem cells from bone marrow of colon cancer patients.

Monocytes exhibit direct and indirect antitumour activities and may be potentially useful for various forms of adoptive cellular immunotherapy of cancer. However, blood is a limited source of them. This study explored whether monocytes can be obtained from bone marrow haematopoietic CD34(+) stem cells of colon cancer patients, using previously described protocol of expansion and differentiation to monocytes of cord blood-derived CD34(+) haematopoietic progenitors.

Interactions of monocyte subpopulations generated from cord blood CD34(+) hematopoietic progenitors with tumor cells: assessment of antitumor potential.

Monocytes and their subsets (CD14(++)CD16(+) and CD14(+)CD16(-)) generated from cord blood CD34(+) progenitor cells were used for determination of their capacity to interact with tumor cells in vitro and in vivo. The studies in vitro included adhesion to human umbilical vein endothelial cells, cytotoxicity, production of toxic mediators: reactive oxygen and nitrogen intermediates (ROI and RNI, respectively), and finally their effect on transplantable human tumor growth in nonobese diabetic severe combined immunodeficient mice. The CD14(++)CD16(+) subset exhibited an increased adherence to human umbilical vein endothelial cells and cytotoxicity toward tumor cells in vitro.

Induction of monocyte antitumor response by human cancer cells transduced with TNF-GFP fusion gene: possible implications for immunotherapy of cancer.

This study was undertaken to determine how human pancreatic cancer (HPC-4) cells transduced with the TNF-GFP fusion gene (TLG) alter the antitumor response of human monocytes in vitro and whether they could act as an antitumor vaccine. In our model, HPC-4 cells were transduced with retroviral vector harboring TLG gene and designated as HPC-4(TLG). The TLG protein expression was confirmed by Western blot and flow cytometry analysis.

Tumour-derived microvesicles contain interleukin-8 and modulate production of chemokines by human monocytes.

Background: Tumour-derived microvesicles (TMVs) may interact with cells of the immune system. Our previous observations indicated that TMVs modulate production of cytokines and reactive oxygen species (ROS) by monocytes. This study was designed to determine the role of TMVs in stimulation of chemokine production by human monocytes.

Blood monocytes stimulate migration of human pancreatic carcinoma cells in vitro: the role of tumour necrosis factor - alpha.

In some types of cancers, tumour-infiltrating monocytes/macrophages (TIM) may be responsible for the formation of an invasive microenvironment in a manner dependent on the secretion of soluble mediators such as tumour necrosis factor-alpha (TNF). Human pancreatic carcinoma (HPC-4) cells are able to induce TNF production by monocytes. Here, the effect of human peripheral blood monocytes, precursors of TIM, on the motility of co-cultured HPC-4 cells, was directly analysed in vitro.

Biological activity of dendritic cells generated from cord blood CD34+ hematopoietic progenitors in IL-7- and IL-13-conditioned cultures.

Introduction: Dendritic cells (DCs) are required for initiation of the immune response and may therefore be used for the production of cancer vaccines. As mature DCs (mDCs) are the most potent antigen-presenting cells, there is increasing interest in generating them ex vivo. The present study was designed to obtain mDCs from CD34+ hematopoietic progenitors by culturing them in different media.

Human monocytes both enhance and inhibit the growth of human pancreatic cancer in SCID mice.

Background: Monocytes/macrophages exhibit antitumour potential, but clinicopathological evidence suggests that they may both inhibit and enhance tumour growth. The purpose of this study was to determine the effect of monocytes on the growth of human pancreatic cancer (HPC-4) in severe combined immunodeficient (SCID) mice.

Materials And Methods: Freshly isolated human monocytes or CD14+ cells from cocultures with tumour cells were coengrafted, at various ratios, with HPC-4 cells into SCID mice.

Expansion and differentiation of CD14+CD16(-) and CD14+ +CD16+ human monocyte subsets from cord blood CD34+ hematopoietic progenitors.

To determine whether monocytes can be generated from CD34+ hematopoietic progenitors in large numbers, cord blood CD34+ cells were first expanded for 3-10 days in X-VIVO 10 medium supplemented with FCS, stem cell factor (SCF), thrombopoietin (TPO), and Flt-3 Ligand (Flt-3L), and then differentiated in IMDM medium supplemented with FCS, SCF, Flt-3L, IL-3 and M-CSF for 7-14 days. These two step cultures resulted in up to a 600-fold mean increase of total CD14+ cells. Using this approach, two subpopulations of monocytes were obtained: CD14+CD16(-) and CD14++CD16+ occurring at 2:1 ratio.

Involvement of pattern recognition receptors in the induction of cytokines and reactive oxygen intermediates production by human monocytes/macrophages stimulated with tumour cells.

Background: Some ligands of pattern recognition receptors (PRR) are present on tumour cells. The role of PRR in signalling for cytokine and reactive oxygen intermediates (ROI) production by monocytes and monocyte-derived macrophages (MDM) stimulated with tumour cells was studied.

Materials And Methods: Monocytes/MDM were pretreated with PRR ligands or anti-PRR monoclonal antibodies (mAbs) and stimulated with tumour cells.

Induction of intracellular cytokine production in human monocytes/macrophages stimulated with ligands of pattern recognition receptors.

Objective: This study addressed the role of the pattern recognition receptors (PRR), which recognize different molecular structures present on microorganisms, apoptotic, senescent and tumor cells, in the stimulation of human monocyte and monocyte-derived macrophages (MDM) for the production of intracellular cytokines.

Materials And Methods: Monocytes and MDM were stimulated with different ligands of scavenger receptors (SR) and mannose receptor (MR). Production of intracellular cytokines: tumor necrosis factor alpha (TNF alpha), interleukin 10 and 12 (IL-10, IL-12) was determined by flow cytometry following staining with anti-cytokine monoclonal antibodies (mAbs).

Tumor cell-induced deactivation of human monocytes.

Although blood monocytes exhibit significant cytotoxic activity against tumor cells, the function of tumor infiltrating macrophages (TIM) is depressed in cancer patients. This study addresses the question of how the antitumor response of human monocytes, assessed by production of cytokines (tumor necrosis factor alpha, TNF; IL-10; IL-12p40) and cytotoxicity, is altered by exposure to cancer cells. Tumor cell--pre-exposed monocytes restimulated with tumor cells showed significantly decreased production of TNF, IL-12, increased IL-10 (mRNA and release) and inhibition of IL-1 receptor-associated kinase-1 (IRAK-1) expression.

Immunophenotypic changes and induction of apoptosis of monocytes and tumour cells during their interactions in vitro.

The in vitro model of tumour infiltrating macrophages (TIM)-tumour interactions in which monocytes and monocyte-derived macrophages (MDM) are cultured with cancer cells was used to assess immunophenotypic changes of interacting cells. Following short cocultures, monocytes, MDM and tumour cells were sorted out by FACS and the expression of several determinants was evaluated. Monocytes showed the induction of CD44v6 and v7/8, and up-regulation of CD16 (Fc gamma RIII), CD54 (ICAM-1), CD68 (macrophage maturation marker) and CD86 (costimulatory molecule B7.

Cross-talk between human monocytes and cancer cells during reactive oxygen intermediates generation: the essential role of hyaluronan.

Human monocytes exhibit considerable cytocidal activity against tumor (but not normal cells) associated, at least partly, with the generation of reactive oxygen intermediates (ROIs). The present study examined the role of surface determinants and hyaluronan (HA) in the induction of ROI production by human monocytes stimulated with cancer cells, as measured by luminol-enhanced chemiluminescence (CL). The inhibitory effect of monoclonal antibodies (MAbs) indicated the engagement of CD18, CD29 and CD44 adhesion molecules.

Demonstration of iNOS-mRNA and iNOS in human monocytes stimulated with cancer cells in vitro.

Synthesis and localization of inducible nitric oxide synthase mRNA (iNOS-mRNA) and iNOS protein in the cultures of human monocytes (Mphi) and colon carcinoma cell line (DeTa) that resulted in nitric oxide (NO) synthesis has been studied. The iNOS-mRNA was observed around the sixth hour of culture and peaked at the twelfth hour. The iNOS-mRNA, as determined by the in situ hybridization and iNOS protein, as detected by staining with specific anti-iNOS monoclonal antibodies, were observed preferentially in the cytoplasm of some Mphi, but not in cancer cells.

Induction of reactive oxygen intermediates in human monocytes by tumour cells and their role in spontaneous monocyte cytotoxicity.

The present study examined the ability of human monocytes to produce reactive oxygen intermediates after a contact with tumour cells. Monocytes generated oxygen radicals, as measured by luminol-enhanced chemiluminescence and superoxide anion production, after stimulation with the tumour, but not with untransformed, cells. The use of specific oxygen radical scavengers and inhibitors, superoxide dismutase, catalase, dimethyl sulphoxide and deferoxamine as well as the myeloperoxidase inhibitor 4-aminobenzoic acid hydrazide, indicated that chemiluminescence was dependent on the production of superoxide anion and hydroxyl radical and the presence of myeloperoxidase.

Involvement of protein kinases in signalling for nitric oxide (NO) and tumour necrosis factor alpha (TNF) production by monocytes stimulated with colorectal DeTa cancer cells: the lack of evidence for the role of TNF in the regulation of NO production.

Kinases that are involved in NO and TNF production by human monocytes (MO) stimulated by colorectal cancer (DeTa) cells and effects of exogenous and endogenously synthesized TNF on NO induction were studied. The results based on the use of various inhibitors of protein kinases suggest that different signalling pathways operate in MO during induction of TNF and NO release after stimulation by DeTa cells. Stimulation of NO production required at least PTK, PKC and PKA, but only PTK and PKC were engaged in signal transduction for TNF production.

Cytokine production in transient hypogammaglobulinemia and isolated IgA deficiency.

Background: Transient hypogammaglobulinemia of infancy and isolated IgA deficiency are characterized by normal numbers of circulating B lymphocytes. It is likely that no single abnormality, but rather different factors, may be relevant for the delayed onset of IgG synthesis in transient hypogammaglobulinemia or for the differentiation defect of B cells in IgA deficiency. These factors may include defective production of cytokines or an abnormal response of B cells to various mediators.

Gastroprotective activity of melatonin and its precursor, L-tryptophan, against stress-induced and ischaemia-induced lesions is mediated by scavenge of oxygen radicals.

Background: Melatonin, a pineal hormone that is biosynthesized from L-tryptophan, is known to scavenge oxygen free radicals and to be present in the gut, but little is known about the role of this hormone and its precursor, L-tryptophan, in protecting the gastric mucosa from damage accompanied by increase in the generation of oxygen radicals.

Methods: This study was designed to determine the effects of melatonin and L-tryptophan on the formation of acute gastric lesions induced by stress and ischaemia reperfusion and, for comparison, by topical irritants such as 100% ethanol or acidified acetylsalicylic acid.

Results: It was found that pretreatment with melatonin in doses ranging from 1.