Modes of Interactions with DNA/HSA Biomolecules and Comparative Cytotoxic Studies of Newly Synthesized Mononuclear Zinc(II) and Heteronuclear Platinum(II)/Zinc(II) Complexes toward Colorectal Cancer Cells.

A series of mono- and heteronuclear platinum(II) and zinc(II) complexes with 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine ligand were synthesized and characterized. The DNA and protein binding properties of [ZnCl2(terpytBu)] (C1), [{cis-PtCl(NH3)2(µ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C2), [{trans-PtCl(NH3)2(µ-pyrazine)ZnCl(terpytBu)}](ClO4)2 (C3), [{cis-PtCl(NH3)2(µ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C4) and [{trans-PtCl(NH3)2(µ-4,4'-bipyridyl)ZnCl(terpytBu)}](CIO4)2 (C5) (where terpytBu = 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine), were investigated by electronic absorption, fluorescence spectroscopic, and molecular docking methods. Complexes featuring transplatin exhibited lower Kb and Ksv constant values compared to cisplatin analogs. The lowest Ksv value belonged to complex C1, while C4 exhibited the highest. Molecular docking studies reveal that the binding of complex C1 to DNA is due to van der Waals forces, while that of C2-C5 is due to conventional hydrogen bonds and van der Waals forces. The tested complexes exhibited variable cytotoxicity toward mouse colorectal carcinoma (CT26), human colorectal carcinoma (HCT116 and SW480), and non-cancerous mouse mesenchymal stem cells (mMSC). Particularly, the mononuclear C1 complex showed pronounced selectivity toward cancer cells over non-cancerous mMSC. The C1 complex notably induced apoptosis in CT26 cells, effectively arrested the cell cycle in the G0/G1 phase, and selectively down-regulated Cyclin D.

Crosstalk between mesenchymal stem cells and T regulatory cells is crucially important for the attenuation of acute liver injury.

One of the therapeutic options for the treatment of fulminant hepatitis is repopulation of intrahepatic regulatory cells because their pool is significantly reduced during acute liver failure. Although it is known that mesenchymal stem cells (MSCs), which have beneficent effects in the therapy of fulminant hepatitis, may promote expansion of regulatory T cells (Tregs) and regulatory B cells (Bregs), the role of these regulatory cells in MSC-mediated attenuation of acute liver injury is unknown. Herewith, we described the molecular mechanisms involved in the crosstalk between MSCs and liver regulatory cells and analyzed the potential of MSC-based therapy for the expansion of intrahepatic regulatory cells in mouse model of acute liver failure. MSC-dependent attenuation of α-galactosylceramide (α-GalCer)-induced acute liver injury in mice was accompanied with an increased presence of interleukin (IL) 10-producing CD4+ CD25+ forkhead box P3+ Tregs and IL10- and transforming growth factor ß-producing marginal zone-like Bregs in the liver. Depletion of Bregs did not alter MSC-based alleviation of acute liver failure, whereas depletion of Tregs completely abrogated hepatoprotective effects of MSCs and inhibited their capacity to attenuate hepatotoxicity of liver natural killer T cells (NKTs), indicating that Tregs, and not Bregs, were critically involved in MSC-based modulation of acute liver inflammation. MSCs, in a paracrine, indoleamine 2,3-dioxygenase-dependent manner, significantly increased the capacity of Tregs to produce immunosuppressive IL10 and to suppress hepatotoxicity of liver NKTs. Accordingly, adoptive transfer of MSC-primed Tregs resulted in the complete attenuation of α-GalCer-induced acute liver failure. In conclusion, our findings highlighted the crucial importance of Tregs for MSC-based attenuation of acute liver failure and indicated the significance of MSC-mediated priming of Tregs as a new therapeutic approach in Treg-based therapy of acute liver injury. Liver Transplantation 24 687-702 2018 AASLD.

Ethical and Safety Issues of Stem Cell-Based Therapy.

Results obtained from completed and on-going clinical studies indicate huge therapeutic potential of stem cell-based therapy in the treatment of degenerative, autoimmune and genetic disorders. However, clinical application of stem cells raises numerous ethical and safety concerns. In this review, we provide an overview of the most important ethical issues in stem cell therapy, as a contribution to the controversial debate about their clinical usage in regenerative and transplantation medicine. We describe ethical challenges regarding human embryonic stem cell (hESC) research, emphasizing that ethical dilemma involving the destruction of a human embryo is a major factor that may have limited the development of hESC-based clinical therapies. With previous derivation of induced pluripotent stem cells (iPSCs) this problem has been overcome, however current perspectives regarding clinical translation of iPSCs still remain. Unlimited differentiation potential of iPSCs which can be used in human reproductive cloning, as a risk for generation of genetically engineered human embryos and human-animal chimeras, is major ethical issue, while undesired differentiation and malignant transformation are major safety issues. Although clinical application of mesenchymal stem cells (MSCs) has shown beneficial effects in the therapy of autoimmune and chronic inflammatory diseases, the ability to promote tumor growth and metastasis and overestimated therapeutic potential of MSCs still provide concerns for the field of regenerative medicine. This review offers stem cell scientists, clinicians and patient's useful information and could be used as a starting point for more in-depth analysis of ethical and safety issues related to clinical application of stem cells.

In vitro and in vivo anti-tumor effects of selected platinum(IV) and dinuclear platinum(II) complexes against lung cancer cells.

In the present study, cytotoxic effects of cisplatin, the most usually used chemotherapeutic agent, were compared with new designed platinum(IV) ([PtCl4(en)] (en = ethylenediamine) and [PtCl4(dach)]) (dach = (±)-trans-1,2-diaminocyclohexane) and platinum(II) complexes ([{trans-Pt(NH3)2Cl}2(µ-pyrazine)](ClO4)2 (Pt1), [{trans-Pt(NH3)2Cl}2(µ-4,4'-bipyridyl)](ClO4)2DMF(Pt2),[{trans-Pt(NH3)2Cl}2(µ-1,2-bis(4pyridyl)ethane)](ClO4)2 (Pt3)), in vitro and in vivo against human and murine lung cancer cells, to determine anti-tumor potential of newly synthesized platinum-based drugs in the therapy of lung cancer. Results obtained by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], Lactate dehydrogenase and Annexin V/Propidium Iodide assays showed that, among all tested complexes, [PtCl4(en)] had the highest cytotoxicity against human and murine lung carcinoma cells in vitro. [PtCl4(en)] showed significantly higher cytotoxicity then cisplatin in all tested concentrations, mainly by inducing apoptosis in lung cancer cells. [PtCl4(en)] was well tolerated in vivo. Clinical signs of [PtCl4(en)]-induced toxicity, such as changes in food, water consumption or body weight, nephrotoxicity or hepatotoxicity was not observed in [PtCl4(en)]-treated mice. [PtCl4(en)] managed to increase presence of CD45+ leukocytes, including F4/80+ macrophages, CD11c+ dendritic cells, CD4+ helper and CD8+ cytotoxic T cells (CTLs) in the lungs, cytotoxic NK, NKT and CTLs in the spleens of tumor bearing mice, resulting with reduction of metastatic lesions in the lungs, indicating its potential to stimulate anti-tumor immune response in vivo. Due to its anti-tumor cytotoxicity, biocompatibility, and potential for stimulation of anti-tumor immune response, [PtCl4(en)] may be a good candidate for further testing in the field of medicinal chemistry.

Gal-3 regulates the capacity of dendritic cells to promote NKT-cell-induced liver injury.

Galectin-3 (Gal-3), an endogenous lectin, exhibits pro- and anti-inflammatory effects in various disease conditions. In order to explore the role of Gal-3 in NKT-cell-dependent pathology, we induced hepatitis in C57BL/6 WT and Gal-3-deficient mice by using specific ligand for NKT cells: α-galactosylceramide, glycolipid Ag presented by CD1d. The injection of α-galactosylceramide significantly enhanced expression of Gal-3 in liver NKT and dendritic cells (DCs). Genetic deletion or selective inhibition of Gal-3 (induced by Gal-3-inhibitor TD139) abrogated the susceptibility to NKT-cell-dependent hepatitis. Blood levels of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-12) and their production by liver DCs and NKT cells were also downregulated. Genetic deletion or selective inhibition of Gal-3 alleviated influx of inflammatory CD11c(+) CD11b(+) DCs in the liver and favored tolerogenic phenotype and IL-10 production of liver NKT and DCs. Deletion of Gal-3 attenuated the capacity of DCs to support liver damage in the passive transfer experiments and to produce pro-inflammatory cytokines in vitro. Gal-3-deficient DCs failed to optimally stimulate production of pro-inflammatory cytokines in NKT cells, in vitro and in vivo. In conclusion, Gal-3 regulates the capacity of DCs to support NKT-cell-mediated liver injury, playing an important pro-inflammatory role in acute liver injury.

The role of Interleukin 1 receptor antagonist in mesenchymal stem cell-based tissue repair and regeneration.

Interleukin (IL)-1 receptor antagonist (IL-1Ra), a naturally occurring antagonist of IL-1α/IL-1ß signaling pathways, has been attributed to the immunosuppressive effects of mesenchymal stem cells (MSCs). MSCs, in IL-1Ra-dependent manner, suppressed production of IL-1ß in dermal macrophages, induced their polarization in anti-inflammatory M2 phenotype, attenuated antigen-presenting properties of dendritic cells (DCs), and promoted expansion of immunosuppressive T regulatory cells in the skin, which resulted in enhanced repair of the nonhealing wounds. Reduced activation of inflammasome and suppressed production of IL-1ß in macrophages were mainly responsible for beneficial effects of MSC-derived IL-1Ra in alleviation of acute lung injury, dry eye syndrome, and corneal injury. Through the production of IL-1Ra, MSCs reduced migration of DCs to the draining lymph nodes and attenuated generation of inflammatory Th1 and Th17 cells that resulted in alleviation of fulminant hepatitis and rheumatoid arthritis. MSCs, in IL-1Ra-dependent manner, reduced liver fibrosis by suppressing production of Type I collagen in hepatic stellate cells. IL-1Ra was, at least partially, responsible for enhanced proliferation of hepatocytes and chondrocytes in MSC-treated animals with partial hepatectomy and osteoarthritis. Despite of these beneficial effects, IL-1Ra-dependent inhibition of IL-1α/IL-1ß-signaling significantly increased risk of infections. Therefore, future experimental and clinical studies should delineate potential side effects of MSC-derived IL-1Ra before IL-1Ra-overexpressing MSCs could be used as a potentially new therapeutic agent for the treatment of acute and chronic inflammatory diseases.

The Effects of Mesenchymal Stem Cells on Antimelanoma Immunity Depend on the Timing of Their Administration.

There is still a lively debate about whether mesenchymal stem cells (MSCs) promote or suppress antitumor immune response. Although several possible explanations have been proposed, including different numbers of injected and engrafted MSCs, heterogeneity in phenotype, and function of tumor cells, the exact molecular mechanisms responsible for opposite effects of MSCs in modulation of antitumor immunity are still unknown. Herewith, we used a B16F10 murine melanoma model to investigate whether timing of MSC administration in tumor-bearing mice was crucially important for their effects on antitumor immunity. MSCs, intravenously injected 24 h after melanoma induction (B16F10+MSC1d-treated mice), significantly enhanced natural killer (NK) and T cell-driven antitumor immunity, suppressed tumor growth, and improved survival of melanoma-bearing animals. Significantly higher plasma levels of antitumorigenic cytokines (TNF-α and IFN-γ), remarkably lower plasma levels of immunosuppressive cytokines (TGF-ß and IL-10), and a significantly higher number of tumor-infiltrating, IFN-γ-producing, FasL- and granzyme B-expressing NK cells, IL-17-producing CD4+Th17 cells, IFN-γ- and TNF-α-producing CD4+Th1 cells, and CD8+cytotoxic T lymphocytes (CTLs) were observed in B16F10+MSC1d-treated mice. On the contrary, MSCs, injected 14 days after melanoma induction (B16F10+MSC14d-treated mice), promoted tumor growth by suppressing antigen-presenting properties of tumor-infiltrating dendritic cells (DCs) and macrophages and by reducing tumoricidal capacity of NK cells and T lymphocytes. Significantly higher plasma levels of TGF-ß and IL-10, remarkably lower plasma levels of TNF-α and IFN-γ, and significantly reduced number of tumor-infiltrating, I-A-expressing, and IL-12-producing macrophages, CD80- and I-A-expressing DCs, granzyme B-expressing CTLs and NK cells, IFN-γ- and IL-17-producing CTLs, CD4+Th1, and Th17 cells were observed in B16F10+MSC14d-treated animals. In summing up, the timing of MSC administration into the tumor microenvironment was crucially important for MSC-dependent modulation of antimelanoma immunity. MSCs transplanted during the initial phase of melanoma growth exerted tumor-suppressive effect, while MSCs injected during the progressive stage of melanoma development suppressed antitumor immunity and enhanced tumor expansion.

Molecular and Cellular Mechanisms Responsible for Beneficial Effects of Mesenchymal Stem Cell-Derived Product "Exo-d-MAPPS" in Attenuation of Chronic Airway Inflammation.

Mesenchymal stem cells (MSCs), due to their potential for differentiation into alveolar epithelial cells and their immunosuppressive characteristics, are considered a new therapeutic agent in cell-based therapy of inflammatory lung disorders, including chronic obstructive pulmonary disease (COPD). Since most of the MSC-mediated beneficent effects were the consequence of their paracrine action, herewith, we investigated the effects of a newly designed MSC-derived product "Exosome-derived Multiple Allogeneic Protein Paracrine Signaling (Exo-d-MAPPS)" in the attenuation of chronic airway inflammation by using an animal model of COPD (induced by chronic exposure to cigarette smoke (CS)) and clinical data obtained from Exo-d-MAPPS-treated COPD patients. Exo-d-MAPPS contains a high concentration of immunomodulatory factors which are capable of attenuating chronic airway inflammation, including soluble TNF receptors I and II, IL-1 receptor antagonist, and soluble receptor for advanced glycation end products. Accordingly, Exo-d-MAPPS significantly improved respiratory function, downregulated serum levels of inflammatory cytokines (TNF-α, IL-1ß, IL-12, and IFN-γ), increased serum concentration of immunosuppressive IL-10, and attenuated chronic airway inflammation in CS-exposed mice. The cellular makeup of the lungs revealed that Exo-d-MAPPS treatment attenuated the production of inflammatory cytokines in lung-infiltrated macrophages, neutrophils, and natural killer and natural killer T cells and alleviated the antigen-presenting properties of lung-infiltrated macrophages and dendritic cells (DCs). Additionally, Exo-d-MAPPS promoted the expansion of immunosuppressive IL-10-producing alternatively activated macrophages, regulatory DCs, and CD4+FoxP3+T regulatory cells in inflamed lungs which resulted in the attenuation of chronic airway inflammation. In a similar manner, as it was observed in an animal model, Exo-d-MAPPS treatment significantly improved the pulmonary status and quality of life of COPD patients. Importantly, Exo-d-MAPPS was well tolerated since none of the 30 COPD patients reported any adverse effects after Exo-d-MAPPS administration. In summing up, we believe that Exo-d-MAPPS could be considered a potentially new therapeutic agent in the treatment of chronic inflammatory lung diseases whose efficacy should be further explored in large clinical trials.

Therapeutic Potential of Mesenchymal Stem Cells and Their Secretome in the Treatment of Glaucoma.

Glaucoma represents a group of progressive optic neuropathies characterized by gradual loss of retinal ganglion cells (RGCs), the neurons that conduct visual information from the retina to the brain. Elevated intraocular pressure (IOP) is considered the main reason for enhanced apoptosis of RGCs in glaucoma. Currently used therapeutic agents are not able to repopulate and/or regenerate injured RGCs and, therefore, are ineffective in most patients with advanced glaucoma. Accordingly, several new therapeutic approaches, including stem cell-based therapy, have been explored for the glaucoma treatment. In this review article, we emphasized current knowledge regarding molecular and cellular mechanisms responsible for beneficial effects of mesenchymal stem cells (MSCs) and their secretome in the treatment of glaucoma. MSCs produce neurotrophins and in an exosome-dependent manner supply injured RGCs with growth factors enhancing their survival and regeneration. Additionally, MSCs are able to generate functional RGC-like cells and induce proliferation of retinal stem cells. By supporting integrity of trabecular meshwork, transplanted MSCs alleviate IOP resulting in reduced loss of RGCs. Moreover, MSCs are able to attenuate T cell-driven retinal inflammation providing protection to the injured retinal tissue. In summing up, due to their capacity for neuroprotection and immunomodulation, MSCs and their secretome could be explored in upcoming clinical studies as new therapeutic agents for glaucoma treatment.

Mesenchymal stem cell-based therapy of osteoarthritis: Current knowledge and future perspectives.

Osteoarthritis (OA) is a chronic, prevalent, debilitating joint disease characterized by progressive cartilage degradation, subchondral bone remodeling, bone marrow lesions, meniscal damage, and synovitis. Innate immune cells (natural killer cells, macrophages, and mast cells) play the most important pathogenic role in the early inflammatory response, while cells of adaptive immunity (CD4 + Th1 lymphocytes and antibody producing B cells) significantly contribute to the development of chronic, relapsing course of inflammation in OA patients. Conventional therapy for OA is directed toward symptomatic treatment, mainly pain management, and is not able to promote regeneration of degenerated cartilage or to attenuate joint inflammation. Since articular cartilage, intra-articular ligaments, and menisci have no ability to heal, regeneration of these tissues remains one of the most important goals of new therapeutic approaches used for OA treatment. Due to their capacity for differentiation into chondrocytes and due to their immunomodulatory properties, mesenchymal stem cells (MSCs) have been the most extensively explored as new therapeutic agents in the cell-based therapy of OA. Simple acquisition, rapid proliferation, maintenance of differentiation potential after repeated passages in vitro, minor immunological rejection due to the low surface expression of major histocompatibility complex antigens, efficient engraftment and long-term coexistence in the host are the main characteristics of MSCs that enable their therapeutic use in OA. In this review article, we emphasized current knowledge and future perspectives regarding molecular and cellular mechanisms responsible for beneficial effects of autologous and allogeneic MSCs in the treatment of OA.

Galectin 3 protects from cisplatin-induced acute kidney injury by promoting TLR-2-dependent activation of IDO1/Kynurenine pathway in renal DCs.

Strategies targeting cross-talk between immunosuppressive renal dendritic cells (DCs) and T regulatory cells (Tregs) may be effective in treating cisplatin (CDDP)-induced acute kidney injury (AKI). Galectin 3 (Gal-3), expressed on renal DCs, is known as a crucial regulator of immune response in the kidneys. In this study, we investigated the role of Gal-3 for DCs-mediated expansion of Tregs in the attenuation of CDDP-induced AKI. Methods: AKI was induced in CDDP-treated wild type (WT) C57BL/6 and Gal-3 deficient (Gal-3-/-) mice. Biochemical, histological analysis, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, real-time PCR, magnetic cell sorting, flow cytometry and intracellular staining of renal-infiltrated immune cells were used to determine the differences between CDDP-treated WT and Gal-3-/- mice. Newly synthesized selective inhibitor of Gal-3 (Davanat) was used for pharmacological inhibition of Gal-3. Recombinant Gal-3 was used to demonstrate the effects of exogenously administered soluble Gal-3 on AKI progression. Pam3CSK4 was used for activation of Toll-like receptor (TLR)-2 in DCs. Cyclophosphamide or anti-CD25 antibody were used for the depletion of Tregs. 1-Methyl Tryptophan (1-MT) was used for pharmacological inhibition of Indoleamine 2,3-dioxygenase-1 (IDO1) in TLR-2-primed DCs which were afterwards used in passive transfer experiments. Results: CDDP-induced nephrotoxicity was significantly more aggravated in Gal-3-/- mice. Significantly reduced number of immunosuppressive TLR-2 and IDO1-expressing renal DCs, lower serum levels of KYN, decreased presence of IL-10-producing Tregs and significantly higher number of inflammatory IFN-γ and IL-17-producing neutrophils, Th1 and Th17 cells were observed in the CDDP-injured kidneys of Gal-3-/- mice. Pharmacological inhibitor of Gal-3 aggravated CDDP-induced AKI in WT animals while recombinant Gal-3 attenuated renal injury and inflammation in CDDP-treated Gal-3-/- mice. CDDP-induced apoptosis, driven by Bax and caspase-3, was aggravated in Gal-3-/- animals and in WT mice that received Gal-3 inhibitor (CDDP+Davanat-treated mice). Recombinant Gal-3 managed to completely attenuate CDDP-induced apoptosis in CDDP-injured kidneys of Gal-3-/- mice. Genetic deletion as well as pharmacological inhibition of Gal-3 in renal DCs remarkably reduced TLR-2-dependent activation of IDO1/KYN pathway in these cells diminishing their capacity to prevent transdifferentiation of Tregs in inflammatory Th1 and Th17 cells. Additionally, Tregs generated by Gal-3 deficient DCs were not able to suppress production of IFN-γ and IL-17 in activated neutrophils. TLR-2-primed DCs significantly enhanced capacity of Tregs for attenuation of CDDP-induced AKI and inflammation and expression of Gal-3 on TLR-2-primed DCs was crucially important for their capacity to enhance nephroprotective and immunosuppressive properties of Tregs. Adoptive transfer of TLR-2-primed WTDCs significantly expanded Tregs in the kidneys of CDDP-treated WT and Gal-3-/- recipients resulting in the suppression of IFN-γ and IL-17-driven inflammation and alleviation of AKI. Importantly, this phenomenon was not observed in CDDP-treated WT and Gal-3-/- recipients of TLR-2-primed Gal-3-/-DCs. Gal-3-dependent nephroprotective and immunosuppressive effects of renal DCs was due to the IDO1-induced expansion of renal Tregs since either inhibition of IDO1 activity in TLR-2-primed DCs or depletion of Tregs completely diminished DCs-mediated attenuation of CDDP-induced AKI. Conclusions: Gal-3 protects from CDDP-induced AKI by promoting TLR-2-dependent activation of IDO1/KYN pathway in renal DCs resulting in increased expansion of immunosuppressive Tregs in injured kidneys. Activation of Gal-3:TLR-2:IDO1 pathway in renal DCs should be further explored as new therapeutic approach for DC-based immunosuppression of inflammatory renal diseases.

Molecular and Cellular Mechanisms Involved in Mesenchymal Stem Cell-Based Therapy of Inflammatory Bowel Diseases.

Mesenchymal stem cells (MSCs) are promising resource for the therapy of inflammatory bowel diseases (IBDs) on the grounds of their differentiation capabilities and immuno-modulatory characteristics. Results of clinical studies indicate that local application of MSCs is a secure and beneficial approach for the treatment of perianal fistulas while systemic application of MSCs leads to the attenuation or aggravation of IBDs. Herein, we emphasized molecular mechanisms and approaches that should improve efficacy of MSC-based therapy of IBDs.

Mesenchymal Stem Cell-Dependent Modulation of Liver Diseases.

Acute liver failure and cirrhosis display sequential and overlapping severe pathogenic processes that include inflammation, hepatocyte necrosis, and fibrosis, carrying a high mortality rate. Mesenchymal stem cells (MSCs) are a heterogeneous subset of stromal stem cells with immunonodulatory characteristics. MSCs are considered to act through multiple mechanisms to coordinate a dynamic, integrated response to liver inflammation and fibrosis, which prevents the progressive distortion of hepatic architecture. Accordingly, MSCs as well as their products have been investigated as a novel therapeutic approach for the treatment of inflammatory and fibrotic liver diseases. In this review, we highlight the current findings on the MSC-based modulation of liver inflammation and fibrosis, and the possible use of MSCs in the therapy of immune-mediated liver pathology. We briefly describe the cellular and molecular mechanisms involved in MSC-dependent modulation of cytokine production, phenotype and function of liver infiltrated inflammatory cells and compare effects of engrafted MSCs versus MSC-generated conditioned medium (MSC-CM) in the therapy of acute liver injury. In order to elucidate therapeutic potential of MSCs and their products in modulation of chronic liver inflammation and fibrosis, we present the current findings regarding pathogenic role of immune cells in liver fibrosis and describe mechanisms involved in MSC-dependent modulation of chronic liver inflammation with the brief overview of on-going and already published clinical trials that used MSCs for the treatment of immune mediated chronic liver diseases. The accumulating evidence shows that MSCs had a significant beneficial effect in the treatment of immune-mediated liver diseases.

Angiogenic and lymphangiogenic profiles in histological variants of papillary thyroid carcinoma.

INTRODUCTION: Papillary thyroid carcinoma (PTC) is a well­differentiated tumor that occurs in several histological variants whose biological behaviors remain unclear. Angiogenesis and lymphangiogenesis are critical processes that enable tumor progression. OBJECTIVES: The aim of this study was to evaluate the angiogenic and lymphangiogenic phenotypes of PTC, considering the differences between histological variants. PATIENTS AND METHODS: Angiogenic and lymphangiogenic profiles were analyzed by determining microvascular density (MVD) and lymphatic vessel density (LVD) in 73 cases of PTC, using immunohistochemistry. To assess the biological markers involved in blood and lymph vessel formation, the expression of vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX­2), and p27kip1 (p27) was determined. RESULTS: MVD was significantly higher in patients with high­risk PTC and in those with local extrathyroidal and vascular invasion. Positive VEGF expression was strongly associated with high MVD and age­related tumor enlargement. The presence of lymph vessel invasion was associated with the expression of either VEGF or COX­2. The analysis of angiogenesis and lymphangiogenesis in different histological variants of PTC revealed elevated LVD rather than MVD in the follicular variant of PTC (FV­PTC).Lower MVD was observed in FV­PTC relative to the classic variant of PTC (CV­PTC). The frequency of VEGF­positive tumors was higher in CV­PTC than in FV­PTC. A significant association between COX­2 and p27 expression was observed in FV­PTC but not in CV­PTC. CONCLUSIONS: These results suggest that VEGF, COX­2, and p27 may be important biological markers that determine the angiogenic and lymphangiogenic potentials of PTC, particularly between the follicular and classic variants.

Low-dimensional compounds containing bioactive ligands. Part VI: Synthesis, structures, in vitro DNA binding, antimicrobial and anticancer properties of first row transition metal complexes with 5-chloro-quinolin-8-ol.

A series of new 3d metal complexes with 5-chloro-quinolin-8-ol (ClQ), [Mn(ClQ)2] (1), [Fe(ClQ)3] (2), [Co(ClQ)2(H2O)2] (3), [Ni(ClQ)2(H2O)2] (4), [Cu(ClQ)2] (5), [Zn(ClQ)2(H2O)2] (6), [Mn(ClQ)3]·DMF (7) and [Co(ClQ)3]·DMF·(EtOH)0.35 (8) (DMF=N,N-dimethylformamide), has been synthesized and characterized by elemental analysis, IR spectroscopy and TG-DTA thermal analysis. X-ray structure analysis of 7 and 8 revealed that these molecular complexes contain three chelate ClQ molecules coordinated to the central atoms in a deformed octahedral geometry and free space between the complex units is filled by solvated DMF and ethanol molecules. Antimicrobial activity of 1-6 was tested by determining the minimum inhibitory concentration and minimum microbicidal concentration against 12 strains of bacteria and 5 strains of fungi. The intensity of antimicrobial action varies depending on the group of microorganism and can be sorted: 1>ClQ>6>3/4>2>5. Complexes 1-6 exhibit high cytotoxic activity against MDA-MB, HCT-116 and A549 cancer cell lines. Among them, complex 2 is significantly more cytotoxic against MDA-MB cells than cisplatin at all tested concentrations and is not cytotoxic against control mesenchymal stem cells indicating that this complex seems to be a good candidate for future pharmacological evaluation. Interaction of 1-6 with DNA was investigated using UV-VIS spectroscopy, fluorescence spectroscopy and agarose gel electrophoresis. The binding studies indicate that 1-6 can interact with CT-DNA through intercalation; complex 2 has the highest binding affinity. Moreover, complexes 1-6 inhibit the catalytic activity of topoisomerase I.