A Narrative Review on Non-Cirrohotic Portal Hypertension: Not All Portal Hypertensions Mean Cirrhosis

Non-cirrhotic portal hypertension (NCPH), also known as idiopathic non-cirrhotic portal hypertension (INCPH) and porto-sinusoidal vascular disorder (PSVD), is a rare disease characterized by intrahepatic portal hypertension (IPH) in the absence of cirrhosis. The precise etiopathogenesis of IPH is an area of ongoing research. NCPH diagnosis is challenging, as there are no specific tests available to confirm the disease, and a high-quality liver biopsy, detailed clinical information, and an expert pathologist are necessary for diagnosis. Currently, the treatment of NCPH relies on the prevention of complications related to portal hypertension, following current guidelines of cirrhotic portal hypertension. No treatment has been studied that aimed to modify the natural history of the disease; however, transjugular intrahepatic porto-systemic shunt (TIPS) placement, shunt and liver transplantation are considerable symptomatic options. In this review, we discuss the heterogeneity of NCPH as well as its etiopathogenesis, clinical presentation and management issues. Starting from the assumption that portal hypertension does not always mean cirrhosis, cooperative studies are probably needed to clarify the issues of etiology and the possible genetic background of this rare disease. This knowledge might lead to better treatment and perhaps better prevention.

PDAC, the Influencer Cancer: Cross-Talk with Tumor Microenvironment and Connected Potential Therapy Strategies

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of death by cancer in the world. What makes this pathological condition particularly lethal is a combination of clinical and molecular heterogeneity, lack of early diagnostic indexes, and underwhelming results from current therapeutic protocols. A major cause of PDAC chemoresistance seems to lie in the ability of cancer cells to spread out and fill the pancreatic parenchyma, exchanging nutrients, substrates, and even genetic material with cells from the surrounding tumor microenvironment (TME). Several components can be found in the TME ultrastructure, including collagen fibers, cancer-associated fibroblasts, macrophages, neutrophils, mast cells, and lymphocytes. Cross-talk between PDAC and TME cells results in the latter being converted into cancer-favoring phenotypes; this behavior could be compared to an influencer guiding followers into supporting his activity. Moreover, TME could be a potential target for some of the newest therapeutic strategies; these include the use of pegvorhyaluronidase-α and CAR-T lymphocytes against HER2, FAP, CEA, MLSN, PSCA, and CD133. Other experimental therapy options are being currently studied, aiming to interfere with the KRAS pathway, DNA-repairing proteins, and apoptosis resistance in PDAC cells. Hopefully these new approaches will grant better clinical outcomes in future patients.

Open Questions in Cold Atmospheric Plasma Treatment in Head and Neck Cancer: A Systematic Review

Over the past decade, we witnessed a promising application of cold atmospheric plasma (CAP) in cancer therapy. The aim of this systematic review was to provide an exhaustive state of the art of CAP employed for the treatment of head and neck cancer (HNC), a tumor whose late diagnosis, local recurrence, distant metastases, and treatment failure are the main causes of patients’ death. Specifically, the characteristics and settings of the CAP devices and the in vitro and in vivo treatment protocols were summarized to meet the urgent need for standardization. Its molecular mechanisms of action, as well as the successes and pitfalls of current CAP applications in HNC, were discussed. Finally, the interesting emerging preclinical hypotheses that warrant further clinical investigation have risen. A total of 24 studies were included. Most studies used a plasma jet device (54.2%). Argon resulted as the mostly employed working gas (33.32%). Direct and indirect plasma application was reported in 87.5% and 20.8% of studies, respectively. In vitro investigations were 79.17%, most of them concerned with direct treatment (78.94%). Only eight (33.32%) in vivo studies were found; three were conducted in mice, and five on human beings. CAP showed pro-apoptotic effects more efficiently in tumor cells than in normal cells by altering redox balance in a way that oxidative distress leads to cell death. In preclinical studies, it exhibited efficacy and tolerability. Results from this systematic review pointed out the current limitations of translational application of CAP in the urge of standardization of the current protocols while highlighting promising effects as supporting treatment in HNC.

Effects of H2O2 Treatment Combined With PI3K Inhibitor and MEK Inhibitor in AGS Cells: Oxidative Stress Outcomes in a Model of Gastric Cancer

Gastric cancer is worldwide the fifth and third cancer for incidence and mortality, respectively. Stomach wall is daily exposed to oxidative stress and BER system has a key role in the defense from oxidation-induced DNA damage, whilst ErbB receptors have important roles in the pathogenesis of cancer. We used AGS cells as an aggressive gastric carcinoma cell model, treated with H₂O₂ alone or combined with ErbB signaling pathway inhibitors, to evaluate the effects of oxidative stress in gastric cancer, focusing on the modulation of ErbB signaling pathways and their eventual cross-talk with BER system. We showed that treatment with H₂O₂ combined with PI3K/AKT and MEK inhibitors influenced cell morphology and resulted in a reduction of cancer cell viability. Migration ability was reduced after H₂O₂ treatment alone or combined with MEK inhibitor and after PI3K/AKT inhibitor alone. Western blotting analysis showed that oxidative stress stimulated EGFR pathway favoring the MAPKs activation at the expense of PI3K/AKT pathway. Gene expression analysis by RT-qPCR showed ErbB2 and OGG1 increase under oxidative stress conditions. Therefore, we suggest that in AGS cells a pro-oxidant treatment can reduce gastric cancer cell growth and migration via a different modulation of PI3K and MAPKs pathways. Moreover, the observed ErbB2 and OGG1 induction is a cellular response to protect the cells from H₂O₂-induced cell death. In conclusion, to tailor specific combinations of therapies and to decide which strategy to use, administration of a chemotherapy that increases intracellular ROS to toxic levels, might not only be dependent on the tumor type, but also on the molecular targeting therapy used.

Emerging Role of Oxidative Stress on EGFR and OGG1-BER Cross-Regulation: Implications in Thyroid Physiopathology

Thyroid diseases have a complex and multifactorial aetiology. Despite the numerous studies on the signals referable to the malignant transition, the molecular mechanisms concerning the role of oxidative stress remain elusive. Based on its strong oxidative power, H2O2 could be responsible for the high level of oxidative DNA damage observed in cancerous thyroid tissue and hyperactivation of mitogen-activated protein kinase (MAPK) and PI3K/Akt, which mediate ErbB signaling. Increased levels of 8-oxoG DNA adducts have been detected in the early stages of thyroid cancer. These DNA lesions are efficiently recognized and removed by the base excision repair (BER) pathway initiated by 8-oxoG glycosylase1 (OGG1). This study investigated the relationships between the EGFR and OGG1-BER pathways and their mutual regulation following oxidative stress stimulus by H2O2 in human thyrocytes. We clarified the modulation of ErbB receptors and their downstream pathways (PI3K/Akt and MAPK/ERK) under oxidative stress (from H2O2) at the level of gene and protein expression, according to the mechanism defined in a human non-pathological cell system, Nthy-ori 3-1. Later, on the basis of the results obtained by gene expression cluster analysis in normal cells, we assessed the dysregulation of the relationships in a model of papillary thyroid cancer with RET/PTC rearrangement (TPC-1). Our observations demonstrated that a H2O2 stress may induce a physiological cross-regulation between ErbB and OGG1-BER pathways in normal thyroid cells (while this is dysregulated in the TPC-1 cells). Gene expression data also delineated that MUTYH gene could play a physiological role in crosstalk between ErbB and BER pathways and this function is instead lost in cancer cells. Overall, our data on OGG1 protein expression suggest that it was physiologically regulated in response to oxidative modulation of ErbB, and that these might be dysregulated in the signaling pathway involving AKT in the progression of thyroid malignancies with RET/PTC rearrangements.

Synthesis and Evaluation of Thymol-Based Synthetic Derivatives as Dual-Action Inhibitors against Different Strains of H. pylori and AGS Cell Line

Following a similar approach on carvacrol-based derivatives, we investigated the synthesis and the microbiological screening against eight strains of H. pylori, and the cytotoxic activity against human gastric adenocarcinoma (AGS) cells of a new series of ether compounds based on the structure of thymol. Structural analysis comprehended elemental analysis and ¹H/¹³C/¹⁹F NMR spectra. The analysis of structure–activity relationships within this molecular library of 38 structurally-related compounds reported that some chemical modifications of the OH group of thymol led to broad-spectrum growth inhibition on all isolates. Preferred substitutions were benzyl groups compared to alkyl chains, and the specific presence of functional groups at para position of the benzyl moiety such as 4-CN and 4-Ph endowed the most anti-H. pylori activity toward all the strains with minimum inhibitory concentration (MIC) values up to 4 µg/mL. Poly-substitution on the benzyl ring was not essential. Moreover, several compounds characterized by the lowest minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) values against H. pylori were also tested in order to verify a cytotoxic effect against AGS cells with respect to 5-fluorouracil and carvacrol. Three derivatives can be considered as new lead compounds alternative to current therapy to manage H. pylori infection, preventing the occurrence of severe gastric diseases. The present work confirms the possibility to use natural compounds as templates for the medicinal semi-synthesis.

Eradication of Helicobacter pylori and Gastric Cancer: A Controversial Relationship

Worldwide, gastric cancer (GC) represents the fifth cancer for incidence, and the third as cause of death in developed countries. Indeed, it resulted in more than 780,000 deaths in 2018. Helicobacter pylori appears to be responsible for the majority of these cancers. On the basis of recent studies, and either alone or combined with additional etiological factors, H. pylori is considered a “type I carcinogen.” Over recent decades, new insights have been obtained into the strategies that have been adopted by H. pylori to survive the acidic conditions of the gastric environment, and to result in persistent infection, and dysregulation of host functions. The multistep processes involved in the development of GC are initiated by transition of the mucosa into chronic non-atrophic gastritis, which is primarily triggered by infection with H. pylori. This gastritis then progresses into atrophic gastritis and intestinal metaplasia, and then to dysplasia, and following Correa’s cascade, to adenocarcinoma. The use of antibiotics for eradication of H. pylori can reduce the incidence of precancerous lesions only in the early stages of gastric carcinogenesis. Here, we first survey the etiology and risk factors of GC, and then we analyze the mechanisms underlying tumorigenesis induced by H. pylori, focusing attention on virulence factor CagA, inflammation, oxidative stress, and ErbB2 receptor tyrosine kinase. Moreover, we investigate the relationships between H. pylori eradication therapy and other diseases, considering not only cardia (upper stomach) cancers and Barrett’s esophagus, but also asthma and allergies, through discussion of the “hygiene hypothesis. ” This hypothesis suggests that improved hygiene and antibiotic use in early life reduces microbial exposure, such that the immune response does not become primed, and individuals are not protected against atopic disorders, asthma, and autoimmune diseases. Finally, we overview recent advances to uncover the complex interplay between H. pylori and the gut microbiota during gastric carcinogenesis, as characterized by reduced bacterial diversity and increased microbial dysbiosis. Indeed, it is of particular importance to identify the bacterial taxa of the stomach that might predict the outcome of gastric disease through the stages of Correa’s cascade, to improve prevention and therapy of gastric carcinoma.

Synthesis and Biological Evaluation of Carvacrol-Based Derivatives as Dual Inhibitors of H. pylori Strains and AGS Cell Proliferation

This study reports on the synthesis, structural assessment, microbiological screening against several strains of H. pylori and antiproliferative activity against human gastric adenocarcinoma (AGS) cells of a large series of carvacrol-based compounds. Structural analyses consisted of elemental analysis, 1H/13C/19F NMR spectra and crystallographic studies. The structure-activity relationships evidenced that among ether derivatives the substitution with specific electron-withdrawing groups (CF3 and NO2) especially in the para position of the benzyl ring led to an improvement of the antimicrobial activity, whereas electron-donating groups on the benzyl ring and ethereal alkyl chains were not tolerated with respect to the parent compound (MIC/MBC = 64/64 µg/mL). Ester derivatives (coumarin-carvacrol hybrids) displayed a slight enhancement of the inhibitory activity up to MIC values of 8-16 µg/mL. The most interesting compounds exhibiting the lowest MIC/MBC activity against H. pylori (among others, compounds 16 and 39 endowed with MIC/MBC values ranging between 2/2 to 32/32 µg/mL against all the evaluated strains) were also assayed for their ability to reduce AGS cell growth with respect to 5-Fluorouracil. Some derivatives can be regarded as new lead compounds able to reduce H. pylori growth and to counteract the proliferation of AGS cells, both contributing to the occurrence of gastric cancer.

Antimicrobial and Antibiofilm Activities of New Synthesized Silver Ultra-NanoClusters (SUNCs) Against Helicobacter pylori

Helicobacter pylori colonizes approximately 50% of the world’s population, and it is the cause of chronic gastritis, peptic ulcer disease, and gastric cancer. The increase of antibiotic resistance is one of the biggest challenges of our century due to its constant increase. In order to identify an alternative or adjuvant strategy to the standard antibiotic therapy, the in vitro activity of newly synthesized Silver Ultra-NanoClusters (SUNCs), characterized by an average size inferior to 5 nm, against clinical strains of H. pylori, with different antibiotic susceptibilities, was evaluated in this study. MICs and MBCs were determined by the broth microdilution method, whereas the effect of drug combinations was determined by the checkerboard assay. The Minimum Biofilm Eradication Concentration (MBEC) was measured using AlamarBlue (AB) assay and colony-forming unit (CFU) counts. The cytotoxicity was evaluated by performing the MTT assay on the AGS cell line. The inhibitory activity was expressed in terms of bacteriostatic and bactericidal potential, with MIC₅₀, MIC₉₀, and MBC₅₀ of 0.33 mg/L against planktonic H. pylori strains. Using the fractional inhibitory concentration index (FICI), SUNCs showed potential synergism with metronidazole and clarithromycin. The biofilm eradication was obtained after treatment with 2×, 3×, and 4× MIC values. Moreover, SUNCs showed low toxicity on human cells and were effective in eradicating a mature biofilm produced by H. pylori. The data presented in this study demonstrate that SUNCs could represent a novel strategy for the treatment of H. pylori infections either alone or in combination with metronidazole.

Doxorubicin‑induced oxidative and nitrosative stress: Mitochondrial connexin 43 is at the crossroads

Oxidative stress is widely accepted as a key factor of doxorubicin (Doxo)-induced cardiotoxicity. There is evidence to indicate that nitrosative stress is involved in this process, and that Doxo interacts by amplifying cell damage. Mitochondrial connexin 43 (mitoCx43) can confer cardioprotective effects through the reduction of mitochondrial reactive oxygen species production during Doxo-induced cardiotoxicity. The present study aimed to evaluate the involvement of mitoCx43 in Doxo-induced nitrosative stress. Rat H9c2 cardiomyoblasts were treated with Doxo in the absence or presence of radicicol, an inhibitor of Hsp90, the molecular chaperone involved in Cx43 translocation to the mitochondria that underlies its role in cardioprotection. FACS analysis and RT-qPCR revealed that Doxo increased superoxide dismutase, and catalase gene and protein expression. As shown by hypodiploid nuclei and confirmed by western blot analysis, Doxo increased caspase 9 expression and reduced procaspase 3 levels, which induced cell death. Moreover, a significant increase in the activation of the NF-κB signaling pathway was observed. It is well known that the increased expression of inducible nitric oxide synthase results in nitric oxide overproduction, which then rapidly reacts with hydrogen peroxide or superoxide generated by the mitochondria, to form highly reactive and harmful peroxynitrite, which ultimately induces nitrotyrosine formation. Herein, these interactions were confirmed and increased effects were observed in the presence of radicicol. On the whole, the data of the present study indicate that an interplay between oxidative and nitrosative stress is involved in Doxo-induced cardiotoxicity, and that both aspects are responsible for the induction of apoptosis. Furthermore, it is demonstrated that the mechanisms that further increase mitochondrial super-oxide generation (e.g., the inhibition of Cx43 translocation into the mitochondria) significantly accelerate the occurrence of cell death.

Identification and characterization of the α-CA in the outer membrane vesicles produced by Helicobacter pylori

The genome of Helicobacter pylori encodes for carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the α- and β-CA classes, which together with urease, have a pivotal role in the acid acclimation of the microorganism within the human stomach. Recently, in the exoproteome of H. pylori, a CA with no indication of the corresponding class was identified. Here, using the protonography and the mass spectrometry, a CA belonging to the α-class was detected in the outer membrane vesicles (OMVs) generated by planktonic and biofilm phenotypes of four H. pylori strains. The amount of this metalloenzyme was higher in the planktonic OMVs (pOMVs) than in the biofilm OMVs (bOMVs). Furthermore, the content of α-CA increases over time in the pOMVs. The identification of the α-CA in pOMVs and bOMVs might shed new light on the role of this enzyme in the colonization, survival, persistence, and pathogenesis of H. pylori.

BK channels blockage inhibits hypoxia-induced migration and chemoresistance to cisplatin in human glioblastoma cells

Glioblastoma (GBM) cells express large-conductance, calcium-activated potassium (BK) channels, whose activity is important for several critical aspects of the tumor, such as migration/invasion and cell death. GBMs are also characterized by a heavy hypoxic microenvironment that exacerbates tumor aggressiveness. Since hypoxia modulates the activity of BK channels in many tissues, we hypothesized that a hypoxia-induced modulation of these channels may contribute to the hypoxia-induced GBM aggressiveness. In U87-MG cells, hypoxia induced a functional upregulation of BK channel activity, without interfering with their plasma membrane expression. Wound healing and transwell migration assays showed that hypoxia increased the migratory ability of U87-MG cells, an effect that could be prevented by BK channel inhibition. Toxicological experiments showed that hypoxia was able to induce chemoresistance to cisplatin in U87-MG cells and that the inhibition of BK channels prevented the hypoxia-induced chemoresistance. Clonogenic assays showed that BK channels are also used to increase the clonogenic ability of U87-MG GBM cells in presence, but not in absence, of cisplatin. BK channels were also found to be essential for the hypoxia-induced de-differentiation of GBM cells. Finally, using immunohistochemical analysis, we highlighted the presence of BK channels in hypoxic areas of human GBM tissues, suggesting that our findings may have physiopathological relevance in vivo. In conclusion, our data show that BK channels promote several aspects of the aggressive potential of GBM cells induced by hypoxia, such as migration and chemoresistance to cisplatin, suggesting it as a potential therapeutic target in the treatment of GBM.

Detection and Physicochemical Characterization of Membrane Vesicles (MVs) of Lactobacillus reuteri DSM 17938

Membrane vesicles (MVs) are bilayer structures which bleb from bacteria, and are important in trafficking biomolecules to other bacteria or host cells. There are few data about MVs produced by the Gram-positive commensal-derived probiotic Lactobacillus reuteri; however, MVs from this species may have potential therapeutic benefit. The aim of this study was to detect and characterize MVs produced from biofilm (bMVs), and planktonic (pMVs) phenotypes of L. reuteri DSM 17938. MVs were analyzed for structure and physicochemical characterization by Scanning Electron Microscope (SEM) and Dynamic Light Scattering (DLS). Their composition was interrogated using various digestive enzyme treatments and subsequent Transmission Electron Microscopy (TEM) analysis. eDNA (extracellular DNA) was detected and quantified using PicoGreen. We found that planktonic and biofilm of L. reuteri cultures generated MVs with a broad size distribution. Our data also showed that eDNA was associated with pMVs and bMVs (e_MVsDNA). DNase I treatment demonstrated no modifications of MVs, suggesting that an eDNA-MVs complex protected the e_MVsDNA. Proteinase K and Phospholipase C treatments modified the structure of MVs, showing that lipids and proteins are important structural components of L. reuteri MVs. The biological composition and the physicochemical characterization of MVs generated by the probiotic L. reuteri may represent a starting point for future applications in the development of vesicles-based therapeutic systems.

Effects of PPARα inhibition in head and neck paraganglioma cells

Head and neck paragangliomas (HNPGLs) are rare tumors that may cause important morbidity, because of their tendency to infiltrate the skull base. At present, surgery is the only therapeutic option, but radical removal may be difficult or impossible. Thus, effective targets and molecules for HNPGL treatment need to be identified. However, the lack of cellular models for this rare tumor hampers this task. PPARα receptor activation was reported in several tumors and this receptor appears to be a promising therapeutic target in different malignancies. Considering that the role of PPARα in HNPGLs was never studied before, we analyzed the potential of modulating PPARα in a unique model of HNPGL cells. We observed an intense immunoreactivity for PPARα in HNPGL tumors, suggesting that this receptor has an important role in HNPGL. A pronounced nuclear expression of PPARα was also confirmed in HNPGL-derived cells. The specific PPARα agonist WY14643 had no effect on HNPGL cell viability, whereas the specific PPARα antagonist GW6471 reduced HNPGL cell viability and growth by inducing cell cycle arrest and caspase-dependent apoptosis. GW6471 treatment was associated with a marked decrease of CDK4, cyclin D3 and cyclin B1 protein expression, along with an increased expression of p21 in HNPGL cells. Moreover, GW6471 drastically impaired clonogenic activity of HNPGL cells, with a less marked effect on cell migration. Notably, the effects of GW6471 on HNPGL cells were associated with the inhibition of the PI3K/GSK3β/β-catenin signaling pathway. In conclusion, the PPARα antagonist GW6471 reduces HNPGL cell viability, interfering with cell cycle and inducing apoptosis. The mechanisms affecting HNPGL cell viability involve repression of the PI3K/GSK3β/β-catenin pathway. Therefore, PPARα could represent a novel therapeutic target for HNPGL.

Identification of the zinc finger 216 (ZNF216) in human carcinoma cells: a potential regulator of EGFR activity

Epidermal Growth Factor Receptor (EGFR), a member of the ErbB family of receptor tyrosine kinase (RTK) proteins, is aberrantly expressed or deregulated in tumors and plays pivotal roles in cancer onset and metastatic progression. ZNF216 gene has been identified as one of Immediate Early Genes (IEGs) induced by RTKs. Overexpression of ZNF216 protein sensitizes 293 cell line to TNF-α induced apoptosis. However, ZNF216 overexpression has been reported in medulloblastomas and metastatic nasopharyngeal carcinomas. Thus, the role of this protein is still not clearly understood. In this study, the inverse correlation between EGFR and ZNF216 expression was confirmed in various human cancer cell lines differently expressing EGFR. EGF treatment of NIH3T3 cells overexpressing both EGFR and ZNF216 (NIH3T3-EGFR/ZNF216), induced a long lasting activation of EGFR in the cytosolic fraction and an accumulation of phosphorylated EGFR (pEGFR) more in the nuclear than in the cytosolic fraction compared to NIH3T3-EGFR cells. Moreover, EGF was able to stimulate an increased expression of ZNF216 in the cytosolic compartment and its nuclear translocation in a time-dependent manner in NIH3T3-EGFR/ZNF216. A similar trend was observed in A431 cells endogenously expressing the EGFR and transfected with Znf216. The increased levels of pEGFR and ZNF216 in the nuclear fraction of NIH3T3-EGFR/ZNF216 cells were paralleled by increased levels of phospho-MAPK and phospho-Akt. Surprisingly, EGF treatment of NIH3T3-EGFR/ZNF216 cells induced a significant increase of apoptosis thus indicating that ZNF216 could sensitize cells to EGF-induced apoptosis and suggesting that it may be involved in the regulation and effects of EGFR signaling.

Genomic Organization and Cytokine-Mediated Inducibility of the Human Trim-8/Gerp Gene

Cytokine signaling is negatively regulated by a set of SH2 domain-containing proteins, the Suppressors of Cytokine Signaling (SOCS) acting as intracellular modulators. Experimental evidence indicates that SOCS gene expression is induced by cytokines and pro-inflammatory stimuli and is highly controlled both at transcription and translation level. Furthermore, SOCS proteins appear rapidly degraded inside the cells, mostly controlling their stability by interacting with specific molecules such as elongin B and C. It has been shown that SOCS-1/JAB, a member of the SOCS family, interacts with TRIM-8/Gerp, a new ring protein specifically binding SOCS-1 recombinant polypeptide in-vitro and in-vivo. Trim-8/Gerp, transcribes a 3.0-kb mRNA, spans 551 AA and is highly conserved during evolution. In addition, it can be induced by IFN-γ in epithelial and lymphoid cells and is expressed mostly ubiquitously in murine and human tissues. Here in this report we present the genomic organization of this new SOCS-1 interactor, and we add new tools for extending investigation of the complex mechanism that undergoes negatively regulation of cytokine signaling.

Helicobacter pylori ATCC 43629/NCTC 11639 Outer Membrane Vesicles (OMVs) from Biofilm and Planktonic Phase Associated with Extracellular DNA (eDNA)

Helicobacter pylori persistence is associated with its capacity to develop biofilms as a response to changing environmental conditions and stress. Extracellular DNA (eDNA) is a component of H. pylori biofilm matrix but the lack of DNase I activity supports the hypothesis that eDNA might be protected by other extracellular polymeric substances (EPS) and/or Outer Membrane Vesicles (OMVs), which bleb from the bacteria surface during growth. The aim of the present study was to both identify the eDNA presence on OMVs segregated from H. pylori ATCC 43629/NCTC 11639 biofilm (bOMVs) and its planktonic phase (pOMVs) and to characterize the physical-chemical properties of the OMVs. The presence of eDNA in bOMVs and pOMVs was initially carried out using DNase I-gold complex labeling and Transmission Electron Microscope analysis (TEM). bOMVs and pOMVs were further isolated and physical-chemical characterization carried out using dynamic light scattering (DLS) analysis. eDNA associated with OMVs was detected and quantified using a PicoGreen spectrophotometer assay, while its extraction was performed with a DNA Kit. TEM images showed that eDNA was mainly associated with the OMV membrane surfaces; while PicoGreen staining showed a four-fold increase of dsDNA in bOMVs compared with pOMVs. The eDNA extracted from OMVs was visualized using gel electrophoresis. DLS analysis indicated that both planktonic and biofilm H. pylori phenotypes generated vesicles, with a broad distribution of sizes on the nanometer scale. The DLS aggregation assay suggested that eDNA may play a role in the aggregation of OMVs, in the biofilm phenotype. Moreover, the eDNA associated with vesicle membrane may impede DNase I activity on H. pylori biofilms. These results suggest that OMVs derived from the H. pylori biofilm phenotype may play a structural role by preventing eDNA degradation by nucleases, providing a bridging function between eDNA strands on OMV surfaces and promoting aggregation.

The antitumor potential of Interleukin-27 in prostate cancer

Prostate cancer (PCa) is of increasing significance worldwide as a consequence of the population ageing. Fragile elderly patients may particularly benefit from noninvasive and well tolerable immunotherapeutic approaches. Preclinical studies have revealed that the immune-regulatory cytokine IL-27 may exert anti-tumor activities in a variety of tumor types without discernable toxicity. We, thus, investigated whether IL-27 may function as anti-tumor agent in human (h) PCa and analyzed the rationale for its clinical application.

In vitro, IL-27 treatment significantly inhibited proliferation and reduced the angiogenic potential of hPCa cells by down-regulating the pro-angiogenesis-related genes fms-related tyrosine kinase (FLT)1, prostaglandin G/H synthase 1/cyclooxygenase-1 (PTGS1/COX-1) and fibroblast growth factor receptor (FGFR)3. In addition, IL-27 up-regulated the anti-angiogenesis-related genes such as CXCL10 and TIMP metallopeptidase inhibitor 3 (TIMP3). In vivo, IL-27 reduced proliferation and vascularization in association with ischemic necrosis of tumors developed after PC3 or DU145 cell injection in athymic nude mice. In patients' prostate tissues, IL-27R was expressed by normal epithelia and low grade PCa and lost by high tumor grade and stages. Nevertheless, IL-27R was expressed by CD11c⁺, CD4⁺ and CD8⁺ leukocytes infiltrating the tumor and draining lymph nodes.

These data lead to the conclusion that i) IL-27's anti-PCa potential may be fully exploited in patients with well-differentiated, localized IL-27R positive PCa, since in this case it may act on both cancerous epithelia and the tumor microenvironment; ii) PCa patients bearing high grade and stage tumor that lack IL-27R may benefit, however, from IL-27's immune-stimulatory properties.

Nuclear fractal dimension in oral squamous cell carcinoma: a novel method for the evaluation of grading, staging, and survival

Fractal dimension (FD) in tissue specimens from patients with oral squamous cell carcinoma (OSCC) was evaluated. FD values in different stages of OSCC, and the correlations with clinicopathological variables and patient survival were investigated. Histological sections from OSCC and control non-neoplastic mucosa specimens were stained with hematoxylin-eosin for pathological analysis and with Feulgen for nuclear evaluation. FD in OSCC groups vs. controls revealed statistically significant differences (P < 0.001). In addition, a progressive increase of FD from stage I and II lesions and stage III and IV lesions was observed, with statistically significant differences (P = 0.003). Moreover, different degrees of tumor differentiation showed a significant difference in the average nuclear FD values (P = 0.001). A relationship between FD and patients' survival was also detected with lower FD values associated to longer survival time and higher FD values with shorter survival time (P = 0.034). These data showed that FD significantly increased during OSCC progression. Thus, FD could represent a novel prognostic tool for OSCC, as FD values significantly correlated with patient survival. Fractal geometry could give insights into tumor morphology and could become an useful tool for analyzing irregular tumor growth patterns.

PRDX1 and PRDX6 are repressed in papillary thyroid carcinomas via BRAF V600E-dependent and -independent mechanisms

Many clinical studies highlight the dichotomous role of PRDXs in human cancers, where they can exhibit strong tumor-suppressive or tumor-promoting functions. Recent evidence suggests that lower expression of PRDXs correlates with cancer progression in colorectal cancer (CRC) or in esophageal squamous carcinoma. In the thyroid, increased levels of PRDX1 has been described in follicular adenomas and carcinomas, as well as in thyroiditis, while reduced levels of PRDX6 has been found in follicular adenomas. We studied the expression of PRDX1 and PRDX6, in a series of thyroid tissue samples, covering different thyroid diseases, including 13 papillary thyroid carcinomas (PTCs). Our results show that PRDX1 and PRDX6 are significantly reduced in all PTCs compared to normal tissues, to non-neoplastic tissue (MNG) or follicular neoplasms. This reduction is strongly evident in PTCs harboring BRAF V600E (31% of our cases). Using TPC-1 and BCPAP and FRTL-5 cell lines, we demonstrate for the first time that the presence of BRAF V600E is responsible of the hypoexpression of PRDX1 and PRDX6 both at mRNA and protein levels. Finally, independently of BRAF status, we observe an interesting correlation between the tumor size, the presence of lymph node metastasis and the lowest PRDX1 and PRDX6 levels. Therefore, these data indicate that PRDX1 and PRDX6 expression not only may play a key role in papillary thyroid carcinogenesis via a BRAF V600E-dependent mechanism, but their determination could be considered as potential tumor marker for indicating tumor progression in PTCs, independently of BRAF status.

EGF and TGF-β1 Effects on Thyroid Function

Normal epithelial thyroid cells in culture are inhibited by TGF-β1. Instead, transformed thyroid cell lines are frequently resistant to its growth inhibitory effect. Loss of TGF-β responsiveness could be due to a reduced expression of TGF-β receptors, as shown in transformed rat thyroid cell lines and in human thyroid tumors, or to alterations of other genes controlling TGF-β signal transduction pathway. However, in thyroid neoplasia, a complex pattern of alterations occurring during transformation and progression has been identified. Functionally, TGF-β1 acts as a tumor suppressor in the early stage of transformation or as a tumor promoter in advanced cancer. This peculiar pleiotropic behaviour of TGF-β may result from cross-talk with signalling pathways mediated by other growth factors, among which EGF-like ligands play an important role. This paper reports evidences on TGF-β1 and EGF systems in thyroid tumors and on the cross-talk between these growth factors in thyroid cancer.

Loss of expression of TGF-beta1, TbetaRI, and TbetaRII correlates with differentiation in human oral squamous cell carcinomas

Despite advances in biological and molecular characteristics, the prognosis of oral squamous cell carcinomas is still very unfavourable and is based on the classical clinicopathological parameters. However, tumors with similar clinicopathological characteristics may differ dramatically in their clinical outcome. Thus, the identification of novel prognostic factors is necessary to improve prognostic and therapeutic approaches. Transforming growth factor-beta1 (TGF-beta1) is a potent growth inhibitor of epithelial cell proliferation, thus, inactivation of TGF-beta1 signalling may play a role in cancer. The expression levels of TGF-beta1 and its type I and type II receptors (TbetaRI and TbetaRII) were assessed by immunohistochemical and Western blot analyses in 22 oral squamous cell carcinoma lesions, in their normal adjacent mucosa and in the squamous carcinoma cell lines FaDu and CAL27. Immunohistochemistry on 22 oral carcinomas and case-matched normal oral mucosae demonstrated that TGF-beta1, TbetaRI, and TbetaRII were intensively and homogeneously expressed in all normal epithelia. In contrast, TGF-beta1 and its receptors were significantly reduced in poorly (G3) differentiated tumors as compared to moderately (G2) and well differentiated (G1) lesions (p=2.8 x 10(-3), p=1.3 x 10(-3), p=2.8 x 10(-3) and p=1.3 x 10(-3), respectively). The progressive reduction of the expression levels was confirmed by Western blotting. The oral squamous carcinoma cell lines Cal27 and FaDu demonstrated a reduced and a lack of TbetaRI expression, respectively. A significant decrease of TbetaRII expression, as compared to Cal27 cells, was shown in FaDu cells. Thus, the decreased expression of TbetaRII combined with the absence of TbetaRI could account for the resistance of FaDu cells to the growth-inhibiting effect of TGF-beta1. TGF-beta1 and TGF-beta1 receptor expression significantly decreased as tumors became less differentiated and thus more aggressive, suggesting a functional role of these molecules in oral tumor progression.

Selective Insulin Resistance Affecting Nitric Oxide Release But Not Plasminogen Activator Inhibitor-1 Synthesis in Fibroblasts From Insulin-Resistant Individuals

OBJECTIVE

Insulin activates several processes potentially dangerous for the arterial wall and hyperinsulinemia might be atherogenic. However, other insulin effects are protective for the vessel wall and thus anti-atherogenic. Aim of this study was to investigate whether insulin effects on potentially pro-atherogenic and anti-atherogenic processes were differently affected in cells from insulin-resistant individuals.

METHODS AND RESULTS

We determined insulin effect on nitric oxide (NO) production and plasminogen activator inhibitor (PAI)-1 synthesis in 12 fibroblast strains obtained from skin biopsy samples of 6 insulin-sensitive (IS) (clamp M >7 mg/kg body weight per minute) and 6 insulin-resistant (IR) (clamp M <5 mg/kg body weight per minute) healthy volunteers. Insulin effects on NO release and Akt phosphorylation were significantly impaired in fibroblasts from IR as compared with IS individuals. Conversely, there was not any difference between IR and IS strains in insulin ability to increase PAI-1 antigen levels and, after 24-hour insulin incubation, PAI-1 mRNA increase in IR strains was only slightly less than in IS strains. Insulin ability to induce MAPK activation was also comparable in IR and IS cells.

CONCLUSIONS

We conclude that in cells from IR individuals, insulin action on anti-atherogenic processes, such as NO release, is impaired, whereas the hormone ability to stimulate atherogenic processes, such as PAI-1 release, is preserved.

Uncertainty of inductively coupled plasma mass spectrometry based measurements: an application to the analysis of urinary barium, cesium, antimony and tungsten

The wide use of barium (Ba), cesium (Cs), antimony (Sb) and tungsten (W) in many industrial and agricultural fields causes the increased release of these metals into the environment, laying the basis for health risk. To assess the exposure for the general population, the development of adequate and reliable analytical techniques becomes compulsory. This study refers to the quantification of urinary Ba, Cs, Sb and W levels by both quadrupole (Q) and sector field (SF) inductively coupled plasma mass spectrometry (ICP-MS). The two procedures were compared for their performances and their measurement uncertainties. The limits of detection were (Q and SF) 23.0 and 5.21 ng L(-1) for Ba; 21.1 and 7.52 ng L(-1) for Cs; 1.09 and 0.43 ng L(-1) for Sb; and 0.36 and 0.49 ng L(-1) for W. The trueness was better than 93.3% and the precision less than 12% for both techniques. Relative expanded uncertainties of the analytical procedures, at the median levels found in the general population, were below 5% for all the elements with both ICP-MS techniques. The uncertainties related to the calibration and repeatability were the parameters most influencing the final analytical performance. The urinary median values observed in healthy subjects from central Italy were 1146, 4301, 60.8 and 48.5 ng L(-1) for Ba, Cs, Sb and W, respectively.

Increased Expression of Transforming Growth Factor-β1 as a Stabilizing Factor in Human Atherosclerotic Plaques

BACKGROUND AND PURPOSE

Transforming growth factor-beta (TGF-beta) is a growth factor/cytokine involved in vascular remodeling and atherogenesis. Recent studies in apolipoprotein E-deficient mice have demonstrated a pivotal role of TGF-beta in the maintenance of the balance between inflammation and fibrosis in atherosclerotic plaques. Furthermore, inhibition of TGF-beta signaling has been shown to accelerate plaque formation and its progression toward an unstable phenotype in mice. However, if this mechanism is operative also in humans is still unknown. The aim of this study was to characterize the expression of TGF-beta1 in human carotid plaque and to correlate it with the extent of inflammatory infiltration and collagen content with the clinical signs of plaque instability.

METHODS

Plaques were obtained from patients undergoing carotid endoarterectomy and divided into symptomatic and asymptomatic according to clinical evidence of recent transient ischemic attack or stroke. Plaques were analyzed for TGF-beta1 expression by Immunocytochemistry, Western, and Northern blotting analysis. Immunocytochemistry was used to identify CD68+ macrophages, CD3 T lymphocytes, HLA-DR+ cells, and alpha-smooth muscle cells. Procollagen and interstitial collagen content were analyzed by immunohistochemistry and Sirius Red staining, respectively.

RESULTS

Plaque TGF-beta1 mRNA was increased up to 3-fold in asymptomatic as compared with symptomatic plaques. Plaques from asymptomatic group had fewer (P<0.0001) macrophages and T lymphocytes compared with symptomatic plaques. TGF-beta1 gene was transcriptionally active as demonstrated by increased (P<0.0001) TGF-beta1 protein expression in asymptomatic plaques. Immunohistochemistry showed that TGF-beta was mainly expressed in plaque shoulder and was associated with a comparable increase (P<0.0001) in plaque procollagen and collagen content.

CONCLUSIONS

In conclusion, this study demonstrates the higher expression of TGF-beta1 in human asymptomatic lesions and provides evidence that TGF-beta1 may play an important role in the process of plaque stabilization.

Pravastatin up-regulates transforming growth factor-β1 in THP-1 human macrophages: effect on scavenger receptor class A expression

Statins have been shown to interact with several monocyte/macrophage functions. We tested the effect of pravastatin on transforming growth factor-beta1 (TGF-beta1) production and its possible involvement in scavenger receptors class A (SRA) expression in human THP-1 cells. TGF-beta1s biological activity in THP-1 cell conditioned medium, evaluated by luciferase activity of transfected cell with a TGF-beta responsive promoter, was increased in a dose-dependent manner after incubation with pravastatin (1-20 microM). Pravastatin (1-20 microM) induced a dose-dependent increase in TGF-beta1 mRNA expression and protein production in THP-1 cells. PMA-induced SRA gene and protein expression was suppressed by pravastatin with a mean 3-fold decrease at 10 microM. This last effect was reversed by a mouse monoclonal anti-TGF-beta1 neutralizing antibody. PD98059, a specific inhibitor of MAP kinase cascade, completely reversed pravastatin-induced SRA down-regulation. p44 and p42 isoforms showed a dose-dependent phosphorylation after treatment with pravastatin (1-20 microM) which was inhibited by a mouse monoclonal anti-TGF-beta1 antibody. Our results demonstrate that pravastatin significantly up-regulates TGF-beta1 expression which may be in involved in down-regulation of SRA expression in THP-1 cell cultures. A new pathway for pravastatin effects in atherogenesis can be suggested.

Protease inhibitors: Synthesis of L-alanine hydroxamate sulfonylated derivatives as inhibitors of clostridium histolyticum collagenase

L-alanine hydroxamate derivatives were obtained by reaction of alkyl/arylsulfonyl halides with L-alanine, followed by treatment with benzyl chloride, and conversion of the COOH moiety to the CONHOH group with hydroxylamine in the presence of carbodiimides. Other derivatives were obtained by reaction of N-benzyl-alanine with aryl isocyanates, arylsulfonyl isocyanates or benzoyl isothiocyanate, followed by a similar conversion of the COOH to the CONHOH moiety. The obtained compounds were assayed as inhibitors of Clostridium histolyticum collagenase, ChC (EC 3.4.24.3), a zinc enzyme which degrades triple helical collagen. The hydroxamate derivatives were generally 100-500 times more active than the corresponding carboxylates. In the series of synthesized derivatives, substitution patterns leading to the most potent ChC inhibitors were those involving perfluoroalkylsulfonyl- and substituted-arylsulfonyl moieties, such as pentafluorophenylsulfonyl, 3- and 4-protected-aminophenylsulfonyl-, 3- and 4-carboxy-phenylsulfonyl-, 3-trifluoromethyl-phenylsulfonyl-, or 1- and 2-naphthylsulfonyl among others. Similarly to the matrix metalloproteinase (MMP) hydroxamate inhibitors, ChC inhibitors of the type reported here must incorporate hydrophobic moieties at the P(2') and P(3') sites, in order to achieve tight binding to the enzyme.

Carbonic anhydrase inhibitors. metal complexes of 5-(2-chlorophenyl)-1,3,4-thiadiazole-2-sulfonamide with topical intraocular pressure lowering properties: the influence of metal ions upon the pharmacological activity

Metal complexes of a sulfonamide possessing strong carbonic anhydrase (CA) inhibitory properties, 5-(2-chlorophenyl)-1,3,4-thiadiazole-2-sulfonamide (chlorazolamide) have been obtained from the sodium salt of the sulfonamide and the following metal ions: Mg(II), Zn(II), Mn(II), Cu(II), Co(II), Ni(II), Be(II), Cd(II), Pb(II), Al(III), Fe(III) and La(III). The original sulfonamide and its complexes were assayed for the in vitro inhibition of three CA isozymes, CA I, II, and IV, some of which play a critical role in ocular fluid secretion. All these compounds (the sulfonamide and its metal complexes) behaved as powerful inhibitors against the three investigated isozymes. The parent sulfonamide possessed an extremely weak topical pressure lowering effect when administered as a 1-2% suspension into the rabbit eye, but some of its metal complexes, such as the Mg(II), Zn(II), Mn(II) and Cu(II) derivatives, lower intraocular pressure (IOP) in experimental animals very well. Ex vivo data showed a 99.5-99.9% CA II inhibition in ocular fluids and tissues of rabbits treated with these agents, proving that the observed IOP lowering is due to CA inhibition. The influence of the different metal ions upon the efficiency of the obtained complexes as pressure lowering drugs are discussed, leading to the possibility of designing more selective/potent pharmacological agents from this class.

TGF-beta 1 modulation of IGF-I signaling pathway in rat thyroid epithelial cells

Transforming growth factor beta 1 (TGF-beta 1) and insulin-like growth factor I (IGF-I) have contrasting effects on cell cycle regulation in thyroid cells and TGF-beta 1 induces a dramatic decrease in IGF-I-induced cell proliferation. The aim of the present study was to investigate the molecular mechanism of cross-talk between TGF-beta 1 and IGF-I in FRTL-5 cells. TGF-beta 1 affected IGF-I-stimulated insulin receptor substrate 1 (IRS-1) tyrosine phosphorylation and its association with Grb2 protein. Moreover, TGF-beta 1 decreased the IGF-I-induced tyrosine phosphorylation of the adaptor protein CrkII and its association with the IGF-I receptor. These results were accompanied by TGF-beta 1 inhibition of IGF-I-stimulated mitogen-activated protein kinase phosphorylation and activation. Conversely, TGF-beta 1 did not alter IGF-I-stimulated IRS-1-associated phosphatidylinositol 3-kinase activity, IGF-I-induced tyrosine phosphorylation of Shc, and its binding to Grb2. Taken together, these findings provide a molecular basis for the growth-inhibitory action of TGF-beta 1 on the IGF-I-induced mitogenic effect.

Carbonic anhydrase inhibitors: synthesis of sulfonamides incorporating dtpa tails and of their zinc complexes with powerful topical antiglaucoma properties

Reaction of diethylenetriamino pentaacetic acid (dtpa) dianhydride with aromatic/heterocyclic sulfonamides possessing a free amino/imino/hydrazino/hydroxy group afforded bis-sulfonamides containing metal-complexing, polyamino-polycarboxylic acid moieties in their molecule. The corresponding mono-sulfonamide derivatives of dtpa were also obtained by an alternative method, from the free acid. Zn(II) complexes of these new sulfonamides were then prepared. Many of these derivatives showed nanomolar affinity towards isozymes I, II and IV of carbonic anhydrase (CA). Some of the best inhibitors were applied as 2% water solutions/suspensions into the eye of normotensive or glaucomatous albino rabbits, when strong and long-lasting intraocular pressure (IOP) lowering was observed.

Carbonic anhydrase inhibitors: perfluoroalkyl/aryl-substituted derivatives of aromatic/heterocyclic sulfonamides as topical intraocular pressure-lowering agents with prolonged duration of action

Reaction of perfluoroalkyl/arylsulfonyl chlorides or perfluoroalkyl/arylcarbonyl chlorides with aromatic/heterocyclic sulfonamides possessing a free amino/imino/hydrazino/hydroxy group afforded compounds with the general formula C(x)()F(y)()Z-A-SO(2)NH(2), where Z = SO(2)NH, SO(3), CONH, or CO(2) and A = aromatic/heterocyclic moiety. The sulfonyl chlorides used in synthesis included: CF(3)SO(2)Cl, n-C(4)F(9)SO(2)Cl, n-C(8)F(17)SO(2)Cl, and C(6)F(5)SO(2)Cl, whereas the acyl chlorides were C(8)F(17)COCl and C(6)F(5)COCl. A total of 25 different sulfonamides have been derivatized by means of the above-mentioned perfluorosulfonyl/acyl halides. These new series of sulfonamides showed strong affinities toward isozymes I, II, and IV of carbonic anhydrase (CA). For a given sulfonamide derivatized by the above procedures, inhibitory power was greater for the alkyl/arylsulfonylated compounds, as compared to the corresponding perfluoroalkyl/arylcarbonylated ones. In vitro inhibitory activity generally increased with the number of carbon atoms in the molecule of the acylating/sulfonylating agent, with a maximum for the perfluorophenylsulfonylated and perfluorobenzoylated derivatives. Some of the prepared CA inhibitors displayed very good water solubility (in the range of 2%) and strongly lowered intraocular pressure (IOP) when applied topically, directly into the normotensive/glaucomatous rabbit eye, as 2% water solutions. The good water solubility of these new classes of CA inhibitors, correlated with the neutral pH of their solutions used in the ophthalmologic applications, makes them attractive candidates for developing novel types of antiglaucoma drugs devoid of unpleasant ocular side effects.

Increased type II transforming growth factor-beta receptor expression in liver cells during cholesterol challenge

A large body of evidences implicates transforming growth factor-beta (TGF-beta) in the pathogenesis of atherosclerosis. In this context, TGF-beta receptor dysfunction has been suggested to be relevant. We tested the effect of hypercholesterolemia, a well-known risk factor for atherosclerosis, on liver type II TGF-beta receptor (TbetaR-II) expression in atherosclerosis-susceptible C57BL/6 mouse strain fed atherogenic diet. In addition, the relationship between cholesterol and TbetaR-II expression was verified by cholesterol challenge on human hepatoma cell (HepG2) cultures. The susceptible C57BL/6 mice fed atherogenic diet exhibited significant mRNA and immunohistochemical TbetaR-II liver expression at 2, 5, 9 and 15 weeks as compared to animals fed a regular diet. The TbetaR-II profile on HepG2 resulted in a time-dependent increased expression when the cells were incubated with soluble free cholesterol, associated with an increased TGF-beta-dependent biological activity as detected by luciferase assay of reporter gene. These data provide evidence for a cholesterol-dependent TbetaR-II induction that may play a potentially relevant role in the development of hypercholesterolemia and atherogenesis.

Carbonic anhydrase inhibitors. Synthesis of topically effective intraocular pressure lowering agents derived from 5-(omega-aminoalkylcarboxamido)-1,3,4-thiadiazole-2-sulfonamide

Reaction of the acyl chlorides of phthalimido-glycine or phthalimido-beta-alanine with 5-amino-1,3,4-thiadiazole-2-sulfonamide afforded after hydrazinolysis and deprotection of the phthalimido group the corresponding 5-(omega-aminoalkylcarboxamido)-1,3,4-thiadiazole-2-sulfonamides. Reaction of 5-(beta-aminoethylcarboxamido)-1,3,4-thiadiazole-2-sulfonamide with sulfonyl halides or acyl halides afforded a series of compounds possessing beta-alkyl/arylsulfonyl/carbonylamidoethylcarboxamido moieties in the 5 position of the thiadiazole-2-sulfonamide ring. The new derivatives were efficient inhibitors of three carbonic anhydrase (CA) isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form), but especially against CA II and CA IV (in nanomolar range), the two isozymes known to play an important role in aqueous humor secretion within the ciliary processes of the eye. Some of the synthesized inhibitors possessed good water solubility (as hydrochlorides or sodium salts) and were applied as 2% solutions directly into the eye of normotensive or glaucomatous albino rabbits. Very strong intraocular pressure (IOP) lowering was observed for many of them for prolonged periods of 1-2 h, and the active drug was detected in eye tissues and fluids indicating that the antiglaucoma effect is due to CA inhibition within the eye.

Carbonic anhydrase inhibitors - part 78(#). Synthesis of water-soluble sulfonamides incorporating beta-alanyl moieties, possessing long lasting-intraocular pressure lowering properties via the topical route

Reaction of 26 aromatic/heterocyclic sulfonamides containing amino, imino, hydrazino or hydroxyl groups with N-tert-butyloxycarbonyl-beta-alanine (Boc-beta-ala; Boc = t-butoxycarbonyl) in the presence of carbodiimide derivatives afforded, after removal of the protecting group, a series of water-soluble compounds (as salts of strong acids, such as hydrochloric, trifluoroacetic or trifluoromethane sulfonic). The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA), and more precisely of three of its isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form), involved in important physiological processes. Good inhibition was observed against all three isozymes, but especially against CA II and CA IV (in the nanomolar range), the two isozymes known to play a critical role in aqueous humour secretion within the ciliary processes of the eye. Some of the best inhibitors synthesized were applied as 2% aqueous solutions into the eyes of normotensive or glaucomatous albino rabbits, when strong and long-lasting intraocular pressure (IOP) lowering was observed with many of them. Thus, the amino acyl groups conferring water solubility to these sulfonamide CA inhibitors, coupled with their strong enzyme inhibitory properties and balanced lipid solubility seem to be the key factors for obtaining compounds with effective topical antiglaucoma activity.

Simultaneous interpretation of Mössbauer, EPR and 57Fe ENDOR spectra of the [Fe4S4] cluster in the high-potential iron protein I from Ectothiorhodospira halophila

Mössbauer spectra of the oxidized [Fe4S4]3+ and the reduced [Fe4S4]2+ clusters in the high-potential iron protein I from Ectothiorhodospira halophila were measured in a temperature range from 5 K to 240 K. EPR measurements and 57Fe electron-nuclear double resonance (ENDOR) experiments were carried out with the oxidized protein. In the oxidized state the cluster has a net spin S = 1/2 and is paramagnetic. As common in [Fe4S4]3+ clusters, the Mössbauer spectrum was simulated with two species contributing equally to the absorption area: two Fe3+ atoms couple to the "ferric-ferric" pair, and one Fe2+ and one Fe3+ atom give the "ferric-ferrous pair". For the simulation of the Mössbauer spectrum, g-values were taken from EPR measurements. A-tensor components were determined by 57Fe ENDOR experiments that turned out to be a necessary source of estimating parameters independently. In order to obtain a detailed agreement of Mössbauer and ENDOR data, electronic relaxation has to be taken into account. Relaxing the symmetry condition in a way that the electric field gradient tensor does not coincide with g- and A-tensors yielded an even better agreement of experimental and theoretical Mössbauer spectra. Spin-spin and spinlattice relaxation times were estimated by pulsed EPR; the former turned out to be the dominating mechanism at T = 5 K. Relaxation times measured by pulsed EPR and obtained from the Mössbauer fit were compared and yield nearly identical values. The reduced cluster has one additional electron and has a diamagnetic (S = 0) ground state. All the four irons are indistinguishable in the Mössbauer spectrum, indicating a mixed-valence state of Fe2.5+ for each.

Carbonic anhydrase inhibitors. Part 79. Synthesis of topically acting sulfonamides incorporating GABA moieties in their molecule, with long-lasting intraocular pressure-lowering properties

Reaction of 26 aromatic/heterocyclic sulfonamides containing amino, imino, hydrazino or hydroxyl groups with N-tert-butoxycarbonyl-gamma-aminobutyric acid (Boc-GABA; Boc=t-butoxycarbonyl) in the presence of carbodiimide derivatives, afforded after removal of the protecting group, a series of water-soluble compounds (as salts of strong acids, such as hydrochloric, trifluoroacetic or trifluoromethane sulfonic). The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA), and more precisely of three of its isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form), involved in important physiological processes. Some of the new compounds effectively inhibited CA II and CA IV (in the nanomolar range), the two isozymes known to play a critical role in aqueous humor secretion within the ciliary processes of the eye. Some of the best inhibitors obtained as described above were applied as 2% water solutions into the eye of normotensive or glaucomatous albino rabbits, when strong and long-lasting intraocular pressure (IOP) lowering has been evidenced. Thus, the amino acyl tail conferring water solubility to these sulfonamides, coupled with their strong enzyme inhibitory properties and balanced lipid solubility seem to be the key factors for obtaining compounds with effective topical antiglaucoma activity from the class of the carbonic anhydrase inhibitors.

Carbonic anhydrase inhibitors: synthesis of water-soluble, topically effective intraocular pressure lowering aromatic/heterocyclic sulfonamides containing 8-quinoline-sulfonyl moieties: is the tail more important than the ring?

Reaction of 20 aromatic/heterocyclic sulfonamides containing a free amino, imino, hydrazino or hydroxyl group, with 8-quinoline-sulfonyl chloride afforded a series of water-soluble (as hydrochloride or triflate salts) compounds. The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA), and more precisely of three of its isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form), involved in important physiological processes. Efficient inhibition was observed against all three isozymes, but especially against CA II (in nanomolar range), which is the isozyme known to play a critical role in aqueous humor secretion within the ciliary processes of the eye. Some of the best inhibitors synthesized were topically applied as 2% water solutions onto the eye of normotensive and glaucomatous albino rabbits, when strong and long-lasting intraocular pressure (IOP) lowering was observed with many of them. This result prompted us to reanalyze the synthetic work done by other groups for the design of water soluble, topically effective antiglaucoma sulfonamides. According to these researchers, the IOP lowering effect is due to the intrinsic nature of the specific heterocyclic sulfonamide considered, among which the thienothiopyran-2-sulfonamide derivatives represent the best studied case. Indeed, the first agents developed for such applications, such as dorzolamide, are derivatives of this ring system. In order to prove that the tail (in this case the 8-quinoline-sulfonyl moiety) conferring water solubility to a sulfonamide CA inhibitor is more important than the ring to which the sulfonamido group is grafted, we also prepared a dorzolamide derivative to which the 8-quinoline-sulfonyl moiety was attached. This new compound is quite water soluble as hydrochloride salt, behaves as a strong CA II inhibitor, and fared better than the parent molecule in lowering IOP in experimental animals. Thus, the tail conferring water solubility to such an enzyme inhibitor is more important for its topical activity as antiglaucoma drug than the heterocyclic/aromatic ring to which the sulfonamido moiety is grafted.

Carbonic anhydrase inhibitors. Water-soluble, topically effective intraocular pressure lowering agents derived from isonicotinic acid and aromatic/heterocyclic sulfonamides: is the tail more important than the ring?

Reaction of twenty aromatic/heterocyclic sulfonamides containing a free amino, imino, hydrazino or hydroxyl group, with isonicotinoyl chloride afforded a series of water-soluble compounds (as hydrochloride or triflate salts). The new derivatives were examined as inhibitors of three carbonic anhydrase (CA) isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form). Efficient inhibition was observed against all three isozymes, but especially against CA II and CA IV (K(I) in the nanomolar range), the two isozymes known to play a critical role in aqueous humor secretion within the ciliary processes of the eye. Some of the most potent inhibitors synthesized were applied as 2% water solutions directly into the eye of normotensive or glaucomatous albino rabbits. Very strong intraocular pressure (IOP) lowering was observed for many of them, and the active drug was detected in eye tissues and fluids. According to others the IOP lowering effect of topically effective antiglaucoma sulfonamides is due to the intrinsic nature of the specific heterocyclic sulfonamide considered, among which the thienothiopyran-2-sulfonamide derivatives represent the best studied case e.g. dorzolamide. In order to prove that the tail (in this case the isonicotinoyl moiety) conferring water solubility to a sulfonamide CA inhibitor is more important than the ring to which the sulfonamido group is grafted a dorzolamide derivative to which the isonicotinoyl moiety was attached was also prepared. This new compound is more water soluble than dorzolamide (as hydrochloride salt), behaves as a strong CA II inhibitor and acts similarly to the parent derivative in lowering IOP in experimental animals. Thus, it seems that the tail conferring water solubility is more important for topical activity as an antiglaucoma drug than the heterocyclic/aromatic ring to which the sulfonamido moiety is attached.

Carbonic anhydrase inhibitors: synthesis of water-soluble, aminoacyl/dipeptidyl sulfonamides possessing long-lasting intraocular pressure-lowering properties via the topical route

Reaction of 26 aromatic/heterocyclic sulfonamides containing amino, imino, hydrazino, or hydroxyl groups with Boc-Gly, Boc-Sar, TrS-Crt, or Boc-Gly-Gly (Sar = sarcosine, N-Me-Gly; Crt = creatine, N-amidinosarcosine; TrS = tritylsulfenyl; Boc = tert-butoxycarbonyl) in the presence of carbodiimide derivatives afforded after removal of the protecting groups a series of water-soluble compounds (as salts of strong acids, such as hydrochloric, trifluoroacetic, or trifluoromethanesulfonic). The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA) and more precisely of three of its isozymes, CA I, II (cytosolic forms), and IV (membrane-bound form), involved in important physiological processes. Efficient inhibition was observed against all three isozymes and especially against CA II and IV (in the nanomolar range), the two isozymes known to play a critical role in aqueous humor secretion within the ciliary processes of the eye. Some of the best inhibitors synthesized were applied as 2% water solutions into the eye of normotensive or glaucomatous albino rabbits, when strong and long-lasting intraocular pressure (IOP) lowering was observed with many of them. Thus, the aminoacyl/dipeptidyl tail conferring water solubility to these sulfonamide CA inhibitors coupled with strong enzyme inhibitory properties and balanced lipid solubility seem to be the key factors for obtaining compounds with effective topical antiglaucoma activity.

Carbonic anhydrase inhibitors. Part 71. Synthesis and ocular pharmacology of a new class of water-soluble, topically effective intraocular pressure lowering sulfonamides incorporating picolinoyl moieties

Reaction of 20 aromatic/heterocyclic sulfonamides containing a free amino, imino, hydrazino or hydroxyl group, with picolinic acid in the presence of carbodiimide derivatives afforded a series of water-soluble (as hydrochloride or triflate salts) compounds. The new derivatives were assayed as inhibitors of three carbonic anhydrase (CA) isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form). Efficient inhibition was observed against all three isozymes, but especially against CA II and CA IV (in nanomolar range), the two isozymes known to play a critical role in aqueous humor secretion within the ciliary processes of the eye. Some of the best inhibitors synthesized were applied as 2% water solutions directly into the eye of normotensive or glaucomatous albino rabbits. Very strong intraocular pressure (IOP) lowering was observed for many of them, and the active drug was detected in eye tissues and fluids. This result prompted us to reanalyze the synthetic work done by other groups for the design of water soluble, topically effective antiglaucoma sulfonamides. According to these researchers, the IOP lowering effect is due to the intrinsic nature of the specific heterocyclic sulfonamide considered, among which the thienothiopyran-2-sulfonamide derivatives represent the best studied case. Indeed, the first agents developed for such applications, such as dorzolamide, are derivatives of this ring system. In order to prove that the tail (in this case the picolinoyl moiety) conferring water solubility to a sulfonamide CA inhibitor is critically important for its topical effectiveness, similarly to the ring to which the sulfonamido group is grafted, we also prepared a dorzolamide derivative to which the picolinoyl moiety was attached. This new compound is more water soluble than dorzolamide (as hydrochloride salt), behaves as a strong CA II inhibitor, and acts similarly to the parent derivative in lowering IOP in experimental animals. Thus, it seems that the tail conferring water solubility is more important for topical activity as antiglaucoma drug, than the heterocyclic/aromatic ring to which the sulfonamido moiety is grafted.

Carbonic anhydrase inhibitors. Synthesis of water-soluble, topically effective, intraocular pressure-lowering aromatic/heterocyclic sulfonamides containing cationic or anionic moieties: is the tail more important than the ring?

Reaction of several aromatic/heterocyclic sulfonamides containing a free amino, imino, hydrazino, or hydroxyl group, with 2, 3-pyridinedicarboxylic anhydride or 2,6-pyridinedicarboxylic acid in the presence of carbodiimide derivatives, afforded two series of water-soluble (as hydrochloride, triflate, or carboxylate salts) compounds. The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA) and more precisely of three of its isozymes, CA I, II (cytosolic forms), and IV (membrane-bound form), involved in important physiological processes. Efficient inhibition was observed against all three isozymes, but especially against CA II and IV (in nanomolar range), the two isozymes known to play a critical role in aqueous humor secretion within the ciliary processes of the eye. Some of the best inhibitors synthesized were applied as 2% water solutions directly into the eye of normotensive and glaucomatous albino rabbits. Very strong and long-lasting intraocular pressure (IOP) lowering was observed with many of them. This result prompted us to reanalyze the synthetic work done by other groups for the design of water-soluble, topically effective antiglaucoma sulfonamides. According to these researchers, the IOP-lowering effect is due to the intrinsic nature of the specific heterocyclic sulfonamide considered, among which the thienothiopyran-2-sulfonamide derivatives represent the best-studied case. Indeed, the first agents developed for topical application, such as dorzolamide, are derivatives of this ring system. To prove that the tail (in this case the pyridinecarboxylic moieties) conferring water solubility to a sulfonamide CA inhibitor is more important than the ring to which the sulfonamido group is grafted, we also prepared dorzolamide derivatives incorporating such moieties. These new compounds possess good water solubility as hydrochloride or carboxylate salts, balanced by a relatively modest lipid solubility. They are strong CA II inhibitors and are able to lower IOP in experimental animals more than the parent derivatives. Our conclusion is that the tail conferring water solubility to such an enzyme inhibitor is more important for topical activity as an antiglaucoma drug, than the heterocyclic/aromatic ring to which the sulfonamido moiety is grafted.

Carbonic anhydrase inhibitors. Part 60(#). The topical intraocular pressure-lowering properties of metal complexes of a heterocyclic sulfonamide: influence of the metal ion upon biological activity

Metal complexes of a sulfonamide possessing strong carbonic anhydrase (CA) inhibitory properties have been obtained from the sodium salt of the sulfonamide or from the free sulfonamide in the presence of ammonia, and the following metal ions: Mg(II); Zn(II); Mn(II); Cu(II); Co(II); Ni(II); Be(II); Cd(II); Pb(II); Al(III); Fe(III) and La(III). The original sulfonamide, 5-(3,4-dichlorophenylureido)-1,3,4-thiadiazole-2-sulfonamide and its complexes were assayed for in vitro inhibition of three CA isozymes, CA I, II and IV, some of which play a critical role in ocular fluid secretion. All these compounds (the sulfonamide and its metal complexes) behave as very powerful inhibitors against the three investigated CA isozymes. The parent sulfonamide possesses strong topical pressure lowering effects in rabbits when applied as a 1% solution directly into the eye, but some of its metal complexes, such as the Mg(II); Zn(II); Mn(II) and Cu(II) derivatives, lower intraocular pressure (IOP) in experimental animals much better. Ex vivo data showed a 98.5-99.9% inhibition of CA II and IV in ocular fluids and tissues of the rabbits treated with these agents, proving that the IOP lowering properties are due to CA inhibition. The influence of the different metal ions upon the efficiency of the obtained complexes as pressure lowering drugs are discussed, considering the possibility to design in this way more selective pharmacological agents from this class.

Heregulin-dependent autocrine loop regulates growth of K-ras but not erbB-2 transformed rat thyroid epithelial cells

The EGF-like family of proteins, such as epidermal growth factor (EGF), transforming growth factor alpha (TGFalpha), amphiregulin (AR), betacellulin (BTC), cripto-1 (CR-1), and heregulin (HRG), plays an important role in the pathogenesis of several human carcinomas as autocrine growth factors. Differentiation and proliferation of rat thyroid cells in culture (FRTL-5 cells) are regulated by thyrotropin (TSH); withdrawal of TSH from culture medium produces growth arrest, whereas its addition to quiescent cells stimulates cell entry into S phase. Instead, transformed thyroid cell lines as FRTL-5H2 cell line, overexpressing erbB-2, Kimol cells, transformed by the wild-type K-ras and A6 clone, transformed by a temperature sensitive K-ras mutant, can grow without addition of TSH to the culture medium. In order to identify whether EGF-like growth factors and corresponding receptors (erbB-2, erbB-3, and erbB-4) could be involved in the autonomous growth of these transformed rat thyroid epithelial cells, Northern blot for mRNA analysis and Western blot for protein expression were performed. In contrast to normal control FRTL-5 cells, both K-ras and erbB-2-transformed cells expressed elevated levels of erbB-2 receptor. Moreover, both K-ras transformed cells, Kimol and A6 cells, but no FRTL-5H2 cells, were found able to express also high levels of erbB-4 receptor and HRG/NDF ligand. Treatment of K-ras transformed thyroid cells with neutralizing antibody against HRG/NDF reduced by 50% cell proliferation. These data indicate that unlike the erbB-2 overexpressing FRTL-5 cells, in K-ras rat thyroid epithelial cells, the growth factor heregulin signals through the heterodimer erbB-2/erbB-4 receptors in an autocrine fashion.

Carbonic anhydrase inhibitors: inhibition of isozymes I, II and IV with N-hydroxysulfonamides--a novel class of intraocular pressure lowering agents

A series of N-hydroxy sulfonamides has been prepared by reaction of alkyl-, arylalkyl- and arylsulfonyl halides or sulfonic acid anhydrides with hydroxylamine. Structurally related inhibitors were also obtained from acyl chlorides and hydroxylamine, as well as by reaction of tosyl isocyanate with hydroxylamine, sulfamic acid and sulfamide. Inhibition of three carbonic anhydrase (CA) isozymes, hCA I, hCA II and bCA IV (h = human; b = bovine) with the prepared compounds has been investigated. Good inhibitors, as well as compounds with moderate activity against these isozymes were detected, depending on the R group to which the SO2NHOH or CONHOH moieties were attached. Susceptibility to inhibition was generally: hCA II > bCA IV >> hCA I. Some of the new inhibitors showed very good antiglaucoma action when administered directly into the eye in experimental animals, acting as more efficient intraocular pressure lowering agents as compared to the clinical drug dorzolamide. This constitutes an encouraging result for obtaining novel antiglaucoma drugs from this class of CA inhibitors.

Cyclin D1 and Cyclin E expression in malignant thyroid cells and in human thyroid carcinomas

Evidence of the involvement of cyclin gene alterations in human cancer is growing. In this study, we sought to determine the pattern of expression of cyclin D1 and cyclin E in normal and malignant thyroid cells. Quiescent rat thyroid cells in culture, induced to synthesize DNA by thyrotropin (TSH), expressed cyclin D1 gene after 6 hr and cyclin E gene with a peak at 18 hr from the stimulus; K-ras-transformed rat thyroid cells, which grew without addition of hormones necessary for normal cell proliferation, expressed elevated levels of cyclin D1 and cyclin E, compared with normal differentiated thyroid cells. Human benign and malignant thyroid tumors and their relative normal tissues were then analyzed. Neither major genetic alterations nor amplifications for cyclin D1 and cyclin E genes were found by Southern blot analysis in genomic DNAs extracted from all types of thyroid tumors. Moreover, statistical analyses of densitometric values from Northern blots did not show increased levels of cyclin D1 and E mRNAs in the tumor samples, compared with normal thyroid. Immunohistochemical analyses of formalin-fixed paraffin-embedded sections of tissues with specific antibodies revealed a prevalent cytoplasmic cyclin E staining in the thyroid tissues analyzed. Cyclin D1, instead, was present in the cytoplasm of normal thyroids and adenomas, but in 31% of thyroid papillary carcinomas analysed, it was overexpressed, with a localization in the nucleus. Our in vivo observations suggest that unlike cyclin E, elevated nuclear cyclin D1 expression defines a subset of thyroid papillary carcinomas, and might be a contributory factor to thyroid tumorigenesis.

Oncogenes and antioncogenes involved in human thyroid carcinogenesis

The development of cancer is due to the accumulation of multiple somatic mutations, in some cases following germline mutations, which occur in hereditary malignancies such as retinoblastomas or multiple endocrine neoplasia (MEN 2A and B). Genetic alterations or changes in the expression of growth regulatory genes can lead to the initiation of malignant transformation and to eventual tumor progression. Cells that have undergone these cumulative alterations in either the structure or expression of these regulatory genes generally possess a selective growth and/or metastatic advantage over other normal non-transformed cells. Thus, activation of dominantly transforming oncogenes by point mutations, gene amplification, chromosomal translocation or insertional mutagenesis can lead to uncontrolled cellular growth or to a disruption in normal differentiation or apoptosis. Equally contributory to the process of malignant progression is the inactivation of recessive tumor suppressor genes due to point mutations and/or loss of heterozygosity in one allele, which can ultimately lead to a reduction of homozygosity in both alleles. Thyroid tumors in humans represent a particularly suitable multistage model of epithelial tumorigenesis. In fact, even though most thyroid neoplasms originate from a single cell type, i.e. the thyroid follicular cell, they include a broad spectrum of tumors with different phenotypic characteristics and variable biological and clinical behaviour. Multiple degrees of malignancies have been defined: from the benign colloid adenomas through the slowly progressive differentiated papillary and follicular carcinomas to the invariably fatal anaplastic carcinomas, although these histological changes are not necessarily sequential. In this review an effort has been made to summarize and integrate new data published on genetic lesions and altered expression of genes involved in the tumorigenesis of the follicular type of thyroid cancer. We have focused our interest only on gene alterations inducing gain or loss of function, that have been studied in vivo in human thyroid tumor specimens by the use of different techniques, such as PCR mediated DNA analyses, sequencing, mRNA level evaluation and protein expression by immunohistochemical staining.

Restored expression of transforming growth factor beta type II receptor in k-ras-transformed thyroid cells, TGF beta-resistant, reverts their malignant phenotype

Transforming growth factor beta 1 (TGF beta 1) inhibits the growth of normal rat epithelial thyroid cells (FRTL-5 strain) by counteracting thyrotropin (TSH)-stimulated DNA synthesis and by slowing the cells in the G1 phase of the cell cycle. Here, we have studied two clones of FRTL-5 thyroid cell line transformed by the wild type (wt) v-k-ras oncogene (K.M.A1, K.M.A2) and one clone (A6) transformed by a temperature-sensitive (ts) v-k-ras mutant. Anchorage-dependent as well as anchorage-independent growth of these k-ras-transformed cells was not inhibited by TGF beta 1. TGF beta 1 resistance appeared to be dependent by a functional p21 k-ras, because A6 cell growth was partially inhibited at the nonpermissive temperature (39 degrees C). To determine the basis for TGF beta 1 resistance in k-ras-transformed thyroid cells, we looked for possible defects in the expression of type I (T beta R-I/ALK5) and type II TGF beta receptors (T beta R-II). Lower levels of type II receptors were present in all of the k-ras-transformed clones, as revealed by both Northern blot and cross-linking experiments. A partial reversion of the malignant phenotype of the wt k-ras-transformed clone was obtained in two clones isolated after transfection of the malignant thyroid cells (K.M.A1) with a T beta R-II expression vector. These two clones also showed restored levels of exogenous T beta R-II mRNA and protein, and both clones showed a partially reacquired sensitivity to TGF beta 1. Similarly, the reversion of the malignant phenotype of the A6 clone grown at the nonpermissive temperature was accompanied by a restored expression of the T beta R-II receptors. These data indicate that active k-ras oncogene can induce TGF beta 1 resistance in rat thyroid cells and suggest that one of the possible mechanisms of escape from TGF beta 1 growth control in k-ras-induced thyroid carcinogenesis involves a reduced expression of T beta R-II receptors.

Increased transforming growth factor-beta production and gene expression by peripheral blood monocytes of hypertensive patients

Cultured human peripheral blood monocytes are known to secrete and express transforming growth factor-beta (TGF-beta), a multifunctional cytokine that can be involved in myocardial and vascular remodeling. In addition, monocytes/macrophages have been demonstrated to be colocalized with fibrosis of hypertrophied heart and in the vascular wall of hypertensive vessels. In this study, we tested TGF-beta production and mRNA expression in peripheral blood monocytes from hypertensive patients with myocardial hypertrophy and increased carotid myointimal thickness with respect to healthy normotensive control subjects. We found an increased TGF-beta activity in the conditioned medium of monocytes from hypertensive patients compared with control subjects as evaluated by inhibition of [3H]thymidine incorporation by mink lung epithelial cells (-83% and -18% in hypertensive and normotensive subjects; P<.001). Western blot analysis confirmed a significant difference in the amount of TGF-beta protein secreted in the conditioned medium of hypertensive patients compared with that of normotensive subjects. Finally, we also observed a 4.2- and 5.5-fold increase in the amount of TGF-beta1 and TGF-beta2 transcripts, respectively. Our results indicate an upregulation of the TGF-beta system in the peripheral blood monocytes of hypertensive patients with cardiovascular structural changes, suggesting a possible role of TGF-beta monocyte production in hypertensive disease.