Canine sterile neutrophilic dermatosis (resembling Sweet's syndrome) with severe extracutaneous manifestations.

INTRODUCTION: Sterile neutrophilic dermatosis is a rare disease in dogs, similar to Sweet's syndrome in humans. This case report describes the treatment of a 2-year old Bearded Collie that was presented with a 3-week history of fever, hind-limb weakness, peripheral lymphadenomegaly and leucocytosis. Blood tests revealed severe leukocytosis, renal azotaemia, elevated liver enzymes and bilirubinaemia. Skin lesions started to appear in week four. Histology revealed a sterile neutrophilic dermatitis resembling Sweet's syndrome. The dog displayed extracutaneous manifestations, including fever, polyarthritis, a severe leukemoid reaction, anaemia, hepatopathy and nephropathy. Issues regarding the use of criteria for the diagnosis of Sweet's syndrome in humans that are used for dogs with sterile neutrophilic dermatosis, are discussed in this case report. The condition resolved with dexamethasone and mycophenolate mofetil as a novel steroid-sparing therapy. Three months later the dog relapsed, which rapidly responded to short-term dexamethasone treatment and temporarily increased mycophenolate mofetil dosage.

INTRODUCTION: La dermatose neutrophilique stérile est une maladie rare chez le chien, semblable au syndrome de Sweet chez l'homme. Ce rapport de cas décrit le traitement d'un Bearded Collie de 2 ans présentant des antécédents de fièvre pendant 3 semaines, une faiblesse des membres postérieurs, une lymphadénomégalie périphérique et une leucocytose. Les analyses de sang ont révélé une leucocytose grave, une azotémie rénale, une élévation des enzymes hépatiques et une bilirubinémie. Des lésions cutanées ont commencé à apparaître à la quatrième semaine. L'histologie a révélé une dermatite neutrophilique stérile ressemblant au syndrome de Sweet. Le chien présentait des manifestations extracutanées telles que fièvre, polyarthrite, réaction leucémoïde sévère, anémie, hépatopathie et néphropathie. Les questions relatives à l'utilisation des critères de diagnostic du syndrome de Sweet chez l'homme chez les chiens atteints de dermatose neutrophilique stérile sont abordées dans le présent rapport de cas. La maladie a été traitée avec la dexaméthasone et le mycophénolate mofétil en tant que thérapie innovante permettant d'économiser des stéroïdes. Trois mois plus tard, le chien a rechuté mais a rapidement répondu à un traitement de courte durée à la dexaméthasone et à une augmentation temporairement la dose de mycophénolate mofétil.

Isolation of stem/progenitor cells from normal lung tissue of adult humans.

OBJECTIVES: This study aimed to isolate and characterize stem/progenitor cells, starting from normal airway epithelia, obtained from human adults. MATERIALS AND METHODS: Cultures of multicellular spheroids were obtained from human lung tissue specimens after mechanical and enzymatic digestion. Tissue-specific markers were detected on their cells by immunohistochemical and immunofluorescent techniques. Ultrastructural morphology of the spheroids (termed as bronchospheres) was evaluated by electron microscopy, gene expression analysis was performed by reverse transcription-polymerase chain reaction, and gene down-regulation was analysed by an RNA interference technique. RESULTS: Bronchospheres were found to be composed of cells with high expression of stem cell regulatory genes, which was not or was only weakly detectable in original tissues. Morphological analysis showed that bronchospheres were composed of mixed phenotype cells with type II alveolar and Clara cell features, highlighting their airway resident cell origin. In addition to displaying specific pulmonary and epithelial commitment, bronchospheres showed mesenchymal features. Silencing of the Slug gene, known to play a pivotal role in epithelial-mesenchymal transition processes and which was highly expressed in bronchospheres but not in original tissue, led bronchospheres to gain a differentiated bronchial/alveolar phenotype and to lose the stemness gene expression pattern. CONCLUSIONS: Ours is the first study to describe ex vivo expansion of stem/progenitor cells resident in human lung epithelia, and our results suggest that the epithelial-mesenchymal transition process, still active in a subset of airway cells, may regulate transit of stem/progenitor cells towards epithelial differentiation.

Role of p53 codon 72 arginine allele in cell survival in vitro and in the clinical outcome of patients with advanced breast cancer.

BACKGROUND: The p53 codon 72 polymorphism, which results in either an arginine or proline residue, plays a different role in vitro and in vivo in cell survival and drug resistance. We verified, in vitro, the impact of the arginine allele on cell survival under normoxia and hypoxia, and investigated in vivo the role of p53 codon 72 arginine homozygosity in the clinical outcome of advanced breast cancer patients. METHODS: Tumors at advanced stages grow in vivo in a hypoxic environment, and we mimicked such conditions in vitro using p53 null breast cancer cells transfected with either the arginine or proline allele. We also analyzed in vivo the p53 codon 72 genotype status of advanced breast cancer patients. RESULTS: In vitro transfection of the arginine allele induced higher cell death under normoxia, whereas cell death was greater in proline-transfected cells under hypoxia. The arginine allele upregulated BCRP-I, a hypoxia response gene, which increases drug resistance. Metastatic breast cancer patients homozygous for arginine had a significantly shorter time to progression and overall survival than those with heterozygous arginine/proline tumors. CONCLUSION: We provide a molecular explanation for the association of the arginine allele with tumor aggressiveness and treatment resistance in advanced breast cancer.

Pro-apoptotic activity of cyclopentenone in cancer cells.

Studies on cyclopentenone prostaglandins (CPPGs), clavulones and other cyclopentenones have shown that these compounds have a significant anticancer activity mediated by their cyclopentenone (CP) chemical moiety. In this study the cytotoxicity against cancer cells of the model compound cyclopent-2-en-1-one (2CP) was investigated. Being a highly water soluble small molecule, 2CP could be an ideal candidate to overcome pharmacological issues related to drug delivery and penetration. Its cytotoxic activity was tested on various melanoma and lung cancer cells. Interestingly, 2CP was both cytotoxic and pro-apoptotic, more pronounced on melanoma cells, at concentrations in the sub-micromolar range. On melanoma cells its mechanism of action was mediated by the mitochondria and the activation of caspase 3.

Pro-apoptotic effect of a nitric oxide-donating NSAID, NCX 4040, on bladder carcinoma cells.

Nitric oxide-releasing non steroidal anti-inflammatory drugs (NO-NSAIDs) are a promising class of compounds that cause cell cycle perturbations and induce apoptosis in cell lines from different tumors. We investigated the activity of a recently developed NO-NSAID (NCX 4040) in bladder cancer cell lines (HT1376 and MCR). Cells were treated with different drug concentrations for different exposure times. Cytostatic and cytocidal activity was tested by SRB assay and apoptosis was evaluated by TUNEL analysis, ANNEXIN V assay and fluorescence microscopy. To further investigate the cell death-inducing mechanisms of NCX 4040, we analyzed gp-170, caspase expression and mitochondrial membrane potential (Delta Psi) depolarization. NCX 4040 showed a striking cytocidal activity in both cell lines, reaching LC(50) at a 10-microM and 50-microM concentrations in HT1376 and in MCR cells, respectively, after an exposure of only 6 h followed by an 18-h washout. Apoptosis was triggered in up to 90% of cells and was associated with active caspase-3 expression and Delta Psi depolarization in both cell lines after a 6-h exposure. In conclusion, NCX 4040, which probably causes apoptosis via a mitochondrial-dependent mechanism, could prove to be a useful agent for improving bladder cancer treatment.

Modulation of drug cytotoxicity by Iressa (ZD1839) in pancreatic cancer cell lines.

High expression of the epidermal growth factor receptor (EGFR) family confers a growth advantage on malignant cells in various tumor types. Most pancreatic cancers express EGFR, which seems to play an important role in the acquisition of aggressive clinical behaviour and in tumor invasion. Iressa (ZD1839), a quinazoline tyrosine kinase inhibitor selective for the EGF receptor, has shown good anti-tumor activity in both preclinical and clinical studies. Using two pancreatic cancer cell lines that express different EGFR and ErbB-2 levels, we analyzed the activity of Iressa and evaluated its modulation effect on four conventional cytotoxic drugs: gemcitabine, oxaliplatin, docetaxel and SN38. Iressa was tested at scalar doses up to the plasma peak level concentration and showed a similar weak cytostatic effect in both cell lines. Conversely, an additive or weak synergistic effect was observed when the drug was administered simultaneously with or following cytotoxic drugs. Our data show that Iressa has only a weak activity at doses within the plasmatic peak concentration and that its effect is independent of EGFR and p42/p44 expression and phosphorylation levels. This is in agreement with recent literature data that attribute an essential role to a specific EGFR mutation in mediating response to Iressa. This mutation was absent in both pancreatic cell lines tested.

The different apoptotic potential of the p53 codon 72 alleles increases with age and modulates in vivo ischaemia-induced cell death.

A common arginine to proline polymorphism is harboured at codon 72 of the human p53 gene. In this investigation, we found that fibroblasts and lymphocytes isolated from arginine allele homozygote centenarians and sexagenarians (Arg+) undergo an oxidative-stress-induced apoptosis at a higher extent than cells obtained from proline allele carriers (Pro+). At variance, the difference in apoptosis susceptibility between Arg+ and Pro+ is not significant when cells from 30-year-old people are studied. Further, we found that Arg+ and Pro+ cells from centenarians differ in the constitutive levels of p53 protein and p53/MDM2 complex, as well as in the levels of oxidative stress-induced p53/Bcl-xL complex and mitochondria-localised p53. Consistently, all these differences are less evident in cells from 30-year-old people. Finally, we investigated the in vivo functional relevance of the p53 codon 72 genotype in a group of old patients (66-99 years of age) affected by acute myocardial ischaemia, a clinical condition in which in vivo cell death occurs. We found that Arg+ patients show increased levels of Troponin I and CK-MB, two serum markers that correlate with the extent of the ischaemic damage in comparison to Pro+ patients. In conclusion, these data suggest that p53 codon 72 polymorphism contributes to a genetically determined variability in apoptotic susceptibility among old people, which has a potentially relevant role in the context of an age-related pathologic condition, such as myocardial ischaemia.