DNA hypermethylation is associated with invasive phenotype of malignant melanoma

Tumor cell invasion is one of the key processes during cancer progression, leading to life-threatening metastatic lesions in melanoma. As methylation of cancer-related genes plays a fundamental role during tumorigenesis and may lead to cellular plasticity which promotes invasion, our aim was to identify novel epigenetic markers on selected invasive melanoma cells. Using Illumina BeadChip assays and Affymetrix Human Gene 1.0 microarrays, we explored the DNA methylation landscape of selected invasive melanoma cells and examined the impact of DNA methylation on gene expression patterns. Our data revealed predominantly hypermethylated genes in the invasive cells affecting the neural crest differentiation pathway and regulation of the actin cytoskeleton. Integrative analysis of the methylation and gene expression profiles resulted in a cohort of hypermethylated genes (IL12RB2, LYPD6B, CHL1, SLC9A3, BAALC, FAM213A, SORCS1, GPR158, FBN1 and ADORA2B) with decreased expression. On the other hand, hypermethylation in the gene body of the EGFR and RBP4 genes was positively correlated with overexpression of the genes. We identified several methylation changes that can have role during melanoma progression, including hypermethylation of the promoter regions of the ARHGAP22 and NAV2 genes that are commonly altered in locally invasive primary melanomas as well as during metastasis. Interestingly, the down-regulation of the methylcytosine dioxygenase TET2 gene, which regulates DNA methylation, was associated with hypermethylated promoter region of the gene. This can probably lead to the observed global hypermethylation pattern of invasive cells and might be one of the key changes during the development of malignant melanoma cells.     

Lateral organization of the ICAM-1 molecule at the surface of human lymphoblasts: A possible model for its co-distribution with the IL-2 receptor,class I and class II HLA molecules

Lateral distribution of the ICAM-1 molecule and its topological relationship (mutual proximity) to the heavy and light chains of class I HLA molecules, HLA-DR and interleukin-2 receptor α-chain (IL-2Rα) were studied in the plasma membrane of HUT-102B2 T and JY B lymphoblastoid cell lines by the technique of flow cytometric energy transfer (FCET). Effects of adherency and treatments with recombinant interferon-γ or tumor necrosis factor-α on the relative expression level of ICAM-1 to the above cell surface proteins were also investigated. While the cytokines did not significantly affect the ICAM-1 level of either cell line, an increased ICAM-1 expression was found on adherent JY cells. The ICAM-1 expression varied significantly with the cell cycle and culture conditions, as well. The statistical analysis of the differences observed in the energy transfer efficiency histograms resulted in a possible model of lateral co-distribution of these proteins in the plasma membrane. These two-dimensional patterns proved to be different for T and B lymphoma lines. ICAM-1 molecules showed a high degree of self-ssociation on HUT-102B2 (T) cells, while they were mainly expressed as monomers on the surface of JY (B) cells. Both cells showed a significant (ca. 30 %) difference between densities of the heavy and light chains of class I HLA antigen, suggesting a substantial amount of β2-microglobulin free heavy chains on these cell lines. The class I HLA molecules also showed partial self-association, but on both cell lines. The β₂-microglobulin and the heavy chain of the class I HLA showed strongly different proximities to the IL-2Rα, HLA-DR and ICAM-1 molecules, indicating that their orientations relative to the other proteins are dissimilar. IL-2Rα molecules of the HUT-102B2 (T) cells are located mostly in the vicinity of the β₂-microglobulin. In contrast, the local density of HLA-DR antigens is higher in the proximity of the heavy chain than in the vicinity of the β₂-microglobulin. The possible functional significance of these protein patterns is also discussed herein.     

Proadrenomedullin,a useful tool for risk stratification in high Pneumonia Severity Index score community acquired pneumonia

The aim of the present study was, first, to evaluate the prognostic value of mid-regional proadrenomedullin (proADM) in emergency department (ED) patients with a diagnosis of community acquired pneumonia (CAP) and, second, to analyze the added value of proADM as a risk stratification tool in comparison with other biomarkers and clinical severity scores.     

Induction of mesenchymal/epithelial marker expression in human amniotic fluid stem cells

Although dialysis and transplantation are widely applied therapies for renal failure, drawbacks such as morbidity, shortage of compatible organs and high cost are limiting factors. Recently, interest has increased in the potential use of stem cells for the repair of kidney injury, which has been considered as an alternative therapeutic strategy. Due to their high proliferation rates, their pluripotent differentiation potential, the finding that they do not induce tumour formation and the fact that they do not raise the ethical concerns connected with human embryonic stem cells, human amniotic fluid stem cells are considered to be a very promising cell source. This study demonstrates that the expression of the mesenchymal markers CD29 and CD44, the epithelial markers CD51 and ZO-1 and the podocyte markers CD2AP and NPHS2 can be induced in these cells via incubation with epidermal growth factor/platelet-derived growth factor BB and fibroblast growth factor 4/hepatocyte growth factor, respectively. Since podocytes are visceral epithelial cells in the kidneys, which form the essential part of the glomerular filtration barrier, these findings warrant further investigation of the potential use of human amniotic fluid stem cells for cell-based kidney therapies.     

Increased activity of Diaphanous homolog 3 (DIAPH3)/diaphanous causes hearing defects in humans with auditory neuropathy and in Drosophila

Auditory neuropathy is a rare form of deafness characterized by an absent or abnormal auditory brainstem response with preservation of outer hair cell function. We have identified Diaphanous homolog 3 (DIAPH3) as the gene responsible for autosomal dominant nonsyndromic auditory neuropathy (AUNA1), which we previously mapped to chromosome 13q21-q24. Genotyping of additional family members narrowed the interval to an 11-Mb, 3.28-cM gene-poor region containing only four genes, including DIAPH3. DNA sequencing of DIAPH3 revealed a c.-172G > A, g. 48G > A mutation in a highly conserved region of the 5′ UTR. The c.-172G > A mutation occurs within a GC box sequence element and was not found in 379 controls. Using genome-wide expression arrays and quantitative RT-PCR, we demonstrate a 2- to 3-fold overexpression of DIAPH3 mRNA in lymphoblastoid cell lines from affected individuals. Likewise, a significant increase (≈1.5-fold) in DIAPH3 protein was found by quantitative immunoblotting of lysates from lymphoblastoid cell lines derived from affected individuals in comparison with controls. In addition, the c.-172G > A mutation is sufficient to drive overexpression of a luciferase reporter. Finally, the expression of a constitutively active form of diaphanous protein in the auditory organ of Drosophila melanogaster recapitulates the phenotype of impaired response to sound. To date, only two genes, the otoferlin gene OTOF and the pejvakin gene PJVK, are known to underlie nonsyndromic auditory neuropathy. Genetic testing for DIAPH3 may be useful for individuals with recessive as well as dominant inheritance of nonsyndromic auditory neuropathy.     

Case of Pediatric Bullous Systemic Lupus Erythematosus Treated with Intravenous Immunoglobulin

This is a case report of a 16‐year‐old girl recently diagnosed with systemic lupus erythematosus (SLE) who presented with multiple blisters on the face, hands, arms, legs, trunk, and vaginal and oral mucosa. Skin biopsy was consistent with bullous SLE (BSLE). Dapsone is often the first‐line treatment option for BSLE, but the patient's history of anemia and leukopenia and long‐term immunosuppression requirement for her systemic symptoms raised concerns about dapsone and bone marrow toxicity, especially hemolytic anemia and agranulocytosis. She was started on intravenous immunoglobulin (IVIG), 2 g/kg divided over 3 days, with significant improvement in her cutaneous symptoms. IVIG is a treatment option for BSLE patients in whom agents such as dapsone are contraindicated.