Influence of immunomagnetic enrichment on gene expression of tumor cells

BACKGROUND: Metastasis is the leading cause of cancer-related death. Bone marrow (BM) is a frequent site for the settlement of disseminated tumor cells which occurs years before overt metastases signal incurability. METHODS: Here we describe a new method to assess the initial stage of metastasis development in cancer patients. By immunomagnetic selection with HER2/neu and EpCAM as catcher antigens single disseminated tumor cells can be enriched from BM samples. To examine whether the immunomagnetic enrichment technique may change gene expression in the selected tumor cells, we performed differential expression profiling with the breast cancer cell lines MCF-7 and BT474 as models. The profiles were performed using 1.2 Cancer Arrays (Clontech) containing 1176 cDNAs that can be grouped into different functional categories, such as signal transduction, cell cycle, adhesion, cytoskeleton plasticity, growth factors and others. RESULTS: The reproducibility of the gene expression profiling between duplicate cDNA-array experiments was assessed by two independent experiments with MCF-7 breast cancer cells. Scatter blot analysis revealed a good reproducibility of the cDNA array analysis (i.e. less than 10% difference in the gene expression between the arrays). Subsequent comparative cDNA-array analyses of immunobead-selected and unselected MCF-7 and BT474 cancer cells indicated that the antibody incubation during the immunomagnetic selection procedure did not considerably alter the gene expression profile. CONCLUSION: The described method offers an excellent tool for the enrichment of micrometastatic tumor cells in BM without largely changing the gene expression pattern of these cells

Reduced TRPC Channel Expression in Psoriatic Keratinocytes Is Associated with Impaired Differentiation and Enhanced Proliferation

Psoriasis is a characteristic inflammatory and scaly skin condition with typical histopathological features including increased proliferation and hampered differentiation of keratinocytes. The activation of innate and adaptive inflammatory cellular immune responses is considered to be the main trigger factor of the epidermal changes in psoriatic skin. However, the molecular players that are involved in enhanced proliferation and impaired differentiation of psoriatic keratinocytes are only partly understood. One important factor that regulates differentiation on the cellular level is Ca2+. In normal epidermis, a Ca2+ gradient exists that is disturbed in psoriatic plaques, favoring impaired keratinocyte proliferation. Several TRPC channels such as TRPC1, TRPC4, or TRPC6 are key proteins in the regulation of high [Ca2+]ex induced differentiation. Here, we investigated if TRPC channel function is impaired in psoriasis using calcium imaging, RT-PCR, western blot analysis and immunohistochemical staining of skin biopsies. We demonstrated substantial defects in Ca2+ influx in psoriatic keratinocytes in response to high extracellular Ca2+ levels, associated with a downregulation of all TRPC channels investigated, including TRPC6 channels. As TRPC6 channel activation can partially overcome this Ca2+ entry defect, specific TRPC channel activators may be potential new drug candidates for the topical treatment of psoriasis

The Flavonoid Luteolin Inhibits Fcγ-Dependent Respiratory Burst in Granulocytes, but Not Skin Blistering in a New Model of Pemphigoid in Adult Mice

Bullous pemphigoid is an autoimmune blistering skin disease associated with autoantibodies against the dermal-epidermal junction. Passive transfer of antibodies against BP180/collagen (C) XVII, a major hemidesmosomal pemphigoid antigen, into neonatal mice results in dermal-epidermal separation upon applying gentle pressure to their skin, but not in spontaneous skin blistering. In addition, this neonatal mouse model precludes treatment and observation of diseased animals beyond 2–3 days. Therefore, in the present study we have developed a new disease model in mice reproducing the spontaneous blistering and the chronic course characteristic of the human condition. Adult mice were pre-immunized with rabbit IgG followed by injection of BP180/CXVII rabbit IgG. Mice pre-immunized against rabbit IgG and injected 6 times every second day with the BP180/CXVII-specific antibodies (n = 35) developed spontaneous sustained blistering of the skin, while mice pre-immunized and then treated with normal rabbit IgG (n = 5) did not. Blistering was associated with IgG and complement C3 deposits at the epidermal basement membrane and recruitment of inflammatory cells, and was partly dependent on Ly-6G-positive cells. We further used this new experimental model to investigate the therapeutic potential of luteolin, a plant flavonoid with potent anti-inflammatory and anti-oxidative properties and good safety profile, in experimental BP. Luteolin inhibited the Fcγ-dependent respiratory burst in immune complex-stimulated granulocytes and the autoantibody-induced dermal-epidermal separation in skin cryosections, but was not effective in suppressing the skin blistering in vivo. These studies establish a robust animal model that will be a useful tool for dissecting the mechanisms of blister formation and will facilitate the development of more effective therapeutic strategies for managing pemphigoid diseases

Molecular signature associated with bone marrow micrometastasis in human breast cancer

Metastasis is the leading cause of cancer-related death, and bone marrow (BM) is a prominent metastatic site in solid tumors. Here, we focused on the onset of metastasis, using BM as an indicator organ for micrometastatic tumor cells in breast cancer patients without overt metastases (tumor-node-metastasis stage M0). Expression analysis with cDNA arrays showed distinct profiles between primary tumors from BM-positive and BM-negative patients. The differentially expressed genes are involved in extracellular matrix remodeling, adhesion, cytoskeleton plasticity, and signal transduction (in particular RAS and hypoxia-inducible factor la pathway). The BM signature was mainly characterized by transcriptional repression and different from the expression signature associated with lymphatic metastasis. Thus, BM micrometastasis is a selective process with a specific molecular signature of the primary tumor

Influence of traditionally used Nepalese plants on wound healing and immunological properties using primary human cells in vitro

Ethnopharmacological relevance: The improvement of wound healing has always been an important issue for both ethnopharmacological and modern medical research. In this study, we used state-of-the-art methods to investigate extracts of plants used traditionally in Nepal for more than 1000 years to treat inflammatory injuries. Aim of the study: We focused on the potential of the plant extracts to ameliorate wound healing and to influence immune modulatory properties. Materials and methods: Nine Nepalese plant extracts in three different solvents (methanol, ethyl acetate, petroleum ether) were immunologically characterised. Water-soluble tetrazolium (WST-1) assays and scratch assays were performed to determine their impact on viability and wound healing capacity of human keratinocytes and fibroblasts. Effects on proliferation, viability and function of physiologically relevant anti-CD3 and anti-CD28 stimulated primary human T lymphocytes were assessed using carboxyfluorescein succinimidyl ester (CFSE), annexin V/propidium iodide staining assays and flow cytometry-based surface receptor characterisation. The secretion level of interleukin-2 (IL-2) was analysed with the ELISA technique. Dendritic cells were generated out of peripheral blood mononuclear cells (PBMC) by CD14(+) magnetic bead selection. Flow cytometry-based surface receptor characterisation and ELISA-based technique were used to evaluate the DC activation state and the interleukin-8 (IL-8) secretion level. Results: We demonstrate that an ethyl acetate extract of Bassia longifolia and of Gmelina arborea have anti-inflammatory capacities, indicated by reduced proliferation, inhibition of IL-2 secretion and degranulation capacity of activated human T cells, when compared with adequate concentrations of synthetic positive drug controls. Furthermore, Gmelina arborea improved the wound healing of keratinocytes and fibroblasts and has tendency to increase the secretion of IL-8 by human primary dendritic cells. Conclusion: With this preliminary screening, we offer a scientific basis for the immunomodulatory properties of the two Nepalese medicinal plants Bassia longifolia and Gmelina arborea. However, further detailed studies regarding the responsible compounds are necessary