Human secreted proteins SLURP-1 and SLURP-2 control the growth of epithelial cancer cells via interactions with nicotinic acetylcholine receptors.

BACKGROUND AND PURPOSE: Nicotinic acetylcholine receptors (nAChRs) are a promising target for development of new anticancer therapies. Here we have investigated the effects of the endogenous human proteins SLURP-1 and SLURP-2, antagonists of nAChRs, on human epithelial cancer cells. EXPERIMENTAL APPROACH: Growth of epithelial cancer cells (A431, SKBR3, MCF-7, A549, HT-29) exposed to SLURP-1, SLURP-2, mecamylamine, atropine, timolol and gefitinib was measured by the WST-1 test. Expression levels of SLURP-1, α7-nAChR and EGF receptors and their distribution in cancer cells were studied by confocal microscopy and flow cytometry. Secretion of endogenous SLURP-1 by A431 cells under treatment with recombinant SLURP-1 was analysed by Western-blotting. KEY RESULTS: SLURP-1 and SLURP-2 significantly inhibited growth of A431, SKBR3, MCF-7 and HT-29 cells at concentrations above 1 nM, to 40-70% of the control, in 24 h. Proliferation of A549 cells was inhibited only by SLURP-1. The anti-proliferative activity of SLURPs on A431 cells was associated with nAChRs, but not with ß-adrenoceptors or EGF receptors. Action of gefitinib and SLURPs was additive and resulted almost complete inhibition of A431 cell proliferation during 24 h. Exposure of A431 cells to recombinant SLURP-1 down-regulated α7-nAChR expression and induced secretion of endogenous SLURP-1 from intracellular depots, increasing its concentration in the extracellular media. CONCLUSIONS AND IMPLICATIONS: SLURPs inhibit growth of epithelial cancer cells in vitro and merit further investigation as potential agents for anticancer therapy. LINKED ARTICLES: This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc.

Time- and concentration-dependent genomic responses of the rat airway to inhaled nickel sulfate.

While insoluble nickel subsulfide (Ni3 S2 ) was carcinogenic in the lung in a 2-year rat bioassay, soluble nickel sulfate hexahydrate (NiSO4* 6H2 O) was not. To investigate whether differences in the cellular responses to these two nickel compounds could underlie their differential activities, we conducted parallel studies to determine the gene expression changes in micro-dissected lung distal airway cells from Fischer 344 rats following inhalation of the two compounds for one and four weeks (6 hr per day, 5 days per week). The results of the Ni3 S2 study have been reported previously; this paper reports the results for NiSO4 and provides a comparative analysis. The cellular responses to NiSO4 were highly similar to those previously reported for Ni3 S2 , and a set of genes was identified whose expression could be used as biomarkers for comparing cellular nickel effects from in vitro or in vivo studies with soluble NiSO4 and particulate Ni3 S2 . Evaluation of the genomic concentration-responses for the two compounds suggests that the highest inhaled concentration in the tumor bioassay for NiSO4 , which was limited by toxicity, may not have achieved the Ni concentrations at which tumors were observed in the Ni3 S2 bioassay. However, several key differences in the immune responses to NiSO4 and Ni3 S2 were identified that may result from the differential intracellular disposition of Ni from NiSO4 entering the cell as an ion rather than as a slowly soluble Ni3 S2 particle. These differences may also contribute to the observation of tumors in the bioassay for Ni3 S2 but not NiSO4 . Environ. Mol. Mutagen. 58:607-618, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.

[THEORETICAL ASPECTS OF CREATION OF SPECIFIC PREPARATIONS FOR ETIOTROPIC THERAPY AND PROPHYLAXIS OF WEST NILE FEVER AND CRIMEAN HAEMORRHAGIC FEVER].

Problematic issues on creation and practical introduction of specific immune biologic prepa- rations for therapy and prophylaxis of natural-foci arbovirus infections - West Nile fever (WNF) and Crimean hemorrhagic fever (CHF), that are not available until now, are examined. Persistent natural foci of WNF and.CHF with epidemic manifestations have formed in Southern and North Caucasian Federal Districts of Russia. Markers of West Nile virus are being detected in central regions of Russia and Siberia, and the presence of fraction of population immune to this infection is also detected. Analysis, of literature sources that has been carried out forms a theoretical basis for creation ofnovel specific preparations for etiotropic, therapy and prophylaxis ofWNF and CHE. Use of blood from healthy donors with sufficiently high titers of class G immunoglobulins residing in certain subjects of Russian Federation in natural foci territories with the most intensive epidemic process is possible as raw material.

Distinct impact of targeted actin cytoskeleton reorganization on mechanical properties of normal and malignant cells.

The actin cytoskeleton is substantially modified in cancer cells because of changes in actin-binding protein abundance and functional activity. As a consequence, cancer cells have distinctive motility and mechanical properties, which are important for many processes, including invasion and metastasis. Here, we studied the effects of actin cytoskeleton alterations induced by specific nucleation inhibitors (SMIFH2, CK-666), cytochalasin D, Y-27632 and detachment from the surface by trypsinization on the mechanical properties of normal Vero and prostate cancer cell line DU145. The Young's modulus of Vero cells was 1300±900 Pa, while the prostate cancer cell line DU145 exhibited significantly lower Young's moduli (600±400 Pa). The Young's moduli exhibited a log-normal distribution for both cell lines. Unlike normal cells, cancer cells demonstrated diverse viscoelastic behavior and different responses to actin cytoskeleton reorganization. They were more resistant to specific formin-dependent nucleation inhibition, and reinforced their cortical actin after detachment from the substrate. This article is part of a Special Issue entitled: Mechanobiology.

Transcriptional responses in the rat nasal epithelium following subchronic inhalation of naphthalene vapor.

Male and female Fischer 344 rats were exposed to naphthalene vapors at 0 (controls), 0.1, 1, 10, and 30ppm for 6h/d, 5 d/wk, over a 90-day period. Following exposure, the respiratory epithelium and olfactory epithelium from the nasal cavity were dissected separately, RNA was isolated, and gene expression microarray analysis was conducted. Only a few significant gene expression changes were observed in the olfactory or respiratory epithelium of either gender at the lowest concentration (0.1ppm). At the 1.0ppm concentration there was limited evidence of an oxidative stress response in the respiratory epithelium, but not in the olfactory epithelium. In contrast, a large number of significantly enriched cellular pathway responses were observed in both tissues at the two highest concentrations (10 and 30ppm, which correspond to tumorigenic concentrations in the NTP bioassay). The nature of these responses supports a mode of action involving oxidative stress, inflammation and proliferation. These results are consistent with a dose-dependent transition in the mode of action for naphthalene toxicity/carcinogenicity between 1.0 and 10ppm in the rat. In the female olfactory epithelium (the gender/site with the highest incidences of neuroblastomas in the NTP bioassay), the lowest concentration at which any signaling pathway was significantly affected, as characterized by the median pathway benchmark dose (BMD) or its 95% lower bound (BMDL) was 6.0 or 3.7ppm, respectively, while the lowest female olfactory BMD values for pathways related to glutathione homeostasis, inflammation, and proliferation were 16.1, 11.1, and 8.4ppm, respectively. In the male respiratory epithelium (the gender/site with the highest incidences of adenomas in the NTP bioassay), the lowest pathway BMD and BMDL were 0.4 and 0.3ppm, respectively, and the lowest male respiratory BMD values for pathways related to glutathione homeostasis, inflammation, and proliferation were 0.5, 0.7, and 0.9ppm, respectively. Using a published physiologically based pharmacokinetic (PBPK) model to estimate target tissue dose relevant to the proposed mode of action (total naphthalene metabolism per gram nasal tissue), the lowest transcriptional BMDLs from this analysis equate to human continuous naphthalene exposure at approximately 0.3ppm. It is unlikely that significant effects of naphthalene or its metabolites will occur at exposures below this concentration.

Time- and concentration-dependent genomic responses of the rat airway to inhaled nickel subsulfide.

OBJECTIVE: To provide insights into the mode of action for Ni3S2 lung carcinogenicity by examining gene expression changes in target cells after inhalation exposure. METHODS: Gene expression changes were determined in micro-dissected lung broncho-alveolar cells from Fischer 344 rats following inhalation of Ni3S2 at 0.0, 0.04, 0.08, 0.15, and 0.60 mg/m(3) (0.03, 0.06, 0.11, and 0.44 mgNi/m(3)) for one and four weeks (6h/day, 5 days/week). RESULTS: Broncho-alveolar lavage fluid evaluation and lung histopathology provided evidence of inflammation only at the two highest concentrations, which were similar to those tested in the 2-year bioassay. The number of statistically significant up- and down-regulated genes decreased markedly from one to four weeks of exposure, suggesting adaptation. Cell signal pathway enrichment at both time-points primarily reflected responses to toxicity, including inflammatory and proliferative signaling. While proliferative signaling was up-regulated at both time points, some inflammatory signaling reversed from down-regulation at 1 week to up-regulation at 4 weeks. CONCLUSIONS: These results support a mode of action for Ni3S2 carcinogenicity driven by chronic toxicity, inflammation and proliferation, leading to mis-replication, rather than by direct genotoxicity. Benchmark dose (BMD) analysis identified the lowest pathway transcriptional BMD exposure concentration as 0.026 mgNi/m(3), for apoptosis/survival signaling. When conducted on the basis of lung Ni concentration the lowest pathway BMD was 0.64 µgNi/g lung, for immune/inflammatory signaling. IMPLICATIONS: These highly conservative BMDs could be used to derive a point of departure in a nonlinear risk assessment for Ni3S2 toxicity and carcinogenicity.