Background E-cigarettes or electronic nicotine delivery systems (ENDS) are designed to deliver nicotine-containing aerosol via inhalation. Little is known about the health effects of flavored ENDS aerosol when inhaled. Methods Aerosol from ENDS was generated using a smoking-machine. Various types of ENDS devices or a tank system prefilled with liquids of different flavors, nicotine carrier, variable nicotine concentrations, and with modified battery output voltage were tested. A convenience sample of commercial fluids with flavor names of tobacco, piña colada, menthol, coffee and strawberry were used. Flavoring chemicals were identified using gas chromatography/mass spectrometry. H292 human bronchial epithelial cells were directly exposed to 55 puffs of freshly-generated ENDS aerosol, tobacco smoke, or air (controls) using an air-liquid interface system and the Health Canada intense smoking protocol. The following in vitro toxicological effects were assessed: 1) cell viability, 2) metabolic activity and 3) release of inflammatory mediators (cytokines). Results Exposure to ENDS aerosol resulted in decreased metabolic activity and cell viability and increased release of IL-1β, IL-6, IL-10, CXCL1, CXCL2 and CXCL10 compared to air controls. Cell viability and metabolic activity were more adversely affected by conventional cigarettes than most tested ENDS products. Product type, battery output voltage, and flavors significantly affected toxicity of ENDS aerosol, with a strawberry-flavored product being the most cytotoxic. Conclusions Our data suggest that characteristics of ENDS products, including flavors, may induce inhalation toxicity. Therefore, ENDS users should use the products with caution until more comprehensive studies are performed.

Dietary isothiocyanates (ITCs) are highly effective in affording protection against chemically induced cancers in laboratory animals. In the present study, we demonstrate that allyl isothiocyanate (AITC), a constituent of cruciferous vegetables, significantly inhibits proliferation of cultured PC-3 (androgen-independent) and LNCaP (androgen-dependent) human prostate cancer cells in a dose-dependent manner with an IC(50) of approximately 15-17 micro M. On the other hand, survival of a normal prostate epithelial cell line (PrEC) was minimally affected by AITC even at concentrations that were highly cytotoxic to the prostate cancer cells. Reduced proliferation of PC-3 as well as LNCaP cells in the presence of AITC correlated with accumulation of cells in G(2)/M phase and induction of apoptosis. In contrast, AITC treatment failed to induce apoptosis or cause G(2)/M phase arrest in PrEC cells. A 24 h treatment of PC-3 and LNCaP cells with 20 micro M AITC caused a significant decrease in the levels of proteins that regulate G(2)/M progression, including Cdk1 (32-50% reduction), Cdc25B (44-48% reduction) and Cdc25C (>90% reduction). A significant reduction in the expression of cyclin B1 protein (approximately 45%) was observed only in LNCaP cells. A 24 h exposure of PC-3 and LNCaP cells to an apoptosis-inducing concentration of AITC (20 micro M) resulted in a significant decrease (31-68%) in the levels of anti-apoptotic protein Bcl-2 in both cell lines, and approximately 58% reduction in Bcl-X(L) protein expression in LNCaP cells. In conclusion, it seems reasonable to hypothesize that AITC, and possibly other ITCs, may find use in the treatment of human prostate cancers.

Estrogen receptor (ER) agonists and antagonists elicit distinct responses in non-small cell lung cancer (NSCLC) cells. To determine how such responses are generated, the expression of ERa a, ERh h, and ER coregulators in human lung fibroblasts and human NSCLC cell lines was evaluated by immunoblot. Ligand-dependent estrogenic responses in NSCLC cells are probably generated via ERB and the p160 coactivator GRIP1/ TIF2, because expression of these proteins was detected, but not full-length ERA or the p160 coactivator SRC-1. ERB and GRIP1/TIF2 are shown to interact in vitro in a liganddependent manner and thus may form functional transcription complexes in NSCLC cells. Furthermore, the capacity of ER ligands to regulate gene expression in NSCLC cells was explored using gene miniarrays. Expression profiles were examined after treatment with ER agonist 17-B-estradiol (E2), the pure ER antagonist ICI 182,780 ( fulvestrant, Faslodex), or epidermal growth factor, which served as a positive control for an alternative growth stimulus. E-cadherin and inhibitor of differentiation 2 were differentially regulated by E2 versus ICI 182,780 in 201T and 273T NSCLC cell lines. Epidermal growth factor also stimulated proliferation of these cells but had no effect on expression of E-cadherin and inhibitor of differentiation 2, suggesting they are specific targets of ER signaling. These data show that NSCLC cells respond to estrogens/antiestrogens by altering endogenous gene expression and support a model in which ICI 182,780 reduces proliferation of NSCLC cells via its ability to disrupt ER signaling. ICI 182,780 may therefore have therapeutic benefit in NSCLC. (Cancer Res 2005; 65(4): 1598-605)

(1,25-D 3 ), is inhibition of cell growth and induction of cell differentiation and/or apoptosis. Synthesis and degradation of the secosteroid occurs not only in the kidney but also in normal tissue or malignant extrarenal tissues such as the colon. Because 25-hydroxyvitamin D 3 24-hydroxylase (CYP24A1) is considered to be the main enzyme determining the biological half-life of 1,25-D 3 , we have examined expression of the CYP24A1 mRNA (by real-time RT-PCR) and protein (by immunohistochemistry) in normal human colon mucosa, colorectal adenomas, and adenocarcinomas in 111 patients. Although 76% of the normal and benign colonic tissue was either completely devoid of or expressed very low levels of CYP24A1, in the majority of the adenocarcinomas (69%), the enzyme was present at high concentrations. A parallel increased expression of the proliferation marker Ki-67 in the same samples suggests that overexpression of CYP24A1 reduced local 1,25-D 3 availability, decreasing its antiproliferative effect. (J Histochem Cytochem 58:277-285, 2010) COLORECTAL CANCER (CRC) is the second leading cause of malignant mortality in Western industrialized countries (Boyle and Ferlay 2005). Geographical distribution of cancer mortality in the US correlates with exposure to solar (ultraviolet B) radiation; the highest mortality rates for CRC were observed in regions with less solar radiation (Freedman et al. 2002). Furthermore, epidemiological data have shown an inverse association of serum 25-hydroxyvitamin D 3 (25-D 3 ) levels with risk for prostate, breast, and colorectal malignancies (Garland et al. 1989;Ahonen et al. 2000;Bertone-Johnson et al. 2005). Estimating premature cancer mortality in the US, Grant and Garland (2006) implied that actually 20-30% of CRC cases could be avoided by sufficient exposure to sunlight.A recent meta-analysis of 18 cohort and case-control studies showed that an elevation of serum 25-D 3 concentration to levels $33 ng/ml led to a 50% lower incidence of CRC (Gorham et al. 2005). Cumulative epidemiological evidence suggests that there is a direct correlation between reduced CRC incidence and sunlight exposure, nutritional vitamin D intake, and high serum levels of 25-D 3 (Giovannucci et al. 2006).Vitamin D metabolism is a strictly regulated, multistep process, beginning with the formation of previtamin D 3 in the skin, mediated by ultraviolet radiation, or with absorption of vitamin D from dietary sources (Henry 1997;Sawada et al. 2000;Cheng et al. 2003). Vitamin D is hydroxylated by CYP27A1 to 25-hydroxyvitamin D 3 in the liver. The last step of the activation is accomplished by the 25-hydroxyvitamin D 3 1a hydroxylase (CYP27B1) in the kidney. The most active metabolite of vitamin D 3, 1a,25-dyhydroxyvitamin D 3 (1,25-D 3 , also known as calcitriol), has a crucial Correspondence to: Enikö Kállay,

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