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Jabareen A, Abu-Jaafar A, Abou-Kandil A, Huleihel M. Effect of TPA and HTLV-1 Tax on BRCA1 and ERE controlled genes expression. Cell Cycle 2017; 16:1336-1344. [PMID: 28594273 DOI: 10.1080/15384101.2017.1327491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Interference with the expression and/or functions of the multifunctional tumor suppressor BRCA1 leads to a high risk of breast and ovarian cancers. BRCA1 expression is usually activated by the estrogen (E2) liganded ERα receptor. Activated ERα is considered as a potent transcription factor which activates various genes expression by 2 pathways. A classical pathway, ERα binds directly to E2-responsive elements (EREs) in the promoters of the responsive genes and a non-classical pathway where ERα indirectly binds with the appropriate gene promoter. In our previous study, HTLV-1Tax was found to strongly inhibit ERα induced BRCA1 expression while stimulating ERα induced ERE dependent genes. TPA is a strong PKC activator which found to induce the expression of HTLV-1. Here we examined the effect of TPA on the expression of BRCA1 and genes controlled by ERE region in MCF-7 cells and on Tax activity on these genes. Our results showed strong stimulatory effect of TPA on both BRCA1 and ERE expression without treatment with E2. Tax did not show any significant effect on these TPA activities. It seems that TPA activation of BRCA1 and ERE expression is dependent on PKC activity but not through the NFκB pathway. However, 53BP1 may be involved in this TPA activity because its overexpression significantly reduced the TPA stimulatory effect on BRCA1 and ERE expression. Additionally, our Chip assay results probably exclude possible involvement of ERα pathway in this TPA activity because TPA did not interfere with the binding of ERα to both BRCA1 promoter and ERE region.
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Affiliation(s)
- Azhar Jabareen
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Aya Abu-Jaafar
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Ammar Abou-Kandil
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
| | - Mahmoud Huleihel
- a Shraga Segal Department of Microbiology and Immunology , Faculty of Health Sciences, Ben Gurion University of the Negev , Beer Sheva , Israel
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Tarnow P, Hutzler C, Grabiger S, Schön K, Tralau T, Luch A. Estrogenic Activity of Mineral Oil Aromatic Hydrocarbons Used in Printing Inks. PLoS One 2016; 11:e0147239. [PMID: 26771904 PMCID: PMC4714758 DOI: 10.1371/journal.pone.0147239] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/30/2015] [Indexed: 11/19/2022] Open
Abstract
The majority of printing inks are based on mineral oils (MOs) which contain complex mixtures of saturated and aromatic hydrocarbons. Consumer exposure to these oils occurs either through direct skin contacts or, more frequently, as a result of MO migration into the contents of food packaging that was made from recycled newspaper. Despite this ubiquitous and frequent exposure little is known about the potential toxicological effects, particularly with regard to the aromatic MO fractions. From a toxicological point of view the huge amount of alkylated and unsubstituted compounds therein is reason for concern as they can harbor genotoxicants as well as potential endocrine disruptors. The aim of this study was to assess both the genotoxic and estrogenic potential of MOs used in printing inks. Mineral oils with various aromatic hydrocarbon contents were tested using a battery of in vitro assays selected to address various endpoints such as estrogen-dependent cell proliferation, activation of estrogen receptor α or transcriptional induction of estrogenic target genes. In addition, the comet assay has been applied to test for genotoxicity. Out of 15 MOs tested, 10 were found to potentially act as xenoestrogens. For most of the oils the effects were clearly triggered by constituents of the aromatic hydrocarbon fraction. From 5 oils tested in the comet assay, 2 showed slight genotoxicity. Altogether it appears that MOs used in printing inks are potential endocrine disruptors and should thus be assessed carefully to what extent they might contribute to the total estrogenic burden in humans.
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Affiliation(s)
- Patrick Tarnow
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany, Max-Dohrn-Strasse 8–10, 10598, Berlin, Germany
- * E-mail:
| | - Christoph Hutzler
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany, Max-Dohrn-Strasse 8–10, 10598, Berlin, Germany
| | - Stefan Grabiger
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany, Max-Dohrn-Strasse 8–10, 10598, Berlin, Germany
| | - Karsten Schön
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany, Max-Dohrn-Strasse 8–10, 10598, Berlin, Germany
| | - Tewes Tralau
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany, Max-Dohrn-Strasse 8–10, 10598, Berlin, Germany
| | - Andreas Luch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany, Max-Dohrn-Strasse 8–10, 10598, Berlin, Germany
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