Selective Association of Peroxiredoxin 1 with Genomic DNA and COX-2 Upstream Promoter Elements in Estrogen Receptor Negative Breast Cancer Cells

Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Manitoba R3E0V9, Canada.
Molecular biology of the cell (Impact Factor: 4.47). 09/2010; 21(17):2987-95. DOI: 10.1091/mbc.E10-02-0160
Source: PubMed

ABSTRACT In a search for proteins differentially cross-linked to DNA by cisplatin or formaldehyde in normal breast epithelial and breast cancer cell lines, we identified peroxiredoxin 1 (PRDX1) as a protein preferentially cross-linked to DNA in estrogen receptor negative (ER-) MDA-MB-231 but not in estrogen receptor positive (ER+) MCF7 breast cancer cells. Indirect immunofluorescence microscopic analyses showed that PRDX1 was located in the cytoplasm and nucleus of normal and breast cancer cells, with nuclear PRDX1 associated with promyelocytic leukemia protein bodies. We demonstrated that PRDX1 association with the transcription factor nuclear factor-kappaB (NF-kappaB) in MDA-MB-231 but not in MCF7 cells contributed to PRDX1-selective recruitment to MDA-MB-231 genomic DNA. Furthermore, PRDX1 was associated with the cyclooxygenase (COX)-2 upstream promoter region at sites occupied by NF-kappaB in ER- but not in ER+ breast cancer cells. PRDX1 knockdown attenuated COX-2 expression by reducing NF-kappaB occupancy at its upstream promoter element in MDA-MB-231 but not in MCF7 cells. A phosphorylated form of PRDX1 was only present in ER- breast cancer cells. Because PRDX1 phosphorylation is known to inhibit its peroxidase activity and to promote PRDX1 oligomerization, we propose that PRDX1 acts as a chaperone to enhance the transactivation potential of NF-kappaB in ER- breast cancer cells.

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Available from: James Davie, Sep 26, 2015
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    • "In lung cancer cells, hypoxia/reoxygenation can increase Prx1 expression by activating nuclear factor erythroid 2–related factor 2 (Nrf2), an important transcription factor involved in oxidant stress [26]. The loss of Prx1 expression can enhance the sensitivity to oxidants and therefore, increase ROS production and oxidative DNA damage [27]. In the present study, the mRNA and protein expression of Prx1 was up-regulated in SCC15 cells by either hypoxia (4 h, 12 h) alone or followed by reoxygenation (2 h). "
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    ABSTRACT: Overexpression of peroxiredoxin 1 (Prx1) has been observed in numerous cancers including oral squamous cell carcinoma (OSCC). The precise molecular mechanism of up-regulation of Prx1 in carcinogenesis, however, is still poorly understood. The objective of this study is to investigate the relationship between Prx1 and hypoxia, and potential mechanism(s) of Prx1 in OSCC cell line SCC15 and xenograft model. We treated wild-type and Prx1 knockdown SCC15 cells with transient hypoxia followed by reoxygenation. We detected the condition of hypoxia, production of reactive oxygen species (ROS), and expression and/or activity of Prx1, heme oxygenase 1 (HO-1) and nuclear factor-kappa B (NF-κB). We found that hypoxia induces ROS accumulation, up-regulates Prx1, increases NF-κB translocation and DNA binding activity, and down-regulates HO-1 in vitro. In Prx1 knockdown cells, the expression level of HO-1 was increased, while NFκB translocation and DNA binding activity were decreased after hypoxia or hypoxia/reoxygenation treatment. Moreover, we mimicked the dynamic oxygenation tumor microenvironment in xenograft model and assessed the above indices in tumors with the maximal diameter of 2 mm, 5 mm, 10 mm or 15 mm, respectively. Our data showed that tumor hypoxic condition and expression of Prx1 are significantly associated with tumor growth. The expression of HO-1 and NF-κB, and NF-κB DNA binding activity were significantly elevated in 15 mm tumors, and the level of 8-hydroxydeoxyguanosine was increased in 10 mm and 15 mm tumors, compared to those in size of 2 mm. The results from this study provide experimental evidence that overexpression of Prx1 is associated with hypoxia, and Prx1/NF-κB/HO-1 signaling pathway may be involved in oral carcinogenesis.
    PLoS ONE 08/2014; 9(8):e105994. DOI:10.1371/journal.pone.0105994 · 3.23 Impact Factor
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    • "Cytoplasmic Prx1 regulates H2O2-dependent NF-κB activation and nuclear translocation, and nuclear Prx1 regulates NF-κB/DNA binding through elimination of H2O2 as a p50 subunit oxidant [38]. Prx1 enhances p65-mediated cyclooxygenase (COX)-2 gene expression in estrogen receptor (ER) deficient human breast cancer cells (MDA-MB-231), and knockdown of Prx-I can attenuate COX-2 expression by reducing the occupancy of NF-κB at its upstream promoter element, indicating that Prx-I acts as a chaperone to enhance the transactivation potential of NF-kappaB in ER-deficient-breast cancer cells [39]. Actually, in the present study, knockdown of Prx-I reduced protein expressions of phospho-NF-κB p50 and p65, and thus it suppressed growth, promoted apoptosis and regulated the cell cycle of bladder cancer cells by inhibiting the NF-κB pathway, which conformed to the IPA network (Figure 2C). "
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    ABSTRACT: In order to understand the molecular mechanisms of Bifidobacterium infantis thymidine kinase/nucleoside analogue ganciclovir (BI-TK/GCV) treatment system which was proven to exhibit sustainable anti-tumor growth activity and induce apoptosis in bladder cancer, a proteomic approach of isobaric tags for relative and absolute quantification (iTRAQ), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used. 192 down-regulated and 210 up-regulated proteins were identified after treatment with BI-TK/GCV system in Sprague-Dawley (SD) rats. Western blot analysis and immunohistochemistry analysis confirmed that Peroxiredoxin-I (Prx-I) was significantly down-regulated in bladder cancer after treatment. Prx-I silencing by transfection of Prx-I shRNA significantly suppressed growth, promoted apoptosis and regulated the cell cycle in T24 cells and reduced the phospho-NF-κB p50 and p65 protein expression which revealed the links between Prx-I and NF-κB pathway implied by Ingenuity pathway analysis (IPA). These findings yield new insights into the therapy of bladder cancer, revealing Prx-I as a new therapeutic target and indicating BI-TK/GCV system as a prospective therapy by down-regulation of Prx-I through NF-κB signaling pathway.
    PLoS ONE 06/2014; 9(6):e98764. DOI:10.1371/journal.pone.0098764 · 3.23 Impact Factor
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    ABSTRACT: Malaria parasites are subjected to high levels of oxidative stress during their development inside erythrocytes and the ability of the parasite to defend itself against this assault is critical to its survival. Therefore, Plasmodium possesses an effective antioxidant defense system that could potentially be used as a target for the development of inhibitor-based therapy. We have identified an unusual peroxiredoxin protein that localizes to the nucleus of Plasmodium falciparum and have renamed it PfnPrx (PF10_0268, earlier called MCP1). Our work reveals that PfnPrx has a broad specificity of substrate being able to utilize thioredoxin and glutaredoxin as reductants and having the ability to reduce simple and complex peroxides. Intriguingly, chromatin immunoprecipitation followed by deep sequencing reveals that the enzyme associates with chromatin in a genome-wide manner with a slight enrichment in coding regions. Our results represent the first description of a dedicated chromatin-associated peroxiredoxin and potentially represent an ingenious way by which the parasite can survive the highly oxidative environment within its human host.
    Journal of Biological Chemistry 03/2011; 286(13):11746-55. DOI:10.1074/jbc.M110.198499 · 4.57 Impact Factor
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