Stimulation of alkaline phosphatase activity in Ishikawa cells induced by various phytoestrogens and synthetic estrogens

Wober, Jannette; Weisswange, Ina; Vollmer, Günter

doi:10.1016/s0960-0760(02)00252-2

Cited by 43 publications

(37 citation statements)

References 31 publications

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“…Therefore, it is reasonable to suggest that BPA, similarly to E2, binds to ERa and produces changes in these rapid signals. Few data address the ability of BPA to mediate nongenomic estrogenic actions (see [25][26][27][28][29][30][31] and, as far we know, no information focuses on the involvement of these pathways in the proliferative effect of BPA.…”

Section: Introductionmentioning

confidence: 99%

Expression of Concern: Laccase treatment impairs bisphenol A‐induced cancer cell proliferation affecting estrogen receptor α‐dependent rapid signals

et al. 2008

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SummaryA wide variety of environmental contaminants exert estrogenic actions in wildlife, laboratory animals, and in human beings through binding to nuclear estrogen receptors (ERs). Here, the mechanism(s) of bisphenol A (BPA) to induce cell proliferation and the occurrence of its bioremediation by treatment with laccase are reported. BPA, highly present in natural world and considered as a model of environmental estrogen action complexity, promotes human cancer cell proliferation via ERa-dependent signal transduction pathways. Similar to 17b-estradiol, BPA increases the phosphorylation of both extracellular regulated kinase and AKT. Specific inhibitors of these kinase completely block the BPA effect on cancer cell proliferation. Notably, high BPA concentrations (i.e., 0.1 and 1 mM) are cytotoxic even in ERa-devoid cancer cells, indicating that an ERa-independent mechanism participates to BPA-induced cytotoxicity. On the other hand, BPA oxidation by laccase impairs the binding of this environmental estrogen to ERa loosing at all ERa-dependent effect on cancer cell proliferation. Moreover, the laccase-catalyzed oxidation of BPA reduces the BPA cytotoxic effect. Thus, laccase appears to impair BPA action(s), representing an invaluable bioremediation enzyme.2008 IUBMB IUBMB Life, 60(12): 843-852, 2008

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Section: Introductionmentioning

confidence: 99%

Expression of Concern: Laccase treatment impairs bisphenol A‐induced cancer cell proliferation affecting estrogen receptor α‐dependent rapid signals

et al. 2008

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“…Genistein is listed in the literature as an inhibitor of protein tyrosine kinase [15], and IBMX as a non-selective phosphodiesterase inhibitor [7], However, these two compounds have also been reported to affect ALP activity [22,23]. Following this thought, the effects of both genistein and IBMX on the present assay of ALP activity were investigated.…”

Section: Discussionmentioning

confidence: 99%

Contributions of phosphorylation to regulation of OCTN2 uptake of carnitine are minimal in BeWo cells

Rytting

Audus

2008

Biochemical Pharmacology

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Physiological functions of organic cation transporters (OCTs) in the placenta include transporting essential nutrients from the maternal to fetal circulations. OCTN2 transports carnitine with high affinity, and the transport of several drugs has also been shown to be mediated by this transporter. In this work, the role of phosphorylation and dephosphorylation mechanisms in regulating OCTN2 was investigated by observing the effects of various activators and inhibitors of kinases and phosphatases on the uptake of carnitine in BeWo cells, a human choriocarcinoma trophoblast cell line frequently used as an in vitro model of the rate-limiting barrier for maternal-fetal exchange. Preincubation with genistein resulted in significant increases in both alkaline phosphatase (ALP) activity and carnitine uptake. Levamisole, an ALP inhibitor, caused a more substantial decrease in carnitine uptake than expected from its corresponding decrease in ALP activity. It was determined that levamisole competitively inhibits carnitine uptake, with a K i value of 1.01 ± 0.05 mM, and this effect has a greater role in decreasing carnitine uptake than any indirect effects of ALP inhibition upon OCTN2 function. Progesterone also competitively inhibited carnitine uptake (K i = 48.6 ± 5.0 μM), but had no effect on ALP activity in BeWo cells.

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“…Thus, it is not unexpected that dietary phytoestrogens could play a role in the pathophysiology of an estrogen-dependent (37) condition such as endometriosis. At the level of the endometrium, phytoestrogens have been shown to potentially act as agonists in animal models (38)(39)(40)(41). However, human studies have suggested that the dosage and length of supplementation may be important to consider because isoflavone treatment for a period of 5 y was associated with endometrial hyperplasia (19), whereas shortterm treatments were not (19,32,33).…”

Section: Discussionmentioning

confidence: 99%

Urinary Phytoestrogen Concentrations Are Not Associated with Incident Endometriosis in Premenopausal Women

Weck

Louis

2017

The Journal of Nutrition

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Stimulation of alkaline phosphatase activity in Ishikawa cells induced by various phytoestrogens and synthetic estrogens

Cited by 43 publications

References 31 publications

Expression of Concern: Laccase treatment impairs bisphenol A‐induced cancer cell proliferation affecting estrogen receptor α‐dependent rapid signals

Expression of Concern: Laccase treatment impairs bisphenol A‐induced cancer cell proliferation affecting estrogen receptor α‐dependent rapid signals

Contributions of phosphorylation to regulation of OCTN2 uptake of carnitine are minimal in BeWo cells

Urinary Phytoestrogen Concentrations Are Not Associated with Incident Endometriosis in Premenopausal Women

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