The development of prostate cancer and its progression to a hormone-refractory state is highly dependent on androgen receptor (AR) expression. Recent studies have shown that the selenium-based compound methylseleninic acid (MSeA) can disrupt AR signaling in prostate cancer cells. We have found that selenite can inhibit AR expression and activity in LAPC-4 and LNCaP prostate cancer cells as well...

The relative effectiveness of either sodium selenite or selenomethionine in the inhibition of mammary carcinogenesis was studied in virgin female Sprague-Dawley rats. In one experiment, rats were given 50 mg of 1-methyl-1-nitrosourea per kg of body weight s.c. at 50 days of age. Beginning 7 days post-1 -methyl1-nitrosourea, they were assigned to a basal diet containing 0.1 ppm of selenium or ba...

The present studies demonstrate that the ability of supplemental selenite to alter the in vitro growth of canine mammary tumor cell line 13 was dependent on the quantity and duration of selenium exposure and on the culture density. Exposure to 3.2 microM selenite did not significantly alter growth but led to an increase in intracellular glutathione (GSH). The severity of growth inhibition betwe...

Selenium is an essential trace element in mammals, but is toxic at high levels. It is best known for its cancer prevention activity, but cancer cells are more sensitive to selenite toxicity than normal cells. Since selenite treatment leads to oxidative stress, and the Trx (thioredoxin) system is a major antioxidative system, we examined the interplay between TR1 (Trx reductase 1) and Trx1 defic...

New polymeric membrane (PME), modified carbon paste (MCPE), and coated wire (CWE) selenite ion-selective electrodes based on 5,10,15,20-tetrakis-(4-methoxyphenyl)-21H,23H-porphyrin-Co(II) (CoTMeOPP) are reported. The best composition was the electrode containing 2% CoTMeOPP as the active material and 49% TCP as plasticizer. The electrodes reveal a Nernstian behavior over a concentration range o...

the present investigation was performed to determine the effect of long-term administration of sodium selenite on the biochemical indices and concentration of thyroid hormones in calves. sodium selenite solution was drenched at 0.1 and 0.25 mg per kg body weight for 12 weeks. higher dose produced characteristic symptoms of selenosis whereas mild symptoms were observed with lower dose. the toxic...

The level of selenium-resistant bacteria in water, algal mats, and sediment from Kesterson reservoir, Calif., a site with known selenium pollution, was compared with that in nearby Volta reservoir, a site with low selenium levels. A high percentage (greater than 50%) of all isolates from the Kesterson samples were resistant to 10 mM selenite. In contrast, only a small percentage of the Volta is...

In the present study, we investigated the adsorption of selenite [Se(IV)] onto hematite, which usually exists in soils and rocks, focusing on the effect of humic acid. The selenite adsorption onto hematite varied with the contact time, finally reaching an equilibrium state in 5 hours. The result was in good agreement with the Parabolic diffusion equation (R 2 = 0.97). The adsorption with differ...

Rice (Oryza sativa) as a staple food, provides a major source of dietary selenium (Se) for humans, which essentially requires Se, however, the molecular mechanism for Se uptake is still poorly understood. Herein, we show evidence that the uptake of selenite, a main bioavailable form of Se in paddy soils, is mediated by a silicon (Si) influx transporter Lsi1 (OsNIP2;1) in rice. Defect of OsNIP2;...

To study the effect of low molecular weight antioxidants on respiration process, content auxins and abscisic acid, 15-day-old potato (Solanum tuberosum) tubers grown under laboratory conditions were sprayed with 5.8 μM sodium selenite solution or 0.1 mM caffeic acid solution. Control runners treated water. Hypothermia (-2 °C) simulating freezing was created for 2 hours. 21-day-old analyzed. Und...