Absence of metallothionein 3 expression in breast cancer is a rare but favorable marker that is under epigenetic control

Cadmium (Cd²⁺), a known carcinogen, mimics the effects of estrogen in the uterus and mammary gland suggesting its possible involvement in the development and progression of breast cancer. This lab showed through analysis of a small set of archival human diagnostic specimens that the third isoform of the classic Cd²⁺ binding protein metallothionein (MT-3) is not expressed in normal breast tissue, but is expressed in some breast cancers and that expression tends to correlate with a poor disease outcome. The goals of this study were to verify that overexpression of MT-3 in a large set of archival human diagnostic specimens tends to correlate with poor disease outcome and define the mechanism of MT-3 gene regulation in the normal breast epithelial cell. The results showed that MT-3 was expressed in approximately 90% of all breast cancers and was absent in normal breast epithelium. The lack of MT-3 staining in some cancers correlated with a favorable patient outcome. High frequency of MT-3 staining was also found for in situ breast cancer suggesting that MT-3 might be an early biomarker for breast cancer. The study also demonstrated that the MCF-10A cell line, an immortalized, non-tumorigenic model of human breast epithelial cells, displayed no basal expression of MT-3, nor was it induced by Cd²⁺. Treatment of the MCF-10A cells with the demethylation agent, 5-aza-2′-deoxycytidine, or the histone deacetylase inhibitor, MS-275, restored MT-3 mRNA expression. It was also shown that the MT-3 metal regulatory elements are potentially active binders of protein factors following treatment with these inhibitors suggesting that MT-3 expression may be subject to epigenetic regulation.     

Effects of benzo(a)pyrene on blood components,tumor markers,and oxidative status in mice

This study was carried out to investigate the effect of long-term exposure to benzo(a)pyrene (B(a)P) in mice. Hemogram, tumor markers, oxidative status, and B(a)P residues in liver tissue were evaluated. Sixty albino Swiss mice were randomly distributed equally into three groups; the control was given 0.1?mL corn oil once a week for 8 weeks. The other two groups were given 20 and 40?mg B(a)P per kg body weight once a week orally for the same period. B(a)P-treated mice suffered from depression and ascites, and macrocytic normochromic anemia was recorded at the 16th and 30th week. There was marked leukocytosis with lymphocytosis at the early stage of the experiment, followed by leukopenia, lymphopenia, and neutropenia at the end of the experiment. Monocytes and arginase activity were elevated throughout the experiment. Alpha feto-protein was detected only in the experimental groups in the 30th week of the experiment. A marked increase in lipid peroxides associated with a decrease in reduced glutathione and glutathione-S-transferase (GST) activity was observed in liver homogenate of the B(a)P-exposed animals. Residues of B(a)P were detected in liver tissue with a concentration parallel to the B(a)P dose level. In conclusion, B(a)P caused abnormal changes in the hemogram, evidence of tumor formation through B(a)P-induced oxidative stress, and it was accumulated in the liver tissue of mice.     

Indoor and outdoor air pollution and lung cancer in New Hampshire and Vermont

Indoor and outdoor air pollution is known to contribute to increased lung cancer incidence. This study is the first to address the contribution of home heating fuel and geographical course particulate matter (PM₁₀) concentrations to lung cancer rates in New Hampshire, USA. First, Pearson correlation analysis and geographically weighted regression were used to investigate spatial relationships between outdoor PM₁₀ and lung cancer rates. While the aforementioned analyses did not indicate a significant contribution of PM₁₀ to lung cancer in the state, there was a trend towards a significant association in the northern and southwestern regions of the state. Second, case-control data were used to estimate the contributions of indoor pollution and secondhand smoke to the risk of lung cancer with adjustment for confounders. Increased risk was found among those who used wood or coal to heat their homes for more than 10 winters before the age of 18, with a significant increase in risk per winter. Resulting data suggest that further investigation of the relationship between heating-related air pollution levels and lung cancer risk is needed.     

Spore inhibition-based enzyme substrate assay for monitoring of aflatoxin M1 in milk

A spore germination-based concept and its transformation into a field level prototype for monitoring aflatoxin M₁ (AFM₁) in milk was developed. Initially, 15 strains of Bacillus spp. procured from different culture collection were screened for AFM₁ sensitivity using spot assay and marker strain showing inhibition at 0.5 ppb was selected based upon maximum zone of inhibition. The selected strain B. megaterium 2949 was further screened for different enzymes activities and subsequently its spores were produced to an extent of 73.13% ± 3.197% in newly developed sporulation medium containing beef extract (0.0075% ± 0.0004%), yeast extract (0.015% ± 0.001%), peptone (0.0375% ± 0.0016%), and sodium chloride (0.0375% ± 0.0018%). A spore germination-based concept/ assay was optimized by immobilizing spores in eppendorf with pretreated milk (80°C/15 min) containing germinant and chromogenic substrate followed by incubation at 37°C. The appearance of sky blue color within real time of 45 min indicated spores germination and release of specific marker enzyme such as acetyl esterase and its specific action on chromogenic substrate which demonstrates absence of AFM₁ in milk. However, if there was no color change, presence of AFM₁ at 0.5 ppb MRL was denoted by Codex. The developed concept on AFM₁ detection was validated and a correlation of 0.97 was established with AOAC approved Charm 6602 and ELISA at Codex MRL with minimal false positive and negative results. The cost effective test has potential application in dairy farms, manufacturing, and R&D units for routine monitoring of AFM₁ in milk.     

Polycyclic aromatic hydrocarbons in medicinal plants from Syria

The levels of 16 US Environmental Protection Agency polycyclic aromatic hydrocarbons (EPA PAHs) in 10 medicinal plants in different used parts of plant (leaves and flowers) have been determined. The analytical method consists of sample preparation by ultrasonic extraction with dichloromethane followed by silica gel clean-up. Subsequently, the analysis was carried out by reversed-phase high-performance liquid chromatography (HPLC) coupled to both ultraviolet and fluorescence detections in series to insure the detection of all 16 EPA PAHs. It was observed that the sum of the 16 PAHs (ΣPAHs) in the investigated medicinal plants ranged from 47 to 890 μg kg^–1 where the highest ΣPAHs was found in Sage plant sample. Light PAHs were dominants in all studied medicinal plants. The sum of eight genotoxic PAHs (ΣPAH8) have shown a better indicator of the degree of contamination with carcinogenic PAHs compared to benzo[a]pyrene in these products.     

Cadmium accumulation by green algae Cladophora glomerata (L.) Kutz. (Chlorophyta) in presence of Nile tilapia Oreochromis niloticus (L.)

Accumulation of metals by aquatic organisms is mostly affected by other biological components in environments. In this study, cadmium (Cd) accumulation in green algae, Cladophora glomerata (L.) Kutz., exposed to 0.1 and 1.0 mg L^?1 of Cd for 15 and 30 days was examined in laboratory conditions in the presence of Nile tilapia Oreochromis niloticus (L.). The green algae C. glomerata accumulated Cd concentrations as 690 ± 70 and 3430 ± 470 mg kg^?1 on day 15, and 1130 ± 180 and 6830 ± 1540 mg kg^?1 on day 30. There were significant increases (p < 0.05) in metal accumulation by green algae as the exposure time and metal concentration increased. The results also indicated that the presence of Nile tilapia in the medium led to a significant Cd accumulation in the green algae compared to control (p < 0.05).     

Mercury pollution in the Sonbhadra district of Uttar Pradesh,India, and its health impacts

The Sonbhadra district in the Singrauli area of Uttar Pradesh, India, has many coal mines and thermal power plants and is a critically polluted area. Many residents of this area reported adverse health conditions which may be linked to metal pollution, especially of mercury investigated here.

In May 2012, samples of water (23), soil (7), blood, hair, and nails from persons showing adverse health conditions selected at random were collected and analyzed for total mercury by atomic absorption spectrometry.

Twenty percent drinking water samples contained mercury from 3 to 26 μg L^?1 (3–26 times the permissible limit). Soil samples had 0.5–10.1 mg kg^?1 Hg.

The average concentrations of mercury in human blood, hair, and nails were found to be 34 μg L^?1, 7.4 mg kg^?1, and 0.8 mg kg^?1, respectively. Mercury concentrations in the blood of these persons were 45 and 28 μg L^?1 on average in the case of men and women. This is much higher than the safe level of 5.8 μg L^?1 set by the United States Environmental Protection Agency (USEPA).

It was concluded that all residents of Sonbhadra sampled could be suffering from mercury toxicity as the area is polluted by Hg released from the coal-fired thermal power plants.     

Carbofuran-induced effects on acetylcholinesterase (AChE) in erythrocytes and liver of Cyprinus carpio

A study was conducted to determine the effects of long-term exposure to carbofuran on erythrocyte and liver acetylcholinesterase (AChE) activity in Cyprinus carpio, and assess which tissue was more sensitive to pesticide exposure examining this enzyme. Fish were allowed to accilimatize in toxicant-free water for 24 days after 60-day exposure. AChE activity was determined with a spectrophotometer using acetylthiocholine iodide as a substrate in erythrocytes and liver. Enzymic activity of erythrocytes and liver decreased over time. A higher degree of enzyme inhibition was observed in erythrocyte compared to liver. The degree of enzyme inhibition was positively correlated with exposure time. When exposed fish were transferred to clean water, recovery was greater in erythrocytes than liver. Erythrocyte AChE activity recovered after 18 days, while it required 21 days in liver. The findings of this study indicate that erythrocyte AChE is more sensitive to carbofuran than liver. The greater sensitivity of erythrocyte AChE suggests that it may be more useful as a biomarker for monitoring status of pollution in freshwater bodies.     

Transport of metanil yellow in the rat plasma and interaction of its metabolite,p‐aminodiphenylamine with serum proteins

Binding affinity of metanil yellow and its breakdown product p‐aminodiphenylamine to serum proteins has been studied employing chromatographic separation on Sephadex G‐200 and by paper and polyacrylamide gel electrophoresis. Metanil yellow has more affinity towards albumin than to globulins. The complexing is presumably through electrostatic forces. p‐Aminodiphenylamine on the other hand, preferably binds to globulin fractions of serum protein. However, a stable binding with BSA alone was also observed. The binding was quite stable and was accompanied by a shift in absorbance from 430 nm to 500 nm. Aspartic acid moiety of protein was found to be one of the units involved in the binding of p‐ADPA to proteins.