Long-term dietary cadmium intake and postmenopausal endometrial cancer incidence: a population-based prospective cohort study

Risk assessment of effects of cadmium on human health (IUPAC Technical Report)

Chemistry and Human Health, Division VII of the International Union on Pure and Applied Chemistry (IUPAC), provides guidance on risk assessment methodology and, as appropriate, assessment of risks to human health from chemicals of exceptional toxicity. The aim of this document is to describe dose-response relationships for the health effects of low-level exposure to cadmium, in particular, with an emphasis on causation. The term “cadmium” in this document includes all chemical species of cadmium, as well as those in cadmium compounds. Diet is the main source of cadmium exposure in the general population. Smokers and workers in cadmium industries have additional exposure. Adverse effects have been shown in populations with high industrial or environmental exposures. Epidemiological studies in general populations have also reported statistically significant associations with a number of adverse health effects at low exposures. Cadmium is recognized as a human carcinogen, a classification mainly based on occupational studies of lung cancer. Other cancers have been reported, but dose-response relationships cannot be defined. Cardiovascular disease has been associated with cadmium exposure in recent epidemiological studies, but more evidence is needed in order to establish causality. Adequate evidence of dose-response relationships is available for kidney effects. There is a relationship between cadmium exposure and kidney effects in terms of low molecular mass (LMM) proteinuria. Long-term cadmium exposures with urine cadmium of 2 nmol mmol−1 creatinine cause such effects in a susceptible part of the population. Higher exposures result in increases in the size of these effects. This assessment is supported by toxicokinetic and toxicodynamic (TKTD) modelling. Associations between urine cadmium lower than 2 nmol mmol−1 creatinine and LMM proteinuria are influenced by confounding by co-excretion of cadmium with protein. A number of epidemiological studies, including some on low exposures, have reported statistically significant associations between cadmium exposure and bone demineralization and fracture risk. Exposures leading to urine cadmium of 5 nmol mmol−1 creatinine and more increase the risk of bone effects. Similar associations at much lower urine cadmium levels have been reported. However, complexities in the cause and effect relationship mean that a no-effect level cannot be defined. LMM proteinuria was selected as the critical effect for cadmium, thus identifying the kidney cortex as the critical organ, although bone effects may occur at exposure levels similar to those giving rise to kidney effects. To avoid these effects, population exposures should not exceed that resulting in cadmium values in urine of more than 2 nmol mmol−1 creatinine. As cadmium is carcinogenic, a ‘safe’ exposure level cannot be defined. We therefore recommend that cadmium exposures be kept as low as possible. Because the safety margin for toxic effects in kidney and bone is small, or non-existent, in many populations around the world, there is a need to reduce cadmium pollution globally.

A highly selective and sensitive fluorescent chemosensor for distinguishing cadmium(ii) from zinc(ii) based on amide tautomerization

A naphthalimide-derived fluorescent sensor termed L2 was designed and synthesized.

State of the evidence 2017: an update on the connection between breast cancer and the environment

BACKGROUND

In this review, we examine the continually expanding and increasingly compelling data linking radiation and various chemicals in our environment to the current high incidence of breast cancer. Singly and in combination, these toxicants may have contributed significantly to the increasing rates of breast cancer observed over the past several decades. Exposures early in development from gestation through adolescence and early adulthood are particularly of concern as they re-shape the program of genetic, epigenetic and physiological processes in the developing mammary system, leading to an increased risk for developing breast cancer. In the 8 years since we last published a comprehensive review of the relevant literature, hundreds of new papers have appeared supporting this link, and in this update, the evidence on this topic is more extensive and of better quality than that previously available.

CONCLUSION

Increasing evidence from epidemiological studies, as well as a better understanding of mechanisms linking toxicants with development of breast cancer, all reinforce the conclusion that exposures to these substances - many of which are found in common, everyday products and byproducts - may lead to increased risk of developing breast cancer. Moving forward, attention to methodological limitations, especially in relevant epidemiological and animal models, will need to be addressed to allow clearer and more direct connections to be evaluated.

Cadmium exposure and endometrial cancer risk: A large midwestern U.S. population-based case-control study

Estrogen-mimicking chemicals, such as cadmium, may be associated with increased susceptibility to hormone-dependent cancers, though supporting data are sparse, particularly for endometrial cancer. The Health and Environmental Exposure Research (HEER) study worked with the Arkansas Central Cancer Registry, Iowa Cancer Registry and Missouri Cancer Registry to obtain names of women diagnosed with endometrial cancer who were willing to be contacted for participation in our case control study. Voter registration lists from Iowa and Missouri were used to randomly select similarly aged women as represented in the case population. Participants were interviewed by telephone to obtain information on known or suspected endometrial risk factors. Urine kits were sent to participants for home collection and returned for analysis. Our case-control study consisted of 631 incident cases of endometrial cancer diagnosed from January 2010 to October 2012 and 879 age-matched population-based controls, ages 18-81 years (mean age 65 years). We quantified cadmium amounts in urine and standardized these values through creatinine adjustment. Using data from all survey completers, we developed a multivariable model for endometrial cancer. Creatinine-adjusted cadmium concentration was added to this model. Odds ratio (OR) and 95% confidence intervals (CIs) for endometrial cancer were calculated. After multivariable adjustment, higher creatinine-adjusted cadmium exposure was associated with a statistically significant increase of endometrial cancer risk (OR: 1.22; 95% CI: 1.03-1.44). Our results provide evidence that cadmium may increase the risk of endometrial cancer, possibly through estrogenic effects.

MoS2-Nanosheet-Assisted Coordination of Metal Ions with Porphyrin for Rapid Detection and Removal of Cadmium Ions in Aqueous Media

Molybdenum disulfide (MoS₂) is a two-dimensional (2D) graphene-like material that is gaining great attention because of its potential application in various fields. Here, we reported a self-assembled nanocomposite consisted of MoS₂ nanosheets and 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrintetra(p-toluenesulfonate) (TMPyP), named MoS₂@TMPyP. This nanocomposite can be used as a sensing probe for low cost, rapid, selective detection of cadmium (Cd²⁺) ions. It is found that a new Soret band at 442 nm in UV-vis absorption spectra represented the coordination of Cd²⁺ ions into TMPyP of the MoS₂@TMPyP. The coordination rates between TMPyP and Cd²⁺ ions is greatly accelerated from 72 h to 20 min with the assistance of MoS₂, which is 200 times faster than in the absence of MoS₂. The limit of detection (LOD) of the Cd²⁺ is as low as 7.2 × 10^-8 mol/L. The binding behavior between the cationic TMPyP and MoS₂ nanosheets was corroborated by molecular dynamics simulation and various control experiments. The results demonstrated that electrostatic interaction was the main force for driving TMPyP enriching around the MoS₂ surface, resulting in an accelerated complexation of Cd²⁺ and TMPyP. Moreover, MoS₂@TMPyP nanocomposite can also be used for removing of Cd²⁺ in water. The removal efficiency (RF) of the MoS₂@TMPyP can reach to 91% for high concentrations of Cd²⁺. This work provides a new insight into detection and removal of Cd²⁺ ions in water.

Dietary cadmium exposure assessment among the Chinese population

Cadmium, a toxic heavy metal, is widely present in food. It has been reported that chronic cadmium exposure is associated with kidney disease, osteoporosis, cardiovascular disease and cancer. The aim of this study was to assess the dietary cadmium exposure and potential health risk in different age-sex groups of the Chinese population (children aged 4–11 years, young people aged 12–17 years and adults aged over 18 years), and in the southern and northern population using a semi-probabilistic method. Cadmium was detected in 228,687 food samples from 32 food categrories by graphite furnace atomic absorption spectrometry. The dietary cadmium exposures were estimated by combining the cadmium concentration data with food consumption data derived from the China National Nutrient and Health Survey 2002, and evaluated against the Provisional Tolerable Monthly Intake (PTMI) of 25 μg/kg BW/month established by the Joint FAO/WHO expert committee on food additives (JECFA). The mean dietary cadmium exposure of the general Chinese population (15.3 μg/kg BW/month) was below the PTMI. The high consumer exposures (95^th percentile, P95) for the general population and different sub-groups were higher than the PTMI. The dietary cadmium exposure of the southern population was apparently higher than that of the northern population. Rice was the most important contributor to cadmium exposure for Chinese people, especially those living in the southern areas of China. These findings indicated that the health risk from dietary cadmium exposure of the general Chinese people was low, but the health risk of cadmium exposure of certain sub-groups should be of concern.

Recombinant heat shock protein 27 (HSP27/HSPB1) protects against cadmium-induced oxidative stress and toxicity in human cervical cancer cells

Cadmium (Cd) is a carcinogen with several well-described toxicological effects in humans, but its molecular mechanisms are still not fully understood. Overexpression of heat shock protein 27 (HSP27/HSPB1)-a multifunctional protein chaperone-has been shown to protect cells from oxidative damage and apoptosis triggered by Cd exposure. The aims of this work were to investigate the potential use of extracellular recombinant HSP27 to prevent/counteract Cd-induced cellular toxicity and to evaluate if peroxynitrite was involved in the development of Cd-induced toxicity. Here, we report that the harmful effects of Cd correlated with changes in oxidative stress markers: upregulation of reactive oxygen species, reduction in nitric oxide (NO) bioavailability, increment in lipid peroxidation, peroxynitrite (PN), and protein nitration; intracellular HSP27 was reduced. Treatments with Cd (100 μM) for 24 h or with the peroxynitrite donor, SIN-1, decreased HSP27 levels (~50%), suggesting that PN formation is responsible for the reduction of HSP27. Pre-treatments of the cells either with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) (a pharmacological inhibitor of NO synthase) or with recombinant HSP27 (rHSP27) attenuated the disruption of the cellular metabolism induced by Cd, increasing in a 55 and 52%, respectively, the cell viability measured by CCK-8. Cd induced necrotic cell death pathways, although apoptosis was also activated; pre-treatment with L-NAME or rHSP27 mitigated cell death. Our findings show for the first time a direct relationship between Cd-induced toxicity and PN production and a role for rHSP27 as a potential therapeutic agent that may counteract Cd toxicity.

A morphological study of uterine alterations in mice due to exposure to cadmium

We investigated the morphologic and molecular effects of exposure to cadmium (Cd) for 30 and 60 days on the uteri of mice. We assessed uterine morphometric measurements, eosinophilia, mast cell numbers, endometrial apoptosis, proliferation and estrogen receptor alpha (ERα) immunoreactivity. We examined vaginal smears that reflected the hormonal alterations in the female reproductive tract. Because the female reproductive tract exhibits different morphology at each stage of the estrous cycle, we sacrificed all animals at estrus to make appropriate comparisons. Female BALB/c mice were exposed to 200 ppm Cd in their drinking water for either 30 or 60 days. Cd exposure caused significant decreases in endometrial thickness and number of glands in estrus phase uteri. The endometrial eosinophilia in the groups exposed to Cd also decreased compared to controls. Cd exposure increased the number of mast cells. Luminal and glandular epithelia were examined using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and by immunostaining proliferating cell nuclear antigen (PCNA) and estrogen receptor α (ERα). Compared to controls, the apoptotic index increased with time in both Cd exposed groups, while the proliferation index decreased. ERα immunoreactivity was decreased in both Cd exposed groups compared to controls; the decrease was most apparent in the 30 day Cd group. We found that 60 day Cd exposure increased apoptosis in the endometrium, which may affect the receptivity of the uterus for implantation.

Endocrine Disrupting Chemicals and Endometrial Cancer: An Overview of Recent Laboratory Evidence and Epidemiological Studies

Background: Although exposure to endocrine disruptor compounds (EDCs) has been suggested as a contributing factor to a range of women's health disorders including infertility, polycystic ovaries and the early onset of puberty, considerable challenges remain in attributing cause and effect on gynaecological cancer. Until recently, there were relatively few epidemiological studies examining the relationship between EDCs and endometrial cancer, however, in the last years the number of these studies has increased. Methods: A systematic MEDLINE (PubMed) search was performed and relevant articles published in the last 23 years (from 1992 to 2016) were selected. Results: Human studies and animal experiments are confirming a carcinogenic effect due to the EDC exposure and its carcinogenesis process result to be complex, multifactorial and long standing, thus, it is extremely difficult to obtain the epidemiological proof of a carcinogenic effect of EDCs for the high number of confusing factors. Conclusions: The carcinogenic effects of endocrine disruptors are plausible, although additional studies are needed to clarify their mechanisms and responsible entities. Neverthless, to reduce endocrine disruptors (ED) exposure is mandatory to implement necessary measures to limit exposure, particularly during those periods of life most vulnerable to the impact of oncogenic environmental causes, such as embryonic period and puberty.

Correlation of Cadmium and Magnesium in the Blood and Serum Samples of Smokers and Non-Smokers Chronic Leukemia Patients

It was studied that cancer-causing processes are related with the disproportions of essential and toxic elements in body tissues and fluid. The purpose of the current study was to evaluate the levels of magnesium (Mg) and cadmium (Cd) in serum and blood samples of smokers and nonsmokers who have chronic myeloid (CML) and lymphocytic (CLL) leukemia, age ranged 31-50 years. For comparative study, age-matched smokers and nonsmoker males were chosen as controls/referents. The levels of elements in patient were analyzed before any treatment by atomic absorption spectrophotometer, after microwave assisted acid digestion. The validation of the method was done by using certified reference materials of serum and blood samples. The resulted data indicated that the adult male smokers and nonsmokers have two- to fourfold higher levels of Cd in the blood and sera samples as compared to the referents (p < 0.01), whereas two- to threefold lower levels of Mg was found in blood and serum samples of both types of leukemia patients as related to referent values. The resulted data indicates significant negative correlation among Mg and Cd in leukemia patients and smoker referents. Further studies are needed to clarify the role of these elements in pathogenesis of chronic leukemia.

Arsenic, cadmium, lead and mercury levels in blood of Finnish adults and their relation to diet, lifestyle habits and sociodemographic variables

The Northern Finland Birth Cohort program (NFBC) is the epidemiological and longitudinal prospective general population research program, which was established to promote health and wellbeing of the population in northern Finland. The aim of present study, as a part of the NFBC program, was to analyze the blood levels of arsenic (B-As), cadmium (B-Cd), lead (B-Pb), total mercury (B-Hg) and selenium (B-Se); to compare these levels with threshold limits; to study sociodemographic factors; and to correlate these levels with calcium and haemoglobin. The study was comprised of 249 NFBC subjects, of which 123 were female and 126 were male (ages 31.1 ± 0.3 and 31.1 ± 0.4, respectively). All participants were asked to complete a questionnaire regarding diet and living habits. The geometric means (± SD) of B-As were 0.49 ± 2.80 μg/l and 0.44 ± 2.72 μg/l; B-Cd were 0.18 ± 4.02 μg/l and 0.12 ± 3.21 μg/l; B-Pb were 17.0 ± 1.8 μg/l and 9.06 ± 2.20 μg/l; B-Hg were 2.18 ± 2.02 μg/l and 1.85 ± 1.78 μg/l; and B-Se were 106.0 ± 1.3 and 94.3 ± 1.3 μg/l in males and females, respectively. Among the subjects in the present analysis, 23 % of males and 17.1 % of females had B-As levels above the ATSDR normal human levels of B-As in unexposed individuals (1.0 μg/l). The B-Pb geometric mean (12.44 μg/l) was approximately one eighth the CDC toxicological cut-off point of 100 μg/l. Twenty-one individuals (8.4 %) exceeded a B-Hg level of 5.8 μg/l. Fifty-eight females (47 %) had a B-Hg higher than 2.0 μg/l, the German Federal Environmental Agency cut-off point for women (18-69 years) who consume fish at least three times/month; therefore, their babies could be at risk of adverse effects during development.

Is Urinary Cadmium a Biomarker of Long-term Exposure in Humans? A Review

Cadmium is a naturally-occurring element, and humans are exposed from cigarettes, food, and industrial sources. Following exposure, cadmium accumulates in the kidney and is slowly released into the urine, usually proportionally to the levels found in the kidneys. Cadmium levels in a single spot urine sample have been considered indicative of long-term exposure to cadmium; however, such a potentially exceptional biomarker requires careful scrutiny. In this review, we report good to excellent temporal stability of urinary cadmium (intraclass correlation coefficient 0.66-0.81) regardless of spot urine or first morning void sampling. Factors such as changes in smoking habits and diseases characterized by increased excretion of proteins may produce short-term changes in urinary cadmium levels. We recommend that epidemiologists use this powerful biomarker in prospective studies stratified by smoking status, along with thoughtful consideration of additional factors that can influence renal physiology and cadmium excretion.

Carcinogenetic mechanisms of endocrine disruptors in female cancers (Review)

Endocrine disruptors (EDs) are pollutants that alter the endocrine system and are involved in carcinogenesis. EDs have multiple and complex levels of action. They can affect the synthesis, release and transport of natural hormones. In target tissues, EDs can reduce or increase the effects of natural hormones on their receptors and change signaling cascades. When ED exposure happens at critical periods of life, from embryo to puberty, they can act at doses considered safe for an adult. Furthermore, their epigenetic effects can also influence the cancer risk of future generations. The cancer mechanisms of known EDs are hereby reviewed, There are thousands of newly introduced substances whose potential endocrine-disrupting and cancer effects are completely unknown. Although there are still gaps in our knowledge, these data support the urgent need for health and environmental policies aimed at protecting the public and in particular, the developing fetus and women of reproductive age.

Whole Genome Pathway Analysis Identifies an Association of Cadmium Response Gene Loss with Copy Number Variation in Mutant p53 Bearing Uterine Endometrial Carcinomas

Background

Massive chromosomal aberrations are a signature of advanced cancer, although the factors promoting the pervasive incidence of these copy number alterations (CNAs) are poorly understood. Gatekeeper mutations, such as p53, contribute to aneuploidy, yet p53 mutant tumors do not always display CNAs. Uterine Corpus Endometrial Carcinoma (UCEC) offers a unique system to begin to evaluate why some cancers acquire high CNAs while others evolve another route to oncogenesis, since about half of p53 mutant UCEC tumors have a relatively flat CNA landscape and half have 20–90% of their genome altered in copy number.

Methods

We extracted copy number information from 68 UCEC genomes mutant in p53 by the GISTIC2 algorithm. GO term pathway analysis, via GOrilla, was used to identify suppressed pathways. Genes within these pathways were mapped for focal or wide distribution. Deletion hotspots were evaluated for temporal incidence.

Results

Multiple pathways contributed to the development of pervasive CNAs, including developmental, metabolic, immunological, cell adhesion and cadmium response pathways. Surprisingly, cadmium response pathway genes are predicted as the earliest loss events within these tumors: in particular, the metallothionein genes involved in heavy metal sequestration. Loss of cadmium response genes were associated with copy number changes and poorer prognosis, contrasting with 'copy number flat' tumors which instead exhibited substantive mutation.

Conclusion

Metallothioneins are lost early in the development of high CNA endometrial cancer, providing a potential mechanism and biological rationale for increased incidence of endometrial cancer with cadmium exposure. Developmental and metabolic pathways are altered later in tumor progression.

A new and highly selective turn-on fluorescent sensor with fast response time for the monitoring of cadmium ions in cosmetic, and health product samples

Cadmium (Cd) which is an extremely toxic could be found in many products like plastics, fossil fuel combustion, cosmetics, water resources, and wastewaters. It is capable of causing serious environmental and health problems such as lung, prostate, renal cancers and the other disorders. So, the development of a sensor to continually monitor cadmium is considerably demanding. Tetrakis(4-nitrophenyl)porphyrin, T(4-NO2-P)P, was synthesized and used as a new and highly selective fluorescent probe for monitoring cadmium ions in the "turn-on" mode. There was a linear relationship between fluorescence intensity and the concentration of Cd(II) in the range of 1.0×10(-6) to 1.0×10(-5)molL(-1) with a detection limit of 0.276μM. To examine the most important parameters involved and their interactions in the sensor optimization procedure, a four-factor central composite design (CCD) combined with response surface modeling (RSM) was implemented. The practical applicability of the developed sensor was investigated using real cosmetic, and personal care samples.

Soil amendment affects Cd uptake by wheat - are we underestimating the risks from chloride inputs?

Many parts of the world are investigating the efficacy of recycling nutrient resources to agriculture from different industry and domestic sectors as part of a more circular economy. The complex nature of recycled products as soil amendments coupled to the large diversity of soil types and their inherent properties make it difficult to optimize the benefits and minimize the risks from potentially toxic elements often present in recycled materials. Here we investigated how wheat grain cadmium (Cd) concentration was affected by soil amendments, namely human urine and biogas digestate compared to traditional farm manures and mineral fertilizers. We show that Cl(-) inadvertently added to soils with e.g. urine or biogas digestate strongly increased crop Cd concentrations, largely by mobilizing inherent soil Cd. This resulted in wheat grain Cd levels that could result in exceeding recommended WHO limits for dietary intake. This was evident even in soils with low inherent Cd content and when Cd inputs were low. The future of a circular economy that helps to underpin global food security needs to ensure that the effects of applying complex materials to different types of agricultural land are fully understood and do not jeopardize food safety.

Urinary Cadmium and Risk of Invasive Breast Cancer in the Women's Health Initiative

Cadmium is a widespread heavy metal pollutant that may act as an exogenous estrogenic hormone. Environmental cadmium exposure has been associated with risk of breast cancer in retrospective studies. We prospectively assessed the relationship between cadmium exposure, evaluated by creatinine-normalized urinary cadmium concentration, and invasive breast cancer among 12,701 postmenopausal women aged ≥50 years in a Women's Health Initiative study of bone mineral density. After a median of 13.2 years of follow-up (1993-2010), 508 cases of invasive breast cancer and 1,050 comparison women were identified for a case-cohort analysis. Multivariable Cox regression was used to calculate hazard ratios and 95% confidence intervals. Risk of breast cancer was not associated with urinary cadmium parameterized either in quartiles (comparing highest quartile with lowest, hazard ratio = 0.80, 95% confidence interval: 0.56, 1.14; P for trend = 0.20) or as a log-transformed continuous variable (per 2-fold higher urinary cadmium concentration, hazard ratio = 0.94, 95% confidence interval: 0.86, 1.03). We did not observe an association between urinary cadmium and breast cancer risk in any subgroup examined, including never smokers and women with body mass index (weight (kg)/height (m)(2)) less than 25. Results were consistent in both estrogen receptor-positive and estrogen receptor-negative tumors. Our results do not support the hypothesis that environmental cadmium exposure is associated with risk of postmenopausal breast cancer.

Urinary cadmium and estimated dietary cadmium in the Women's Health Initiative

Cadmium, a heavy metal dispersed in the environment as a result of industrial and agricultural applications, has been implicated in several human diseases including renal disease, cancers, and compromised bone health. In the general population, the predominant sources of cadmium exposure are tobacco and diet. Urinary cadmium (uCd) reflects long-term exposure and has been frequently used to assess cadmium exposure in epidemiological studies; estimated dietary intake of cadmium (dCd) has also been used in several studies. The validity of dCd in comparison with uCd is unclear. This study aimed to compare dCd, estimated from food frequency questionnaires, to uCd measured in spot urine samples from 1,002 participants of the Women's Health Initiative. Using linear regression, we found that dCd was not statistically significantly associated with uCd (β=0.006, P-value=0.14). When stratified by smoking status, dCd was not significantly associated with uCd both in never smokers (β=0.006, P-value=0.09) and in ever smokers (β=0.003, P-value=0.67). Our results suggest that because of the lack of association between estimated dCd and measured uCd, dietary estimation of cadmium exposure should be used with caution in epidemiologic studies.

Triclosan and bisphenol a affect decidualization of human endometrial stromal cells

In recent years, impaired fertility and endometrium related diseases are increased. Many evidences suggest that environmental pollution might be considered a risk factor for endometrial physiopathology. Among environmental pollutants, endocrine disrupting chemicals (EDCs) act on endocrine system, causing hormonal imbalance which, in turn, leads to female and male reproductive dysfunctions. In this work, we studied the effects of triclosan (TCL) and bisphenol A (BPA), two widespread EDCs, on human endometrial stromal cells (ESCs), derived from endometrial biopsies from woman not affected by endometriosis. Cell proliferation, cell cycle, migration and decidualization mechanisms were investigated. Treatments have been performed with both the EDCs separately or in presence and in absence of progesterone used as decidualization stimulus. Both TCL and BPA did not affect cell proliferation, but they arrested ESCs at G2/M phase of cell cycle enhancing cell migration. TCL and BPA also increased gene expression and protein levels of some decidualization markers, such as insulin growth factor binding protein 1 (IGFBP1) and prolactin (PRL), amplifying the effect of progesterone alone. All together, our data strongly suggest that TCL and BPA might alter human endometrium physiology so affecting fertility and pregnancy outcome.

Association Between Cd Exposure and Risk of Prostate Cancer: A PRISMA-Compliant Systematic Review and Meta-Analysis

Several observational studies on the association between Cd exposure and risk of prostate cancer have yielded inconsistent results. To address this issue, we conducted a meta-analysis to evaluate the correlation between Cd exposure and risk of prostate cancer.Relevant studies in PubMed and Embase databases were retrieved until October 2015. We compared the highest and lowest meta-analyses to quantitatively evaluate the relationship between Cd exposure and risk of prostate cancer. Summary estimates were obtained using a random-effects model.In the general population, high Cd exposure was not associated with increased prostate cancer (OR 1.21; 95% CI 0.91-1.64), whereas the combined standardized mortality ratio of the association between Cd exposure and risk of prostate cancer was 1.66 (95% CI 1.10-2.50) in populations exposed to occupational Cd. In addition, high D-Cd intake (OR 1.07; 95% CI 0.96-1.20) and U-Cd concentration (OR 0.86; 95% CI 0.48-1.55) among the general population was not related to the increased risk of prostate cancer. In the dose analysis, the summary relative risk was 1.07 (95% CI 0.73-1.57) for each 0.5 μg/g creatinine increase in U-Cd and 1.02 (95% CI 0.99-1.06) for each 10 μg/day increase of dietary Cd intake. However, compared with nonoccupational exposure, high occupational Cd exposure may be associated with the increased risk of prostate cancer.This meta-analysis suggests high Cd exposure as a risk factor for prostate cancer in occupational rather than nonoccupational populations. However, these results should be carefully interpreted because of the significant heterogeneity among studies. Additional large-scale and high-quality prospective studies are needed to confirm the association between Cd exposure and risk of prostate cancer.

A novel fluorene based “turn on” fluorescent sensor for the determination of zinc and cadmium: experimental and theoretical studies along with live cell imaging

A new “naked-eye” colorimetric and fluorometric chemosensor HAFPA synthesized form both 1 : 1 and 1 : 2 complexes with Zn²⁺ and only 1 : 1 complex with Cd²⁺ which can detect intracellular Zn²⁺ and Cd²⁺ in A549 cells.

Dietary exposure to cadmium and risk of breast cancer in postmenopausal women: A systematic review and meta-analysis

BACKGROUND

With tobacco smoking, diet is the main source of cadmium (Cd) exposure in the general population. The carcinogenic and estrogenic activities of Cd make it a contaminant of potential concern for hormone-dependent cancers including breast cancer. Postmenopausal women represent the most appropriate population to investigate the possible impact of exogenous factors with potential estrogenic activity on breast cancer as, after menopause, their estrogenic influence is predominant.

OBJECTIVES

We systematically reviewed available studies on the association between dietary exposure to Cd and breast cancer focusing on postmenopausal women. A meta-analysis combining the risk estimators was performed and potential sources of between studies heterogeneity were traced.

METHODS

Studies were searched from MEDLINE through 31 January 2015 and from the reference lists of relevant publications. Six eligible studies published between 2012 and 2014 were identified and relative risk estimates were extracted. Meta-rate ratio estimates (mRR) were calculated according to fixed and random-effect models. Meta-analyses were performed on the whole set of data and separate analyses were conducted after stratification for study design, geographic location, use of hormone replacement therapy (HRT), tumor estrogen receptor status (ER+ or ER-), progesterone receptor status (PGR+ or PGR-), body mass index (BMI), smoker status, zinc or iron intake.

RESULTS

No statistically significant increased risk of breast cancer was observed when all studies were combined (mRR=1.03; 95% confidence interval [CI]: 0.89-1.19). Several sources of heterogeneity and inconsistency were identified, including smoker status, HRT use, BMI, zinc and iron intake. Inconsistency was also strongly reduced when only considering ER-, PGR-, tumors subgroups from USA and from Japan. The risks were, however, not substantially modified after stratifications. No evidence of publication bias was found.

CONCLUSION

The present study does not provide support for the hypothesis that dietary exposure to Cd increases the risk of breast cancer in postmenopausal women. Misclassification in dietary Cd assessment in primary studies could have biased the results towards a finding of no association.

A selective fluorescent probe for the detection of Cd2+ in different buffer solutions and water

A fluorescent probe NHQ, which exhibited excellent selectivity toward Cd²⁺ in different buffer solutions such as Tris-HCl buffer solution, HEPES buffer solution, and PBS buffer solution, and even in water, was developed.

Metal concentrations in hair of patients with various head and neck cancers as a diagnostic aid

Head and neck cancers are one of the most frequent cancers worldwide. This paper attempts to evaluate disturbances of homeostasis of the necessary elements (calcium, magnesium, zinc, copper, iron, manganese) and changes in the levels of toxic metals (lead, cadmium, cobalt, chromium VI) in hair of patients with head and neck cancers, as well as people without a diagnosed neoplastic disease. In order to quantify the necessary elements and toxic metals, a method using ICP-MS and ICP-OES techniques had been developed and validated. The studies have shown that patients with head and neck cancer used to drink alcohol and smoked much more frequently than healthy individuals, both in the past and presently. Statistically significant differences in concentrations of average metal content in the group of patients with head and neck cancers compared to the control group were confirmed. Significant differences in metal content between the group of patients with head and neck cancers and healthy individuals were found which enabled distinguishing between the study groups. To this end, a more advanced statistical tool, i.e. chemometrics, was used. The conducted research analyses and the use of advanced statistical techniques confirm the benefits of using alternative material to distinguish the patients with head and neck cancers from the healthy individuals.

A new visible-light-excitable ICT-CHEF-mediated fluorescence 'turn-on' probe for the selective detection of Cd(2+) in a mixed aqueous system with live-cell imaging

A new quinoline based sensor was developed and applied for the selective detection of Cd(2+) both in vitro and in vivo. The designed probe displays a straightforward approach for the selective detection of Cd(2+) with a prominent fluorescence enhancement along with a large red shift (∼38 nm), which may be because of the CHEF (chelation-enhanced fluorescence) and ICT (internal charge transfer) processes after interaction with Cd(2+). The interference from other biologically important competing metal ions, particularly Zn(2+), has not been observed. The visible-light excitability of the probe merits in the viewpoint of its biological application. The probe enables the detection of intracellular Cd(2+) with non-cytotoxic effects, which was demonstrated with the live RAW cells. The experimentally observed change in the structure and electronic properties of the sensor after the addition of Cd(2+) were modelled by the density functional theory (DFT) and time-dependent density functional theory (TDDFT) computational calculations, respectively. Moreover, the test strip experiment with this sensor exhibits both absorption and fluorescence color changes when exposed to Cd(2+) in a mixed aqueous solution, which also makes the probe more useful. The minimum limit of detection of Cd(2+) by the probe was in the range of 9.9 × 10(-8) M level.

Environmentally Realistic Doses of Cadmium as a Possible Etiologic Agent for Idiopathic Pathologies

Cadmium is a heavy metal of increasing environmental concern that has long been associated to several human pathological processes. Recent population surveys have correlated cadmium non-occupational exposure to widespread idiopathic pathologies. Food and tobacco are reported to be the main exposure sources of cadmium to the general population, as phosphate fertilizers are rich in such a metal, thus contaminating the crops. Although its mechanisms of toxicity are not a consensus in the literature, it is well established that reactive oxygen species play a key role in this process, leading to the oxidation of several biological molecules. We have therefore assessed whether three environmentally realistic doses of cadmium alter the oxidative status of Wistar rat testis and eventually result in histological damages. Our results show that even the lowest environmental dose of cadmium was able to disturb the endogenous antioxidant system in Wistar testis, although an increase in lipid peroxidation was observed only within the group exposed to the highest environmental dose. Despite that no remarkable morphological changes were observed in any group, significant alterations in blood vessel lumen were reported for some cadmium-exposed animals, suggesting that endothelium is one of the primary targets involved in cadmium toxicity.

Dietary Intake Estimates and Urinary Cadmium Levels in Danish Postmenopausal Women

BACKGROUND

Cadmium is a known carcinogen that can disrupt endocrine signalling. Cigarette smoking and food are the most common routes of non-occupational exposure to cadmium. Cadmium accumulates in the kidney and can be measured in urine, making urine cadmium (U-Cd) a biomarker of long-term exposure. However dietary-cadmium (D-Cd) intake estimates are often used as surrogate indicator of cadmium exposure in non-smoking subjects. It is therefore important to investigate the concordance between D-Cd estimates obtained with Food Frequency Questionnaires and U-Cd.

METHODS

U-Cd levels were compared with estimated dietary-cadmium (D-Cd) intake in 1764 post-menopausal women from the Danish Diet, Cancer and Health cohort. For each participant, a food frequency questionnaire, and measures of cadmium content in standard recipes were used to judge the daily intake of cadmium, normalized by daily caloric intake. Cadmium was measured by ICP-MS in spot urine sampled at baseline and normalized by urinary creatinine. Information on diet, socio-demographics and smoking were self-reported at baseline.

RESULTS

Linear regressions between U-Cd and D-Cd alone revealed minimal but significant positive correlation in never smokers (R2 = 0.0076, β = 1.5% increase per 1 ng Cd kcal(-1), p = 0.0085, n = 782), and negative correlation in current smokers (R2 = 0.0184, β = 7.1% decrease per 1 ng Cd kcal(-1) change, p = 0.0006, n = 584). In the full study population, most of the variability in U-Cd was explained by smoking status (R2 = 0.2450, n = 1764). A forward selection model revealed that the strongest predictors of U-Cd were age in never smokers (Δ R2 = 0.04), smoking duration in former smokers (Δ R2 = 0.06) and pack-years in current smokers (Δ R2 = 0.07). Food items that contributed to U-Cd were leafy vegetables and soy-based products, but explained very little of the variance in U-Cd.

CONCLUSIONS

Dietary-Cd intake estimated from food frequency questionnaires correlates only minimally with U-Cd biomarker, and its use as a Cd exposure indicator may be of limited utility in epidemiologic studies.

Additional Burden of Diseases Associated with Cadmium Exposure: A Case Study of Cadmium Contaminated Rice Fields in Mae Sot District, Tak Province, Thailand

The cadmium (Cd) contaminated rice fields in Mae Sot District, Tak Province, Thailand has been one of the major environmental problems in Thailand for the last 10 years. We used disability adjusted life years (DALYs) to estimate the burden of disease attributable to Cd in terms of additional DALYs of Mae Sot residents. Cd exposure data included Cd and β₂–microglobulin (β₂-MG) in urine (as an internal exposure dose) and estimated cadmium daily intake (as an external exposure dose). Compared to the general Thai population, Mae Sot residents gained 10%–86% DALYs from nephrosis/nephritis, heart diseases, osteoporosis and cancer depending on their Cd exposure type and exposure level. The results for urinary Cd and dietary Cd intake varied according to the studies used for risk estimation. The ceiling effect was observed in results using dietary Cd intake because of the high Cd content in rice grown in the Mae Sot area. The results from β₂-MG were more robust with additional DALYs ranging from 36%–86% for heart failure, cerebral infarction, and nephrosis/nephritis. Additional DALYs is a useful approach for assessing the magnitude of environmental Cd exposure. The Mae Sot population lost more healthy life compared to populations living in a non- or less Cd polluted area. This method should be applicable to various types of environmental contamination problems if exposure assessment information is available.

Epigenetic marks responsible for cadmium-induced melanoma cell overgrowth

Cadmium (Cd) is a human carcinogen that likely acts via epigenetic mechanisms. However, the precise role of Cd in melanoma remains to be defined. The goals of this study are to: (i) examine the effect of Cd on the proliferation rate of cutaneous and uveal melanoma cells; (ii) identify the genes affected by Cd exposure; (iii) understand whether epigenetic changes are involved in the response to Cd. The cell growth capacity increased at 48 h after Cd treatment at doses ranging from 0.5 to 10 μM. The research on the key genes regulating proliferation has shown that aberrant methylation is responsible for silencing of p16(INK4A) and caspase 8 in uveal and cutaneous melanoma cells, respectively. The methylation and expression patterns of p14(ARF), death receptors 4/5, and E-cadherin remained unmodified after Cd treatment in all the cell lines analyzed. Ectopic expression of p16(INK4A) abolished the overgrowth of uveal melanoma cells in response to Cd and the overexpression of caspase 8 drastically increased the apoptotic rate of Cd-treated cutaneous melanoma cells. In conclusion, our data suggest that hypermethylation of p16(INK4A) and caspase 8 represents the most common event linked to Cd-induced stimulation of cell growth and inhibition of cell death pathway in melanoma.

Blood cadmium burden and the risk of nasopharyngeal carcinoma: a case-control study in Chinese Chaoshan population

Cadmium is a ubiquitous carcinogenic pollutant with multiple biological effects. Both observational and experimental studies have suggested associations between cadmium and the rates of many types of cancers. The aim of the present study was to evaluate whether cadmium exposure is associated with nasopharyngeal carcinoma (NPC) in a population with a relatively high prevalence in southeast China. Hospital-based 134 NPC cases and 132 cancer-free controls were recruited from a cancer hospital in Chaoshan area, southeast of China. Basic clinical data and information of lifetime styles, smoking, and drinking as well as other demographic characteristics were also collected from medical records. Blood cadmium levels (BCLs) were detected by graphite-furnace atomizer absorption spectrophotometer (GFAAS). BCLs and over-limit ratios between cases and controls were compared. The relationships between BCLs and NPC were explored by comparing BCLs differences between/among different characteristics of related factors and logistic regression analysis. In addition, BCLs within cases were also compared in relation to the disease clinical stages, pathological types, and metastasis. The median concentration of blood cadmium in cases (3.84, interquartile range 2.21-6.10) was significantly higher than that of controls (2.28, interquartile range 1.79-3.45). The over-limit ratio (≥5 μg/L) in cases was also higher than that in controls (35.1 vs. 13.6%, χ(2) = 16.55, p < 0.001). Smokers tended to have high levels of cadmium burden, and smokers with longer smoking pack-years in cases had relatively higher BCLs (p = 0.001). NPC patients with diseases history presented lower cadmium burden (p = 0.020). In the NPC cases, BCLs were positively associated with clinical stages and N classification (r = 0.193, 0.187, respectively, p < 0.05). Cadmium seems to be a risk factor of NPC, and high cadmium exposure may promote the occurrence and development of NPC.

Inverse association between coffee consumption and risk of cholecystectomy in women but not in men

BACKGROUND & AIMS

There is conflicting epidemiologic evidence on whether coffee consumption reduces the risk of gallstone disease. We examined the association between coffee consumption and risk of cholecystectomy (as a proxy for symptomatic gallstone disease) in a prospective cohort study.

METHODS

We collected data from 30,989 women (born 1914-1948) and 40,936 men (born 1918-1952) from the Swedish Mammography Cohort and the Cohort of Swedish Men. Baseline information on coffee consumption was collected by using a food-frequency questionnaire; subjects were followed up for procedures of cholecystectomy from 1998 through 2011 by linkage to the Swedish Patient Register. Hazard ratios (HRs) were estimated by using Cox proportional hazard models.

RESULTS

During a total follow-up period of 905,933 person-years, we identified 1057 women and 962 men who had undergone a cholecystectomy. After adjustment for potential confounders, the HR of cholecystectomy was 0.58 (95% confidence interval [CI], 0.44-0.78) for women who drank ≥6 cups of coffee/day compared with women who drank <2 cups/day. In contrast, there was no association in men (HR, 0.96; 95% CI, 0.75-1.24). Because of this sex difference, we examined and found evidence of effect modification by menopausal status and use of hormone replacement therapy (HRT) (Pinteraction = .026). An inverse association was observed only in women who were premenopausal (HR, 0.17; 95% CI, 0.05-0.55) or used HRT (HR, 0.44; 95% CI, 0.28-0.70).

CONCLUSIONS

We observed an inverse association between coffee consumption and risk of cholecystectomy in women who were premenopausal or used HRT but not in other women or in men.

Cadmium status among pediatric cancer patients in Egypt

Cadmium (Cd) is a toxic, nonessential, and bio-accumulating heavy metal widely used in industry. Several studies have suggested a positive association between Cd exposure and risks of several cancers. However, data from general population, especially children are sparse.In the current cross-sectional case-control study, we aimed to assess the association between Cd exposure, as expressed by Cd body status (blood, urine, scalp hair, and nails) and cancer among Egyptian children. Three hundred and fifty pediatric cancer cases aged 3 to 14-years old were enrolled in our study. Their body Cd levels were evaluated using Atomic Absorption Spectrophometer and were compared with Cd levels of 350 healthy children.Significantly higher Cd levels (blood, urine, scalp hair, and nails) were documented in cancer cases when compared with control (P < 0.001). Such difference was still detected when comparing each malignant type separately, with controls. Tobacco smoke exposure, rural residence, and low socioeconomic status were reported more frequently among cases than comparisons.Positive association between Cd exposure and pediatric malignancy may be present.

A fluorescent chemosensor for Hg(2+) and Cd(2+) ions in aqueous medium under physiological pH and its applications in imaging living cells

A new BODIPY derivative with 2,2'-(ethane-1,2-diylbis(oxy))bis(N,N-bis(pyridine-2-ylmethyl)aniline unit as the metal receptor has been designed and synthesized. The dye selectively detects either Cd(2+) or Hg(2+) ions in the presence of hosts of other biologically important and environmentally relevant metal ions in aqueous medium at physiological pH. Binding of metal ions causes a change in the emission behavior of the dye from weakly fluorescent to highly fluorescent. Confocal microscopic experiments validate that the dye can be used to identify changes in either Hg(2+) or Cd(2+) levels in living cells.

Association between dietary cadmium exposure and breast cancer risk: an updated meta-analysis of observational studies

BACKGROUND

Diet is the primary way cadmium (Cd) enters the body in those without occupational exposure and who do not inhabit Cd-polluted regions. Findings on the relationship between dietary Cd exposure and breast cancer (BC) risk have been inconsistent; a meta-analysis has supported this association but 2 recent cohort studies showed inconsistent results. Hence, we performed an updated meta-analysis to re-evaluate the association between dietary Cd exposure and BC risk.

MATERIAL AND METHODS

We searched PubMed, Medline, and EMBASE to identify relevant studies published through September 2014. Combined relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were used to assess the association between dietary Cd exposure and BC risk.

RESULTS

We identified 6 studies involving 321 315 participants and 11 978 cases. Our study suggested there was no statistically significant positive association between dietary Cd exposure and BC risk, the combined RR and corresponding 95% CI was 1.01 [0.88, 1.14]. The result was not modified by menopause status, geographic area, or study design.

CONCLUSIONS

Our study did not find a statistically significant positive association between dietary Cd exposure and BC risk. It is necessary to investigate this relationship among the high-risk groups and more cohort studies based on diverse populations are needed.

Epigenetic effects of cadmium in cancer: focus on melanoma

Cadmium is a highly toxic heavy metal, which has a destroying impact on organs. Exposure to cadmium causes severe health problems to human beings due to its ubiquitous environmental presence and features of the pathologies associated with pro-longed exposure. Cadmium is a well-established carcinogen, although the underlying mechanisms have not been fully under-stood yet. Recently, there has been considerable interest in the impact of this environmental pollutant on the epigenome. Be-cause of the role of epigenetic alterations in regulating gene expression, there is a potential for the integration of cadmium-induced epigenetic alterations as critical elements in the cancer risk assessment process. Here, after a brief review of the ma-jor diseases related to cadmium exposure, we focus our interest on the carcinogenic potential of this heavy metal. Among the several proposed pathogenetic mechanisms, particular attention is given to epigenetic alterations, including changes in DNA methylation, histone modifications and non-coding RNA expression. We review evidence for a link between cadmium-induced epigenetic changes and cell transformation, with special emphasis on melanoma. DNA methylation, with reduced expression of key genes that regulate cell proliferation and apoptosis, has emerged as a possible cadmium-induced epigenetic mechanism in melanoma. A wider comprehension of mechanisms related to this common environmental contaminant would allow a better cancer risk evaluation.

The influence of long-term cadmium exposure on phonotaxis in male Pelophylax nigromaculata

Cadmium (Cd) is a common industrial and agricultural heavy metal found in the natural environment that disrupts the endocrine systems of vertebrates. Amphibians are particularly vulnerable to endocrine disruptors because of their aquatic habitats and permeable skin. Endocrine disruptors are known to negatively affect amphibian acoustic behavior, but whether and how the ubiquitous pollutant Cd impacts this crucial amphibian signaling system remains unknown. Male black-spotted frogs (Pelophylax nigromaculata) show phonotactic responses to female receptive calls by emitting advertisement calls and moving towards females during the mating season, essential for reproductive success. To study whether long-term (60 d) exposure to low Cd concentrations (10(-8), 10(-7) and 10(-6) M) affects male phonotaxis, we recorded male responses to female calls following Cd exposure during the breeding season. We found that Cd adversely affected advertisement call characteristics (call latency, call duration and call rate), the proportion of individuals that responded and the time to first movement of the male. These results indicate that long-term exposure to Cd at environmentally relevant concentrations alters phonotaxis in male P. nigromaculata.

Fish consumption and risk of non-gallstone-related acute pancreatitis: a prospective cohort study

BACKGROUND

Epidemiologic data on the role of diet in acute pancreatitis are sparse.

OBJECTIVE

We examined the association of total fish consumption, as well as of consumption of fatty fish and lean fish separately, with risk of non-gallstone-related acute pancreatitis.

DESIGN

We used data from 2 prospective cohorts, the Cohort of Swedish Men and the Swedish Mammography Cohort, that included 39,267 men and 32,191 women who were aged 45-84 y at the start of a 13-y follow-up period (1998-2010). Fish consumption was assessed by using a food-frequency questionnaire at baseline, and cases of incident non-gallstone-related acute pancreatitis were identified by linkage to the Swedish National Patient Register. HRs were estimated by using Cox proportional hazard models.

RESULTS

During a total follow-up of 860,176 person-years, 320 cases (209 cases in men and 111 cases in women) of incident non-gallstone-related acute pancreatitis were identified. We observed that total fish consumption ≤2.0-3.0 servings/wk was associated with a significantly decreased risk of the disease (P-nonlinearity = 0.017). In comparison with 0.9 servings/wk, multivariable-adjusted HRs were 0.86 (95% CI: 0.76, 0.96), 0.77 (95% CI: 0.62, 0.96), and 0.85 (95% CI: 0.65, 1.10) for 1.4, 2.4, and 3.5 servings/wk, respectively. In the analysis of fatty fish and lean fish, we observed that the consumption of each subtype had a similarly shaped association with risk of non-gallstone-related acute pancreatitis as that observed for total fish consumption, although neither was significant. Multivariable-adjusted HRs were 0.83 for fatty fish (95% CI: 0.65, 1.04) and 0.87 for lean fish (95% CI: 0.69, 1.11) when 0.6-2.0 servings/wk was compared with ≤0.5 servings/wk.

CONCLUSION

Our data suggest that the consumption of total fish (fatty fish and lean fish combined) may be associated with decreased risk of non-gallstone-related acute pancreatitis.

Cadmium exposure and atherosclerotic carotid plaques--results from the Malmö diet and Cancer study

BACKGROUND

Epidemiological studies indicate that cadmium exposure through diet and smoking is associated with increased risk of cardiovascular disease. There are few data on the relationship between cadmium and plaques, the hallmark of underlying atherosclerotic disease.

OBJECTIVES

To examine the association between exposure to cadmium and the prevalence and size of atherosclerotic plaques in the carotid artery.

METHODS

A population sample of 4639 Swedish middle-aged women and men was examined in 1991-1994. Carotid plaque was determined by B-mode ultrasound. Cadmium in blood was analyzed by inductively coupled plasma mass spectrometry.

RESULTS

Comparing quartile 4 with quartile 1 of blood cadmium, the odds ratio (OR) for prevalence of any plaque was 1.9 (95% confidence interval 1.6-2.2) after adjustment for sex and, age; 1.4 (1.1-1.8) after additional adjustment for smoking status; 1.4 (1.1-1.7) after the addition of education level and life style factors; 1.3 (1.03-1.8) after additional adjustment for risk factors and predictors of cardiovascular disease. No effect modification by sex was found in the cadmium-related prevalence of plaques. Similarly, ORs for the prevalence of small and large plaques were after full adjustment 1.4 (1.0-2.1) and 1.4 (0.9-2.0), respectively. The subgroup of never smokers showed no association between cadmium and atherosclerotic plaques.

CONCLUSIONS

These results extend previous studies on cadmium exposure and clinical cardiovascular events by adding data on the association between cadmium and underlying atherosclerosis in humans. The role of smoking remains unclear. It may both cause residual confounding and be a source of pro-atherogenic cadmium exposure.