Copper,zinc, and selenium in whole blood and thyroid tissue of people with various thyroid diseases

We investigated the possible differences among the concentrations of copper, zinc, and selenium, and their mutual relations in the whole blood and thyroid tissue of patients with various thyroid disorders. Trace elements were determined by total-reflection X-ray fluorescence. The mean levels of these metals in blood as well as the mean Cu/Zn, Cu/Se, and Zn/Se ratios in the patients with thyroid cancer were significantly higher that in other patients and the control groups. However, the mean Zn and Se concentrations in the thyroid cancer tissue were significantly lower than in the thyroid tissue of other patients. In addition, the mean Cu/Zn and Cu/Se ratios in the thyroid cancer tissue were significantly higher than in the patients with other thyroid diseases. We confirm that the highest levels of copper and zinc as well as the Cu/Zn, Cu/Se, and Zn/Se ratios in the whole blood of the patients with thyroid cancer may suggest the progression of the proliferation process in the thyroid gland. We suggest that the low concentrations of zinc and selenium in the thyroid tissue confirm their participation in the carcinogenic process.     

Serum copper,zinc levels,and copper

Serum copper and zinc levels were determined in 20 healthy women and in 100 women with gynecological tumors. Malignant and benign tumor cases were separated according to their postoperative, histopathological examinations. The stages of malignant and benign tumors were also established histologically. Seventy benign and 30 malignant genital tumors (carcinoma of cervix in situ, cervix, ovary endometrium, and vulva) of the patients were differentiated histopathologically. The serum Cu/Zn ratios of patients were increased significantly from the control group (0.32±0.35) to the benign group (1.22±0.63) and from the benign group to the malignant group (2.24±1.03). Nine of 30 malignant cases were determined as false negative (30%) and 15 of 70 benign cases were determined as false positive (14.2%) according to the serum Cu/Zn ratios of patients. Serum copper levels of 30 malignant and 10 benign tumor cases showed linear correlation with serum ceruloplasmin values.     

Serum and tissue trace elements in patients with breast cancer in Taiwan

The objective of this study was to compare levels of four elements (zinc, copper, selenium, and iron) in the serum and tissue of 68 breast tumor patients (benign and malignant), from a teaching hospital in central Taiwan. Samples of normal tissue (5 cm away from tumor) were also taken from patients with malignant tumors. Only serum was taken from the 25 healthy persons in the control group. Results showed that Zn, Cu, Se, Fe, Cu/Zn, Cu/Se, and Cu/Fe were present in different amounts in the serum of each of the three groups. Zn and Se levels were lower in the serum of the two tumor groups compared to the control group. In tissue samples, Zn, Cu, Se, and Fe concentrations were different in each of the three groups. The malignant tissue had the highest levels of all four elements. In advanced-stage malignant tumors, levels of Cu and the ratios of Cu/Fe and Cu/Zn (in both serum and tissue) were highest. The ratios of serum Cu/Zn, Cu/Fe, and Cu/Se were also higher in malignant patients. The cutoff value of serum Cu/Zn was 1.2 (sensitivity and specificity were both 100%). The Cu/Zn ratio was highest in the advanced stages of cancer and was a better diagnostic tool for breast cancer than Cu/Se and Cu/Fe. The authors suggest that change of trace elements in serum and tissue might be useful and significant as biomarkers involving the initial plastic process.     

Efficiency of serum copper/zinc ratio for differential diagnosis of patients with and without lung cancer

We examined serum copper (Cu), serum zinc (Zn), and the serum copper/zinc ratio (Cu/Zn) in 162 patients. All of them were seen to have an abnormal shadow in the chest X-ray films, that is, 109 patients with lung cancer (LC) and 53 patients with no lung cancer (NLC). The mean Cu and Cu/Zn in LC patients were significantly higher than those in NLC patients (p<0.05). In LC patients, Cu and Cu/Zn were higher and Zn was lower in advanced tumors than early ones. There was a significantly clear relation between Cu or Cu/Zn and the tumor (T) stages. When the relative risk (RR) of LC was estimated, it was seen that the higher Cu and Cu/Zn became, the higher RR became. Furthermore, we showed the sensitivity of the receiver operator characteristic of the test (ROC) curve for Cu, Cu/Zn, and carcinoembryonic antigen (CEA) to diagnose LC, as explained in a paragraph of methods.The determinations of Cu, Zn, and Cu/Zn are simple and inexpensive. They also appear to have a great diagnostic value in determining the local invasion of LC and as a screening test in the high-risk patients for LC.     

Zinc is a constituent of bovine heart cytochrome c oxidase preparations

Cytochrome c oxidase preparations from bovine heart muscle contain 1 zinc per 2 irons. Metal contents of nine preparations determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) show that Cu, Fe and Zn are the only metals present in significant amounts with average Cu/Fe, Fe/Zn, and Cu/Zn atom ratios of 1.3, 2.1 and 2.8, respectively. Removal of adventitious copper results in a Cu:Fe:Zn stoichiometry of 2:2:1. The zinc is tightly bound. Dialysis against a solution of 1,10-phenanthroline at pH 7.4 or an acidic buffer (pH 4.4) does not remove Zn. Dialysis against 0.8 M KCN at pH 10 causes partial loss of both Cu and Zn. This is the first evidence for the presence of Zn in a cytochrome c oxidase.     

Arachidonate 5 lipoxygenase expression in papillary thyroid carcinoma promotes invasion via MMP-9 induction

Arachidonate 5-lipoxygenase (ALOX5) expression and activity has been implicated in tumor pathogenesis, yet its role in papillary thyroid carcinoma (PTC) has not been characterized. ALOX5 protein and mRNA were upregulated in PTC compared to matched, normal thyroid tissue, and ALOX5 expression correlated with invasive tumor histopathology. Evidence suggests that PTC invasion is mediated through the induction of matrix metalloproteinases (MMPs) that can degrade and remodel the extracellular matrix (ECM). A correlation between MMP-9 and ALOX5 protein expression was established by immunohistochemical analysis of PTC and normal thyroid tissues using a tissue array. Transfection of ALOX5 into a PTC cell line (BCPAP) increased MMP-9 secretion and cell invasion across an ECM barrier. The ALOX5 product, 5(S)-hydroxyeicosatetraenoic acid also increased MMP-9 protein expression by BCPAP in a dose-dependent manner. Inhibitors of MMP-9 and ALOX5 reversed ALOX5-enhanced invasion. Here we describe a new role for ALOX5 as a mediator of invasion via MMP-9 induction; this ALOX5/MMP9 pathway represents a new avenue in the search for functional biomarkers and/or potential therapeutic targets for aggressive PTC.     

(Copper, zinc)--thionein in pig liver.

The concentrations of zinc and/or copper in the hepatic metallothionein of young (1–11 days, and 8 week-old) pigs correlate with the concentration of whole liver zinc. In the livers of adult animals only thionein-bound zinc correlates with total zinc. Although thionein-bound copper correlates with total copper in the livers of developing pigs, it shows a higher degree of correlation with whole liver zinc.Hepatic (copper, zinc) -thioneins, from either the young or the adult pig, in which the Cu : Zn ratio is high, are denatured on columns of DE cellulose, or during preparative electrophoresis. Preparations in which the Cu : Zn ratio is lower are resolved by ion-exchange chromatography into three forms, all of which contain both cations, but in differing ratios. Electrophoresis of a (copper, zinc) thionein that contains the two cations in 1 : atomic ratio yields zinc-thionein as a single distinct molecular species.     

Trace element uptake in liver cells. 2. Effect of different proteins in the medium on the uptake of copper and zinc by hepatoma cells

Cultured rat hepatoma cells (HTC-cells) were used to study the uptake of copper and zinc from a minimal salt-glucose medium, supplemented with albumin from different species or with ovalbumin. Competitive equilibrium dialysis showed that at low molar ratios of metal/protein (less than 1) the affinity for copper of human and bovine albumin was about equal, but that of dog albumin or ovalbumin was much lower. Only a small difference in affinity for zinc could be detected between human albumin and ovalbumin. Supplementing the medium with the different proteins the rate of copper uptake in the cell at a given molar Cu/protein ratio increased as follows: human albumin congruent to bovine albumin less than dog albumin less than ovalbumin. When the molar Cu/protein ratio was increased, a discontinuity was seen with all three albumin species at a ratio of about 1. In contrast, the zinc uptake mimics that of Cu/ovalbumin, and no discontinuity was observed using different molar Zn/protein ratios. These results indicate that the rate of copper and zinc uptake depends strongly on its affinity for the protein: a low affinity leads to a high uptake. The results suggest further that at physiologic concentrations zinc is taken up by a mechanism different from that for copper.     

Expression of TGF-β1, SNAI1 and MMP-9 is associated with lymph node metastasis in papillary thyroid carcinoma

TGF-β1, SNAI1 and MMP-9 are implicated in tumor invasion and metastasis. The purpose of this study was to examine TGF-β1, SNAI1 and MMP-9 expression in papillary thyroid carcinoma (PTC), and to assess association of TGF-β1, SNAI1 and MMP-9 expression with several clinicopathological indicators of PTC. TGF-β1, SNAI1 and MMP-9 protein expression in 83 PTCs and their matched normal thyroid specimens were analyzed using immunohistochemistry. The mRNA expression levels of TGF-β1, SNAI1 and MMP-9 in 12 fresh PTC specimens with lymph node metastasis (LNM), 12 fresh PTC specimens without LNM and their matched normal thyroid specimens were assessed by real-time RT-PCR. The results showed that the mRNA and protein expression levels of TGF-β1, SNAI1 and MMP-9 were significantly higher in PTCs than in their matched normal thyroid tissues. There were not significant differences in TGF-β1, SNAI1 and MMP-9 protein expression relative to age, gender, tumor size and TNM stage, except for MMP-9 whose protein expression correlated with tumor size. However, high mRNA and protein expression levels of TGF-β1, SNAI1 and MMP-9 were significantly correlated with LNM. Furthermore, TGF-β1, SNAI1 and MMP-9 protein expression were significantly correlated with one another. Concomitant expression of any two or all of the three molecules had stronger correlation with LNM than did each alone. Collectively, the present results indicate that immunohistochemical and real-time RT-PCR evaluation of TGF-β1, SNAI1 and MMP-9 expression in PTC may be useful to predict the risk of LNM in PTC patients.     

A comparative study of the soil zinc fractions determined by chemical methods and electro-ultrafiltration (EUF) and their relations to zinc nutrition in rice

Rice (IR 42) was grown on two soils differing in zinc status for 30 days with and without Zn under submerged conditions in pots. The fate of soil zinc was characterized by extraction of the soil successively with copper acetate and sodium hypochlorite and by EUF extraction. Most of the applied zinc was extracted by copper acetate and represented as complexed fraction. There exists a close and significnat relation between Cu(OAc)₂-extractable zinc and Zn extracted by EUF for 5 minutes at 50 volts (r=0.98). The EUF-extractable zinc and Cu(OAc)₂-extractable zinc were significantly correlated with the zinc content in the plant (r=0.82). The data from this investigation suggest the possibility of Zn fractionation with the EUF technique and the fractions obtained agree closely to those determined by chemical methods. The results obtained indicate that Zn in soil is held by weak organic bonding and that the extractions by Cu(OAc)₂ and/or EUF-5 minutes serve as a useful basis for extimating zinc availability in rice soils.     

Analysis of serum copper and zinc concentrations in cancer patients

Several studies have shown that plasma copper concentrations are increased in various carcinomas. Zinc acts as a cellular growth protector, including growth of neoplastic cells, and its deficiency was demonstrated to be involved in several stages of malignant transformation. However, the usefulness of the serum zinc and copper determinations in cancer prevention, detection, monitoring treatment, and prognosis requires further investigations. The aim of the present study was to compare the serum copper and zinc levels in patients with cancer of the lung (PC), breast (BC), gastrointestinal tract (GIC), and gynecological (GYNC) malignancy with progress of the disease. The results of the study have shown a significant increase in the mean total serum Cu levels and the serum Cu/Zn ratio in all patient groups with cancer compared to a control group. Increased mean serum concentrations and Cu/Zn ratios were found in the whole group (ALLC), and for the GIC and GYNC groups with local as well as metastasized (Meta) disease in comparison with the control group. The mean serum concentrations of Zn were decreased only in metastasized ALLC and GYNC groups.     

Selenium, iron, copper, and zinc levels and copper-to-zinc ratios in serum of patients at different stages of viral hepatic diseases

Viral hepatic diseases, especially those induced by the hepatitis B virus, can progress into more serious pathological outcomes and eventually to hepatocellular carcinoma. A growing body of evidence indicates that many trace elements play important roles in a number of carcinogenic processes that proceed through various mechanisms. To examine the status of trace elements during the development of hepatic carcinoma, we determined the selenium, iron, copper, and zinc levels and copper-to-zinc ratios in the serum of patients at different stages of viral hepatic disease. We observed significant changes in the selenium, iron copper, and zinc levels in the serum of patients having hepatocellular carcinoma, relative to those of healthy controls (p<0.05). The mean serum copper level in patients with hepatocellular carcinoma was significantly higher than that of the control group. In contrast, the mean selenium, iron, and zinc levels in patients having hepatocellular carcinoma were significantly lower than those of the control group. In addition, the mean zinc level in the serum of patients with hepatic cirrhosis was significantly lower than that of the control group (p<0.05). Moreover, we found markedly elevated Cu: Zn ratios (p<0.05) in patients having hepatic cirrhosis or hepatocellular carcinoma. Our findings imply that the levels of some trace elements, such as selenium, iron, copper, and zinc, and Cu:Zn ratios, might serve as biomarkers for the increased severity of viral hepatic damage.     

Indices of iron and copper status during experimentally induced,marginal zinc deficiency in humans

This study examined the effect of diet-induced, marginal zinc deficiency for 7 wks in 15 men (aged 25.3 +/- 3.3 yrs; mean +/- SD) on selected indices of iron and copper status. The regimen involved low-zinc diets based on egg albumin and soy protein with added phytate and calcium such that mean [phytate]/[Zn] and [phytate] X [Ca]/[Zn] molar ratios were 209 and 4116, respectively, for 1 wk, followed by 70 and 2000, respectively, for 6 wks. Subjects were then repleted with 30 mg Zn/d for 2 wks. Plasma copper, Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity in plasma and red blood cells (RBC), hemoglobin, hematocrit, and serum ferritin were determined weekly on fasting blood samples. Significant reductions (p less than 0.05) after 7 wks in RBC Cu,Zn-superoxide dismutase (49.5 +/- 7.2 vs 33.6 +/- 6.3 U/mg Hb) and serum ferritin (69.2 +/- 38.7 vs 53.8 +/- 33.7 micrograms/L) occurred; no comparable decline was noted for plasma Cu, hemoglobin, or hematocrit. Significant (p less than 0.05) but less consistent changes were also observed in plasma superoxide dismutase activity. None of the changes were associated with the decreases in plasma, urinary and hair zinc concentrations, and alkaline phosphatase activity in RBC membranes. Results indicate that the biochemical iron and copper status of the subjects was marginally impaired, probably from the dietary regimen that induced marginal zinc deficiency.     

Serum copper and zinc levels and copper/zinc ratio in patients with breast cancer

Serum copper, zinc levels, and the Cu/Zn ratio were evaluated in 31 patients with breast cancer and 35 healthy controls. Copper and zinc were determined by atomic absorbtion spectrophotometry. The mean serum copper level and the mean Cu/Zn ratio in patients with breast cancer were significantly higher than the control group (p<0.001 andp<0.001). In addition, the mean serum zinc level in patients with breast cancer was significantly lower than the control group (p<0.001). Neither serum copper and zinc levels nor the Cu/Zn ratio were of value in discriminating of the disease activity and severity. Interestingly, the Cu/Zn ratio in premenopausal patients was higher than postmenopausal patients (p<0.05) and this was not related to age. The further combined biological and epidemiological studies are necessary to investigate the roles of copper and zinc in breast cancer.     

Trace element concentrations and superoxide dismutase and catalase activities in benign and malignant larynx tumors

The plasma and erythrocyte levels of zinc, copper, and magnesium and the activities of red-cell copper-zinc superoxide dismutase (Cu/Zn-SOD) and catalase (CAT) were determined in patients with benign and malignant tumors of the larynx. Blood samples from patients and healthy controls were drawn using heparinized tubes. The erythrocyte Cu/Zn-SOD and CAT activities were determined spectrophotometrically and the zinc, copper, and magnesium concentrations were determined in erythrocyte and plasma by atomic absorption spectrometry. Variance analysis was employed in the statistical evaluation of the findings. There was a significant increase in red-cell Cu/Zn-SOD activity in the subjects with malignant and benign tumors compared to controls (p<0.001). The CAT activity increased only in the benign tumor group (p<0.01). The plasma zinc concentrations were significantly lower in the malignant tumor group (p<0.05) and significantly higher in the benign tumor group (p<0.01). The erythrocyte copper concentrations were significantly lower in both benign and malignant tumor groups (p<0.001). The plasma copper and magnesium and the erythrocyte magnesium concentrations did not show significant differences relative to controls (p>0.05). The increases in the activities of SOD and CAT activities and the changes in trace elements concentrations can indicate the presence of increased reactive oxygen species that might play a part in the pathogenesis larynx tumors. Presented at the IX Asian-Pacific Congress of Clinical Biochemistry, March 9–14, 2002, New Delhi, India.     

Displacement of zinc and copper from copper-induced metallothionein by cadmium and by mercury: in vivo and ex vivo studies

The in vitro affinity of metals for metallothionein (MT) is Zn less than Cd less than Cu less than Hg. In a previous study Cd(II) and Hg(II) displaced Zn(II) from rat hepatic Zn7-MT in vivo and ex vivo (Day et al., 1984, Chem. Biol. Interact. 50, 159-174). The ability of Cd(II) or Hg(II) to displace Zn(II) and/or Cu(II) from metallothionein in copper-preinduced rat liver (Zn, Cu-MT) was assessed. Cd(II) and Hg(II) can displace zinc from (Zn, Cu)-MT both in vivo and ex vivo. The in vitro displacement of copper from MT by Hg(II) was not confirmed in vivo and ex vivo. Cd(II) treatment did not alter copper levels in (Zn, Cu)-MT, as expected. Hg(II) treatment, however, did not decrease copper levels in MT, but rather increased them. The sum of the copper increase and mercury incorporation into MT matched the zinc decrease under in vivo conditions and actually exceeded the zinc decrease under ex vivo conditions. Short-term exposure of rat liver to exogenous metals can result in incorporation of these metals into MT by displacement of zinc from pre-existing MT. Displacement of copper from pre-existing MT by mercury, as predicted by in vitro experiments, was not confirmed under the conditions of our in vivo and ex vivo experiments. This result is explainable based on the differing affinities and/or preferences of the two metal clusters in MT.     

Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat.

A study has been made of the mechanism of the mutual antagonism between copper and zinc in rats. Dietary zinc concentrations of up to 450 mg/kg had no effect on intestinal 64Cu absorption but 900 mg/kg caused a 40% reduction. This was associated with an increase in the mucosal uptake of 64Cu in the small intestine. This occurred mainly in the form of metallothionein and it appeared that copper displaced zinc from the protein after its synthesis had been induced by zinc. Ths intestinal absorption of 65Zn was decreased by 20% when the dietary copper intake was increased from 3 to 24 mg/kg. Further increases in copper intake to 300 mg/kg did not cause any additional decrease in 65Zn absorption or any change in the association of intestinal 65Zn with metallothionein. Concentrations of this protein in the intestinal mucosa were not influenced by dietary copper intake.     

Thyroid Function and Serum Copper,Selenium, and Zinc in General U.S. Population

Association of the levels of serum selenium (Se), zinc (Zn), and copper (Cu) with thyroid function was assessed by analyzing data from National Health and Nutrition Examination Survey for the cycle 2011–2012. Thyroid function variables analyzed were as follows: thyroid-stimulating hormone (TSH), free and total triiodothyronine (FT3, TT3), free and total thyroxine (FT4, TT4), and thyroglobulin (TGN). Regression models with log-transformed values of thyroid hormones as independent variables and age, race/ethnicity, smoking and iodine sufficiency status, respondents’ education, and levels of Se, Zn, and Cu as dependent variables were fitted. For males, levels of Zn were associated with decreased levels of FT4 and TT4, and levels of Cu were associated with increased levels of FT4 and TT4. For females, levels of Cu were associated with increased levels of TT3 and TT4. Smoking was found to be associated with lower levels of TSH and higher levels of TGN in males. Smoking was found to be associated with lower levels of TT4 in females. Males had about 5–10 % higher levels of both Se and Zn, but as much as 20 % lower levels of Cu than females. Smoking was associated with lower levels of Zn, but higher levels of Cu in males.     

Serum copper and zinc concentrations in a representative sample of the Canarian population.

Serum copper (Cu) and zinc (Zn) concentrations of 395 individuals (187 males + 208 females) living in Canary Islands were determined by flame atomic absorption spectrometry. The mean copper and zinc concentrations were 1.10 +/- 0.25 mg/L and 1.16 +/- 0.52 mg/L respectively. Our data were similar to other data published in other Spanish regions. Individuals from Lanzarote presented a mean Cu and Zn concentrations higher (p < 0.05) than individuals from the rest of islands; Individuals from EL Hierro showed the lowest (p < 0.05) mean Zn concentration. These differences could be attributed a differences in Cu and Zn contents of soil and/or differences in dietary habits of the populations. The mean serum Cu concentration in females was higher (p < 0.05) than in males, however serum Zn concentration did not vary with the sex of the subjects. No relation to socio-economic status and educational level were found with respect to the serum Cu and Zn concentrations. The serum Cu concentration varied with age of individuals, observing the highest (p < 0.05) Cu concentration in the 20-30 year old interval. A higher serum Cu concentration in females within 20-30 year old interval was observed. This could be due to a higher use of oral contraceptives or to the higher number of pregnancies. Boys (younger than 15) showed a decrease (p < 0.05) of the serum Cu concentration with age. The mean Zn concentrations in serum did not change (p > 0.05) among the different age intervals. No clear trends in the serum Cu and Zn concentrations were observed when drinking and smoking habits were considered. The increase of physical exercise reduced (p < 0.05) the serum Cu concentrations.