Dietary intake of Zinc, serum levels of Zinc and risk of gastric cancer: A review of studies

Trace Metal Accumulation in Rats Exposed to Mine Waters: A Case Study, Bor Area (Serbia)

Zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), cadmium (Cd), and lead (Pb) levels were measured in the Bor City water supply system (control) and two watercourses exposed to mining wastewaters, i.e., the Lutarica River (one site) and the Kriveljska River (two sites). The same parameters were determined in the brain, heart, lungs, stomach, liver, spleen, kidneys, and testes of male Wistar rats given water from these sources for 2 months. Water Cu, Fe, Cd, and Pb were outside the safe range, excepting the reference site. Significant impacts on intra-organ metal homeostasis were detected, especially in the brain, stomach, kidneys, and testes. The dynamics and magnitude of these changes (versus controls) depended on the target organ, analyzed metal, and water origin. The greatest number of significant intra-organ associations between essential and non-essential metals were found for Cd-Zn, Cd-Cu, and Cd-Mn. A regression analysis suggested the kidneys as the most relevant organ for monitoring water manganese, and the stomach and brain for lead. These results highlight the environmental risks associated with mining wastewaters from the Bor area and could help scientists in mapping the spatial distribution and severity of trace metal contamination in water sources.

Co-exposure to iron, copper, zinc, selenium and titanium is associated with the prevention of gastric precancerous lesions

Gastric cancer is the third leading cause of cancer death, and gastric precancerous lesions (GPLs) are an important stage in the transformation of normal gastric mucosa to gastric cancer. Matched for age and sex, a total of 316 subjects were eventually included from our prospective observation population (including 1007 patients with GPLs and 762 normal controls), and a questionnaire survey was conducted. In total, 10 plasma elements (iron, copper, zinc, selenium, rubidium, strontium, titanium, aluminum, vanadium and arsenic) were measured by applying inductively coupled plasma‒mass spectrometry (ICP‒MS). A multivariate conditional logistic regression model and Bayesian kernel logistic regression model (BKMR) were used to analyze the association between plasma element concentrations and GPLs. In the multimetal model, plasma titanium concentrations were significantly and positively associated with the prevalence of GPLs, with a fourth-quartile OR of 11.56 ([95% CI]: [2.78-48.13]). Plasma selenium and copper were negatively correlated with GPLs, with the highest quartiles of selenium and copper having an OR of 0.03 ([95% CI]: [0.01-0.15]; P < 0.001) and 0.24 ([95% CI]: [0.07-0.82]), respectively. In the BKMR model, there was a significant negative combined correlation of five metals on GPLs: iron, copper, zinc, selenium, and titanium. The results of this study showed that plasma concentrations of selenium and copper were negatively correlated with GPLs, while plasma concentrations of titanium were positively correlated with GPLs, and the combined action of the five elements was negatively correlated with GPLs.

Dietary zinc intake and mortality in patients with intestinal-type gastric cancer: A prospective cohort study in Korea

PURPOSE

Current evidence regarding the association between zinc intake and gastric cancer (GC)-specific survival in patients with intestinal-type GC is lacking. Therefore, this cohort study investigated the association between zinc intake and GC mortality through follow-up on GC death among patients with intestinal-type GC and whether these effects differ according to the source of zinc intake.

METHODS

A total of 185 patients with intestinal-type GC were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys.

RESULTS

A total of 178 patients were included and analyzed. The median follow-up period was 7.3 years. In the fully adjusted models, the highest tertile of total zinc intake showed a significantly lower GC mortality than the lowest tertile (hazard ratio, 0.22; 95% confidence interval: 0.08-0.64). In addition, the tertile of total zinc intake showed a dose-response association with GC mortality (p=0.015). Analysis of the source of zinc intake revealed that when zinc intake from staples (rice and noodles), animal, and plant food sources were combined, the results were similar to those of total zinc intake and GC mortality.

CONCLUSION

Zinc intake through various foods may be effective in reducing GC mortality by achieving balance with other nutrients. Our results suggest that zinc improves the survival of patients with intestinal-type GC in Korea.

The Transcription of ZIP9 Is Associated With the Macrophage Polarization and the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common digestive system cancers (DSCs) with a poor prognosis. Zinc‐regulated transporter (ZRT)/iron‐regulated transporter (IRT) like protein transporters (ZIPs) encode membrane transport proteins, which are responsible for the absorption of zinc and play important roles in the pathogenesis of various human cancers. Tumor-associated macrophages (TAMs) are important participants in the regulation of tumor microenvironment and the development of HCC. Individual role of each ZIP involved in hepatocarcinogenesis remains elusive. In this study, the transcription patterns of ZIPs in the DSCs were screened firstly through GEPIA2 database. Interestingly, the analysis of the DSCs data showed the distinct mRNA levels of ZIPs between DSCs tissues and healthy controls. Notably, the transcription levels of ZIP2, ZIP5, ZIP8, ZIP9 and ZIP14 were decreased significantly in the tissues of human liver cancer compared to paracarcinoma liver tissues. To further confirm the mRNA transcriptional changes of Zips in HCC, N-Nitrosodiethylamine (DEN) combined with carbon tetrachloride (CCl₄) inducing mouse model of HCC were established. Consistently, the mRNA levels of Zip2, Zip9, and Zip14 in liver tissues of HCC induced mice were also decreased compared with the healthy controls. In addition, mouse peritoneal elucidated macrophages (PEMs)-derived M1/M2 macrophages in vitro, as well as human patients of HCC-derived TAMs, were used to examine the transcription levels of ZIPs. Our results showed that both Zip2 and Zip9 were up-regulated in M2-polarized macrophages. Zip2 transcript was also up-regulated M1-polarized macrophages, but Zip9 was slightly down-regulated. TAMs generated from human liver cancer tissues also displayed a decrease in ZIP9 transcription compared to paracarcinoma tissues. To further explore the role of Zip9 in M1/M2 polarization, the siRNA knockdown results revealed that Zip9, but not Zip2, could promote M2 macrophage polarization and impair M1 macrophage polarization. Mechanistically, Zip9 enhances phosphorylated STAT6 to promote M2 macrophage polarization but suppresses the phosphorylation of IκBα/β to inhibit M1 macrophage polarization. Together, our results indicate that ZIP9 may involve in macrophages polarity in HCC development and may be a potent new biomarker for the diagnosis of HCC.

Crosstalk of the Wnt/β-Catenin Signaling Pathway in the Induction of Apoptosis on Cancer Cells

The Wnt/β-catenin signaling pathway plays a major role in cell survival and proliferation, as well as in angiogenesis, migration, invasion, metastasis, and stem cell renewal in various cancer types. However, the modulation (either up- or downregulation) of this pathway can inhibit cell proliferation and apoptosis both through β-catenin-dependent and independent mechanisms, and by crosstalk with other signaling pathways in a wide range of malignant tumors. Existing studies have reported conflicting results, indicating that the Wnt signaling can have both oncogenic and tumor-suppressing roles, depending on the cellular context. This review summarizes the available information on the role of the Wnt/β-catenin pathway and its crosstalk with other signaling pathways in apoptosis induction in cancer cells and presents a modified dual-signal model for the function of β-catenin. Understanding the proapoptotic mechanisms induced by the Wnt/β-catenin pathway could open new therapeutic opportunities.

Serum zinc deficiency in patients after gastrectomy for gastric cancer

PURPOSE

Zinc is an essential dietary component for humans and the second most prevalent trace element; however, serum zinc levels after gastrectomy have not been fully elucidated. This study aimed to evaluate the correlation between clinicopathologic features and serum zinc levels in patients who underwent gastrectomy for gastric cancer.

METHODS

The study enrolled 617 patients who underwent gastrectomy for gastric cancer at the Kochi Medical School. Clinical data were obtained to investigate associations between clinicopathological features, including nutritional indicators and serum zinc levels. Serum zinc deficiency was defined as serum zinc level < 80 μg/dL.

RESULTS

The median zinc level of the 617 patients was 73 μg/dL (range, 31-144 μg/dL), and serum zinc deficiency was present in 68.6% of patients. Median age was significantly higher in the zinc low level group than in the normal group (69 vs. 66 years, P < 0.001). Albumin was significantly lower in the zinc low level group than in the normal group (3.9 vs. 4.2 g/dL, P < 0.001). C-reactive protein level was significantly higher in the zinc low level group than in the normal group (0.12 vs. 0.10 mg/dL, P = 0.014). The median serum zinc level was significantly lower in the patients who received chemotherapy after gastrectomy than in those who were not received chemotherapy (72 vs. 76 μg/dL, P < 0.001). Serum zinc levels showed a significant positive correlation with serum albumin (r = 0.505, P = 0.044). Multivariate analysis showed that serum albumin level was significantly associated with serum zinc level (β = 0.489, P < 0.001).

CONCLUSIONS

Serum zinc deficiency was found in 68.6% of postoperative patients who underwent gastrectomy for gastric cancer, which was highly correlated with serum albumin.

Serum Concentrations of Essential Trace and Toxic Elements in Healthy and Disease-Affected Dogs

Simple Summary

Establishing reference ranges for essential and toxic trace elements in dogs is important to assess health status and to enable assessments of the background levels of toxic element exposure. On the other hand, establishing whether trace element concentrations vary in relation to different pathologies is also important. Serum concentrations of trace elements may be effective diagnostic markers and may help in understanding the pathogenesis of different diseases (and the associated causal relationships).

Abstract

This study was designed (i) to establish reference ranges for the essential trace element and background levels of toxic element exposure in the healthy/normal dog population, and (ii) to evaluate whether trace element concentrations vary in dogs suffering from different pathologies. Blood serum samples were collected from 187 healthy and diseased dogs at the Veterinary Teaching Hospital, Faculty of Veterinary Medicine, University of Santiago de Compostela (northwest Spain). The samples were acid digested, and the concentrations of trace elements (Co, Cr, Cu, Fe, Mn, Mo, Ni, Se and Zn) and toxic elements (As, Cd, Hg and Pb) were determined by inductively coupled plasma-mass spectrometry (ICP-MS). This enabled us to establish reference ranges for the essential trace elements and the level of toxic element exposure in dogs, and to identify several clinical situations associated with variations in trace elements in serum. Relative to concentrations in healthy control dogs, statistically significant differences were observed in the concentrations of Cu (significantly higher in hepatic, inflammatory/infectious and oncological categories), Mo (significantly higher in renal category), Se (significantly lower in gastrointestinal category) and Zn (significantly lower in gastrointestinal, inflammatory/infectious and renal categories). Trace element concentrations can be a cause or consequence of disease, and the study findings indicate that trace element determination in serum provides useful information on the pathogenesis of certain diseases. Further research on the serum concentrations of trace elements, particularly in relation to other biochemical parameters and diagnostic tools, may provide valuable information for the diagnosis of diseases in dogs and the disease prognosis.

Zinc promotes cell apoptosis via activating the Wnt-3a/β-catenin signaling pathway in osteosarcoma

BACKGROUND

The zinc content in the blood and tumor tissues of patients with osteosarcoma and the underlying regulation and molecular mechanism of zinc have not been reported.

METHODS AND RESULTS

This study showed that the zinc content in the blood and tumor tissues of patients with osteosarcoma significantly reduced. CCK-8 and Transwell chamber assays revealed that zinc treatment significantly inhibited the proliferation and invasion abilities of osteosarcoma cells. Western blot analysis indicated that the expression levels of caspase-3 and caspase-9 were significantly increased, suggesting that zinc inhibited the growth and promoted the apoptosis of osteosarcoma cells. In addition, the expression levels of Wnt-3a and β-catenin, the marker proteins of the Wnt/β-catenin signaling pathways, were significantly increased in osteosarcoma cells after zinc intervention, which demonstrated that the pathway was clearly activated. However, the effect of zinc on the apoptosis, proliferation, and invasion abilities of osteosarcoma cells was reversed when the Wnt/β-catenin signaling pathways was inhibited by XAV939 (Wnt antagonist) treatment.

CONCLUSIONS

This study is the first to report the changes in zinc levels in the blood and tumor tissues of patients with osteosarcoma and to preliminarily verify that zinc inhibits the proliferation and invasion and promote the apoptosis of osteosarcoma cells by inducing the Wnt/β-catenin signaling pathway, which ultimately inhibit cancer growth.

Aged Garlic and Cancer: A Systematic Review

Cancer is one of the leading causes of morbidity and mortality worldwide, which increases health-care costs. It has been reported that some dietary components such as aged garlic, one of the garlic preparations with no strong odor and harsh irritating taste, exhibits anticancer effects. This review summarizes the potential beneficial effects of aged garlic on cancer incidences as well as prevention and improvement of factors related to malignancy. Electronic databases, including MEDLINE, Web of Science, the Cochrane Library, and Google Scholar were searched. All study designs which were focused on cancer incidence, or indices related to malignancy as outcomes in human, animal, and human cells studies, and aged garlic and its ingredients as exposures were reviewed in accordance to the items for systematic reviews (PRISMA) guidelines. Initially, 304 articles were identified. Then, 25 articles which met the inclusion criteria were selected. Based on the evaluation, overall quality score of human studies was well. Although there were inconsistent evidence from human studies, results of the animal and laboratory results were mostly consistent. The overall findings may suggest that intakes of aged garlic are inversely associated with cancer. In this regard, the studies have shortcomings. Therefore, more precise investigations will be necessary to decide whether aged garlic consumption is recommendable as a part of cancer prevention or control programs. However, due to anticancer properties of aged garlic, its consumption along with healthy diet may have beneficial effects on cancer.

The Effect of Zinc Supplementationon the Symptoms of Gastroesophageal Reflux Disease; a Randomized Clinical Trial

BACKGROUND Currently, it has been demonstrated that gastroesophageal reflux disease (GERD) is one of the most important disorders of the digestive system and the commixture of regular diet has a significant influence on its incidence, symptoms, and prognosis. The purpose of this study was to evaluate the effect of zinc supplementation, in combination with PPIs(Proton pump inhibitors), on the improvement of GERD symptoms. METHODS In a randomized double blind clinical trial, patients with reflux symptoms, who had obtained Reflux Disease Questionnaire (RDQ) score more than 8, were included and all the demographic features were recorded. Then, using upper gastrointestinal (GI) endoscopy, all the patients were divided into two groups as having non-erosive reflux disorder (NERD),or erosive reflux disorder (ERD). At the next step, based on random block statistical method, we divided the two groups into two subgroups; the drug subgroup [treated with PPIs (40 mg pantoprazole/daily), changing life style, and 220 mgzinc capsules daily] and the placebo subgroup [treated with PPIs, changing life style, and placebo]. After 3 months, we analyzed all data and the RDQ questionnaire was filled out for each patient. This project has been registered in Iranian Registry of Clinical Trials (IRCT) and all data were analyzed using SPSS software version 2. RESULTS A total of 140 patients (81 women and 59 men) with mean age of 42.78±11.5 years were included with 70 patients in each group. The most frequent presentations were heart burn (45.7%), and acid regurgitation (39.3%). The RDQ scores decreased after intervention in both drug (p<0.001) and placebo groups (p<0.001), which were statistically significant. But the difference of RDQ scores between the drug group and placebo group was not statistically significant (p=0.086). CONCLUSION Zinc supplementation cannot improve the severity of GERD.