Combination of Fish Oil and Selenium Enhances Anticancer Efficacy and Targets Multiple Signaling Pathways in Anti-VEGF Agent Treated-TNBC Tumor-Bearing Mice.

Fish oil (FO) and selenium (Se) possess antiangiogenic potential in malignant tumors. This study aimed to determine whether combination of FO and Se enhanced treatment efficacy of low-dose antiangiogenic agent Avastin (bevacizumab) in a dose-dependent manner and targeted multiple signaling pathways in triple-negative breast cancer (TNBC)-bearing mice. Randomized into five groups, mice received treatment with either physiological saline (control), Avastin alone, or Avastin in combination with low, medium, and high doses of FO/Se. The target signaling molecules for anticancer were determined either by measuring protein or mRNA expression. Avastin-treated mice receiving FO/Se showed lower tumor growth and metastasis than did mice treated with Avastin alone. Combination-treated mice exhibited lower expressions in multiple proangiogenic (growth) factors and their membrane receptors, and altered cytoplasmic signaling molecules (PI3K-PTEN-AKT-TSC-mTOR-p70S6K-4EBP1, Ras-Raf-MEK-ERK, c-Src-JAK2-STAT3-TMEPAI-Smad, LKB1-AMPK, and GSK3ß/ß-catenin). Dose-dependent inhibition of down-stream targets including epithelial-to-mesenchymal transition transcription factors, nuclear cyclin and cyclin-dependent kinases, cancer stem cell markers, heat shock protein (HSP-90), hypoxia-inducible factors (HIF-1α/-2α), matrix metalloprotease (MMP-9), and increased apoptosis were observed. These results suggest that combination treatment with FO and Se increases the therapeutic efficacy of Avastin against TNBC in a dose-dependent manner through multiple signaling pathways in membrane, cytoplasmic, and nucleic targets.

Nutritional supplements in combination with chemotherapy or targeted therapy reduces tumor progression in mice bearing triple-negative breast cancer.

The potential anti-cancer properties of selenium (Se) and eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) have been documented. However, few studies have been conducted examining anti-tumor effects of nutritional supplements (NS) containing Se and EPA/DHA in combination with anti-cancer agents, such as taxol (Tax), adriamycin (Adr), and avastin (Ava). Compared with triple-negative breast cancer (TNBC)-bearing positive control (TB) mice, a low dose of Tax, Adr, and Ava decreased tumor size and the incidence of metastasis in TB-Tax, TB-Adr, and TB-Ava groups. Combination treatment with anti-cancer agent and NS (2.7 µg Se and 5.1 mg EPA/3.7 mg DHA/g) induced additional decreases in TB-Tax-NS, TB-Adr-NS, and TB-Ava-NS groups. Th1-associated cytokines were increased, and Th2-type cytokines were decreased significantly in TB mice with combination treatment than that of anti-cancer agent treatment alone. Combination treatment with anti-cancer agents and NS has also been shown to further increased tumor malondialdehyde (MDA) levels, lowered hypoxia-inducible factor (HIF)-1α, angiogenic markers (vascular endothelial growth factor [VEGF] and CD31) and metastatic potential, as well as reduced heat shock proteins, receptor tyrosine kinase AXL, and surface markers of cancer stem cells, and increased apoptotic proteins. For immune checkpoint molecules, combination treatment was associated with a greater decrease in programmed cell death ligand-1 (PD-L1) in both tumors and mammary glands, but PD-1 level in primary tumors was increased. Our results suggest that combination treatment with low-dose anti-cancer agents (Tax, Adr, and Ava) and oral supplementation of Se/ EPA/DHA significantly decreased tumor growth and metastatic progression in TNBC mice through multiple anti-tumor mechanisms.

Altered Mineral Metabolism and Disequilibrium Between Calcification Promoters and Inhibitors in Chronic Hemodialysis Patients.

Patients undergoing long-term hemodialysis (HD) are known to have abnormal blood concentrations of antioxidant minerals; concurrent oxidative stress can contribute to increased vascular calcification. This study aims to evaluate the associations between circulating antioxidant minerals and clinical biomarkers of vascular calcification in HD patients. Blood biochemical parameters, antioxidant minerals (selenium (Se), zinc (Zn), copper (Cu), and magnesium (Mg)), and several promoters and inhibitors of calcification (matrix Gla protein (MGP), fibroblast growth factor-23 (FGF-23), matrix metalloproteinases (MMP-2 and -9), and tissue inhibitors of metalloproteinase (TIMP-1 and -2)) were determined in HD patients (n = 62) and age- and sex-matched healthy individuals (n = 30). Compared with healthy subjects, HD patients had significantly lower plasma concentrations of Se and Zn, increased Cu and Mg, and higher levels of oxidative stress and inflammatory markers (Cu/Zn ratios, malondialdehyde (MDA), advanced glycation end products (AGEs), and C-reactive protein (CRP)). We observed that HD patients had significantly lower concentrations of MGP and higher levels of FGF-23, MMP-2 and -9, TIMP-1 and -2, and MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios. We also observed significant relationships between the concentrations of these minerals and calcification biomarkers in HD patients. These results suggest that changes in the homeostasis of antioxidant minerals (Se, Zn, Cu, and Mg) may contribute to the effects of oxidative stress and inflammatory status, thereby participating in the mechanism for accelerated vascular calcification in patients undergoing long-term HD.

H2B mono-ubiquitylation facilitates fork stalling and recovery during replication stress by coordinating Rad53 activation and chromatin assembly.

The influence of mono-ubiquitylation of histone H2B (H2Bub) on transcription via nucleosome reassembly has been widely documented. Recently, it has also been shown that H2Bub promotes recovery from replication stress; however, the underling molecular mechanism remains unclear. Here, we show that H2B ubiquitylation coordinates activation of the intra-S replication checkpoint and chromatin re-assembly, in order to limit fork progression and DNA damage in the presence of replication stress. In particular, we show that the absence of H2Bub affects replication dynamics (enhanced fork progression and reduced origin firing), leading to γH2A accumulation and increased hydroxyurea sensitivity. Further genetic analysis indicates a role for H2Bub in transducing Rad53 phosphorylation. Concomitantly, we found that a change in replication dynamics is not due to a change in dNTP level, but is mediated by reduced Rad53 activation and destabilization of the RecQ helicase Sgs1 at the fork. Furthermore, we demonstrate that H2Bub facilitates the dissociation of the histone chaperone Asf1 from Rad53, and nucleosome reassembly behind the fork is compromised in cells lacking H2Bub. Taken together, these results indicate that the regulation of H2B ubiquitylation is a key event in the maintenance of genome stability, through coordination of intra-S checkpoint activation, chromatin assembly and replication fork progression.

Heme oxygenase-1 induction by the ROS-JNK pathway plays a role in aluminum-induced anemia.

Aluminum (Al) overload is correlated with hypochromic anemia. It is possible that Al impedes heme biosynthesis and degradation by affecting the activity of biosynthetic enzymes. However, the molecular mechanisms by which Al affects these enzymes are unknown. Here, we show that long-term exposure of Sprague-Dawley rats to Al decreased hemoglobin concentration and the hematocrit level. In addition, the activity of aminolevulinic acid dehydratase (ALA-D) in rat liver was reduced, but heme oxygenase (HO) activity was enhanced, suggesting an impairment of heme homeostasis. The increase in HO activity was due to up-regulation of mRNA and protein of an inducible HO isozyme, HO-1. Furthermore, we found that reactive oxygen species (ROS)-mediated activation of c-Jun N-terminal kinase (JNK) was critical for HO-1 induction by Al, because ROS scavengers and JNK inhibitors abrogated enhancement of HO-1 by Al in rat hepatocytes. Thus, Al enhances HO-1 expression through the ROS-JNK pathway, which may enhance HO activity and accelerate degradation of heme, leading to hypochromic anemia.

Zinc supplementation alters plasma aluminum and selenium status of patients undergoing dialysis: a pilot study.

End stage renal disease patients undergoing long-term dialysis are at risk for abnormal concentrations of certain essential and non-essential trace metals and high oxidative stress. We evaluated the effects of zinc (Zn) supplementation on plasma aluminum (Al) and selenium (Se) concentrations and oxidative stress in chronic dialysis patients. Zn-deficient patients receiving continuous ambulatory peritoneal dialysis or hemodialysis were divided into two groups according to plasma Al concentrations (HA group, Al > 50 g/L; and MA group, Al > 30 to ≤ 50 g/L). All patients received daily oral Zn supplements for two months. Age- and gender-matched healthy individuals did not receive Zn supplement. Clinical variables were assessed before, at one month, and after the supplementation period. Compared with healthy subjects, patients had significantly lower baseline plasma Se concentrations and higher oxidative stress status. After two-month Zn treatment, these patients had higher plasma Zn and Se concentrations, reduced plasma Al concentrations and oxidative stress. Furthermore, increased plasma Zn concentrations were related to the concentrations of Al, Se, oxidative product malondialdehyde (MDA), and antioxidant enzyme superoxide dismutase activities. In conclusion, Zn supplementation ameliorates abnormally high plasma Al concentrations and oxidative stress and improves Se status in long-term dialysis patients.

The relationship of plasma aluminum to oxidant-antioxidant and inflammation status in asthma patients.

Aluminum (Al) is a non-essential mineral which human beings are exposed to on day-to-day life. The purpose of this study was to assess the concentrations of plasma Al and the relationship of those levels with risk factors for asthma. In total, 27 allergic asthmatics and 30 healthy volunteers were enrolled. Plasma Al and selected blood parameters were measured, and a pulmonary function test was performed. Higher Al concentrations were found in the asthmatics than the healthy controls. Increased immunoglobulin E, high-sensitivity C-reactive protein, lipid peroxidation products, and pro-inflammatory cytokines (tumor necrosis factor-α and interleukin [IL]-4) were observed, but IL-10 and overall antioxidant and enzyme activities were lower. Associations between oxidative-antioxidant status and inflammatory markers with plasma Al levels in asthmatics were noted. Al status was also linked to cytokine concentrations and pulmonary function. In conclusion, abnormal Al distribution may further precipitate oxidative stress and inflammation, alter Th1/Th2 lymphocyte balance, and therefore contribute to the development of asthma.

Alterations in trace elements and oxidative stress in uremic patients with dementia.

The present study was conducted to compare the trace elements and oxidative status between uremic patients with and without dementia. Chronic hemodialysis patients with dementia (n = 20) and without dementia (n = 25), and age-matched healthy volunteers (n = 20) were enrolled. The nutritional status, blood levels of trace elements aluminum (Al), zinc (Zn), copper (Cu), magnesium (Mg) and iron (Fe), malondialdehyde (MDA), and protein carbonyl production, antioxidant enzymes glutathione peroxidase (GPx), and glutathione reductase (GR) activities were measured. No significant difference in nutritional status or clinical characteristics was observed between nondementia and dementia patients. However, uremic patients with dementia have significantly higher Al, Cu, and Mg and lower Zn concentrations, as well as increased Cu/Zn ratio in comparison to nondementia patients. There were statistically significant increased MDA and carbonyl production and decreased GPx and GR activities in dementia patients. Furthermore, the significant associations of Al, Mg, and Cu/Zn ratio with oxidative status in patients with dementia were noted. The dementia may initially worsen with abnormal metabolism of trace elements and oxidative stress occurrence. Our results suggest that abnormalities in trace element levels are associated with oxidative stress and may be a major risk factor in the dementia development of uremic patients.

Aluminum accumulation induced testicular oxidative stress and altered selenium metabolism in mice.

Present work was carried out to investigate how testicular selenium (Se) metabolisms respond to oxidative stress induced by aluminum (Al). Mice were intraperitoneally exposed to 0, 7, or 35mg Al/kg/d for 14 days (CNL, LAL and HAL groups). Al administration significantly increased Al, reactive oxygen radical and malondialdehyde (MDA) levels, as well as decreased glutathione peroxidase (GPx) and glutathione reductase (GR) activities in serum and testes. The serum concentrations of Se were remarkably lower at LAL and HAL groups compared to the controls, whereas the testicular Se levels significantly reduced only in the HAL group. In addition, RT-PCR analysis revealed an increased testicular selenoprotein P (SelP) expression by Al treatment. Western blot analysis showed increased levels of SelP protein expression in the LAL group, but the expression levels were significantly reduced in HAL group. It was suggested that altered metabolism of Se, further stimulated testicular SelP transcription that may compensate for the loss of SelP protein resulted from Al-induced oxidative damage.

Blood micronutrient, oxidative stress, and viral load in patients with chronic hepatitis C.

AIM: To assess the extent of micronutrient and oxidative stress in blood and to examine their linkages with viral loads in chronic hepatitis C patients. METHODS: Hepatitis C virus (HCV)-RNA levels were quantified in the serum from 37 previously untreated patients with chronic hepatitis C. The plasma and erythrocyte micronutrients (zinc, selenium, copper, and iron) were estimated, and malondialdehyde (MDA) contents were determined as a marker to detect oxidative stress. Antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione reductase (GR) activities in blood were also measured. The control group contained 31 healthy volunteers. RESULTS: The contents of zinc (Zn), and selenium (Se) in plasma and erythrocytes were significantly lower in hepatitis C patients than in the controls. On the contrary, copper (Cu) levels were significantly higher. Furthermore, plasma and erythrocyte MDA levels, and the SOD and GR activities in erythrocytes significantly increased in hepatitis C patients compared to the controls. However, the plasma GPX activity in patients was markedly lower. Plasma Se (r = -0.730, P<0.05), Cu (r = 0.635), and GPX (r = -0.675) demonstrated correlations with HCV-RNA loads. Significant correlation coefficients were also observed between HCV-RNA levels and erythrocyte Zn (r = -0.403), Se (r = -0.544), Cu (r = 0.701) and MDA (r = 0.629) and GR (r = 0.441). CONCLUSION: The levels of Zn, Se, Cu, and oxidative stress (MDA), as well as related anti-oxidative enzymes (GR and GPX) in blood have important impact on the viral factors in chronic hepatitis C. The distribution of these parameters might be significant biomarkers for HCV.

The effect of zinc supplementation on the treatment of chronic hepatitis C patients with interferon and ribavirin.

OBJECTIVES: To evaluate the effects of zinc supplementation on serum zinc and copper levels, and the severity of adverse reactions and virologic responses in chronic hepatitis C patients undergoing interferon (IFN)/ribavirin therapy. DESIGN AND METHODS: Forty subjects were randomly assigned to receive IFN-alpha-2a/ribavirin with or without zinc gluconate for 24 weeks, then a period of 6 months for follow-up. Twenty healthy controls were also enrolled in the study. Blood samples were collected at different time points during therapy and at 6 months after the completion of therapy and were analyzed for zinc and copper levels. The adverse reactions and the virologic responses were also examined accordingly. RESULTS: Serum zinc levels were significantly lower in chronic hepatitis C patients than in healthy controls and further depressed by IFN/ribavirin treatment. However, serum zinc levels in patients were remediable by zinc supplements. No apparent difference was seen in virologic responses between subjects with or without zinc supplements, but certain adverse side effects associated with the zinc therapy were significantly decreased. CONCLUSIONS: Zinc supplementation may be a complementary therapy in chronic hepatitis C patients to increase the tolerance to IFN-alpha-2a and ribavirin.

Distribution patterns of trace metals and of lipid peroxidation in plasma and erythrocytes of rat exposed to aluminum.

Significant decreases of the hematocrit, hemoglobin, and plasma iron levels were observed in rats receiving daily intraperitoneal injections of aluminum at a dose of 27 mg Al/kg body wt for 3 wk, as compared to untreated controls. The activity of alkaline phosphatase was also significantly lower in the treated animals as a result of the accumulation of aluminum in the liver (p<0.05). Following aluminum administration, the plasma concentrations of aluminum and copper were also significantly increased, whereas the plasma zinc levels and oxidative stress measured through thiobarbituric acid reaction products showed nonsignificant differences between the two groups (p>0.05). The erythrocyte concentrations of aluminum, copper, zinc, and iron and of superoxide dismutase activity were found to be significantly higher in the study group as compared to controls. The treated animals also showed evidence of higher oxidative stress in comparison to controls. These results suggest that erythrocyte aluminum accumulation could result in abnormal trace element homeostasis and increasing oxidative stress, which might be a mechanism of aluminum-induced anemia.