In vivo electroporation restores the low effectiveness of DNA vaccination against HER-2/neu in aging.

Experimental evidence has been provided that cancer vaccines are less effective at older age than in young adults. In this study, we evaluated the possibility to recover the low effectiveness of DNA immunization against HER-2/neu increasing plasmid uptake by cells from old mice through electroporation with the aim to enhance the activation of specific immune responses. Young and old Balb/c mice received two immunizations with a pCMV-ECDTM DNA plasmid using plasmid intramuscular injection followed by electroporation (IM + E) or plasmid intramuscular injection alone (IM), and successively, they were challenged with syngeneic HER-2/neu overexpressing TUBO cells. Young mice were completely protected whereas less than 60% protection was observed in old mice after IM immunization. IM + E immunization completely protected old mice against a TUBO cell challenge. The protection was associated with increased transgene expression in the site of immunization and with the induction of both humoral and cell-mediated immunity in old mice. We conclude that the effectiveness of anticancer DNA vaccination in old ages may be improved increasing plasmid uptake and transgene expression through electroporation, suggesting the relevant role of the first steps of the immunization process in the success of cancer vaccines at older age.

Speciation of trace elements in human serum by micro anion exchange chromatography coupled with inductively coupled plasma mass spectrometry.

Speciation analysis of essential trace elements in human serum provides important information on nutritional status and homeostatic mechanisms regulating transport processes, acute phase reactions, and protection against oxidative damage. Anion exchange high-performance liquid chromatography (HPLC) combined with inductively coupled plasma mass spectrometry (ICP-MS) has proved to be a useful tool in speciation. Here we describe a fast method that can be applied to carry out the speciation of Fe, Cu, Zn, and Se in as little as 1 microl [corrected] of serum. The method employs monolithic anion exchange micro columns installed on a tandem HPLC system coupled on-line with an ICP-MS detector. The chromatographic separation is similar to those reported previously but with considerable gain in terms of time and sample requirement. Reproducibility is acceptable for most species. Using our method, we were able to find species-specific differences between different commercially available trace element reference materials. Because the method chosen to collect blood might interfere with speciation, the proposed methodology was used to compare heparinized plasma, ethylenediaminetetraacetic acid (EDTA) plasma, and serum from adult healthy volunteers. As expected, EDTA strongly affects speciation analysis (especially for Fe and Zn), whereas changes due to the use of lithium-heparin (Li-He) as anticoagulant appear to be minimized.

Diet (zinc)-gene interaction related to inflammatory/immune response in ageing: possible link with frailty syndrome?

The pivotal role played by zinc-gene interaction in affecting the inflammatory response mediated by IL-6 in ageing, successful ageing (nonagenarians) and the most common age-related diseases is now recognized. Contradictory data emerging from association studies of IL-6 polymorphisms with longevity and chronic age-related diseases seem to arise from the interaction of this inflammatory pathway with dietary habits. Similar conclusions are expected to arise from association studies with the frailty syndrome. Some polymorphisms of genes related to vitamin B12 availability have been already found to be associated with frailty suggesting a possible link among diet-gene interaction and frailty in old age. Other studies in this field are urgently required because of their high potential for suggesting strategies in the care and prevention of frailty in ageing through dietary interventions, in which nutrient zinc may play a pivotal role taking into account that the high copper to zinc ratio is a significant index of the mortality in older people.

Plasma copper/zinc ratio: an inflammatory/nutritional biomarker as predictor of all-cause mortality in elderly population.

Associations have been reported between plasma Cu and Zn levels and the incidence of the most important age-related diseases. Previously proposed methods of using plasma Cu/Zn as a predictor of all-cause mortality have been derived from populations in which old and very old subjects were underrepresented. The purpose of this paper is to estimate the usefulness of plasma Cu/Zn as a sensitive biomarker of harmful inflammatory or nutritional changes in the elderly and its incremental prognostic utility as a predictor of all-cause mortality in a functionally independent elderly Italian cohort. The association between plasma Cu/Zn and inflammatory (CRP, ESR, IL-6) or nutritional (albumin, BMI) markers was studied in 498 elderly subjects. Blood samples were taken from 164 healthy 20- to 60-year-old volunteer controls. A 3.5 years prospective follow-up study of mortality by age-related diseases was performed in n = 218 over 70-year-olds. Plasma Cu/Zn ratio was associated with all the inflammatory markers studied, as well as with serum albumin, and predicted 3.5 years mortality in subjects over 70. Plasma Cu/Zn was higher in women than men and increased with advancing age. Subjects with stable cardiovascular disease (CVD) displayed higher plasma Cu/Zn than those without, due mainly to increased plasma Cu. However, most of the age-related changes of Cu/Zn resulted from a progressive decline of plasma Zn. Cu/Zn ratio may be considered an important clinical inflammatory-nutritional biomarker as well as a significant predictor of all-cause mortality in over 70-year-olds.

In vivo effect of alpha-bisabolol, a nontoxic sesquiterpene alcohol, on the induction of spontaneous mammary tumors in HER-2/neu transgenic mice.

Breast cancer represents the most commonly diagnosed invasive malignancy in pre- and postmenopausal women in both developed and underdeveloped countries. Taking into account that treatment options, including surgery, have not been able to deal with the growing incidence of breast malignancy, it is required to develop mechanism-based novel agents for its prevention. Wide interest in some natural compounds as antiinflammatory agents and as alternative to the traditional medicines is increasing because they do not provoke any adverse effects and are effective in multiple organs, alpha-Bisabolol (BISA), a small oily sesquiterpene alcohol, was reported as chemopreventive agent in induced rat mammary carcinogenesis. The aim of the present study is to investigate the role played by two doses of BISA (via intramammary infusion) on the induction and development of mammary tumor in HER-2/neu transgenic mice as well as the BISA effect after tumor surgical resection. The main data show that (a) optimal dosage of BISA is 10 mg/mouse rather than 3.6 mg/mouse with no adverse effects (e.g., alopecia); (b) the number of the palpable tumor masses decreases in mice treated with 10 mg/mouse of BISA; (c) mice after surgical resection of the primary tumor and treatment with BISA (10 mg) are free from tumor for more weeks, after the surgical treatment; (d) using array analysis, some genes implicated in carcinogenesis mechanisms (NF-kappaBia, Map2k, Mapkl4, and HER2/ neu), angiogenesis process (Fgf), and inhibition of apoptosis (Birc5) are differently regulated after BISA treatment, with a downregulation of the HER2/neu as well as of Fgf and Birc5 genes; (e) the NK cell cytotoxicity increases in tumor-treated mice, especially after the removal of the first tumor mass. Such effectiveness could be important to achieve goals for a possible combination of BISA to conventional therapies in breast cancer and to tumor surgical removal (adjuvant therapy), as suggested for other sesquiterpene analogs.

Effect of the silybin-phosphatidylcholine complex (IdB 1016) on the development of mammary tumors in HER-2/neu transgenic mice.

Silybin, a main component of the milk thistle of Silybum marianum, has been reported to possess anticancer activity. We investigated the effects of IdB 1016, a complex of silybin with phosphatidylcholine, on the development of mammary tumors appearing spontaneously in HER-2/neu transgenic mice. The mechanisms involved in the antitumor effect of IdB 1016 were evaluated by studying the apoptosis, senescent-like growth arrest, intratumoral leukocyte infiltrate, and the expression of HER-2/neu and p53 in tumoral mammary glands from transgenic mice and in human breast SKBR3 tumor cells. The administration of IdB 1016 delayed the development of spontaneous mammary tumors, reduced the number and size of mammary tumor masses, and diminished lung metastasization in HER-2/neu transgenic mice. In tumoral mammary glands from IdB 1016-treated mice, a down-regulation of HER-2/neu gene expression was associated with an increased senescent-like growth arrest of tumor cells, and an increased infiltrate of neutrophils, CD4, and CD8 T cells. Both senescent-like growth arrest and apoptosis were significantly increased and were associated with a reduced p185(HER-2/neu) protein and an increased p53 mRNA in SKBR3 in vitro treated with IdB 1016 in comparison with control cells. The results show the antitumor effect of IdB 1016 in the development of spontaneous mammary tumors in HER-2/neu transgenic mice. The effect of IdB 1016 might be related to the down-regulation of HER-2/neu expression and the induction of senescent-like growth arrest and apoptosis through a p53-mediated pathway in tumor cells.

Zinc deficiency and IL-6 -174G/C polymorphism in old people from different European countries: effect of zinc supplementation. ZINCAGE study.

IL-6 SNP at position -174 is associated with age-related diseases characterized by an impaired Zn status. This polymorphism seems also relevant in regulating the expression of proteins, such as Metallothioneins (MT), involved in the modulation of Zn homeostasis. Since high IL-6 levels in elderly induce hypozinchemia, the IL-6-174 SNP may be useful to identify old subjects who are at risk for Zn deficiency. The objectives of this study are: (1) to choose old subjects who effectively need Zn supplementation and (2) to study the effect of Zn supplementation on Zn, immune and psychological status in genetically selected subjects. For this purpose, a baseline study comprising 895 healthy old subjects recruited in Central-Northern and Southern European Countries was carried out by evaluating their dietary intake, psychological and immune parameters as well as their Zn status. A Zn supplementation trial was performed in 110 old subjects selected on the basis of their plasma Zn levels and IL-6 SNP. After correcting for age and Zn intake, C- carriers displayed higher MT and lower levels of several parameters related to zinc status (plasma Zn, erythrocyte Zn and NO-induced release of Zn in PBMC) than C+ carriers. Better NK cell cytotoxicity and psychological functions (PSS, MMSE) were also found in C+ than C- carriers strictly related to the zinc status. However, independently by the polymorphism, all subjects with plasma zinc < or = 10.5microM showed the worst immune response and psychological functions. Supplementation was carried out in C+ and C- carriers with stable low plasma zinc levels ( < or =10.5microM at baseline and at 1 year follow-up) and in C- carriers with unstable plasma zinc (< or =10.5microM at baseline and >10.5microM at 1 year follow-up). C+ carriers with plasma zinc >10.5microM were not supplemented because showing the best immune and psychological conditions. After 48+/-2 days of supplementation with 10mg/day of Zn-aspartate, the NO-induced release of Zn, erythrocyte Zn and NK cell cytotoxicity increased in all groups selected for supplementation, including C- with unstable plasma zinc. In conclusion, the sole assessment of plasma Zn level is not reliable to exclude C- carriers from Zn supplementation. A possible explanation for the conflicting data on the identification of IL-6-174G as a "risk allele" based on different dietary intake in the studied population is also suggested.

A novel Zip2 Gln/Arg/Leu codon 2 polymorphism is associated with carotid artery disease in aging.

Zinc deficiency represents a risk factor for carotid stenosis (CS) development. In mammals, members of the ZIP family regulate zinc uptake, and hZip2 is a human zinc importer upregulated by zinc depletion. The purpose of this study was to investigate the association of a novel Zip2 Gln/Arg/Leu codon 2 polymorphism with CS, analyzing 250 CS patients and 259 elderly controls. CS patients showed an increased GG genotype frequency (60% vs. 47.5%), and a reduced TT frequency (6% vs. 10%) (p < 0.05 by chi(2) test). In conclusion, Zip2 Gln/Arg/Leu polymorphism plays a role in the susceptibility to carotid artery disease.

Metallothionein downregulation in very old age: a phenomenon associated with cellular senescence?

It is known that metallothionein (MT) mRNA expression first increases with age, but then decreases again in the very elderly. Here we report that MT protein levels also decrease in very old age, and that this is independent of dietary zinc intake. Age-related changes of MT, as well as alterations of zinc homeostasis (intracellular labile zinc and NO-induced zinc release), occur both in human PBMCs ex vivo and also in CD4+ T cell clones progressing through their finite life span in vitro. These results suggest that phenomena observed in very old people can be at least partially attributed to diminished cell proliferation.

HER2/neu DNA vaccination for breast tumors.

Several studies of DNA vaccination against HER2/neu showed the effectiveness of immunization protocols in models of transplantable or spontaneous tumors. The DNA delivery system plays a crucial role in the success of DNA vaccination. In particular, our studies of DNA vaccination against HER2/neu tumor antigen showed that intramuscular injection of the vaccine followed by electroporation elicits an optimal protection against the development of spontaneous HER2/neu- tumors occurring in transgenic mice.

Survival study of metallothionein-1 transgenic mice and respective controls (C57BL/6J): influence of a zinc-enriched environment.

The role of metallothioneins (MTs) in aging is not completely understood. Several studies have shown evidence that these proteins could represent a defense system against oxidative damage, but survival studies on mice overexpressing MTs are poor. Here we describe a survival study performed on old MT-1-overexpressing mice (MT-TG) and their respective controls (C57BL/6J) fed a standard or zinc (Zn)-supplemented diet. MT-TG mice had significantly increased survival compared with control. Zn supplementation affects the survival curves of MT-TG and C57BL/6J mice differently. This study poses the basis for intervention based on gene therapy with MTs to enhance the health span of laboratory mice.

Association of MT1A haplotype with cardiovascular disease and antioxidant enzyme defense in elderly Greek population: comparison with an Italian cohort.

Metallothioneins (MT), the antioxidant zinc-binding proteins, seem to mediate cardioprotection. It has been postulated that zinc homeostasis and MT function may be altered, as a consequence of oxidative stress, in cardiovascular disease (CVD), with a potential implication of MT genetic polymorphisms. The present study explores the role of +647A/C and +1245A/G MT1A polymorphisms on the susceptibility to CVD, zinc status and enzyme antioxidant activity, in the Greek and Italian populations. The country selection was based on the lower zinc status and the reduced zinc dietary intake in Greece than in Italy despite the similar Mediterranean dietary pattern. A total of 464 old, healthy control subjects and 369 old CVD patients more than 70 years of age were studied. Logistic regression model indicated that +1245 MT1A G+ genotype significantly increased the risk of CVD in Greece (34.4% vs. 23.2%; odds ratio=1.88, 95% confidence interval=1.14-3.08; P=.013) but not in Italy. Haplotype analysis showed an increment of CG haplotype frequency in CVD Greek patients (17.4% vs. 10.6%, P<.05). Differential country-related frequency distribution was also recorded. Applying a multivariate regression model, +647/+1245 MT1A haplotype was associated with a modulation of enzyme antioxidant activities in both countries. Decreased plasma zinc and reduced intracellular Zn release, as well as increased enzyme antioxidant activity, were more apparent in Greek healthy donors than in Italy. In conclusion, +1245 MT1A polymorphism and +647/+1245 MT1A haplotype are implicated in CVD in Greece but not in Italy, suggesting a role of gene-diet interaction in the disease predisposition.

Distinctive modulation of inflammatory and metabolic parameters in relation to zinc nutritional status in adult overweight/obese subjects.

Overweight and obesity are associated with low grade of inflammation and chronic inflammatory response characterized by abnormal production and activation of some pro-inflammatory signalling pathways. Taking into account that obesity is the direct result of an imbalance between energy intake and energy expenditure, the nutritional factors in the diet, with particular focus on zinc, may play a pivotal role in the development of obesity-associated comorbidities. Considering the potential interactions among zinc nutritional status, inflammation, overweight/obesity and insulin secretion, the aim of the present work was to clarify the influence of zinc dietary intake on some metabolic, inflammatory and zinc status parameters in adult overweight/obese subjects. We found a close interrelationship between nutritional zinc and obesity. In particular, subjects with a lower zinc dietary intake display a deeper inflammatory status, general impairment of the zinc status, an altered lipid profile and increased insulin production with respect to obese subjects with normal zinc dietary intake. Moreover, in the presence of low dietary zinc intake, the obese subjects are less capable to respond to oxidative stress and to inflammation leading to the development of obesity or to a worsening of already preexisting obesity status. In conclusion, a possible zinc supplementation in obese subjects with a deeper inflammatory status and more altered zinc profile may be suggested in order to limit or reduce the inflammation, taking also into account that zinc supplementation normalizes "inflammaging" as well as zinc profile leading to a correct intra- and extracellular zinc homeostasis.

Accumulation of cells with short telomeres is associated with impaired zinc homeostasis and inflammation in old hypertensive participants.

Critical shortening of telomeres, likely associated with a considerable increase of senescent cells, can be observed in PBMC of individuals aged 80 and older. We investigated the relationship between critical telomere shortening and zinc status in healthy or hypertensive participants with or without cardiovascular disease in old and very old participants. Telomere shortening and accumulation of cells with short telomeres (percent of cells with short telomeres) in advancing age was evident in patients and healthy controls, but exacerbated in those patients aged 80 and older. Moreover, in very old patients, the accumulation of % CST may impair intracellular zinc homeostasis and metallothioneins expression, which itself is linked to an increased number of inflammatory agents, thereby suggesting the existence of a possible causal relationship between % CST and zinc homeostasis. The determination of % CST could be a more reliable means than the simple measure of telomere length as fundamental parameter in ageing to determine whether individuals are still able to respond to stress.

l-Arginine normalizes NOS activity and zinc-MT homeostasis in the kidney of mice chronically exposed to inorganic mercury.

Inorganic mercury (HgCl2) exposure provokes damage in many organs, especially kidney. Inducible nitric oxide synthase (iNOS) expression, total NOS activity and the profiles of zinc (Zn), copper (Cu) and Hg as well as their distribution when bound to specific intracellular proteins, including metallothioneins (MT), were studied during HgCl2 exposure and after l-arginine treatment in C57BL/6 mouse kidney. HgCl2 exposure modulates differently iNOS expression and NOS activity, increasing iNOS expression but, conversely, decreasing total NOS activity in the mouse kidney. Moreover, during Hg exposure an increased MT production occurs. The kidney damage leads to a loss of urinary proteins, increased plasma creatinine and high Zn mobilization with consequent increased urinary Zn excretion. l-arginine treatment recovers NOS activity and induces a normalization of MT induction, plasma creatinine values and urinary proteins excretion, suggesting that l-arginine may limit kidney damages by Hg exposure.

Evaluation of different plasmid DNA delivery systems for immunization against HER2/neu in a transgenic murine model of mammary carcinoma.

Studies of DNA vaccination against HER2/neu showed the effectiveness of immunization protocols in models of transplantable or spontaneous tumors; scarce information, however, has been provided to identify the procedure of DNA administration that more effectively contributes to the activation of immune system against spontaneously arising HER2/neu-positive tumors. We compared the effectiveness of different procedures of DNA vaccine delivery (intradermic injection (ID), gene gun (GG) delivery and intramuscular injection (IM) alone or with electroporation) in a murine transgenic model of mammary carcinoma overexpressing HER2/neu. We highlighted the role of DNA delivery system in the success of DNA vaccination showing that, among the analysed methods, intramuscular injection of the vaccine, particularly when associated to electroporation, elicits a better protection against HER2/neu spontaneous tumor development inducing antibody and cell-mediated immune responsiveness against HER2/neu and a Th1 polarization of the immune response.