Zinc as an anti-tumor agent in prostate cancer and in other cancers

Elements in trace amount with a significant role in human physiology: a tumor pathophysiological and diagnostic aspects

Cancer has a devastating impact globally regardless of gender, age, and community, which continues its severity to the population due to the lack of efficient strategy for the cancer diagnosis and treatment. According to the World Health Organisation report, one out of six people dies due to this deadly cancer and we need effective strategies to regulate it. In this context, trace element has a very hidden and unexplored role and require more attention from investigators. The variation in concentration of trace elements was observed during comparative studies on a cancer patient and a healthy person making them an effective target for cancer regulation. The percentage of trace elements present in the human body depends on environmental exposure, food habits, and habitats and could be instrumental in the early diagnosis of cancer. In this review, we have conducted inclusive analytics on trace elements associated with the various types of cancers and explored the several methods involved in their analysis. Further, intricacies in the correlation of trace elements with prominent cancers like prostate cancer, breast cancer, and leukaemia are represented in this review. This comprehensive information on trace elements proposes their role during cancer and as biomarkers in cancer diagnosis.

Emerging Perspectives in Zinc Transporter Research in Prostate Cancer: An Updated Review

Dysregulation of zinc and zinc transporters families has been associated with the genesis and progression of prostate cancer. The prostate epithelium utilizes two types of zinc transporters, the ZIP (Zrt-, Irt-related Protein) and the ZnTs (Zinc Transporter), to transport zinc from the blood plasma to the gland lumen. ZIP transporters uptake zinc from extracellular space and organelle lumen, while ZnT transporters release zinc outside the cells or to organelle lumen. In prostate cancer, a commonly observed low zinc concentration in prostate tissue has been correlated with downregulations of certain ZIPs (e.g., ZIP1, ZIP2, ZIP3, ZIP14) and upregulations of specific ZnTs (e.g., ZnT1, ZnT9, ZnT10). These alterations may enable cancer cells to adapt to toxic high zinc levels. While zinc supplementation has been suggested as a potential therapy for this type of cancer, studies have yielded inconsistent results because some trials have indicated that zinc supplementation could exacerbate cancer risk. The reason for this discrepancy remains unclear, but given the high molecular and genetic variability present in prostate tumors, it is plausible that some zinc transporters-comprising 14 ZIP and 10 ZnT members-could be dysregulated in others patterns that promote cancer. From this perspective, this review highlights novel dysregulation, such as ZIP-Up/ZnT-Down, observed in prostate cancer cell lines for ZIP4, ZIP8, ZnT2, ZnT4, ZnT5, etc. Additionally, an in silico analysis of an available microarray from mouse models of prostate cancer (Nkx3.1;Pten) predicts similar dysregulation pattern for ZIP4, ZIP8, and ZnT2, which appear in early stages of prostate cancer progression. Furthermore, similar dysregulation patterns are supported by an in silico analysis of RNA-seq data from human cancer tumors available in cBioPortal. We discuss how these dysregulations of zinc transporters could impact zinc supplementation trials, particularly focusing on how the ZIP-Up/ZnT-Down dysregulation through various mechanisms might promote prostate cancer progression.

Cuproptosis in cancer: biological implications and therapeutic opportunities

Cuproptosis, a newly identified copper (Cu)-dependent form of cell death, stands out due to its distinct mechanism that sets it apart from other known cell death pathways. The molecular underpinnings of cuproptosis involve the binding of Cu to lipoylated enzymes in the tricarboxylic acid cycle. This interaction triggers enzyme aggregation and proteotoxic stress, culminating in cell death. The specific mechanism of cuproptosis has yet to be fully elucidated. This newly recognized form of cell death has sparked numerous investigations into its role in tumorigenesis and cancer therapy. In this review, we summarized the current knowledge on Cu metabolism and its link to cancer. Furthermore, we delineated the molecular mechanisms of cuproptosis and summarized the roles of cuproptosis-related genes in cancer. Finally, we offered a comprehensive discussion of the most recent advancements in Cu ionophores and nanoparticle delivery systems that utilize cuproptosis as a cutting-edge strategy for cancer treatment.

Nutrient-delivery and metabolism reactivation therapy for melanoma

To fulfil the demands of rapid proliferation, tumour cells undergo significant metabolic alterations. Suppression of hyperactivated metabolism has been proven to counteract tumour growth. However, whether the reactivation of downregulated metabolic pathways has therapeutic effects remains unexplored. Here we report a nutrient-based metabolic reactivation strategy for effective melanoma treatment. L-Tyrosine-oleylamine nanomicelles (MTyr-OANPs) were constructed for targeted supplementation of tyrosine to reactivate melanogenesis in melanoma cells. We found that reactivation of melanogenesis using MTyr-OANPs significantly impeded the proliferation of melanoma cells, primarily through the inhibition of glycolysis. Furthermore, leveraging melanin as a natural photothermal reagent for photothermal therapy, we demonstrated the complete eradication of tumours in B16F10 melanoma-bearing mice through treatment with MTyr-OANPs and photothermal therapy. Our strategy for metabolism activation-based tumour treatment suggests specific nutrients as potent activators of metabolic pathways.

The association between zinc and prostate cancer development: A systematic review and meta-analysis

BACKGROUND

Prostate cancer is affecting males globally, with several complications. Zinc can play roles in cancers. We aimed to clarify the association between zinc levels or intake with prostate cancer development.

METHODS

We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science until May 1, 2023. We included case-controls and cross-sectionals that measured zinc level and/or intake in patients with prostate cancer or cohorts that evaluated the association between zinc and prostate cancer development. Studies that did not have a healthy control group were excluded. Joanna Briggs Institute was used for quality assessment. Publication bias was evaluated using Egger's and Begg's tests and funnel plot.

RESULTS

Overall, 52 studies (n = 44 case controls, n = 4 cohorts, and n = 4 cross sectionals) with a total number of 163909 participants were included. Serum (standardized mean difference (SMD): -1.11; 95% confidence interval (CI): -1.67, -0.56), hair (SMD: -1.31; 95% CI: -2.19, -0.44), and prostatic fluid or tissue zinc levels (SMD: -3.70; 95% CI: -4.90, -2.49) were significantly lower in prostate cancer patients. There were no significant differences in nail zinc level and zinc intake between those with prostate cancer and healthy controls. There was no publication bias except for serum and hair zinc levels based on Begg's and Egger's tests, respectively. The mean risk of bias scores were 4.61 in case-controls, eight in cohorts, and seven in cross-sectionals.

CONCLUSIONS

Overall, high zinc levels might have a protective role in prostate cancer, which can be used as a therapeutic or preventive intervention. Future large-scale studies are needed to confirm the association.

Toenail zinc and risk of prostate cancer in the MCC-Spain case-control study

BACKGROUND

Some researchers have suggested that zinc (Zn) could reduce the risk of prostate cancer (PC). However, research from observational studies on the relationship between PC risk and biomarkers of Zn exposure shows conflicting results.

OBJECTIVES

To evaluate the association between toenail Zn and PC, considering tumour extension and aggressiveness, along with a gene-environment approach, exploring the interaction of individual genetic susceptibility to PC in the relationship between toenail Zn and PC.

METHODS

In MCC-Spain study we invited all incident PC cases diagnosed in the study period (2008-2013) and recruited randomly selected general population controls. In this report we included 913 cases and 1198 controls with toenail Zn determined by inductively coupled plasma mass spectrometry. To measure individual genetic susceptibility, we constructed a polygenic risk score based on known PC-related single nucleotide polymorphisms. The association between toenail Zn and PC was explored with mixed logistic and multinomial regression models.

RESULTS

Men with higher toenail Zn had higher risk of PC (OR quartile 4 vs.1: 1.41; 95% CI: 1.07-1.85). This association was slightly higher in high-grade PC [(ISUP≤2 Relative risk ratio (RRR) quartile 4 vs.1: 1.36; 1.01-1.83) vs. (ISUP3-5 RRR quartile 4 vs.1: 1.64; 1.06-2.54)] and in advanced tumours [(cT1-cT2a RRR quartile 4 vs.1: 1.40; 95% CI: 1.05-1.89) vs. (cT2b-cT4 RRR quartile 4 vs.1: 1.59; 1.00-2.53)]. Men with lower genetic susceptibility to PC were those at higher risk of PC associated with high toenail Zn (OR quartile 4 vs.1: 2.18; 95% CI: 1.08-4.40).

DISCUSSION

High toenail Zn levels were related to a higher risk for PC, especially for more aggressive or advanced tumours. This effect was stronger among men with a lower genetic susceptibility to PC.

Correlation between Selenium and Zinc Levels and Survival among Prostate Cancer Patients

The most prevalent type of cancer among males is prostate cancer. Survival is considered quite good, but it can be further improved when risk factors are optimized. One of these factors is micronutrients, including Se and Zn. To our knowledge, the interaction between Se and Zn and prostate cancer remains undescribed. This study aimed to investigate the optimal levels of selenium (Se) and zinc (Zn) and their impact on the survival of individuals diagnosed with prostate cancer. A total of 338 prostate cancer patients were enrolled in this study, which was conducted in Poland between 2009 and 2015. Mass spectrometry, which uses inductively coupled plasma mass, was used to assess serum element levels before treatment. The study participants were categorized into quartiles (QI-QIV) based on the distributions of Se and Zn levels observed among surviving participants. Cox regression was used to assess the association between serum Se and Zn levels and the survival of prostate cancer patients. Our results reveal the effect of combined Se and Zn levels on survival in prostate cancer patients (SeQI-ZnQI vs. SeQIV-ZnQIV; HR = 20.9). These results need further research to establish Se/Zn norms for different populations.

Deciphering Molecular Mechanisms Involved in the Modulation of Human Aquaporins' Water Permeability by Zinc Cations: A Molecular Dynamics Approach

Aquaporins (AQPs) constitute a wide family of water channels implicated in all kind of physiological processes. Zinc is the second most abundant trace element in the human body and a few studies have highlighted regulation of AQP0 and AQP4 by zinc. In the present work, we addressed the putative regulation of AQPs by zinc cations in silico through molecular dynamics simulations of human AQP0, AQP2, AQP4, and AQP5. Our results align with other scales of study and several in vitro techniques, hence strengthening the reliability of this regulation by zinc. We also described two distinct putative molecular mechanisms associated with the increase or decrease in AQPs' water permeability after zinc binding. In association with other studies, our work will help deciphering the interaction networks existing between zinc and channel proteins.

Biomimetic Nano-Immunoactivator via Ionic Metabolic Modulation for Strengthened NIR-II Photothermal Immunotherapy

Reprogramming the immunologically "cold" environment of solid tumors is currently becoming the mainstream strategy to elicit powerful and systemic anticancer immunity. Here, a facile and biomimetic nano-immunnoactivator (CuS/Z@M4T1 ) is detailed by engineering a Zn2+ -bonded zeolitic imidazolate framework-8 (ZIF-8) with CuS nanodots (NDs) and cancer cell membrane for amplified near-infrared-II (NIR-II) photothermal immunotherapy via Zn2+ metabolic modulation. Taking advantage of the NIR-II photothermal effect of CuS NDs and the acidic responsiveness of ZIF-8, CuS/Z@M4T1 rapidly causes intracellular Zn2+ pool overload and disturbs the metabolic flux of 4T1 cells, which effectively hamper the production of heat shock proteins and relieve the resistance of photothermal therapy (PTT). Thus, amplified immunogenic cell death is evoked and initiates the immune cascade both in vivo and in vitro as demonstrated by dendritic cells maturation and T-cell infiltration. Further combination with antiprogrammed death 1 (aPD-1) achieves escalated antitumor efficacy which eliminates the primary, distant tumor and avidly inhibits lung metastasis due to cooperation of enhanced photothermal stimulation and empowerment of cytotoxic T lymphocytes by aPD-1. Collectively, this work provides the first report of using the intrinsic modulation property of meta-organometallic ZIF-8 for enhanced cancer photoimmunotherapy together with aPD-1, thereby inspiring a novel combined paradigm of ion-rich nanomaterials for cancer treatment.

Serum Cu, Zn and IL-1β Levels May Predict Fetal Miscarriage Risk After IVF Cycles: A Nested Case-Control Study

To explore the association between serum-related indicators (levels of inflammatory cytokines and essential trace elements) and miscarriage risk among infertile women undergoing assisted reproductive techniques (ART) on the 14th day after embryo transfer, and to develop and establish a multivariable algorithm model that might predict pregnancy outcome. According to a nested case-control study design, a total of 100 miscarriage cases and 100 live birth controls were included in this study, and women in both groups were infertile and have underwent in vitro fertilization (IVF). Pregnancy tests were performed and serum levels of five essential trace elements (vanadium (V), copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo)) and five inflammatory cytokines (interleukin-1β (IL-1β), IL-6, IL-8, IL-10 and tumor necrosis factor-α (TNF-α)) of the participants were measured on the 14th day after embryo transfer. The serum levels of five inflammatory cytokines were determined by multiple magnetic bead enzyme immunity analyzer; and the serum concentrations of five elements were determined simultaneously by inductively coupled plasma‒mass spectrometry (ICP ‒ MS). The logistic regression was used to evaluate the relationship between these serum indices and miscarriage risk among women undergoing ART, and a predictive model of pregnancy outcome based on these indices was established. The levels of IL-10, IL-1β and TNF-α of infertile women in the live birth group were significantly higher than those in the miscarriage group (p = 0.009, p < 0.001, p = 0.006), and the levels of V, Cu, Zn and Se of infertile women in the live birth group were also significantly higher than those in the miscarriage group (all p < 0.001). Through logistic regression analyses, we found that serum levels of IL-1β, TNF-α, V, Cu, Zn and Se were significantly and negatively associated with miscarriage risk. Different combination prediction models were generated according to the results of logistic regression analyses, and the combination of IL-1β, Cu and Zn had the best prediction performance. The area under the curve (AUC) was 0.776, the sensitivity of the model was 60% and the specificity was 84%. In conclusion, the serum-related indicators of women undergoing ART on the 14th day after embryo transfer, including the inflammatory cytokines such as IL-1β and TNF-α and the essential trace metal elements such as V, Cu, Zn and Se, were negatively correlated with miscarriage risk. A multivariate algorithm model to predict pregnancy outcome among women undergoing ART was established, which showed that IL-1β, Cu and Zn might synergistically predict pregnancy outcome.

Exploring the potential function of trace elements in human health: a therapeutic perspective

A trace element, known as a minor element, is a chemical element whose concentration is very low. They are divided into essential and non-essential classes. Numerous physiological and metabolic processes in both plants and animals require essential trace elements. These essential trace elements are so directly related to the metabolic and physiologic processes of the organism that either their excess or deficiency can result in severe bodily malfunction or, in the worst situations, death. Elements can be found in nature in various forms and are essential for the body to carry out its varied functions. Trace elements are crucial for biological, chemical, and molecular cell activity. Nutritional deficits can lead to weakened immunity, increased susceptibility to oral and systemic infections, delayed physical and mental development, and lower productivity. Trace element enzymes are involved in many biological and chemical processes. These compounds act as co-factors for a number of enzymes and serve as centers for stabilizing the structures of proteins and enzymes, allowing them to mediate crucial biological processes. Some trace elements control vital biological processes by attaching to molecules on the cell membrane's receptor site or altering the structure of the membrane to prevent specific molecules from entering the cell. Some trace elements are engaged in redox reactions. Trace elements have two purposes. They are required for the regular stability of cellular structures, but when lacking, they might activate alternate routes and induce disorders. Therefore, thoroughly understanding these trace elements is essential for maintaining optimal health and preventing disease.

Role of monocarboxylate transporters and glucose transporters in prostate cancer

OBJECTIVES

Currently, research of new diagnostic approaches to detect clinically significant prostate cancer is relevant because of the importance of early detection of aggressive forms of the disease, often challenging, even when using modern diagnostic tools. The aim of this review is to present the current knowledge regarding monocarboxylate transporters' and glucose transporters' expression as a component of glycolytic phenotype definition in prostate cancer cells.

METHODS

We searched PubMed and Scopus databases. Twenty-six articles from 2003 to 2022 were included. Literature research and selection were carried out based on the recommendations of the PRISMA statement.

RESULTS

The presence of "lactate shuttle" in the tumor tissue is associated with a worse prognosis. Increased expression of MCT2, MCT4, GLUT1, and down-regulation of GLUT3 are associated with prostate adenocarcinoma. MCT4 expression level correlates with the grade of tumor malignancy and disease prognosis. Up-regulation of GLUT1 and MCT4 is typical for hormone-resistant prostate cancer. Inhibition of MCT1 and MCT4 and GLUT1 in prostate cancer cells reduces their metabolic activity and growth rate, a suitable novel approach for targeted therapy.

CONCLUSION

Review of the current studies showed that expression of certain MCTs and GLUTs types are associated with prostate cancer and some of them correlate with high malignancy and poor prognosis. Detection by immunohistochemistry of these transporters could represent a new diagnostic tool to identify aggressive forms of prostate cancer, and a novel therapeutic target for selective drugs.

Cadmium exposure and the risk of prostate cancer among Nigerian men: effect modification by zinc status

BACKGROUND

Prostate cancer (PCa) may result from an interplay between many factors including exposure to trace elements. This study examined the association between cadmium exposure and PCa among Nigerian men and evaluated possible modification of this effect by zinc status.

METHODS

This case-control study involved men with histologically confirmed PCa (n = 82), benign prostatic hyperplasia (BPH; n = 93) and controls (n = 98), aged between 40 and 80 years. Study participants were recruited from the main teaching hospital that draws clients from the entire Anambra State in South-Eastern Nigeria. Blood and urine samples were collected from these participants and were analyzed for trace elements using ICP-MS. Statistical models were used to assess the exposure risk for cadmium exposure as well as the mediating effect of zinc status.

RESULTS

Among men with prostatic disorders (case-case analysis), every 10-fold increase in urinary cadmium was associated with increased risk of PCa (adjusted odds ratios: 2.526; 95% CI: 1.096-5.821). Men in the highest blood zinc quartile had lower odds of PCa compared to the lowest quartile (AOR: 0.19; 95% CI, 0.06-0.54; p-for trend = 0.001). Zinc-specific effect was observed in this group: every 10-fold increase in urinary cadmium was associated with increased risk of PCa among men with creatinine-adjusted urinary zinc levels below the median value (AOR: 8.46; 95% CI: 1.97 -36.39) but not in those above the median value (AOR: 1.55; 95% CI: 0.45 - 5.39).

CONCLUSION

Higher exposure to cadmium may be associated with increased risk of PCa in Nigeria and probably other countries with high prevalence of Zn deficiency. These results point to the need to consider co-occurring trace metals in any effort to mitigate the toxicity of Cd in the environment.

Carrier-free nanoprodrug for p53-mutated tumor therapy via concurrent delivery of zinc-manganese dual ions and ROS

Human cancers typically express a high level of tumor-promoting mutant p53 protein (Mutp53) with a minimal level of tumor-suppressing wild-type p53 protein (WTp53). In this regard, inducing Mutp53 degradation while activating WTp53 is a viable strategy for precise anti-tumor therapy. Herein, a new carrier-free nanoprodrug (i.e., Mn-ZnO₂ nanoparticles) was developed for concurrent delivery of dual Zn-Mn ions and reactive oxygen species (ROS) within tumor to regulate the p53 protein for high anti-tumor efficacy. In response to the mild tumor acidic environment, the released Zn²⁺ and H₂O₂ from Mn-ZnO₂ NPs induced ubiquitination-mediated proteasomal degradation of Mutp53, while the liberative Mn²⁺ and increased ROS level activated the ATM-p53-Bax pathway to elevate WTp53 level. Both in vitro and in vivo results demonstrated that pH-responsive decomposition of Mn-ZnO₂ NPs could effectively elevate the intracellular dual Zn-Mn ions and ROS level and subsequently generate the cytotoxic hydroxyl radical (•OH) through the Fenton-like reaction. With the integration of multiple functions (i.e., carrier-free ion and ROS delivery, tumor accumulation, p53 protein modulation, toxic •OH generation, and pH-activated MRI contrast) in a single nanosystem, Mn-ZnO₂ NPs demonstrate its superiority as a promising nanotherapeutics for p53-mutated tumor therapy.

MRI Methods for Imaging Beta-Cell Function in the Rodent Pancreas

The role of Zn2+ ions in proper storage of insulin in β-cell granules is well-established so when insulin is secreted from β-cells stimulated by an increase in plasma glucose, free Zn2+ ions are also released. This local increase in Zn2+ can be detected in the pancreas of rodents in real time by the use of a zinc-responsive MR contrast agent. This method offers the opportunity to monitor β-cell function longitudinally in live rodents. The methods used in our lab are fully described in this short report and some MR images of a rat pancreas showing clearly enhanced hot spots in the tail are presented.

Zinc in Prostate Health and Disease: A Mini Review

Introduction-With the high global prevalence of prostate cancer and associated mortalities, it is important to enhance current clinical practices for better prostate cancer outcomes. The current review is towards understanding the value of Zn towards this mission. Method-General information on Zn in biology and multiple aspects of Zn involvement in prostate health and disease were referred to in PubMed. Results-The most influential feature of Zn towards prostate health is its ability to retain sufficient citrate levels for a healthy prostate. Zn deficiencies were recorded in serum, hair, and prostate tissue of men with prostate cancer compared to non-cancer controls. Zn gut absorption, albumin binding, and storage compete with various factors. There are multiple associations of Zn cellular influx and efflux transporters, Zn finger proteins, matrix metalloproteinases, and Zn signaling with prostate cancer outcomes. Such Zn marker variations associated with prostate cancer recorded from biological matrices may improve algorithms for prostate cancer screening, prognosis, and management when coupled with standard clinical practices. Discussion-The influence of Zn in prostatic health and disease is multidimensional, therefore more personalized Zn requirements may be beneficial. Several opportunities exist to utilize and improve understanding of Zn associations with prostate health and disease.

Smart biomaterials for enhancing cancer therapy by overcoming tumor hypoxia: a review

Hypoxia is a distinctive feature of most solid tumors due to insufficient oxygen supply of the abnormal vasculature, which cannot work with the demands of the fast proliferation of cancer cells. One of the main obstacles to limiting the efficacy of cancer medicines is tumor hypoxia. Thus, oxygen is a vital parameter for controlling the efficacy of different types of cancer therapy, such as chemotherapy (CT), photodynamic therapy (PDT), photothermal therapy (PTT), immunotherapy (IT), and radiotherapy (RT). Numerous technologies have attracted much attention for enhancing oxygen distribution in humans and improving the efficacy of cancer treatment. Such technologies include treatment with hyperbaric oxygen therapy (HBO), delivering oxygen by polysaccharides (e.g., cellulose, gelatin, alginate, and silk) and other biocompatible synthetic polymers (e.g., PMMA, PLA, PVA, PVP and PCL), decreasing oxygen consumption, producing oxygen in situ in tumors, and using polymeric systems as oxygen carriers. Herein, this review provides an overview of the relationship between hypoxia in tumor cells and its role in the limitation of different cancer therapies alongside the numerous strategies for oxygen delivery using polysaccharides and other biomaterials as carriers and for oxygen generation.

Association between pre-diagnostic dietary copper, zinc, and copper-to-zinc ratio and severity of ovarian cancer

BACKGROUND

The impact of dietary trace elements intake on ovarian cancer (OC) severity is unknown.

OBJECTIVE

We firstly explore the relationship between dietary copper (Cu), zinc (Zn), and copper-to-zinc (Cu/Zn) ratio and severity of OC.

METHODS

This cross-sectional study included 701 women from the OC follow-up study between 2015 and 2020. Dietary information was collected by a validated food frequency questionnaire (FFQ). The severity information of OC including age at diagnosis, histological type, International Federation of Gynecology and Obstetrics (FIGO) stage, and histopathologic grade was ascertained from medical records. Logistic regression model was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of aforementioned associations.

RESULTS

Among 701 participants, the number of patients age at diagnosis older than 50 were 443 (63.2%). The number of patients diagnosed as serous, III-IV stage, and poorly differentiation OC were 477 (68.05%), 336 (47.93%), and 597 (85.16%), respectively. In addition, compared with the lowest tertile intake, higher possibility of non-serous OC was associated with the pre-diagnosis dietary Cu (OR = 2.39, 95% CI = 1.28-4.47, p trend < 0.05) and Cu/Zn ratio (OR = 2.06, 95% CI = 1.26-3.39, P trend < 0.05) in the highest tertile intake. The risk of poorly differentiation OC at diagnosis was significant inversely related to dietary Cu intake (OR = 0.40, 95% CI = 0.18-0.88, P trend < 0.05). Besides, the results of subgroup analyses were consistent with the main findings but not all of them showed statistical significance.

CONCLUSION

Pre-diagnostic dietary Cu and Cu/Zn ratio were contributed to reducing the severity of OC at diagnosis, especially for the risk of serous OC and poorly differentiation OC.

Chemical Factory-Guaranteed Enhanced Chemodynamic Therapy for Orthotopic Liver Cancer

In the field of nanomedicine, there is a tendency of matching designed nanomaterials with a suitable type of orthotopic cancer model, not just a casual subcutaneous one. Under this condition, knowing the specific features of the chosen cancer model is the priority, then introducing a proper therapy strategy using designed nanomaterials. Here, the Fenton chemistry is combined with zinc peroxide nanoparticles in the treatment of orthotopic liver cancer which has a "chemical factory" including that liver is the main place for iron storage, metabolism, and also the main metabolic sites for the majority of ingested substances, guaranteeing customized and enhanced chemodynamic therapy and normal liver cells protection as well. The good results in vitro and in vivo can set an inspiring example for exploring and utilizing suitable nanomaterials in corresponding cancer models, ensuring well-fitness of nanomaterials for disease and satisfactory therapeutic effect.

Mitochondria Dysfunction-Mediated Molecular Subtypes and Gene Prognostic Index for Prostate Cancer Patients Undergoing Radical Prostatectomy or Radiotherapy

Background

Given the age relevance of prostate cancer (PCa) and the role of mitochondrial dysfunction (MIDS) in aging, we orchestrated molecular subtypes and identified key genes for PCa from the perspective of MIDS.

Methods

Cluster analysis, COX regression analysis, function analysis, and tumor immune environment were conducted. We performed all analyses using software R 3.6.3 and its suitable packages.

Results

CXCL14, SFRP4, and CD38 were eventually identified to classify the PCa patients in The Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) dataset into two distinct clusters. Patients in the cluster 2 had shorter BCR-free survival than those in the cluster 1 in terms of both TCGA database and GEO dataset. We divided the patients from the TCGA database and the GEO dataset into high- and low-risk groups according to the median of MIDS-related genetic prognostic index. For patients in the TCGA database, the biochemical recurrence (BCR) risk in high-risk group was 2.34 times higher than that in low-risk group. Similarly, for patients in the GEO dataset, the risk of BCR and metastasis in high-risk group was 2.35 and 3.04 times higher than that in low-risk group, respectively. Cluster 2 was closely associated with advanced T stage and higher Gleason score for patients undergoing radical prostatectomy or radiotherapy. For patients undergoing radical prostatectomy, the number of CD8⁺ T cells was significantly lower in cluster 2 than in cluster 1, while cluster 2 had significantly higher stromal score than cluster 1. For patients undergoing radical radiotherapy, cluster 2 had significantly higher level of CD8⁺ T cells, neutrophils, macrophages, dendritic cells, stromal score, immune score, and estimate score, but showed lower level of tumor purity than cluster 1.

Conclusions

We proposed distinctly prognosis-related molecular subtypes at genetic level and related formula for PCa patients undergoing radical prostatectomy or radiotherapy, mainly to provide a roadmap for precision medicine.

Quantitative Analysis of Serum Zinc Levels in Primary Brain Tumor Patients

Although the close relationships between most of the trace elements and tumor formation mechanisms are very well-defined, studies on some elements such as zinc are still ongoing. When examining studies on brain tumors, it was observed that studies investigating the role played by serum zinc levels on tumor etiology and prognosis have gained momentum. In this study, we investigate the relationship between different brain tumor types and serum zinc levels by quantitatively analyzing serum zinc levels in patients with primary brain tumors. In this study, we measured serum zinc levels of 33 brain tumor patients as well as 35 healthy individuals serving as a control group. Metal concentrations were measured using atomic absorption spectrophotometry. Serum zinc levels were lower in patients with primary brain tumors compared to control group (p < 0.05). Additionally, patients' serum zinc levels were significantly different according to their brain tumor types and also according to their age (p < 0.05). Our findings suggest that brain tumor patients' serum zinc levels may play a role in tumor etiology, typology, and prognosis.

Zinc supplement use and risk of aggressive prostate cancer: a 30-year follow-up study

BACKGROUND

Zinc supplementation was hypothesized to have therapeutic potential against prostate cancer, but its influence on prostate cancer incidence especially at high doses is controversial.

METHODS

A total of 47,240 men from the Health Professionals Follow-up Study were followed from 1986 to 2016. Men reported their zinc supplement use at baseline and biennially thereafter. Clinical features of prostate cancer included stage, grade, lethal and aggressive (T4 or N1 or M1 or Gleason 8-10) outcome. Multivariable Cox proportional hazards models were used to evaluate the association between zinc supplement use and incidence of prostate cancer.

RESULTS

During a median follow-up of 28.3 years, we documented 6,980 incident prostate cancer cases including 1,053 lethal and 1,143 aggressive. Zinc supplement use was not associated with overall, localized, low- and intermediate-grade prostate cancer. However, compared to never-users, men who used supplement zinc more than 75 mg/day were at higher risk for lethal (HR: 1.76, 95% CI: 1.16-2.66, P_trend = 0.001) and aggressive prostate cancer (HR: 1.80, 95% CI: 1.19-2.73, P_trend = 0.006). Similarly, men who took supplemental zinc for 15 or more years had a higher risk for lethal (HR: 1.91, 95% CI: 1.28-2.85, P_trend <0.001) and aggressive prostate cancer (HR: 1.55, 95% CI: 1.03-2.33, P_trend = 0.004).

CONCLUSION

Zinc supplementation of more than 75 mg per day or over 15 years may substantially increase risk of lethal and aggressive prostate cancer. Caution is warranted regarding excessive usage of zinc supplements among adult men.

Noninvasive urine metabolomics of prostate cancer and its therapeutic approaches: a current scenario and future perspective

INTRODUCTION

The sensitive, specific, fast, robust and noninvasive biomarkers for the evaluation of prostate cancer (PC) remain elusive in medical research. However, efforts are in full sway to investigate and resolve these puzzles for clinical practice. Advances in modern analytical techniques, sample processing, and the emergence of multiple omics approaches have created a great hope for the development of better detection modalities for PC. The objective of the present review is to provide a concise overview of the PC metabolomics-based potential discriminating molecules in urine samples using nuclear magnetic resonance spectroscopy and mass spectrometry.

AREA COVERED

A literature search was executed to find the studies reporting the noninvasive urine-based biomarkers for the diagnosis and prognosis of underlying disease. Most studies have extensivelyreported PC discriminating molecules with their respective controls. Additionally, pathophysiology and the treatment paradigm of PC are summarized and related to the insights underpinning the therapeutic intervention of PC.

EXPERT OPINION

With multi-centric, global, comprehensive omics approaches via either a non- or least-invasive bio-matrix may open new avenues of research for PC biomarker discovery, backed by a molecular mechanistic outline.

The ion channel TRPM7 regulates zinc-depletion-induced MDMX degradation

Zinc deficiency has been linked to human diseases, including cancer. MDMX, a crucial zinc-containing negative regulator of p53, has been found to be amplified or overexpressed in various cancers and implicated in the cancer initiation and progression. We report here that zinc depletion by the ion chelator TPEN or Chelex resin results in MDMX protein degradation in a ubiquitination-independent and 20S proteasome-dependent manner. Restoration of zinc led to recovery of cellular levels of MDMX. Further, TPEN treatment inhibits growth of the MCF-7 breast cancer cell line, which is partially rescued by overexpression of MDMX. Moreover, in a mass-spectrometry-based proteomics analysis, we identified TRPM7, a zinc-permeable ion channel, as a novel MDMX-interacting protein. TRPM7 stabilizes and induces the appearance of faster migrating species of MDMX on SDS-PAGE. Depletion of TRPM7 attenuates, while TRPM7 overexpression facilitates, the recovery of MDMX levels upon adding back zinc to TPEN-treated cells. Importantly, we found that TRPM7 inhibition, like TPEN treatment, decreases breast cancer cell MCF-7 proliferation and migration. The inhibitory effect on cell migration upon TRPM7 inhibition is also partially rescued by overexpression of MDMX. Together, our data indicate that TRPM7 regulates cellular levels of MDMX in part by modulating the intracellular Zn²⁺ concentration to promote tumorigenesis.

Metal peroxides for cancer treatment

In recent years, metal peroxide (MO2) such as CaO2 has received more and more attention in cancer treatment. MO2 is readily decompose to release metal ions and hydrogen peroxide in the acidic tumor microenvironment (TME), resulting metal ions overloading, decreased acidity and elevated oxidative stress in TME. All of these changes making MO2 an excellent tumor therapeutic agent. Moreover, by combining MO2 with photosensitizers, enzymes or Fenton reagents, MO2 can assist and promote various tumor therapies such as photodynamic therapy and chemodynamic therapy. In this review, the synthesis and modification methods of MO2 are introduced, and the representative studies of MO2-based tumor monotherapy and combination therapy are discussed in detail. Finally, the current challenges and prospects of MO2 in the field of tumor therapy are emphasized to promote the development of MO2-based cancer treatment.

The Involvement of the Oxidative Stress Status in Cancer Pathology: A Double View on the Role of the Antioxidants

Oxygen-free radicals, reactive oxygen species (ROS) or reactive nitrogen species (RNS), are known by their "double-sided" nature in biological systems. The beneficial effects of ROS involve physiological roles as weapons in the arsenal of the immune system (destroying bacteria within phagocytic cells) and role in programmed cell death (apoptosis). On the other hand, the redox imbalance in favor of the prooxidants results in an overproduction of the ROS/RNS leading to oxidative stress. This imbalance can, therefore, be related to oncogenic stimulation. High levels of ROS disrupt cellular processes by nonspecifically attacking proteins, lipids, and DNA. It appears that DNA damage is the key player in cancer initiation and the formation of 8-OH-G, a potential biomarker for carcinogenesis. The harmful effect of ROS is neutralized by an antioxidant protection treatment as they convert ROS into less reactive species. However, contradictory epidemiological results show that supplementation above physiological doses recommended for antioxidants and taken over a long period can lead to harmful effects and even increase the risk of cancer. Thus, we are describing here some of the latest updates on the involvement of oxidative stress in cancer pathology and a double view on the role of the antioxidants in this context and how this could be relevant in the management and pathology of cancer.

Nutritional supplementation of the pharmacotherapy of prostate diseases

Introduction: Nutritional supplementation is an integral part of modern pharmacotherapeutic strategies for prostate diseases with different levels of evidence for specific nutrients.

Provitamin A (beta-carotene), vitamin A (retinol) and prostate diseases. Their effects have not been sufficiently studied, and the available data are conflicting to recommend them as a nutritional supplement.

Vitamin E (tocopherol) and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicting to recommend it as a nutritional supplement.

Vitamin C (ascorbic acid) and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicted to recommend it as a nutritional supplement.

Vitamin K and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicted to recommend it as a nutritional supplement.

Vitamin D and prostate diseases. The evidence base of the vitamin D prostatotropic effects has been accumulated, which allows us to consider its deficiency replacement as an effective nutritional supplement in prostate diseases.

Omega-3 PUFAs and prostate diseases. They have universal physiological effects; however, the evidence base for their recommendation as a nutritional supplement for prostate diseases is still insufficient.

Zinc and prostate diseases. Positive effects of zinc on the prostate gland are known for a fact and allow us to recommend it as a nutritional supplement for prostate diseases.

Selenium and prostate diseases. The reliably proven positive effects of selenium on the prostate gland allow us to recommend it as a nutritional supplement for prostate diseases.

Magnesium and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicting to recommend it as a nutritional supplement.

Survival of Laryngeal Cancer Patients Depending on Zinc Serum Level and Oxidative Stress Genotypes

Stress contributes to various aspects of malignancy and could influence survival in laryngeal cancer patients. Among antioxidant mechanisms, zinc and the antioxidant enzymes superoxide dismutase 2, catalase and glutathione peroxidase 1 play a major role. The aim of this study was a prospective evaluation of the survival of patients with laryngeal cancer in relation to serum levels of zinc in combination with functional genotype differences of three key antioxidant enzymes. The study group consisted of 300 patients treated surgically for laryngeal cancer. Serum zinc levels and common polymorphisms in SOD2, CAT and GPX1 were analyzed. The risk of death in patients with the lowest zinc levels was increased in comparison with patients with the highest levels. Polymorphisms of antioxidant genes by themselves were not correlated with survival, however, serum zinc level impact on survival was stronger for SOD2 TC/TT and CAT CC variants. GPX1 polymorphisms did not correlate with zinc levels regarding survival. In conclusion, serum zinc concentration appears to be an important prognostic factor for survival of patients diagnosed with laryngeal cancer. When higher zinc levels were correlated with polymorphisms in SOD2 and CAT a further increase in survival was observed.

Transcriptomic insights into the zinc homeostasis of MCF-7 breast cancer cells via next-generation RNA sequencing

A significant gap in the knowledge of zinc homeostasis exists for breast cancer cells. In this study, we investigated the transcriptomic response of the luminal breast cancer cells (MCF-7) to the exposure of extracellular zinc using next-generation RNA sequencing. The dataset was collected for three time points (T0, T30, and T120) in the time course of zinc treatment, which revealed the dramatic increase, up to 869-fold, of the gene expression for metallothioneins (MT1B, MT1F, MT1X, and MT2A) and the zinc exporter ZnT1 (SLC30A1) at T30, continuingly through to T120. The similar dynamic expression pattern was found for the autophagy-related gene (VMP1) and numerous genes for zinc finger proteins (e.g. RNF165, ZNF365, ZBTB2, SNAI1, ZNF442, ZNF547, ZNF563, and ZNF296). These findings point to the all-hands-on-deck strategy adopted by the cancer cells for maintaining zinc homeostasis. The stress responsive genes encoding heat shock proteins (HSPA1A, HSPA1B, HSPA1L, HSPA4L, HSPA6, HSPA8, HSPH1, HSP90AA1, and HSP90AB1) and the MTF-1 biomarker genes (AKR1C2, CLU, ATF3, GDF15, HMOX1, MAP1A, MAFG, SESN2, and UBC) were also differentially up-regulated at T120, suggesting a role of heat shock proteins and the MTF-1 related stress proteins in dealing with zinc exposure. It is for the first time that the gene encoding Polo-like kinase 2 (PLK2) was found to be involved in zinc-related response. The top differentially expressed genes were validated by qRT-PCR and further extended to the basal type breast cancer cells (MDA-MB-231). It was found that the expression level of SLC30A1 in MDA-MB-231 was higher than MCF-7 in response to zinc exposure. Taken together, the findings contribute to our knowledge and understanding of zinc homeostasis in breast cancer cells.

ZnT7 RNAi favors RafGOFscrib-/--induced tumor growth and invasion in Drosophila through JNK signaling pathway

The disruption of zinc homeostasis has been identified in patients suffering from various cancers, but a causative relationship has not yet been established. Drosophila melanogaster has become a powerful model to study cancer biology. Here using a Drosophila model of malignant tumor Raf^GOFscrib^-/-, we observed that the tumor growth, invasion and migration were enhanced by silencing dZnT7, a zinc transporter localized on the Golgi apparatus. Further study indicated that the zinc deficiency in Golgi of dZnT7 RNAi resulted in ER stress which could activate the c-Jun-N-terminal Kinase (JNK) signaling and this process is mediated by Atg9. Lastly, we demonstrated that the exacerbation of dZnT7 RNAi on tumor was promoted by JNK signaling-dependent cell autonomous and non-autonomous autophagy. These findings suggest that zinc homeostasis in secretory compartments may provide a new therapeutic target for tumor treatment.

Systematic Comparison of Vesicular Targeting Signals Leads to the Development of Genetically Encoded Vesicular Fluorescent Zn2+ and pH Sensors

Genetically encoded fluorescent sensors have been widely used to illuminate secretory vesicle dynamics and the vesicular lumen, including Zn²⁺ and pH, in living cells. However, vesicular sensors have a tendency to mislocalize and are susceptible to the acidic intraluminal pH. In this study, we performed a systematic comparison of five different vesicular proteins to target the fluorescent protein mCherry and a Zn²⁺ Förster resonance energy transfer (FRET) sensor to secretory vesicles. We found that motifs derived from vesicular cargo proteins, including chromogranin A (CgA), target vesicular puncta with greater efficacy than transmembrane proteins. To characterize vesicular Zn²⁺ levels, we developed CgA-Zn²⁺ FRET sensor fusions with existing sensors ZapCY1 and eCALWY-4 and characterized subcellular localization and the influence of pH on sensor performance. We simultaneously monitored Zn²⁺ and pH in individual secretory vesicles by leveraging the acceptor fluorescent protein as a pH sensor and found that pH influenced FRET measurements in situ. While unable to characterize vesicular Zn²⁺ at the single-vesicle level, we were able to monitor Zn²⁺ dynamics in populations of vesicles and detected high vesicular Zn²⁺ in MIN6 cells compared to lower levels in the prostate cancer cell line LnCaP. The combination of CgA-ZapCY1 and CgA-eCALWY-4 allows for measurement of Zn²⁺ from pM to nM ranges.

Carbon Nanohorns/Pt Nanoparticles/DNA Nanoplatform for Intracellular Zn2+ Imaging and Enhanced Cooperative Phototherapy of Cancer Cells

Superfluous zinc ion (Zn²⁺) in living cells has been identified as a potential tumor biomarker for early cancer diagnosis and cancer progression monitoring. In this paper, we developed a novel carbon nanohorns/Pt nanoparticles/DNA (CNHs/Pt NPs/DNA) nanoplatform based on the clamped hybridization chain reaction (c-HCR) process for intracellular Zn²⁺ imaging and enhanced cooperative phototherapy of cancer cells. Cross-shaped DNAzyme (c-DNAzyme), hairpin DNA1, hairpin DNA2, and aptamer DNA were adsorbed onto the surfaces of CNHs/Pt NPs, and the fluorescence of carboxytetramethyl-rhodamine was also quenched. After entering the living cells, the c-DNAzyme was cleaved to output trigger DNA in the existence of intracellular Zn²⁺ and initiate the c-HCR process for fluorescence amplification. Compared with the single HCR process triggered by a single DNAzyme, the c-HCR process could further improve the amplification efficiency and sensitivity. In addition, such a nanoprobe possesses a catalysis-enhanced photodynamic effect by Pt NP generation of oxygen in a tumor microenvironment and increases the photothermal effect by loading of Pt NPs on CNHs, indicating that this is a promising biological method for cancer diagnosis and cancer cell therapy.

Antimicrobial and antitumor activity of S-methyl dithiocarbazate Schiff base zinc(II) complexes

Schiff bases (SB) obtained from S-methyl dithiocarbazate and aromatic aldehydes: salicylaldehyde (H₂L¹), o-vanillin (H₂L²), pyridoxal (H₂L³) and 2,6-diformyl-4-methylphenol (H₃L⁴), and their corresponding Zn(II)-complexes (1-4), are synthesized. All compounds are characterized by elemental analyses, infrared, UV-Vis, nuclear magnetic resonance spectroscopy and mass spectrometry. The structures of H₂L² and [Zn₂(L¹)₂(H₂O)(DMF)] (1a) (DMF = dimethylformamide) are solved by single crystal X-ray diffraction. The SB coordinates the metal center through the O_phenolate, N_imine and S_thiolate atoms. The radical scavenging activity is tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with all ligand precursors showing IC₅₀ values ~40 μM. Cytotoxicity studies with several tumor cell lines (PC-3, MCF-7 and Caco-2) as well as a non-tumoral cell line (NHDF) are reported. Interestingly, 1 has relevant and selective antiproliferative effect against Caco-2 cells (IC₅₀ = 9.1 μM). Their antimicrobial activity is evaluated in five bacterial strains (Klebsiella pneumoniae, Acinetobacter baumannii, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus) and two yeast strains (Candida albicans and Candida tropicalis) with some compounds showing bacteriostatic and fungicidal activity. The minimal inhibitory concentration (MIC₉₀) of H_nL against Mycobacterium tuberculosis is also reported, with H₂L² and H₃L⁴ showing very high activity (MIC₉₀ < 0.6 μg/mL). The ability of the compounds to bind bovine serum albumin (BSA) and DNA is evaluated for H₃L⁴ and [Zn₂(L⁴)(CH₃COO)] (4), both showing high binding constants to BSA (ca. 10⁶ M^-1) and ability to bind DNA. Overall, the reported compounds show relevant antitumor and antimicrobial properties, our data indicating they may be promising compounds in several fields of medicinal chemistry.

Imaging Tissue Physiology In Vivo by Use of Metal Ion-Responsive MRI Contrast Agents

Paramagnetic metal ion complexes, mostly based on gadolinium (Gd3+), have been used for over 30 years as magnetic resonance imaging (MRI) contrast agents. Gd3+-based contrast agents have a strong influence on T1 relaxation times and are consequently the most commonly used agents in both the clinical and research environments. Zinc is an essential element involved with over 3000 different cellular proteins, and disturbances in tissue levels of zinc have been linked to a wide range of pathologies, including Alzheimer's disease, prostate cancer, and diabetes mellitus. MR contrast agents that respond to the presence of Zn2+ in vivo offer the possibility of imaging changes in Zn2+ levels in real-time with the superior spatial resolution offered by MRI. Such responsive agents, often referred to as smart agents, are typically composed of a paramagnetic metal ion with a ligand encapsulating it and one or more chelating units that selectively bind with the analyte of interest. Translation of these agents into clinical radiology is the next goal. In this review, we discuss Gd3+-based MR contrast agents that respond to a change in local Zn2+ concentration.

Inflammation factors and element supplementation in cancer

The aim of the study was to evaluate the effect of dietary supplementation with chosen minerals (Zn, Se, Fe) on expression of selected cytokines (IL-1, IL-6, TNFα) in spleen of rats and on their concentrations in rat serum under inflammatory and pathological conditions obtained by implantation of prostate cancer cells (LnCaP). Serum levels of metabolites of arachidonic, eicosapentaenoic and linoleic acids (hydroxyeicosatetraenoic, hydroxyeicosapentaenoic and hydroxyoctadecadienoic acids, respectively), as compounds involved in inflammation and cancer development, were also investigated. Male rats were randomised into dietary groups supplemented with Zn, Se or Fe. Prostate cancer cells were implanted to some rats in each group. The study demonstrated that minerals supplemented with the diet may exert various effects on an organism. Selenium, zinc and iron influence pro-inflammatory cytokine expression, what leads to stimulation of inflammation. They also affect synthesis of arachidonic and linoleic acid metabolites that exert pro-inflammatory action and enable cancer development and metastasis.

Zinc: The Wonder Drug for the Treatment of Carcinomas

Evidence is evolving that support the relationship that all carcinomas exhibit the following important relationships: The malignant cells exhibit a significant decreased zinc compared to the normal cells. The higher zinc levels that exist in the normal cells are cytotoxic in the malignant cells. The decrease in zinc is due to the down regulation of the ZIP-family zinc uptake transporter. These cells are as "ZIP-deficient/decreased zinc" malignancies. This provides a target for a chemotherapy that can restore the high zinc levels that will manifest cytotoxic effects in the malignant cells. In order to achieve this, a vehicle that facilitates the uptake and accumulation of zinc in the ZIP-deficient cells is required. The zinc ionophore, clioquinol, exhibits the properties that will provide these requirements. This is demonstrated by the treatment of a patient with 3% Clioquinol Cream, which successfully suppressed the progression of androgen-dependent prostate cancer. This treatment should also be efficacious for pancreatic cancer, liver cancer, breast cancer, thyroid cancer, kidney cancer, stomach cancer, gall bladder cancer, and lung cancer; which are carcinomas that exhibit decreased zinc. Thus, it is appropriate to describe that "Zinc is the wonder drug for the treatment of carcinomas".

Disparities in Trace Metal Levels in Hodgkin/Non-Hodgkin Lymphoma Patients in Comparison with Controls

Lymphoma arises from cells of the immune system and trace metals augment the immune system and their imbalance may promote immunological disorders including tumorigenesis. The primary aim of the present investigation was to evaluate the levels of essential/toxic trace metals in the nails of non-Hodgkin and Hodgkin lymphomas patients in comparison with controls. The samples collected from patients and controls were digested in the mixture of HNO₃-HClO₄ and selected trace metals were analysed using flame atomic absorption spectrometry. The results showed that mean concentrations of some elements (Pb, Ni, Cd, Cu and Cr) in nails of non-Hodgkin lymphoma patients were significantly elevated (p < 0.05) than that of the controls whereas mean contents of Pb, Cu, Cd and Cr were observed to be significantly higher in the nails of Hodgkin lymphoma patients compared with healthy donors. Additionally, correlation study pointed out significantly diverse mutual associations of the trace metals among the patients and controls. The present results revealed noticeable disparities in the metal concentrations based on gender, food habits, tobacco use and types/stages of the donor's groups. Overall, the pathogenesis of disease significantly affected the trace metal balance in both patients' groups.

Biomarker selection and imaging design in cancer: A link with biochemical pathways for imminent engineering

Malignant cells reprogram metabolic pathways to meet the demands of growth and proliferation. These altered manners of metabolism are now identified as hallmarks of cancer. Studies have revealed tumor cells alter specific pathways such as glycolysis, fatty acid synthesis and amino acid synthesis to support their proliferation. In this review, we provide a theoretical framework to understand metabolic reprogramming and the mechanisms accompanying distorted metabolism to tumor progression. How these alterations will be assisting in cancer diagnostics and advances in standard techniques in marker identification and imagining are also discussed.

Trace Elements in Human Nutrition (II) - An Update

The dietary requirement for an essential trace element is an intake level which meets a specified criterion for adequacy and thereby minimizes risk of nutrient deficiency or excess. Disturbances in trace element homeostasis may result in the development of pathologic states and diseases. This article is an update of a review article “Trace Elements in Human Nutrition-A Review” previously published in 2013. The previous review was updated to emphasis in detail the importance of known trace elements so far in humans’ physiology and nutrition and also to implement the detailed information for practical and effective management of trace elements’ status in clinical diagnosis and health care situations. Although various classifications for trace elements have been proposed and may be controversial, this review will use World Health Organization( WHO) classification as previously done. For this review a traditional integrated review format was chosen and many recent medical and scientific literatures for the new findings on bioavailability, functions, and state of excess/deficiency of trace elements were assessed. The results indicated that for the known essential elements, essentiality and toxicity are unrelated and toxicity is a matter of dose or exposure. Little is known about the essentiality of some of the probably essential elements. In regard to toxic heavy metals, a toxic element may nevertheless be essential. In addition, the early pathological manifestations of trace elements deficiency or excess are difficult to detect until more specific pathologically relevant indicators become available. Discoveries and many refinements in the development of new techniques and continual improvement in laboratory methods have enabled researchers to detect the early pathological consequences of deficiency or excess of trace elements. They all are promises to fulfill the gaps in the present and future research and clinical diagnosis of trace elements deficiencies or intoxications. However, further investigations are needed to complete the important gaps in our knowledge on trace elements, especially probably essential trace elements’ role in health and disease status.

Alterations in ZnT1 expression and function lead to impaired intracellular zinc homeostasis in cancer

Zinc is vital for the structure and function of ~3000 human proteins and hence plays key physiological roles. Consequently, impaired zinc homeostasis is associated with various human diseases including cancer. Intracellular zinc levels are tightly regulated by two families of zinc transporters: ZIPs and ZnTs; ZIPs import zinc into the cytosol from the extracellular milieu, or from the lumen of organelles into the cytoplasm. In contrast, the vast majority of ZnTs compartmentalize zinc within organelles, whereas the ubiquitously expressed ZnT1 is the sole zinc exporter. Herein, we explored the hypothesis that qualitative and quantitative alterations in ZnT1 activity impair cellular zinc homeostasis in cancer. Towards this end, we first used bioinformatics to analyze inactivating mutations in ZIPs and ZNTs, catalogued in the COSMIC and gnomAD databases, representing tumor specimens and healthy population controls, respectively. ZnT1, ZnT10, ZIP8, and ZIP10 showed extremely high rates of loss of function mutations in cancer as compared to healthy controls. Analysis of the putative functional impact of missense mutations in ZnT1-ZnT10 and ZIP1-ZIP14, using homologous protein alignment and structural predictions, revealed that ZnT1 displays a markedly increased frequency of predicted functionally deleterious mutations in malignant tumors, as compared to a healthy population. Furthermore, examination of ZnT1 expression in 30 cancer types in the TCGA database revealed five tumor types with significant ZnT1 overexpression, which predicted dismal prognosis for cancer patient survival. Novel functional zinc transport assays, which allowed for the indirect measurement of cytosolic zinc levels, established that wild type ZnT1 overexpression results in low intracellular zinc levels. In contrast, overexpression of predicted deleterious ZnT1 missense mutations did not reduce intracellular zinc levels, validating eight missense mutations as loss of function (LoF) mutations. Thus, alterations in ZnT1 expression and LoF mutations in ZnT1 provide a molecular mechanism for impaired zinc homeostasis in cancer formation and/or progression.

Cooperation of endogenous and exogenous reactive oxygen species induced by zinc peroxide nanoparticles to enhance oxidative stress-based cancer therapy

Reactive oxygen species (ROS)-generating anticancer agents can act through two different mechanisms: (i) elevation of endogenous ROS production in mitochondria, or (ii) formation/delivery of exogenous ROS within cells. However, there is a lack of research on the development of ROS-generating nanosystems that combine endogenous and exogenous ROS to enhance oxidative stress-mediated cancer cell death. Methods: A ROS-generating agent based on polymer-modified zinc peroxide nanoparticles (ZnO2 NPs) was presented, which simultaneously delivered exogenous H2O2 and Zn2+ capable of amplifying endogenous ROS production for synergistic cancer therapy. Results: After internalization into tumor cells, ZnO2 NPs underwent decomposition in response to mild acidic pH, resulting in controlled release of H2O2 and Zn2+. Intriguingly, Zn2+ could increase the production of mitochondrial O2·- and H2O2 by inhibiting the electron transport chain, and thus exerted anticancer effect in a synergistic manner with the exogenously released H2O2 to promote cancer cell killing. Furthermore, ZnO2 NPs were doped with manganese via cation exchange, making them an activatable magnetic resonance imaging contrast agent. Conclusion: This study establishes a ZnO2-based theranostic nanoplatform which achieves enhanced oxidative damage to cancer cells by a two-pronged approach of combining endogenous and exogenous ROS.

Multifunctional Fe3O4@Polydopamine@DNA-Fueled Molecular Machine for Magnetically Targeted Intracellular Zn2+ Imaging and Fluorescence/MRI Guided Photodynamic-Photothermal Therapy

For the precise treatment of tumors, it is necessary to develop a theranostic nanoplatform that has both diagnostic and therapeutic functions. In this article, we designed a new theranostic probe for fluorescence imaging of Zn²⁺ and fluorescence/MRI guided magnetically targeted photodynamic-photothermal therapy. The fluorescence imaging of Zn²⁺ was based on an endogenous ATP-driven DNA nanomachine that could perform repetitive stand displacement reaction. It modifies all units on a single PDA/Fe₃O₄ nanoparticle containing a hairpin-locked initiated strand activated by a target molecule in cells, a two-stranded fuel DNA triggered by ATP, and a two-stranded DNA track responding to an initiated strand and fuel DNA. After entering the cell, the intracellular target Zn²⁺ initiates the nanomachine via an autocatalytic cleavage reaction, and the machine programmatically and gradually runs on the assembled DNA track via fuel DNA driving and the intramolecular toehold-mediated stand displacement reaction. The Fe₃O₄ core first exhibits magnetic targeting, increasing the ability of nanoparticles to enter tumor cells at the tumor site. The Fe₃O₄ could also be employed as a powerful magnetic resonance imaging (MRI) contrast agent and guided therapy. Using 808 nm laser and 635 nm laser irradiation together at the tumor site, the PDA nanoshell produced an excellent photothermal effect and the TMPyP4 molecules entering the cell generated reactive oxygen species, followed by cell damage. A series of reliable experiments suggested that the Fe₃O₄@PDA@DNA nanoprobe showed superior fluorescence specificity, MRI, a remarkable photothermal/photodynamic therapy effect, and favorable biocompatibility. This theranostic nanoplatform offered a split-new insight into tumor fluorescence and MRI diagnosis as well as effective tumor therapy.

Zinc promotes prostate cancer cell chemosensitivity to paclitaxel by inhibiting epithelial-mesenchymal transition and inducing apoptosis

BACKGROUND

Paclitaxel (PTX) is a first-line chemotherapeutic drug for the treatment of prostate cancer. However, most patients develop resistance and metastasis, and thus new therapeutic approaches are urgently required. Recent studies have identified widespread anti-tumor effects of zinc (Zn) in various tumor cell lines, especially prostate cancer cells. In this study, we examined the effects of Zn as an adjuvant to PTX in prostate cancer cells.

METHODS

PC3 and DU145 cells were treated with different concentrations of Zn and/or PTX. MTT assay was used to detect cell viability. Real-time cell analysis (RTCA) and microscopy were used to observe morphological changes in cells. Western blotting was used to detect the expression of epithelial-mesenchymal transition (EMT)-related proteins. qPCR (reverse transcription-polymerase chain reaction) was used to examine changes in TWIST1 mRNA levels. Cell invasion and migration were detected by scratch and transwell assays. shRNA against TWIST1 was used to knockdown TWIST1. Colony formation assay was used to detect cell proliferation, while Annexin V and propidium iodide (PI) staining was used to detect cell apoptosis.

RESULTS

Zn and PTX increased proliferation inhibition in a dose- and time-dependent manner in prostate cancer cells, while Zn increased prostate cancer cell chemosensitivity to PTX. Combined Zn and PTX inhibited prostate cancer cell invasion and migration by downregulating the expression of TWIST1. Furthermore, knockdown of TWIST1 increased the sensitivity of prostate cancer cells to PTX. In addition, Zn and PTX reduced cell proliferation and induced apoptosis in prostate cancer cells.

CONCLUSIONS

Our results demonstrated that Zn and PTX combined therapy inhibits EMT by reducing the expression of TWIST1, which reduces the invasion and migration of prostate cancer cells. SiTWIST1 increased the sensitivity of prostate cancer cells to PTX. In addition, with prolonged treatment, Zn and PTX inhibited proliferation and led to prostate cancer cell apoptosis. Therefore, Zn may be a potential adjuvant of PTX in treating prostate cancer and combined treatment may offer a promising therapeutic strategy for prostate cancer.