Zinc downregulates HIF-1α and inhibits its activity in tumor cells in vitro and in vivo

Targeting mineral metabolism in cancer: Insights into signaling pathways and therapeutic strategies

Cancer remains the second leading cause of death worldwide, emphasizing the critical need for effective treatment and control strategies. Essential minerals such as copper, iron, zinc, selenium, phosphorous, calcium, and magnesium are integral to various biological processes and significantly influence cancer progression through altered metabolic pathways. For example, dysregulated copper levels promote tumor growth, while cancer cells exhibit an increased dependency on iron for signaling and redox reactions. Zinc influences tumor development through pathways such as Akt-p21. Selenium, primarily through its role in selenoproteins, exhibits anticancer potential but may also contribute to tumor progression. Similarly, dietary phosphate exacerbates tumorigenesis, metastasis, and angiogenesis through signaling pathway activation. Calcium, the most abundant mineral in the body, is tightly regulated within cells, and its dysregulation is a hallmark of various cancers. Magnesium deficiency, on the other hand, promotes cancer progression by fostering inflammation and free radical-induced DNA mutations. Interestingly, magnesium also plays a dual role, with low levels enhancing epithelial-mesenchymal transition (EMT), a critical process in cancer metastasis. This complex interplay of essential minerals underscores their potential as therapeutic targets. Dysregulation of these minerals and their pathways could be exploited to selectively target cancer cells, offering novel therapeutic strategies. This review summarizes current research on the abnormal accumulation or depletion of these microelements in tumor biology, drawing evidence from animal models, cell lines, and clinical samples. We also highlight the potential of these minerals as biomarkers for cancer diagnosis and prognosis, as well as therapeutic approaches involving metal chelators, pharmacological agents, and nanotechnology. By highlighting the intricate roles of these minerals in cancer biology, we aim to inspire further research in this critical yet underexplored area of oncology.

Research progress of hypoxia-inducible factor-1α and zinc in the mechanism of diabetic kidney disease

Diabetic kidney disease is one of the common complications in diabetic patients and has gradually become an important pathogenic factor in chronic kidney disease. Therefore, studying the mechanisms of its occurrence and development is of great significance for the prevention and treatment of diabetic kidney disease. Some researchers have pointed out that there is a phenomenon of hypoxia in diabetic kidney tissue and believe that hypoxia-inducible factor-1α is closely related to the occurrence and progression of diabetic kidney disease. Additionally, the homeostasis of zinc plays a key role in the body's adaptation to hypoxic environments. However, the specific relationship among these three factors remains unclear. This article provides a detailed review of the multiple roles of hypoxia-inducible factor-1α in the pathogenesis of diabetic kidney disease, including: regulating angiogenesis, increasing the expression of erythropoietin, modulating oxidative stress through the PI3K/AKT and HIF-1α/HO-1 pathways, promoting inflammatory cell infiltration and the release of inflammatory factors to induce inflammatory responses, facilitating epithelial-mesenchymal transition, pathological angiogenesis, and promoting the release of fibrotic factors, ultimately leading to renal fibrosis. Furthermore, HIF-1α also participates in the occurrence and development of diabetic kidney disease through mechanisms such as regulating apoptosis, inducing mitochondrial autophagy, and vascular calcification. At the same time, this article clarifies the regulatory role of the trace element zinc on hypoxia-inducible factor-1α in diabetic kidney disease. This article provides references and insights for further research on the pathogenesis and progression of diabetic kidney disease.

The role of HIF-1α/BNIP3/mitophagy in acrylonitrile-induced neuronal death in HT22 cells and mice: A potential neuroprotection target

Acrylonitrile (AN) is a widely utilized organic compound in the production of diverse industrial synthetic materials. While acute exposure to AN can cause neurotoxicity, the precise mechanism remains unclear. Hypoxia-inducible factor 1 alpha (HIF-1α) is a pivotal transcription factor that coordinates and orchestrates multiple physiological processes to adapt to hypoxic conditions, ensuring cellular survival and homeostasis. In this study, we used in vitro (cultured mouse hippocampal neuronal cell line, HT22) and in vivo (AN exposed mice) approaches to investigate the potential modulator effects of HIF-1α in AN-induced neurotoxicity. In vitro, AN exposure caused concentration-dependent toxicity in HT22 cells, which was paralleled by increased Bax levels while decreasing Bcl-2. Exposure to AN resulted in reduced protein levels of HIF-1α, Bcl-2 19-kDa interacting protein 3 (BNIP3), microtubule-associated protein 1 light chain 3 beta (LC3B) and Beclin1, while increased the protein levels of the translocase of outer mitochondrial membrane 20 (TOM20). Furthermore, mitochondrial morphology and function were compromised, suggesting that AN impaired HIF-1α/BNIP3-mediated mitochondrial autophagy and promoted apoptosis. Treatment with a HIF-1α activator, cobalt chloride (CoCl2), reversed these effects, while pretreatment with a HIF-1α inhibitor, 2-methoxyestradiol (2-MeOE2), augmented them. In BNIP3 overexpressing HT22 cells, enhanced cell viability and reduced apoptosis rates were observed. Furthermore, the HIF-1α/BNIP3 pathway was activated by the prolyl hydroxylase (PHD2) inhibitor, deferoxamine (DFO), which increased HT22 cell viability. Similarly, the activation of HIF-1α by administering 20 mg/kg of CoCl2 was found to alleviate neurotoxicity in mice. This treatment enhanced elevations of autophagy protein expression and co-localization of BNIP3 and LC3B. In summary, under normoxia, AN induced neurotoxicity by promoting PHD2-mediated HIF-1α degradation, disrupted the BNIP3-mediated mitophagy pathway, and enhanced apoptosis. Our findings underscore the effect of the HIF-1α/BNIP3-mediated mitochondrial autophagy in AN-induced neurotoxicity and suggest potential therapeutic strategies involving HIF-1α activation or BNIP3 overexpression for AN poisoning treatment.

Review Article on Molecular Basis of Zinc and Copper Interactions in Cancer Physiology

Various clinical manifestations associated with measurable abnormalities of Zn and Cu in serum and tissue were determined in Cancer-Patients (CP), and therefore, these two metals are drawing more and more attention presently than ever before. Cancer is a disease of uncontrolled-abnormal-cell-division with invasion-potential which was exhibited to occur due to dys-regulation/dys-homeostasis of fundamental-biological-pathways (FBP) including antioxidant-enzyme-defense-system, anti-inflammatory and immune-systems, and DNA-damage-repair-system in the human-body resulting in generation of chronic-oxidative-stress induced DNA-damage and gene-mutations, inflammation and compromised immune-system, tumor-induced increased angiogenesis, and inhibition of apoptosis processes. Zn and Cu were recognized to be the most crucial components of FBP and imbalance in Zn/Cu ratios in CP asserted to generate chronic toxicity in human body through various mechanisms including increased chronic oxidative stress linked compromised DNA integrity and gene mutations due to malfunctioning of DNA damage repair enzymes; increased angiogenesis process due to Zn- and Cu-binding proteins metallothionein and ceruloplasmin-induced enhanced expression of tumor growth factors; and elevation in inflammatory response which was further shown to down/upregulate gene expression of multiple Zn transporter proteins leading to dys-homeostasis of intracellular Zn concentrations, and it was determined to disturb the equilibrium between cell growth and division, proliferation, differentiation, and apoptosis processes which lead to cancer progression. Moreover, Zn was reported to affect matrix metalloproteinase activity and influence immune system cells to respond differently to different cytokines and enhance immune-suppressive effects accelerating the angiogenesis, invasion, and metastasis potential in cancer. Further, the most significant use of serum Cu/Zn ratio was recommended in clinical diagnosis, prognosis, tumor stage, patient survival, and cancer follow-up studies which need further investigations to elucidate and explore their roles in cancer physiology for clinical perspective.

HIPK2 in Colon Cancer: A Potential Biomarker for Tumor Progression and Response to Therapies

Colon cancer, one of the most common and fatal cancers worldwide, is characterized by stepwise accumulation of specific genetic alterations in tumor suppressor genes or oncogenes, leading to tumor growth and metastasis. HIPK2 (homeodomain-interacting protein kinase 2) is a serine/threonine protein kinase and a "bona fide" oncosuppressor protein. Its activation inhibits tumor growth mainly by promoting apoptosis, while its inactivation increases tumorigenicity and resistance to therapies of many different cancer types, including colon cancer. HIPK2 interacts with many molecular pathways by means of its kinase activity or transcriptional co-repressor function modulating cell growth and apoptosis, invasion, angiogenesis, inflammation and hypoxia. HIPK2 has been shown to participate in several molecular pathways involved in colon cancer including p53, Wnt/β-catenin and the newly identified nuclear factor erythroid 2 (NF-E2) p45-related factor 2 (NRF2). HIPK2 also plays a role in tumor-host interaction in the tumor microenvironment (TME) by inducing angiogenesis and cancer-associated fibroblast (CAF) differentiation. The aim of this review is to assess the role of HIPK2 in colon cancer and the underlying molecular pathways for a better understanding of its involvement in colon cancer carcinogenesis and response to therapies, which will likely pave the way for novel colon cancer therapies.

Understanding the Significance of Hypoxia-Inducible Factors (HIFs) in Glioblastoma: A Systematic Review

BACKGROUND

The study aims to investigate the role of hypoxia-inducible factors (HIFs) in the development, progression, and therapeutic potential of glioblastomas.

METHODOLOGY

The study, following PRISMA guidelines, systematically examined hypoxia and HIFs in glioblastoma using MEDLINE (PubMed), Web of Science, and Scopus. A total of 104 relevant studies underwent data extraction.

RESULTS

Among the 104 studies, global contributions were diverse, with China leading at 23.1%. The most productive year was 2019, accounting for 11.5%. Hypoxia-inducible factor 1 alpha (HIF1α) was frequently studied, followed by hypoxia-inducible factor 2 alpha (HIF2α), osteopontin, and cavolin-1. Commonly associated factors and pathways include glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3) receptors, vascular endothelial growth factor (VEGF), phosphoinositide 3-kinase (PI3K)-Akt-mechanistic target of rapamycin (mTOR) pathway, and reactive oxygen species (ROS). HIF expression correlates with various glioblastoma hallmarks, including progression, survival, neovascularization, glucose metabolism, migration, and invasion.

CONCLUSION

Overcoming challenges such as treatment resistance and the absence of biomarkers is critical for the effective integration of HIF-related therapies into the treatment of glioblastoma with the aim of optimizing patient outcomes.

Zinc based biodegradable metals for bone repair and regeneration: Bioactivity and molecular mechanisms

Bone fractures and critical-size bone defects are significant public health issues, and clinical treatment outcomes are closely related to the intrinsic properties of the utilized implant materials. Zinc (Zn)-based biodegradable metals (BMs) have emerged as promising bioactive materials because of their exceptional biocompatibility, appropriate mechanical properties, and controllable biodegradation. This review summarizes the state of the art in terms of Zn-based metals for bone repair and regeneration, focusing on bridging the gap between biological mechanism and required bioactivity. The molecular mechanism underlying the release of Zn ions from Zn-based BMs in the improvement of bone repair and regeneration is elucidated. By integrating clinical considerations and the specific bioactivity required for implant materials, this review summarizes the current research status of Zn-based internal fixation materials for promoting fracture healing, Zn-based scaffolds for regenerating critical-size bone defects, and Zn-based barrier membranes for reconstituting alveolar bone defects. Considering the significant progress made in the research on Zn-based BMs for potential clinical applications, the challenges and promising research directions are proposed and discussed.

Zinc Supplementation Enhances the Hematopoietic Activity of Erythropoiesis-Stimulating Agents but Not Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitors

Since zinc is involved in many aspects of the hematopoietic process, zinc supplementation can reduce erythropoiesis-stimulating agents (ESAs) in patients undergoing hemodialysis. However, it remains unclear whether hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) have similar reduction effects. HIF-PHI stabilizes HIF, which promotes hematopoiesis, although HIF-1α levels are downregulated by zinc. This study aimed to investigate the effect of zinc supplementation on the hematopoietic effect of HIF-PHI in patients undergoing hemodialysis. Thirty patients undergoing maintenance hemodialysis who underwent periods of treatment with roxadustat or darbepoetin alfa during the past 3 years were retrospectively observed. Participants who underwent periods with and without zinc supplementation were selected, with nine treated with darbepoetin alfa and nine treated with roxadustat. Similarly to the ESA responsiveness index (ERI), the hematopoietic effect of zinc supplementation was determined by the HIF-PHI responsiveness index (HRI), which was calculated by dividing the HIF-PHI dose (mg/week) by the patient's dry weight (kg) and hemoglobin level (g/L). Zinc supplementation significantly increased ERI (p < 0.05), but no significant change was observed (p = 0.931) in HRI. Although zinc supplementation did not significantly affect HRI, adequate zinc supplementation is required to alleviate concerns such as vascular calcification and increased serum copper during the use of HIF-PHI.

Current Trends on the Involvement of Zinc, Copper, and Selenium in the Process of Hepatocarcinogenesis

Numerous nutritional factors increase the risk of hepatocellular carcinoma (HCC) development. The dysregulation of zinc, copper, and selenium homeostasis is associated with the occurrence of HCC. The impairment of the homeostasis of these essential trace elements results in oxidative stress, DNA damage, cell cycle progression, and angiogenesis, finally leading to hepatocarcinogenesis. These essential trace elements can affect the microenvironment in HCC. The carrier proteins for zinc and copper and selenium-containing enzymes play important roles in the prevention or progression of HCC. These trace elements enhance or alleviate the chemosensitivity of anticancer agents in patients with HCC. The zinc, copper, or selenium may affect the homeostasis of other trace elements with each other. Novel types of cell death including ferropotosis and cupropotosis are also associated with hepatocarcinogenesis. Therapeutic strategies for HCC that target these carrier proteins for zinc and copper or selenium-containing enzymes have been developed in in vitro and in vivo studies. The use of zinc-, copper- or selenium-nanoparticles has been considered as novel therapeutic agents for HCC. These results indicate that zinc, copper, and selenium may become promising therapeutic targets in patients with HCC. The clinical application of these agents is an urgent unmet requirement. This review article highlights the correlation between the dysregulation of the homeostasis of these essential trace elements and the development of HCC and summarizes the current trends on the roles of these essential trace elements in the pathogenesis of hepatocarcinogenesis.

Cellular zinc metabolism and zinc signaling: from biological functions to diseases and therapeutic targets

Zinc metabolism at the cellular level is critical for many biological processes in the body. A key observation is the disruption of cellular homeostasis, often coinciding with disease progression. As an essential factor in maintaining cellular equilibrium, cellular zinc has been increasingly spotlighted in the context of disease development. Extensive research suggests zinc's involvement in promoting malignancy and invasion in cancer cells, despite its low tissue concentration. This has led to a growing body of literature investigating zinc's cellular metabolism, particularly the functions of zinc transporters and storage mechanisms during cancer progression. Zinc transportation is under the control of two major transporter families: SLC30 (ZnT) for the excretion of zinc and SLC39 (ZIP) for the zinc intake. Additionally, the storage of this essential element is predominantly mediated by metallothioneins (MTs). This review consolidates knowledge on the critical functions of cellular zinc signaling and underscores potential molecular pathways linking zinc metabolism to disease progression, with a special focus on cancer. We also compile a summary of clinical trials involving zinc ions. Given the main localization of zinc transporters at the cell membrane, the potential for targeted therapies, including small molecules and monoclonal antibodies, offers promising avenues for future exploration.

A hypothesis: Potential contributions of metals to the pathogenesis of pulmonary artery hypertension

Pulmonary artery hypertension (PAH) is characterized by vasoconstriction and vascular remodeling resulting in both increased pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP). The chronic and high-pressure stress experienced by endothelial cells can give rise to inflammation, oxidative stress, and infiltration by immune cells. However, there is no clearly defined mechanism for PAH and available treatment options only provide limited symptomatic relief. Due to the far-reaching effects of metal exposures, the interaction between metals and the pulmonary vasculature is of particular interest. This review will briefly introduce the pathophysiology of PAH and then focus on the potential roles of metals, including essential and non-essential metals in the pathogenic process in the pulmonary arteries and right heart, which may be linked to PAH. Based on available data from human studies of occupational or environmental metal exposure, including lead, antimony, iron, and copper, the hypothesis of metals contributing to the pathogenesis of PAH is proposed as potential risk factors and underlying mechanisms for PAH. We propose that metals may initiate or exacerbate the pathogenesis of PAH, by providing potential mechanism by which metals interact with hypoxia-inducible factor and tumor suppressor p53 to modulate their downstream cellular proliferation pathways. These need further investigation. Additionally, we present future research directions on roles of metals in PAH.

Therapeutic Targeting of Glioblastoma and the Interactions with Its Microenvironment

Glioblastoma (GBM) is the most common primary malignant brain tumour, and it confers a dismal prognosis despite intensive multimodal treatments. Whilst historically, research has focussed on the evolution of GBM tumour cells themselves, there is growing recognition of the importance of studying the tumour microenvironment (TME). Improved characterisation of the interaction between GBM cells and the TME has led to a better understanding of therapeutic resistance and the identification of potential targets to block these escape mechanisms. This review describes the network of cells within the TME and proposes treatment strategies for simultaneously targeting GBM cells, the surrounding immune cells, and the crosstalk between them.

Transition metals in angiogenesis - A narrative review

The aim of this paper is to offer a narrative review of the literature regarding the influence of transition metals on angiogenesis, excluding lanthanides and actinides. To our knowledge there are not any reviews up to date offering such a summary, which inclined us to write this paper. Angiogenesis describes the process of blood vessel formation, which is an essential requirement for human growth and development. When the complex interplay between pro- and antiangiogenic mediators falls out of balance, angiogenesis can quickly become harmful. As it is so fundamental, both its inhibition and enhancement take part in various diseases, making it a target for therapeutic treatments. Current methods come with limitations, therefore, novel agents are constantly being researched, with metal agents offering promising results. Various transition metals have already been investigated in-depth, with studies indicating both pro- and antiangiogenic properties, respectively. The transition metals are being applied in various formulations, such as nanoparticles, complexes, or scaffold materials. Albeit the increasing attention this field is receiving, there remain many unanswered questions, mostly regarding the molecular mechanisms behind the observed effects. Notably, approximately half of all the transition metals have not yet been investigated regarding potential angiogenic effects. Considering the promising results which have already been established, it should be of great interest to begin investigating the remaining elements whilst also further analyzing the established effects.

Zinc enhances the cell adhesion, migration, and self-renewal potential of human umbilical cord derived mesenchymal stem cells

BACKGROUND

Zinc (Zn) is the second most abundant trace element after Fe, present in the human body. It is frequently reported in association with cell growth and proliferation, and its deficiency is considered to be a major disease contributing factor.

AIM

To determine the effect of Zn on in vitro growth and proliferation of human umbilical cord (hUC)-derived mesenchymal stem cells (MSCs).

METHODS

hUC-MSCs were isolated from human umbilical cord tissue and characterized based on immunocytochemistry, immunophenotyping, and tri-lineage differentiation. The impact of Zn on cytotoxicity and proliferation was determined by MTT and Alamar blue assay. To determine the effect of Zn on population doubling time (PDT), hUC-MSCs were cultured in media with and without Zn for several passages. An in vitro scratch assay was performed to analyze the effect of Zn on the wound healing and migration capability of hUC-MSCs. A cell adhesion assay was used to test the surface adhesiveness of hUC-MSCs. Transcriptional analysis of genes involved in the cell cycle, proliferation, migration, and self-renewal of hUC-MSCs was performed by quantitative real-time polymerase chain reaction. The protein expression of Lin28, a pluripotency marker, was analyzed by immunocytochemistry.

RESULTS

Zn at lower concentrations enhanced the rate of proliferation but at higher concentrations (> 100 µM), showed concentration dependent cytotoxicity in hUC-MSCs. hUC-MSCs treated with Zn exhibited a significantly greater healing and migration rate compared to untreated cells. Zn also increased the cell adhesion rate, and colony forming efficiency (CFE). In addition, Zn upregulated the expression of genes involved in the cell cycle (CDC20, CDK1, CCNA2, CDCA2), proliferation (transforming growth factor β1, GDF5, hypoxia-inducible factor 1α), migration (CXCR4, VCAM1, VEGF-A), and self-renewal (OCT4, SOX2, NANOG) of hUC-MSCs. Expression of Lin28 protein was significantly increased in cells treated with Zn.

CONCLUSION

Our findings suggest that zinc enhances the proliferation rate of hUC-MSCs decreasing the PDT, and maintaining the CFE. Zn also enhances the cell adhesion, migration, and self-renewal of hUC-MSCs. These results highlight the essential role of Zn in cell growth and development.

The Sweet Side of HIPK2

HIPK2 is an evolutionary conserved protein kinase which modulates many molecular pathways involved in cellular functions such as apoptosis, DNA damage response, protein stability, and protein transcription. HIPK2 plays a key role in the cancer cell response to cytotoxic drugs as its deregulation impairs drug-induced cancer cell death. HIPK2 has also been involved in regulating fibrosis, angiogenesis, and neurological diseases. Recently, hyperglycemia was found to positively and/or negatively regulate HIPK2 activity, affecting not only cancer cell response to chemotherapy but also the progression of some diabetes complications. The present review will discuss how HIPK2 may be influenced by the high glucose (HG) metabolic condition and the consequences of such regulation in medical conditions.

Therapeutic actions of tea phenolic compounds against oxidative stress and inflammation as central mediators in the development and progression of health problems: A review focusing on microRNA regulation

Many health problems including chronic diseases are closely associated with oxidative stress and inflammation. Tea has abundant phenolic compounds with various health benefits including antioxidant and anti-inflammatory properties. This review focuses on the present understanding of the impact of tea phenolic compounds on the expression of miRNAs, and elucidates the biochemical and molecular mechanisms underlying the transcriptional and post-transcriptional protective actions of tea phenolic compounds against oxidative stress- and/or inflammation-mediated diseases. Clinical studies showed that drinking tea or taking catechin supplement on a daily basis promoted the endogenous antioxidant defense system of the body while inhibiting inflammatory factors. The regulation of chronic diseases based on epigenetic mechanisms, and the epigenetic-based therapies involving different tea phenolic compounds, have been insufficiently studied. The molecular mechanisms and application strategies of miR-27 and miR-34 involved in oxidative stress response and miR-126 and miR-146 involved in inflammation process were preliminarily investigated. Some emerging evidence suggests that tea phenolic compounds may promote epigenetic changes, involving non-coding RNA regulation, DNA methylation, histone modification, ubiquitin and SUMO modifications. However, epigenetic mechanisms and epigenetic-based disease therapies involving phenolic compounds from different teas, and the potential cross-talks among the epigenetic events, remain understudied.

The role of hypoxia-inducible factor 1 alpha (HIF-1α) modulation in heavy metal toxicity

Hypoxia-inducible factor 1 (HIF-1) is an oxygen-sensing transcriptional regulator orchestrating a complex of adaptive cellular responses to hypoxia. Several studies have demonstrated that toxic metal exposure may also modulate HIF-1α signal transduction pathway, although the existing data are scarce. Therefore, the present review aims to summarize the existing data on the effects of toxic metals on HIF-1 signaling and the potential underlying mechanisms with a special focus on prooxidant effect of the metals. The particular effect of metals was shown to be dependent on cell type, varying from down- to up-regulation of HIF-1 pathway. Inhibition of HIF-1 signaling may contribute to impaired hypoxic tolerance and adaptation, thus promoting hypoxic damage in the cells. In contrast, its metal-induced activation may result in increased tolerance to hypoxia through increased angiogenesis, thus promoting tumor growth and contributing to carcinogenic effect of heavy metals. Up-regulation of HIF-1 signaling is mainly observed upon Cr, As, and Ni exposure, whereas Cd and Hg may both stimulate and inhibit HIF-1 pathway. The mechanisms underlying the influence of toxic metal exposure on HIF-1 signaling involve modulation of prolyl hydroxylases (PHD2) activity, as well as interference with other tightly related pathways including Nrf2, PI3K/Akt, NF-κB, and MAPK signaling. These effects are at least partially mediated by metal-induced ROS generation. Hypothetically, maintenance of adequate HIF-1 signaling upon toxic metal exposure through direct (PHD2 modulation) or indirect (antioxidant) mechanisms may provide an additional strategy for prevention of adverse effects of metal toxicity.

HIPK2 in Angiogenesis: A Promising Biomarker in Cancer Progression and in Angiogenic Diseases

Angiogenesis is the formation of new blood capillaries taking place from preexisting functional vessels, a process that allows cells to cope with shortage of nutrients and low oxygen availability. Angiogenesis may be activated in several pathological diseases, from tumor growth and metastases formation to ischemic and inflammatory diseases. New insights into the mechanisms that regulate angiogenesis have been discovered in the last years, leading to the discovery of new therapeutic opportunities. However, in the case of cancer, their success may be limited by the occurrence of drug resistance, meaning that the road to optimize such treatments is still long. Homeodomain-interacting protein kinase 2 (HIPK2), a multifaceted protein that regulates different molecular pathways, is involved in the negative regulation of cancer growth, and may be considered a "bona fide" oncosuppressor molecule. In this review, we will discuss the emerging link between HIPK2 and angiogenesis and how the control of angiogenesis by HIPK2 impinges in the pathogenesis of several diseases, including cancer.

FBXO30 functions as a tumor suppressor and an E3 ubiquitin ligase for hZIP1‑mediated HIF‑1α degradation in renal cell carcinoma

Studies on clear cell renal cell carcinoma (ccRCC) are gaining momentum due to its high malignancy and potential to metastasize. F‑box protein 30 (FBXO30) is a member of the F‑box protein family; however, its role and mechanism in cancer remains to be fully elucidated. Western blotting, reverse transcription‑quantitative PCR and immunohistochemsitry were performed to detect the expression levels of FBXO30 in ccRCC tissues and adjacent normal tissues. Tumor biological function assays and animal experiments were conducted to clarify the inhibitory effect of FBXO30 on the progression and metastasis of ccRCC. Protein half‑life assay, MG132 inhibition assay, immunofluorescence assay and co‑immunoprecipitation assay were performed to explore the ubiquitination mechanism of FBXO30 and HIF‑1α. Zinc supplementation assay was used to verify the regulatory relationship between human ZRT, IRT‑like protein 1 (hZIP1), FBXO30 and HIF‑1α. The present study revealed that the expression levels of FBXO30 were lower in ccRCC tissues compared with those in normal adjacent tissues. In addition, FBXO30 inhibited the tumorigenesis and metastatic capacity of ccRCC cells in vivo and in vitro. FBXO30 mediated the ubiquitination and degradation of hypoxia‑inducible factor‑1α (HIF‑1α) in ccRCC cells under normoxia, thereby inhibiting the oncogenic effect of HIF‑1α. Notably, hZIP1 served as an upstream regulator of FBXO30, regulating the expression of FBXO30 and HIF‑1α by recruiting Zn²⁺. In conclusion, the present data suggested that FBXO30 is a novel E3 ubiquitination ligase that can function as a tumor suppressor in ccRCC, and the hZIP1/Zn²⁺/FBXO30/HIF‑1α axis may provide potential biomarkers or therapeutic targets for ccRCC.

The Relationship Between Zinc Deficiency and Hepatocellular Carcinoma Associated with Hepatitis B Liver Cirrhosis: A 10-year Follow-up Study

Our aim is to evaluate the serum zinc levels in Hepatitis B liver cirrhosis patients and clarify the relationship between the serum zinc levels and the development of hepatocellular carcinoma (HCC). From January 2009 to December 2019, 295 included patients diagnosed with Hepatitis B liver cirrhosis received nucleos(t)ide analogues (NUCs) therapy at China-Japan Union Hospital of Jilin University. Their comprehensive medical records were retrospectively analyzed, and to analyze the relationship between hypozincemia and hepatitis B-related HCC. Twenty-eight of 295 patients (9.49%) developed HCC during an observation period of the median follow-up time was 42 months. Compared with the non-zinc deficiency group, the zinc deficiency group is older, has a higher proportion of hepatic encephalopathy, higher levels of aspartate aminotransferase(AST), international normalized ratio(INR) and TB, and lower levels of cholinesterase (CHE), creatinine, and platelet counts (P< 0.05). Multivariate analysis showed that zine (HR=0.854, 95%CI 0.725-1.007; P=0.061), zinc is not significant for reducing the incidence of HCC, as liver disease progresses, the proportion of zinc deficiency is getting higher and higher, Child-Pugh C. The proportion of grade zinc deficiency accounted for 64.86%. Child-Pugh grade C was more than Child-Pugh grade B and A, p<0.001. Zinc deficiency is associated with hepatic encephalopathy, and other complications related to hepatitis B and liver cirrhosis. But the relationship with hepatocellular carcinoma still needs further study.

ZnT2 Is Critical for TLR4-Mediated Cytokine Expression in Colonocytes and Modulates Mucosal Inflammation in Mice

A wide range of microbial pathogens can enter the gastrointestinal tract, causing mucosal inflammation and infectious colitis and accounting for most cases of acute diarrhea. Severe cases of infectious colitis can persist for weeks, and if untreated, may lead to major complications and death. While the molecular pathogenesis of microbial infections is often well-characterized, host-associated epithelial factors that affect risk and severity of infectious colitis are less well-understood. The current study characterized functions of the zinc (Zn) transporter ZnT2 (SLC30A2) in cultured HT29 colonocytes and determined consequences of ZnT2 deletion in mice on the colonic response to enteric infection with Citrobacter rodentium. ZnT2 in colonocytes transported Zn into vesicles buffering cytoplasmic Zn pools, which was important for Toll-like receptor 4 (TLR4) expression, activation of pathogen-stimulated NF-κβ translocation and cytokine expression. Additionally, ZnT2 was critical for lysosome biogenesis and bacterial-induced autophagy, both promoting robust host defense and resolution mechanisms in response to enteric pathogens. These findings reveal that ZnT2 is a novel regulator of mucosal inflammation in colonocytes and is critical to the response to infectious colitis, suggesting that manipulating the function of ZnT2 may offer new therapeutic strategies to treat specific intestinal infections.

Antitumor Effect of Zinc Acetate in Hepatocellular Carcinoma Cell Lines via the Induction of Apoptosis

We aimed to verify antitumor effects of zinc acetate on hepatocellular carcinoma (HCC) in vitro. Five HCC cell lines (HepG2, Hep3B, Huh7, HLE and Alex) were used to evaluate the antitumor effects of zinc acetate. Cell viability was determined by the Cell Counting Kit-8 assay. The cell-cycle alteration was evaluated by a flow cytometric analysis and the detection of cell cycle-related proteins. Apoptosis was determined based on the caspase-cleaved cytokeratin 18 (cCK18) levels. The microRNAs (miRNAs) related to an antitumor effect of zinc acetate were identified using microarrays. Zinc acetate significantly inhibited the proliferation of HCC cells in a dose-dependent manner. The treatment with zinc acetate resulted in significantly increased cCK18 levels in the supernatant and enhanced the expression of heme oxygenase-1 (HO-1) in HCC cells. The flow cytometric analysis revealed an increase of HCC cells in the S and G₂/M phases by the administration of zinc acetate, and the expressions of Cdk2 and cyclin E were increased. The miRNA expression profile of the HCC cells treated with zinc acetate was extremely different from that of the untreated HCC cells. These results suggest that the zinc acetate supplementation induces the apoptosis of HCC cells, but does not affect the cell cycle progression. Upregulation of HO-1 and the alteration of miRNAs' profile may be involved in antitumor effects of zinc acetate in HCC cells.

Cellular mechanisms of biodegradable zinc and magnesium materials on promoting angiogenesis

Biodegradable metals, zinc and magnesium, have been regarded as next-generation, biomedical implant materials to promote tissue repair and regeneration. These implants might also promote the vascularization of surrounding neotissue. Released metallic ions, Zn²⁺ and Mg²⁺, show promise in vitro to implement vessel growth by stimulating the expression of pro-angiogenic cytokines, yet there is little known regarding how cellular responses transcend to influence the tissue environment. This study serves to optimize angiogenic behavior using EA.hy926 endothelial cultures exposed to Zn²⁺ and Mg²⁺ gradients and observe the translation of these effects on blood vessel development via the in ovo chorioallantoic membrane (CAM) assay. Findings indicate that Zn²⁺ 10 μM and Mg²⁺ 10 mM instigate the most prominent effects using endothelial cultures via scratch wound and tube formation assays, yet higher concentrations at Zn²⁺ 50 μM and Mg²⁺ 50 mM encourage significant angiogenesis along the CAM. Immunoblotting results also conclude the presence and upregulation of cytokines involved in vessel growth. Optimizing the angiogenic potential of Zn²⁺ and Mg²⁺ separately sheds light to design future engineering constructs for promoting blood vessel development and successful assimilation between host and implant tissue.

Immune-regulating strategy against rheumatoid arthritis by inducing tolerogenic dendritic cells with modified zinc peroxide nanoparticles

In hypoxic dendritic cells (DCs), a low level of Zn²⁺ can induce the activation of immunogenic DCs (igDCs), thereby triggering an active T-cell response to propel the immune progression of rheumatoid arthritis (RA). This finding indicates the crucial roles of zinc and oxygen homeostasis in DCs during the pathogenesis of RA. However, very few studies have focused on the modulation of zinc and oxygen homeostasis in DCs during RA treatment. Proposed herein is a DC-targeting immune-regulating strategy to induce igDCs into tolerogenic DCs (tDCs) and inhibit subsequent T-cell activation, referred to as ZnO₂/Catalase@liposome-Mannose nanoparticles (ZnCM NPs). ZnCM NPs displayed targeted intracellular delivery of Zn²⁺ and O₂ towards igDCs in a pH-responsive manner. After inactivating OTUB1 deubiquitination, the ZnCM NPs promoted CCL5 degradation via NF-κB signalling, thereby inducing the igDC-tDC transition to further inhibit CD4⁺ T-cell homeostasis. In collagen-induced arthritis (CIA) mice, this nanoimmunoplatform showed significant accumulation in the spleen, where immature DCs (imDCs) differentiated into igDCs. Splenic tDCs were induced to alleviate ankle swelling, improve walking posture and safely inhibit ankle/spleen inflammation. Our work pioneers the combination of DC-targeting nanoplatforms with RA treatments and highlights the significance of zinc and oxygen homeostasis for the immunoregulation of RA by inducing tDCs with modified ZnO₂ NPs, which provides novel insight into ion homeostasis regulation for the treatment of immune diseases with a larger variety of distinct metal or nonmetal ions.

The DC-targeting immune-regulating nanostrategy was firstly employed to treat RA.

The complex immune regulating effects was realized through a portable, convenient and green nanomaterial.

Highlighting the significance of zinc and oxygen homeostasis for the immunoregulation of RA by inducing tDCs with modified ZnO₂ NPs.

Expanding the notion of ion homeostasis regulation with a larger variety of distinct metal or nonmetal ions.

Regenerative Activities of ROS-Modulating Trace Metals in Subcutaneously Implanted Biodegradable Cryogel

Divalent trace metals (TM), especially copper (Cu), cobalt (Co) and zinc (Zn), are recognized as essential microelements for tissue homeostasis and regeneration. To achieve a balance between therapeutic activity and safety of administered TMs, effective gel formulations of TMs with elucidated regenerative mechanisms are required. We studied in vitro and in vivo effects of biodegradable macroporous cryogels doped with Cu, Co or Zn in a controllable manner. The extracellular ROS generation by metal dopants was assessed and compared with the intracellular effect of soluble TMs. The stimulating ability of TMs in the cryogels for cell proliferation, differentiation and cytokine/growth factor biosynthesis was characterized using HSF and HUVEC primary human cells. Multiple responses of host tissues to the TM-doped cryogels upon subcutaneous implantation were characterized taking into account the rate of biodegradation, production of HIF-1α/matrix metalloproteinases and the appearance of immune cells. Cu and Zn dopants did not disturb the intact skin organization while inducing specific stimulating effects on different skin structures, including vasculature, whereas Co dopant caused a significant reorganization of skin layers, the appearance of multinucleated giant cells, along with intense angiogenesis in the dermis. The results specify and compare the prooxidant and regenerative potential of Cu, Co and Zn-doped biodegradable cryogels and are of particular interest for the development of advanced bioinductive hydrogel materials for controlling angiogenesis and soft tissue growth.

ZIP12 Contributes to Hypoxic Pulmonary Hypertension by Driving Phenotypic Switching of Pulmonary Artery Smooth Muscle Cells

ABSTRACT

ZIP12, a plasmalemmal zinc transporter, reportedly promotes pulmonary vascular remodeling (PVR) by enhancing proliferation of pulmonary artery smooth muscle cells (PASMCs). However, the mechanisms of ZIP12 facilitating PASMCs proliferation remain incompletely appreciated. It has been acknowledged that proliferation-predisposing phenotypic switching of PASMCs can lead to PVR. Given that hypoxia triggers phenotypic switching of PASMCs and ZIP12 mediates PVR, this study aims to explore whether ZIP12-mediated phenotypic switching of PASMCs contributes to hypoxia-induced PVR. Rats were exposed to hypoxia (10% O2) for 3 weeks to induce PVR, and primary rat PASMCs were cultured under hypoxic condition (3% O2) for 48 hours to induce proliferation. Immunofluorescence, quantitative reverse transcription-polymerase chain reaction, and Western blot analysis were performed to detect the expression of target mRNAs and proteins. EdU incorporation and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay were conducted to measure the proliferation of PASMCs. Hypoxia upregulated ZIP12 expression (both mRNA and protein) in pulmonary arteries and PASMCs. Knockdown of ZIP12 inhibited phenotypic switching of PASMCs induced by hypoxia. We propose that HIF-1α/ZIP12/pERK pathway could represent a novel mechanism underlying hypoxia-induced phenotypic switching of PASMCs. Therapeutic targeting of ZIP12 could be exploited to treat PVR.

hZIP1 Inhibits Progression of Clear Cell Renal Cell Carcinoma by Suppressing NF-kB/HIF-1α Pathway

Purpose

Accumulating literature has suggested that hZIP1 and HIF-1α play vital roles in the tumor process of clear cell renal cell carcinoma (ccRCC). However, the functional roles of hZIP1 and HIF-1α in ccRCC remain largely unknown.

Methods

HIF-1α protein level was evaluated by a western blot in ccRCC tissues and cell lines. ccRCC cell lines were transfected with HIF-1α-siRNA to downregulate the expression level of HIF-1α. Then the proliferative, migratory and invasive abilities of ccRCC cells in vitro were detected by real-time cell analysis (RTCA) assay, wound healing assay and transwell assay, respectively. The role of HIF-1α in vivo was explored by tumor implantation in nude mice. Then the effect on glycolysis‐related proteins was performed by western blot after hZIP1 knockdown (overexpression) or HIF-1α knockdown. The effect on NF‐kB pathway was detected after hZIP1 overexpression.

Results

HIF-1α was markedly downregulated in ccRCC tissues compared with normal areas. But HIF-1α presented almost no expression in HK-2 and ACHN cells. Immunofluorescence indicated HIF-1α and PDK1 expression in both the cytoplasm and nucleus in ccRCC cells. Downregulation of HIF-1α suppressed ccRCC cell proliferation, migration, and invasion and resulted in smaller implanted tumors in nude mice. Furthermore, hZIP1 knockdown elevated HIF-1α protein levels and PDK1 protein levels in ccRCC cells. Interestingly, a sharp downregulated expression of HIF-1α was observed after hZIP1 overexpression in OSRC-2 and 786-O cells, which resulted from a downtrend of NF-kB1 moving into the cell nucleus.

Conclusion

Our work has vital implications that hZIP1 suppresses ccRCC progression by inhibiting NF-kB/HIF-1α pathway.

Comparison of Osteosarcoma Aggregated Tumour Models with Human Tissue by Multimodal Mass Spectrometry Imaging

Osteosarcoma (OS) is the most common primary bone malignancy and largely effects adolescents and young adults, with 60% of patients under the age of 25. There are multiple cell models of OS described in vitro that express the specific genetic alterations of the sarcoma. In the work reported here, multiple mass spectrometry imaging (MSI) modalities were employed to characterise two aggregated cellular models of OS models formed using the MG63 and SAOS-2 cell lines. Phenotyping of the metabolite activity within the two OS aggregoid models was achieved and a comparison of the metabolite data with OS human tissue samples revealed relevant fatty acid and phospholipid markers. Although, annotations of these species require MS/MS analysis for confident identification of the metabolites. From the putative assignments however, it was suggested that the MG63 aggregoids are an aggressive tumour model that exhibited metastatic-like potential. Alternatively, the SAOS-2 aggregoids are more mature osteoblast-like phenotype that expressed characteristics of cellular differentiation and bone development. It was determined the two OS aggregoid models shared similarities of metabolic behaviour with different regions of OS human tissues, specifically of the higher metastatic grade.

Management of oxidative stress and inflammation in cardiovascular diseases: mechanisms and challenges

Cardiovascular diseases (CVDs) have diverse physiopathological mechanisms with interconnected oxidative stress and inflammation as one of the common etiologies which result in the onset and development of atherosclerotic plaques. In this review, we illustrate this strong crosstalk between oxidative stress, inflammation, and CVD. Also, mitochondrial functions underlying this crosstalk, and various approaches for the prevention of redox/inflammatory biological impacts will be illustrated. In part, we focus on the laboratory biomarkers and physiological tests for the evaluation of oxidative stress status and inflammatory processes. The impact of a healthy lifestyle on CVD onset and development is displayed as well. Furthermore, the differences in oxidative stress and inflammation are related to genetic susceptibility to cardiovascular diseases and the variability in the assessment of CVDs risk between individuals; Omics technologies for measuring oxidative stress and inflammation will be explored. Finally, we display the oxidative stress-related microRNA and the functions of the redox basis of epigenetic modifications.

Dietary Phytochemicals in Zinc Homeostasis: A Strategy for Prostate Cancer Management

Studies have suggested an important role of the trace element zinc (Zn) in prostate biology and functions. Zn has been shown to exist in very high concentrations in the healthy prostate and is important for several prostatic functions. In prostate cancer (PCa), Zn levels are significantly decreased and inversely correlated with disease progression. Ideally, restoration of adequate Zn levels in premalignant/malignant prostate cells could abort prostate malignancy. However, studies have shown that Zn supplementation is not an efficient way to significantly increase Zn concentrations in PCa. Based on a limited number of investigations, the reason for the lower levels of Zn in PCa is believed to be the dysregulation of Zn transporters (especially ZIP and ZnT family of proteins), metallothioneins (for storing and releasing Zn), and their regulators (e.g., Zn finger transcription factor RREB1). Interestingly, the level of Zn in cells has been shown to be modulated by naturally occurring dietary phytochemicals. In this review, we discussed the effect of selected phytochemicals (quercetin, resveratrol, epigallocatechin-3-gallate and curcumin) on Zn functioning and proposes that Zn in combination with specific dietary phytochemicals may lead to enhanced Zn bioaccumulation in the prostate, and therefore, may inhibit PCa.

SLC39A8/Zinc Suppresses the Progression of Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most frequent and lethal subtype, which has high risk of metastasis or recurrence, accounting for 75–83% of renal cell carcinoma (RCC). Zrt‐ and Irt‐like proteins (ZIP) family members (SLC39A1-14) function to pass zinc into the cytoplasm for many critical biological processes when cellular zinc is depleted. However, the functional analysis of individual ZIP family genes in ccRCC is not clarified. This study aimed to investigate whether ZIP family genes are related to the clinicopathological features and survival of ccRCC patients, and to identify the function of key gene of ZIP family in ccRCC in vitro. Through bioinformatics analysis of tumor databases, SLC39A8 was identified as a key gene of ZIP family in ccRCC, which could be used as an effective indicator for diagnosing ccRCC and judging its prognosis. With the progression of tumor, the expression of SLC39A8 decreased progressively. The prognosis of patients with low expression of SLC39A8 is significantly worse. Furthermore, we found that overexpression of SLC39A8 or treatment with low concentration of zinc chloride could effectively inhibit the proliferation, migration and invasion of ccRCC cells. Moreover, the inhibition effect of SLC39A8 overexpression could be enhanced by low concentration zinc supplement. Therefore, this study provides a novel understanding for the role of SLC39A8/zinc in the regulation of ccRCC progression. These findings provide a new direction and target for progressive ccRCC drug development and combination therapy strategies.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

Varicocoele and oxidative stress: New perspectives from animal and human studies

BACKGROUND

Varicocoele (VCL), one of the main causes of male subfertility, negatively affects testicular function. Due to limited access to human testicular tissue, animal model studies have been used to evaluate molecular and, recently, epigenetic changes attributed to pathophysiology induced by VCL.

OBJECTIVES

This review aims to provide an update on the latest findings regarding the link between VCL-induced biochemical stress and molecular changes in germ cells and spermatozoa. Endocrine and antioxidant status, testicular chaperone-specific hemostasis failure, altered testicular ion balance, metabolic disorders, and altered carbon cycling during spermatogenesis are among the many features that will be presented.

DISCUSSION

Literature review coupled with our own findings suggests that ionic imbalance, hypoxia, hyperthermia, and altered blood flow could lead to severe chronic oxidative and nitrosative stress in patients with VCL leading to defective spermatogenesis and impairment of the integrity of all sperm cell components and compartments down to the epigenetic information they carry.

CONCLUSION

Since oxidative stress is an important feature of the reproductive pathology of VCL, therapeutic strategies such as the administration of appropriate antioxidants could be undertaken as a complementary non-invasive treatment line.

HIF-1α-Mediated Mitophagy Determines ZnO Nanoparticle-Induced Human Osteosarcoma Cell Death both In Vitro and In Vivo

Although ZnO nanoparticles (NPs) can kill human osteosarcoma cells, the underlying upstream regulatory mechanisms remain unclear. Since hypoxia inducible factor-1α (HIF-1α) regulates the tumor microenvironment, here we explored the interplay between HIF-1α regulation and mitophagy in ZnO NP-induced osteosarcoma inhibition both in vivo and in vitro. We found that ZnO NPs upregulated HIF-1α protein levels when they killed four common human osteosarcoma cell lines. This finding was consistent with our observations that additional HIF-1α upregulation by a hypoxia inducer CoCl₂ or under a 1% hypoxia environment enhanced NP-induced cell death, but concurrent HIF-1α suppression by a hypoxia inhibitor YC-1 or HIF-1α siRNA inhibited NP-induced cell death. We discovered an interplay between HIF-1α and the autophagy-Zn²⁺-reactive oxygen species (ROS)-autophagy cycle axis and revealed that NP-induced cancer cell killing followed a HIF-1α-BNIP3-LC3B-mediated mitophagy pathway. We confirmed that NP-upregulated HIF-1α protein expression was attributed to prolyl hydroxylase inhibition by both ROS and Zn²⁺. In addition, the in vivo assay confirmed the therapeutic effectiveness and safety of ZnO NPs on a nude mice osteosarcoma model. Collectively, our findings clarified the upstream regulatory mechanism of autophagy induced by the NPs and further demonstrated their antitumor ability in vivo. This work provides new targets and strategies for enhancing NP-based osteosarcoma treatment.

Bioenergetic signature as a target of zinc oxide nanoparticles in Ehrlich ascitic carcinoma-bearing mice

The current study aims to evaluate the modulatory effect of zinc oxide nanoparticles (ZnO NPs) on the bioenergetic signature biomarkers in the Ehrlich ascitic carcinoma (EAC) model. To achieve this goal, 90 female albino mice were included in this study and were divided into six equal groups (n   =15 per group): saline-treated group, ZnO NP-treated, EACs-bearing mice, and three groups of EACs-bearing mice treated with ZnO NPs at a dose of 20 mg/kg every other day, 10 mg/kg every other day, 10 mg/kg every day, respectively, for 14 days. The tissues from treated groups and control groups were homogenized and used for the assay of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and F1 beta subunit of adenosine triphosphate (ATP) synthase levels, as well as the determination of lactate level. The survival time of mice was improved in all ZnO NP-treated groups, especially in EACs-bearing mice treated with ZnO NPs at a dose of 10  mg/kg every other day. This improvement was associated with an increased F1 beta subunit of ATP synthase level and a decreased GAPDH level. Also, the lactate level was significantly decreased in all treated groups when compared with the untreated group. The overall effect was the increased bioenergetic signature as compared with EC.These results implied that ZnO NPs have a significant efficacy against cancer cells and they significantly increased the bioenergetic signature.

Nanotechnology for angiogenesis: opportunities and challenges

Angiogenesis plays a critical role within the human body, from the early stages of life (i.e., embryonic development) to life-threatening diseases (e.g., cancer, heart attack, stroke, wound healing). Many pharmaceutical companies have expended huge efforts on both stimulation and inhibition of angiogenesis. During the last decade, the nanotechnology revolution has made a great impact in medicine, and regulatory approvals are starting to be achieved for nanomedicines to treat a wide range of diseases. Angiogenesis therapies involve the inhibition of angiogenesis in oncology and ophthalmology, and stimulation of angiogenesis in wound healing and tissue engineering. This review aims to summarize nanotechnology-based strategies that have been explored in the broad area of angiogenesis. Lipid-based, carbon-based and polymeric nanoparticles, and a wide range of inorganic and metallic nanoparticles are covered in detail. Theranostic and imaging approaches can be facilitated by nanoparticles. Many preparations have been reported to have a bimodal effect where they stimulate angiogenesis at low dose and inhibit it at higher doses.

Role of Zinc Supplementation on Ischemia/Reperfusion Injury in Various Organs

Ischemia-reperfusion (I/R) injury is a serious condition which is associated with myocardial infarction, stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease, and sleep apnea and can lead to high morbidity and mortality. Salts of zinc (Zn) are commonly used by humans and have protective effects against gastric, renal, hepatic, muscle, myocardial, or neuronal ischemic injury. The present review evaluates molecular mechanisms underlying the protective effects of Zn supplement against I/R injury. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, and Scientific Information Database from 1991 to 2019. Zn supplementation increased the decreased parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), metallothionein (MT), protein sulfhydryl (P-SH), and nuclear factor-erythroid 2-related factor-2 (Nrf2) expression and decreased the increased elements such as endoplasmic reticulum (ER) stress, mitochondrial permeability transition pore (mPTP) opening, malondialdehyde (MDA), serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and microRNAs-(122 and 34a), apoptotic factors, and histopathological changes. Zn also increases phosphatidylinositol 3-kinase (PI3K)/Akt and glycogen synthase kinase-3β (GSK-3β) phosphorylation and preserves protein kinase C isoforms. It is suggested that Zn can be administered before elective surgeries for prevention of side effects of I/R injury.

FB-15 inhibits MGC-803 cells growth by regulating energy metabolism

In this study, we scrutinized the anticancer effects of FB-15 on human gastric carcinoma MGC-803 cells in vitro and vivo, and its preliminary effect on tubulin and HIF-1α. We confirmed that FB-15 not only inhibited the proliferation of a large number of cells in a concentration and time-dependent manner but also inhibited proliferation of a single cell to form clones. FB-15 manifested little cytotoxicity for normal stomach cells GES-1. The flow cytometry analysis displayed that FB-15 induced apoptosis MGC-803 cells and mainly arrested cells in the S phase in a concentration-dependent manner. The results of the wound healing assay indicated that FB-15 suppressed cell migration. Furthermore, the western blotting showed that FB-15 down-regulated the expression of β3-tubulin and HIF-1α, consistent with Immunohistochemical assay. The binding modes of FB-15 with tubulin were clarified by molecular docking. FB-15 significantly suppressed the growth of MGC-803 gastric cancer tumors. The inhibitory effect of FB-15 on tumor growth was superior to 5-Fu. Taken together, these results provided evidence for FB-15 to be used as an effective anticancer drug candidate for gastric cancer.

Copper and zinc levels in plasma and cancerous tissues and their relation with expression of VEGF and HIF-1 in the pathogenesis of muscle invasive urothelial bladder cancer: a case-controlled clinical study

To evaluate Cu and Zn levels in bladder cancer (BC) patients and their relationship with expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 (HIF-1). Plasma levels of Cu and Zn were determined in 66 transitional bladder cell carcinoma patients (BC group) and 60 matched controls. The concentration of Cu and Zn as well as the expressions of both VEGF and HIF-1 were also estimated in cancerous and non-cancerous bladder tissues in the BC group. The results showed that plasma Cu and Cu/Zn ratio were significantly higher in BC group when compared with the control group. In contrast, the plasma Zn in BC group was significantly lower than in the controls. Comparing levels of Cu and Zn in cancerous and non-cancerous bladder tissues among the BC group indicated a significantly higher Cu levels in the cancerous tissues, while Zn levels was significantly lower. There were higher expressions of both VEGF and HIF-1 in the cancerous samples. Moreover, the Cu concentration in cancerous tissues was significantly correlated with expressions of VEGF and HIF-1. Logistic regression analysis revealed that the increase in plasma Cu/Zn ratio and plasma Cu and the decrease in plasma Zn may be risk factors for development of bladder cancer. We concluded that alteration of plasma and bladder tissue levels of both Cu and Zn is correlated with pathogenesis of bladder cancer. The increase in Cu level in cancerous tissues of BC group has an important role in angiogenesis in bladder cancer cells.

Growth Modulatory Role of Zinc in Prostate Cancer and Application to Cancer Therapeutics

Zinc is a group IIB heavy metal. It is an important regulator of major cell signaling pathways in most mammalian cells, functions as an antioxidant and plays a role in maintaining genomic stability. Zinc deficiency leads to severe diseases in the brain, pancreas, liver, kidneys and reproductive organs. Zinc loss occurs during tumor development in a variety of cancers. The prostate normally contains abundant intracellular zinc and zinc loss is a hallmark of the development of prostate cancer development. The underlying mechanism of this loss is not clearly understood. The knowledge that excess zinc prevents the growth of prostate cancers suggests that zinc-mediated therapeutics could be an effective approach for cancer prevention and treatment, although challenges remain. This review summarizes the specific roles of zinc in several cancer types focusing on prostate cancer. The relationship between prostate cancer and the dysregulation of zinc homeostasis is examined in detail in an effort to understand the role of zinc in prostate cancer.

Advances of Zinc Signaling Studies in Prostate Cancer

Prostate cancer (PCa) is one of the most common cancers and the second leading cause of cancer-related death among men worldwide. Despite progresses in early diagnosis and therapeutic strategies, prognosis for patients with advanced PCa remains poor. Noteworthily, a unique feature of healthy prostate is its highest level of zinc content among all soft tissues in the human body, which dramatically decreases during prostate tumorigenesis. To date, several reviews have suggested antitumor activities of zinc and its potential as a therapeutic strategy of PCa. However, an overview about the role of zinc and its signaling in PCa is needed. Here, we review literature related to the content, biological function, compounds and clinical application of zinc in PCa. We first summarize zinc content in prostate tissue and sera of PCa patients with their clinical relevance. We then elaborate biological functions of zinc signaling in PCa on three main aspects, including cell proliferation, death and tumor metastasis. Finally, we discuss clinical applications of zinc-containing compounds and proteins involved in PCa signaling pathways. Based on currently available studies, we conclude that zinc plays a tumor suppressive role and can serve as a biomarker in PCa diagnosis and therapies.

Zinc dysregulation in cancers and its potential as a therapeutic target

Zinc is an essential element and serves as a structural or catalytic component in many proteins. Two families of transporters are involved in maintaining cellular zinc homeostasis: the ZIP (SLC39A) family that facilitates zinc influx into the cytoplasm, and the ZnT (SLC30A) family that facilitates zinc efflux from the cytoplasm. Zinc dyshomeostasis caused by the dysfunction of zinc transporters can contribute to the initiation or progression of various cancers, including prostate cancer, breast cancer, and pancreatic cancer. In addition, intracellular zinc fluctuations lead to the disturbance of certain signaling pathways involved in the malignant properties of cancer cells. This review briefly summarizes our current understanding of zinc dyshomeostasis in cancer, and discusses the potential roles of zinc or zinc transporters in cancer therapy.

Elemental Zn and its Binding Protein Zinc-α2-Glycoprotein are Elevated in HPV-Positive Oropharyngeal Squamous Cell Carcinoma

Human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) is biologically distinct from HPV-negative HNSCC. Outside of HPV-status, few tumor-intrinsic variables have been identified that correlate to improved survival. As part of exploratory analysis into the trace elemental composition of oropharyngeal squamous cell carcinoma (OPSCC), we performed elemental quanitification by X-ray fluorescence microscopy (XFM) on a small cohort (n = 32) of patients with HPV-positive and -negative OPSCC and identified in HPV-positive cases increased zinc (Zn) concentrations in tumor tissue relative to normal tissue. Subsequent immunohistochemistry of six Zn-binding proteins—zinc-α2-glycoprotein (AZGP1), Lipocalin-1, Albumin, S100A7, S100A8 and S100A9—revealed that only AZGP1 expression significantly correlated to HPV-status (p < 0.001) and was also increased in tumor relative to normal tissue from HPV-positive OPSCC tumor samples. AZGP1 protein expression in our cohort significantly correlated to a prolonged recurrence-free survival (p = 0.029), similar to HNSCC cases from the TCGA (n = 499), where highest AZGP1 mRNA levels correlated to improved overall survival (p = 0.023). By showing for the first time that HPV-positive OPSCC patients have increased intratumoral Zn levels and AZGP1 expression, we identify possible positive prognostic biomarkers in HNSCC as well as possible mechanisms of increased sensitivity to chemoradiation in HPV-positive OPSCC.

Plasma metals and cardiovascular disease in patients with type 2 diabetes

BACKGROUND

Metals exposure from natural environment and pollution have been linked to cardiovascular disease (CVD). However, whether associations existing between plasma multiple metals and incident cardiovascular disease in patients with type 2 diabetes (T2D) is unknown.

OBJECTIVES

We conducted a prospective cohort study to investigate whether plasma levels of metals are associated with incident CVD risk in patients with T2D.

METHODS

In a prospective study of 3897 type 2 diabetes embedded in the Dongfeng-Tongji cohort, fasting blood samples were collected in 2008 at baseline and in 2013 in the first follow-up period. Plasma concentrations of 23 metals were measured by inductively coupled plasma mass spectrometry (ICP-MS). The associations between plasma metal concentrations and CVD risk in patients with T2D were investigated with Cox proportional hazards models.

RESULTS

During an average of 6.2 years follow-up, 1114 participants developed CVD. In the single-metal models adjusting for established cardiovascular risk factors, plasma zinc and selenium levels were negatively and strontium was positively associated with incident CVD risk in patients with T2D. Similar results were obtained in the multiple-metal model, the HRs (95% CIs) for zinc, selenium, and strontium comparing extreme quartiles were 0.78 (95% CI: 0.65-0.93; P trend = 0.011), 0.76 (95% CI: 0.64-0.91; P trend = 0.001), and 1.51 (95% CI: 1.26-1.81; P trend <0.001), respectively. In the joint association analyses of two metals, individuals with high plasma levels of zinc and selenium had significantly lower risk of incident CVD in patients with T2D than those with low levels (HR = 0.77, 95% CI: 0.65-0.91).

CONCLUSIONS

The present study suggested that plasma levels of zinc and selenium had an inverse association with incident CVD risk in patients with T2D, while strontium had a positive correlation. Plasma zinc and selenium combinedly decreased incident CVD risk in patients with T2D. Further research is still needed to verify these findings in other populations.

Zinc deficiency promotes endothelin secretion and endothelial cell migration through nuclear hypoxia-inducible factor-1 translocation

Zinc is involved in the expression and function of various transcription factors, including the hypoxia-inducible factor-1 (HIF-1). HIF-1 and its target gene endothelin-1 (ET-1) are activated by intermittent hypoxia (IH), one of the main consequences of obstructive sleep apnea (OSA), and both play a key role in the cardiovascular consequences of IH. Because OSA and IH are associated with zinc deficiency, we investigated the effect of zinc deficiency caused by chelation on the HIF-1/ET-1 pathway and its functional consequences in endothelial cells. Primary human microvascular endothelial cells (HMVEC) were incubated with submicromolar doses of the zinc-specific membrane-permeable chelator N,N,N',N'-tetrakis(2-pyridylmethyl)-ethylene diamine (TPEN, 0.5 µM) or ET-1 (0.01 µM) with or without bosentan, a dual ET-1-receptor antagonist. HIF-1α expression was silenced by transfection with specific siRNA. Nuclear HIF-1 content was assessed by immunofluorescence microscopy and Western blot. Migratory capacity of HMVEC was evaluated with a wound-healing scratch assay. Zinc chelation by TPEN exposure induced the translocation of the cytosolic HIF-1α subunit of HIF-1 to the nucleus as well as an HIF-1-mediated ET-1 secretion by HMVEC. Incubation with either TPEN or ET-1 increased endothelial wound-healing capacity. Both HIF-1α silencing or bosentan abolished this effect. Altogether, these results suggest that zinc deficiency upregulates ET-1 signaling through HIF-1 activation and stimulates endothelial cell migration, suggesting an important role of zinc in the vascular consequences of IH and OSA mediated by HIF-1-ET- signaling.

Selective Inhibition of HIF1α Expression by ZnSO4 Has Antitumoral Effects in Human Melanoma

Zinc as an essential trace metal is a ubiquitous component of various molecules of the cell. Studies indicated that it may modulate functions of various cancer cell types, and can even inhibit metastasis formation in experimental models. In melanoma, zinc was shown to affect melanin production and to induce apoptosis. Using human melanoma cell lines, we have tested the effects of ZnSO₄ on cell proliferation, survival, migration as well as in vivo on experimental liver colony formation. We have found that ZnSO₄ has antiproliferative and proapoptotic effects in vitro. In SCID mice intraperitoneal administration of ZnSO₄ specifically inhibited liver colony formation without affecting primary tumor growth. To reveal the molecular mechanisms of action of zinc in human melanoma, we have tested mRNA expression of zinc finger transcription factors and found a strong inhibitory effect on HIF1α, as compared to WT1 whereas HIF2α and MTF1 expression was unaffected. Immunohistochemical detection of HIF1α protein in liver metastases confirmed its decreased nuclear expression after in vivo ZnSO₄ treatment. These data indicate that in human melanoma zinc administration may have an antimetastatic effect due to a selective downregulation of HIF1α.

Elevated Na/H exchanger 1 (SLC9A1) emerges as a marker for tumorigenesis and prognosis in gliomas

Background

Sodium/hydrogen exchanger 1 (NHE1), encoded by the SLC9A1 gene (SoLute Carrier family 9A1) in humans, is the main H⁺ efflux mechanism in maintaining alkaline intracellular pH (pH_i) and Warburg effects in glioma. However, to date, there are no clinical studies exploring pharmacological inhibition of NHE1 protein in cancer treatment. In this study, we investigated NHE1 expression in gliomas and its relationship with glioma clinical outcome.

Methods

The Chinese Glioma Genome Atlas (CGGA) dataset containing transcriptome sequencing data of 325 glioma samples and the Cancer Genome Atlas (TCGA) with 698 glioma mRNAseq data were analyzed in this study. Mouse SB28 and GL26 intracranial syngeneic glioma models in C57BL/6 J mice were established to investigate NHE1 expression and impact of NHE1 protein inhibition with its inhibitor HOE642 on tumorigenesis and anti-PD1 therapy. Tumor angiogenesis, immunogenicity, and progression were assessed by immunofluorescence staining and flow cytometric profiling.

Results

Analysis of SLC9A1 mRNA expression in two data sets, CGGA and TCGA, reveals significantly higher SLC9A1 mRNA levels in higher grade gliomas. The SLC9A1 mRNA expression was especially enriched in isocitrate dehydrogenase (IDH)1/2 wild-type glioblastoma (GBM) and in mesenchymal glioma subtypes. Worsened survival probabilities were correlated with the elevated SLC9A1 mRNA levels in gliomas. The underlying mechanisms include promoting angiogenesis, and extracellular matrix remodeling. Increased SLC9A1 mRNA expression was also associated with tumor-associated macrophage accumulation. NHE1 inhibitor HOE642 reduced glioma volume, invasion, and prolonged overall survival in mouse glioma models. Blockade of NHE1 protein also stimulated immunogenic tumor microenvironment via activating CD8 T-cell accumulation, increasing expression of interferon-gamma (Ifng), and sensitized animals to anti-PD-1 therapy.

Conclusion

Our findings strongly suggest that NHE1 protein emerges as a marker for tumorigenesis and prognosis in glioma. Blocking NHE1 protein is a novel strategy for adjuvant anti-cancer therapies.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0923-z) contains supplementary material, which is available to authorized users.

Glioblastoma Chemoresistance: The Double Play by Microenvironment and Blood-Brain Barrier

For glioblastoma, the tumor microenvironment (TME) is pivotal to support tumor progression and therapeutic resistance. TME consists of several types of stromal, endothelial and immune cells, which are recruited by cancer stem cells (CSCs) to influence CSC phenotype and behavior. TME also promotes the establishment of specific conditions such as hypoxia and acidosis, which play a critical role in glioblastoma chemoresistance, interfering with angiogenesis, apoptosis, DNA repair, oxidative stress, immune escape, expression and activity of multi-drug resistance (MDR)-related genes. Finally, the blood brain barrier (BBB), which insulates the brain microenvironment from the blood, is strongly linked to the drug-resistant phenotype of glioblastoma, being a major physical and physiological hurdle for the delivery of chemotherapy agents into the brain. Here, we review the features of the glioblastoma microenvironment, focusing on their involvement in the phenomenon of chemoresistance; we also summarize recent advances in generating systems to modulate or bypass the BBB for drug delivery into the brain. Genetic aspects associated with glioblastoma chemoresistance and current immune-based strategies, such as checkpoint inhibitor therapy, are described too.

Zinc deficiency and cellular oxidative stress: prognostic implications in cardiovascular diseases

Zinc is an essential nutrient for human health and has anti-oxidative stress and anti-inflammatory functions. The association between zinc deficiency and the development of cardiovascular diseases (CVDs) has been supported by numerous studies. Supplementing zinc can reduce the risk of atherosclerosis and protect against myocardial infarction and ischemia/reperfusion injury. In this review we summarize the evidence in the literature, to consolidate the current knowledge on the dysregulation of zinc homeostasis in CVDs, and to explore the significant roles of the zinc homeostasis-regulatory proteins in cardiac physiology and pathophysiology. Moreover, this review also deliberates on the potential diagnostic and prognostic implications of zinc/zinc homeostasis-associated molecules (ZIP, ZnT, and MTs) in CVDs.