The iron metabolism of neoplastic cells: alterations that facilitate proliferation?

Docosahexaenoic acid-loaded nanoparticles: A state-of-the-art of preparation methods, characterization, functionality, and therapeutic applications

Docosahexaenoic acid (DHA, C22:6 n-3), an omega-3 polyunsaturated fatty acid, offers several beneficial effects. DHA helps in reducing depression, autoimmune diseases, rheumatoid arthritis, attention deficit hyperactivity syndrome, and cardiovascular diseases. It can stimulate the development of brain and nerve, alleviate lipids metabolism-related disorders, and enhance vision development. However, DHA susceptibility to chemical oxidation, poor water solubility, and unpleasant order could restrict its applications for nutritional and therapeutic purposes. To avoid these drawbacks and enhance its bioavailability, DHA can be encapsulated using an effective delivery system. Several encapsulation methods are recognized, and DHA-loaded nanoparticles have demonstrated numerous benefits. In clinical studies, positive influences on the development of several diseases have been reported, but some assumptions are conflicting and need more exploration, since DHA has a systemic and not a targeted release at the required level. This might cause the applications of nanoparticles that could allow DHA release at the required level and improve its efficiency, thus resulting in a better controlling of several diseases. In the current review, we focused on researches investigating the formulation and development of DHA-loaded nanoparticles using different delivery systems, including low-density lipoprotein, zinc oxide, silver, zein, and resveratrol-stearate. Silver-DHA nanoparticles presented a typical particle size of 24 nm with an incorporation level of 97.67 %, while the entrapment efficiency of zinc oxide-DHA nanoparticles represented 87.3 %. By using zein/Poly (lactic-co-glycolic acid) stabilized nanoparticles, DHA's encapsulation level reached 84.6 %. We have also highlighted the characteristics, functionality and medical implementation of these nanoparticles in the treatment of inflammations, brain disorders, diabetes as well as hepatocellular carcinoma.

Pathophysiological aspects of transferrin-A potential nano-based drug delivery signaling molecule in therapeutic target for varied diseases

Transferrin (Tf), widely known for its role as an iron-binding protein, exemplifies multitasking in biological processes. The role of Tf in iron metabolism involves both the uptake of iron from Tf by various cells, as well as the endocytosis mediated by the complex of Tf and the transferrin receptor (TfR). The direct conjugation of the therapeutic compound and immunotoxin studies using Tf peptide or anti-Tf receptor antibodies as targeting moieties aims to prolong drug circulation time and augment efficient cellular drug uptake, diminish systemic toxicity, traverse the blood-brain barrier, restrict systemic exposure, overcome multidrug resistance, and enhance therapeutic efficacy with disease specificity. This review primarily discusses the various biological actions of Tf, as well as the development of Tf-targeted nano-based drug delivery systems. The goal is to establish the use of Tf as a disease-targeting component, accentuating the potential therapeutic applications of this protein.

Differential transmetallation of complexes of the anti-cancer thiosemicarbazone, Dp4e4mT: effects on anti-proliferative efficacy, redox activity, oxy-myoglobin and oxy-hemoglobin oxidation

The di-2-pyridylthiosemicarbazone (DpT) analogs demonstrate potent and selective anti-proliferative activity against human tumors. The current investigation reports the synthesis and chemical and biological characterization of the Fe(iii), Co(iii), Ni(ii), Cu(ii), Zn(ii), Ga(iii), and Pd(ii) complexes of the promising second generation DpT analog, di-2-pyridylketone-4-ethyl-4-methyl-3-thiosemicarbazone (Dp4e4mT). These studies demonstrate that the Dp4e4mT Co(iii), Ni(ii), and Pd(ii) complexes display distinct biological activity versus those with Cu(ii), Zn(ii), and Ga(iii) regarding anti-proliferative efficacy against cancer cells and a detrimental off-target effect involving oxidation of oxy-myoglobin (oxy-Mb) and oxy-hemoglobin (oxy-Hb). With regards to anti-proliferative activity, the Zn(ii) and Ga(iii) Dp4e4mT complexes demonstrate facile transmetallation with Cu(ii), resulting in efficacy against tumor cells that is strikingly similar to the Dp4e4mT Cu(ii) complex (IC50: 0.003-0.006 μM and 72 h). Relative to the Zn(ii) and Ga(iii) Dp4e4mT complexes, the Dp4e4mT Ni(ii) complex demonstrates kinetically slow transmetallation with Cu(ii) and intermediate anti-proliferative effects (IC50: 0.018-0.076 μM after 72 h). In contrast, the Co(iii) and Pd(ii) complexes demonstrate poor anti-proliferative activity (IC50: 0.262-1.570 μM after 72 h), probably due to a lack of transmetallation with Cu(ii). The poor efficacy of the Dp4e4mT Co(iii), Ni(ii), and Pd(ii) complexes to transmetallate with Fe(iii) markedly suppresses the oxidation of oxy-Mb and oxy-Hb. In contrast, the 2 : 1 Dp4e4mT: Cu(ii), Zn(ii), and Ga(iii) complexes demonstrate facile reactions with Fe(iii), leading to the redox active Dp4e4mT Fe(iii) complex and oxy-Mb and oxy-Hb oxidation. This study demonstrates the key role of differential transmetallation of Dp4e4mT complexes that has therapeutic ramifications for their use as anti-cancer agents.

Deeper insight into ferroptosis: association with Alzheimer's, Parkinson's disease, and brain tumors and their possible treatment by nanomaterials induced ferroptosis

Ferroptosis is an emerging and novel type of iron-dependent programmed cell death which is mainly caused by the excessive deposition of free intracellular iron in the brain cells. This deposited free iron exerts a ferroptosis pathway, resulting in lipid peroxidation (LiPr). There are mainly three ferroptosis pathways viz. iron metabolism-mediated cysteine/glutamate, and LiPr-mediated. Iron is required by the brain as a redox metal for several physiological activities. Due to the iron homeostasis balance disruption, the brain gets adversely affected which further causes neurodegenerative diseases (NDDs) like Parkinson's and Alzheimer's disease, strokes, and brain tumors like glioblastoma (GBS), and glioma. Nanotechnology has played an important role in the prevention and treatment of these NDDs. A synergistic effect of nanomaterials and ferroptosis could prove to be an effective and efficient approach in the field of nanomedicine. In the current review, the authors have highlighted all the latest research in the field of ferroptosis, specifically emphasizing on the role of major molecular key players and various mechanisms involved in the ferroptosis pathway. Moreover, here the authors have also addressed the correlation of ferroptosis with the pathophysiology of NDDs and theragnostic effect of ferroptosis and nanomaterials for the prevention and treatment of NDDs.

Steric Blockade of Oxy-Myoglobin Oxidation by Thiosemicarbazones: Structure-Activity Relationships of the Novel PPP4pT Series

The di-2-pyridylketone thiosemicarbazones demonstrated marked anticancer efficacy, prompting progression of DpC to clinical trials. However, DpC induced deleterious oxy-myoglobin oxidation, stifling development. To address this, novel substituted phenyl thiosemicarbazone (PPP4pT) analogues and their Fe(III), Cu(II), and Zn(II) complexes were prepared. The PPP4pT analogues demonstrated potent antiproliferative activity (IC50: 0.009-0.066 μM), with the 1:1 Cu:L complexes showing the greatest efficacy. Substitutions leading to decreased redox potential of the PPP4pT:Cu(II) complexes were associated with higher antiproliferative activity, while increasing potential correlated with increased redox activity. Surprisingly, there was no correlation between redox activity and antiproliferative efficacy. The PPP4pT:Fe(III) complexes attenuated oxy-myoglobin oxidation significantly more than the clinically trialed thiosemicarbazones, Triapine, COTI-2, and DpC, or earlier thiosemicarbazone series. Incorporation of phenyl- and styryl-substituents led to steric blockade, preventing approach of the PPP4pT:Fe(III) complexes to the heme plane and its oxidation. The 1:1 Cu(II):PPP4pT complexes were inert to transmetalation and did not induce oxy-myoglobin oxidation.

Lipocalin-2: A Nurturer of Tumor Progression and a Novel Candidate for Targeted Cancer Therapy

Within the tumor microenvironment (TME) exists a complex signaling network between cancer cells and stromal cells, which determines the fate of tumor progression. Hence, interfering with this signaling network forms the basis for cancer therapy. Yet, many types of cancer, in particular, solid tumors, are refractory to the currently used treatments, so there is an urgent need for novel molecular targets that could improve current anti-cancer therapeutic strategies. Lipocalin-2 (Lcn-2), a secreted siderophore-binding glycoprotein that regulates iron homeostasis, is highly upregulated in various cancer types. Due to its pleiotropic role in the crosstalk between cancer cells and stromal cells, favoring tumor progression, it could be considered as a novel biomarker for prognostic and therapeutic purposes. However, the exact signaling route by which Lcn-2 promotes tumorigenesis remains unknown, and Lcn-2-targeting moieties are largely uninvestigated. This review will (i) provide an overview on the role of Lcn-2 in orchestrating the TME at the level of iron homeostasis, macrophage polarization, extracellular matrix remodeling, and cell migration and survival, and (ii) discuss the potential of Lcn-2 as a promising novel drug target that should be pursued in future translational research.

An updated review on distribution, biosynthesis and pharmacological effects of artemisinin: A wonder drug

Plant-based drugs have been used for centuries for treating different ailments. Malaria, one of the prevalent threats in many parts of the world, is treated mainly by artemisinin-based drugs derived from plants of genus Artemisia. However, the distribution of artemisinin is restricted to a few species of the genus; besides, its yield depends on ontogeny and the plant's geographical location. Here, we review the studies focusing on biosynthesis and distributional pattern of artemisinin production in species of the genus Artemisia. We also discussed various agronomic and in vitro methods and molecular approaches to increase the yield of artemisinin. We have summarized different mechanisms of artemisinin involved in its anti-malarial, anti-cancer, anti-inflammatory and anti-viral activities (like against Covid-19). Overall the current review provides a synopsis of a global view of the distribution of artemisinin, its biosynthesis, and pharmacological potential in treating various diseases like malaria, cancer, and coronavirus, which may provoke future research efforts in drug development. Nevertheless, long-term trials and molecular approaches, like CRISPR-Cas, are required for in-depth research.

The Myc Family and the Metastasis Suppressor NDRG1: Targeting Key Molecular Interactions with Innovative Therapeutics

Cancer is a leading cause of death worldwide, resulting in ∼10 million deaths in 2020. Major oncogenic effectors are the Myc proto-oncogene family, which consists of three members including c-Myc, N-Myc, and L-Myc. As a pertinent example of the role of the Myc family in tumorigenesis, amplification of MYCN in childhood neuroblastoma strongly correlates with poor patient prognosis. Complexes between Myc oncoproteins and their partners such as hypoxia-inducible factor-1α and Myc-associated protein X (MAX) result in proliferation arrest and pro-proliferative effects, respectively. Interactions with other proteins are also important for N-Myc activity. For instance, the enhancer of zest homolog 2 (EZH2) binds directly to N-Myc to stabilize it by acting as a competitor against the ubiquitin ligase, SCFFBXW7, which prevents proteasomal degradation. Heat shock protein 90 may also be involved in N-Myc stabilization since it binds to EZH2 and prevents its degradation. N-Myc downstream-regulated gene 1 (NDRG1) is downregulated by N-Myc and participates in the regulation of cellular proliferation via associating with other proteins, such as glycogen synthase kinase-3β and low-density lipoprotein receptor-related protein 6. These molecular interactions provide a better understanding of the biologic roles of N-Myc and NDRG1, which can be potentially used as therapeutic targets. In addition to directly targeting these proteins, disrupting their key interactions may also be a promising strategy for anti-cancer drug development. This review examines the interactions between the Myc proteins and other molecules, with a special focus on the relationship between N-Myc and NDRG1 and possible therapeutic interventions. SIGNIFICANCE STATEMENT: Neuroblastoma is one of the most common childhood solid tumors, with a dismal five-year survival rate. This problem makes it imperative to discover new and more effective therapeutics. The molecular interactions between major oncogenic drivers of the Myc family and other key proteins; for example, the metastasis suppressor, NDRG1, may potentially be used as targets for anti-neuroblastoma drug development. In addition to directly targeting these proteins, disrupting their key molecular interactions may also be promising for drug discovery.

The Antimalarial Drug Artesunate Mediates Selective Cytotoxicity by Upregulating HO-1 in Melanoma Cells

Despite great efforts to develop new therapeutic strategies to combat melanoma, the prognosis remains rather poor. Artesunate (ART) is an antimalarial drug displaying anti-cancer effects in vitro and in vivo. In this in vitro study, we investigated the selectivity of ART on melanoma cells. Furthermore, we aimed to further elucidate the mechanism of the drug with a focus on the role of iron, the induction of oxidative stress and the implication of the enzyme heme oxygenase 1 (HO-1). ART treatment decreased the cell viability of A375 melanoma cells while it did not affect the viability of normal human dermal fibroblasts, used as a model for normal (healthy) cells. ART's toxicity was shown to be dependent on intracellular iron and the drug induced high levels of oxidative stress as well as upregulation of HO-1. Melanoma cells deficient in HO-1 or treated with a HO-1 inhibitor were less sensitive towards ART. Taken together, our study demonstrates that ART induces oxidative stress resulting in the upregulation of HO-1 in melanoma cells, which subsequently triggers the effect of ART's own toxicity. This new finding that HO-1 is involved in ART-mediated toxicity may open up new perspectives in cancer therapy.

Magnetospirillum magneticum triggers apoptotic pathways in human breast cancer cells

The use of bacteria in cancer immunotherapy has the potential to bypass many shortcomings of conventional treatments. The ability of anaerobic bacteria to preferentially accumulate and replicate in hypoxic regions of solid tumors, as a consequence of bacterial metabolic needs, is particularly advantageous and key to boosting their immunostimulatory therapeutic actions in situ. While several of these bacterial traits are well-studied, little is known about their competition for nutrients and its effect on cancer cells which could serve as another potent and innate antineoplastic action. Here, we explored the consequences of the iron-scavenging abilities of a particular species of bacteria, Magnetospirillum magneticum, which has been studied as a potential new class of bacteria for magnetically targeted bacterial cancer therapy. We investigated their influence in hypoxic regions of solid tumors by studying the consequential metabolic effects exerted on cancer cells. To do so, we established an in vitro co-culture system consisting of the bacterial strain AMB-1 incubated under hypoxic conditions with human breast cancer cells MDA-MB-231. We first quantified the number of viable cells after incubation with magnetotactic bacteria demonstrating a lower rate of cellular proliferation that correlated with increasing bacteria-to-cancer cells ratio. Further experiments showed increasing populations of apoptotic cells when cancer cells were incubated with AMB-1 over a period of 24 h. Analysis of the metabolic effects induced by bacteria suggest an increase in the activation of executioner caspases as well as changes in levels of apoptosis-related proteins. Finally, the level of several human apoptosis-related proteins was investigated, confirming a bacteria-dependent triggering of apoptotic pathways in breast cancer cells. Overall, our findings support that magnetotactic bacteria could act as self-replicating iron-chelating agents and indicate that they interfere with proliferation and lead to increased apoptosis of cancer cells. This bacterial feature could serve as an additional antineoplastic mechanism to reinforce current bacterial cancer therapies.

Amounts of tissue magnesium and some trace elements in cats with mammary tumors related to various clinicopathological parameters

BACKGROUND

Mammary tumors are one of the major malignancies seen in cats. Researchers have indicated the similarity between the epidemiological and clinicopathological patterns of feline mammary tumors and human breast cancer (HBC). In recent years, the investigation of trace elements in cancer tissues becomes prevalent in HBC due to the role of these elements in biochemical and physiological processes. This study, it is aimed to evaluate some trace elements in feline mammary tumors according to clinical and pathological findings.

METHODS

A total of 60 tumoral masses from 16 female cats with mammary tumors were included in the study. The study groups were formed according to histopathology as malignant epithelial tumor (MET; n = 39) and hyperplasia and dysplasia (H&D; n = 21). Copper (Cu), Iron (Fe), Magnesium (Mg), Manganese (Mn), Selenium (Se) and Zinc (Zn) trace elements in mammary tissues were analyzed by using an inductively coupled plasma-optical emission spectrophotometer.

RESULTS

The mean age and weight of the cats were 11.75 ± 0.75 years and 3.35 ± 0.21 kg; respectively. Eleven of 16 cats were intact whereas the rest of them had been spayed. Metastases were observed in 10 cats. Tissue Mg level in group MET was significantly higher than in group H&D (P < 0.01) while the other elements had not significant differences between the groups. In group MET, analyzed elements were not statistically significant related to the inflammation, ulceration and invasion to the peripheral muscle (P > 0.05). However, tissue Fe level was significantly higher in T2 than in T3 (P < 0.05). The mean levels of tissue Fe, Mg and Mn had significant differences related to histological grading as P < 0.01, P < 0.05 and P < 0.001; respectively. A mild to severe correlation was found between tissue Zn and Se, Cu, Fe, Mg, and Mn levels.

CONCLUSION

Tissue Mg and some trace elements were evaluated in feline mammary tumours in regard to various clinicopathological parameters. Tissue Mg level was sufficient to differentiate the malignant epithelial tumors from hyperplasia and dysplasia. However, Mn and Se tended to distinguish different tumor types. Tissue Fe, Mg and Mn had significant differences related to histological grading. Also, the Fe level was significantly higher in T2 than in T3 and Zn level tended to be higher in T3 than in T1. It was concluded that Mg, Se, Mn, Fe, Cu and Zn provided useful information on the pathogenesis of feline mammary tumors. Further research is needed on the tissue and serum concentrations of trace elements which may provide valuable information for the disease prognosis.

The role of the NDRG1 in the pathogenesis and treatment of breast cancer

Breast cancer (BC) is the leading cause of cancer death in women. This disease is heterogeneous, with clinical subtypes being estrogen receptor-α (ER-α) positive, having human epidermal growth factor receptor 2 (HER2) overexpression, or being triple-negative for ER-α, progesterone receptor, and HER2 (TNBC). The ER-α positive and HER2 overexpressing tumors can be treated with agents targeting these proteins, including tamoxifen and pertuzumab, respectively. Despite these treatments, resistance and metastasis are problematic, while TNBC is challenging to treat due to the lack of suitable targets. Many studies examining BC and other tumors indicate a role for N-myc downstream-regulated gene-1 (NDRG1) as a metastasis suppressor. The ability of NDRG1 to inhibit metastasis is due, in part, to the inhibition of the initial step in metastasis, namely the epithelial-to-mesenchymal transition. Paradoxically, there are also reports of NDRG1 playing a pro-oncogenic role in BC pathogenesis. The oncogenic effects of NDRG1 in BC have been reported to relate to lipid metabolism or the mTOR signaling pathway. The molecular mechanism(s) of how NDRG1 regulates the activity of multiple signaling pathways remains unclear. Therapeutic strategies that up-regulate NDRG1 have been developed and include agents of the di-2-pyridylketone thiosemicarbazone class. These compounds target oncogenic drivers in BC cells, suppressing the expression of multiple key hormone receptors including ER-α, progesterone receptor, androgen receptor, and prolactin receptor, and can also overcome tamoxifen resistance. Considering the varying role of NDRG1 in BC pathogenesis, further studies are required to examine what subset of BC patients would benefit from pharmacopeia that up-regulate NDRG1.

Designing Tailored Thiosemicarbazones with Bespoke Properties: The Styrene Moiety Imparts Potent Activity, Inhibits Heme Center Oxidation, and Results in a Novel "Stealth Zinc(II) Complex"

A novel, potent, and selective antitumor agent, namely (E)-3-phenyl-1-(2-pyridinyl)-2-propen-1-one 4,4-dimethyl-3-thiosemicarbazone (PPP44mT), and its analogues were synthesized and characterized and displayed strikingly distinctive properties. This activity was mediated by the inclusion of a styrene moiety, which through steric and electrochemical mechanisms prevented deleterious oxy-myoglobin or oxy-hemoglobin oxidation relative to other potent thiosemicarbazones, i.e., di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) or di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT). Structure-activity relationship analysis demonstrated specific tuning of PPP44mT electrochemistry further inhibited oxy-myoglobin or oxy-hemoglobin oxidation. Both PPP44mT and its Cu(II) complexes showed conspicuous almost immediate cytotoxicity against SK-N-MC tumor cells (within 3 h). In contrast, [Zn(PPP44mT)₂] demonstrated a pronounced delay in activity, taking 48 h before marked antiproliferative efficacy was apparent. As such, [Zn(PPP44mT)₂] was designated as a "stealth Zn(II) complex" that overcomes the near immediate cytotoxicity of PPP44mT or its copper complexes. Upon examination of the suppression of oncogenic signaling, [Zn(PPP44mT)₂] was superior at inhibiting cyclin D1 expression compared to DpC or Dp44mT.

KLF14 regulates the growth of hepatocellular carcinoma cells via its modulation of iron homeostasis through the repression of iron-responsive element-binding protein 2

BACKGROUND

Hepatocellular carcinoma (HCC) is a multifactor-driven malignant tumor with rapid progression, which causes the difficulty to substantially improve the prognosis of HCC. Limited understanding of the mechanisms in HCC impedes the development of efficacious therapies. Despite Krüpple-Like factors (KLFs) were reported to be participated in HCC pathogenesis, the function of KLF14 in HCC remains largely unexplored.

METHODS

We generated KLF14 overexpressed and silenced liver cancer cells, and nude mouse xenograft models for the in vitro and in vivo study. Luciferase reporter assay, ChIP-qPCR, Co-IP, immunofluorescence were performed for mechanism research. The expression of KLF14 in HCC samples was analyzed by quantitative RT-PCR, Western blotting, and immunohistochemistry (IHC) analysis.

RESULTS

KLF14 was significantly downregulated in human HCC tissues, which was highly correlated with poor prognosis. Inhibition of KLF14 promoted liver cancer cells proliferation and overexpression of KLF14 suppressed cells growth. KLF14 exerts its anti-tumor function by inhibiting Iron-responsive element-binding protein 2 (IRP2), which then causes transferrin receptor-1(TfR1) downregulation and ferritin upregulation on the basis of IRP-IREs system. This then leading to cellular iron deficiency and HCC cells growth suppression in vitro and in vivo. Interestingly, KLF14 suppressed the transcription of IRP2 via recruiting SIRT1 to reduce the histone acetylation of the IRP2 promoter, resulting in iron depletion and cell growth suppression. More important, we found fluphenazine is an activator of KLF14, inhibiting HCC cells growth through inducing iron deficiency.

CONCLUSION

KLF14 acts as a tumor suppressor which inhibits the proliferation of HCC cells by modulating cellular iron metabolism via the repression of IRP2. We identified Fluphenazine, as an activator of KLF14, could be a potential compound for HCC therapy. Our findings therefore provide an innovative insight into the pathogenesis of HCC and a promising therapeutic target.

Implication of Ferroptosis in Cholangiocarcinoma: A Potential Future Target?

Cholangiocarcinoma (CCA), the second most common liver neoplasm, has a poor overall 5-year survival rate of less than 10%. A deeper understanding of the molecular pathogenesis contributing to CCA progression is essential for developing better therapeutic approaches to manage this disease. Ferroptosis, an oxidative iron-dependent form of regulated cell death, has been reported to be involved in tumorigenesis and progression. In particular, ferroptosis and inflammation, which are common issues in cholangiocarcinogenesis and CCA development, might be in concert with disease progression. Notably, the key feature of cancer cells is "iron addiction", which is crucial for the high metabolic demand in carcinogenesis and cancer progression. Additionally, iron metabolism is of great importance in ferroptosis. Moreover, that cancer cells are vulnerable to ferroptosis might be a possible mechanism of CCA development. Although the underlying mechanism of how ferroptosis is implicated in CCA development requires further investigation, developing a new strategy combined with a pro-ferroptotic treatment would be an exciting CCA treatment approach in the future.

GLUT1 Immunohistochemistry Is a Highly Sensitive and Relatively Specific Marker for Erythroid Lineage in Benign and Malignant Hematopoietic Tissues

OBJECTIVES

Glucose transporter 1 (GLUT1), a glucose transporter, is an abundant protein in erythrocytes with expression beginning early in erythropoiesis. We sought to evaluate the utility of GLUT1 immunohistochemistry (IHC) as a diagnostic marker for identifying erythroid differentiation in hematopoietic tissues, including neoplastic erythroid proliferations.

METHODS

A variety of benign and neoplastic bone marrow biopsy specimens containing variable proportions of erythroid precursors were selected (n = 46, including 36 cases of leukemia). GLUT1 IHC was performed using a commercially available polyclonal antibody. Each case was evaluated for staining of erythroid precursors, nonerythroid hematopoietic cells, and blasts. A GATA1/GLUT1 double stain was performed on one case to confirm coexpression of GLUT1 on early erythroid precursors. Staining was compared with other erythroid markers, including glycophorin C.

RESULTS

GLUT1 demonstrated strong membranous staining in erythroid precursors of all cases, which was restricted largely to the erythroid lineage. Of the 36 leukemia cases, all 6 cases of pure erythroid leukemia and both cases of therapy-related acute myeloid leukemia with erythroid differentiation showed positive GLUT1 staining in blasts. Otherwise, only lymphoblasts in B-lymphoblastic leukemia showed weak to moderate granular cytoplasmic staining (four of five cases).

CONCLUSIONS

GLUT1 IHC is a highly sensitive and relatively specific marker for erythroid lineage in benign and neoplastic bone marrow biopsy specimens.

Probing Transferrin Receptor Overexpression in Gastric Cancer Mice Models

Exposure to carcinogenic chemicals, Helicobacter pylori infection, and high dietary salt are the risk factors associated with gastric cancer. Mice models of gastric cancer are key to understanding the cancer mechanism, to discerning the role played by different factors, and to determining therapeutic effects of different treatments. The goal has been to find targets which are only expressed with cancer so that they can be targeted specifically without harming normal cells. One such target could be the transferrin receptor, a glycoprotein receptor that is expressed many-folds on rapidly growing cells due to the greater demand of iron. In this study, gastric cancer was developed in mice (BALB/c) with human cancer-associated risk factors by feeding them with tumor-inducing concentration of methyl nitrosourea, dietary salt, and H. pylori along with normal feed and water. Three strategies were adopted to induce gastric cancer; (1) use of N-methyl-N-nitrosourea (MNU) with high dietary salt (NaCl), (2) infection with H. pylori (isolated from human gastric tissue), and (3) use of MNU along with high concentration of NaCl after H. pylori infection. Mice were dissected after induction, and histological study of gastric tissue was done with Hematoxylin and Eosin staining. A diagnostic probe comprising transferrin conjugated with cadmium sulfide quantum dots was prepared and characterized. It was used to study the transferrin receptor overexpression in gastric tissue of cancer-induced mice relative to the normal mice. Mice of group 3 showed the highest rate of the cancer incidence ratio (96%) along with a high expression of transferrin receptors among the three groups. Histochemical studies showed that different types of gastric cancer depend upon the cancer-induction conditions. The mouse model of group 3 has the potential to be used in the future to study the therapeutic effects of cancer medicines, and overexpression of transferrin receptors could be identified through the designed probe to be used as diagnostics.

Mitoxantrone-Loaded Nanoferritin Slows Tumor Growth and Improves the Overall Survival Rate in a Subcutaneous Pancreatic Cancer Mouse Model

Pancreatic cancer (PC) represents an intriguing topic for researchers. To date, the prognosis of metastasized PC is poor with just 7% of patients exceeding a five-year survival period. Thus, molecular modifications of existing drugs should be developed to change the course of the disease. Our previously generated nanocages of Mitoxantrone (MIT) encapsulated in human H-chain Ferritin (HFt), designated as HFt-MP-PASE-MIT, has shown excellent tumor distribution and extended serum half-life meriting further investigation for PC treatment. Thus, in this study, we used the same nano-formulation to test its cytotoxicity using both in vitro and in vivo assays. Interestingly, both encapsulated and free-MIT drugs demonstrated similar killing capabilities on PaCa44 cell line. Conversely, in vivo assessment in a subcutaneous PaCa44 tumor model of PC demonstrated a remarkable capability for encapsulated MIT to control tumor growth and improve mouse survival with a median survival rate of 65 vs. 33 days for loaded and free-MIT, respectively. Interestingly, throughout the course of mice treatment, MIT encapsulation did not present any adverse side effects as confirmed by histological analysis of various murine tissue organs and body mass weights. Our results are promising and pave the way to effective PC targeted chemotherapy using our HFt nanodelivery platforms.

A novel formulation of theranostic nanomedicine for targeting drug delivery to gastrointestinal tract cancer

Background

Theranostic nanomedicines contain a nanovehicle that has fluorescent properties and can be used for diagnostic, therapeutic and prognostic purposes. The transferrin receptor expression is 1000-fold higher in rapidly growing cancer cells as compared to the normal cells and, therefore, can be used in targeted drug delivery systems. The objective of the present study was to design a novel targeted gold nanoparticle (GNPs)-based theranostic formulation for gastrointestinal (GI) tract-related cancers. The synthesized GNPs were conjugated to transferrin and doxorubicin both separately and collectively to check their cytotoxic properties. The in vitro cytotoxicity of nanocomposites was observed against colon cancer cell line HCT-116. The doxorubicin conjugated nanocomposites showed almost the same cytotoxicity, but more effect at later hours (h). The IC50 and IC100 were 50 µg/ml and 250 µg/ml, respectively, equivalent to the doxorubicin weight for GNP theranostic nanomedicine.

Results

The maximum effect was observed after 12 h and nanomedicines were still active after 72 h of treatment. Our in vivo data proved that nanomedicine crossed all the barriers and was successfully delivered to the tumour cells. Theranostic nanomedicine’s (TNM) effect on body weight and survival rate on mice was many folds better than mice in pure doxorubicin group. It also showed almost 80% survival rate on day 40. The in vivo and in vitro results show the effects of prolonged drug release and the nanomedicine was not toxic to vital organs of the animal.

Conclusion

This is one of its kind studies in which a novel targeted nanomedicines approach was formulated for therapeutic as well as prognostic purposes against GI tract cancer.

Graphic Abstract

The Real Cytotoxic Effect of Artemisinins on Colon Cancer Cells in a Physiological Cell Culture Setting. How Composition of the Culture Medium Biases Experimental Findings

Artemisinin (ART) and dihydroartemisinin (DHA) are anti-malaria drugs but also exhibit huge anticancer potential based on ferroptosis driven by iron-dependent lipid peroxidation. This study was conducted on primary (SW480), metastatic (SW620) colon cancer, and noncancerous HaCaT cells at pharmacologically relevant drug concentrations (1-8 µM) and in the presence of holotransferrin (TRFi 50 µM) and linoleic acid (LA 20, 40 µM) at physiological levels. ART and DHA showed the growth inhibitory potency which was significantly increased in the presence of LA or/and TRFi. The IC₅₀ for ART or DHA, LA40 and TRFi combination in both cancer cell lines ranged 0.14-0.69 µM whereas no cytotoxic effect was observed for HaCaT cells (SI = 202-480). Almost all experimental settings revealed late apoptosis in both cancer cell lines, but not in normal cells. The percentage of late apoptotic cells increased with LA concentrations and was intensified after TRFi addition. The strongest pro-apoptic effect was exhibited by ART or DHA, LA40, and TRFi combination. More interestingly, we found a stimulatory effect of TRFi on IL-6 synthesis. The present study using LA and TRFi which are inherent blood components revealed high antitumor artemisinin activity in concentrations achievable after drug administration to cancer patients without toxic effects on normal cells.

Innovative therapies for neuroblastoma: The surprisingly potent role of iron chelation in up-regulating metastasis and tumor suppressors and down-regulating the key oncogene, N-myc

Iron is an indispensable requirement for essential biological processes in cancer cells. Due to the greater proliferation of neoplastic cells, their demand for iron is considerably higher relative to normal cells, making them highly susceptible to iron depletion. Understanding this sensitive relationship led to research exploring the effect of iron chelation therapy for cancer treatment. The classical iron-binding ligand, desferrioxamine (DFO), has demonstrated effective anti-proliferative activity against many cancer-types, particularly neuroblastoma tumors, and has the surprising activity of down-regulating the potent oncogene, N-myc, which is a major oncogenic driver in neuroblastoma. Even more significant is the ability of DFO to simultaneously up-regulate the potent metastasis suppressor, N-myc downstream-regulated gene-1 (NDRG1), which plays a plethora of roles in suppressing a variety of oncogenic signaling pathways. However, DFO suffers the disadvantage of demonstrating poor membrane permeability and short plasma half-life, requiring administration by prolonged subcutaneous or intravenous infusions. Considering this, the specifically designed di-2-pyridylketone thiosemicarbazone (DpT) series of metal-binding ligands was developed in our laboratory. The lead agent from the first generation DpT series, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), showed exceptional anti-cancer properties compared to DFO. However, it exhibited cardiotoxicity in mouse models at higher dosages. Therefore, a second generation of agents was developed with the lead compound being di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) that progressed to Phase I clinical trials. Importantly, DpC showed better anti-proliferative activity than Dp44mT and no cardiotoxicity, demonstrating effective anti-cancer activity against neuroblastoma tumors in vivo.

Can the iron content of culture media impact on the leishmanicidal effect of artemisinin?

Endoperoxides (EPs) like artemisinin following cleavage of their EP bridge can kill parasites via generation of carbon-centered radicals. As the presence of low molecular mass iron and/or heme is crucial, this study aimed to establish the influence of iron on the leishmanicidal action of artemisinin when present in differing amounts in culture media. In promastigotes cultured in Schneiders insect medium (SIM), that had a 8.0-fold higher amount of iron as compared to Medium 199 (M199), the impact of artemisinin on cell viability, redox status, labile iron pool (LIP), and Annexin-V positivity was evaluated. In SIM, the IC50 of artemisinin was 25.50-fold lower than M199, and in both media its cytotoxicity was decreased by the addition of hemin or following chelation of Fe2+ by Deferoxamine (DFO). In SIM vis-a-vis M199, artemisinin caused a greater redox imbalance which translated into a higher degree of externalization of phosphatidylserine and depletion of the LIP. The presence of a higher proportion of iron in SIM as compared to M199 significantly enhanced the cytotoxicity of artemisinin in Leishmania promastigotes, and was attributed to a higher degree of iron-mediated cleavage of its EP bridge that led to a higher generation of free radicals.

Parkinson's disease: Alterations in iron and redox biology as a key to unlock therapeutic strategies

A plethora of studies indicate that iron metabolism is dysregulated in Parkinson's disease (PD). The literature reveals well-documented alterations consistent with established dogma, but also intriguing paradoxical observations requiring mechanistic dissection. An important fact is the iron loading in dopaminergic neurons of the substantia nigra pars compacta (SNpc), which are the cells primarily affected in PD. Assessment of these changes reveal increased expression of proteins critical for iron uptake, namely transferrin receptor 1 and the divalent metal transporter 1 (DMT1), and decreased expression of the iron exporter, ferroportin-1 (FPN1). Consistent with this is the activation of iron regulator protein (IRP) RNA-binding activity, which is an important regulator of iron homeostasis, with its activation indicating cytosolic iron deficiency. In fact, IRPs bind to iron-responsive elements (IREs) in the 3ꞌ untranslated region (UTR) of certain mRNAs to stabilize their half-life, while binding to the 5ꞌ UTR prevents translation. Iron loading of dopaminergic neurons in PD may occur through these mechanisms, leading to increased neuronal iron and iron-mediated reactive oxygen species (ROS) generation. The "gold standard" histological marker of PD, Lewy bodies, are mainly composed of α-synuclein, the expression of which is markedly increased in PD. Of note, an atypical IRE exists in the α-synuclein 5ꞌ UTR that may explain its up-regulation by increased iron. This dysregulation could be impacted by the unique autonomous pacemaking of dopaminergic neurons of the SNpc that engages L-type Ca+2 channels, which imparts a bioenergetic energy deficit and mitochondrial redox stress. This dysfunction could then drive alterations in iron trafficking that attempt to rescue energy deficits such as the increased iron uptake to provide iron for key electron transport proteins. Considering the increased iron-loading in PD brains, therapies utilizing limited iron chelation have shown success. Greater therapeutic advancements should be possible once the exact molecular pathways of iron processing are dissected.

Role of iron in cancer

Iron is an essential metal for cellular metabolism. The reduced form of iron is a cofactor in numerous redox reactions in the cell and is therefore required for many vital physiological functions. Since iron is an oxidatively active metal, its homeostasis is tightly regulated in healthy cell. Most of iron exists in a protein-bound form, in erythrocytes as the heme compound hemoglobin, and in storage proteins such as ferritin, hemosiderin and myoglobin. Iron also is bound to proteins and non-heme enzymes involved in oxidation-reduction reactions and the transfer of electrons. There is no free iron inside the cell, however a small fraction of loosely bound iron is found in the cytoplasm. This poorly defined pool of ferrous iron is called labile iron pool. Under pathological conditions iron homeostasis may be disrupted at different levels including absorption, systemic transportation, and cellular uptake and storage. Cancer cells display dysregulated iron homeostasis and, for reasons yet poorly understood, require more iron for their metabolism and growth. As a result, in cancer cells labile iron pool is increased, and loosely bound iron catalyzes Fenton reaction and perhaps other reactions that generate reactive oxygen species. Oxygen-derived free radicals produce DNA mutations, damage proteins and lipids resulting in either cell death or cell transformation.

Deferasirox induces cyclin D1 degradation and apoptosis in mantle cell lymphoma in a reactive oxygen species- and GSK3β-dependent mechanism

Mantle cell lymphoma (MCL) is a difficult-to-treat B-cell malignancy characterized by cyclin D1 (CD1) overexpression. Targeting CD1 in MCL has been shown to be of therapeutic significance. However, treatment of MCL remains challenging since patients are still subject to early and frequent relapse of the disease. To ensure their high proliferation rate, tumour cells have increased iron needs, making them more susceptible to iron deprivation. Indeed, several iron chelators proved to be effective anti-cancer agents. In this study, we demonstrate that the clinically approved iron chelator deferasirox (DFX) exerts an anti-tumoural effect in MCL cell lines and patient cells. The exposure of MCL cells to clinically feasible concentrations of DFX resulted in growth inhibition, cell cycle arrest and induction of apoptosis. We show that DFX unfolds its cytotoxic effect by a rapid induction of reactive oxygen species (ROS) that leads to oxidative stress and severe DNA damage and by triggering CD1 proteolysis in a mechanism that requires its phosphorylation on T286 by glycogen synthase kinase-3β (GSK3β). Moreover, we demonstrate that DFX mediates CD1 proteolysis by repressing the phosphatidylinositol 3-kinase (PI3K)/AKT/GSK3β pathway via ROS generation. Our data suggest DFX as a potential therapeutic option for MCL and paves the way for more treatment options for these patients.

Ferrous Iron-Dependent Pharmacology

The recent emergence of oxidation state selective probes of cellular iron has produced a more nuanced understanding of how cells utilize this crucial nutrient to empower enzyme function, and also how labile ferrous iron contributes to iron-dependent cell death (ferroptosis) and other disease pathologies including cancer, bacterial infections, and neurodegeneration. These findings, viewed in light of the Fenton chemistry promoted by ferrous iron, suggest a new category of therapeutics exhibiting ferrous iron-dependent pharmacology. While still in its infancy, this nascent field draws inspiration from the remarkable activity and tremendous clinical impact of the antimalarial artemisinin. Here, we review recent insights into the role of labile ferrous iron in biology and disease, and describe new therapeutic approaches designed to exploit this divalent transition metal.

YM155, specific survivin inhibitor, can enhance artesunate-induced cytotoxicity in HCT116 colon cancer cells

Purpose

A water-soluble variant of the artemisinin called artesunate, approved as an antimalarial agent, can induce cell death on various cancer cell types. We studied the mechanism of cell death of artesunate on HCT116 colorectal cancer cells.

Methods

We treated HCT116 colon cancer cells with artesunate, holo-transferrin, deferoxamine mesylate, ferrostatin, necrostatin-1, and YM155. We observed the growth inhibition of artesunate on HCT116 colon cancer cells by morphologic findings. Inhibition of cell growth was assessed by MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) assay and long-term growth inhibition by colony-forming assay. Apoptosis was investigated by flow cytometry and Western blot analysis.

Results

Artesunate inhibited the proliferation of HCT116 colon cancer cells effectively. Co-treatment with YM155, a specific survivin inhibitor, enhanced the artesunate-induced cell death. Co-treatment with the iron-chelating agent deferoxamine rescued artesunate induced cell death and increased long-term cell survival and proliferation.

Conclusion

In this study, we demonstrated that artesunate-induced cytotoxicity in HCT116 colon cancer cells by suppressing the expression of survivin and partially by ferroptosis. Our findings suggest that the co-treatment artesunate with YM155 can induce more potent cell death on HCT116 colon cancer cells and shows new insight for the treatment of colorectal cancer patients.

Cancer and mosquitoes - An unsuspected close connection

Cancer is a major public health issue and represents a significant burden in countries with different levels of economic wealth. In parallel, mosquito-borne infectious diseases represent a growing problem causing significant morbidity and mortality worldwide. Acknowledging that these two concerns are both globally distributed, it is essential to investigate whether they have a reciprocal connection that can fuel their respective burdens. Unfortunately, very few studies have examined the link between these two threats. This review provides an overview of the possible links between mosquitoes, mosquito-borne infectious diseases and cancer. We first focus on the impact of mosquitoes on carcinogenesis in humans including the transmission of oncogenic pathogens through mosquitoes, the immune reactions following mosquito bites, the presence of non-oncogenic mosquito-borne pathogens, and the direct transmission of cancer cells. The second part of this review deals with the direct or indirect consequences of cancer in humans on mosquito behaviour. Thirdly, we discuss the potential impacts that natural cancers in mosquitoes can have on their life history traits and therefore on their vector capacity. Finally, we discuss the most promising research avenues on this topic and the integrative public health strategies that could be envisioned in this context.

Ascorbate and Tumor Cell Iron Metabolism: The Evolving Story and Its Link to Pathology

Significance: Vitamin C or ascorbate (Asc) is a water-soluble vitamin and an antioxidant that is involved in many crucial biological functions. Asc's ability to reduce metals makes it an essential enzyme cofactor. Recent Advances: The ability of Asc to act as a reductant also plays an important part in its overall role in iron metabolism, where Asc induces both nontransferrin-bound iron and transferrin-bound iron uptake at physiological concentrations (∼50 μM). Moreover, Asc has emerged to play an important role in multiple diseases and its effects at pharmacological doses could be important for their treatment. Critical Issues: Asc's role as a regulator of cellular iron metabolism, along with its cytotoxic effects and different roles at pharmacological concentrations, makes it a candidate as an anticancer agent. Ever since the controversy regarding the studies from the Mayo Clinic was finally explained, there has been a renewed interest in using Asc as a therapeutic approach toward cancer due to its minimal side effects. Numerous studies have been able to demonstrate the anticancer activity of Asc through selective oxidative stress toward cancer cells via H₂O₂ generation at pharmacological concentrations. Studies have demonstrated that Asc's cytotoxic mechanism at concentrations (>1 mM) has been associated with decreased cellular iron uptake. Future Directions: Recent studies have also suggested other mechanisms, such as Asc's effects on autophagy, polyamine metabolism, and the cell cycle. Clearly, more has yet to be discovered about Asc's mechanism of action to facilitate safe and effective treatment options for cancer and other diseases.

Hydroxypyridinone-Based Iron Chelators with Broad-Ranging Biological Activities

Iron plays an essential role in all living cells because of its unique chemical properties. It is also the most abundant trace element in mammals. However, when iron is present in excess or inappropriately located, it becomes toxic. Excess iron can become involved in free radical formation, resulting in oxidative stress and cellular damage. Iron chelators are used to treat serious pathological disorders associated with systemic iron overload. Hydroxypyridinones stand out for their outstanding chelation properties, including high selectivity for Fe³⁺ in the biological environment, ease of derivatization, and good biocompatibility. Herein, we overview the potential for multifunctional hydroxypyridinone-based chelators to be used as therapeutic agents against a wide range of diseases associated either with systemic or local elevated iron levels.

Identification of the Active Compounds and Significant Pathways of Artemisia Annua in the Treatment of Non-Small Cell Lung Carcinoma based on Network Pharmacology

Background

Artemisia annua exerts powerful effects in non-small cell lung carcinoma (NSCLC). Some studies have shown that Artemisia annua possesses the characteristics of new therapeutic drugs for NSCLC patients. However, the underlying molecular mechanism of Artemisia annua anti-NSCLC is not yet fully elucidated because Artemisia annua contains hundreds of ingredients. This study aimed to conduct network pharmacological analysis on the mechanism of action of Artemisia annua against NSCLC.

Material/Methods

The active ingredients and corresponding potential targets of Artemisia annua were searched and screened in the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Then through The Cancer Genome Atlas (TCGA) and the National Center for Biotechnology Information (NCBI) databases to establish NSCLC related targets. Based on the matching results of Artemisia annua potential targets and NSCLC targets, a protein–protein interaction (PPI) network was constructed to analyze the interactions between these targets and topologically screen the central targets. Furthermore, Gene Ontology (GO) biological functions analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) signal pathways enrichment were carried out.

Results

There were 19 main active ingredients of Artemisia annua screened for target prediction; 40 NSCLC-related common targets were identified via multiple NSCLC databases. The node area and corresponding degree value of AKT1, MYC, CCND1, VEGFA, JUN, MAPK1, EGFR, and ESR1 were large and could be easily found in the PPI network. The aforementioned results were further verified by the analysis of GO biological function and KEGG enrichment analysis.

Conclusions

The network pharmacology analysis reveals the molecular biological mechanism of Artemisia annua anti-NSCLC via multiple active components, multi-channels, and multi-targets. This suggests that Artemisia annua might be developed as a promising anti-NSCLC drug.

Acireductone dioxygenase 1 (ADI1) is regulated by cellular iron by a mechanism involving the iron chaperone, PCBP1, with PCBP2 acting as a potential co-chaperone

The iron-containing protein, acireductone dioxygenase 1 (ADI1), is a dioxygenase important for polyamine synthesis and proliferation. Using differential proteomics, the studies herein demonstrated that ADI1 was significantly down-regulated by cellular iron depletion. This is important, since ADI1 contains a non-heme, iron-binding site critical for its activity. Examination of multiple human cell-types demonstrated a significant decrease in ADI1 mRNA and protein after incubation with iron chelators. The decrease in ADI1 after iron depletion was reversible upon incubation of cells with the iron salt, ferric ammonium citrate (FAC). A significant decrease in ADI1 mRNA levels was observed after 14 h of iron depletion. In contrast, the chelator-mediated reduction in ADI1 protein occurred earlier after 10 h of iron depletion, suggesting additional post-transcriptional regulation. The proteasome inhibitor, MG-132, prevented the iron chelator-mediated decrease in ADI1 expression, while the lysosomotropic agent, chloroquine, had no effect. These results suggest an iron-dependent, proteasome-mediated, degradation mechanism. Poly r(C)-binding protein (PCBPs) 1 and 2 act as iron delivery chaperones to other iron-containing dioxygenases and were shown herein for the first time to be regulated by iron levels. Silencing of PCBP1, but not PCBP2, led to loss of ADI1 expression. Confocal microscopy co-localization studies and proximity ligation assays both demonstrated decreased interaction of ADI1 with PCBP1 and PCBP2 under conditions of iron depletion using DFO. These data indicate PCBP1 and PCBP2 interact with ADI1, but only PCBP1 plays a role in ADI1 expression. In fact, PCBP2 appeared to play an accessory role, being involved as a potential co-chaperone.

Air pollutants disrupt iron homeostasis to impact oxidant generation, biological effects, and tissue injury

Air pollutants cause changes in iron homeostasis through: 1) a capacity of the pollutant, or a metabolite(s), to complex/chelate iron from pivotal sites in the cell or 2) an ability of the pollutant to displace iron from pivotal sites in the cell. Through either pathway of disruption in iron homeostasis, metal previously employed in essential cell processes is sequestered after air pollutant exposure. An absolute or functional cell iron deficiency results. If enough iron is lost or is otherwise not available within the cell, cell death ensues. However, prior to death, exposed cells will attempt to reverse the loss of requisite metal. This response of the cell includes increased expression of metal importers (e.g. divalent metal transporter 1). Oxidant generation after exposure to air pollutants includes superoxide production which functions in ferrireduction necessary for cell iron import. Activation of kinases and phosphatases and transcription factors and increased release of pro-inflammatory mediators also result from a cell iron deficiency, absolute or functional, after exposure to air pollutants. Finally, air pollutant exposure culminates in the development of inflammation and fibrosis which is a tissue response to the iron deficiency challenging cell survival. Following the response of increased expression of importers and ferrireduction, activation of kinases and phosphatases and transcription factors, release of pro-inflammatory mediators, and inflammation and fibrosis, cell iron is altered, and a new metal homeostasis is established. This new metal homeostasis includes increased total iron concentrations in cells with metal now at levels sufficient to meet requirements for continued function.

Variation in Blood and Colorectal Epithelia's Key Trace Elements Along with Expression of Mismatch Repair Proteins from Localized and Metastatic Colorectal Cancer Patients

Colorectal cancer (CRC) is an increasingly common medical issue affecting millions worldwide, and contribution of the body's trace elements to CRC is arguable. The concentrations and buffered status of selenium, iron, copper, zinc, and phosphorus in blood and large intestinal tissues of CRC patients are, respectively, variable and vital for cell physiology. The aim of this study was to assess selenium, iron, copper, zinc, and phosphorus variations in blood and colorectal epithelia along with examining the expression of mismatch repair proteins in CRC patients with/without metastasis for potential diagnosis/therapy. Concentrations of selenium, iron, copper, zinc, and phosphorus in blood of healthy versus CRC patients and colorectal epithelia (adenocarcinomatous versus non-adenocarcinomatous/control) were measured in 40 CRC patients (55.87 ± 11.9 years old) with/without metastasis before surgery using ICP-OES. Mismatch repair (MMR) protein expression was analyzed through histopathological/immunohistochemistry assays, which was sparse in 5 CRC patient's colorectal tissues (12%). Compared with healthy individuals, blood and colorectal tissue's levels of phosphorus, copper, and iron were significantly higher in the CRC patients, and more pronounced in metastatic CRC patients; conversely, blood and colorectal tissue's selenium levels were significantly lower in metastatic patients. Unlike blood zinc, cancerous colorectal tissue's zinc concentration was significantly lower in CRC patients compared to healthy control cohorts. There was no significant difference on the measured elements in samples from CRC patients with MMR^- compared to CRC patients with MMR⁺. Receiver operating characteristic analysis revealed a correlation of blood iron, zinc, copper, and phosphorus to CRC, and inappropriately low levels of blood and colorectal selenium correlated with exacerbated metastasis. Altered levels of selenium, iron, copper, zinc, and phosphorus in vivo may impact the pathogenesis and detection of CRC, and their diagnostic/therapeutic potential in CRC would be revealing.

A systematic review and meta-analysis on the association of serum and tumor tissue iron and risk of breast cancer

BACKGROUND

Some studies have investigated the effects of iron on breast carcinogenesis and reported different findings about the association between Fe and breast cancer risk. This study was conducted to estimate this effect using meta-analysis method.

METHODS

A total of 20 articles published between 1984 and 2017 worldwide were selected through searching PubMed, Scopus, Embase, Web of Science, and Cochrane Library. Keywords such Breast Cancer, Neoplasm, Trace elements, Iron, Breast tissue concentration, Plasma concentration, Scalp hair concentration, toenail concentration and their combination were used in the search.

RESULTS

The total number of participants was 4,110 individuals comprising 1,624 patients with breast cancer and 2,486 healthy subjects. Fe concentration was measured in the various subgroups in both case and control groups. There were significant correlations between Fe concentration and breast cancer in breast tissue subgroup (SMD: 0.67 [95% CI: 0.17 to 1.17; P=0.009]). Whereas, there was no meaningful difference in Fe status between women with and without breast cancer related to scalp hair and plasma subgroups; (SMD: -3.74 [95% CI: -7.58 to 0.10; P=0.056] and (SMD:-1.14[95% CI: -2.30 to 0.03; P=0.055], respectively.

CONCLUSION

The present meta-analysis indicated a positive and straight association between iron concentrations and risk of breast cancer but because of high heterogeneity we recommend more accurate future studies.

Lifetime Transfusion Burden and Transfusion-Related Iron Overload in Adult Survivors of Solid Malignancies

BACKGROUND

Limited data exist on transfusion burden and transfusion-related iron overload in adult survivors of solid malignancies.

METHODS

Hospital-specific cancer registry data of patients with solid tumor receiving systemic anticancer treatment between January 2008 and September 2009 at the Oncology Department of the Leiden University Medical Center (The Netherlands) were retrieved and cross-referenced with red blood cell (RBC) transfusion records. Individual lifetime transfusion burden was captured in April 2015. Multitransfused long-term survivors with serum ferritin >500 μg/L were subsequently screened for hepatic and cardiac iron overload using 1.5 Tesla magnetic resonance imaging.

RESULTS

The study population consisted of 775 adult patients with solid cancer (45.2% male; median age, 58 years; >75% chemotherapy-treated), 423 (54.6%) of whom were transfused with a median of 6.0 RBC units (range 1-67). Transfusion triggers were symptomatic anemia or hemoglobin <8.1-8.9 g/dL prior to each myelosuppressive chemotherapy cycle. We identified 123 (15.9%) patients across all tumor types with a lifetime transfusion burden of ≥10 RBC units. In the absence of a hemovigilance program, none of these multitransfused patients was screened for iron overload despite a median survival of 4.6 years. In 2015 at disclosure of transfusion burden, 26 multitransfused patients were alive. Six (23.1%) had hepatic iron overload: 3.9-11.2 mg Fe/g dry weight. No cardiac iron depositions were found.

CONCLUSION

Patients with solid malignancies are at risk for multitransfusion and iron overload even when adhering to restrictive RBC transfusion policies. With improved long-term cancer survivorship, increased awareness of iatrogenic side effects of supportive therapy and development of evidence-based guidelines are essential.

IMPLICATIONS FOR PRACTICE

In the presence of a restrictive transfusion policy, ∼30% of transfused adult patients with solid cancer are multitransfused and ∼50% become long-term survivors, underscoring the need for evidence-based guidelines for the detection and management of transfusion-related iron overload in this group of patients. In each institution, a hemovigilance program should be implemented that captures the lifetime cumulative transfusion burden in all patients with cancer, irrespective of tumor type. This instrument will allow timely assessment and treatment of iron overload in cancer survivors, thus preventing organ dysfunction and decreased quality of life.

Iron regulatory protein 2 is a suppressor of mutant p53 in tumorigenesis

p53 is known to play a role in iron homeostasis and is required for FDXR-mediated iron metabolism via iron regulatory protein 2 (IRP2). Interestingly, p53 is frequently mutated in tumors wherein iron is often accumulated, suggesting that mutant p53 may exert its gain of function by altering iron metabolism. In this study, we found that FDXR deficiency decreased mutant p53 expression along with altered iron metabolism in p53^R270H/- MEFs and cancer cells carrying mutant p53. Consistently, we found that decreased expression of mutant p53 by FDXR deficiency inhibited mutant p53-R270H to induce carcinoma and high grade pleomorphic sarcoma in FDXR^+/-; p53^R270H/- mice as compared with p53^R270H/- mice. Moreover, we found that like its effect on wild-type p53, loss of IRP2 increased mutant p53 expression. However, unlike its effect to suppress cell growth in cells carrying wild-type p53, loss of IRP2 promoted cell growth in cancer cells expressing mutant p53. Finally, we found that ectopic expression of IRP2 suppressed cell growth in a mutant p53-dependent manner. Together, our data indicate that mutant p53 gain-of-function can be suppressed by IRP2 and FDXR deficiency, both of which may be explored to target tumors carrying mutant p53.

Iron Compounds as Anticancer Agents

Many ferrocene complexes have been prepared for their oncological potential. Some derive from molecules with known biological effects (taxanes, podophyllotoxine, artemisine, SAHA, etc.) while others are synthetic molecules selected for their cytotoxic effects (N-alkylaminoferrocenes and ferrocenyl alkylpyridinium). Although these complexes have received a great deal of attention, the field of iron metallodrugs is not limited to them. A number of inorganic complexes of iron(ii) and iron(iii) with possible anticancer effects have also been published, although research into their biological effects is often only at an early stage. This chapter also includes iron chelators, molecules that are administered in non-metallic form but whose cytotoxic species are their coordination complexes of iron generated in vivo. The most emblematic molecule of this family is bleomycin, used as an anticancer agent in many chemotherapies. To these can be added the iron chelates originally synthesized to treat iron overload, some of which have been shown to possess interesting anticancer properties. They have been, and continue to be, the subject of many clinical trials, whether alone or in combination. Thus, the area of iron metallodrugs includes molecules with very different structures and reactivity, studied from a number of different perspectives, but focused on increasing the number of molecules at our disposal for combatting cancer.

Reverse Chemical Proteomics Identifies an Unanticipated Human Target of the Antimalarial Artesunate

Artemisinins are the most potent and safe antimalarials available. Despite their clinical potential, no human target for the artemisinins is known. The unbiased interrogation of several human cDNA libraries, displayed on bacteriophage T7, revealed a single human target of artesunate; the intrinsically disordered Bcl-2 antagonist of cell death promoter (BAD). We show that artesunate inhibits the phosphorylation of BAD, thereby promoting the formation of the proapoptotic BAD/Bcl-xL complex and the subsequent intrinsic apoptotic cascade involving cytochrome c release, PARP cleavage, caspase activation, and ultimately cell death. This unanticipated role of BAD as a possible drug target of artesunate points to direct clinical exploitation of artemisinins in the Bcl-xL life/death switch and that artesunate's anticancer activity is, at least in part, independent of reactive oxygen species.

Ironing out the role of the cyclin-dependent kinase inhibitor, p21 in cancer: Novel iron chelating agents to target p21 expression and activity

Iron (Fe) has become an important target for the development of anti-cancer therapeutics with a number of Fe chelators entering human clinical trials for advanced and resistant cancer. An important aspect of the activity of these compounds is their multiple molecular targets, including those that play roles in arresting the cell cycle, such as the cyclin-dependent kinase inhibitor, p21. At present, the exact mechanism by which Fe chelators regulate p21 expression remains unclear. However, recent studies indicate the ability of chelators to up-regulate p21 at the mRNA level was dependent on the chelator and cell-type investigated. Analysis of the p21 promoter identified that the Sp1-3-binding site played a significant role in the activation of p21 transcription by Fe chelators. Furthermore, there was increased Sp1/ER-α and Sp1/c-Jun complex formation in melanoma cells, suggesting these complexes were involved in p21 promoter activation. Elucidating the mechanisms involved in the regulation of p21 expression in response to Fe chelator treatment in neoplastic cells will further clarify how these agents achieve their anti-tumor activity. It will also enhance our understanding of the complex roles p21 may play in neoplastic cells and lead to the development of more effective and specific anti-cancer therapies.

Iron as a Central Player and Promising Target in Cancer Progression

Iron is an essential element for virtually all organisms. On the one hand, it facilitates cell proliferation and growth. On the other hand, iron may be detrimental due to its redox abilities, thereby contributing to free radical formation, which in turn may provoke oxidative stress and DNA damage. Iron also plays a crucial role in tumor progression and metastasis due to its major function in tumor cell survival and reprogramming of the tumor microenvironment. Therefore, pathways of iron acquisition, export, and storage are often perturbed in cancers, suggesting that targeting iron metabolic pathways might represent opportunities towards innovative approaches in cancer treatment. Recent evidence points to a crucial role of tumor-associated macrophages (TAMs) as a source of iron within the tumor microenvironment, implying that specifically targeting the TAM iron pool might add to the efficacy of tumor therapy. Here, we provide a brief summary of tumor cell iron metabolism and updated molecular mechanisms that regulate cellular and systemic iron homeostasis with regard to the development of cancer. Since iron adds to shaping major hallmarks of cancer, we emphasize innovative therapeutic strategies to address the iron pool of tumor cells or cells of the tumor microenvironment for the treatment of cancer.

Dried leaf Artemisia annua efficacy against non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is a major subtype of lung cancer with poor prognosis. Artemisinin (AN), produced naturally in Artemisia annua L., has anti-cancer activity. Artemisinin delivered as dried leaf Artemisia (DLA) showed efficacy against malaria in rodents and humans.

HYPOTHESIS/PURPOSE

DLA is posited as being at least as efficacious as artesunate (AS) in its ability to induce cytotoxicity in NSCLC cells and also inhibit tumor growth in a NSCLC xenograft murine model.

STUDY DESIGN

Three NSCLC cell lines were used, a non-cancerous human fibroblast line, and xenograft murine models to compare efficacy of artemisinin delivered p.o. via DLA, DLA extracts (DLAe), and AS.

METHODS

DLAe was compared to AS using NSCLC cell lines A549, H1299 and PC9 as well as non-cancerous human dermal fibroblasts (HDF) CCD-1108Sk line. Cell viability, cell migration and cell cycle were compared for AS and DLAe. Westerns measured activated caspases-3, -8 and -9 to determine involvement of intrinsic and/or extrinsic apoptotic pathways. Xenograft murine models of A549 and PC9 cells were used to measure tumor growth inhibition by AS or DLA, with tumor volume the primary endpoint.

RESULTS

Both DLAe and AS suppressed A549, H1299 and PC9 cell viability with no inhibition of non-cancerous HDF CCD-1108Sk cells. Caspases-3, -8 and -9 were activated, suggesting cell death was stimulated through both intrinsic and/or extrinsic apoptotic pathways. Both drugs induced G2/M or mitotic arrest in PC9 and H1299 cells, and DLAe induced G1 arrest in A549 cells. AS and DLAe induced DNA damage as double stranded breaks evidenced by phosphorylation of histone H2AX. DLAe inhibited migration of PC9 and A549 cells. In A549 xenografted animals, p.o. AS and DLA inhibited relative tumor growth by 40% and 50%, respectively, compared to controls. AS was ineffective at inhibiting PC9-induced tumor growth, but DLA inhibited relative tumor growth by ∼50% compared to controls.

CONCLUSION

This is the first study demonstrating efficacy of DLA and mechanistic differences of DLAe vs. AS, against NSCLC cells. Compared to AS, DLA possesses qualities of a novel therapeutic for patients with NSCLC.

Iron Metabolism in Cancer

Demanded as an essential trace element that supports cell growth and basic functions, iron can be harmful and cancerogenic though. By exchanging between its different oxidized forms, iron overload induces free radical formation, lipid peroxidation, DNA, and protein damages, leading to carcinogenesis or ferroptosis. Iron also plays profound roles in modulating tumor microenvironment and metastasis, maintaining genomic stability and controlling epigenetics. in order to meet the high requirement of iron, neoplastic cells have remodeled iron metabolism pathways, including acquisition, storage, and efflux, which makes manipulating iron homeostasis a considerable approach for cancer therapy. Several iron chelators and iron oxide nanoparticles (IONPs) has recently been developed for cancer intervention and presented considerable effects. This review summarizes some latest findings about iron metabolism function and regulation mechanism in cancer and the application of iron chelators and IONPs in cancer diagnosis and therapy.

The iron chelator deferasirox synergises with chemotherapy to treat triple-negative breast cancers

To ensure their high proliferation rate, tumor cells have an iron metabolic disorder causing them to have increased iron needs, making them more susceptible to iron deprivation. This vulnerability could be a therapeutic target. In breast cancers, the development of new therapeutic approaches is urgently needed for patients with triple-negative tumors, which frequently relapse after chemotherapy and suffer from a lack of targeted therapies. In this study, we demonstrated that deferasirox (DFX) synergises with standard chemotherapeutic agents such as doxorubicin, cisplatin and carboplatin to inhibit cell proliferation and induce apoptosis and autophagy in triple-negative breast cancer (TNBC) cells. Moreover, the combination of DFX with doxorubicin and cyclophosphamide delayed recurrences in breast cancer patient-derived xenografts without increasing the side-effects of chemotherapies alone or altering the global iron storage of mice. Antitumor synergy of DFX and doxorubicin seems to involve downregulation of the phosphoinositide 3-kinase and nuclear factor-κB pathways. Iron deprivation in combination with chemotherapy could thus help to improve the effectiveness of chemotherapy in TNBC patients without increasing toxicity. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Expression of iron-related proteins in feline and canine mammary gland reveals unexpected accumulation of iron

Dysregulation of cellular iron homeostasis in human breast cancer is reflected by the altered expression of regulatory proteins. The expressions of iron-related proteins in the mammary glands of cats and dogs have not been assessed. We evaluated the expressions of ferritin, ferroportin, hepcidin and transferrin receptor 1 in benign and malignant mammary gland lesions in cats and dogs. Iron deposition was detected using Perls' Prussian blue staining. We found no major differences in the expression of iron-related proteins between benign and malignant mammary gland lesions in either cats or dogs; however, these species exhibited accumulation of iron in benign lesions. Our findings provide an explanation for the absence of higher iron requirements by tumor cells in these animals. Further investigation of local iron homeostasis in cats and dogs and differences in their physiology compared to human breast cancer is required.

Low-density lipoprotein docosahexaenoic acid nanoparticles induce ferroptotic cell death in hepatocellular carcinoma

Low-density lipoprotein nanoparticles reconstituted with the natural omega-3 fatty acid, docosahexaenoic acid (LDL-DHA), have been reported to selectively kill hepatoma cells and reduce the growth of orthotopic liver tumors in the rat. To date, little is known about the cell death pathways by which LDL-DHA nanoparticles kill tumor cells. Here we show that the LDL-DHA nanoparticles are cytotoxic to both rat hepatoma and human hepatocellular carcinoma (HCC) cell lines. Following LDL-DHA treatment both rat and human HCC cells experience pronounced lipid peroxidation, depletion of glutathione and inactivation of the lipid antioxidant glutathione peroxidase-4 (GPX4) prior to cell death. Inhibitor studies revealed that the treated HCC cells die independent of apoptotic, necroptotic or autophagic pathways, but require the presence of cellular iron. These hallmark features are consistent and were later confirmed to reflect ferroptosis, a novel form of nonapoptotic iron-dependent cell death. In keeping with the mechanisms of ferroptosis cell death, GPX4 was also found to be a central regulator of LDL-DHA induced tumor cell killing. We also investigated the effects of LDL-DHA treatments in mice bearing human HCC tumor xenografts. Intratumoral injections of LDL-DHA severely inhibited the growth of HCC xenografts long term. Consistent with our in vitro findings, the LDL-DHA treated HCC tumors experienced ferroptotic cell death characterized by increased levels of tissue lipid hydroperoxides and suppression of GPX4 expression.

CONCLUSION

LDL-DHA induces cell death in HCC cells through the ferroptosis pathway, this represents a novel molecular mechanism of anticancer activity for LDL-DHA nanoparticles.