Iron promotes breast cancer cell migration via IL-6/JAK2/STAT3 signaling pathways in a paracrine or autocrine IL-6-rich inflammatory environment

Antiapoptotic and Prometastatic Roles of Cytokine FAM3B in Triple-Negative Breast Cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. FAM3B, a secreted protein, has been extensively studied in various types of tumors. However, its function in breast cancer remains poorly understood.

METHODS

We analyzed FAM3B expression data from breast cancer patients available at TCGA database and overall survival was analyzed by using the Kaplan-Meier plotter. MDA-MB-231 TNBC tumor cell line and hormone-responsive MCF-7 cell lines were transfected to overexpress FAM3B. We assessed cell death, tumorigenicity, and invasiveness in vitro through MTT analysis, flow cytometry assays, anchorage-independent tumor growth, and wound healing assays, respectively. We performed in vivo evaluation by tumor xenograft in nude mice.

RESULTS

In silico analysis revealed that FAM3B expression was lower in all breast tumors. However, TNBC patients with high FAM3B expression had a poor prognosis. FAM3B overexpression protected MDA-MB-231 cells from cell death, with increased expression of Bcl-2 and Bcl-xL, and reduced caspase-3 activity. MDA-MB-231 cells overexpressing FAM3B also exhibited increased tumorigenicity and migration rates in vitro, displaying increased tumor growth and reduced survival rates in xenotransplanted nude mice. This phenotype is accompanied by the upregulation of EMT-related genes Slug, Snail, TGFBR2, vimentin, N-cadherin, MMP-2, MMP-9, and MMP-14. However, these effects were not observed in the MCF-7 cells overexpressing FAM3B.

CONCLUSION

FAM3B overexpression contributes to tumor growth, promotion of metastasis, and, consequently, leads to a poor prognosis in the most aggressive forms of breast cancer. Future clinical research is necessary to validate FAM3B as both a diagnostic and a therapeutic strategy for TNBC.

Iron Overload Induces Hepatic Ferroptosis and Insulin Resistance by Inhibiting the Jak2/stat3/slc7a11 Signaling Pathway

Recent studies showed that patients with iron overload had increased risk of insulin resistance or diabetes. Ferroptosis is a new type of cell death mainly caused by iron-dependent oxidative damage. In the present study, we investigated potential mechanisms of iron overload induced hepatic ferroptosis and insulin resistance through in vivo and in vitro experiments. In vivo, the mice models of iron overload were established by intraperitoneal injection of iron dextran. The changes of body weight, serum ferritin and blood glucose were measured. Hematoxylin-eosin (HE) and Perl's stainings were used to observe the pathological changes and iron deposition in the liver of mice. In vitro, HepG2 cells were treated with ferric ammonium citrate (FAC, 9 mmol/L, 24 h) to establish the cell models of iron overload. The labile iron pool, cell viability, glucose consumption and glycogen contents were measured. The ultrastructure of mitochondria was observed by transmission electron microscope (TEM). The malondialdehyde (MDA) and glutathione (GSH) kits were used to detect lipid peroxidation in liver tissues of mice and HepG2 cells. RT-PCR and Western blot were used to detect the mRNA and protein expression levels of ferroptosis factors and JAK2/STAT3 signaling pathway. In this study, we used the iron chelator deferasirox in mice and HepG2 cells. Iron overload caused weight loss, elevated serum ferritin, fasting blood glucose, fasting insulin, HOMA-IR, impaired glucose tolerance, and decreased insulin sensitivity in mice. HE staining and Perls staining showed clumps of iron deposition in the liver of iron overload mice. Iron overload could reduce the glucose consumption, increase MDA contents of HepG2 cells, while reduce glycogen and GSH contents in liver tissues of mice and HepG2 cells. TEM showed deletion of mitochondrial ridge and rupture of outer membrane in HepG2 cells with iron overload. Iron chelator deferasirox could significantly improve the above indicators, which might be related to the activation of JAK2/STAT3/SLC7A11 signaling pathway and hepatic ferroptosis. Iron overload could induce hepatic ferroptosis and insulin resistance by inhibiting the JAK2/STAT3/SLC7A11 signaling pathway, and the iron chelator deferasirox might improve hepatic insulin resistance induced by iron overload.

Olink Proteomics-Based Exploration of Immuno-Oncology-Related Biomarkers Leading to Lung Adenocarcinoma Progression

INTRODUCTION

It is crucial to investigate the distinct proteins that contribute to the advancement of lung cancer.

MATERIAL AND METHODS

We analyzed the expression levels of 92 immuno-oncology-related proteins in 96 pairs of lung adenocarcinoma tissue samples using Olink proteomics. The differentially expressed proteins (DEPs) were successively screened in tumor and paraneoplastic groups, early and intermediate-late groups by a nonparametric rank sum test, and the distribution and expression levels of DEPs were determined by volcano and heat maps, etc., and the area under the curve was calculated.

RESULTS

A total of 24 DEPs were identified in comparisons between tumor and paracancerous tissues. Among them, interleukin-8 (IL8) and chemokine (C-C motif) ligand 20 (CCL20) as potential markers for distinguishing tumor tissues. Through further screening, it was found that interleukin-6 (IL6) and vascular endothelial growth factor A (VEGFA) may be able to lead to tumor progression through the JaK-STAT signaling pathway, Toll-like receptor signaling pathway and PI3K/AKT signaling pathway. Interestingly, our study revealed a down-regulation of IL6 and VEGFA in tumor tissues compared to paracancerous tissues.

CONCLUSIONS

IL8 + CCL20 (AUC: 0.7056) have the potential to differentiate tumor tissue from paracancerous tissue; IL6 + VEGFA (AUC: 0.7531) are important protein markers potentially responsible for tumor progression.

Iron Chelator Deferiprone Restores Iron Homeostasis and Inhibits Retinal Neovascularization in Experimental Neovascular Age-Related Macular Degeneration

Purpose

Retinal neovascularization is a significant feature of advanced age-related macular degeneration (AMD) and a major cause of blindness in patients with AMD. However, the underlying mechanism of this pathological neovascularization remains unknown. Iron metabolism has been implicated in various biological processes. This study was conducted to investigate the effects of iron metabolism on retinal neovascularization in neovascular AMD (nAMD).

Methods

C57BL/6J and very low-density lipoprotein receptor (VLDLR) knockout (Vldlr-/-) mice, a murine model of nAMD, were used in this study. Bulk-RNA sequencing was used to identify differentially expressed genes. Western blot analysis was performed to test the expression of proteins. Iron chelator deferiprone (DFP) was administrated to the mice by oral gavage. Fundus fluorescein angiography was used to evaluate retinal vascular leakage. Immunofluorescence staining was used to detect macrophages and iron-related proteins.

Results

RNA sequencing (RNA-seq) results showed altered transferrin expression in the retina and RPE of Vldlr-/- mice. Disrupted iron homeostasis was observed in the retina and RPE of Vldlr-/- mice. DFP mitigated iron overload and significantly reduced retinal neovascularization and vascular leakage. In addition, DFP suppressed the inflammation in Vldlr-/- retinas. The reduced signals of macrophages were observed at sites of neovascularization in the retina and RPE of Vldlr-/- mice after DFP treatment. Further, the IL-6/JAK2/STAT3 signaling pathway was activated in the retina and RPE of Vldlr-/- mice and reversed by DFP treatment.

Conclusions

Disrupted iron metabolism may contribute to retinal neovascularization in nAMD. Restoring iron homeostasis by DFP could be a potential therapeutic approach for nAMD.

Bone marrow adipocytes and lung cancer bone metastasis: unraveling the role of adipokines in the tumor microenvironment

Bone is a common site of metastasis for lung cancer. The "seed and soil" hypothesis suggests that the bone marrow microenvironment ("soil") may provide a conducive survival environment for metastasizing tumor cells ("seeds"). The bone marrow microenvironment, comprising a complex array of cells, includes bone marrow adipocytes (BMAs), which constitute about 70% of the adult bone marrow volume and may play a significant role in tumor bone metastasis. BMAs can directly provide energy for tumor cells, promoting their proliferation and migration. Furthermore, BMAs participate in the tumor microenvironment's osteogenesis regulation, osteoclast(OC) regulation, and immune response through the secretion of adipokines, cytokines, and inflammatory factors. However, the precise mechanisms of BMAs in lung cancer bone metastasis remain largely unclear. This review primarily explores the role of BMAs and their secreted adipokines (leptin, adiponectin, Nesfatin-1, Resistin, chemerin, visfatin) in lung cancer bone metastasis, aiming to provide new insights into the mechanisms and clinical treatment of lung cancer bone metastasis.

Overexpression of SOCS2 Inhibits EMT and M2 Macrophage Polarization in Cervical Cancer via IL-6/JAK2/STAT3 Pathway

OBJECTIVE

SOCS2 is a member of the suppressor of cytokine signaling (SOCS) protein family associated with the occurrence and development of multiple cancers. This study revealed the expression and molecular mechanisms of SOCS2 in cervical cancer.

METHODS

In this study, RT-qPCR, Western Blot, and immunohistochemistry were used to detect the expression level of SOCS2 in cervical cancer tissues and tumor cells. We overexpressed SOCS2 in SiHa cells via lentivirus. In-vitro experiments were used to investigate the changes in cervical cancer cell proliferation, migration, and invasion ability before and after SOCS2 overexpression. Western Blot was used to detect the expression of IL-6/JAK2/STAT3 pathway and EMTrelated proteins. M0 macrophages were co-cultured with the tumor-conditioned medium. The effect of SOCS2 on macrophage polarization was examined by RT-qPCR.

RESULTS

SOCS2 expression level was significantly downregulated in cervical cancer tissues. SOCS2 was negatively correlated with CD163+M2 macrophages. Overexpression of SOCS2 inhibited the proliferation, migration, and invasion of cervical cancer cells. The expressions of Twist- 2, N-cadherin, and Vimentin were decreased, while the expression of E-cadherin was increased. Moreover, the expression of IL-6, p-JAK2, and p-STAT3 were decreased. After the addition of RhIL-6, the expression of E-cadherin protein in the LV-SOCS2 group was reversed. CM in the LV-SOCS2 group inhibited the polarization of M2 macrophages.

CONCLUSION

SOCS2 acts as a novel biological target and suppressor of cervical cancer through IL- 6/JAK2/STAT3 pathway.

Depletion of Labile Iron Induces Replication Stress and Enhances Responses to Chemoradiation in Non-Small-Cell Lung Cancer

The intracellular redox-active labile iron pool (LIP) is weakly chelated and available for integration into the iron metalloproteins that are involved in diverse cellular processes, including cancer cell-specific metabolic oxidative stress. Abnormal iron metabolism and elevated LIP levels are linked to the poor survival of lung cancer patients, yet the underlying mechanisms remain unclear. Depletion of the LIP in non-small-cell lung cancer cell lines using the doxycycline-inducible overexpression of the ferritin heavy chain (Ft-H) (H1299 and H292), or treatment with deferoxamine (DFO) (H1299 and A549), inhibited cell growth and decreased clonogenic survival. The Ft-H overexpression-induced inhibition of H1299 and H292 cell growth was also accompanied by a significant delay in transit through the S-phase. In addition, both Ft-H overexpression and DFO in H1299 resulted in increased single- and double-strand DNA breaks, supporting the involvement of replication stress in the response to LIP depletion. The Ft-H and DFO treatment also sensitized H1299 to VE-821, an inhibitor of ataxia telangiectasis and Rad2-related (ATR) kinase, highlighting the potential of LIP depletion, combined with DNA damage response modifiers, to alter lung cancer cell responses. In contrast, only DFO treatment effectively reduced the LIP, clonogenic survival, cell growth, and sensitivity to VE-821 in A549 non-small-cell lung cancer cells. Importantly, the Ft-H and DFO sensitized both H1299 and A549 to chemoradiation in vitro, and Ft-H overexpression increased the efficacy of chemoradiation in vivo in H1299. These results support the hypothesis that the depletion of the LIP can induce genomic instability, cell death, and potentiate therapeutic responses to chemoradiation in NSCLC.

DLGAP5 Regulates the Proliferation, Migration, Invasion, and Cell Cycle of Breast Cancer Cells via the JAK2/STAT3 Signaling Axis

The aim of this study was to discover new biomarkers to detect breast cancer (BC), which is an aggressive cancer with a high mortality rate. In this study, bioinformatic analyses (differential analysis, weighted gene co-expression network analysis, and machine learning) were performed to identify potential candidate genes for BC to study their molecular mechanisms. Furthermore, Quantitative Real-time PCR and immunohistochemistry assays were used to examine the protein and mRNA expression levels of a particular candidate gene (DLGAP5). And the effects of DLGAP5 on cell proliferation, migration, invasion, and cell cycle were further assessed using the Cell Counting Kit-8 assay, colony formation, Transwell, wound healing, and flow cytometry assays. Moreover, the changes in the JAK2/STAT3 signaling-pathway-related proteins were detected by Western Blot. A total of 44 overlapping genes were obtained by differential analysis and weighted gene co-expression network analysis, of which 25 genes were found in the most tightly connected cluster. Finally, NEK2, CKS2, UHRF1, DLGAP5, and FAM83D were considered as potential biomarkers of BC. Moreover, DLGAP5 was highly expressed in BC. The down-regulation of DLGAP5 may inhibit the proliferation, migration, invasion, and cell cycle of BC cells, and the opposite was true for DLGAP5 overexpression. Correspondingly, silencing or overexpression of the DLGAP5 gene inhibited or activated the JAK2/STAT3 signaling pathway, respectively. DLGAP5, as a potential biomarker of BC, may impact the cell proliferation, migration, invasion, cell cycle, and BC development by modulating the JAK2/STAT3 signaling pathway.

Hydrazinocurcumin Induced Autophagy and Affected Cell Proliferation by Downregulating the JAK/STAT3 Signaling Pathway in Skin Squamous Cell Carcinoma

This study aims to investigate the relevant mechanism by which hydrazinocurcumin (HC) interferes with A431 cell autophagy by inhibiting the STAT3 signaling pathway. Different concentrations of HC are used to treat A431 cells to study the effects of HC on A431 cell proliferation and apoptosis. Real-time fluorescent quantitative polymerase chain reaction (PCR) is used to further explore the relationship of HC with the JAK signaling pathway and autophagy. Double immunofluorescence staining is used to detect the fluorescence localization of LC3 and STAT3 after HC treatment. With increasing HC concentrations, A431 cell viability decreases in a dose-dependent manner, and the apoptosis rate increases significantly. Laser confocal colocalization reveals that the fluorescence of labeled LC3 protein is significantly increased, and the fluorescence of labeled STAT3 is significantly reduced in this study. HC may induce autophagy in A431 cells and affect cell proliferation by downregulating the JAK/STAT3 signaling pathway.

Comparison of Interleukin-6 with Other Markers in Diagnosis of Ovarian Cancer

The lack of specific symptoms in ovarian cancer delays onset of the diagnostic process. Hence, most cases are recognized in late stages of the disease. The aim of this study was to confirm the role of Il-6 compared to other markers in diagnosis and survival in ovarian cancer. The database was collected from 13 January 2021 to 15 February 2023. In total, 101 patients with pelvic tumors with a mean age of 57.86 ± 16.39 participated in the study. In every case, CA125, HE4, CEA, CA19-9, Il-6, C-reactive protein and procalcitonin measurements were taken. Patients with ovarian borderline tumor and metastatic ovarian tumors were excluded from further analysis. Statistically significant correlations were found between diagnosis of ovarian cancer and levels of CA125, HE4, CRP, PCT and Il-6. Comparison of Il-6 with other markers revealed that longer overall survival correlated with lower values of Il-6. In the case of a higher concentration of Il-6, OS and PFS were shorter. Sensitivity and specificity of Il-6 in diagnosis of ovarian cancer were 46.8% and 77.8%, respectively, while for CA125, CRP and PCT were 76.6% and 63%; 68% and 57.5%; 36% and 77%, respectively. More investigations are needed to identify the most specific and sensitive marker for ovarian cancer.

VSIG4 Silencing Inhibits Glioblastoma Growth by Regulating the JAK2/STAT3 Pathway

Background

Glioblastoma (GBM) is the most common malignant primary brain tumour in adults. VSIG4 has been identified to be associated with GBM. We aimed to determine the downstream regulatory mechanisms of VSIG4 in GBM.

Methods

Differential expression of VSIG4 was analysed using GEPIA. The expression of VSIG4 was assessed by RT-qPCR and its downstream genes were screened by transcriptome sequencing. The expression of pyroptosis-related proteins and the JAK2/STAT3 pathway was measured by Western blotting. GBM cell viability, migration, and invasion were detected using CCK-8, scratch, and Transwell assays. The levels of pyroptosis-related factors were measured using ELISA. The effect of VSIG4 on GBM tumour growth in vivo was explored by constructing a xenograft tumour model.

Results

VSIG4 expression was upregulated in GBM. Functionally, silencing of VSIG4 inhibited proliferation, invasion, and migration of U251 and LN229 cells, and promoted pyroptosis. Mechanically, transcriptome sequencing revealed that the JAK2/STAT3 pathway might be a downstream regulator of VSIG4. Further studies proved that silencing of VSIG4 enhanced the expression of p-JAK2 and p-STAT3, and the JAK2/STAT3 pathway inhibitor relieved the suppression of VSIG4 silencing on GBM cell viability, invasion, and migration. Furthermore, in vivo experiments further validated that knockdown of VSIG4 inhibited the growth of GBM tumors.

Conclusion

In GBM, silencing VSIG4 promoted pyroptosis and inhibited tumor progression by regulating the JAK2/STAT3 signaling pathway.

MicroRNA let-7d attenuates hypertrophic scar fibrosis through modulation of iron metabolism by reducing DMT1 expression

Hypertrophic scar is an unavoidable result of wound healing following burns and trauma, which remains a challenging problem for clinicians. Previously, we demonstrated that exosomal microRNAs (miRs) of human amniotic epithelial cells accelerated wound healing and inhibited scar formation. However, the underlying mechanism is still unclear. In this particular study, we found that miR-let-7d reduced collagen deposition, and this was accompanied by decreased level of iron content in myofibroblasts. Importantly, inhibition of miR-let-7d in myofibroblasts accelerated collagen deposition and promoted cell proliferation. In addition, bioinformatics prediction combined with classical dual-luciferase reporter gene assay demonstrated that the cellular iron importer divalent metal transporter 1 (DMT1) was a target gene of miR-let-7d, and the miR-let-7d mimics inhibited the expression of DMT1 in myofibroblasts. Moreover, silencing of DMT1 with small interfering RNA (siRNA) reduced the deposition of extracellular matrix. Consistent with the results in vitro, the miR-let-7d mimics effectively ameliorated hypertrophic scar fibrosis in a rabbit ear hypertrophic scar model. Taken together, our results indicated for the first time that miR-let-7d attenuated hypertrophic scar fibrosis through modulation of iron metabolism by reducing iron uptake through DMT1, which may provide a novel therapeutic strategy for hypertrophic scar.

The role of IL-6/JAK2/STAT3 signaling pathway in cancers

Interleukin-6 (IL-6) is a pleiotropic cytokine involved in immune regulation. It can activate janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) signaling pathway. As one of the important signal transduction pathways in cells, JAK2/STAT3 signaling pathway plays a critical role in cell proliferation and differentiation by affecting the activation state of downstream effector molecules. The activation of JAK2/STAT3 signaling pathway is involved in tumorigenesis and development. It contributes to the formation of tumor inflammatory microenvironment and is closely related to the occurrence and development of many human tumors. This article focuses on the relationship between IL-6/JAK2/STAT3 signaling pathway and liver cancer, breast cancer, colorectal cancer, gastric cancer, lung cancer, pancreatic cancer and ovarian cancer, hoping to provide references for the research of cancer treatment targeting key molecules in IL-6/JAK2/STAT3 signaling pathway.

Ferroptosis and triple-negative breast cancer: Potential therapeutic targets

Purpose

Triple-negative breast cancer (TNBC) is an aggressive tumor with poor prognosis, it has higher recurrence and metastatic rates than other breast cancer subtypes. This study aims to investigate biomarkers and potential targets for TNBC related to ferroptosis through data mining and bioinformatics analysis. The findings may provide new insights for treating TNBC.

Methods

The TNBC patients' data from the Cancer Genome Atlas (TCGA) database were extracted for differential expression and prognosis analysis. Consensus genes obtained by intersecting differential expressed and ferroptosis-related genes was used to establish the prognostic model by the univariate and multivariate Cox analyses. Besides, TNBC data from the Gene Expression Omnibus (GEO) database was used to confirm the reliability of the prognosis model. Moreover, clinical information was analyzed by multifactorial independent analysis to identify independent prognostic factors. The expression of genes constituting the prognostic model was further validated using the Human Protein Atlas (HPA) database. Finally, the Comparative Toxicogenomic Data (CTD) database was used to explore possible treatment drugs for TNBC.

Results

We obtained 13,245 differential expressed genes, and 177 consensus genes. 98 genes with prognostic implication were obtained by univariable Cox. Then, a prognostic model including 12 ferroptosis-related genes was constructed by multivariable Cox. The area under curve (AUC) value of the prognostic model for TNBC was 0.82. The GEO database validated that the model (AUC = 0.77) could predict the patient outcomes. The staining results of 10 out of 12 prognostic model genes in HPA database showed that their expression was consistent with our predictions. Clinical risk analysis indicated that risk score of patients could act as an independent prognostic factor. Finally, six drugs that may have interaction with 12 ferroptosis-related genes were obtained using the CTD database.

Conclusion

The prognostic model composed of 12 ferroptosis-related genes could predict the prognosis of TNBC patients, and seven genes (ASNS, LAMP2, CAV1, DPP4, HELLS, TF, ZFP69B) could be potential new therapeutic targets for TNBC, and two drugs (1-methyl-3-isobutylxanthine, rosiglitazone) could act as potential therapeutic drugs for the treatment of TNBC.

TRIM65 Promotes Malignant Cell Behaviors in Triple-Negative Breast Cancer by Impairing the Stability of LATS1 Protein

TNBC is a malignant tumor that easily relapses and metastasizes, with a poor prognosis in women. Ubiquitination plays a key role in promoting the tumor process. In various tumors, TRIM65 can affect malignant biological tumor behavior by ubiquitination of related proteins. We aimed to investigate TRIM65 expression in TNBC and whether it promotes malignant biological behavior in TNBC cells using Cell Counting Kit-8, colony formation, and transwell assays. Mechanically, we confirmed that TRIM65 promoted TNBC invasion and metastasis by ubiquitination of LATS1 protein through Co-IP, CHX, and endogenous ubiquitination experiments. The expression of TRIM65 was abnormally high and accelerated the proliferation, invasion, and migration of MDA-MB-231 and MDA-MB-453 cells. In vivo animal experiments also revealed that TRIM65 accelerated TNBC cell proliferation. Mechanistically, TRIM65 degraded LATS1 protein expression through ubiquitination in the Co-IP, CHX, and endogenous ubiquitination experiments. Rescue assays confirmed that TRIM65 degraded LATS1 protein expression, accelerating the proliferation, invasion, and migration ability of TNBC cells. Our results show that TRIM65 is upregulated in TNBC, and TRIM65 degrades LATS1 protein expression through ubiquitination and promotes malignant biological behavior in TNBC cells. TRIM65 may play an important role as a new oncogene in TNBC.

Iron Overload and Breast Cancer: Iron Chelation as a Potential Therapeutic Approach

Breast cancer has historically been one of the leading causes of death for women worldwide. As of 2020, breast cancer was reported to have overtaken lung cancer as the most common type of cancer globally, representing an estimated 11.3% of all cancer diagnoses. A multidisciplinary approach is taken for the diagnosis and treatment of breast cancer that includes conventional and targeted treatments. However, current therapeutic approaches to treating breast cancer have limitations, necessitating the search for new treatment options. Cancer cells require adequate iron for their continuous and rapid proliferation. Excess iron saturates the iron-binding capacity of transferrin, resulting in non-transferrin-bound iron (NTBI) that can catalyze free-radical reactions and may lead to oxidant-mediated breast carcinogenesis. Moreover, excess iron and the disruption of iron metabolism by local estrogen in the breast leads to the generation of reactive oxygen species (ROS). Therefore, iron concentration reduction using an iron chelator can be a novel therapeutic strategy for countering breast cancer development and progression. This review focuses on the use of iron chelators to deplete iron levels in tumor cells, specifically in the breast, thereby preventing the generation of free radicals. The inhibition of DNA synthesis and promotion of cancer cell apoptosis are the targets of breast cancer treatment, which can be achieved by restricting the iron environment in the body. We hypothesize that the usage of iron chelators has the therapeutic potential to control intracellular iron levels and inhibit the breast tumor growth. In clinical settings, iron chelators can be used to reduce cancer cell growth and thus reduce the morbidity and mortality in breast cancer patients.

Relationships Between Biological Heavy Metals and Breast Cancer: A Systematic Review and Meta-Analysis

Introduction

Heavy metals were classified as essential, probably essential, and potentially toxic in the general population. Until now, it has been reported inconsistently on the association between heavy metals and BC. In this meta-analysis, we aimed to assess the association between heavy metals and BC and review the potential mechanisms systematically.

Methods

We searched for epidemiological studies in English about the association between heavy metals and BC published before September 2020 in PubMed, Web of Science, and Embase databases. In total 36 studies, comprising 4,151 individuals from five continents around the world were identified and included.

Results

In all biological specimens, Cu, Cd, and Pb concentrations were higher, but Zn and Mn concentrations were lower in patients with BC than in non-BC participants [SMD (95% CIs): 0.62 (0.12, 1.12); 1.64 (0.76, 2.52); 2.03 (0.11, 3.95); −1.40 (−1.96, −0.85); −2.26 (−3.39, −1.13); p = 0.01, 0.0003, 0.04, <0.0001, <0.0001]. Specifically, higher plasma or serum Cu and Cd, as well as lower Zn and Mn, were found in cases [SMD (95% CIs): 0.98 (0.36, 1.60); 2.55 (1.16, 3.94); −1.53 (−2.28, −0.78); −2.40 (−3.69, −1.10); p = 0.002, 0.0003, <0.0001, 0.0003]; in hair, only lower Zn was observed [SMD (95% CIs): −2.12 (−3.55, −0.68); p = 0.0004]. Furthermore, the status of trace elements probably needs to be re-explored, particularly in BC. More prospective studies, randomized clinical trials, and specific pathogenic studies are needed to prevent BC. The main mechanisms underlying above-mentioned findings are comprehensively reviewed.

Conclusion

For BC, this review identified the current knowledge gaps which we currently have in understanding the impact of different heavy metals on BC.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020176934, identifier: CRD42020176934.

Mitochondria in tumour progression: a network of mtDNA variants in different types of cancer

Background

Mitochondrial participation in tumorigenesis and metastasis has been studied for many years, but several aspects of this mechanism remain unclear, such as the association of mitochondrial DNA (mtDNA) with different cancers. Here, based on two independent datasets, we modelled an mtDNA mutation-cancer network by systematic integrative analysis including 37 cancer types to identify the mitochondrial variants found in common among them.

Results

Our network showed mtDNA associations between gastric cancer and other cancer types, particularly kidney, liver, and prostate cancers, which is suggestive of a potential role of such variants in the metastatic processes among these cancer types. A graph-based interactive web tool was made available at www2.lghm.ufpa.br/mtdna. We also highlighted that most shared variants were in the MT-ND4, MT-ND5 and D-loop, and that some of these variants were nonsynonymous, indicating a special importance of these variants and regions regarding cancer progression, involving genomic and epigenomic alterations.

Conclusions

This study reinforces the importance of studying mtDNA in cancer and offers new perspectives on the potential involvement of different mitochondrial variants in cancer development and metastasis.

Non-coding RNA-based regulation of inflammation

Inflammation is a multifactorial process and various biological mechanisms and pathways participate in its development. The presence of inflammation is involved in pathogenesis of different diseases such as diabetes mellitus, cardiovascular diseases and even, cancer. Non-coding RNAs (ncRNAs) comprise large part of transcribed genome and their critical function in physiological and pathological conditions has been confirmed. The present review focuses on miRNAs, lncRNAs and circRNAs as ncRNAs and their potential functions in inflammation regulation and resolution. Pro-inflammatory and anti-inflammatory factors are regulated by miRNAs via binding to 3'-UTR or indirectly via affecting other pathways such as SIRT1 and NF-κB. LncRNAs display a similar function and they can also affect miRNAs via sponging in regulating levels of cytokines. CircRNAs mainly affect miRNAs and reduce their expression in regulating cytokine levels. Notably, exosomal ncRNAs have shown capacity in inflammation resolution. In addition to pre-clinical studies, clinical trials have examined role of ncRNAs in inflammation-mediated disease pathogenesis and cytokine regulation. The therapeutic targeting of ncRNAs using drugs and nucleic acids have been analyzed to reduce inflammation in disease therapy. Therefore, ncRNAs can serve as diagnostic, prognostic and therapeutic targets in inflammation-related diseases in pre-clinical and clinical backgrounds.

Significance of glutathione peroxidase 4 and intracellular iron level in ovarian cancer cells-"utilization" of ferroptosis mechanism

OBJECTIVE AND DESIGN

Ovarian cancer is the major cause of death in gynecologic diseases worldwide. Ferroptosis, a nonapoptotic form of cell death, is featured by accumulation of iron-based lipid peroxidation. The elevated iron level and malondialdehyde (MDA) in ovarian cancer cells suggest more vulnerable to ferroptosis, nevertheless, ferroptosis is not observed in ovarian cancer cells. Glutathione peroxidase 4 (GPX4) is a critical regulator of ferroptosis.

METHODS

We determined whether GPX4 knockdown could induce ferroptosis to prevent cell proliferation in ovarian cancer. Human ovarian cancer cells and normal human ovarian epithelial cell line IOSE-80 were cultured and administrated with deferoxamine (DFO) or ferric ammonium citrate (FAC). GPX4 knockdown was established for investigating the functions of GPX4 in ovarian cancer cells and in tumor xenograft mice.

RESULTS

A positively correlation was showed among the levels of GPX4, iron and cell proliferation. Chelation of intracellular iron by DFO disrupted intracellular iron level and was detrimental to ovarian cancer cell survival. FAC-induced elevation of intracellular iron inhibited proliferation, aggravated apoptosis, boosted inflammation and suppressed lipid peroxide reducibility in ovarian cancer cells. Knockdown of GPX4 had similar effects with FAC in ovarian cancer cells. Inhibition of GPX4 suppressed tumor growth, induced ferroptosis, accelerated cell apoptosis, reduced Fe3+ accumulation and suppressed lipid peroxide reducibility in tumor bearing mice.

CONCLUSION

We demonstrate the significance of GPX4 and intracellular iron level in ovarian cancer cells. Importantly, inhibition of GPX4 interferes with both intracellular iron homeostasis and lipid peroxide reducibility, inducing ferroptosis and exerting anti-cancer effect, which can be a potential effective strategy for ovarian cancer therapy.

Associations of iron status with breast cancer risk factors in adult women: Findings from National Health and Nutrition Examination Survey 2017-2018

OBJECTIVE

This study examined the association between iron status and a set of breast cancer risk factors among U.S. adult women aged 20-80 years.

METHODS

Data from National Health and Nutrition Examination Survey (2017-2018) were used to examine the relation between serum ferritin, serum iron and transferrin saturation with a set of breast cancer risk factors [body mass index (BMI), waist circumference, glycosylated hemoglobin (HbA1c), fasting plasma glucose, insulin and HOMA-IR]. The multivariable linear regressions were used controlling for age, race/ethnicity, menopause status, education level, smoking status, alcohol consumption, physical activity, high-sensitivity C-reactive protein (hsCRP) and total energy intake.

RESULTS

HbA1c, BMI and waist circumference data were available for 1902 women with a fasting sample (n = 913) for fasting plasma glucose, insulin and HOMA-IR. Transferrin saturation had significant, inverse associations with BMI, waist circumference and HbA1c. The size of difference observed were that participants in the fourth quartile of transferrin saturation had a 4.50 kg/m² smaller BMI, a 9.36 cm smaller waist circumference and a 0.1 % lower HbA1c level than participants in the first quartile. Similarly, serum iron concentrations were inversely associated with BMI and waist circumference. In addition, serum iron had significant, inverse associations with insulin and HOMA-IR. Sensitivity analyses among men gave similar results. For serum ferritin, there was a trend towards a positive association between waist circumference, HbA1c and fasting plasma glucose with serum ferritin. However, the associations did not reach statistical significance among women.

CONCLUSIONS

Iron status may impact breast cancer risk via effects on adiposity or glucose metabolism. The findings should be confirmed with further prospective data.

Pre-Clinical Insights into the Iron and Breast Cancer Hypothesis

Population studies, systematic reviews, and meta-analyses have revealed no relationship between iron status and breast cancer, a weak positive association, or a small protective effect of low iron status. However, in those studies, the authors concluded that further investigation was merited. The set of experiments reported here used preclinical models to assess the likely value of further investigation. The effects of iron status on the initiation and promotion stage of mammary carcinogenesis are reported. Using the classical model of cancer initiation in the mammary gland, 7,12 dimethyl-benz[α]anthracene-induced carcinogenesis was unaffected by iron status. Similarly, excess iron intake showed no effect on the promotion stage of 1-methyl-1-nitrosurea-induced mammary carcinogenesis, though iron deficiency exerted a specific inhibitory effect on the carcinogenic process. Though iron-mediated cellular oxidation is frequently cited as a potential mechanism for effects on breast cancer, no evidence of increased oxidative damage to DNA attributable to excess iron intake was found. The reported preclinical data fail to provide convincing evidence that the further evaluation of the iron–breast cancer risk hypotheses is warranted and underscore the value of redefining the referent group in population-based studies of iron–cancer hypotheses in other tissues.

Requirement of Histone Deacetylase 6 for Interleukin-6 Induced Epithelial-Mesenchymal Transition, Proliferation, and Migration of Peritoneal Mesothelial Cells

Aims: Influenced by microenvironment, human peritoneal mesothelial cells (HPMCs) acquired fibrotic phenotype, which was identified as the protagonist for peritoneal fibrosis. In this study, we examined the role of histone deacetylase 6 (HDAC6) for interleukin-6 (IL-6) induced epithelial-mesenchymal transition (EMT), proliferation, and migration of HPMCs. Methods: The role of HDAC6 in IL-6-elicited EMT of HPMCs was tested by morphological observation of light microscope, immunoblotting, and immune-fluorescence assay; and the function of HDAC6 in proliferation and migration of HPMCs was examined by CCK-8 assay, wound healing experiment, and immunoblotting. Results: IL-6 stimulation significantly increased the expression of HDAC6. Treatment with tubastatin A (TA), a highly selective HDAC6 inhibitor, or silencing of HDAC6 with siRNA decreased the expression of HDAC6. Moreover, TA or HDAC6 siRNA suppressed IL-6-induced EMT, as evidenced by decreased expressions of α-SMA, Fibronectin, and collagen I and the preserved expression of E-cadherin in cultured HPMCs. Mechanistically, HDAC6 inhibition suppressed the expression of transforming growth factor β (TGFβ) receptor I (TGFβRI), phosphorylation of Smad3, secretion of connective tissue growth factor (CTGF), and transcription factor Snail. On the other hand, the pharmacological inhibition or genetic target of HDAC6 suppressed HPMCs proliferation, as evidenced by the decreased optical density of CCK-8 and the expressions of PCNA and Cyclin E. The migratory rate of HPMCs also decreased. Mechanistically, HDAC6 inhibition blocked the activation of JAK2 and STAT3. Conclusion: Our study illustrated that IL-6-induced HDAC6 not only regulated IL-6 itself downstream JAK2/STAT3 signaling but also co-activated the TGF-β/Smad3 signaling, leading to the change of the phenotype and mobility of HPMCs. HDAC6 could be a potential therapeutic target for the prevention and treatment of peritoneal fibrosis.

Combination therapy of tanshinone IIA and puerarin for pulmonary fibrosis via targeting IL6-JAK2-STAT3/STAT1 signaling pathways

Efficient therapy of idiopathic pulmonary fibrosis (IPF) is still a major challenge. The current studies with single-target drug therapy are the pessimistic approaches due to the complex characteristics of IPF. Here, a combination therapy of Tanshinone IIA and Puerarin for IPF was proposed to alleviate IPF due to their antiinflammatory and anti-fibrotic effects. In vivo, the combination therapy could significantly attenuate the area of ground glass opacification that was presented by 85% percentile density score of the micro-CT images when compared to single conditions. In addition, the combination therapy enormously improved the survival rate and alleviated pathological changes in bleomycin (BLM)-induced IPF mice. By using a wide spectrum of infiltration biomarkers in immunofluorescence assay in pathological sections, we demonstrate that fewer IL6 related macrophage infiltration and fibrosis area after this combination therapy, and further proved that IL6-JAK2-STAT3/STAT1 is the key mechanism of the combination therapy. In vitro, combination therapy markedly inhibited the fibroblasts activation and migration which was induced by TGF-β1 or/and IL6 through JAK2-STAT3/STAT1 signaling pathway. This study demonstrated that combination therapeutic effect of TanIIA and Pue on IPF may be related to the reduced inflammatory response targeting IL6, which could be an optimistic and effective approach for IPF.

Single-cell analysis reveals metastatic cell heterogeneity in clear cell renal cell carcinoma

Renal cell carcinoma (RCC) is one of the leading causes of cancer-related death worldwide. Tumour metastasis and heterogeneity lead to poor survival outcomes and drug resistance in patients with metastatic RCC (mRCC). In this study, we aimed to assess intratumoural heterogeneity (ITH) in mRCC cells by performing a combined analysis of bulk data and single-cell RNA-sequencing data, and develop novel biomarkers for prognosis prediction on the basis of the potential molecular mechanisms underlying tumorigenesis. Eligible single-cell cohorts related to mRCC were acquired using the Gene Expression Omnibus (GEO) dataset to identify potential mRCC subpopulations. We then performed gene set variation analysis to understand the differential function in primary RCC and mRCC samples. Subsequently, we applied weighted correlation network analysis to identify coexpressing gene modules that were related to the external trait of metastasis. Protein-protein interactions were used to screen hub subpopulation-difference (sub-dif) markers (ACTG1, IL6, CASP3, ACTB and RAP1B) that might be involved in the regulation of RCC metastasis and progression. Cox regression analysis revealed that ACTG1 was a protective factor (HR < 1), whereas the other four genes (IL6, CASP3, ACTB and RAP1B) were risk factors (HR > 1). Kaplan-Meier survival analysis suggested the potential prognostic value of these sub-dif markers. The expression of sub-dif markers in mRCC was further evaluated in clinical samples by immunohistochemistry (IHC). Additionally, the genetic features of sub-dif marker expression patterns, such as genetic variation profiles, correlations with tumour-infiltrating lymphocytes (TILs), and targeted signalling pathway activities, were assessed in bulk RNA-seq datasets. In conclusion, we established novel subpopulation markers as key prognostic factors affecting EMT-related signalling pathway activation in mRCC, which could facilitate the implementation of a treatment for mRCC patients.

Tailored-Made Polydopamine Nanoparticles to Induce Ferroptosis in Breast Cancer Cells in Combination with Chemotherapy

Ferroptosis is gaining followers as mechanism of selective killing cancer cells in a non-apoptotic manner, and novel nanosystems capable of inducing this iron-dependent death are being increasingly developed. Among them, polydopamine nanoparticles (PDA NPs) are arousing interest, since they have great capability of chelating iron. In this work, PDA NPs were loaded with Fe3+ at different pH values to assess the importance that the pH may have in determining their therapeutic activity and selectivity. In addition, doxorubicin was also loaded to the nanoparticles to achieve a synergist effect. The in vitro assays that were performed with the BT474 and HS5 cell lines showed that, when Fe3+ was adsorbed in PDA NPs at pH values close to which Fe(OH)3 begins to be formed, these nanoparticles had greater antitumor activity and selectivity despite having chelated a smaller amount of Fe3+. Otherwise, it was demonstrated that Fe3+ could be released in the late endo/lysosomes thanks to their acidic pH and their Ca2+ content, and that when Fe3+ was co-transported with doxorubicin, the therapeutic activity of PDA NPs was enhanced. Thus, reported PDA NPs loaded with both Fe3+ and doxorubicin may constitute a good approach to target breast tumors.