Increased serum hepcidin-25 level and increased tumor expression of hepcidin mRNA are associated with metastasis of renal cell carcinoma

A prognostic model based on tumor microenvironment and immune cell in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer-related death. Immunotherapy is one of the new options for cancer treatment. This study aimed to develop an immune-related signature associated with CRC.

METHODS

We performed differential analysis to screen out the differentially expressed genes (DEGs) of The Cancer Genome Atlas-Colorectal Cancer (TCGA-CRC) datasets. Weighted gene co-expression network analysis (WGCNA) was performed to obtain the key module genes associated with differential immune cells. The candidate genes were obtained through overlapping key DEGs and key module genes. The univariate and multivariate Cox regression analyses were adopted to build a CRC prognostic signature. We further conducted immune feature estimation and chemotherapy analysis between two risk subgroups. Finally, we verified the expression of immune-related prognostic genes at the transcriptional level.

RESULTS

A total of 61 candidate genes were obtained by overlapping key DEGs and key module genes associated with differential immune cells. Then, an immune-related prognostic signature was built based on the three prognostic genes (HAMP, ADAM8, and CD1B). The independent prognostic analysis suggested that age, stage, and RiskScore could be used as independent prognostic factors. Further, we found significantly higher expression of three prognostic genes in the CRC group compared with the normal group. Finally, real-time polymerase chain reaction verified the expression of three genes in patients with CRC.

CONCLUSION

The prognostic signature comprising HAMP, ADAM8, and CD1B based on immune cells was established, providing a theoretical basis and reference value for the research of CRC.

Structural and functional characterisation of HepTH1-5 peptide as a potential hepcidin replacement

Hepcidin is a principal regulator of iron homeostasis and its dysregulation has been recognised as a causative factor in cancers and iron disorders. The strategy of manipulating the presence of hepcidin peptide has been used for cancer treatment. However, this has demonstrated poor efficiency and has been short-lived in patients. Many studies reported using minihepcidin therapy as an alternative way to treat hepcidin dysregulation, but this was only applied to non-cancer patients. Highly conserved fish hepcidin protein, HepTH1-5, was investigated to determine its potential use in developing a hepcidin replacement for human hepcidin (Hepc25) and as a therapeutic agent by targeting the tumour suppressor protein, p53, through structure-function analysis. The authors found that HepTH1-5 is stably bound to ferroportin, compared to Hepc25, by triggering the ferroportin internalisation via Lys42 and Lys270 ubiquitination, in a similar manner to the Hepc25 activity. Moreover, the residues Ile24 and Gly24, along with copper and zinc ligands, interacted with similar residues, Lys24 and Asp1 of Hepc25, respectively, showing that those molecules are crucial to the hepcidin replacement strategy. HepTH1-5 interacts with p53 and activates its function through phosphorylation. This finding shows that HepTH1-5 might be involved in the apoptosis signalling pathway upon a DNA damage response. This study will be very helpful for understanding the mechanism of the hepcidin replacement and providing insights into the HepTH1-5 peptide as a new target for hepcidin and cancer therapeutics.Communicated by Ramaswamy H. Sarma.

Distinctive modulation of hepcidin in cancer and its therapeutic relevance

Hepcidin, a short peptide synthesized primarily by hepatocytes in response to increased body iron and inflammation, is a crucial iron-regulating factor. Hepcidin regulates intestinal iron absorption and releases iron from macrophages into plasma through a negative iron feedback mechanism. The discovery of hepcidin inspired a torrent of research into iron metabolism and related problems, which have radically altered our understanding of human diseases caused by an excess of iron, an iron deficiency, or an iron disparity. It is critical to decipher how tumor cells manage hepcidin expression for their metabolic requirements because iron is necessary for cell survival, particularly for highly active cells like tumor cells. Studies show that tumor and non-tumor cells express and control hepcidin differently. These variations should be explored to produce potential novel cancer treatments. The ability to regulate hepcidin expression to deprive cancer cells of iron may be a new weapon against cancer cells.

Tumoral Overexpression of Hepcidin is Associated with Poor Prognosis of Patients with Clear Cell Renal Cell Carcinoma

This study aimed to investigate the prognostic value of tumoral HAMP expression in patients with clear cell renal cell carcinoma (ccRCC). In a TCGA dataset, we found that HAMP mRNA expression was increased in ccRCC tumors compared with normal controls. Tumoral HAMP mRNA expression was positively correlated with clinical stage, tumor grade, and TNM stages. Patients with high HAMP expression had poorer overall survival than those with low HAMP expression. Tumoral HAMP mRNA level independently predicted the survival of patients. HAMP protein expression was increased in real-world ccRCC tumors compared with those in paired, adjacent noncancerous tissue and was positively correlates with tumor grading. These results suggest HAMP as a potential prognostic factor for ccRCC patients.

The iron-modulating hormone hepcidin is upregulated and associated with poor survival outcomes in renal clear cell carcinoma

Background: Reliable biomarkers are rare for renal cell carcinoma (RCC) treatment selection. We aimed to discover novel biomarkers for precision medicine. The iron-regulating hormone hepcidin (HAMP) was reportedly increased in RCC patient sera and tissues. However, its potential implication as a prognostic biomarker remains exclusive. Methods: Multiple RNA-seq and cDNA microarray datasets were utilized to analyze gene expression profiles. Hepcidin protein expression was assessed using an ELISA assay in cell culture models. Comparisons of gene expression profiles and patient survival outcomes were conducted using the R package bioinformatics software. Results: Five (HAMP, HBS, ISCA2, STEAP2, and STEAP3) out of 71 iron-modulating genes exhibited consistent changes along with tumor stage, lymph node invasion, distal metastasis, tumor cell grade, progression-free interval, overall survival, and disease-specific survival. Of which HAMP upregulation exerted as a superior factor (AUC = 0.911) over the other four genes in distinguishing ccRCC tissue from normal renal tissue. HAMP upregulation was tightly associated with its promoter hypomethylation and immune checkpoint factors (PDCD1, LAG3, TIGIT, and CTLA4). Interleukin-34 (IL34) treatment strongly enhanced hepcidin expression in renal cancer Caki-1 cells. Patients with higher levels of HAMP expression experienced worse survival outcomes. Conclusion: These data suggest that HAMP upregulation is a potent prognostic factor of poor survival outcomes and a novel immunotherapeutic biomarker for ccRCC patients.

Hepcidin Upregulation in Colorectal Cancer Associates with Accumulation of Regulatory Macrophages and Epithelial-Mesenchymal Transition and Correlates with Progression of the Disease

Advanced, metastatic colorectal cancer (CRC) is associated with high rate of mortality because of its poor responsiveness to chemotherapy/immunotherapy. Recent studies have shown that hepcidin, a peptide hormone produced mainly by hepatocytes, is expressed by and enhances the growth of tumor cells. We here assessed whether hepcidin expression helps identify subsets of CRC with advanced and aggressive course. By integrating results of in vitro/ex vivo studies with data of bioinformatics databases, we initially showed that hepcidin RNA and protein expression was more pronounced in tissue samples taken from the tumor area, as compared to the macroscopically unaffected, adjacent, colonic mucosa of CRC patients. The induction of hepcidin in the colonic epithelial cell line HCEC-1ct by interleukin (IL)-6, IL-21 and IL-23 occurred via a Stat3-dependent mechanism and, in primary CRC cells, hepcidin co-localized with active Stat3. In CRC tissue, hepcidin content correlated mainly with macrophage accumulation and IL-10 and CD206 expression, two markers of regulatory macrophages. Consistently, both IL-10 and CD206 were up-regulated by hepcidin in blood mononuclear cells. The highest levels of hepcidin were found in metastatic CRC and survival analysis showed that high expression of hepcidin associated with poor prognosis. Moreover, hepcidin expression correlated with markers of epithelial-to-mesenchymal transition and the silencing of hepcidin in CRC cells reduced epithelial-to-mesenchymal transition markers. These findings indicate that hepcidin is markedly induced in the advanced stages of CRC and suggest that it could serve as a prognostic biomarker in CRC.

Hepcidin as a prognostic biomarker in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common malignancy of urologic neoplasms. Hepcidin is a pivotal modulator of iron metabolism involved in human cancers; however, the biological significance of hepcidin in ccRCC remains to be fully understood. Therefore, in this study, we evaluated the expression profiles of hepcidin in ccRCC from several public databases and found that hepcidin expression was upregulated in ccRCC, which was further validated in ccRCC cell lines, clinical samples, and tissue microarray (TMA) quantitative real-time PCR and immunohistochemistry. In addition, we found that the expression level of hepcidin was correlated with the age, T stage and pathologic stage of patients. Furthermore, hepcidin promoter methylation was significantly associated with the worse poor clinical parameters of ccRCC patients, and hepcidin was an independent prognostic factor. Mechanistically, enrichment analysis revealed that hepcidin participated in the immune-related and metabolism-related pathways. Hepcidin was positively correlated with not only immune infiltration and immune checkpoints but also tumor mutation burden and cytotoxic T lymphocyte. Finally, we validated the positive correlation of hepcidin with the marker of macrophage (CD68) in the TMA. Our findings provide insights into understanding the function and its underlying mechanism of hepcidin in ccRCC and suggest that hepcidin might serve as a potential predictive biomarker of response to immunotherapy and the prognosis of patients with ccRCC.

Identification of a novel mutation gene signature HAMP for cholangiocarcinoma through comprehensive TCGA and GEO data mining

Cholangiocarcinoma (CHOL), the second most common malignant liver tumor, is clinically heterogeneous. In this study, we used gene expression profiles of CHOL obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases to identify novel mutation signatures in CHOL. Hepcidin antimicrobial peptide (HAMP) was identified as a novel diagnostic biomarker for CHOL using the intersection of mutation analysis and receiver operating characteristic (ROC) analysis. We then explored the expression signatures of HAMP in CHOL. HAMP-related differentially expressed genes (DEGs) were selected for the identification of hub genes related to HAMP and for prognostic prediction model analysis. Gene set enrichment analysis (GSEA) showed that the HAMP-related DEGs were mainly enriched for signaling pathways related to cholangiocarcinoma development. Through immunohistochemistry validation, clinical cohorts analysis, and TCGA analysis, we investigated the association between HAMP and clinical parameters and found that decreased HAMP expression was correlated with advanced pathological grade and poor prognosis. Besides, we estimated the immune infiltration level in CHOL and its relationship with HAMP expression. The proportion of tumor-infiltrating cells revealed that gamma delta T cells and monocytes were positively correlated with HAMP expression. Besides, HAMP was also correlated with chemokine, CCL16. This evidence suggested that HAMP might contribute to immune activation in the CHOL microenvironment. Therefore, HAMP may play a synergistic role with these immune cells and chemokines to inhibit CHOL development. HAMP serves as a valuable biomarker in CHOL and is closely correlated with its progression.

Hepcidin Upregulation in Lung Cancer: A Potential Therapeutic Target Associated With Immune Infiltration

Lung cancer has the highest death rate among cancers globally. Hepcidin is a fascinating regulator of iron metabolism; however, the prognostic value of hepcidin and its correlation with immune cell infiltration in lung cancer remain unclear. Here, we comprehensively clarified the prognostic value and potential function of hepcidin in lung cancer. Hepcidin expression was significantly increased in lung cancer. High hepcidin expression was associated with sex, age, metastasis, and pathological stage and significantly predicted an unfavorable prognosis in lung cancer patients. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) results suggested that hepcidin is involved in the immune response. Furthermore, hepcidin expression was positively correlated with the infiltration levels of immune cells and the expression of diverse immune cell marker sets. Importantly, hepcidin may affect prognosis partially by regulating immune infiltration in lung cancer patients. Hepcidin may serve as a candidate prognostic biomarker for determining prognosis associated with immune infiltration in lung cancer.

Iron Dysregulation in Human Cancer: Altered Metabolism, Biomarkers for Diagnosis, Prognosis, Monitoring and Rationale for Therapy

Simple Summary

Iron is the more abundant metal ion in humans. It is essential for life as it has a role in various cellular processes involved, for instance, in cell metabolism and DNA synthesis. These functions are crucial for cell proliferation, and it is therefore not surprising that iron is accumulated in tumors. In this review, we describe normal and altered iron homeostasis mechanisms. We also provide a vision of iron-related proteins with altered expression in cancers and discuss their potential as diagnostic and/or prognostic biomarkers. Finally, we give an overview of therapeutic strategies acting on iron metabolism to fight against cancers.

Abstract

Iron (Fe) is a trace element that plays essential roles in various biological processes such as DNA synthesis and repair, as well as cellular energy production and oxygen transport, and it is currently widely recognized that iron homeostasis is dysregulated in many cancers. Indeed, several iron homeostasis proteins may be responsible for malignant tumor initiation, proliferation, and for the metastatic spread of tumors. A large number of studies demonstrated the potential clinical value of utilizing these deregulated proteins as prognostic and/or predictive biomarkers of malignancy and/or response to anticancer treatments. Additionally, the iron present in cancer cells and the importance of iron in ferroptosis cell death signaling pathways prompted the development of therapeutic strategies against advanced stage or resistant cancers. In this review, we select relevant and promising studies in the field of iron metabolism in cancer research and clinical oncology. Besides this, we discuss some co-existing discrepant findings. We also present and discuss the latest lines of research related to targeting iron, or its regulatory pathways, as potential promising anticancer strategies for human therapy. Iron chelators, such as deferoxamine or iron-oxide-based nanoparticles, which are already tested in clinical trials, alone or in combination with chemotherapy, are also reported.

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.

Different iron-handling in inflamed small and large cholangiocytes and in small and large-duct type intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CCA) represents the second most common primary hepatic malignancy and originates from the neoplastic transformation of the biliary cells. The intrahepatic subtype includes two morpho-molecular forms: large-duct type intrahepatic CCA (iCCA) and small-duct type iCCA. Iron is fundamental for the cellular processes, contributing in tumor development and progression. The aim of this study was to evaluate iron uptake, storage, and efflux proteins in both lipopolysaccharide-inflamed small and large cholangiocytes as well as in different iCCA subtypes. Our results show that, despite an increase in interleukin-6 production by both small and large cholangiocytes, ferroportin (Fpn) was decreased only in small cholangiocytes, whereas transferrin receptor-1 (TfR1) and ferritin (Ftn) did not show any change. Differently from in vitro models, Fpn expression was increased in malignant cholangiocytes of small-duct type iCCA in comparison to large-duct type iCCA and peritumoral tissues. TfR1, Ftn and hepcidin were enhanced, even if at different extent, in both malignant cholangiocytes in comparison to the surrounding samples. Lactoferrin was higher in large-duct type iCCA in respect to small-duct type iCCA and peritumoral tissues. These findings show a different iron handling by inflamed small and large cholangiocytes, and small and large-duct type iCCA. The difference in iron homeostasis by the iCCA subtypes may have implications for the tumor management.

Functional roles of GDF15 in modulating microenvironment to promote carcinogenesis

Obesity and related metabolic dysregulation are risk factors for many types of cancer. The interactions between a developing tumor and its microenvironment are known to implicate a complex "crosstalk" among the factors produced by the population of cells. Among these factors, Growth and differentiation factor 15 (GDF15) has a functional role in cancer. GDF15 expression is induced in response to the conditions associated with cellular stress and diseases. The GDF15 receptor, a member of the glial-cell-derived neurotropic factor family (GDNF), is a GDNF family receptor α-like (GFRAL) protein. GDF15 induces pro-angiogenic effects in tumors. However, GDF15 could affect tumorigenesis both positively and negatively. With a better understanding of the upstream disease pathways reflected by GDF15, new treatment targets may emerge.

The effect of red blood cell transfusion on plasma hepcidin and growth differentiation factor 15 in gastric cancer patients: a prospective study

Background

Hepcidin and growth differentiation factor 15 (GDF-15) have been reported to be highly expressed in various cancers. Serum hepcidin and GDF-15 levels were demonstrated to be potential prognostic markers in cancers. This study aims to evaluate the effect of red blood cell (RBC) transfusion on plasma hepcidin and GDF-15 in gastric cancer patients.

Methods

In this prospective study, 40 patients with gastric cancer were eligible for this study. Peripheral blood samples were obtained before and within 24 h after RBC transfusion. A routine blood test was performed before transfusion and within 24 h post-transfusion. Plasma hepcidin, GDF-15, interleukin 6 (IL-6) and erythropoietin were determined by ELISA.

Results

In patients with metastasis, plasma hepcidin (P=0.02), and GDF-15 (P=0.01) levels were higher than without metastasis. Plasma hepcidin was increased after RBC transfusion (P=0.001), while plasma erythropoietin was decreased after transfusion (P=0.03). However, RBC transfusion did not affect plasma GDF-15 (P=0.32) and IL-6 (P=0.12). The effect of RBC transfusion on variables did not differ between metastatic and non-metastatic patients. The mean percentage change of hepcidin in transfusion volume 4 unit (U) was more than 2 U.

Conclusions

RBC transfusion could increase plasma hepcidin and have no effect on plasma GDF-15 in gastric patients.

A Targeted Mass Spectrometric Assay for Reliable Sensitive Hepcidin Quantification

Hepcidin, a cysteine-rich peptide hormone, secreted mainly by the liver, plays a central role in iron metabolism regulation. Emerging evidence suggests that disordered iron metabolism is a risk factor for various types of diseases including cancers. However, it remains challenging to apply current mass spectrometry (MS)-based hepcidin assays for precise quantification due to the low fragmentation efficiency of intact hepcidin as well as synthesis difficulties for the intact hepcidin standard. To address these issues we recently developed a reliable sensitive targeted MS assay for hepcidin quantification from clinical samples that uses fully alkylated rather than intact hepcidin as the internal standard. Limits of detection and quantification were determined to be <0.5 ng/mL and 1 ng/mL, respectively. Application of the alkylated hepcidin assay to 70 clinical plasma samples (42 non-cancerous and 28 ovarian cancer patient samples) enabled reliable detection of endogenous hepcidin from the plasma samples, as well as conditioned culture media. The hepcidin concentrations ranged from 0.0 to 95.6 ng/mL across non-cancerous and cancer plasma specimens. Interestingly, cancer patients were found to have significantly higher hepcidin concentrations compared to non-cancerous patients (mean: 20.6 ng/ml for cancer; 5.94 ng/ml for non-cancerous) (p value < 0.001). Our results represent the first application of the alkylated hepcidin assay to clinical samples and demonstrate that the developed assay has better sensitivity and quantification accuracy than current MS-based hepcidin assays without the challenges in synthesis of intact hepcidin standard and accurately determining its absolute amount.

Immunonutritional consequences of different serine-type protease inhibitors in a C57BL/6 hepatocarcinoma model

Imbalances in innate immunity and the activity of innate immune cells are implicated in the development of hepatocellular carcinoma (HCC). Plant seeds are good sources of protease inhibitors, which can have a significant influence on human health disorders, especially in the field of cancer prevention. To elucidate the impact and preventive effects of immunonutritional serine-type protease inhibitors (STPIs) on HCC, it was used an established model of chemically induced liver injury. Injured livers induced Akt as well as hepatic infiltration of NKG2D⁺ and CD74⁺ cells. Feeding STPIs reduced size and number of intrahepatic nodes of mononuclear. These animals showed an inverse association of the severity of HCC with bioactive hepcidin levels, which was significantly correlated with the hepatic myeloperoxidase activity. According to their origin, administration of STPIs significantly induce increased numbers of F4/80⁺ cells in injured livers that can be responsible for the biological effects detected on the parenchyma and inflammatory markers under DEN/TAA treatment. These findings can have direct implications in HCC immunotherapy where enhanced response(s) in inflammation-driven cancer patients could help promoting inflammation-driven processes and favor tumor growth. Altogether, this study demonstrates that oral administration of STPIs modulate innate immunity response influencing HCC aggressiveness and progression. These results represent a path forward to develop durable, long-lasting response against hepatocarcinoma and open a future research path in the development of coadjutant intervention strategies to pharmacological therapies.

Serum Hepcidin and GDF-15 levels as prognostic markers in urothelial carcinoma of the upper urinary tract and renal cell carcinoma

Background

Cancer is a life-threatening disease that causes every fourth death. It is often hard to determine the time point of progression. Therefore, biomarkers for cancer entities that indicate disease progression or aggressiveness and thereby guide therapeutic decisions are required. Unfortunately, reliable biomarkers are rare. In this study, the potential of serum hepcidin and serum GDF-15 as biomarkers that correlate with patient’s survival in the two entities upper urinary tract urothelial carcinomas (UUTUC) and renal cell carcinoma (RCC) were analyzed.

Methods

In this retrospective study n = 38 patients suffering from UUTUC, n = 94 patients suffering from RCC and n = 21 patients without infections or cancer, all hospitalized at the University Hospital Muenster, were included. Serum samples of patients were retrospectively analyzed. Serum hepcidin and GDF-15 levels were measured and correlated to aggressiveness and progression of the disease as well as patient’s outcome.

Results

For both entities, UUTUC and RCC, serum hepcidin levels as well as serum GDF-15 levels were increased compared to sera of controls. High serum hepcidin and GDF-15 levels were associated with metastases and cancer relapse. Also, in both entities, the overall survival was decreased in patients with increased serum hepcidin and GDF-15 levels. Hence, high serum hepcidin and GDF-15 levels correlated with patient’s outcome.

Conclusion

To conclude, the data of this study show a correlation of high serum hepcidin and GDF-15 levels with aggressiveness and progression of the disease and demonstrate potential prognostic properties of serum hepcidin and GDF-15 levels. The data support the further assessment of serum hepcidin and GDF-15 as prognostic markers in RCC and UUTUC.

E4BP4 promotes thyroid cancer proliferation by modulating iron homeostasis through repression of hepcidin

Iron homeostasis is critical to mammals, and dysregulation in iron homeostasis usually leads to severe disorders including various cancers. Massive hepcidin secretion is an indicator of thyroid cancer, but the molecular mechanisms responsible for this dysregulation are unknown. Hepcidin secretion from thyroid cancer cells also leads to decreased expression of the iron exporter, ferroportin (FPN), and increased intracellular iron retention, which promote cancer proliferation. In this study, we examined the role of hepcidin in thyroid cancer (TC) and the molecular bases of its signaling. Synthesis of hepcidin is regulated by the BMP4/7 agonist SOSTDC1, which was downregulated in TC; SOSTDC1 downregulation was correlated with G9a-mediated hypermethylation in its promoter. The binding of G9a to the SOSTDC1 promoter requires E4BP4, which interacts with G9a to form a multi-molecular complex that contributes to SOSTDC1 silencing. Silencing of E4BP4 or G9a has similar effects to SOSTDC1 overexpression, which suppresses secretion of hepcidin and inhibits TC cell proliferation. Furthermore, our in vivo xenograft data indicated that depletion of E4BP4 also inhibits cancer growth, reduces hepcidin secretion, and reduces G9a nuclear transportation. Iron homeostasis and tumor growth in TC may be regulated by an E4BP4-dependent epigenetic mechanism. These findings suggest a new mechanism of cellular iron dysfunction through the E4BP4/G9a/SOSTDC1/hepcidin pathway, which is an essential link in TC.

The impact of chemotherapy-associated hemoglobin on prognosis of colorectal cancer patients receiving adjuvant chemotherapy

BACKGROUND AND OBJECTIVE

The association of chemotherapy-associated hemoglobin and survival of colorectal cancer (CRC) receiving adjuvant chemotherapy is uncertain. We sought to explore the prognostic value of chemotherapy-associated hemoglobin in CRC receiving adjuvant chemotherapy and the best cut point affecting prognosis.

METHODS

Three hundred and twenty stage II and III CRC patients receiving adjuvant FOLFOX chemotherapy from March 2003 to March 2012 were enrolled. The associations between chemotherapy-associated hemoglobin (the absolute levels of post-chemotherapy) or chemotherapy-associated hemoglobin change (change between the pre- and post-chemotherapy hemoglobins) and disease free survival (DFS) or overall survival (OS) of CRC, and the best cut point were investigated.

RESULTS

Log rank test showed the best cut points for chemotherapy-associated hemoglobin and chemotherapy-associated hemoglobin change were respectively 90 g/L, 30 g/L. Cox regression model showed chemotherapy-associated hemoglobin < 90 g/L was the independent prognostic factor for DFS (HR, 2.221; 95% CI = 1.157-4.262), OS (HR, 2.058; 95% CI = 1.009-4.197), respectively, but no association of chemotherapy-associated hemoglobin change ⩾ 30g/L and DFS (HR, 2.063; 95% CI = 0.929-4.583), OS (HR, 1.386; 95% CI = 0.553-3.471) was found.

CONCLUSIONS

Chemotherapy-associated hemoglobin < 90 g/L has a significant prognostic value in CRC receiving adjuvant chemotherapy, which is a significant biomarker in the individualized management and may suggest the simple indication for the treatment of anemia in adjuvant chemotherapy in CRC.

Nomograms incorporating genetic variants in BMP/Smad4/Hamp pathway to predict disease outcomes after definitive radiotherapy for non-small cell lung cancer

Hepcidin is crucial in regulating iron metabolism, and increased serum levels were strongly linked with poor outcomes in various malignancies. Thus, we investigated if genetic variants in the BMP/Smad4/Hamp hepcidin-regulating pathway were associated with outcomes in patients receiving definitive radiotherapy for NSCLC. Subjects were 664 NSCLC patients who received ≥60 Gy radiotherapy for NSCLC retrospectively identified from a single-institution database. Potentially, functional and tagging single nucleotide polymorphisms (SNPs) of BMP2 (rs170986, rs1979855, rs1980499, rs235768, and rs3178250), BMP4 (rs17563, rs4898820, and rs762642), Smad4 (rs12456284), and Hamp (rs1882694, rs10402233, rs10421768, and rs12971321) were genotyped by TaqMan real-time polymerase chain reaction. Cox proportional hazard's analyses were used to assess potential influences of SNPs on overall survival (OS), local-regional progression-free survival (LRPFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). Nomogram of each endpoint model was developed using R project. The median patient age was 66 years. Most (488 [73.2%]) had stage III NSCLC. Age, disease stage, receipt of concurrent chemotherapy, and gross tumor volume were independent factors of OS. Hamp rs1882694 AC/CC genotypes were associated with poor OS, LRPFS, PFS, and DMFS in multivariate analyses. Besides, BMP2 rs1979855, rs3178250, and rs1980499 associated with PFS; Hamp rs10402233 and BMP2 rs1979855 associated with LRPFS; BMP2 rs3178250 associated with DMFS after adjustment for clinical factors. After adding SNPs to each model, all the likelihood ratios were increased; the nomograms were improved significantly to predict LRPFS (P < 0.001) and PFS (P < 0.001), and marginally to predict OS (P = 0.056) and DM (P = 0.057). Our nomograms incorporating significant SNPs in the BMP/Smad4/Hamp hepcidin-regulating pathway could improve the prediction of outcomes in patients given definitive radiotherapy for NSCLC. Intensified follow-ups would be recommended for patients with unfavorable outcomes identified in nomograms. Due to the rapid developments of targeted therapies and immunotherapies for NSCLC, it is necessary to further validate our findings in patients receiving such treatments.

Differential regulation of hepcidin in cancer and non-cancer tissues and its clinical implications

Hepcidin is a crucial peptide for regulating cellular iron efflux. Because iron is essential for cell survival, especially for highly active cells, such as tumor cells, it is imperative to understand how tumor cells manipulate hepcidin expression for their own metabolic needs. Studies suggest that hepcidin expression and regulation in tumor cells show important differences in comparison with those in non-tumorous cells. These differences should be investigated to develop new strategies to fight cancer cells. Manipulating hepcidin expression to starve cancer cells for iron may prove to be a new therapy in the anticancer arsenal.

Hepcidin and DNA promoter methylation in hepatocellular carcinoma

BACKGROUND

The liver hormone hepcidin regulates iron homoeostasis that is often altered in hepatocellular carcinoma (HCC). Epigenetic phenomena control gene expression through a dynamic fashion; therefore, considering the plasticity of both iron homoeostasis and epigenetic mechanisms and their role in liver carcinogenesis, we investigated whether hepcidin gene (HAMP) expression is modulated by DNA methylation, thus affecting iron status in human HCC.

MATERIALS AND METHODS

Thirty-two patients affected by nonviral HCC were enrolled, and their main clinical and biochemical characteristics were obtained. Neoplastic and homologous non-neoplastic liver tissues were analysed for HAMP promoter DNA methylation, for HAMP gene expression and for iron content. An in vitro demethylation assay with a human hepatocarcinoma cell line was performed to evaluate the role of DNA methylation on HAMP transcriptional repression.

RESULTS

Gene expression and DNA methylation analyses on tissues showed that HAMP was transcriptionally repressed in HCC tissues consensually with a promoter hypermethylation. Furthermore, patients with HCC had low serum hepcidin concentrations, and HCC tissues had relative iron depletion as compared to non-neoplastic liver tissues. The cell culture model showed the functional role of DNA hypermethylation by downregulating HAMP gene expression. Through a quantitative methylation analysis on HCC tissues, we then proved that methylation at definite CpG sites within consensus sequences for specific transcription factors is possibly the mechanism underlying HAMP repression.

CONCLUSIONS

This study highlights a novel role for HAMP downregulation through DNA promoter hypermethylation and emphasises the significance of epigenetics in the regulation of iron metabolism in HCC.

Increased expression of hepcidin and associated upregulation of JAK/STAT3 signaling in human gastric cancer

Gastric cancer is one of the most common malignancies with high cancer-associated mortality rate globally. Hepcidin is the peptide hormone, which is critically important in the regulation of systemic iron homeostasis. Cumulating evidence has reported that the disturbed local expression of hepcidin may serve as a predictive biomarker in assessing the clinical outcomes in a range of cancer types. However, the expression profile of hepcidin in human gastric cancer is remains to be investigated. In the present retrospective study, using archived paraffin-embedded tissue blocks, the local production of hepcidin by immunohistochemical analysis was detected, and then its correlation with clinicopathological characteristics in human gastric cancer was evaluated. In parallel, using western blotting, quantitative reverse transcription polymerase chain reaction and chromatin immunoprecipitation assay, the local status of Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling in response to inflammatory stimuli mediated by interleukin (IL)-6, which in turn regulates transcriptional activity of hepcidin gene (HAMP) was also assessed. The results indicated that, the local production of hepcidin was significantly elevated in tumor tissues compared with adjacent non-tumor tissues, and was tightly correlated with increasing tumor stages according to the tumor node metastasis (TNM) classification. In addition, JAK/STAT3 signaling and the STAT3 binding affinity to the HAMP gene promoter were significantly enhanced, in parallel with an increased expression of hepcidin, in tumor tissues compared with adjacent non-tumor tissues. Collectively, the present study indicated that local expression of hepcidin in gastric cancer tumor tissues was positively correlated with increasing tumor stages, which may be closely associated with the upregulation of IL-6-mediated JAK/STAT3 signaling in human gastric cancer.

Iron and cancer: recent insights

Iron is an essential dietary element. However, the ability of iron to cycle between oxidized and reduced forms also renders it capable of contributing to free radical formation, which can have deleterious effects, including promutagenic effects that can potentiate tumor formation. Dysregulation of iron metabolism can increase cancer risk and promote tumor growth. Cancer cells exhibit an enhanced dependence on iron relative to their normal counterparts, a phenomenon we have termed iron addiction. Work conducted in the past few years has revealed new cellular processes and mechanisms that deepen our understanding of the link between iron and cancer. Control of iron efflux through the combined action of ferroportin, an iron efflux pump, and its regulator hepcidin appears to play an important role in tumorigenesis. Ferroptosis is a form of iron-dependent cell death involving the production of reactive oxygen species. Specific mechanisms involved in ferroptosis, including depletion of glutathione and inhibition of glutathione peroxidase 4, have been uncovered. Ferritinophagy is a newly identified mechanism for degradation of the iron storage protein ferritin. Perturbations of mechanisms that control transcripts encoding proteins that regulate iron have been observed in cancer cells, including differences in miRNA, methylation, and acetylation. These new insights may ultimately provide new therapeutic opportunities for treating cancer.

Plasma hepcidin in early-stage breast cancer patients: no relationship with interleukin-6, erythropoietin and erythroferrone

OBJECTIVE

Hepcidin-25 production is stimulated by systemic inflammation, and it interferes with iron utilization, leading to anemia. This study aimed to investigate the relationships between the plasma levels of hepcidin, interleukin-6 (IL-6), erythropoietin (EPO) and erythroferrone (ERFE) in patients with benign breast disease or cancer.

METHODS

Plasma samples from a cohort of 131 patients (47 with benign breast disease and 84 with breast cancer) were subjected to the evaluation of hepcidin, IL-6, EPO and ERFE using SELDI-TOF-MS or immunoassays.

RESULTS

An elevated hepcidin was observed in malignant breast tumors compared to benign ones. No correlation was observed between hepcidin and IL-6, EPO or ERFE.

CONCLUSION

Since the study included a cohort of patients (87%) with breast cancers smaller than 2 cm, these results may support our previous evidence about the potential role of hepcidin in breast cancer disease.

Iron metabolism: a double-edged sword in the resistance of glioblastoma to therapies

Glioblastoma (GBM), the deadliest primary tumor of the central nervous system (CNS), is a clear illustration of the resistance of cancer cells to conventional therapies. Application of combinatorial strategies able to overcome pivotal factors of GBM resistance, particularly within the resection margins, represents an essential issue. This review focuses on the role of iron metabolism in GBM progression and resistance to therapy, and the impact of its pharmaceutical modulation on the disease. Iron, through its involvement in many biological processes, is a key factor in the control of cell behavior and cancer biology. Therefore, targeting cellular iron signaling or taking advantage of its dysregulation in cancer cells may lead to new opportunities for improving treatments and drug delivery in GBM.

Serum hepcidin-25 level linked with high mortality in patients with non-Hodgkin lymphoma

Hepatic hepcidin-25 production is stimulated by systemic inflammation, and it interferes with the body's utilization of iron, leading to anemia. A 1-year prospective study was conducted to elucidate an association of serum hepcidin-25 concentration with mortality in anemic patients with non-Hodgkin lymphoma (NHL). Serum hepcidin-25 levels were measured in 50 NHL patients using liquid chromatography-tandem mass spectrometry. The patients were stratified into a high- and a low-hepcidin-25 group according to the median of serum hepcidin-25 concentrations. Factors associated with hemoglobin (Hb) were determined by multivariate regression analysis, incorporating serum hepcidin-25 and inflammatory markers including ferritin and interleukin-6 (IL-6) as covariates. The association between serum hepcidin-25 and mortality was analyzed using both the Kaplan-Meier method and a multivariate proportional hazards regression model. The median of serum hepcidin-25 concentrations was 49.8 (0.6-269) ng/mL, a level approximately nine times greater than the reference value for healthy individuals. Hb level was significantly lower in the high than in the low-hepcidin-25 group. Serum hepcidin-25 was extracted as the significant factor associated with Hb, but neither ferritin nor IL-6 was. The cumulative mortality was significantly greater in the high than in the low-hepcidin-25 group (56.0 vs. 24.0 %; P = 0.0222). The mortality risk for the presence of high hepcidin-25 was four times greater (hazard ratio [95 % confidence interval]: 3.66 [1.12-16.4]). In conclusion, serum hepcidin-25 levels are elevated in anemic NHL patients, and in this study, the group with higher hepcidin-25 levels manifested advanced anemia and poor survival.

Disordered hepcidin-ferroportin signaling promotes breast cancer growth

Iron homeostasis is strictly governed in mammals; however, disordered iron metabolism (such as excess iron burden) is recognized as a risk factor for various types of diseases including cancers. Burgeoning evidence indicates that the central signaling of iron homeostasis, the hepcidin-ferroportin axis, is misregulated in cancers. Nonetheless, the mechanisms of misregulated expression of iron-related genes along this signaling in cancers remain largely unknown. In the current study, we found increased levels of serum hepcidin in breast cancer patients. Reduction of hepatic hepcidin through administration of heparin restrained tumorigenic properties of breast tumor cells. Mechanistic investigation revealed that increased iron, bone morphogenetic protein-6 (BMP6) and interleukin-6 (IL-6) jointly promoted the synthesis of hepatic hepcidin. Tumor hepcidin expression was marginally increased in breast tumors relative to adjacent tissues. In contrast, tumor ferroportin concentration was greatly reduced in breast tumors, especially in malignant tumors, compared to adjacent tissues. Elevation of ferroportin concentration inhibited cell proliferation in vitro and in vivo by knocking down tumor hepcidin expression. Additionally, increased IL-6 was demonstrated to jointly enhance the tumorigenic effects of iron through enforcing cell growth. Our combined data overall deciphered the machinery that altered the hepcidin-ferroportin signaling in breast cancers. Thus, targeting the hepcidin-ferroportin signaling would represent a promising therapeutics to restrain breast cancer growth.

Regulation of cellular iron metabolism and its implications in lung cancer progression

Iron is essential for life and is involved in numerous metabolic processes including cell growth and proliferation. However, excess iron in the body raises the risk of developing cancer due to its capacity to engage in redox cycling and free radical production. Therefore, iron can contribute to both carcinogenesis and tumor growth. Both epidemiologic and laboratory studies have demonstrated that the effects of iron overload are associated with the tumorigenesis of lung cancer and growth of lung cancer cells. In particular, the discovery of hepcidin and several iron transporters in the past decade may warrant reconsideration of the role of iron in carcinogenesis and tumor cell proliferation in lung cancer. Pathways of iron uptake, storage, efflux, and regulation are all disturbed in cancer, suggesting that reprogramming of iron metabolism is a critical aspect of tumor cell survival. Although these pathways in lung cancer have been identified and extensively studied, many issues on the metabolic processes of iron in lung cancer cells have not been addressed. Targeting metabolic pathways of iron may provide new tools for lung cancer prognosis and therapy.

Hepcidin deficiency undermines bone load-bearing capacity through inducing iron overload

Osteoporosis is one of the leading disorders among aged people. Bone loss results from a number of physiological alterations, such as estrogen decline and aging. Meanwhile, iron overload has been recognized as a risk factor for bone loss. Systemic iron homeostasis is fundamentally governed by the hepcidin-ferroportin regulatory axis, where hepcidin is the key regulator. Hepcidin deficiency could induce a few disorders, of which iron overload is the most representative phenotype. However, there was little investigation of the effects of hepcidin deficiency on bone metabolism. To this end, hepcidin-deficient (Hamp1(-/-)) mice were employed to address this issue. Our results revealed that significant iron overload was induced in Hamp1(-/-) mice. Importantly, significant decreases of maximal loading and maximal bending stress were found in Hamp1(-/-) mice relative to wildtype (WT) mice. Moreover, the levels of the C-telopeptide of type I collagen (CTX-1) increased in Hamp1(-/-) mice. Therefore, hepcidin deficiency resulted in a marked reduction of bone load-bearing capacity likely through enhancing bone resorption, suggesting a direct correlation between hepcidin deficiency and bone loss. Targeting hepcidin or the pathway it modulates may thus represent a therapeutic for osteopenia or osteoporosis.

Increased hepcidin expression in non-small cell lung cancer tissue and serum is associated with clinical stage

BACKGROUND

Hepcidin is a small secreted peptide that plays a key role in iron metabolism. A high level of hepcidin expression may be implicated in colorectal cancer; however, the relationship between hepcidin and lung cancer has not yet been studied.

METHODS

Serum hepcidin-25, bone morphogenetic protein (BMP)-2, and interleukin (IL)-6 concentration in 53 patients and 16 non-cancerous individuals was measured by enzyme-linked immune sorbent assay. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was utilized to study the expression of hepcidin mRNA in paired tumor and non-tumor lung tissues in surgical specimens from 65 patients with non small cell lung cancer (NSCLC), as well as in six types of lung cancer cell lines and human bronchial epithelial (HBE) cells. Hepcidin protein expression and cellular localization in NSCLC was determined by immunohistochemistry.

RESULTS

The serum hepcidin-25 concentration was higher in patients with NSCLC than in non-cancerous individuals, and was positively correlated with serum BMP2 concentration, but negatively with serum IL-6 levels. Serum hepcidin was also correlated with lymph node metastasis and clinical stage. Hepcidin mRNA expression was higher in cancerous tissues of NSCLC than in normal pulmonary tissues (P = 0.001). Hepcidin mRNA levels in four lung carcinoma cell lines were higher than in HBE cells. Immunohistochemistry showed that hepcidin protein was increased in cancerous tissues of NSCLC.

CONCLUSIONS

The level of hepcidin expression increased in NSCLC tissue and serum. Serum hepcidin-25 level was associated with lymph node metastasis and tumor clinical stage in patients with NSCLC.

Hepcidin in neoplastic disease

Abnormalities in iron metabolism are frequent in the neoplastic disease. The relationship between hepcidin and iron homeostasis in cancerous pathology is incompletely known, although it has been studied during the last years. This paper aims to analyze the role of hepcidin in the neoplastic processes, its correlation with carcinogenesis and anemia, and with the disease activity. It must be mentioned that most of the aspects presented need to be verified in practice. Insufficient data are known for showing hepcidin involvement in carcinogenesis, metastasis or in appreciating the response to anemia treatment in neoplasia.

Hemochromatosis enhances tumor progression via upregulation of intracellular iron in head and neck cancer

Introduction

Despite improvements in treatment strategies for head and neck squamous cell carcinoma (HNSCC), outcomes have not significantly improved; highlighting the importance of identifying novel therapeutic approaches to target this disease. To address this challenge, we proceeded to evaluate the role of iron in HNSCC.

Experimental Design

Expression levels of iron-related genes were evaluated in HNSCC cell lines using quantitative RT-PCR. Cellular phenotypic effects were assessed using viability (MTS), clonogenic survival, BrdU, and tumor formation assays. The prognostic significance of iron-related proteins was determined using immunohistochemistry.

Results

In a panel of HNSCC cell lines, hemochromatosis (HFE) was one of the most overexpressed genes involved in iron regulation. In vitro knockdown of HFE in HNSCC cell lines significantly decreased hepcidin (HAMP) expression and intracellular iron level. This in turn, resulted in a significant decrease in HNSCC cell viability, clonogenicity, DNA synthesis, and Wnt signalling. These cellular changes were reversed by re-introducing iron back into HNSCC cells after HFE knockdown, indicating that iron was mediating this phenotype. Concordantly, treating HNSCC cells with an iron chelator, ciclopirox olamine (CPX), significantly reduced viability and clonogenic survival. Finally, patients with high HFE expression experienced a reduced survival compared to patients with low HFE expression.

Conclusions

Our data identify HFE as potentially novel prognostic marker in HNSCC that promotes tumour progression via HAMP and elevated intracellular iron levels, leading to increased cellular proliferation and tumour formation. Hence, these findings suggest that iron chelators might have a therapeutic role in HNSCC management.

Novel chelators for cancer treatment: where are we now?

SIGNIFICANCE

Under normal circumstances, cellular iron levels are tightly regulated due to the potential toxic effects of this metal ion. There is evidence that tumors possess altered iron homeostasis, which is mediated by the perturbed expression of iron-related proteins, for example, transferrin receptor 1, ferritin and ferroportin 1. The de-regulation of iron homeostasis in cancer cells reveals a particular vulnerability to iron-depletion using iron chelators. In this review, we examine the absorption of iron from the gut; its transport, metabolism, and homeostasis in mammals; and the molecular pathways involved. Additionally, evidence for alterations in iron processing in cancer are described along with the perturbations in other biologically important transition metal ions, for example, copper(II) and zinc(II). These changes can be therapeutically manipulated by the use of novel chelators that have recently been shown to be highly effective in terms of inhibiting tumor growth.

RECENT ADVANCES

Such chelators include those of the thiosemicarbazone class that were originally thought to target only ribonucleotide reductase, but are now known to have multiple effects, including the generation of cytotoxic radicals.

CRITICAL ISSUES

Several chelators have shown marked anti-tumor activity in vivo against a variety of solid tumors. An important aspect is the toxicology and the efficacy of these agents in clinical trials.

FUTURE DIRECTIONS

As part of the process of the clinical assessment of the new chelators, an extensive toxicological assessment in multiple animal models is essential for designing appropriate dosing protocols in humans.

On the origin of cancer metastasis

Metastasis involves the spread of cancer cells from the primary tumor to surrounding tissues and to distant organs and is the primary cause of cancer morbidity and mortality. In order to complete the metastatic cascade, cancer cells must detach from the primary tumor, intravasate into the circulatory and lymphatic systems, evade immune attack, extravasate at distant capillary beds, and invade and proliferate in distant organs. Currently, several hypotheses have been advanced to explain the origin of cancer metastasis. These involve an epithelial mesenchymal transition, an accumulation of mutations in stem cells, a macrophage facilitation process, and a macrophage origin involving either transformation or fusion hybridization with neoplastic cells. Many of the properties of metastatic cancer cells are also seen in normal macrophages. A macrophage origin of metastasis can also explain the long-standing "seed and soil" hypothesis and the absence of metastasis in plant cancers. The view of metastasis as a macrophage metabolic disease can provide novel insight for therapeutic management.

Mass spectrometry of peptides and proteins from human blood

It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post-translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post-translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ∼1 ng/mL.

Basic research in kidney cancer

CONTEXT

Advances in basic research will enhance prognosis, diagnosis, and treatment of renal cancer patients.

OBJECTIVE

To discuss advances in our understanding of the molecular basis of renal cancer, targeted therapies, renal cancer and immunity, and genetic factors and renal cell carcinoma (RCC).

EVIDENCE ACQUISITION

Data on recently published (2005-2011) basic science papers were reviewed.

EVIDENCE SYNTHESIS

Advances in basic research have shown that renal cancers can be subdivided based on specific genetic profiles. Now that this molecular basis has been established, it is becoming clear that additional events play a major role in the development of renal cancer. For example, aberrant chromatin remodelling appears to be a main driving force behind tumour progression in clear cell RCC. A large number of potential biomarkers have emerged using various high-throughput platforms, but adequate biomarkers for RCC are still lacking. To bring the potential biomarkers and biomarker profiles to the clinical arena is a major challenge for the field. The introduction of tyrosine kinase inhibitors (TKIs) for therapy has shifted the interest away from immunologic approaches. Nevertheless, a wealth of evidence supports immunotherapy for RCC. Interestingly, studies are now appearing that suggest a combination of TKI and immunotherapy may be beneficial. Thus far, little attention has been paid to patient-specific differences. With high-throughput methods becoming cheaper and with the advances in sequencing possibilities, this situation is expected to change rapidly.

CONCLUSIONS

Great strides have been made in the understanding of molecular mechanisms of RCC. This has led this field to the enviable position of having a range of molecularly targeted therapies. Large sequencing efforts are now revealing more and more genes responsible for tumour development and progression, offering new targets for therapy. It is foreseen that through integration of high-throughput platforms, personalised cancer treatment for RCC patients will become possible.

Serum prohepcidin levels in children with solid tumors, inflammatory bowel disease and iron deficiency anemia

BACKGROUND

Prohepcidin is one of the regulators of iron metabolism. Few studies examined its relation with solid tumors (ST), inflammatory bowel disease (IBD) and iron deficiency anemia (IDA) in children.

METHODS

We measured serum prohepcidin (SP), soluble transferrin receptor (sTfR), serum ferritin (SF), serum iron (SI), transferrin saturation (TS), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels in ST (n = 16), IBD (n = 15), IDA (n = 14) and controls (n = 18).

RESULTS

The mean SP was significantly higher in ST and IBD than in IDA and controls. SP was significantly correlated with SF in ST, IBD and ESR for IBD and CRP for ST and hemoglobin for ST.

CONCLUSION

Elevated SP may be a clinically important predictor of inflammation and leads to anemia by impairing iron utilization in IBD and ST. SP decreases in IDA and is correlated with TS but not with SF or sTfR.

Serum interferon alpha receptor 2 mRNA may predict efficacy of interferon alpha with/without low-dose sorafenib for metastatic clear cell renal cell carcinoma

Background

Interferon (IFN) alpha is one of the central agents in immunotherapy for renal cell carcinoma (RCC). It acts by binding to the IFN-alpha receptor (IFNAR). We previously reported that increased tumor expression of IFNAR2 mRNA was associated with the metastatic potential and progression of RCC, as well as with a poor response of metastatic RCC to IFN-alpha therapy. This study investigated the influence of serum IFNAR2 in RCC patients.

Methods

We measured serum IFNAR2 mRNA levels and quantified IFNAR mRNA expression in paired tumor and non-tumor tissues from the surgical specimens of 66 consecutive RCC patients by the real-time reverse transcription polymerase chain reaction (RT-PCR). We also measured phosphorylated Akt (Ser-473) and phosphorylated-S6 ribosomal protein (Ser-235/236) proteins levels in paired tumor and non-tumor tissues of patients with metastatic RCC by Western blotting.

Results

The serum level of IFNAR2 mRNA was not associated with its tumor tissue level. Serum IFNAR2 mRNA was positively correlated with tumor size (P < 0.05), but not with tumor grade, pT stage, metastasis, microscopic vascular invasion, or serum C-reactive protein. Serum levels of IFNAR2 mRNA were significantly higher in patients with a good response to IFN-alpha ± sorafenib than in those with a poor response (P < 0.0001). Tumor tissue IFNAR2 mRNA levels and phosphorylated-S6 ribosomal protein (Ser-235/236) levels were associated with metastatic potential (P < 0.001 and P < 0.01, respectively), and patients with a low IFNAR2 mRNA level and low phosphorylated Akt (Ser-473) protein level in the primary tumor showed a good response to IFN-α ± sorafenib (IFN-α ± Sor: CR-PR) (P < 0.01 and P < 0.05, respectively). Kaplan–Meier survival analysis showed that a higher serum IFNAR2 mRNA level was associated with longer overall survival of treated patients (P < 0.05), while a higher tumor tissue IFNAR2 mRNA level was related to shorter overall survival (P < 0.01).

Conclusions

Our findings suggest that a high serum level of IFNAR2 mRNA may be a useful marker for predicting the response of metastatic RCC to IFN-alpha ± sorafenib therapy.

Tilapia (Oreochromis mossambicus) antimicrobial peptide, hepcidin 1-5, shows antitumor activity in cancer cells

The inhibitory function of tilapia hepcidin (TH)1-5, an antimicrobial peptide, was not examined in previous studies. In this study, we synthesized the TH1-5 peptide and tested TH1-5's antitumor activity against several tumor cell lines. We show that TH1-5 inhibited the proliferation of tumor cells and reduced colony formation in a soft agar assay. Scanning electron microscopy and transmission electron microscopy showed that TH1-5 altered the membrane structure similar to the function of a lytic peptide. Acridine orange/ethidium bromide staining, a wound-healing assay, and a flow cytometric analysis showed that TH1-5 induced necrosis with high-concentration treatment and induced apoptosis with low-concentration treatment. Inflammation is known to be closely associated with the development of cancer. TH1-5 showing anti-inflammatory effects in a previous publication induced us to evaluate the anti-inflammatory effects in cancer cell lines through the expressions of immune-related genes after being treated with the TH1-5 peptide. However, real-time qualitative RT-PCR indicated that TH1-5 treatment induced downregulation of the expressions of interleukin (IL)-6, IL-8, IL-12, IL-15, interferon-γ, CTSG, caspase-7, and Bcl-2, and upregulation of IL-2 and CAPN5 in HeLa cells, and upregulation of IL-8 and CTSG in HT1080 cells. These results suggest that TH1-5 possibly induces an inflammatory response in HeLa cells, but not in HT1080 cells. Overall, these results indicate that TH1-5 possesses the potential to be a novel peptide for cancer therapy.

C-reactive protein is a strong predictor for anaemia in renal cell carcinoma: role of IL-6 in overall survival

OBJECTIVE

• To elucidate the association of progression of advanced renal cell carcinoma with anaemia and investigate factors influencing tumor-associated anaemia.

PATIENTS AND METHODS

• We analyzed different clinical variables to study associations with anaemia in 86 metastatic renal cell carcinoma patients. • 45 (52%) of patients had already developed anaemia prior to therapy.

RESULTS

• Anaemic patients had an increase in the serum markers C-reactive protein (CRP), IL-6 and erythropoietin (EPO). In addition we observed substantial correlation between IL-6 and CRP serum levels (R = 0.639, P < 0.0001). • Univariate logistic regression analysis revealed that patients with IL-6 >10 pg/mL had a considerable increase in risk for anaemia (odds ratio 3.86, P= 0.003). • In addition, patients with CRP >0.7 mg/dL had a very strong increase in risk for anaemia (OR = 14.08, P < 0.0001). • Stepwise multivariate logistic regression analysis confirmed CRP >0.7 mg/mL as the only independent predictor for anaemia. Cox-regression modeling selected serum IL-6 as the strongest independent prognostic indicator (hazard ratio 3.58, P < 0.0001).

CONCLUSION

• Anaemia depends on serum IL-6, which is a strong inductor of CRP and regulator of the iron-transport. Serum IL-6 may be considered as a target to treat cancer-related anaemia.

Chi-square comparison of tryptic peptide-to-protein distributions of tandem mass spectrometry from blood with those of random expectation

Proteomics uses tandem mass spectrometers and correlation algorithms to match peptides and their fragment spectra to amino acid sequences. The replication of multiple liquid chromatography experiments with electrospray ionization of peptides and tandem mass spectrometry (LC-ESI-MS/MS) produces large sets of MS/MS spectra. There is a need to assess the quality of large sets of experimental results by statistical comparison with that of random expectation. Classical frequency-based statistics such as goodness-of-fit tests for peptide-to-protein distributions could be used to calculate the probability that an entire set of experimental results has arisen by random chance. The frequency distributions of authentic MS/MS spectra from human blood were compared with those of false positive MS/MS spectra generated by a computer, or instrument noise, using the chi-square test. Here the mechanics of the chi-square test to compare the results in toto from a set of LC-ESI-MS/MS experiments with those of random expectation is detailed. The chi-square analysis of authentic spectra demonstrates unambiguously that the analysis of blood proteins separated by partition chromatography prior to tryptic digestions has a low probability that the cumulative peptide-to-protein distribution is the same as that of random or noise false positive spectra.