Successful Control of Disseminated Intravascular Coagulation by Recombinant Thrombomodulin during Arsenic Trioxide Treatment in Relapsed Patient with Acute Promyelocytic Leukemia

Disseminated intravascular coagulation (DIC) frequently occurs in patients with acute promyelocytic leukemia (APL). With the induction of therapy in APL using all-trans retinoic acid (ATRA), DIC can be controlled in most cases as ATRA usually shows immediate improvement of the APL. However, arsenic trioxide (ATO) which has been used for the treatment of relapse in APL patients has shown to take time to suppress APL cells, therefore the control of DIC in APL with ATO treatment is a major problem. Recently, the recombinant soluble thrombomodulin fragment has received a lot of attention as the novel drug for the treatment of DIC with high efficacy. Here, we present a relapsed patient with APL in whom DIC was successfully and safely controlled by rTM during treatment with ATO

Iron facilitator LS081 reduces hypoxia-inducible factor-1α protein and functions as anticancer agent in hepatocellular carcinoma.

AuthorHypoxia inducible factor-1α (HIF-1α) has a central role in cellular oxygen-sensing, and its overexpression in many types of cancer is considered important in tumor progression. Thus, targeting HIF-1α production and activity has been of great therapeutic interest. In normoxic conditions, HIF-1α is hydroxylated by oxygen-dependent prolyl-hydroxylases, which require ferrous iron for its activity. The tumor suppressor protein von Hippel Lindau binds to the hydroxylated HIF-1α, which is then ubiquitinated and degraded by proteasomes. We focused on the physiological degradation machinery of HIF-1α mediated by prolyl hydroxylases. Previously, we identified a small molecule, LS081, that is capable of stimulating iron uptake into cells. In the present study, we aimed to inhibit the expression of HIF-1α protein and growth of hepatocellular carcinoma by using the iron-facilitating activity of LS081. In the human hepatocellular carcinoma cell lines Hep3B and HepG2, a combination of LS081 and ferric ammonium citrate (LS081/FeAC) inhibited HIF-1α protein expression but did not inhibit HIF-1α mRNA expression. A mutated HIF-1α protein, which has proline residues that were replaced with alanine and transfected into HEK293 cells, was not affected by the combination of LS081 and FeAC. Furthermore, the iron-facilitating activity of LS081 resulted in Hep3B and HepG2 growth inhibition in vitro and in vivo. These results indicate that the iron-facilitating activity of LS081 inhibits HIF-1α expression through prolyl-hydroxylation of HIF-1α and might have a therapeutic effect in the treatment of hepatocellular carcinoma

The three isoforms of hepcidin in human serum and their processing determined by liquid chromatography-tandem mass spectrometry (LC-tandem MS)

The final publication is available at Springer via http://dx.doi.org/10.1007/s12185-015-1885-yHepcidin, the iron regulatory hormone, has three isoforms; -20, -22 and -25. While hepcidin-25 has been studied extensively, the physiological significance of other isoforms remains poorly understood. Using a quantitative method based on liquid chromatography-tandem mass spectrometry (LC-tandem MS) developed by our group, we quantified hepcidin isoforms in human serum to elucidate their characteristics, and investigated the role of hepatocytes in isoform processing. Hepcidin isoforms in serum obtained from 40 healthy volunteers were quantified. Synthetic hepcidin peptides were added to healthy serum, and to HepG2 culture media, and hepcidin isoform concentrations determined. All three hepcidin isoforms were detected in human serum; however, hepcidin-25 concentrations were highest. The three hepcidin isoforms showed a strong positive correlation with each other and with serum ferritin. Additionally, while hepcidin-20 was strongly correlated with serum creatinine, the other isoforms were not. Hepcidin-20 and -25 levels were also increased in chronic kidney disease (CKD) serum. Hepcidin-22 rapidly degraded into hepcidin-20, whereas hepcidin-25 remained relatively stable. Finally, hepcidin-22 degradation into hepcidin-20 was accelerated in the presence of HepG2. This method has enabled us to reveal fundamental characteristics of the three hepcidin isoforms in serum and may be a powerful tool for quantifying hepcidin isoform expression and processing

In vivo behavior of NTBI revealed by automated quantification system.

The final publication is available at Springer via http://dx.doi.org/10.1007/s12185-016-2002-6.Non-Tf-bound iron (NTBI), which appears in serum in iron overload, is thought to contribute to organ damage; the monitoring of serum NTBI levels may therefore be clinically useful in iron-overloaded patients. However, NTBI quantification methods remain complex, limiting their use in clinical practice. To overcome the technical difficulties often encountered, we recently developed a novel automated NTBI quantification system capable of measuring large numbers of samples. In the present study, we investigated the in vivo behavior of NTBI in human and animal serum using this newly established automated system. Average NTBI in healthy volunteers was 0.44 ± 0.076 μM (median 0.45 μM, range 0.28-0.66 μM), with no significant difference between sexes. Additionally, serum NTBI rapidly increased after iron loading, followed by a sudden disappearance. NTBI levels also decreased in inflammation. The results indicate that NTBI is a unique marker of iron metabolism, unlike other markers of iron metabolism, such as serum ferritin. Our new automated NTBI quantification method may help to reveal the clinical significance of NTBI and contribute to our understanding of iron overload

Non-transferrin-bound iron assay system utilizing a conventional automated analyzer.

authorIron is an essential metal in the body, but its excessive accumulation causes damage in various organs through free radical production. Iron homeostasis is therefore tightly regulated. However, when iron balance collapses, such as in prolonged transfusion, transferrin (Tf) is fully saturated and non-Tf-bound iron (NTBI) appears in the serum. Monitoring serum NTBI levels is therefore crucial in assessment of the clinical status of patients with iron overload, since NTBI is associated with cellular and organ damage. Several methods for NTBI determination have been reported, but these are extremely complicated and very few laboratories can quantify NTBI at present. In this study, we established a novel assay system utilizing automated analyzers that are widely used in clinical laboratories for diagnostic testing. In this assay, NTBI is chelated by nitrilotriacetic acid (NTA), after which the iron is reduced and transferred to nitroso-PSAP, a chromogen. The assay shows excellent linearity, reproducibility, and compatibility with HPLC, one of the most reliable conventional methods for NTBI quantification. Our novel method for NTBI measurement is high-throughput and may be a useful and powerful tool in study of the physiological and clinical importance of NTBI

Iron-induced epigenetic abnormalities of mouse bone marrow through aberrant activation of aconitase and isocitrate dehydrogenase

The final publication is available at Springer via http://dx.doi.org/10.1007/s12185-016-2054-7Iron overload remains a concern in myelodysplastic syndrome (MDS) patients. Iron chelation therapy (ICT) thus plays an integral role in the management of these patients. Moreover, ICT has been shown to prolong leukemia-free survival in MDS patients; however, the mechanisms responsible for this effect are unclear. Iron is a key molecule for regulating cytosolic aconitase 1 (ACO1). Additionally, the mutation of isocitrate dehydrogenase (IDH), the enzyme downstream of ACO1 in the TCA cycle, is associated with epigenetic abnormalities secondary to 2-hydroxyglutarate (2-HG) and DNA methylation. However, epigenetic abnormalities observed in many MDS patients occur without IDH mutation. We hypothesized that iron itself activates the ACO1-IDH pathway, which may increase 2-HG and DNA methylation, and eventually contribute to leukemogenesis without IDH mutation. Using whole RNA sequencing of bone marrow cells in iron-overloaded mice, we observed that the enzymes, phosphoglucomutase 1, glycogen debranching enzyme, and isocitrate dehydrogenase 1 (Idh1), which are involved in glycogen and glucose metabolism, were increased. Digital PCR further showed that Idh1 and Aco1, enzymes involved in the TCA cycle, were also elevated. Additionally, enzymatic activities of TCA cycle and methylated DNA were increased. Iron chelation reversed these phenomena. In conclusion, iron activation of glucose metabolism causes an increase of 2-HG and DNA methylation

Iron overload patients with unknown etiology from national survey in Japan

Transfusion is believed to be the main cause of iron overload in Japan. A nationwide survey on post-transfusional iron overload subsequently led to the establishment of guidelines for iron chelation therapy in this country. To date, however, detailed clinical information on the entire iron overload population in Japan has not been fully investigated. In the present study, we obtained and studied detailed clinical information on the iron overload patient population in Japan. Of 1109 iron overload cases, 93.1% were considered to have occurred post-transfusion. There were, however, 76 cases of iron overload of unknown origin, which suggest that many clinicians in Japan may encounter some difficulty in correctly diagnosing and treating iron overload. Further clinical data were obtained for 32 cases of iron overload of unknown origin; median of serum ferritin was 1860.5 ng/mL. As occurs in post-transfusional iron overload, liver dysfunction was found to be as high as 95.7% when serum ferritin levels exceeded 1000 ng/mL in these patients. Gene mutation analysis of the iron metabolism-related genes in 27 cases of iron overload with unknown etiology revealed mutations in the gene coding hemojuvelin, transferrin receptor 2, and ferroportin; this indicates that although rare, hereditary hemochromatosis does occur in Japan