Extracellular volume fraction using contrast-enhanced CT is useful in differentiating intrahepatic cholangiocellular carcinoma from hepatocellular carcinoma

Objectives

To evaluate whether tumor extracellular volume fraction (fECV) on contrast-enhanced computed tomography (CT) aids in the differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC).

Methods

In this retrospective study, 113 patients with pathologically confirmed ICC (n = 39) or HCC (n = 74) who had undergone preoperative contrast-enhanced CT were enrolled. Enhancement values of the tumor (Etumor) and aorta (Eaorta) were obtained in the precontrast and equilibrium phase CT images. fECV was calculated using the following equation: fECV [%] = Etumor/Eaorta × (100 - hematocrit [%]). fECV values were compared between the ICC and HCC groups using Welch's t-test. The diagnostic performance of fECV for differentiating ICC and HCC was assessed using receiver-operating characteristic (ROC) analysis. fECV and the CT imaging features of tumors were evaluated by two radiologists. Multivariate logistic regression analysis was performed to identify factors predicting a diagnosis of ICC.

Results

Mean fECV was significantly higher in ICCs (43.8% ± 13.2%) than that in HCCs (31.6% ± 9.0%, p < 0.001). The area under the curve for differentiating ICC from HCC was 0.763 when the cutoff value of fECV was 41.5%. The multivariate analysis identified fECV (unit OR: 1.10; 95% CI: 1.01-1.21; p < 0.05), peripheral rim enhancement during the arterial phase (OR: 17.0; 95% CI: 1.29-225; p < 0.05), and absence of washout pattern (OR: 235; 95% CI: 14.03-3933; p < 0.001) as independent CT features for differentiating between the two tumor types.

Conclusions

A high value of fECV, peripheral rim enhancement during the arterial phase, and absence of washout pattern were independent factors in the differentiation of ICC from HCC.

Kinetics of Anti-SARS-CoV-2 Antibody Response Following Two Doses of the BNT162b2 mRNA Vaccine: A Japanese Single-Center Primary Care Clinic Report Involving Volunteers and Patients with Autoimmune Disease

Despite the promising effectiveness of the coronavirus disease 2019 vaccination using an mRNA vaccine, the short efficacy duration and some poor responses to the vaccination remain major concerns. We aimed to clarify the monthly kinetics of the anti-SARS-CoV-2 spike receptor-binding domain antibody response after two doses of the BNT162b2 vaccine in a Japanese population. A chemiluminescent enzyme immunoassay (CLIA) and an enzyme-linked immunosorbent assay were used to measure the antibody levels in 81 Japanese adults (age, <65 years). The antibody levels increased 10-fold at 2−3 weeks following the second dose of BNT162b2 and declined thereafter to approximately 50%, 20%, and 10% of the peak levels at 2, 3, and 6 months, respectively. To compare the antibody titers among different groups, older adults (age, >65 years; n = 38) and patients with systemic lupus erythematosus (SLE, n = 14) were also investigated. A decline in the mean relative antibody titers was observed in older men compared with younger men and in patients with SLE compared with individuals aged <65 years. Although the antibody levels increased drastically following two BNT162b2 doses, they then declined rapidly. Furthermore, poor responders to the vaccination were observed. Repeated vaccinations are required to maintain high antibody levels.

Multicenter prospective trial of total gastrectomy versus proximal gastrectomy for upper third cT1 gastric cancer

BACKGROUND

The appropriate surgical procedure for patients with upper third early gastric cancer is controversial. We compared total gastrectomy (TG) with proximal gastrectomy (PG) in this patient population.

METHODS

A multicenter, non-randomized trial was conducted, with patients treated with PG or TG. We compared short- and long-term outcomes between these procedures.

RESULTS

Between 2009 and 2014, we enrolled 254 patients from 22 institutions; data from 252 were included in the analysis. These 252 patients were assigned to either the PG (n = 159) or TG (n = 93) group. Percentage of body weight loss (%BWL) at 1 year after surgery, i.e., the primary endpoint, in the PG group was significantly less than that of the TG group (- 12.8% versus - 16.9%; p = 0.0001). For short-term outcomes, operation time was significantly shorter for PG than TG (252 min versus 303 min; p < 0.0001), but there were no group-dependent differences in blood loss and postoperative complications. For long-term outcomes, incidence of reflux esophagitis in the PG group was significantly higher than that of the TG group (14.5% versus 5.4%; p = 0.02), while there were no differences in the incidence of anastomotic stenosis between the two (5.7% versus 5.4%; p = 0.92). Overall patient survival rates were similar between the two groups (3-year survival rates: 96% versus 92% in the PG and TG groups, respectively; p = 0.49).

CONCLUSIONS

Patients who underwent PG were better able to control weight loss without worsening the prognosis, relative to those in the TG group. Optimization of a reconstruction method to reduce reflux in PG patients will be important.

Insulinoma induces a hyperinsulinemia-mediated decrease of GLUT2 and GLP1 receptor in normal pancreatic β-cells

There have been several clinical reports of transient postoperative hyperglycemia in patients with insulinoma, but the effect of insulinoma on normal β-cells has not been investigated. We examined the glucose transporter 2 (GLUT2) and glucagon-like peptide 1 receptor (GLP1R) expression in normal pancreatic β-cells of five patients with insulinoma and five patients with normal glucose tolerance (NGT) as controls. The positive rate of GLUT2-or GLP1R-positive islets in the nontumor area was calculated by the ratio with the analyzed islets. For functional in vitro analyses, q-PCR and Western blotting were performed after insulin loading on MIN6 cells. The expression rates of both GLUT2 and GLP1R were significantly lower in nontumor area islets of insulinoma patients than in patients with NGT (GLUT2: 31.6 ± 15.3% vs 95.9 ± 6.7%, p < 0.01, GLP1R: 66.8 ± 15.0% vs 96.7 ± 5.0%, p < 0.01). Exposure of MIN6 cells to high concentrations of insulin resulted in a significant decrease in GLUT2 protein for 12 h and GLP1R protein for 24 h (GLUT2; 1.00 ± 0.079 vs 0.81 ± 0.04. p = 0.02, GLP1R; 1.00 ± 0.10 vs 0.50 ± 0.24, p = 0.03) but not in those mRNAs. Our findings show that insulinoma is associated with the downregulation of GLUT2 and GLP1R expression in nontumor area islets. These phenomena may be caused by high levels of insulin.

Impact of high-dose statin on cardiovascular outcomes in real-world patients with ST-elevation acute myocardial infarction

Little is known about the impact of a high-dose statin on cardiovascular outcomes after ST-elevation acute myocardial infarction (STEMI) in real-world Japanese patients. Between July 2011 and June 2017, 1110 consecutive STEMI patients underwent primary percutaneous coronary intervention at our hospital and were discharged. A high-dose statin was administered in 117 patients (10.5%) and non-high-dose statin was administered in 947 patients (85.3%). The low-density lipoprotein cholesterol level was significantly higher in the high-dose statin group at admission (129.8 ± 44.9 vs. 110.4 ± 32.7, p < 0.0001), but the levels were not significantly different at follow-up (86.7 ± 25.7 vs. 85.0 ± 25.0, p = 0.52). The cumulative 2-year incidence of a composite of cardiac death, myocardial infarction, ischemic stroke, and any unplanned coronary revascularization was significantly lower in the high-dose statin group (6.2% vs. 16.9%, log-rank p = 0.004). Propensity score matched analysis indicated similar results. Among the types of coronary revascularization, a high-dose statin was significantly correlated with a lower rate of de novo lesion revascularization (hazard ratio 0.31; 95% confidence interval 0.08-0.83; p = 0.02). The results of our analyses indicate that administration of a high-dose statin may result in better cardiovascular outcomes after STEMI mainly by reducing the rate of revascularization for de novo lesions regardless of the achieved low-density lipoprotein cholesterol level in real-world patients.

Liver resection with thrombectomy for patients with hepatocellular carcinoma and tumour thrombus in the inferior vena cava or right atrium

Background

Hepatocellular carcinoma (HCC) with tumour thrombus (TT) in the inferior vena cava (IVC) or right atrium (RA) is a rare advanced disease state with a poor prognosis. The aim of this study was to examine survival after surgical resection.

Methods

Patients with HCC and TT of either the IVC or RA, who underwent liver resection between February 1997 and July 2017, were included. Their short‐ and long‐term outcomes and surgical details were analysed retrospectively.

Results

Thirty‐seven patients were included; 16 patients had TT in the IVC below the diaphragm, eight had TT in the IVC above the diaphragm, and 13 had TT entering the RA. Twelve patients had advanced portal vein TT (portal vein invasion (Vp) greater than Vp3 and Vp4), ten had bilobar disease, and 12 had extrahepatic disease. There were no in‐hospital deaths, although two patients died within 90 days. Median survival did not differ between patients who had resection with curative intent (18·7 months) and those with residual tumour in the lung only (20·7 months), but survival was poor for patients with residual tumour in the liver (8·3 months).

Conclusion

Liver resection with thrombectomy for advanced HCC with TT in the IVC or RA is safe and feasible, leading to moderate survival.

Catalytic enhancement on Ti–Zr complex oxide particles for electrochemical hydrogenation of oxalic acid to produce an alcoholic compound by controlling electronic states and oxide structures

Ti_0.9Zr_0.1O₂ complex oxide particles exhibit superior catalytic performances for the direct power storage into glycolic acid via electroreduction of oxalic acid due to favorable crystallinity.

Work-related psychosocial factors and metabolic syndrome onset among workers: a systematic review and meta-analysis

BACKGROUND

Work-related psychosocial factors have been associated with metabolic syndrome. However, no systematic reviews or meta-analyses have evaluated this association.

METHODS

A systematic literature search was conducted, using PubMed, Embase, PsycINFO, PsycARTICLES and the Japan Medical Abstracts Society. Eligible studies included those that examined the previously mentioned association; had a longitudinal or prospective cohort design; were conducted among workers; provided sufficient data for calculating odds ratios, relative risks or hazard ratios with 95% confidence intervals; were original articles in English or Japanese; and were published no later than 2016. Study characteristics, exposure and outcome variables and association measures of studies were extracted by the investigators independently.

RESULTS

Among 4,664 identified studies, 8 were eligible for review and meta-analysis. The pooled risk of adverse work-related stress on metabolic syndrome onset was significant and positive (RR = 1.47; 95% CI, 1.22-1.78). Sensitivity analyses limiting only the effects of job strain and shift work also indicated a significant positive relationship (RR = 1.75; 95% CI, 1.09-2.79; and RR = 1.59; 95% CI, 1.00-2.54, P = 0.049 respectively).

CONCLUSION

This study reveals a strong positive association between work-related psychosocial factors and an elevated risk of metabolic syndrome onset. The effects of job strain and shift work on metabolic syndrome appear to be significant.

Simultaneous hyperthermia-chemotherapy effect by arterial injection of Fe(Salen) for femur tumor

We previously identified a novel nanomagnetic particle, N,N′‐bis(salicylidene)ethylenediamine iron [Fe(Salen)]. Fe(Salen) not only shows antitumor effects but also magnetic properties. We found that Fe(Salen) can be used for magnet‐guided drug delivery and visualization of accumulated drug by magnetic resonance imaging (MRI) because of its magnetism. In addition, Fe(Salen) can generate heat by itself when exposed to an alternating current magnetic field (AMF), resulting in a hyperthermia effect. Herein, we partly elucidated the antitumor mechanism of Fe(Salen) and carried out an i.v. repeated dose toxicity study to decide the therapeutic amount. Furthermore, we evaluated the antitumor effect of selective intra‐arterial injection or i.v. injection of Fe(Salen) by catheter and the hyperthermia effect of Fe(Salen) when exposed to AMF in vivo. We used a rabbit model grafted with VX2 cells (rabbit squamous cell carcinoma) on the right leg. Intra‐arterial injection of Fe(Salen) showed a greater antitumor effect than did i.v. injection. The combination of Fe(Salen) intra‐arterial injection and AMF exposure showed a greater antitumor effect than did either Fe(Salen) or methotrexate (MTX) without AMF exposure, suggesting that AMF exposure greatly enhanced the antitumor effect of Fe(Salen) by arterial injection by catheter. This is the first report that the effectiveness of Fe(Salen) was evaluated in the point of administration route; that is, selective intra‐arterial injection by catheter. Taken together, these results indicate a new administration route; that is, selective arterial injection of Fe(Salen) by catheter, and the development of a new strategy of simultaneous hyperthermia‐chemotherapy in the future.

Alternating magnetic field enhances cytotoxicity of Compound C

We previously reported the efficacy of anti-cancer therapy with hyperthermia using an alternating magnetic field (AMF) and a magnetic compound. In the course of the study, unexpectedly, we found that an AMF enhances the cytotoxicity of Compound C, an activated protein kinase (AMPK) inhibitor, although this compound is not magnetic. Therefore, we examined the cellular mechanism of AMF-induced cytotoxicity of Compound C in cultured human glioblastoma (GB) cells. An AMF (280 kHz, 250 Arms) for 30 minutes significantly enhanced the cytotoxicity of Compound C and promoted apoptosis towards several human GB cell lines in vitro. The AMF also increased Compound C-induced cell-cycle arrest of GB cells at the G2 phase and, thus, inhibited cell proliferation. The AMF increased Compound C-induced reactive oxygen species production. Furthermore, the AMF decreased ERK phosphorylation in the presence of Compound C and suppressed the protective autophagy induced by this compound. The application of an AMF in cancer chemotherapy may be a simple and promising method, which might reduce the doses of drugs used in future cancer treatment and, therefore, the associated side effects.

Diagnostic test accuracy of antigenaemia assay for PCR-proven cytomegalovirus infection-systematic review and meta-analysis

OBJECTIVES

We aimed to assess diagnostic test accuracy of antigenaemia assay for PCR-proven cytomegalovirus (CMV) infection.

METHODS

We systematically searched studies that provide data both on sensitivity and specificity of the CMV antigenaemia assay using the PCR as the reference standard. Adults, children, infants, individuals who were immunocompromised for any reason, symptomatic patients and asymptomatic individuals were all included. A hierarchical summary receiver operating characteristics model was used for diagnostic meta-analysis. Study quality was assessed by Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies. Protocol registration identification is CRD42016035892.

RESULTS

We identified 75 eligible articles including 9058 CMV PCR-positive individuals and 22 232 PCR-negative individuals. The diagnostic odds ratio for positive antigenaemia was 30 (95% CI 24-38, I² = 28%) and the area under the hierarchical summary receiver operating characteristic curve was 0.86 (95% CI 0.83-0.88). The summary estimates of sensitivity and specificity were 0.65 (95% CI 0.59-0.70) and 0.94 (95% CI 0.93-0.95), respectively. The positive likelihood ratio of 10.9 (95% CI 8.5-14.0) suggested that a positive result from the antigenaemia assay greatly increased the probability of PCR-proven CMV infection, but a negative likelihood ratio of 0.38 (95% CI 0.32-0.44) indicated that a negative result led to a small decrease in the probability of PCR-proven CMV infection. Sensitivity and subgroup analyses replicated these results.

CONCLUSIONS

The antigenaemia assay overlooked 35% of PCR-proven CMV infections; hence, a negative result of an antigenaemia assay could not rule out a CMV infection.

HLA-G1, but Not HLA-G3, Suppresses Human Monocyte/Macrophage-mediated Swine Endothelial Cell Lysis

The inhibitory function of HLA-G1, a class Ib molecule, on monocyte/macrophage-mediated cytotoxicity was examined. The expression of inhibitory receptors that interact with HLA-G, immunoglobulin-like transcript 2 (ILT2), ILT4, and KIR2DL4 (CD158d) on in vitro-generated macrophages obtained from peripheral blood mononuclear cells and the phorbol 12-myristate 13-acetate (PMA)-activated THP-1 cells were examined by flow cytometry. cDNAs of HLA-G1, HLA-G3, HLA-E, and human β2-microglobulin were prepared, transfected into pig endothelial cells (PECs), and macrophage- and the THP-1 cell-mediated PEC cytolysis was then assessed. In vitro-generated macrophages expressed not only ILT2 and ILT4 but CD158d as well. The transgenic HLA-G1 on PEC indicated a significant suppression in macrophage-mediated cytotoxicity, which was equivalent to that of transgenic HLA-E. HLA-G1 was clearly expressed on the cell surface of PEC, whereas the levels of HLA-G3 were much lower and remained in the intracellular space. On the other hand, the PMA-activated THP-1 cell was less expressed these inhibitory molecules than in vitro-generated macrophages. Therefore, the HLA-G1 on PECs showed a significant but relatively smaller suppression to THP-1 cell-mediated cytotoxicity compared to in vitro-generated macrophages. These results indicate that by generating HLA-G1, but not HLA-G3, transgenic pigs can protect porcine grafts from monocyte/macrophage-mediated cytotoxicity.

Studies of Pig Complement: Measurement of Pig CH50, ACH50, and Components

BACKGROUND

On the basis of a comparison of the hemolytic complement titer in pigs with that in humans, the complement system of pigs was investigated. The response of innate immunity, such as the natural antibodies, against humans was also examined.

METHODS

Hemolytic complement activity of pig serum was measured with the use of a microtitration technique. CH50 was determined according to the method of Mayer. ACH50 was assayed according to the methods of Platts-Milles and Ishizaka. Hemolytic activities of C1, C4, C2, C3, C5, C8, and C9 were estimated through the use of intermediate cells and reagents, as described previously. In addition, the pig natural anti-human antibody was studied with the use of human peripheral blood mononuclear cells (PBMCs). Human PBMCs were stained with 5% pig serum, followed by staining with fluorescein isothiocyanate-labeled goat anti-pig IgG and IgM. The resulting stained cells were quantified by use of a FACScalibur system. The alternative pathway of pig complement was also measured with the use of human erythrocytes and normal pooled pig serum with or without Mg(++)EGTA.

RESULTS

Both the CH50 and ACH50 titers were lower than those of humans. Concerning the components, except for C3, each component, that is, C1, C4, C2, C5, C8, and C9, was also lower than that of humans, based on measured values for human complement components. Pig serum clearly contains natural antibodies, IgG and IgM, to human PBMCs. The alternative pathway of pig complement reacted with human erythrocytes.

CONCLUSIONS

As a whole, pig innate immunity, the complement system and natural antibody, recognizes the surfaces of human cells.

Knockout of Cytidine Monophospho-N-Acetylneuraminic Acid (CMP-NeuAc) Hydroxylase From Porcine Endothelial Cells by a CRISPR System

BACKGROUND

We attempted to knock out the expression of Hanganutziu-Deicher (H-D) antigens through the use of a CRISPR (clustered regulatory interspaced short palindromic repeat)/Cas9 system for pig cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH).

METHODS

Plasmids expressing hCas9 and sgRNA for pCMAH were prepared by ligating oligos into the BbsI site of pX330. The N-terminal and C-terminal EGFP coding regions overlapping 482 bp were PCR-amplified and placed under a ubiquitous CAG promoter. The approximately 400-bp genomic fragments containing the sgRNA target sequence of pCMAH were placed into the multi-cloning sites flanked by the EGFP fragments. The pCAG-EGxxFP-target was mixed with pX330 with/without the sgRNA sequences and then introduced into HEK293T cells.

RESULTS

Four oligos and primers, gSO1, gSO3, gSO4, and gSO8, were nominated from 8 candidates. Among them, gSO1 showed the best efficiency. Pig endothelial cells (PECs) from an α-Gal knockout pig were then used to examine the changes in the expression of the H-D antigen by the knockout of the CMAH genome by the pX330-gS01.

CONCLUSIONS

Changes in the expression of the H-D antigen in the PECs with the CRISPR (gS01) were clear in comparison with those in the parental cells, on the basis of FACS analysis data. The expression of the H-D antigen can be knocked out by use of the CRISPR system for pCMAH, thus confirming that this system is a very convenient system for producing knockout pigs.

Supplemental Analysis for N-linked Sugars in Adult Pig Islets

The pig pancreas is considered to be one of the most suitable sources of islets for clinical xenotransplantation. However, after producing α1-3galactosyltransferase knockout pigs, most of the organs of these pigs showed less antigenicity to the human body. Wild-type adult pig islets (APIs) that originally produced negligible levels of α-Gal, different from neonatal porcine islet-like cell clusters, showed a clear antigenicity to human serum. Concerning the so-called non-Gal epitopes, many studies related to glycoproteins and glycolipids are ongoing in efforts to identify them. However, our knowledge of non-Gal glycoantigens remains incomplete. In our previous study, N-glycans were isolated from APIs, and the structures of 28 of the N-glycans were detected. In this study, to identify additional structures, further analyses were performed by liquid chromatography-mass spectrometry (LC-MS). N-glycans were isolated from APIs by the method described by O'Neil et al with minor modifications and LC-MS-based structural analyses were then performed. The detected N-glycan peaks in the LC-MS spectra were selected using the FLexAnalysis software program and the structures of the glycans were predicted using the GlyocoMod Tool. The API preparation contained 11 peaks and 16 structures were then nominated as containing N-linked sugars. Among them, 5 sulfated glycans were estimated, confirming the existence of sulfate structures in N-glycans in API. In addition, these data may supplement several N-glycan structures that contain two deoxyhexose units, such as fucose, to our previous report. The data herein will be helpful for future studies of antigenicity associated with API.

Human HLA-Ev (147) Expression in Transgenic Animals

BACKGROUND

In our previous study, we reported on the development of substituting S147C for HLA-E as a useful gene tool for xenotransplantation. In this study we exchanged the codon of HLA-Ev (147), checked its function, and established a line of transgenic mice.

METHODS

A new construct, a codon exchanging human HLA-Ev (147) + IRES + human beta 2-microgloblin, was established. The construct was subcloned into pCXN2 (the chick beta-actin promoter and cytomegalovirus enhancer) vector. Natural killer cell- and macrophage-mediated cytotoxicities were performed using the established the pig endothelial cell (PEC) line with the new gene. Transgenic mice with it were next produced using a micro-injection method.

RESULTS

The expression of the molecule on PECs was confirmed by the transfection of the plasmid. The established molecules on PECs functioned well in regulating natural killer cell-mediated cytotoxicity and macrophage-mediated cytotoxicity. We have also successfully generated several lines of transgenic mice with this plasmid. The expression of HLA-Ev (147) in each mouse organ was confirmed by assessing the mRNA. The chick beta-actin promoter and cytomegalovirus enhancer resulted in a relatively broad expression of the gene in each organ, and a strong expression in the cases of the heart and lung.

CONCLUSION

A synthetic HLA-Ev (147) gene with a codon usage optimized to a mammalian system represents a critical factor in the development of transgenic animals for xenotransplantation.

Simultaneous hyperthermia-chemotherapy with controlled drug delivery using single-drug nanoparticles

We previously investigated the utility of μ-oxo N,N'- bis(salicylidene)ethylenediamine iron (Fe(Salen)) nanoparticles as a new anti-cancer agent for magnet-guided delivery with anti-cancer activity. Fe(Salen) nanoparticles should rapidly heat up in an alternating magnetic field (AMF), and we hypothesized that these single-drug nanoparticles would be effective for combined hyperthermia-chemotherapy. Conventional hyperthermic particles are usually made of iron oxide, and thus cannot exhibit anti-cancer activity in the absence of an AMF. We found that Fe(Salen) nanoparticles induced apoptosis in cultured cancer cells, and that AMF exposure enhanced the apoptotic effect. Therefore, we evaluated the combined three-fold strategy, i.e., chemotherapy with Fe(Salen) nanoparticles, magnetically guided delivery of the nanoparticles to the tumor, and AMF-induced heating of the nanoparticles to induce local hyperthermia, in a rabbit model of tongue cancer. Intravenous administration of Fe(Salen) nanoparticles per se inhibited tumor growth before the other two modalities were applied. This inhibition was enhanced when a magnet was used to accumulate Fe(Salen) nanoparticles at the tongue. When an AMF was further applied (magnet-guided chemotherapy plus hyperthermia), the tumor masses were dramatically reduced. These results indicate that our strategy of combined hyperthermia-chemotherapy using Fe(Salen) nanoparticles specifically delivered with magnetic guidance represents a powerful new approach for cancer treatment.

Abstract 4548: Simultaneous hyperthermic-chemotherapy for glioblastoma using a single anti-cancer compound with intrinsic magnetism

Background: Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumor in humans. In spite of advances in treatment strategies, survival rate of GBM remains poor. We have recently reported a novel anti-cancer compound with intrinsic magnetism(EI236). In addition to its anti-cancer effect, EI236 generates a large amount of heat upon an alternating magnetic field (AMF) application because of its magnetism, i.e., hyperthermic effect. In this study, we have examined the effect of EI236 on human GBM in vitroand vivo.

Materials and Methods: Human GBM cell lines, U251MG, YKG-1, and U87, were used in this study. Cell proliferation was assessed by methyl thiazolyl tetrazorium (MTT) assays in the presence of EI236, in comparison to temozolomide (TMZ) and calmustine (BCNU), i.e. the clinical standard drugs for GBM. Apoptosis was analyzed by fluorescence activated cells sorting. In addition, we have examined whether EI236 inhibited the tumor growth with/without AMF application in animal models. Tumors were induced by implantation of U251MG cells into the hip of female Balb-c mice. Seven days after the implantation of GBM cells, EI236, BCNU or normal saline (control) was injected respectively into the tumors and mice were exposed to an AMF application(330.8A, 280kHz) for 30 minutes. Therefore, we calculated the tumor volume and the regression rate of tumors twice a week.

Result: EI236 inhibited the proliferation of all cell lines and increased apoptosis in a dose dependent manner. Moreover, we found that EI236 had much greater anti-cancer effect than the clinical standard drugs. Mice bearing GBM cancer cells in their hip were then subjected to a double combination therapy, consisting of local injection of EI236 and hyperthermic treatment by AMF application. Tumor sizes in both drug stimulation groups were reduced, especially that in EI236 with AMF application group was highly reduced, while that in control group was increased.

Conclusion: EI236 has greater anti-cancer effect than TMZ and BCNU, i.e. the clinical standard drugs. Besides this strong anti-cancer effect, EI236 has hyperthermic effect upon an AMF application because of heat generation. Accordingly, EI236 may enable us to develop novel strategies in GBM treatment, i.e. hyperthermic-chemotherapy with a single-drug compound.

Note: This abstract was not presented at the meeting.

Citation Format: Makoto Ohtake, Masanari Umemura, Itaru Sato, Kayoko Oda, Akane Nagasako, Ayako Makino, Haruki Aoyama, Mayumi Katsumata, Haruki Eguchi, Nobutaka Kawahara, Yoshihiro Ishikawa. Simultaneous hyperthermic-chemotherapy for glioblastoma using a single anti-cancer compound with intrinsic magnetism. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4548. doi:10.1158/1538-7445.AM2015-4548

Abstract 4398: Methotrexate derivative with intrinsic magnetism

Background: We previously reported the generation of a novel paclitaxel derivative with intrinsic magnetism. Similarly, we have synthesized a novel derivative of methotrexate, a conventional drug for cancer and rheumatic diseases, with intrinsic magnetism (M-MTX). MTX is widely used in clinical treatments, however various severe side effects such as renal, hepatic, and pulmonary toxicities or bone marrow suppression have been reported. This is a single methotrexate compound with intrinsic magnetism and is not a methotrexate encapsulated in micelle with magnetic particles. The magnetic property contributes to unique features. 1) It can be attracted by a magnet, resulting in reduction of the side effects. 2) It can be visualized by magnetic resonance imaging (MRI), suggesting that we can identify the localization of drug and quantify the amount of this drug. In this study, we have examined whether M-MTX has both the magnetic and the anti-cancer property with similar efficacy to commercial available methotrexate.

Materials & Methods: The magnetic property of M-MTX was measured by Electron Spin Resonance (ESR) and Superconducting Quantum Interference Device (SQUID). MCF7, breast cancer cells were obtained from RIKEN Bioresource center in this study. Cell proliferation was assessed by a commercially available kit, XTT Cell Proliferation Assay Kit (ATCC). Apoptotic cells were stained with APC Annexin V and 7-AAD, and measured by fluorescence activated cell sorting (FACS), to evaluate early and late apoptosis. The intracellular ROS level was then measured using a fluorescent dye, 2′,7′-dichlorofluorescein diacetate (DCFH-DA; Sigma, Japan)

Results: M-MTX was easily attracted by a neodium magnet. Plots of magnetization versus magnetic field revealed that the magnetized methotrexate exhibits spontaneous magnetization in SQUID. ESR also showed that M-MTX has an intrinsic magnetism. Furthermore, M-MTX inhibited cell proliferation and induced cellular apoptosis in MCF7 cell lines in a dose-dependent manner. M-MTX also increased reactive oxygen species (ROS) generation, suggesting that M-MTX might retained the original anti-cancer property.

Conclusion: M-MTX may provide us a new strategy for cancer therapy, i.e., chemotherapy with magnetic drug delivery with a single agent. These results also suggested that various conventional anti-cancer drugs might be similarly magnetized, leading to novel drug developments in future cancer chemotherapy and other treatments.

Note: This abstract was not presented at the meeting.

Citation Format: MASANARI UMEMURA, Mayumi Katsumata, Itaru Sato, Akane Nagasako, Haruki Aoyama, Ayako Makino, Makoto Ohtake, Kayoko Oda, Kosuke Matsuo, Haruki Eguchi, Yoshihiro Ishikawa. Methotrexate derivative with intrinsic magnetism. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4398. doi:10.1158/1538-7445.AM2015-4398

Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer

Background:

Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC).

Methods:

Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT–PCR.

Results:

Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).

Conclusions:

Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.

A magnetic anti-cancer compound for magnet-guided delivery and magnetic resonance imaging

Research on controlled drug delivery for cancer chemotherapy has focused mainly on ways to deliver existing anti-cancer drug compounds to specified targets, e.g., by conjugating them with magnetic particles or encapsulating them in micelles. Here, we show that an iron-salen, i.e., μ-oxo N,N'- bis(salicylidene)ethylenediamine iron (Fe(Salen)), but not other metal salen derivatives, intrinsically exhibits both magnetic character and anti-cancer activity. X-Ray crystallographic analysis and first principles calculations based on the measured structure support this. It promoted apoptosis of various cancer cell lines, likely, via production of reactive oxygen species. In mouse leg tumor and tail melanoma models, Fe(Salen) delivery with magnet caused a robust decrease in tumor size, and the accumulation of Fe(Salen) was visualized by magnetic resonance imaging. Fe(Salen) is an anti-cancer compound with magnetic property, which is suitable for drug delivery and imaging. We believe such magnetic anti-cancer drugs have the potential to greatly advance cancer chemotherapy for new theranostics and drug-delivery strategies.

Identification of a bona fide microRNA biomarker in serum exosomes that predicts hepatocellular carcinoma recurrence after liver transplantation

Background

Predictive biomarkers for the recurrence of hepatocellular carcinoma (HCC) have great benefit in the selection of treatment options, including liver transplantation (LT), for HCC. The purpose of this study was to identify specific microRNAs (miRs) in exosomes from the serum of patients with recurrent HCC and to validate these molecules as novel biomarkers for HCC recurrence.

Methods

We employed microarray-based expression profiling of miRs derived from exosomes in the serum of HCC patients to identify a biomarker that distinguishes between patients with and without HCC recurrence after LT. This was followed by the validation in a separate cohort of 59 HCC patients who underwent living related LT. The functions and potential gene targets of the recurrence-specific miRs were analysed using a database, clinical samples and HCC cell lines.

Results

We found that miR-718 showed significantly different expression in the serum exosomes of HCC cases with recurrence after LT compared with those without recurrence. Decreased expression of miR-718 was associated with HCC tumour aggressiveness in the validated cohort series. We identified HOXB8 as a potential target gene of miR-718, and its upregulation was associated with poor prognosis.

Conclusion

Circulating miRs in serum exosomes have potential as novel biomarkers for predicting HCC recurrence.

Monocytic suppressor cells derived from peripheral blood suppress xenogenic natural killer cell lysis

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) were initially found to contribute to immunosuppression in tumor patients and have recently been recognized as a subset of innate immune cells that are capable of regulating adaptive immunity. A variety of innate immune stimuli, such as lipopolysaccharide, act as a double-edged sword, inducing both the maturation of dendritic cells and the expansion of MDSCs.

METHODS

We isolated MDSCs from peripheral blood mononuclear cells (PBMCs) and examined the suppressive effect of MDSCs against xenocytotoxicity mediated by YT cells, a natural killer-like cell line, with the use of the lactate dehydrogenase assay method.

RESULTS

Although primed MDSCs induced no significant suppression in YT cell-mediated cytotoxicity, activated MDSCs significantly suppressed the xenogenic cytotoxicity.

CONCLUSIONS

These findings indicate that MDSCs have a great deal of potential as a therapeutic strategy for dealing with xenograft rejection. Further investigations of the underlying mechanisms will facilitate the development of this therapeutic strategy.

MicroRNA-1246 expression associated with CCNG2-mediated chemoresistance and stemness in pancreatic cancer

Background:

Pancreatic cancer has a poor prognosis because of its high refractoriness to chemotherapy and tumour recurrence, and these properties have been attributed to cancer stem cells (CSCs). MicroRNA (miRNA) regulates various molecular mechanisms of cancer progression associated with CSCs. This study aimed to identify the candidate miRNA and to characterise the clinical significance.

Methods:

We established gemcitabine-resistant Panc1 cells, and induced CSC-like properties through sphere formation. Candidate miRNAs were selected through microarray analysis. The overexpression and knockdown experiments were performed by evaluating the in vitro cell growth and in vivo tumourigenicity. The expression was studied in 24 pancreatic cancer samples after laser captured microdissection and by immunohistochemical staining.

Results:

The in vitro drug sensitivity of pancreatic cancer cells was altered according to the miR-1246 expression via CCNG2. In vivo, we found that miR-1246 could increase tumour-initiating potential and induced drug resistance. A high expression level of miR-1246 was correlated with a worse prognosis and CCNG2 expression was significantly lower in those patients.

Conclusions:

miR-1246 expression was associated with chemoresistance and CSC-like properties via CCNG2, and could predict worse prognosis in pancreatic cancer patients.

Hyperthermia generated with ferucarbotran (Resovist®) in an alternating magnetic field enhances cisplatin-induced apoptosis of cultured human oral cancer cells

Hyperthermia is a promising anti-cancer treatment in which the tissue temperature is increased to 42-45 °C, and which is often used in combination with chemotherapy or radiation therapy. Our aim in the present work was to examine the feasibility of combination therapy for oral cancer with cisplatin and hyperthermia generated with ferucarbotran (Resovist(®); superparamagnetic iron oxide) in an alternating magnetic field (AMF). First, we established that administration of ferucarbotran at the approved dosage for magnetic resonance imaging provides an iron concentration sufficient to increase the temperature to 42.5 °C upon exposure to AMF. Then, we examined the effect of cisplatin combined with ferucarbotran/AMF-induced hyperthermia on cultured human oral cancer cells (HSC-3 and OSC-19). Cisplatin alone induced apoptosis of cancer cells in a dose-dependent manner, as is well known. However, the combination of cisplatin with ferucarbotran/AMF was significantly more effective than cisplatin alone. This result suggests that it might be possible to reduce the clinically effective dosage of cisplatin by administering it in combination with ferucarbotran/AMF-induced hyperthermia, thereby potentially reducing the incidence of serious cisplatin-related side effects. Further work seems justified to evaluate simultaneous thermo-chemotherapy as a new approach to anticancer therapy.

Amplification of PVT-1 is involved in poor prognosis via apoptosis inhibition in colorectal cancers

Background:

We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear.

Methods:

We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT–PCR.

Results:

CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-β signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients.

Conclusion:

PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.

Association between tissue characteristics evaluated with optical coherence tomography and mid-term results after paclitaxel-coated balloon dilatation for in-stent restenosis lesions: a comparison with plain old balloon angioplasty

AIMS

Morphological assessment of neointimal tissue using optical coherence tomography (OCT) is important for clarifying the pathophysiology of in-stent restenosis (ISR) lesions. The aim of this study was to determine the impact of OCT findings on recurrence of ISR after paclitaxel-coated balloon (PCB) dilatation compared with plain old balloon angioplasty (POBA).

METHODS AND RESULTS

Between July 2008 and May 2012, we performed percutaneous coronary intervention for 214 ISR lesions using POBA + PCB (146 lesions, PCB group) or POBA only (68 lesions, POBA group). Morphological assessment of neointimal tissue using OCT, including assessment of restenotic tissue structure and restenotic tissue backscatter, was performed. We examined the association between lesion morphologies and mid-term (6-8 months) results including ISR and target lesion revascularization (TLR) rates. Both ISR and TLR rates of lesions with a homogeneous structure were significantly lower in the PCB group than those in the POBA group (ISR: 20.0 vs. 55.6%, P = 0.002, TLR: 12.7 vs. 37.0%, P = 0.019), but there was no difference between the two groups in ISR and TLR rates of lesions with a heterogeneous or layered structure. Both ISR and TLR rates of lesions with high backscatter were significantly lower in the PCB group than those in the POBA group (ISR: 19.8 vs. 52.5%, P < 0.001, TLR: 13.6 vs. 42.5%, P = 0.001), but there was no difference between the two groups in ISR and TLR rates of lesions with low backscatter.

CONCLUSION

Morphological assessment of ISR tissue using OCT might be useful for identifying ISR lesions favourable for PCB dilatation.

miR-320c regulates gemcitabine-resistance in pancreatic cancer via SMARCC1

Background:

Gemcitabine-based chemotherapy is the standard treatment for pancreatic cancer. However, the issue of resistance remains unresolved. The aim of this study was to identify microRNAs (miRNAs) that govern the resistance to gemcitabine in pancreatic cancer.

Methods:

miRNA microarray analysis using gemcitabine-resistant clones of MiaPaCa2 (MiaPaCa2-RGs), PSN1 (PSN1-RGs), and their parental cells (MiaPaCa2-P, PSN1-P) was conducted. Changes in the anti-cancer effects of gemcitabine were studied after gain/loss-of-function analysis of the candidate miRNA. Further assessment of the putative target gene was performed in vitro and in 66 pancreatic cancer clinical samples.

Results:

miR-320c expression was significantly higher in MiaPaCa2-RGs and PSN1-RGs than in their parental cells. miR-320c induced resistance to gemcitabine in MiaPaCa2. Further experiments showed that miR-320c-related resistance to gemcitabine was mediated through SMARCC1, a core subunit of the switch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex. In addition, clinical examination revealed that only SMARCC1-positive patients benefited from gemcitabine therapy with regard to survival after recurrence (P=0.0463).

Conclusion:

The results indicate that miR-320c regulates the resistance of pancreatic cancer cells to gemcitabine through SMARCC1, suggesting that miR-320c/SMARCC1 could be suitable for prediction of the clinical response and potential therapeutic target in pancreatic cancer patients on gemcitabine-based therapy.

Predominance of β-cell neogenesis rather than replication in humans with an impaired glucose tolerance and newly diagnosed diabetes

CONTEXT

A decrease in pancreatic β-cell mass is involved in the development of type 2 diabetes.

OBJECTIVE

The purpose of this study was to evaluate the β-cell mass and the incidence of β-cell neogenesis, replication, and apoptosis at both the prediabetic and diabetic stages.

METHODS

We conducted a cross-sectional study of pancreatic tissues obtained from 42 patients undergoing a pancreatectomy who were classified into 4 groups: normal glucose tolerance (n = 11), impaired glucose tolerance (n = 11), newly diagnosed diabetes (n = 10), and long-standing type 2 diabetes (n = 10).

RESULTS

The relative β-cell area decreased and the β-cell apoptosis increased during the development of diabetes. The number of single and clustered β-cells, some of which coexpressed nestin, increased in the patients with impaired glucose tolerance and newly diagnosed diabetes. The prevalence of cells positive for both insulin and glucagon or somatostatin also increased in these patients compared with those with normal glucose tolerance. These double-positive cells were mainly localized in single and clustered β-cells, rather than large islets, and were also positive for Pdx1 or Ngn3. The percentage of insulin-positive cells embedded within ducts increased in the impaired glucose tolerance group. There were no significant differences in the incidence of cells positive for both insulin and Ki67 among the groups.

CONCLUSIONS

These results suggest that β-cell neogenesis, rather than replication, predominates during impaired glucose tolerance and newly diagnosed diabetes in humans and may serve as a compensatory mechanism for the decreased β-cell mass.

Abstract 5568: Thermochemotherapy with controlled drug delivery using a novel magnetic anti-cancer drug

Background:

Radical surgery for patients with oral cancer may cause dysfunction, such as dysphagia, dysarthria, or mastication disorders, leading to decreased quality of life in cancer patients. Here, we report the development of a novel magnetic anti-cancer drug, EI236, which may enable us to reduce such problems. EI236 possesses three features; anti-cancer effect alike cisplatin, controlled drug delivery using a magnet, and hyperthermic effect upon exposure to an alternating current magnetic field (ACMF). We thus examined the efficacy of EI236 in treating oral cancer in a rabbit cancer model.

Methods:

Cell proliferation was measured by MTT assays. We established the rabbit tongue cancer model using VX2 cells, which are readily transplantable in vivo. Electromagnet was used to attract EI236 to the site of tongue cancer by controlled drug delivery (CDR), and ACMF to generate heat from EI236 (HT). Rabbits were divided into 4 groups: control group, intravenous EI236 injection group (5mg/kg×7days) (i.v.), intravenous EI236 injection + electromagnet group (i.v. + CDR), intravenous EI236 injection + electromagnet + ACMF group (i.v. + CDR + HT). The size of tumors was measured daily for 7 days, followed by histopathological evaluation. Of note, EI236 was injected at the same dose in the three groups.

Results:

EI236 showed anti-cancer effects in a dose-dependent manner in VX2 cells. The IC50 value of EI236 was 7.5μM in cultured cells. The resultant tumor volume after EI236 i.v. injection treatment in rabbits was as follows; 319.3±40.0% for control, 228.5±94.3% for i.v., 91.5±27.4X% for i.v. + CDR, 24±8.2% for i.v. + CDR + HT, indicating that the i.v. + CDR + HT group showed the greatest decrease. It also showed the largest necrotic area in H-E staining analysis. The tumor cell nucleus, as determined by Ki67 staining, were mostly disappeared.

Conclusion:

Anti-cancer effect of EI236 was synergistically increased in the presence of CDR and/or HT. EI236 may serve as a novel anti-cancer therapy that enables CDR and HT at the same time.

Citation Format: Itaru Sato, Kenji Mitsudo, Masanari Umemura, Xianfeng Feng, Hidenobu Fukumura, Haruki Eguchi, Hideyuki Nakashima, Mitomu Kioi, Iwai Tohnai, Yoshihiro Ishikawa. Thermochemotherapy with controlled drug delivery using a novel magnetic anti-cancer drug . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5568. doi:10.1158/1538-7445.AM2013-5568

Abstract 5570: Targeted drug delivery system and magnetic resonance imaging with intrinsic ferromagnetic nano-particle compound

First principles calculations based on structures obtained by X-ray crystallography analysis are applied to identifying the intrinsic ferromagnetic nano-particle compound. We have found that this organic based nano-particle compound (EI236) exhibits anti-cancer property and, more important, possesses a magnetic property as it was readily attached to a magnet. EI236 exhibited intrinsic ferromagnetic behaviors from -268 celcius degree to 37 celsius degree and inhibited melanoma expansion in mouse tails when delivered to the melanoma lesion using a commercially available magnet. The local accumulation of the compound, as induced by the magnet, was readily visualized by magnetic resonance imaging (MRI) in mice. (n=4) Thus, EI236 acted as both an anti-cancer drug and an MRI contrast, and had pharmacological effects that could be delivered in a controlled manner. The identification of such compounds can overcome the long-standing problems of controlled drug delivery by magnetic force and may dramatically alter our concept of pharmacotherapy in the future, i.e., drug-targeting using a magnet and drug-dosing using MRI.

Citation Format: Haruki Eguchi, Kunio Hirata, Reiko Kurotani, Hidenobu Fukumura, David J. Singh, Masahiro Yamamoto, Itaru Sato, Masanori Umemura, Masaki Yamamoto, Yoji Nagashima, Yoshihiro Ishikawa. Targeted drug delivery system and magnetic resonance imaging with intrinsic ferromagnetic nano-particle compound. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5570. doi:10.1158/1538-7445.AM2013-5570

Abstract 5567: Development of a novel magnetic anti-cancer drug for hyperthermic therapy

Background: Hyperthermic therapy is a type of cancer treatment in which body tissue is exposed to high temperature (up to 113°F). Despite of its effectiveness, it has not been widely used. One reason is that it is technically difficult to increase high temperature only in a target cancer site. To address this issue, we have developed a novel nano-magnetic particle, i.e., EI236. EI236 exhibits not only anti-cancer effect, but also ferromagnetic property. Because of its magnetism, this drug can generate heat by itself when it is exposed to an alternating current magnetic field (ACMF).

Method: We established a rabbit model of VX2 cells (rabbit osteosarcoma) grafted on legs to examine the anti-cancer and hyperthermal effects of EI236 in vivo. Rabbits were divided into five groups; 1) no treatment group 2) intra-venous (iv.) EI236 injection group 3) intra-arterial (ia.) EI236 group 4) ia. Methotrexate (MTX) injection group, and 5) ia. EI236+ACMF group. The volume of tumor was measured daily, and then the samples were harvested and evaluated histologically by HE, Ki67, and TUNEL staining.

Results: The effect of EI236 was similar to that of MTX when EI236 was injected via intra-arterial infusion. Via intra-arterial infusion was more effective than iva intra-venous infusion. When EI236 was injected and the tumor was exposed to ACMF for simultaneous chemotherapeutic and hyperthermal effects, it showed the greatest regression of tumor among all the groups examined. EI236 significantly increased necrosis as determined by HE staining, and further increased it by ACMF. Similarly, EI236 decreased cell proliferation as determined by Ki67, and further decreased it by ACMF. Moreover EI236 increased apoptosis as determined by TUNEL staining, and further increased it by ACMF. These results demonstrated that the exposure of ACMF greatly enhanced the anti-cancer effect of EI236. Taken together, EI236 exhibited simultaneous effects of anti-cancer and thyperthermia.

Conclusion: These results demonstrate that EI236 can provide us in developing a new strategy of simultaneous hyperthermo-chemotherapy in the future.

Citation Format: Masanari Umemura, Hidenobu Fukumura, Itaru Sato, Xianfeng Feng, Haruki Eguchi, Yoshihiro Ishikawa. Development of a novel magnetic anti-cancer drug for hyperthermic therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5567. doi:10.1158/1538-7445.AM2013-5567

Difference in clinical and angiographic characteristics of very late stent thrombosis between drug-eluting and bare-metal stent implantations

BACKGROUND

 Limited data are available with which to compare the clinical characteristics of patients with very late stent thrombosis (VLST) after drug-eluting stent (DES) or bare-metal stent (BMS) implantation. The purpose of this study was to investigate the differences in the characteristics of VLST after DES and BMS implantation by reviewing the clinical and angiographic data.

METHODS AND RESULTS

 A total of 28 patients (30 lesions) with VLST after DES implantation and 33 patients (33 lesions) with VLST after BMS implantation were identified. The occurrence of VLST after BMS implantation (2,647±996 days) was much later than that after DES implantation (1,194±558 days, P<0.001). The number of VLST after DES implantation increased gradually each year; however VLST after BMS implantation started to occur >50 months later, and its number increased subsequently. The prevalence of VLST related to surgical procedures involving discontinuation of antiplatelet therapy in VLST patients was higher after DES implantation (14.3%) than after BMS implantation (0%, P=0.039). Angiographic stent fracture was seen in 36.7% of VLST lesions after DES implantation at different times (464-2,102 days after procedure), while none was seen in VLST lesions after BMS implantation (P<0.001).

CONCLUSIONS

 The timing of VLST was different after DES and BMS implantation. Stent fracture was a specific finding of VLST after DES implantation.