Direct visualization of the three-dimensional shape of skyrmion strings in a noncentrosymmetric magnet.

Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn1.4Pt0.9Pd0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.

The clinical value of PERCIST to predict tumour response and prognosis of patients with oesophageal cancer treated by neoadjuvant chemoradiotherapy.

AIM: To examine whether Positron Emission Tomography Response Criteria in Solid Tumours (PERCIST) is useful to predict tumour response and prognosis of patients with oesophageal cancer who received neoadjuvant chemoradiotherapy (NACRT) followed by surgery. MATERIALS AND METHODS: This multicentre retrospective study included 60 patients with oesophageal cancer who underwent 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (18F-FDG-PET/CT) before and after NACRT prior to surgery from January 2007 and June 2016. The correlation between pathological response and PERCIST was assessed by χ2 test. The prognostic significance was assessed by the Kaplan-Meier method and Cox regression analysis. RESULTS: There were 30 responders and 30 non-responders pathologically. The complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD) were seen in 22, 29, seven, and two patients, respectively. There was a significant correlation between pathological response and PERCIST (p<0.001). Forty patients showed eventual progression, and 20 patients were alive without progression between the start of NACRT and last clinical follow-up (median follow-up period; 27 months [range, 3-107]). Pathological stage and PERCIST were significant for progression-free survival (PFS; p=0.044 and 0.006, respectively) and also significant for overall survival (OS; p=0.009 and 0.001, respectively) at univariate analysis. Pathological lymph node staging was also significant for OS at univariate analysis (p=0.018). At multivariate analysis, PERCIST remained significant and independent for PFS (hazard ratio [HR]: 1.59, p=0.046) and OS (HR: 1.82, p=0.008). CONCLUSION: PERCIST may be useful for predicting tumour response and prognosis of patients with oesophageal cancer who received NACRT.

Ceramide limits phosphatidylinositol-3-kinase C2ß-controlled cell motility in ovarian cancer: potential of ceramide as a metastasis-suppressor lipid.

Targeting cell motility, which is required for dissemination and metastasis, has therapeutic potential for ovarian cancer metastasis, and regulatory mechanisms of cell motility need to be uncovered for developing novel therapeutics. Invasive ovarian cancer cells spontaneously formed protrusions, such as lamellipodia, which are required for generating locomotive force in cell motility. Short interfering RNA screening identified class II phosphatidylinositol 3-kinase C2ß (PI3KC2ß) as the predominant isoform of PI3K involved in lamellipodia formation of ovarian cancer cells. The bioactive sphingolipid ceramide has emerged as an antitumorigenic lipid, and treatment with short-chain C6-ceramide decreased the number of ovarian cancer cells with PI3KC2ß-driven lamellipodia. Pharmacological analysis demonstrated that long-chain ceramide regenerated from C6-ceramide through the salvage/recycling pathway, at least in part, mediated the action of C6-ceramide. Mechanistically, ceramide was revealed to interact with the PIK-catalytic domain of PI3KC2ß and affect its compartmentalization, thereby suppressing PI3KC2ß activation and its driven cell motility. Ceramide treatment also suppressed cell motility promoted by epithelial growth factor, which is a prometastatic factor. To examine the role of ceramide in ovarian cancer metastasis, ceramide liposomes were employed and confirmed to suppress cell motility in vitro. Ceramide liposomes had an inhibitory effect on peritoneal metastasis in a murine xenograft model of human ovarian cancer. Metastasis of PI3KC2ß knocked-down cells was insensitive to treatment with ceramide liposomes, suggesting specific involvement of ceramide interaction with PI3KC2ß in metastasis suppression. Our study identified ceramide as a bioactive lipid that limits PI3KC2ß-governed cell motility, and ceramide is proposed to serve as a metastasis-suppressor lipid in ovarian cancer. These findings could be translated into developing ceramide-based therapy for metastatic diseases.

Transferrin facilitates the formation of DNA double-strand breaks via transferrin receptor 1: the possible involvement of transferrin in carcinogenesis of high-grade serous ovarian cancer.

Fallopian tubal epithelium is a candidate for the origin of high-grade serous ovarian cancer. Transferrin-containing follicular fluid and/or retrograde menstrual blood are possible risk factors for carcinogenesis. Accumulation of DNA double-strand breaks (DNA-DSBs) in the fallopian tubal epithelium is considered to play an important role in the development of cancer. However, the mechanisms by which DNA-DSBs accumulate have not yet been fully elucidated. The hydroxyl radical, which is produced in a Fenton reaction catalyzed by an iron ion, serves as a potent DNA-DSB-inducing molecule, raising the potential of an iron ion transporter of transferrin in the formation of DNA-DSBs. We studied the potential involvement of transferrin in DNA damage and the development of ovarian cancer. Treatment with transferrin facilitated the formation of histone 2AX phosphorylated at Serine 139 (γH2AX), which is known as a DNA-DSB marker, in human fallopian tube secretory epithelial cells and A2780 ovarian cancer cells. Knockdown of transferrin receptor 1 (TfR1), but not transferrin receptor 2, suppressed the transferrin uptake and consequent formation of γH2AX. As hydroxyl radicals in reactive oxygen species (ROS) are involved in DNA-DSBs, the formation of ROS was determined. Treatment with TfR1-specific small interference RNAs significantly diminished transferrin-induced formation of ROS. Moreover, TfR1-dependent uptake of transferrin was revealed to augment the formation of DNA-DSBs in the presence of hydrogen peroxide, which served as a substrate for the Fenton reaction. An ex vivo study with murine fallopian tubes further demonstrated that transferrin treatment introduced DNA-DSBs in the fallopian tubal epithelium. Collectively, these data suggested that the transferrin-TfR1 axis accounts for the induction of DNA-DSBs that potentially lead to DNA damage/genome instability. These findings also suggested that exposure to transferrin initiates and promotes the development of ovarian cancer by aiding the accumulation of DNA-DSBs in the fallopian tubal epithelium.

Immunoglobulin G deposition to nonhemidesmosomal lamina lucida and early neutrophil involvement are characteristic features in a case of anti-p200 pemphigoid.

The ultrastructural characteristics and immunolocalization of in vivo bound immunoglobulin G (IgG) in skin affected by anti-p200 pemphigoid have not been elucidated. To give insight into the mechanism of blister formation we report a new case of anti-p200 pemphigoid, studied with stage-oriented morphological analysis and immunoelectron microscopy. Skin biopsy specimens were evaluated ultrastructurally and histologically with immunohistochemistry. By observing the nonblister site, the blister edge and centre of the blister, we determined that neutrophil infiltration increases gradually at the dermoepidermal junction in association with the destruction of type IV collagen. Ultrastructurally, many neutrophils were observed under the lamina densa, with vacuole formation in the dermis. At the periphery of the blister, the lamina densa became fragmented and was observed either at the roof or the floor of the blister. At the centre of the blister, the lamina densa was mainly observed at the blister floor. Postembedding immunoelectron microscopy demonstrated that the IgG, bound in vivo, localized at the lamina lucida, while the area beneath the hemidesmosomes was spared. Together with the early involvement of neutrophils and the destruction of the basal lamina, we suggest that the binding of autoantibodies to the nonhemidesmosomal lamina lucida may induce inflammation with neutrophils, resulting in blister formation.

Marrow stromal cells induce B7-H1 expression on myeloma cells, generating aggressive characteristics in multiple myeloma.

Tumor-associated B7-H1 molecules inhibit antitumor immunity in some malignancies. We found that B7-H1 expression on patient myeloma cells and human myeloma cell lines (HMCLs) was upregulated by cultivating the cells with autologous stromal cells and the human stromal cell line HS-5. Among major cytokines produced by HS-5 cells, interleukin (IL)-6-induced B7-H1 expression on HMCLs. Moreover, HS-5 cell-mediated B7-H1 expression was downregulated by inhibiting IL-6. B7-H1(+) HMCLs were more proliferative and less susceptible to antimyeloma chemotherapy compared with B7-H1(-) HMCLs. Moreover, the former cells showed higher levels of Bcl-2 and FasL expression than the latter. Finally, B7-H1 molecules on HMCLs induced T-cell apoptosis and anergy of tumor-specific T cells. Consistent with these in vitro observations, patients whose myeloma cells expressed high levels of B7-H1 had higher myeloma cell percentages in the bone marrow (BM) and higher serum lactate dehydrogenase levels compared with other myeloma patients. In addition, B7-H1 expression levels were often upregulated after myeloma patients relapsed or became refractory to therapy. Our data indicate that the BM microenvironment upregulates B7-H1 expression on myeloma cells, which links to the two biological actions of inducing T-cell downregulation and enhancing aggressive myeloma-cell characteristics. Modulating the B7-H1 pathway may be worthwhile in myeloma.

Clinical significance of miR-144-ZFX axis in disseminated tumour cells in bone marrow in gastric cancer cases.

BACKGROUND: We previously reported that bone marrow (BM) was a homing site for gastric cancer (GC) cells leading to haematogenous metastases. There has been little study that microRNAs regulated pathways in malignant cells or host cells in BM, and thereby regulated the progression of GC. METHODS: Both microRNA microarray and gene expression microarray analyses of total RNA from BM were conducted, comparing five early and five advanced GC patients. We focused on miR-144-ZFX axis as a candidate BM regulator of GC progression and validated the origin of the microRNA expression in diverse cell fractions (EpCAM(+)CD45(-), EpCAM(-)CD45(+), and CD14(+)) by magnetic-activated cell sorting (MACS). RESULTS: Quantitative reverse-transcriptase (RT)-PCR analysis validated diminished miR-144 expression in stage IV GC patients with respect to stage I GC patients (t-test, P=0.02), with an inverse correlation to ZFX (ANOVA, P<0.01). Luciferase reporter assays in five GC cell lines indicated their direct binding and validated by western blotting. Pre-miR144 treatment and the resultant repression of ZFX in GC cell lines moderately upregulated their susceptibility to 5-fluorouracil chemotherapy. In MACS-purified BM fractions, the level of miR-144 expression was significantly diminished in disseminated tumour cell fraction (P=0.0005). Diminished miR-144 expression in 93 cases of primary GC indicated poor prognosis. CONCLUSION: We speculate that disseminated cancer cells could survive in BM when low expression of miR-144 permits upregulation of ZFX. The regulation of the miR-144-ZFX axis in cancer cells has a key role in the indicator of the progression of GC cases.

Folliculotropic mycosis fungoides with eosinophilia and CD30+ large-cell transformation: a case with a fatal outcome presenting with multifocal lesions and leonine facies.

Eosinophilia is recognized as a poor prognostic factor in patients with cutaneous T-cell lymphoma (CTCL). We report a case of folliculotropic mycosis fungoides (FMF) presenting with multiple ulcerative nodular lesions and persistent eosinophilia. Severe facial lesions resulted in a leonine appearance. On histopathological examination, nodular infiltration of large CD30+ large cells was seen. When the previous biopsy specimens were reviewed, marked folliculotropism with atypical lymphocytes was identified in previous specimens 20 years before the blastic transformation. CC chemokine receptor 3 was expressed in tumour cells, whereas CXC chemokine receptor 3 was negative. Expression of interleukin (IL)-5 was detected in a few mononuclear lymphoid cells. This case demonstrates that T helper (Th)2-polarized tumour cells may produce Th2 cytokines including IL-5, which suggests that cytokines and chemokines may contribute to persistent eosinophilia and to recruitment of eosinophils into tumour lesions in advanced FMF.

The utility of FDG-PET for detecting multiple primary cancers in hypopharyngeal cancer patients.

AIM: To examine the utility of 2'-[18F]-fluoro-2'-deoxy-D-glucose positron emission tomography (FDG-PET) for detecting multiple primary cancers (MPC) in patients with hypopharyngeal cancer (HPC). PATIENTS, METHODS: Seventy patients with HPC underwent FDG-PET to determine the staging. Routine clinical examinations were carried out, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and oesophagealgastroduodenoscopy (EGDS). The detection rate of synchronous and metachronous cancer was calculated based on FDG-PET alone or FDG-PET combined with clinical routine examination. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy were used to diagnose oesophageal cancer using FDG-PET. RESULTS: Of the 70 patients, 12 (17.1%) had 15 synchronous tumours, and 2 of the 58 remaining patients (3.4%) had metachronous tumours. Oesophageal cancer was discovered most frequently: superficial type (n=6), advanced type (n=4). On a per-patient basis, 11 of 12 patients (91.6%) were diagnosed with synchronous tumours, and on a per-lesion basis, 12 of 15 lesions (80.0%) were detected by FDG-PET. The sensitivity, specificity, accuracy, PPV, and NPV of FDG-PET regarding oesophageal cancer were 70%, 100%, 95.7%, 100%, and 95.2% respectively. Three of the six superficial types were positive on FDG-PET. Both of the metachronous tumour lesions were detected by FDG-PET. CONCLUSION: FDG-PET is useful for estimating the MPC in HPC patients. Since 3 of 10 synchronous oesophageal cancer were missed with PET alone, a combination with EGDS should be considered to exclude synchronous oesophageal cancer.

Fractional allelic loss as a potential biomarker of risk prediction in early-stage mucinous ovarian tumors of low malignant potential.

Ovarian tumors of low malignant potential (LMP) appear to be intermediate between adenomas and ovarian carcinomas. Such tumors are often associated with a significantly better prognosis than for ovarian carcinomas. However, a subset of LMPs can progress and become lethal even in patients with early-stage disease. In order to seek sensitive diagnostic tools to monitor patients after surgical therapy, we performed a genome-wide scan for LOH in 37 early-stage mucinous LMPs using 91 polymorphic microsatellite markers at an average interval of 50 cM across all of the human chromosomes and 25 LOH markers reported to be associated with ovarian carcinoma. Fractional allelic loss (FAL) values were calculated as (loci scored with LOH)/(total informative loci) for each sample. With respect to tumor recurrence, high FAL values were more frequent in recurrent tumors than in non-recurrent tumors. Using the screening markers, FAL values for recurrent tumors were significantly higher than for non-recurrent tumors (19.8% vs 6.3%, respectively, p < 0.0001). Similar results were obtained using the hotspot markers (22.2% vs 7.1%, respectively, p < 0.0001). A significant correlation between FAL values obtained using screening markers and those based on hotspot markers was observed (R = 0.460, p = 0.003). Our findings suggest that a specific type of genetic instability (i.e., chromosomal instability, CIN) may exist in mucinous LMPs, and that this instability may indicate tumors with an aggressive biological nature. Therefore, FAL values may represent a new biomarker for risk prediction in early-stage mucinous LMP tumors.

A case of extremely chemoresistant pure pleomorphic rhabdomyosarcoma of the uterus associated with a high serum LDH level.

BACKGROUND: Pleomorphic rhabdomyosarcoma (RMS) of gynecologic origin is an exceedingly rare, highly malignant tumor. Only a few cases have been reported in the last decades. CASE REPORT: A 60-year-old postmenopausal woman presented with a high LDH level of unknown origin. Ultimately, she was diagnosed with pleomorphic RMS. She underwent total hysterectomy, bilateral salpingo-oophorectomy, left pelvic and paraaortic lymphadenectomy and partial omentectomy. Surgery was followed by systemic chemotherapy and pelvic irradiation. Unfortunately, the patient did not respond to treatment. Her disease course correlated with the fluctuation of plasma LDH levels. Ultimately she died within 20 months of the diagnosis. CONCLUSION: It is important to have better insight and to set a standard multimodal treatment for adult RMS. In addition, plasma LDH levels can be considered as a prognostic marker for RMS, particularly in advanced stage.

KRAS or BRAF mutation status is a useful predictor of sensitivity to MEK inhibition in ovarian cancer.

This study examined the status of KRAS and BRAF mutations, in relation to extracellular signal-regulated protein kinase (ERK) activation in 58 ovarian carcinomas to clarify the clinicopathological and prognostic significance of KRAS/BRAF mutations. Somatic mutations of either KRAS or BRAF were identified in 12 (20.6%) out of 58 ovarian carcinomas. The frequency of KRAS/BRAF mutations in conventional serous high-grade carcinomas (4.0% : 1/25) was significantly lower than that in the other histological type (32.3% : 10/31). Phosphorylated ERK1/2 (p-ERK1/2) expression was identified in 18 (38.2%) out of 45 ovarian carcinomas. KRAS/BRAF mutation was significantly correlated with International Federation of Gynecology and Obstetrics (FIGO) stage I, II (P<0.001), and p-ERK1/2 (P<0.001). No significant correlations between KRAS/BRAF mutations or p-ERK1/2 expression and overall survival were found in patients with ovarian carcinoma treated with platinum and taxane chemotherapy (P=0.2460, P=0.9339, respectively). Next, to clarify the roles of ERK1/2 activation in ovarian cancers harbouring KRAS or BRAF mutations, we inactivated ERK1/2 in ovarian cancer cells using CI-1040. Cl-1040 is a compound that selectively inhibits MAP kinase kinase (MEK), an upstream regulator of ERK1/2, and thus prevents ERK1/2 activation. Profound growth inhibition and apoptosis were observed in CI-1040-treated cancer cells with mutations in either KRAS or BRAF in comparison with the ovarian cancer cells containing wild-type sequences. This was evident in both in vitro and in vivo studies. The findings in this study indicate that an activated ERK1/2 pathway is critical to tumour growth and survival of ovarian cancers with KRAS or BRAF mutations. Furthermore, they suggest that the CI-1040-induced phenotypes depend on the mutational status of KRAS and BRAF in ovarian cancers. Therefore, ovarian cancer patients with KRAS or BRAF mutations may benefit from CI-1040 treatment.

Present status of pancreas transplantation in Japan--donation predominantly from marginal donors and modified surgical technique: report of Japan pancreas transplantation registry.

In Japan, organ donation has been still limited because of the strict donor criteria. The aim of this study was to show the effectiveness of pancreas transplantation (PTx) by analyzing the outcomes even under poor donor conditions. Thirty-six cases of PTx (32 simultaneous pancreas and kidney transplantations [SPK], 4 pancreas after kidney transplantations) performed during the last 8 years were examined especially for donor characteristics. Mean donor age of 41.4 +/- 11.9 years was considerably older compared with that in the United States and Europe; donors aged over 40 years comprised 67% of the total. According to the criteria described by Kapur, 29 cases (81%) in our series would be considered marginal. Thus, to increase blood supply into the pancreatic head, the gastroduodenal artery (GDA) was anastomosed using donor artery to common hepatic artery or iliac Y graft. These procedures were performed in 16 of the 24 cases in which there was liver procurement. Eventually, 34 cases (94%) preserved GDA continuity. Mean total cold ischemic time of pancreatic grafts was 12 hours 15 minutes. Of 214 registrants, 17 patients on the waiting list for SPK died of diabetic complications. To date, patient survival remains 100% with a mean follow-up period of 33 months. Pancreas graft survivals at 1, 3, and 5 years posttransplantation were 92%, 80%, and 80%, respectively. In contrast, kidney survivals were 91%, 91%, and 91%, respectively. The integrity of the pancreas head and duodenum by preservation of the GDA continuity might have decreased the risk associated with the marginal donors.

Indeterminate cell histiocytosis successfully treated with ultraviolet B phototherapy.

Indeterminate cell histiocytosis (ICH) is a rare disorder, characterized by infiltration of the skin by neoplastic cells that are characteristically positive for S-100 and CD1a, but lack Birbeck's granules. A 75-year-old man presented with a 4-year history of multiple papules on the trunk, limbs, face and neck. Skin biopsy revealed dense infiltration of histiocytic cells that were CD1a+/S100+, but lacked Birbeck's granules. No other abnormality was seen during a general examination including a computed tomography scan of the body, gallium scintigraphy, and an abdominal sonography. Broadband ultraviolet B (UVB) treatment was used for the skin lesions, and partial but almost complete remission was obtained. The case suggests that UVB phototherapy is an option for treatment of ICH.

Therapy-related myelodysplasia and acute myeloid leukemia following paclitaxel- and carboplatin-based chemotherapy in an ovarian cancer patient: a case report and literature review.

Alkylating agents have strong leukemogenic potential. There are a number of recent acute myeloid leukemia (t-AML) cases related to previous paclitaxel exposure. These leukemias tend to be of aggressive subtypes with long-latency periods. Unlike previously reported cases, the present case was of the secondary acute megakaryoblastic myeloid leukemia (AML M7) subtype. Additionally, it did not harbor a translocation in chromosome 19. A 73-year-old woman was diagnosed with t-AML M7 with antecedent myelodysplasia. Leukemia followed a second induction of paclitaxel- and carboplatin-based chemotherapy for recurrent ovarian cancer. Her second induction began 25 months after completion of her first course of chemotherapy. The increased incidence of postpaclitaxel leukemia suggests a probable role for paclitaxel as a leukemogenic agent. It highlights the importance of assessing for leukemia risk factors prior to beginning paclitaxel therapy.

Leptin facilitates learning and memory performance and enhances hippocampal CA1 long-term potentiation and CaMK II phosphorylation in rats.

Leptin, an adipocytokine encoded by an obesity gene and expressed in adipose tissue, affects feeding behavior, thermogenesis, and neuroendocrine status via leptin receptors distributed in the brain, especially in the hypothalamus. Leptin may also modulate the synaptic plasticity and behavioral performance related to learning and memory since: leptin receptors are found in the hippocampus, and both leptin and its receptor share structural and functional similarities with the interleukin-6 family of cytokines that modulate long-term potentiation (LTP) in the hippocampus. We therefore examined the effect of leptin on (1) behavioral performance in emotional and spatial learning tasks, (2) LTP at Schaffer collateral-CA1 synapses, (3) presynaptic and postsynaptic activities in hippocampal CA1 neurons, (4) the intracellular Ca(2+) concentration ([Ca(2+)](i)) in CA1 neurons, and (5) the activity of Ca(2+)/calmodulin protein kinase II (CaMK II) in the hippocampal CA1 tissue that exhibits LTP. Intravenous injection of 5 and/or 50mug/kg, but not of 500mug/kg leptin, facilitated behavioral performance in passive avoidance and Morris water-maze tasks. Bath application of 10(-12)M leptin in slice experiments enhanced LTP and increased the presynaptic transmitter release, whereas 10(-10)M leptin suppressed LTP and reduced the postsynaptic receptor sensitivity to N-methyl-d-aspartic acid. The increase in the [Ca(2+)](i) induced by 10(-10)M leptin was two times greater than that induced by 10(-12)M leptin. In addition, the facilitation (10(-12)M) and suppression (10(-10)M) of LTP by leptin was closely associated with an increase and decrease in Ca(2+)-independent activity of CaMK II. Our results show that leptin not only affects hypothalamic functions (such as feeding, thermogenesis, and neuroendocrine status), but also modulates higher nervous functions, such as the behavioral performance related to learning and memory and hippocampal synaptic plasticity.