Relationship between the type of hormone replacement therapy and incidence of breast cancer in Korea

OBJECTIVE

This study aimed to investigate the relationship between hormone replacement therapy (HRT) types and breast cancer (BC) incidence in postmenopausal women in Korea.

METHODS

The nested case-control study used data from the National Health Insurance Service database. Among the women aged ≥50 years who menopaused between 2004 and 2007, BC incidence up to 2017 was analyzed in 36,446 women using or having used HRT for >1 year and in 36,446 women who did not use any HRT for more than 1 year. HRT types and duration were classified into three categories.

RESULTS

BC risk (BCR) decreased with tibolone use for all ages. With HRT initiation in women aged ≥50 years, BCR was lower with tibolone and estrogen-progestogen therapy. HRT for <3 years showed lower BCR with tibolone, while higher BCR was observed with estrogen-only therapy. BCR was lower in women of all ages on HRT for >5 years than in the control group.

CONCLUSIONS

For women in their 50s, tibolone use lowers BCR; for all ages, the use of any HRT for >5 years showed lower BCR in Korea. These divergent results from western countries could be associated with the specific characteristics of BC in Korea.

Soluble Fas ligand drives autoantibody-induced arthritis by binding to DR5/TRAIL-R2

To date, no study has demonstrated that soluble Fas ligand (sFasL)-mediated inflammation is regulated via interaction with Fas in vivo. We found that FasL interacts specifically with tumor necrosis factor receptor superfamily (TNFRSF)10B, also known as death receptor (DR)5. Autoantibody-induced arthritis (AIA) was attenuated in FasL (Fasl^gld/gld)- and soluble FasL (Fasl^Δs/Δs)-deficient mice, but not in Fas (Fas^lpr/lpr and Fas^–/–)- or membrane FasL (Fasl^Δm/Δm)-deficient mice, suggesting sFasL promotes inflammation by binding to a Fas-independent receptor. Affinity purification mass spectrometry analysis using human (h) fibroblast-like synovial cells (FLSCs) identified DR5 as one of several proteins that could be the elusive Fas-independent FasL receptor. Subsequent cellular and biochemical analyses revealed that DR5 interacted specifically with recombinant FasL–Fc protein, although the strength of this interaction was approximately 60-fold lower than the affinity between TRAIL and DR5. A microarray assay using joint tissues from mice with arthritis implied that the chemokine CX3CL1 may play an important downstream role of the interaction. The interaction enhanced Cx3cl1 transcription and increased sCX3CL1 production in FLSCs, possibly in an NF-κB-dependent manner. Moreover, the sFasL–DR5 interaction-mediated CX3CL1–CX3CR1 axis initiated and amplified inflammation by enhancing inflammatory cell influx and aggravating inflammation via secondary chemokine production. Blockade of FasL or CX3CR1 attenuated AIA. Therefore, the sFasL–DR5 interaction promotes inflammation and is a potential therapeutic target.

Liposomal irinotecan plus fluorouracil/leucovorin versus FOLFIRINOX as the second-line chemotherapy for patients with metastatic pancreatic cancer: a multicenter retrospective study of the Korean Cancer Study Group (KCSG)

Background

There is no clear consensus on the recommended second-line treatment for patients with metastatic pancreatic cancer who have disease progression following gemcitabine-based therapy. We retrospectively evaluated the clinical outcomes of liposomal irinotecan (nal-IRI) plus fluorouracil/leucovorin (FL) and FOLFIRINOX (fluorouracil, leucovorin, irinotecan, and oxaliplatin) in patients who had failed on the first-line gemcitabine-based therapy.

Patients and methods

From January 2015 to August 2019, 378 patients with MPC who had received nal-IRI/FL (n = 104) or FOLFIRINOX (n = 274) as second-line treatment across 11 institutions were included in this retrospective study.

Results

There were no significant differences in baseline characteristics between groups, except age and first-line regimens. With a median follow-up of 6 months, the median progression-free survival (PFS) was 3.7 months with nal-IRI/FL versus 4.6 months with FOLFIRINOX (P = 0.44). Median overall survival (OS) was 7.7 months with nal-IRI/FL versus 9.7 months with FOLFRINOX (P = 0.13). There was no significant difference in PFS and OS between the two regimens in the univariate and multivariate analyses. The subgroup analysis revealed that younger age (<70 years) was associated with better OS with FOLFIRINOX. In contrast, older age (≥70 years) was associated with better survival outcomes with nal-IRI/FL. Adverse events were manageable with both regimens; however, the incidence of grade 3 or higher neutropenia and peripheral neuropathy was higher in patients treated with FOLFIRINOX than with nal-IRI/FL.

Conclusions

Second-line nal-IRI/FL and FOLFIRINOX showed similar effectiveness outcomes after progression following first-line gemcitabine-based therapy. Age could be the determining factor for choosing the appropriate second-line therapy.

•

This multicenter retrospective study investigated nal-IRI/FL and FOLFIRINOX outcomes after gemcitabine-based therapy.

•

We found no significant differences in outcome between nal-IRI/FL and FOLFIRINOX treatment.

•

Both regimens were well tolerated; however, neutropenia and peripheral neuropathy were more frequent with FOLFIRINOX.

•

Age (cut-off, 70 years) showed differential efficacy between chemotherapy regimens.

O-Linked N-Acetylglucosamine Modification of Mitochondrial Antiviral Signaling Protein Regulates Antiviral Signaling by Modulating Its Activity

Post-translational modifications, including O-GlcNAcylation, play fundamental roles in modulating cellular events, including transcription, signal transduction, and immune signaling. Several molecular targets of O-GlcNAcylation associated with pathogen-induced innate immune responses have been identified; however, the direct regulatory mechanisms linking O-GlcNAcylation with antiviral RIG-I-like receptor signaling are not fully understood. In this study, we found that cellular levels of O-GlcNAcylation decline in response to infection with Sendai virus. We identified a heavily O-GlcNAcylated serine-rich region between amino acids 249–257 of the mitochondrial antiviral signaling protein (MAVS); modification at this site disrupts MAVS aggregation and prevents MAVS-mediated activation and signaling. O-GlcNAcylation of the serine-rich region of MAVS also suppresses its interaction with TRAF3; this prevents IRF3 activation and production of interferon-β. Taken together, these results suggest that O-GlcNAcylation of MAVS may be a master regulatory event that promotes host defense against RNA viruses.

Long-term mortality of patients with tuberculosis in Korea

BACKGROUND: Long-term mortality following tuberculosis (TB) diagnosis in Korea remains unclear.METHODS: The present study used data from the National Health Insurance Service database, an extensive health-related database including most Korean residents. TB patients were identified using International Classification of Diseases, Tenth Revision coding (A15-19, U88.0-88.1) and the type of anti-TB drug(s) between 2003 and 2016. Long-term mortality and causes of death in TB patients were analysed.RESULTS: A total of 357 211 individuals had TB over the period from 2003 to 2016 and 103 682 died. The mean age of the cohort was 54.7 ± 20.7 years, and 59.8% were male. The survival probability of TB patients at 1, 5, and 10 years after diagnosis was 87.8%, 75.3%, and 63.3%, respectively. High mortality and TB-related death rates were especially prominent in the early stages after TB diagnosis. The overall standardized mortality ratio of TB patients to the general Korean population was 3.23 (95% confidence interval 3.21-3.25).CONCLUSION: Mortality in TB patients was especially high in the early stages of disease after TB diagnosis, and mostly due to TB. This figure was approximately three-times higher than the mortality rate in the general population.

Incidence, survival, and risk of cardiovascular events in adult inflammatory myopathies in South Korea: a nationwide population-based study

OBJECTIVE

Epidemiological studies on inflammatory myopathies (IMs) show widely variable results, and studies on Asians are lacking. Despite emerging interest in the cardiovascular disease (CVD) risk associated with IMs, the prevalence of CVD in IM patients and its impact on mortality remain unclear. We conducted a nationwide, population-based study on the incidence, mortality, and associated major CVD events of IMs in the Republic of Korea over 11 years.

METHOD

Using the nationwide, population-based National Health Insurance claims database and the Rare Intractable Disease registration programme, we estimated incidence, mortality, and CVD occurrence. Survival was examined using the Kaplan-Meier method. Mortality rate in IMs with CVD was analysed by Cox proportional hazards regression.

RESULTS

There were 3014 incident cases, 640 of whom died during the study period. The mean annual incidence was 7.16/10⁶. Dermatomyositis (DM) and polymyositis (PM) had 5 year survival rates of 76.8% and 79.3%, respectively. Cardiovascular events occurred in 155 patients and 40.6% of IM patients with CVD died. Acute myocardial infarction in men had the highest risk of any CVD event in both DM [standardized incidence ratio (SIR) 4.2, 95% confidence interval (95% CI) 2.4-7.2] and PM (SIR 3.5, 95% CI 1.8-7.0). Haemorrhagic stroke had the highest hazard ratio (HR) in both DM (HR 2.31, 95% CI 1.13-4.70) and PM patients (HR 2.10, 95% CI 1.03-4.27) compared with the general population with CVD.

CONCLUSION

We found persistently low incidence, poor survival, and high major CVD incidence in IMs, and increased mortality in IMs with CVD.

The Amniotic Fluid Proteome Differs Significantly between Donor and Recipient Fetuses in Pregnancies Complicated by Twin-to-Twin Transfusion Syndrome

BACKGROUND

Twin-to-twin transfusion syndrome (TTTS) is a serious complication of monochorionic twin pregnancies. It results from disproportionate blood supply to each fetus caused by abnormal vascular anastomosis within the placenta. Amniotic fluid (AF) is an indicator reflecting the various conditions of the fetus, and an imbalance in AF volume is essential for the antenatal diagnosis of TTTS by ultrasound. In this study, two different mass spectrometry quantitative approaches were performed to identify differentially expressed proteins (DEPs) within matched pairs of AF samples.

METHODS

We characterized the AF proteome in pooled AF samples collected from donor and recipient twin pairs (n = 5 each) with TTTS by a global proteomics profiling approach and then preformed the statistical analysis to determine the DEPs between the two groups. Next, we carried out a targeted proteomic approach (multiple reaction monitoring) with DEPs to achieve high-confident TTTS-associated AF proteins.

RESULTS

A total of 103 AF proteins that were significantly altered in their abundances between donor and recipient fetuses. The majority of upregulated proteins identified in the recipient twins (including carbonic anhydrase 1, fibrinogen alpha chain, aminopeptidase N, alpha-fetoprotein, fibrinogen gamma chain, and basement membrane-specific heparan sulfate proteoglycan core protein) have been associated with cardiac or dermatologic disease, which is often seen in recipient twins as a result of volume overload. In contrast, proteins significantly upregulated in AF collected from donor twins (including IgGFc-binding protein, apolipoprotein C-I, complement C1q subcomponent subunit B, apolipoprotein C-III, apolipoprotein A-II, decorin, alpha-2-macroglobulin, apolipoprotein A-I, and fibronectin) were those previously shown to be associated with inflammation, ischemic cardiovascular complications or renal disease.

CONCLUSION

In this study, we identified proteomic biomarkers in AF collected from donor and recipient twins in pregnancies complicated by TTTS that appear to reflect underlying functional and pathophysiological challenges faced by each of the fetuses.

Efficacy and safety findings from DREAM: a phase III study of DHP107 (oral paclitaxel) versus i.v. paclitaxel in patients with advanced gastric cancer after failure of first-line chemotherapy

Background

Paclitaxel is currently only available as an intravenous (i.v.) formulation. DHP107 is a novel oral formulation of lipid ingredients and paclitaxel. DHP107 demonstrated comparable efficacy, safety, and pharmacokinetics to i.v. paclitaxel as a second-line therapy in patients with advanced gastric cancer (AGC). DREAM is a multicenter, open-label, prospective, randomized phase III study of patients with histologically/cytologically confirmed, unresectable/recurrent AGC after first-line therapy failure.

Methods and materials

Patients were randomized 1 : 1 to DHP107 (200 mg/m2 orally twice daily days 1, 8, 15 every 4 weeks) or i.v. paclitaxel (175 mg/m2 day 1 every 3 weeks). Patients were stratified by Eastern Cooperative Oncology Group performance status, disease status, and prior treatment; response was assessed (Response Evaluation Criteria in Solid Tumors) every 6 weeks. Primary end point: non-inferiority of progression-free survival (PFS); secondary end points: overall response rate (ORR), overall survival (OS), and safety. For the efficacy analysis, sequential tests for non-inferiority were carried out, first with a non-inferiority margin of 1.48, then with a margin of 1.25.

Results

Baseline characteristics were balanced in the 236 randomized patients (n = 118 per arm). Median PFS (per-protocol) was 3.0 (95% CI 1.7-4.0) months for DHP107 and 2.6 (95% CI 1.8-2.8) months for paclitaxel (hazard ratio [HR] = 0.85; 95% CI 0.64-1.13). A sensitivity analysis on PFS using independent central review showed similar results (HR = 0.93; 95% CI 0.70-1.24). Median OS (full analysis set) was 9.7 (95% CI 7.1 - 11.5) months for DHP107 versus 8.9 (95% CI 7.1-12.2) months for paclitaxel (HR = 1.04; 95% CI 0.76-1.41). ORR was 17.8% for DHP107 (CR 4.2%; PR 13.6%) versus 25.4% for paclitaxel (CR 3.4%; PR 22.0%). Nausea, vomiting, diarrhea, and mucositis were more common with DHP107; peripheral neuropathy was more common with paclitaxel. There were only few Grade≥3 adverse events, most commonly neutropenia (42% versus 53%); febrile neutropenia was reported infrequently (5.9% versus 2.5%). No hypersensitivity reactions occurred with DHP107 (paclitaxel 2.5%).

Conclusions

DHP107 as a second-line treatment of AGC was non-inferior to paclitaxel for PFS; other efficacy and safety parameters were comparable. DHP107 is the first oral paclitaxel with proven efficacy/safety for the treatment of AGC.

ClinicalTrials.gov

NCT01839773.

Correction to: Post-translational modification of OCT4 in breast cancer tumorigenesis

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The N-recognin UBR4 of the N-end rule pathway is targeted to and required for the biogenesis of the early endosome

The N-end rule pathway is a proteolytic system in which single N-terminal residues of proteins act as N-degrons. These degrons are recognized by N-recognins, facilitating substrate degradation via the ubiquitin (Ub) proteasome system (UPS) or autophagy. We have previously identified a set of N-recognins [UBR1, UBR2, UBR4 (also known as p600) and UBR5 (also known as EDD)] that bind N-degrons through their UBR boxes to promote proteolysis by the proteasome. Here, we show that the 570 kDa N-recognin UBR4 is associated with maturing endosomes through an interaction with Ca²⁺-bound calmodulin. The endosomal recruitment of UBR4 is essential for the biogenesis of early endosomes (EEs) and endosome-related processes, such as the trafficking of endocytosed protein cargos and degradation of extracellular cargos by endosomal hydrolases. In mouse embryos, UBR4 marks and plays a role in the endosome-lysosome pathway that mediates the heterophagic proteolysis of endocytosed maternal proteins into amino acids. By screening 9591 drugs through the DrugBank database, we identify picolinic acid as a putative ligand for UBR4 that inhibits the biogenesis of EEs. Our results suggest that UBR4 is an essential modulator in the endosome-lysosome system.This article has an associated First Person interview with the first author of the paper.

The N-recognin UBR4 of the N-end rule pathway is required for neurogenesis and homeostasis of cell surface proteins

The N-end rule pathway is a proteolytic system in which single N-terminal amino acids of proteins act as a class of degrons (N-degrons) that determine the half-lives of proteins. We have previously identified a family of mammals N-recognins (termed UBR1, UBR2, UBR4/p600, and UBR5/EDD) whose conserved UBR boxes bind N-degrons to facilitate substrate ubiquitination and proteasomal degradation via the ubiquitin-proteasome system (UPS). Amongst these N-recognins, UBR1 and UBR2 mediate ubiquitination and proteolysis of short-lived regulators and misfolded proteins. Here, we characterized the null phenotypes of UBR4-deficient mice in which the UBR box of UBR4 was deleted. We show that the mutant mice die around embryonic days 9.5–10.5 (E9.5–E10.5) associated with abnormalities in various developmental processes such as neurogenesis and cardiovascular development. These developmental defects are significantly attributed to the inability to maintain cell integrity and adhesion, which significantly correlates to the severity of null phenotypes. UBR4-loss induces the depletion of many, but not all, proteins from the plasma membrane, suggesting that UBR4 is involved in proteome-wide turnover of cell surface proteins. Indeed, UBR4 is associated with and required to generate the multivesicular body (MVB) which transiently store endocytosed cell surface proteins before their targeting to autophagosomes and subsequently lysosomes. Our results suggest that the N-recognin UBR4 plays a role in the homeostasis of cell surface proteins and, thus, cell adhesion and integrity.

Apolipoprotein B binds to enolase-1 and aggravates inflammation in rheumatoid arthritis

OBJECTIVE

Immune cells from patients with rheumatoid arthritis (RA) express more enolase-1 (ENO1) on their surface than those from healthy subjects, and they elicit an enhanced inflammatory response. This study is aimed to identify the ligands of ENO1 that could promote inflammatory loops in vitro and enhance the arthritis severity in vivo.

METHODS

ENO1-binding proteins in RA synovial fluid were identified by mass spectromety, and affinity to ENO1 was evaluated by means of a ligand blotting and binding assay, surface plasmon resonance and confocal microscopy. Proinflammatory response by the interaction between ENO1 and apolipoprotein B (apoB) was tested in vitro and in vivo using peripheral blood mononuclear cells and a K/BxN serum transfer arthritis model and low-density lipoproteins receptor (LDLR) knockout mice.

RESULTS

ApoB in the synovid fluid of patients with RA was identified as a specific ligand to ENO1 with a higher affinity than plasminogen, a known ENO1 ligand. ApoB binding to ENO1 on monocytes elicited the production of tumour necrosis factor-α, interleukins (IL)-1β and IL-6 through both p38 mitogen-activated protein kinase and NF-κB pathways. In the K/BxN serum transfer arthritis model, administration of apoB increased the production of proinflammatory cytokines and exaggerated arthritis severity. The severity of K/BxN serum transfer arthritis in LDLR knockout mice was comparable with wild-type mice.

CONCLUSIONS

A key component of atherogenic lipids, apoB, aggravated arthritis by potentiating the inflammatory response via its interaction with ENO1 expressed on the surface of immune cells. This suggests a novel mechanism by which lipid metabolism regulates chronic inflammation in RA.

Urinary vitamin D-binding protein, a novel biomarker for lupus nephritis, predicts the development of proteinuric flare

Lupus nephritis (LN) is a major complication of systemic lupus erythematosus (SLE). Conventional biomarkers for assessing renal disease activity are imperfect in predicting clinical outcomes associated with LN. The aim of this study is to identify urinary protein biomarkers that reliably reflect the disease activity or predict clinical outcomes. A quantitative proteomic analysis was performed to identify protein biomarker candidates that can differentiate between SLE patients with and without LN. Selected biomarker candidates were further verified by enzyme-linked immunosorbent assay using urine samples from a larger cohort of SLE patients ( n = 121) to investigate their predictive values for LN activity measure. Furthermore, the association between urinary levels of a selected panel of potential biomarkers and prognosis of LN was assessed with a four-year follow-up study of renal outcomes. Urinary vitamin D-binding protein (VDBP), transthyretin (TTR), retinol binding protein 4 (RBP4), and prostaglandin D synthase (PTGDS) were significantly elevated in SLE patients with LN, especially in patients with active LN ( n = 21). Among them, VDBP well correlated with severity of proteinuria (rho = 0.661, p < 0.001) and renal SLE Disease Activity Index (renal SLEDAI) (rho = 0.520, p < 0.001). In the four-year follow-up, VDBP was a significant risk factor (hazard ratio 9.627, 95% confidence interval 1.698 to 54.571, p = 0.011) for the development of proteinuric flare in SLE patients without proteinuria ( n = 100) after adjustments for multiple confounders. Urinary VDBP correlated with proteinuria and renal SLEDAI, and predicted the development of proteinuria.

A point mutation in the heavy chain complementarity-determining region 3 (HCDR3) significantly enhances the specificity of an anti-ROS1 antibody

The proto-oncogene tyrosine kinase ROS1 plays a key role in carcinogenesis through gene rearrangement to form a fusion protein with other genes, in which the C-terminal intracellular region of ROS1 participates. The possibility of wild type ROS1 overexpression through epigenetic regulation has been proposed. Here, we generated an antibody, 3B20, reactive to the N-terminal region of ROS1 to use it for the detection of wild type ROS1 in cancerous tissues. Using immunoblot and immunoprecipitation analyses, we found that 3B20 also reacted with heat shock proteins (Hsp)70s. Using homology searching, ROS1 and Hsp70s were found to share an identical amino acid sequence: DLGT. Using alanine mutagenesis of ROS1, the epitope was found to harbor this sequence. To modify the idiotope with the aim of selecting more specific antibodies, we introduced random mutations into the heavy chain complementarity-determining region 3 and successfully generated an antibody clone, 3B20-G1K, with a point mutation that only reacted with ROS1 in enzyme-linked immunosorbent assays, and in immunoblot and immunoprecipitation analysis. In immunohistochemical analysis using 3B20-G1K, ROS1 was found to be absent in normal lung tissues and was overexpressed in a case of lung adenocarcinoma.

Expression changes of proteins associated with the development of preeclampsia in maternal plasma: A case-control study

Defective deep placentation, involving abnormal transformation of the spiral arteries in the junctional zone of the myometrium, is known to cause significant obstetric complications, such as preeclampsia (PE), fetal growth restriction, and placental infarction leading to fetal death. Serological biomarkers to predict and diagnose PE would help antenatal care and reduce obstetric complications. To discover candidate PE biomarkers, we first performed global proteomic profiling of three pairs of plasma samples obtained from pregnant women in the early second trimester, who subsequently developed PE, and controls to identify candidate proteins that were abundant in the patients. We further evaluated the changes in the expression of PE-representing proteins in stored plasma samples of a cohort that subsequently developed PE and their matched controls by MRM-MS analysis. We identified that both complement C1s subcomponent (C1S) and protein AMBP were elevated in the plasma samples of the PE cohort before the manifestation of clinical disease. We propose that these proteins may be involved in the remodeling process of the spiral arteries even before PE manifestation. These proteins can serve as potential plasma biomarkers to predict the pregnant women having an increased risk of developing PE.

Identification of the nuclear localisation signal of O-GlcNAc transferase and its nuclear import regulation

Nucleocytoplasmic O-GlcNAc transferase (OGT) attaches a single GlcNAc to hydroxyl groups of serine and threonine residues. Although the cellular localisation of OGT is important to regulate a variety of cellular processes, the molecular mechanisms regulating the nuclear localisation of OGT is unclear. Here, we characterised three amino acids (DFP; residues 451-453) as the nuclear localisation signal of OGT and demonstrated that this motif mediated the nuclear import of non-diffusible β-galactosidase. OGT bound the importin α5 protein, and this association was abolished when the DFP motif of OGT was mutated or deleted. We also revealed that O-GlcNAcylation of Ser389, which resides in the tetratricopeptide repeats, plays an important role in the nuclear localisation of OGT. Our findings may explain how OGT, which possesses a NLS, exists in the nucleus and cytosol simultaneously.

Randomized multicentre trial comparing external and internal pancreatic stenting during pancreaticoduodenectomy

BACKGROUND

There is no consensus on the best method of preventing postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD). This multicentre, parallel group, randomized equivalence trial investigated the effect of two ways of pancreatic stenting after PD on the rate of POPF.

METHODS

Patients undergoing elective PD or pylorus-preserving PD with duct-to-mucosa pancreaticojejunostomy were enrolled from four tertiary referral hospitals. Randomization was stratified according to surgeon with a 1 : 1 allocation ratio to avoid any related technical factors. The primary endpoint was clinically relevant POPF rate. Secondary endpoints were nutritional index, remnant pancreatic volume, long-term complications and quality of life 2 years after PD.

RESULTS

A total of 328 patients were randomized to the external (164 patients) or internal (164) stent group between August 2010 and January 2014. The rates of clinically relevant POPF were 24·4 per cent in the external and 18·9 per cent in the internal stent group (risk difference 5·5 per cent). As the 90 per cent confidence interval (-2·0 to 13·0 per cent) did not fall within the predefined equivalence limits (-10 to 10 per cent), the clinically relevant POPF rates in the two groups were not equivalent. Similar results were observed for patients with soft pancreatic texture and high fistula risk score. Other postoperative outcomes were comparable between the two groups. Five stent-related complications occurred in the external stent group. Multivariable analysis revealed that soft pancreatic texture, non-pancreatic disease and high body mass index (23·3 kg/m² or above) predicted clinically relevant POPF.

CONCLUSION

External stenting after PD was associated with a higher rate of clinically relevant POPF than internal stenting. Registration number: NCT01023594 (https://www.clinicaltrials.gov).

Mitochondrial ATP synthase activity is impaired by suppressed O-GlcNAcylation in Alzheimer's disease

Glycosylation with O-linked β-N-acetylglucosamine (O-GlcNAc) is one of the protein glycosylations affecting various intracellular events. However, the role of O-GlcNAcylation in neurodegenerative diseases such as Alzheimer's disease (AD) is poorly understood. Mitochondrial adenosine 5'-triphosphate (ATP) synthase is a multiprotein complex that synthesizes ATP from ADP and Pi. Here, we found that ATP synthase subunit α (ATP5A) was O-GlcNAcylated at Thr432 and ATP5A O-GlcNAcylation was decreased in the brains of AD patients and transgenic mouse model, as well as Aβ-treated cells. Indeed, Aβ bound to ATP synthase directly and reduced the O-GlcNAcylation of ATP5A by inhibition of direct interaction between ATP5A and mitochondrial O-GlcNAc transferase, resulting in decreased ATP production and ATPase activity. Furthermore, treatment of O-GlcNAcase inhibitor rescued the Aβ-induced impairment in ATP production and ATPase activity. These results indicate that Aβ-mediated reduction of ATP synthase activity in AD pathology results from direct binding between Aβ and ATP synthase and inhibition of O-GlcNAcylation of Thr432 residue on ATP5A.

Increased TRPC5 glutathionylation contributes to striatal neuron loss in Huntington's disease

Aberrant glutathione or Ca(2+) homeostasis due to oxidative stress is associated with the pathogenesis of neurodegenerative disorders. The Ca(2+)-permeable transient receptor potential cation (TRPC) channel is predominantly expressed in the brain, which is sensitive to oxidative stress. However, the role of the TRPC channel in neurodegeneration is not known. Here, we report a mechanism of TRPC5 activation by oxidants and the effect of glutathionylated TRPC5 on striatal neurons in Huntington's disease. Intracellular oxidized glutathione leads to TRPC5 activation via TRPC5 S-glutathionylation at Cys176/Cys178 residues. The oxidized glutathione-activated TRPC5-like current results in a sustained increase in cytosolic Ca(2+), activated calmodulin-dependent protein kinase and the calpain-caspase pathway, ultimately inducing striatal neuronal cell death. We observed an abnormal glutathione pool indicative of an oxidized state in the striatum of Huntington's disease transgenic (YAC128) mice. Increased levels of endogenous TRPC5 S-glutathionylation were observed in the striatum in both transgenic mice and patients with Huntington's disease. Both knockdown and inhibition of TRPC5 significantly attenuated oxidation-induced striatal neuronal cell death. Moreover, a TRPC5 blocker improved rearing behaviour in Huntington's disease transgenic mice and motor behavioural symptoms in littermate control mice by increasing striatal neuron survival. Notably, low levels of TRPC1 increased the formation of TRPC5 homotetramer, a highly Ca(2+)-permeable channel, and stimulated Ca(2+)-dependent apoptosis in Huntington's disease cells (STHdh(Q111/111)). Taken together, these novel findings indicate that increased TRPC5 S-glutathionylation by oxidative stress and decreased TRPC1 expression contribute to neuronal damage in the striatum and may underlie neurodegeneration in Huntington's disease.

Identification of a novel splice variant of neuronal nitric oxide synthase, nNOSβ, in myofilament fraction of murine cardiomyocytes

Splice variant forms of neuronal nitric oxide synthase (nNOS or NOS1), nNOSα and nNOSμ, are well established to be functionally expressed in discrete compartments in cardiomyocytes (e.g. sarcoplasmic reticulum, SR, caveolae in plasma membrane or mitochondria). So far, whether nNOS is expressed in myofilament fraction of cardiomyocytes and the splice variant form of nNOS are unknown. Immunoblotting results using two nNOS specific antibodies (BD Transduction Laboratories aa 1095-1289 and Santa Cruz Biotechnology aa 2-300) clearly demonstrated that nNOS was abundantly expressed in myofilament-enriched fraction of cardiomyocytes. Whilst the molecular weight of nNOS in membrane/cytosol fractions was ∼165 kDa, nNOS in myofilament was below 140 kDa, suggesting that the predominant splice variant of nNOS in myofilament is nNOSβ. RT-PCR results confirmed the expressions of both nNOSα and nNOSβ mRNAs in rat cardiomyocytes. Similarly, immunoprecipitation experiments using myofilament lysates of cardiomyocytes identified nNOS with low molecular weight (M.W. ∼140 kDa), confirming nNOSβ. Intriguingly, all three splice variants of nNOS were undetectable in the lysates of cardiomyocytes (including myofilament fractions) from nNOS^-/- mice (which lacks nNOSα/μ). Furthermore, nNOSβ expression in myofilament of cardiomyocytes was not different in hypertensive rats compared to the level expressed in sham. iTRAQ-based quantitative proteomics analysis revealed that nNOS regulates phosphorylations of ∼20 proteins in cardiac myofilaments. Collectively, we provide direct evidence that different splice variants of nNOS are expressed in myofilament and membrane/cytosol fractions of cardiomyocytes. Discrete expressions of various splice variants in different compartments of cardiomyocytes suggest diverse roles nNOS play in healthy and diseased heart.

Ctbp2 Modulates NuRD-Mediated Deacetylation of H3K27 and Facilitates PRC2-Mediated H3K27me3 in Active Embryonic Stem Cell Genes During Exit from Pluripotency

For cells to exit from pluripotency and commit to a lineage, the circuitry of a core transcription factor (CTF) network must be extinguished in an orderly manner through epigenetic modifications. However, how this choreographed epigenetic remodeling at active embryonic stem cell (ESC) genes occurs during differentiation is poorly understood. In this study, we demonstrate that C-terminal binding protein 2 (Ctbp2) regulates nucleosome remodeling and deacetylation (NuRD)-mediated deacetylation of H3K27 and facilitates recruitment of polycomb repressive complex 2 (PRC2)-mediated H3K27me3 in active ESC genes for exit from pluripotency during differentiation. By genomewide analysis, we found that Ctbp2 resides in active ESC genes and co-occupies regions with ESC CTFs in undifferentiated ESCs. Furthermore, ablation of Ctbp2 effects inappropriate gene silencing in ESCs by sustaining high levels of H3K27ac and impeding H3K27me3 in active ESC genes, thereby sustaining ESC maintenance during differentiation. Thus, Ctbp2 preoccupies regions in active genes with the NuRD complex in undifferentiated ESCs that are directed toward H3K27me3 by PRC2 to induce stable silencing, which is pivotal for natural lineage commitment.

Heme-binding-mediated negative regulation of the tryptophan metabolic enzyme indoleamine 2,3-dioxygenase 1 (IDO1) by IDO2

Indoleamine 2,3-dioxygenases (IDOs) are tryptophan-catabolizing enzymes with immunomodulatory functions. However, the biological role of IDO2 and its relationship with IDO1 are unknown. To assess the relationship between IDO2 and IDO1, we investigated the effects of co-expression of human (h) IDO2 on hIDO1 activity. Cells co-expressing hIDO1 and hIDO2 showed reduced tryptophan metabolic activity compared with those expressing hIDO1 only. In a proteomic analysis, hIDO1-expressing cells exhibited enhanced expression of proteins related to the cell cycle and amino acid metabolism, and decreased expression of proteins related to cell survival. However, cells co-expressing hIDO1 and hIDO2 showed enhanced expression of negative regulators of cell apoptosis compared with those expressing hIDO1 only. Co-expression of hIDO1 and hIDO2 rescued the cell death induced by tryptophan-depletion through hIDO1 activity. Cells expressing only hIDO2 exhibited no marked differences in proteome profiles or cell growth compared with mock-transfectants. Cellular tryptophan metabolic activity and cell death were restored by co-expressing the hIDO2 mutant substituting the histidine 360 residue for alanine. These results demonstrate that hIDO2 plays a novel role as a negative regulator of hIDO1 by competing for heme-binding with hIDO1, and provide information useful for development of therapeutic strategies to control cancer and immunological disorders that target IDO molecules.

Portal vein patency after pancreatoduodenectomy for periampullary cancer

BACKGROUND

The fate of the portal vein (PV) after pancreatoduodenectomy, especially its long-term patency and associated complications, has received little attention. The aim of this study was to explore the long-term patency rate of the PV after pancreatoduodenectomy, focusing on risk factors for PV stenosis/occlusion and associated complications.

METHODS

Serial CT images of patients who underwent pancreatoduodenectomy for periampullary cancer between January 2000 and June 2012 in a single institution were evaluated for PV stenosis or occlusion.

RESULTS

A total of 826 patients were enrolled. The PV stenosis/occlusion rate after pancreatoduodenectomy was 19.6 per cent and the 5-year patency rate 69.9 per cent. The most frequent cause of PV stenosis/occlusion was local recurrence followed by postoperative change and PV thrombosis. Patients who underwent PV resection had a higher PV stenosis/occlusion rate than those who did not (51 versus 17.4 per cent; P < 0.001). The 3-year patency rate was highest in patients with cancer of the ampulla of Vater and lowest in patients with pancreatic cancer (91.9 versus 55.5 per cent respectively; P < 0.001). Multivariable analysis showed that risk factors for PV stenosis/occlusion included primary tumour location, chemoradiotherapy and PV resection. PV stenosis or occlusion without disease recurrence was observed in 17.3 per cent of the patients. PV resection and grade B or C pancreatic fistula were independent risk factors for PV stenosis/occlusion. Among 162 patients with PV stenosis or occlusion, five (3.1 per cent) had fatal recurrent gastrointestinal bleeding.

CONCLUSION

PV stenosis or occlusion is common after pancreatoduodenectomy, particularly if the PV has been resected and/or chemoradiotherapy was given after surgery. Although recurrence is the most frequent cause of PV stenosis/occlusion, this complication is found in a significant proportion of patients without disease recurrence.

Urinary proteome profile predictive of disease activity in rheumatoid arthritis

Current serum biomarkers for rheumatoid arthritis (RA) are not highly sensitive or specific to changes of disease activities. Thus, other complementary biomarkers have been needed to improve assessment of RA activities. In many diseases, urine has been studied as a window to provide complementary information to serum measures. Here, we conducted quantitative urinary proteome profiling using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and identified 134 differentially expressed proteins (DEPs) between RA and osteoarthritis (OA) urine samples. By integrating the DEPs with gene expression profiles in joints and mononuclear cells, we initially selected 12 biomarker candidates related to joint pathology and then tested their altered expression in independent RA and OA samples using enzyme-linked immunosorbent assay. Of the initial candidates, we selected four DEPs as final candidates that were abundant in RA patients and consistent with those observed in LC-MS/MS analysis. Among them, we further focused on urinary soluble CD14 (sCD14) and examined its diagnostic value and association with disease activity. Urinary sCD14 had a diagnostic value comparable to conventional serum measures and an even higher predictive power for disease activity when combined with serum C-reactive protein. Thus, our urinary proteome provides a diagnostic window complementary to current serum parameters for the disease activity of RA.

Identification of novel autoantibodies in type 1 diabetic patients using a high-density protein microarray

Autoantibodies can facilitate diagnostic and therapeutic means for type 1 diabetes (T1DM). We profiled autoantibodies from serum samples of 16 T1DM patients, 16 type 2 diabetic (T2DM) patients, and 27 healthy control subjects with normal glucose tolerance (NGT) by using protein microarrays containing 9,480 proteins. Two novel autoantibodies, anti-EEF1A1 and anti-UBE2L3, were selected from microarrays followed by immunofluorescence staining of pancreas. We then tested the validity of the candidates by ELISA in two independent test cohorts: 1) 95 adults with T1DM, 49 with T2DM, 11 with latent autoimmune diabetes in adults (LADA), 20 with Graves disease, and 66 with NGT and 2) 33 children with T1DM and 34 healthy children. Concentrations of these autoantibodies were significantly higher in T1DM patients than in NGT and T2DM subjects (P < 0.01), which was also confirmed in the test cohort of children (P < 0.05). Prevalence of anti-EEF1A1 and anti-UBE2L3 antibodies was 29.5% and 35.8% in T1DM, respectively. Of note, 40.9% of T1DM patients who lack anti-GAD antibodies (GADA) had anti-EEF1A1 and/or anti-UBE2L3 antibodies. These were also detected in patients with fulminant T1DM but not LADA. Our approach identified autoantibodies that can provide a new dimension of information indicative of T1DM independent of GADA and new insights into diagnosis and classification of T1DM.

Crucial role of calbindin-D28k in the pathogenesis of Alzheimer's disease mouse model

Calbindin-D_28k (CB), one of the major calcium-binding and buffering proteins, has a critical role in preventing a neuronal death as well as maintaining calcium homeostasis. Although marked reductions of CB expression have been observed in the brains of mice and humans with Alzheimer disease (AD), it is unknown whether these changes contribute to AD-related dysfunction. To determine the pathogenic importance of CB depletions in AD models, we crossed 5 familial AD mutations (5XFAD; Tg) mice with CB knock-out (CBKO) mice and generated a novel line CBKO·5XFAD (CBKOTg) mice. We first identified the change of signaling pathways and differentially expressed proteins globally by removing CB in Tg mice using mass spectrometry and antibody microarray. Immunohistochemistry showed that CBKOTg mice had significant neuronal loss in the subiculum area without changing the magnitude (number) of amyloid β-peptide (Aβ) plaques deposition and elicited significant apoptotic features and mitochondrial dysfunction compared with Tg mice. Moreover, CBKOTg mice reduced levels of phosphorylated mitogen-activated protein kinase (extracellular signal-regulated kinase) 1/2 and cAMP response element-binding protein at Ser-133 and synaptic molecules such as N-methyl-D-aspartate receptor 1 (NMDA receptor 1), NMDA receptor 2A, PSD-95 and synaptophysin in the subiculum compared with Tg mice. Importantly, this is the first experimental evidence that removal of CB from amyloid precursor protein/presenilin transgenic mice aggravates AD pathogenesis, suggesting that CB has a critical role in AD pathogenesis.

Determination of selected reaction monitoring peptide transitions via multiplexed product-ion scan modes

RATIONALE

Although in silico prediction of selected reaction monitoring (SRM) peptide transitions is the most commonly used approach in quantitative proteomics, systematically detectable peptide transitions selected from actual experimental data are desirable. Here, we demonstrated the use of two triple quadrupole mass spectrometry (QqQ-MS) operation modes to identify reliable SRM peptide transitions of target peptides selected from a shotgun proteomic linear ion-trap mass spectrometry (LIT-MS) profiling dataset.

METHODS

Transition ions (Q1 and Q3 ions) of target peptides were selected from the LIT MS/MS spectra. We performed multiplexed SRM blindly for the selected transition ions of target peptides using QqQ-MS and selected peptide transitions for which the chromatographically aligned and correlated ion intensities to the corresponding fragment ions appeared in the LIT MS/MS spectra. The identities of the peptides were further confirmed by MS/MS spectra acquired via SRM-triggered MS/MS on QqQ-MS.

RESULTS

Despite the different MS platforms, we observed similar MS/MS patterns and relative ion abundance using both LIT-MS and QqQ-MS. Therefore, we were able to determine peptide transitions based on matching the chromatographic peak areas of all the selected Q3 ions of target peptides by the order of the corresponding ion intensities in the LIT MS/MS spectra. This approach demonstrated an efficient method to determine SRM peptide transitions, particularly when the target proteins are in low abundance and are therefore not easily detected by the QqQ full MS/MS scan mode. We employed this approach to determine the SRM peptide transitions of mitochondrial oxidative phosphorylation (OXPHOS) proteins involved in mitochondrial ATP synthesis.

CONCLUSIONS

The multiplexed product-ion scan mode using QqQ-MS generates systematically detectable peptide transitions in a single liquid chromatography/MS run, in which we were able to identify SRM peptides that represent known target proteins in complex biological samples. The method presented here is easy to implement and has high-throughput capabilities as a result of the short analysis time. It is therefore well suited for the design of optimal SRM experiments.

Validation of international consensus guidelines for the resection of branch duct-type intraductal papillary mucinous neoplasms

Background

Classifications of intraductal papillary mucinous neoplasm (IPMN) remain ambiguous, especially for the mixed type. Factors predicting malignancy remain unclear. The aim of this study was to evaluate the usefulness of factors predicting malignancy in the new international consensus guidelines for resection of branch duct-type (BD)-IPMN and to compare them with those in the previous version.

Methods

A prospectively collected database of patients with biopsy-proven BD-IPMN was analysed to compare factors between the first and second consensus guidelines, particularly as predictors of malignancy.

Results

Of 350 patients with BD-IPMN, sensitivity (0·724) and balanced accuracy (0·751) of the second guidelines were superior to those (0·639 and 0·730) in the first version at the expense of slightly reduced specificity (0·779 versus 0·822 for the first version) by random forest models. Multiple logistic regression analysis showed that main pancreatic duct dilatation greater than 5 mm (hazard ratio (HR) 4·54, 95 per cent confidence interval 2·45 to 8·41; P &lt; 0·001), mural nodules (HR 6·27, 3·27 to 12·01; P &lt; 0·001) and carbohydrate antigen 19–9 level above 37 units/ml (HR 4·03, 1·83 to 8·90; P = 0·001) were independent predictors of BD-IPMN malignancy.

Conclusion

The new consensus guidelines provide better sensitivity, performance of factors predicting malignancy, and balanced accuracy in the diagnosis of BD-IPMN malignancy. Size alone was limited in predicting malignancy. Variability in clinical significance of the individual factors associated with a risk of malignancy indicates the need for a tailored approach in the management of patients with BD-IPMN.

Phosphoproteomic analysis identifies activated MET-axis PI3K/AKT and MAPK/ERK in lapatinib-resistant cancer cell line

Lapatinib, a dual inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) tyrosine kinases, has shown promising results as a growth inhibitor of HER2-positive cancer cells in vitro. However, similar to other EGFR-targeting drugs, acquired resistance to lapatinib by HER2-positive cancer cells remains a major clinical challenge. To elucidate resistance mechanisms to EGFR/HER2-targeting agents, we performed a systematic quantitative comparison of the phosphoproteome of lapatinib-resistant (LR) human gastric cancer cells (SNU216-LR) versus parental cells (SNU216) using a titanium dioxide (TiO2) phosphopeptide enrichment method and analysis with a Q-Exactive hybrid quadrupole-Orbitrap mass spectrometer. Biological network analysis of differentially expressed phosphoproteins revealed apparent constitutive activation of the MET-axis phosphatidylinositide 3-kinase (PI3K)/α-serine/threonine-protein kinase (AKT) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathways in SNU216-LR. Inhibition of the PI3K/AKT and MAPK/ERK signaling pathways in SNU216-LR also leads to cell cycle arrest, confirming the biological network analysis. Lapatinib sensitivity was restored when cells were treated with several molecular targeting agents in combination with lapatinib. Thus, by integrating phosphoproteomic data, protein networks and effects of signaling pathway modulation on cell proliferation, we found that SNU216-LR maintains constitutive activation of the PI3K/AKT and MAPK/ERK pathways in a MET-dependent manner. These findings suggest that pathway activation is a key compensatory intracellular phospho-signaling event that may govern gastric cancer cell resistance to drug treatment.

Synapsin-1 and tau reciprocal O-GlcNAcylation and phosphorylation sites in mouse brain synaptosomes

O-linked N-acetylglucosamine (O-GlcNAc) represents a key regulatory post-translational modification (PTM) that is reversible and often reciprocal with phosphorylation of serine and threonine at the same or nearby residues. Although recent technical advances in O-GlcNAc site-mapping methods combined with mass spectrometry (MS) techniques have facilitated study of the fundamental roles of O-GlcNAcylation in cellular processes, an efficient technique for examining the dynamic, reciprocal relationships between O-GlcNAcylation and phosphorylation is needed to provide greater insights into the regulatory functions of O-GlcNAcylation. Here, we describe a strategy for selectively identifying both O-GlcNAc- and phospho-modified sites. This strategy involves metal affinity separation of O-GlcNAcylated and phosphorylated peptides, β-elimination of O-GlcNAcyl or phosphoryl functional groups from the separated peptides followed by dithiothreitol (DTT) conjugation (BEMAD), affinity purification of DTT-conjugated peptides using thiol affinity chromatography, and identification of formerly O-GlcNAcylated or phosphorylated peptides by MS. The combined metal affinity separation and BEMAD approach allows selective enrichment of O-GlcNAcylated peptides over phosphorylated counterparts. Using this approach with mouse brain synaptosomes, we identified the serine residue at 605 of the synapsin-1 peptide, ⁶⁰³QASQAGPGPR⁶¹², and the serine residue at 692 of the tau peptide, ⁶⁸⁸SPVVSGDTSPR⁶⁹⁸, which were found to be potential reciprocal O-GlcNAcylation and phosphorylation sites. These results demonstrate that our strategy enables mapping of the reciprocal site occupancy of O-GlcNAcylation and phosphorylation of proteins, which permits the assessment of cross-talk between these two PTMs and their regulatory roles.

Effects of pancreatectomy on nutritional state, pancreatic function and quality of life

Background

There are concerns about the extent of impaired endocrine and exocrine pancreatic function and poor quality of life (QoL) after pancreatectomy, but there is little information from large prospective follow-up studies.

Methods

Consecutive patients undergoing pancreaticoduodenectomy or distal pancreatectomy between 2007 and 2011 were included. Relative bodyweight (RBW), triceps skinfold thickness (TSFT), serum protein, albumin, transferrin, fasting blood glucose, postprandial 2-h glucose (PP2), glycosylated haemoglobin A1c and stool elastase measurements, and European Organization for Research and Treatment of Cancer QLQ-C30 questionnaires were collected serially for 1 year.

Results

Some 136 patients undergoing pancreatic resection completed the study. RBW and TSFT recovered to over 90 per cent of the preoperative value by 12 months, whereas transferrin, albumin and protein had returned to preoperative levels by 3 months. Diabetes mellitus, impaired fasting glucose or raised PP2 was present in 42 of 76 patients at 6 months and 36 of 76 at 12 months. Although steatorrhoea and diarrhoea had mainly resolved by 3 months, stool elastase level decreased after operation and showed no recovery. Nutritional status, pancreatic endocrine function and QoL returned to preoperative levels in 63 (46·3 per cent), 72 (52·9 per cent) and 77 (56·6 per cent) of 136 patients within 6 months of pancreatectomy. Multivariable analysis revealed that age 60 years or more, operation type, chronic pancreatitis and malignant disease had a significant impact on nutritional index, pancreatic function and QoL.

Conclusion

About half of all patients can expect recovery from pancreatectomy after 6 months, but those with risk factors need more careful follow-up and supportive management.

Proteomic analysis reveals that CD147/EMMPRIN confers chemoresistance in cancer stem cell-like cells

Cancer stem cells (CSCs) are a subpopulation of tumor cells that can self-renew, metastasize, and promote cancer recurrence. A comprehensive characterization of the CSC proteome has been hampered due to their scarcity and rapid differentiation. Here, we present a systematic analysis of the cell-surface proteome using a CSC-like cell line derived from MDA-MB453 breast cancer cells, which exhibited a CD44(+) /CD24(-) (where CD is cluster of differentiation) phenotype and chemoresistance. We identified differentially expressed proteins in CSC-like cells, including upregulated plasma membrane proteins such as CD44, CD133, epidermal growth factor receptor (EGFR), CD147, cadherin 1, integrins, and catenin (cadherin-associated protein), beta 1 (CTNNB1), using an in-situ biotinylation approach followed by MS analysis. We examined the role of CD147 in the promotion of CSC growth and survival, and demonstrated that inhibition of CD147 with a monoclonal antibody induced significant inhibition of cell growth. siRNA-mediated silencing of CD147 gene expression restored the sensitivity of CSC-like cells to 5-fluorouracil (5-FU), along with decreasing the expression of thymidylate synthase, p-AKT, and β-catenin, while increasing the expression of p-glycogen synthase kinase (GSK)3β. Increased CD147 expression in the CSC-like cells, as seen by proteomic analysis, and the functional consequences of CD147 overexpression in CSC-like cells suggest that CD147 may be one of the critical cell-surface proteins involved in promoting chemoresistance and survival in CSCs.

Abstract P3-12-05: Clinical features and outcomes of leptomeningeal metastasis in patients with breast cancer: a single center experience

Background: Leptomeningeal metastasis (LM) is one of the major problems in managing metastatic breast cancer because of LM typically carries a devastating prognosis and often represents a terminal event. We analyzed the clinical features and outcomes of LM in patients with breast cancer.

Methods: We retrospectively reviewed the medical records of patients who were diagnosed with LM from breast cancer between 2002 and 2012 at Asan Medical Center.

Results: Of the 95 LM patients by cytologically proven (n = 81) or radiologically diagnosed (n = 14), 57 (60%) had an ECOG performance status (PS) ≥ 3, and the median age was 47 years (range, 26–72 years). The patients were diagnosed with LM after a median of 10.3 months (95% CI, 5.5–15.0 months) from the time of diagnosis of metastatic breast cancer. LM was present in 2 patients at the time of initial diagnosis. Twenty-three patients (24.2%) had isolated CNS metastasis, and 6 (6.3%) had only LM without any detectable metastasis sites. At the time of diagnosis of LM, 46 patients (48.4%) presented with coincidental failure of systemic disease control. Seventy-eight patients (82.1%) underwent intrathecal chemotherapy (methotrexate; n=78, thiotepa; n=11), resulting in one-third of cytologic negative conversion (n = 26), and 41 (43.2%) received systemic chemotherapy. The overall median survival time was 3.3 months (95% CI, 2.5–4.2 months) and 7.8% of the patients survived for more than 1 year. Overall survival tended to be better in patients who achieved cytologic negative conversion to intrathecal chemotherapy than those did not (median 4.5 months versus 3.2 months, P = 0.241). Overall survival was not different according to subtypes; hormone receptor (+), HER2 (+), and triple negative (median 3.6 months, 3.3 months, and 3.2 months, P = 0.937). Multivariate analysis demonstrated that ECOG PS ≥ 3 (HR = 2.09, 95% CI 1.21–3.58, P = 0.007), coincidental failure of systemic disease control at LM (HR = 3.01, 95% CI 1.76–5.15, P &lt; 0.001), and systemic chemotherapy after LM (HR = 0.40, 95% CI 0.24–0.68, P = 0.001) were independent factors associated with survival.

Conclusions: The prognosis for patients with LM from breast cancer was still poor. Systemic chemotherapy in addition to intrathecal chemotherapy might confer a survival benefit, even after the detection of LM.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-12-05.

Changing trend in bile microbiology and antibiotic susceptibilities: over 12 years of experience

PURPOSE

Rapidly changing medical environments may have changed the microbiology of infected bile. The aim of our study was to identify the changing trends in microorganisms in biliary infections and examine their susceptibilities against currently recommended antibiotics.

METHODS

Bile cultures taken between 1998 and 2010 at Seoul National University Hospital, a tertiary medical center, were retrospectively reviewed. From 1,403 patients, 3,425 microorganisms were isolated from 2,217 cultures. The cultures were then tested to determine the types of microorganisms and their antibiotic susceptibility.

RESULTS

The five most frequently isolated microorganisms were Enterococcus (22.7 %) followed by Escherichia (13.2 %), Pseudomonas (10.9 %), Klebsiella (10.3 %), and Enterobacter (7.2 %). The trend in annual incidence indicated a growing emergence of Enterococcus (P < 0.001). Among Enterococcus, E. faecium acquired a dominant position (50.6 %), showing an increasing trend over the study period (P = 0.026). The incidence of vancomycin-resistant Enterococcus also showed an increasing trend (P < 0.001). Many of the commonly used antibiotics provided inadequate coverage for the more frequently encountered microorganisms. Multiple regression revealed that benign causes of obstruction and non-operative treatment harbor an increased risk for enterococcal growth (P = 0.001 and P = 0.027, respectively).

CONCLUSIONS

In contrast to earlier reports, we found that Enterococcus has emerged as the most frequently isolated microorganism from bile. The importance of enterococcal infection should be recognized, and currently recommended antibiotics need to be re-evaluated since in our bile cultures most provided inadequate coverage for the more frequently encountered microorganisms. The changes in the trends of microorganisms isolated from bile should be considered in cases where patients present with biliary obstruction.

Risk factors for osteoporosis in long-term survivors of intracranial germ cell tumors

SUMMARY

We measured bone mineral densities in 28 intracranial germ cell tumor long-term survivors. There was the high prevalence of osteoporosis and osteopenia, 25.0% and 42.9%, respectively, and three additional risk factors, male sex, a low lean mass, and adult growth hormone replacement, were identified.

INTRODUCTION

Intracranial germ cell tumor long-term survivors (iGCTLS) have many risk factors for osteoporosis, including irradiation from cancer therapy and multiple hormone deficiencies. However, no study of bone mineral density (BMD) has been conducted in iGCTLS because these tumors are rare. The aims of this study were to evaluate the prevalence of osteoporosis and to identify risk factors associated with reduced bone mass in iGCTLS.

METHODS

We evaluated BMD and body composition of 28 iGCTLS (10.9 ± 5.2 years after cancer treatment; 13 males) using dual-energy X-ray absorptiometry. To determine risk factors, we analyzed the medical history, including the nature of the tumor, treatment modality, endocrine status, hormone replacement therapy, lifestyle, and biochemical parameters.

RESULTS

Twenty-five percent of iGCTLS were diagnosed with osteoporosis and 42.9% with osteopenia. Most males (92.3%) had low BMD. Lean mass (LM) was positively correlated with BMD in all regions of interest, and the starting age of adult growth hormone (GH) replacement was negatively correlated with the BMD Z-score at the femur neck. In logistic regression analysis, male sex and low LM were related to low BMD.

CONCLUSIONS

The iGCTLS had a high prevalence of low BMD. We found that male sex, low LM, and delayed start of adult GH replacement were risk factors for osteoporosis. Therefore, the BMD of all iGCTLS should be evaluated, and if it is low, proper management should be started early.

Heterodimerization of glycosylated insulin-like growth factor-1 receptors and insulin receptors in cancer cells sensitive to anti-IGF1R antibody

BACKGROUND

Identification of predictive biomarkers is essential for the successful development of targeted therapy. Insulin-like growth factor 1 receptor (IGF1R) has been examined as a potential therapeutic target for various cancers. However, recent clinical trials showed that anti-IGF1R antibody and chemotherapy are not effective for treating lung cancer.

METHODOLOGY/PRINCIPAL FINDINGS

In order to define biomarkers for predicting successful IGF1R targeted therapy, we evaluated the anti-proliferation effect of figitumumab (CP-751,871), a humanized anti-IGF1R antibody, against nine gastric and eight hepatocellular cancer cell lines. Out of 17 cancer cell lines, figitumumab effectively inhibited the growth of three cell lines (SNU719, HepG2, and SNU368), decreased p-AKT and p-STAT3 levels, and induced G 1 arrest in a dose-dependent manner. Interestingly, these cells showed co-overexpression and altered mobility of the IGF1R and insulin receptor (IR). Immunoprecipitaion (IP) assays and ELISA confirmed the presence of IGF1R/IR heterodimeric receptors in figitumumab-sensitive cells. Treatment with figitumumab led to the dissociation of IGF1-dependent heterodimeric receptors and inhibited tumor growth with decreased levels of heterodimeric receptors in a mouse xenograft model. We next found that both IGF1R and IR were N-linked glyosylated in figitumumab-sensitive cells. In particular, mass spectrometry showed that IGF1R had N-linked glycans at N913 in three figitumumab-sensitive cell lines. We observed that an absence of N-linked glycosylation at N913 led to a lack of membranous localization of IGF1R and figitumumab insensitivity.

CONCLUSION AND SIGNIFICANCE

The data suggest that the level of N-linked glycosylated IGF1R/IR heterodimeric receptor is highly associated with sensitivity to anti-IGF1R antibody in cancer cells.

In-vitro study on haemodiluted blood flow in a sinusoidal microstenosis

In-vitro experiments were carried out to investigate the haemodynamic and haemorheological behaviours of haemodiluted blood flow through a microstenosis using a micro-particle image velocimetry (PIV) technique. The micro-PIV system employed in this study consisted of a two-head neodymium:yttrium-aluminium-garnet (Nd:YAG) laser, a cooled charge-coupled device camera, and a delay generator. To simulate blood flow in a stenosed vascular vessel, a polydimethylsiloxane (PDMS) microchannel with a sinusoidal throat of 80 per cent severity was employed. The width and depth of the microchannel were 100 microm and 50 microm, respectively. To compare the flow characteristics in the microstenosis, the same experiments were repeated in a straight microchannel under the same flow conditions. Using a syringe pump, human blood with 5 per cent haematocrit was supplied into the microstenosis channel. The flow characteristics and transport of blood cells through the microstenosis were investigated with various flowrates. The mean velocity fields were nearly symmetric with respect to the channel centreline. In the contraction section, the oncoming blood flow was accelerated rapidly, and the maximum velocity at the throat was almost 4.99 times faster than that of the straight microchannel without stenosis. In the diffusion section, the blood cells show rolling, deformation, twisting, and tumbling motion due to the flow-choking characteristics at the stenotic region. The results from this study will provide useful basic data for comparison with those obtained by clinical researchers.

A Retrospective Study on Intracerebral Haemorrhage Reduction by Mri versus Ct in Intravenous Thrombolysis for Acute Ischaemic Stroke

Introduction

Multimodal MRI may be an effective tool for selecting suitable acute ischaemic stroke patients for thrombolysis, reducing the risk of haemorrhage. In this study, we demonstrated the usefulness of our central alerting system to reduce door-to-needle time for thrombolysis following MRI. This system allowed timely intervention and reduced the rate of symptomatic haemorrhage.

Methods

We reviewed the records of 73 patients with hyperacute ischaemic stroke who received intravenous (IV) tissue plasminogen activator (t-PA) between January 2006 and December 2007 following the adoption of a central stroke alerting system in our hospital.

Results

Of the 73 patients who received IV t-PA, 44 were based on CT and 29 on MRI findings. The door-to-needle time was 10 minutes longer for the MRI group (49.9±23.2 min) compared to the CT group (39.6±19.7 min) but it was still within the recommended 60 minutes time frame. On the other hand, the rate of symptomatic haemorrhage was lower, though insignificantly, in the MRI group (0%) compared to the CT group (13.6%) (p=0.08).

Conclusions

In this study, we demonstrated that the combination of diagnostic MRI and a central alerting system might reduce the rate of symptomatic haemorrhage without compromising the door-to-needle time.

Presenilin enhancer-2 (PSENEN), a component of the gamma-secretase complex, is involved in adipocyte differentiation

This study was conducted to identify genes expressed during adipocyte differentiation of bovine intramuscular fibroblast-like cells using differential display reverse-transcriptase polymerase chain reaction. The presenilin enhancer-2 (PSENEN) gene was found to be down-regulated during adipocyte differentiation of bovine intramuscular fibroblast-like cells. The ectopic expression of bovine PSENEN in 3T3-L1 reduced adipogenesis and the inhibition of endogenous PSENEN by siRNA induced adipogenesis on d 4 of adipocyte differentiation of 3T3-L1 cells. Interestingly, the expression of gamma-secretase complex gene-related Notch signaling was decreased at d 2 and d 4 during adipocyte differentiation. In addition, expression of the Notch-signaling genes (Notch-1, Hes-1, Pref-1, adipsin) was regulated during adipocyte differentiation by regulation of PSENEN expression. These results suggest that PSENEN plays an important role in adipocyte differentiation and that Notch signaling is involved in adipogenesis.

Development of functional human immune system with the transplantations of human fetal liver/thymus tissues and expanded hematopoietic stem cells in RAG2-/-gamma(c)-/- MICE

BACKGROUND

There is an increasing need for suitable animal models for the study of the human immune system and disease. The purpose of this study was to develop a practical in vivo model of human immune cell repopulation using ex vivo expanded human fetal liver-derived CD34(+) hematopoietic stem cells and subrenally coimplanted fetal liver/thymus tissues.

METHODS

Freshly isolated fetal liver-derived CD34(+) hematopoietic stem cells were frozen until injected and ex vivo expanded with various cytokines for 7 days. After fetal liver/thymus tissues were subrenally coimplanted into preirradiated Rag2(-/-)gamma(c)(-/-) mice, frozen and ex vivo expanded CD34(+) cells were injected intravenously. The peripheral blood of the mice was monitored for the detection of human cell engraftment using flow cytometry. Then we confirmed human T-cell function by in vitro function assays.

RESULTS

After fetal liver/thymus tissues were coimplanted into the irradiated Rag2(-/-)gamma(c)(-/-) mice, with frozen and ex vivo expanded CD34(+) hematopoietic stem cells, human cell engraftments were determined using hCD45 and multilineage markers. The cultured cells with the cytokine combination of stem cell factor, thrombopoietin, Flk2/Flk3 ligand (FL), and interleukin-3 showed stable and long-term engraftment compared to other combinations. The ex vivo expanded human fetal liver-derived CD34(+) hematopoietic stem cells, under our culture conditions, accomplished a large volume of expanded cells that were sustained, demonstrating self-renewal of the evaluated markers, which may have indicated long- term repopulation activity.

CONCLUSION

The results of this study demonstrated a practical mouse model of expanded human immune cells especially T cells in Rag2(-/-)gamma(c)(-/-) mice.

Oncocytoma of the spinal cord causing paraplegia – a case report

STUDY DESIGN

Case report.

OBJECTIVES

To describe a rare case of oncocytoma arising from the spinal cord in a 40-year old woman.

SETTING

Republic of Korea.

METHODS

The patient's history, physical examination, radiological and pathological findings were reviewed.

RESULTS

A 40-year-old woman presented with 3-month history of low back pain. Magnetic resonance imaging revealed an intradural extramedullary mass located between L1 and L4. She refused any surgical treatment and so was discharged. At 10 days after discharge, an emergency operation was performed because of sudden paralysis in both lower extremities. The confirmed diagnosis is oncocytoma. At 4 months after surgery, the patient failed to obtain neurological recovery from complete paraplegia.

CONCLUSIONS

Since the progression of an intradural extramedullary mass that shows minor neurological symptoms can lead to complete paraplegia in a short time, close observation and early surgical decompression are necessary.

Viral infection following kidney transplantation: long-term follow-up in a single center

INTRODUCTION

Viral infections are a leading cause of posttransplantation morbidity and mortality. The use of more potent immunosuppressive agents is responsible in part for the increasing incidence of some viral infections. This study summarized our experience with viral infections in 561 kidney transplant recipients.

METHODS

The spectrum of viral infections in 561 consecutive kidney transplant recipients was examined retrospectively from November 1982 to November 2002.

RESULTS

During a mean follow-up of 64.0 months, 193 virus infections in 156 of 561 kidney transplant recipients were recorded, an incidence of 34.2%. The most common viruses were cytomegalovirus (36.3%), varicella zoster virus (29.0%), herpes simplex virus (23.8%), BK virus (4.7%), hepatitis B virus (3.6%), and hepatitis C virus (2.6%). Among the CMV infections, 77.1% developed subclinical CMV infection and 22.9% had CMV disease. Generalized herpes zoster infection occurred in three cases and chicken pox in six cases. During a mean follow-up of 64.0 months, two of 159 patients died of CMV pneumonia.

CONCLUSION

Viral infections among the kidney transplant recipients continue to be a major problem despite significant progress in understanding the pathogenesis of viral infection and the advent of antiviral therapy.

BK virus infection in kidney transplant recipients

INTRODUCTION

Nephropathy associated with the polyomavirus type BK virus (BKV) has emerged as a cause of allograft failure linked to immunosuppressive regimens containing tacrolimus or mycophenolate mofetil (MMF). The outcome in BKV nephropathy is generally unfavorable, namely 50% of patients lose graft function. We herein report nine cases of BKV nephropathy after kidney transplantation.

METHODS

From October 1998 to May 2003, 138 of 169 consecutive kidney transplant patients received tacrolimus-based immunosuppression, and 31 received cyclosporine-based immunosuppression. Additionally, 88.2% of the patients received mycophenolate mofetil (MMF). The diagnosis of BK infection was made by the presence of decoy cells in the urine and by allograft biopsy.

RESULTS

There were nine cases of BKV nephropathy in kidney transplant recipients, an incidence of 5.3%. All patients with BKV nephropathy received tacrolimus, MMF, and steroids. The median time to diagnosis of BKV infection was 7.8 months after transplantation. All patients experienced an elevated serum creatinine, which stabilized or decreased in seven patients with altered or decreased immunosuppression. After a mean follow-up of 11.1 months, 2 (22.2%) of nine patients lost the graft.

CONCLUSION

Because BKV nephropathy is a rare but serious complication after kidney transplantation, it should be included in the clinical differential of transplant dysfunction. In the absence of documented antiviral treatment, early diagnosis and judicious use of immunosuppressive agents is indicated to minimize the occurrence of BKV infection.

A case of fungal sepsis due to aspergillus spondylitis followed by cytomegalovirus infection in a renal transplant recipient

Although advances in immunosuppressive therapy have led to increased survival of renal transplant recipients, there are greater risks of developing infectious complications. Because of its rarity and the lack of medical awareness, aspergillus spondylitis is often misdiagnosed as tuberculous spondylitis, especially in its early stages. We report a case of aspergillus spondylitis in a renal transplant followed by cytomegalovirus (CMV) retinitis.

CASE

A 59-year-old woman was admitted due to general weakness and abdominal discomfort. She had undergone renal transplantation 3 years previously. One month before admission, she was diagnosed with CMV retinitis and treated with IV ganciclovir. On admission, she suffered from lower abdominal pain. Colonoscopy revealed multiple circular or patchy ulcers with surrounding severe mucosal edema in the sigmoid colon findings consistent with intestinal tuberculosis. On hospital day 30, she complained of lower extremity paresthesia and weakness. An MRI of the spine revealed a well-demarcated paraspinal mass around the L2-4 body; tuberculous spondylitis was initially considered. But despite antituberculosis medication, the patient progressed to spastic paraparesis and sensory changes in both lower legs, requiring urgent surgical decompression. At hospital day 60, she suffered persistent fever and developed thrombocytopenia. Wound discharge continued and paraparesis became denser. A CT of the spine showed progression of the paraspinal abscess from the L2 body to the iliac crest. CT-guided psoas muscle drainage was performed. Fungal culture showed Aspergillus species. Despite antifungal therapy, the patient died after a prolonged hospital stay due to fungal sepsis and septic shock from aspergillosis.

A case of primary cutaneous aspergillosis in a renal transplant recipient

Opportunistic fungal infections are life-threatening complications which are a major cause of morbidity and mortality in immunocompromized hosts such as those who have undergone organ transplantation. Aspergillosis comprises a spectrum of disease caused by a ubiquitous saprophytic mold. Invasive aspergillus is a serious life-threatening complication in immunocompromised hosts. Primary cutaneous aspergillosis occurs relatively less frequently and is poorly characterized. We report a case of cutaneous aspergillosis in a 51-year-old renal transplant recipient, which was successfully treated with local excision and concomitant antifungal therapy.

CASE

A 51-year-old male renal transplant recipient presented with cutaneous nodules on the dorsum of the right hand. He underwent renal transplantation for end-stage renal disease due to adult dominant polycystic kidney disease (ADPKD) 3 years prior. Initially he suffered an acute rejection episode that was treated with steroid pulse and OKT3 therapy. Eventually he was stabilized on a combination of tacrolimus, prednisone, and mycophenolate mofetil. Three years after transplantation, he developed painless multiple (largest one 5 x 3 cm sized) nodules on the dorsum of his right hand. He was afebrile with no systemic symptoms. A skin biopsy showed a dense solid infiltration of giant cells, histiocytes, and lymphoplasma cells admixed with intra- and extracellular fungal hyphae and spores. The hyphae were septate and acute angle branching, which was consistent with aspergillosis. Oral itraconazole 200 mg/d for 5 weeks was ineffective. Treatment with liposomal amphotericin B for 4 weeks was initiated and MMF was discontinued. The medication was well tolerated with no hepatotoxic effects. Although new lesions did not appear, existing ones did not significantly improve after 4 weeks of treatment. Therefore, most lesions were excised surgically and liposomal amphotericin B continued for 2 weeks followed by treatment with oral fluconazole for 2 months. Ten moths later there was no evidence of recurrence.