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1.  Direct targeting of MEK1/2 and RSK2 by silybin induces cell cycle arrest and inhibits melanoma cell growth 
Abnormal functioning of multiple gene products underlies the neoplastic transformation of cells. Thus, chemopreventive and/or chemotherapeutic agents with multigene targets hold promise in the development of effective anticancer drugs. Silybin, a component of milk thistle, is a natural anticancer agent. In the present study, we investigated the effect of silybin on melanoma cell growth and elucidated its molecular targets. Our study revealed that silybin attenuated the growth of melanoma xenograft tumors in nude mice. Silybin inhibited the kinase activity of mitogen-activated protein kinase kinase (MEK)-1/2 and ribosomal S6 kinase (RSK)-2 in melanoma cells. The direct binding of silybin with MEK1/2 and RSK2 was explored using a computational docking model. Treatment of melanoma cells with silybin attenuated the phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 and RSK2, which are regulated by the upstream kinases MEK1/2. The blockade of MEK1/2-ERK1/2-RSK2 signaling by silybin resulted in a reduced activation of nuclear factor-kappaB, activator protein-1 and signal transducer and activator of transcription-3, which are transcriptional regulators of a variety of proliferative genes in melanomas. Silybin, by blocking the activation of these transcription factors, induced cell cycle arrest at the G1 phase and inhibited melanoma cell growth in vitro and in vivo. Taken together, silybin suppresses melanoma growth by directly targeting MEK- and RSK-mediated signaling pathways.
PMCID: PMC3644346  PMID: 23447564
Silybin; BRAF/MEK/ERK/RSK signaling pathway; melanoma
2.  Clinicopathologic significance of expression of nuclear factor-κB RelA and its target gene products in gastric cancer patients 
AIM: To assess the prognostic significance of nuclear factor-κB (NF-κB) and its target genes in gastric cancer.
METHODS: The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using monoclonal antibodies against NF-κB RelA. Preoperative serum levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) were assessed via enzyme-linked immuno-sorbent assay. C-reactive protein (CRP) and serum amyloid A (SAA) were measured via immunotrubidimetry.
RESULTS: Positive rate of NF-κB RelA was 42.6%. NF-κB RelA expression in tumor tissues was also related to serum levels of IL-6 (P = 0.044) and CRP (P = 0.010). IL-6, SAA, CRP were related to depth of invasion, VEGF and SAA were correlated with lymph node metastasis. IL-6, VEGF, SAA and CRP were related to the stage. Univariate analysis demonstrated that immunostaining of NF-κB RelA, levels of IL-6, VEGF, SAA were significantly related with both disease free survival and overall survival (OS). Multivariate analysis verified that NF-κB RelA [hazard ratio (HR): 3.40, P = 0.024] and SAA (HR: 3.39, P = 0.045) were independently associated with OS.
CONCLUSION: Increased expression of NF-κB RelA and high levels of serum SAA were associated with poor OS in gastric cancer patients.
PMCID: PMC3442213  PMID: 23002344
Nuclear factor-κB; Vascular endothelial growth factor; Interleukin-6; C-reactive protein; Serum amyloid A; Stomach; Carcinoma
3.  Clinical significance of anti-mitochondrial antibodies in a patient with chronic graft-versus-host disease following hematopoietic stem cell transplantation 
The Korean Journal of Hematology  2011;46(3):200-202.
Recent studies indicate that patients with chronic graft-versus-host disease (GVHD) are not expected to show positivity for anti-mitochondrial antibody (AMA), which is a specific disease marker for primary biliary cirrhosis (PBC). A differential diagnosis between PBC and hepatic involvement of GVHD based on clinical manifestations and pathologic study is difficult because both diseases show similar results. Therefore, the presence of AMA may be important for distinguishing each disease. Here, we report a case of hepatic involvement of chronic GVHD with positive AMA, in which the pathologic findings and initial presentation of clinical findings were compatible with both PBC and chronic GVHD.
PMCID: PMC3208205  PMID: 22065977
Autoantibody; Anti-mitochondrial antibody; Chronic graft-versus-host disease; Hematopoietic stem cell transplantation
4.  Fludarabine-based myeloablative regimen as pretransplant conditioning therapy in adult acute leukemia/myelodysplastic syndrome: comparison with oral or intravenous busulfan with cyclophosphamide 
The Korean Journal of Hematology  2010;45(2):102-108.
A combination of busulfan (Bu) and cyclophosphamide (Cy) has been used as a standard myeloablative regimen for allogeneic hematopoietic stem cell transplantation (HSCT). Recent studies postulate that fludarabine (Flu) is a less toxic substitute for Cy.
Forty-two patients who were diagnosed with acute leukemia or myelodysplastic syndrome and received BuFlu (n=17) or BuCy (n=25) from August, 1999 to July, 2009 at Dong-A University Medical Center were retrospectively analyzed.
The median follow-up duration was 39.75 months. The BuFlu group showed a lower incidence of mucositis (P=0.005), but there was no significant intergroup difference in the time of engraftment, nausea/vomiting, acute/chronic graft-versus-host disease, hepatic veno-occlusive disease, or hemorrhagic cystitis. Moreover, the 2 groups showed no significant difference in the cumulative risk of relapse, event-free survival, or overall survival.
BuFlu administration can be employed as a preparative regimen for allogeneic HSCT and shows efficacy and transplant-adverse effects comparable to those of BuCy. However, randomized prospective studies in more patients are warranted.
PMCID: PMC2983027  PMID: 21120188
Myeloablative regimen; Allogeneic hematopoietic stem cell transplantation; Fludarabine; Busulfan
5.  A case of subdural hematoma in patient with chronic myeloid leukemia treated with high-dose imatinib mesylate 
Imatinib mesylate (IM) is used to treat a wide range of diseases, including Philadelphia chromosome-positive chronic myeloid leukemia (CML), on account of its high tolerability and low incidence of minor adverse events. Hemorrhage is thought to be a rare complication of IM. Recently, IM has been associated with reduced α2-plasmin inhibitor and platelet dysfunction. We report here the case of a 33-year-old female patient with CML who experienced subdural hematoma after an incremental increase in IM dosage due to a loss of complete molecular response. This case indicates that physicians should be alert to this atypical cause of headache in patients taking high-dose IM.
PMCID: PMC2983009  PMID: 21120168
Chronic myeloid leukemia; Imatinib mesylate; Subdural hematoma
6.  Gastric leptomeningeal carcinomatosis: Multi-center retrospective analysis of 54 cases 
AIM: To identify the clinical features and outcomes of infrequently reported leptomeningeal carcinomatosis (LMC) of gastric cancer.
METHODS: We analyzed 54 cases of cytologically confirmed gastric LMC at four institutions from 1994 to 2007.
RESULTS: The male-to-female ratio was 32:22, and the patients ranged in age from 28 to 78 years (median, 48.5 years). The majority of patients had advanced disease at initial diagnosis of gastric cancer. The clinical or pathologic tumor, node and metastasis stage of the primary gastric cancer was IV in 38 patients (70%). The median interval from diagnosis of the primary malignancy to the diagnosis of LMC was 6.3 mo, ranging between 0 and 73.1 mo. Of the initial endoscopic findings for the 45 available patients, 23 (51%) of the patients were Bormann type III and 15 (33%) patients were Bormann type IV. Pathologically, 94% of cases proved to be poorly differentiated adenocarcinomas. Signet ring cell component was also observed in 40% of patients. Headache (85%) and nausea/vomiting (58%) were the most common presenting symptoms of LMC. A gadolinium-enhanced magnetic resonance imaging was conducted in 51 patients. Leptomeningeal enhancement was noted in 45 cases (82%). Intrathecal (IT) chemotherapy was administered to 36 patients-primarily methotrexate alone (61%), but also in combination with hydrocortisone/± Ara-C (39%). The median number of IT treatments was 7 (range, 1-18). Concomitant radiotherapy was administered to 18 patients, and concomitant chemotherapy to seven patients. Seventeen patients (46%) achieved cytological negative conversion. Median overall survival duration from the diagnosis of LMC was 6.7 wk (95% CI: 4.3-9.1 wk). In the univariate analysis of survival duration, hemoglobin, IT chemotherapy, and cytological negative conversion showed superior survival duration (P = 0.038, P = 0.010, and P = 0.002, respectively). However, in our multivariate analysis, only cytological negative conversion was predictive of relatively longer survival duration (3.6, 6.7 and 14.6 wk, P = 0.030, RR: 0.415, 95% CI: 0.188-0.918).
CONCLUSION: Although these patients had a fatal clinical course, cytologic negative conversion by IT chemotherapy may improve survival.
PMCID: PMC2768889  PMID: 19860003
Carcinomatosis; Gastric cancer; Intrathecal chemotherapy; Leptomeningeal
7.  Bevacizumab plus infusional 5-fluorouracil, leucovorin and irinotecan for advanced colorectal cancer that progressed after oxaliplatin and irinotecan chemotherapy: A pilot study 
AIM: To evaluate the combination of bevacizumab with infusional 5-fluorouracil (5-FU), leucovorin (LV) and irinotecan (FOLFIRI) in patients with advanced colorectal cancer (CRC) pretreated with combination regimens including irinotecan and oxaliplatin.
METHODS: Fourteen patients (median age 56 years) with advanced CRC, all having progressed after oxaliplatin- and irinotecan-based combination chemotherapy, were enrolled in this study. Patients were treated with 2 h infusion of irinotecan 150 mg/m2 on d 1, plus bevacizumab 5 mg/kg iv infusion for 90 min on d 2, and iv injection of LV 20 mg/m2 followed by a bolus of 5-FU 400 mg/m2 and then 22 h continuous infusion of 600 mg/m2 given on two consecutive days every 14 d.
RESULTS: The median number of cycles of chemotherapy was six (range 3-12). The response rate was 28.5%, one patient had a complete response, and three patients had a partial response. Eight patients had stable disease. The median time to progression was 3.9 mo (95% CI 2.0-8.7), and the median overall survival was 10.9 mo (95% CI 9.6-12.1). Grade 3/4 neutropenia occurred in five patients, and two of these developed neutropenic fever. Grade 3 hematuria and hematochezia occurred in one. Grade 2 proteinuria occurred in two patients. However, hypertension, bowel perforation or thromboembolic events did not occur in a total of 90 cycles.
CONCLUSION: Bevacizumab with FOLFIRI is well tolerated and a feasible treatment in patients with heavily treated advanced CRC.
PMCID: PMC4171235  PMID: 18069765
Bevacizumab; Irinotecan; Leucovorin; 5-fluorouracil; Colorectal cancer
8.  Pilot study of postoperative adjuvant chemoradiation for advanced gastric cancer: Adjuvant 5-FU/cisplatin and chemoradiation with capecitabine 
AIM: To evaluate the efficacy and toxicity of postoperative chemoradiation using FP chemotherapy and oral capecitabine during radiation for advanced gastric cancer following curative resection.
METHODS: Thirty-one patients who had underwent a potentially curative resection for Stage III and IV (M0) gastric cancer were enrolled. Therapy consists of one cycle of FP (continuous infusion of 5-FU 1000 mg/m2 on d 1 to 5 and cisplatin 60 mg/m2 on d 1) followed by 4500 cGy (180 cGy/d) with capecitabine (1650 mg/m2 daily throughout radiotherapy). Four wk after completion of the radiotherapy, patients received three additional cycles of FP every three wk. The median follow-up duration was 22.2 mo.
RESULTS: The 3-year disease free and overall survival in this study were 82.7% and 83.4%, respectively. Four patients (12.9%) showed relapse during follow-up. Eight patients did not complete all planned adjuvant therapy. Grade 3/4 toxicities included neutropenia in 50.2%, anemia in 12.9%, thrombocytopenia in 3.2% and nausea/vomiting in 3.2%. Neither grade 3/4 hand foot syndrome nor treatment related febrile neutropenia or death were observed.
CONCLUSION: These preliminary results suggest that this postoperative adjuvant chemoradiation regimen of FP before and after capecitabine and concurrent radiotherapy appears well tolerated and offers a comparable toxicity profile to the chemoradiation regimen utilized in INT-0116. This treatment modality allowed successful loco-regional control rate and 3-year overall survival.
PMCID: PMC4066094  PMID: 16489675
Gastric cancer; Postoperative; Adjuvant chemotherapy; Chemoradiation
9.  Dynamic Growth and Shrinkage Govern the pH Dependence of RecA Filament Stability 
PLoS ONE  2015;10(1):e0115611.
RecA proteins form a long stable filament on a single-stranded DNA and catalyze strand exchange reaction. The stability of RecA filament changes dramatically with pH, yet its detailed mechanism is not known. Here, using a single molecule assay, we determined the binding and dissociation rates of RecA monomers at the filament ends at various pH. The pH-induced rate changes were moderate but occurred in opposite directions for binding and dissociation, resulting in a substantial increase in filament stability in lower pH. The highly charged residues in C-terminal domain do not contribute to the pH dependent stability. The stability enhancement of RecA filament in low pH may help the cell to cope with acidic stress by fine-tuning of the binding and dissociation rates without losing the highly dynamic nature of the filament required for strand exchange.
PMCID: PMC4301630  PMID: 25608006
10.  A Single Amino Acid Mutation (I1012F) of the RNA Polymerase of Marine Viral Hemorrhagic Septicemia Virus Changes In Vitro Virulence to Rainbow Trout Gill Epithelial Cells 
Journal of Virology  2014;88(13):7189-7198.
Viral hemorrhagic septicemia virus (VHSV) is separated into four different genotypes (I to IV) with different sublineages (K. Einer-Jensen, P. Ahrens, R. Forsberg, and N. Lorenzen, J. Gen. Virol. 85:1167–1179, 2004; K. Einer-Jensen, J. Winton, and N. Lorenzen, Vet. Microbiol. 106:167–178, 2005). European marine VHSV strains (of genotypes I to III) are, in general, nonpathogenic or have very low pathogenicity to rainbow trout after a waterborne challenge, and here we also show that genotype IVa is nonpathogenic to trout. Despite several attempts, it has not been possible to link genomic variation to in vivo virulence. In vitro virulence to gill epithelial cells (GECs) has been used as a proxy for in vivo virulence, and here we extend these studies further with the purpose of identifying residues associated with in vitro virulence. Genotype Ia (DK-3592B) and III (NO/650/07) isolates, which are pathogenic to rainbow trout (O. B. Dale, I. Orpetveit, T. M. Lyngstad, S. Kahns, H. F. Skall, N. J. Olesen, and B. H. Dannevig, Dis. Aquat. Organ. 85:93–103, 2009), were compared to two marine strains that are nonpathogenic to trout, genotypes Ib (strain 1p8 [H. F. Mortensen, O. E. Heuer, N. Lorenzen, L. Otte, and N. J. Olesen, Virus Res. 63:95–106, 1999]) and IVa (JF-09). DK-3592 and NO/650/07 were pathogenic to GECs, while marine strains 1p8 and JF-09 were nonpathogenic to GECs. Eight conserved amino acid substitutions contrasting high- and low-virulence strains were identified, and reverse genetics was used in a gain-of-virulence approach based on the JF-09 backbone. Mutations were introduced into the G, NV, and L genes, and seven different virus clones were obtained. For the first time, we show that a single amino acid mutation in conserved region IV of the L protein, I1012F, rendered the virus able to replicate and induce a cytopathic effect in trout GECs. The other six mutated variants remained nonpathogenic.
IMPORTANCE This is the first study to clearly link in vitro virulence of viral hemorrhagic septicemia virus (VHSV) with an amino acid residue in the L protein, a site located in conserved region IV of the L protein. In vitro virulence is documented by induction of cytopathic effects and viability studies of gill epithelial cells, and the observed cellular responses to infection are associated with increased viral replication levels. There are no previous studies addressing the importance of the L protein or the RNA-dependent RNA polymerase for virus virulence in vitro or in vivo. Therefore, the findings reported here should broaden the search for pathogenicity traits in novirhabdoviruses, and there is a possibility that the polymerase participates in defining the host species virulence of various VHSV strains.
PMCID: PMC4054441  PMID: 24719422
11.  Survival Benefit of Zoledronic Acid in Postmenopausal Breast Cancer Patients Receiving Aromatase Inhibitors 
Journal of Breast Cancer  2014;17(4):350-355.
A growing body of evidence indicates that zoledronic acid (ZA) can improve the clinical outcome in patients with breast cancer and low estrogen levels. In the present study, we aimed to investigate the survival benefit of ZA administration in postmenopausal Korean women with breast cancer who were also receiving aromatase inhibitors.
Between January 2004 and December 2010, 235 postmenopausal breast cancer patients undergoing aromatase inhibitor therapy were investigated. All patients were postmenopausal, as confirmed by laboratory tests. Of these patients, 77 received adjuvant upfront ZA for at least 1 year in addition to conventional adjuvant treatment. The remaining 158 patients never received ZA and were treated according to the St. Gallen guidelines.
The baseline characteristics for ZA treatment were not different between the two groups. The median follow-up time was 62 months, and the patients who received ZA in addition to aromatase inhibitors showed a better recurrence-free survival compared to those who received aromatase inhibitors alone (p=0.035). On multivariate analysis, the patients who received ZA showed a better recurrence-free survival independent of the tumor size, nodal status, progesterone receptor, and histological grade. For this model, Harrell c index was 0.743. The hazard ratio of ZA use for recurrence-free survival was 0.12 (95% confidence interval, 0.01-0.99).
Our findings suggest that upfront use of ZA as part of adjuvant treatment can offer a survival benefit to postmenopausal breast cancer patients receiving aromatase inhibitor treatment.
PMCID: PMC4278054  PMID: 25548583
Aromatase inhibitors; Breast neoplasms; Postmenopause; Zoledronic acid
12.  Suppression of Cpn10 Increases Mitochondrial Fission and Dysfunction in Neuroblastoma Cells 
PLoS ONE  2014;9(11):e112130.
To date, several regulatory proteins involved in mitochondrial dynamics have been identified. However, the precise mechanism coordinating these complex processes remains unclear. Mitochondrial chaperones regulate mitochondrial function and structure. Chaperonin 10 (Cpn10) interacts with heat shock protein 60 (HSP60) and functions as a co-chaperone. In this study, we found that down-regulation of Cpn10 highly promoted mitochondrial fragmentation in SK-N-MC and SH-SY5Y neuroblastoma cells. Both genetic and chemical inhibition of Drp1 suppressed the mitochondrial fragmentation induced by Cpn10 reduction. Reactive oxygen species (ROS) generation in 3-NP-treated cells was markedly enhanced by Cpn10 knock down. Depletion of Cpn10 synergistically increased cell death in response to 3-NP treatment. Furthermore, inhibition of Drp1 recovered Cpn10-mediated mitochondrial dysfunction in 3-NP-treated cells. Moreover, an ROS scavenger suppressed cell death mediated by Cpn10 knockdown in 3-NP-treated cells. Taken together, these results showed that down-regulation of Cpn10 increased mitochondrial fragmentation and potentiated 3-NP-mediated mitochondrial dysfunction in neuroblastoma cells.
PMCID: PMC4229138  PMID: 25390895
13.  Clinical Usefulness of Hydromorphone-OROS in Improving Sleep Disturbances in Korean Cancer Patients: A Multicenter, Prospective, Open-Label Study 
To evaluate the efficacy of hydromorphone-OROS (HM-OROS) in reducing sleep disturbance and relieving cancer pain.
Materials and Methods
One hundred twenty cancer patients with pain (numeric rating scale [NRS] ≥ 4) and sleep disturbance (NRS ≥ 4) were evaluated. The initial HM-OROS dosing was based on previous opioid dose (HM-OROS:oral morphine=1:5). Dose adjustment of the study drug was permitted at the investigator’s discretion. Pain intensity, number of breakthrough pain episodes, and quality of sleep were evaluated.
A total of 120 patients received at least one dose of HM-OROS; 74 of them completed the final assessment. Compared to the previous opioids, HM-OROS reduced the average pain NRS from 5.3 to 4.1 (p < 0.01), worst pain NRS from 6.7 to 5.4 (p < 0.01), sleep disturbance NRS from 5.9 to 4.1 (p < 0.01), incidence of breakthrough pain at night from 2.63 to 1.53 times (p < 0.001), and immediate-release opioids use for the management of breakthrough pain from 0.83 to 0.39 times per night (p = 0.001). Of the 74 patients who completed the treatment, 83.7% indicated that they preferred HM-OROS to the previous medication. The adverse events (AEs) were somnolence, asthenia, constipation, dizziness, and nausea.
HM-OROS was efficacious in reducing cancer pain and associated sleep disturbances. The AEs were manageable.
PMCID: PMC4206066  PMID: 25043822
Cancer pain; Sleep disturbance; Hydromorphone-OROS (HM-OROS)
14.  Changes in Osteoblastic Activity in Patient Who Received Bortezomib as Second Line Treatment for Plasma Cell Myeloma: A Prospective Multicenter Study 
BioMed Research International  2014;2014:245247.
We conducted a prospective multicenter study identifying the role of bortezomib in patients with relapsed or refractory plasma cell myeloma (PCM) in bone resorption and formation via bone turnover markers. A total of 104 patients received at least 1 cycle of bortezomib. Most of them had advanced disease (n = 89). Among them, 75 patients completed 4 cycles of treatment. Most of the patients (81.7%) were treated in combination with steroid. After the 4th cycle treatment, 47 of 75 patients achieved CR, nCR, VGPR, and PR (64.4%), while 26 patients achieved less than PR (35.6%). The proportion of patients who achieved ≥ PR increased as patients received more treatment cycles, reaching 90% after the 8th cycle. DKK-1 levels decreased significantly posttreatment. Bone formation markers (bALP and OC) and osteoclast regulator such as sRANKL also decreased significantly. These findings were observed primarily in patients who received steroid and who had a longer disease duration. While sRANKL demonstrated significant reduction posttreatment, osteoprotegerin (OPG) level did not significantly change posttreatment, resulting in a decreased sRANKL/OPG ratio (P = 0.037). In conclusion, our clinical data suggest that treatment with bortezomib and steroid may rearrange the metabolic balance between osteoblast and osteoclast activities in PCM.
PMCID: PMC4094867  PMID: 25050331
15.  Diagnostic Utility of Multiprobe Fluorescence in situ Hybridization Assay for Detecting Cytogenetic Aberrations in Acute Leukemia 
Annals of Laboratory Medicine  2014;34(3):198-202.
Specific cytogenetic aberrations detected by conventional karyotyping or FISH play a major role in the diagnosis, prognosis, and treatment of patients with acute leukemia. The FISH technique enhances the capacity of conventional karyotyping to detect subtle chromosomal aberrations. Multiprobe FISH assay (Cytocell, UK) can hybridize multiple probes to a single slide, thereby increasing the detection rate of cytogenetic aberrations. This study aimed to evaluate multiprobe FISH in detecting cytogenetic abnormalities in acute leukemia.
Thirty newly diagnosed acute leukemia patients who attended the hematology clinic at Dong-A University Hospital from October 2008 to October 2012 were enrolled in the study. The multiprobe FISH results were compared with those of G-banding.
Multiprobe FISH detected the chromosomal aberrations identified by G-banding, as well as additional aberrations in 6 of 30 (20.0%) cases, which included ETV6/RUNX1 translocation, p16 deletion, TP53 deletion, and IGH break-apart.
The multiprobe FISH assay was a more sensitive and reliable technique compared with G-banding. It was also more cost-effective and yielded faster results.
PMCID: PMC3999317  PMID: 24790906
Multiprobe FISH; Acute leukemia; Cytogenetic aberration
16.  Prevention of Venous Thromboembolism, 2nd Edition: Korean Society of Thrombosis and Hemostasis Evidence-Based Clinical Practice Guidelines 
Journal of Korean Medical Science  2014;29(2):164-171.
In 2010, we proposed the first Korean Guidelines for the Prevention of Venous Thromboembolism (VTE). It was applicable to Korean patients, by modifying the contents of the second edition of the Japanese guidelines for the prevention of VTE and the 8th edition of the American College of Chest Physicians (ACCP) evidence-based clinical practice guidelines. From 2007 to 2011, we conducted a nationwide study regarding the incidence of VTE after major surgery using the Health Insurance Review and Assessment Service (HIRA) database. In addition, we have considered the 9th edition of the ACCP Evidenced-Based Clinical Practice Guidelines, published in 2012. It emphasized the importance of clinically relevant events as opposed to asymptomatic outcomes with preferences for both thrombotic and bleeding outcomes. Thus, in the development of the new Korean guidelines, three major points were addressed: 1) the new guidelines stratify patients into 4 risk groups (very low, low, moderate, and high) according to the actual incidence of symptomatic VTE from the HIRA databases; 2) the recommended optimal VTE prophylaxis for each group was modified according to condition-specific thrombotic and bleeding risks; 3) guidelines are intended for general information only, are not medical advice, and do not replace professional medical care and/or physician advice.
Graphical Abstract
PMCID: PMC3923992  PMID: 24550640
Guideline; Prevention; Venous Thromboembolism; Bleeding
17.  Working Memory Impairment in Calcineurin Knock-out Mice Is Associated with Alterations in Synaptic Vesicle Cycling and Disruption of High-Frequency Synaptic and Network Activity in Prefrontal Cortex 
The Journal of Neuroscience  2013;33(27):10938-10949.
Working memory is an essential component of higher cognitive function, and its impairment is a core symptom of multiple CNS disorders, including schizophrenia. Neuronal mechanisms supporting working memory under normal conditions have been described and include persistent, high-frequency activity of prefrontal cortical neurons. However, little is known about the molecular and cellular basis of working memory dysfunction in the context of neuropsychiatric disorders. To elucidate synaptic and neuronal mechanisms of working memory dysfunction, we have performed a comprehensive analysis of a mouse model of schizophrenia, the forebrain-specific calcineurin knock-out mouse. Biochemical analyses of cortical tissue from these mice revealed a pronounced hyperphosphorylation of synaptic vesicle cycling proteins known to be necessary for high-frequency synaptic transmission. Examination of the synaptic vesicle cycle in calcineurin-deficient neurons demonstrated an impairment of vesicle release enhancement during periods of intense stimulation. Moreover, brain slice and in vivo electrophysiological analyses showed that loss of calcineurin leads to a gene dose-dependent disruption of high-frequency synaptic transmission and network activity in the PFC, correlating with selective working memory impairment. Finally, we showed that levels of dynamin I, a key presynaptic protein and calcineurin substrate, are significantly reduced in prefrontal cortical samples from schizophrenia patients, extending the disease relevance of our findings. Our data provide support for a model in which impaired synaptic vesicle cycling represents a critical node for disease pathologies underlying the cognitive deficits in schizophrenia.
PMCID: PMC3718364  PMID: 23825400
18.  Clinical Outcomes and Prognostic Factors of Empirical Antifungal Therapy with Itraconazole in the Patients with Hematological Malignancies: A Prospective Multicenter Observational Study in Korea 
Yonsei Medical Journal  2013;55(1):9-18.
To identify prognostic factors for the outcomes of empirical antifungal therapy, we performed a multicenter, prospective, observational study in immunocompromised patients with hematological malignancies.
Materials and Methods
Three hundred seventy-six patients (median age of 48) who had neutropenic fever and who received intravenous (IV) itraconazole as an empirical antifungal therapy for 3 or more days were analyzed. The patients with possible or probable categories of invasive fungal disease (IFD) were enrolled.
The overall success rate was 51.3% (196/376). Age >50 years, underlying lung disease (co-morbidity), poor performance status [Eastern Cooperative Oncology Group (ECOG) ≥2], radiologic evidence of IFD, longer duration of baseline neutropenic fever (≥4 days), no antifungal prophylaxis or prophylactic use of antifungal agents other than itraconazole, and high tumor burden were associated with decreased success rate in univariate analysis. In multivariate analysis, age >50 years (p=0.009) and poor ECOG performance status (p=0.005) were significantly associated with poor outcomes of empirical antifungal therapy. Twenty-two patients (5.9%) discontinued itraconazole therapy due to toxicity.
We concluded that empirical antifungal therapy with IV itraconazole in immunocompromised patients is effective and safe. Additionally, age over 50 years and poor performance status were poor prognostic factors for the outcomes of empirical antifungal therapy with IV itraconazole.
PMCID: PMC3874917  PMID: 24339281
Hematological malignancy; prognosis; itraconazole; empirical antifungal therapy
19.  Success Rate and Risk Factors for Failure of Empirical Antifungal Therapy with Itraconazole in Patients with Hematological Malignancies: A Multicenter, Prospective, Open-Label, Observational Study in Korea 
We assessed the success rate of empirical antifungal therapy with itraconazole and evaluated risk factors for predicting the failure of empirical antifungal therapy. A multicenter, prospective, observational study was performed in patients with hematological malignancies who had neutropenic fever and received empirical antifungal therapy with itraconazole at 22 centers. A total of 391 patients who had abnormal findings on chest imaging tests (31.0%) or a positive result of enzyme immunoassay for serum galactomannan (17.6%) showed a 56.5% overall success rate. Positive galactomannan tests before the initiation of the empirical antifungal therapy (P=0.026, hazard ratio [HR], 2.28; 95% confidence interval [CI], 1.10-4.69) and abnormal findings on the chest imaging tests before initiation of the empirical antifungal therapy (P=0.022, HR, 2.03; 95% CI, 1.11-3.71) were significantly associated with poor outcomes for the empirical antifungal therapy. Eight patients (2.0%) had premature discontinuation of itraconazole therapy due to toxicity. It is suggested that positive galactomannan tests and abnormal findings on the chest imaging tests at the time of initiation of the empirical antifungal therapy are risk factors for predicting the failure of the empirical antifungal therapy with itraconazole. (Clinical Trial Registration on National Cancer Institute website, NCT01060462)
PMCID: PMC3890478  PMID: 24431907
Hematological Malignancy; Itraconazole; Empirical Antifungal Therapy; Galactomannan Test
20.  Balance of calcineurin Aα and CDK5 activities sets release probability at nerve terminals 
The control of neurotransmitter release at nerve terminals is of profound importance for neurological function and provides a powerful control system in neural networks. We show that the balance of enzymatic activities of the alpha isoform of the phosphatase calcineurin (CNAα) and the kinase CDK5 has a dramatic influence over single AP-driven exocytosis at nerve terminals. Acute or chronic loss of these enzymatic activities results in a 7-fold impact on single action potential-driven exocytosis. We demonstrate that this control is mediated almost entirely through Cav2.2 (N-type) voltage-gated calcium channels as blocking these channels with a peptide toxin eliminates modulation by these enzymes. We found that a fraction of nerve terminals are kept in a presynaptically silent state with no measurable Ca2+ influx driven by single AP stimuli due to the balance of CNAα and CDK5 activities as blockade of either CNAα or CDK5 activity changes the proportion of presynaptically silent nerve terminals. Thus CNAα and CDK5 enzymatic activities are key determinants of release probability.
PMCID: PMC3808255  PMID: 23699505
21.  Prognostic significance of thymidylate synthase, thymidine phosphorylase and dihydropyrimidine dehydrogenase expression in biliary tract cancer patients receiving adjuvant 5-fluorouracil-based chemotherapy 
Molecular and Clinical Oncology  2013;1(6):987-994.
Biliary tract cancer (BTC) is a relatively uncommon type of cancer, accounting for ∼4% of the malignant neoplasms of the gastrointestinal tract. The aim of this study was to determine whether the expression of thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) predict clinical outcome in BTC patients treated with adjuvant 5-fluorouracil (5-FU)-based chemotherapy. TS and TP expression were found to be significantly correlated with cancer location (P=0.044 and 0.031, respectively). The multivariate analysis revealed that age [hazard ratio (HR)=2.157, P=0.008], stage (HR=2.234, P<0.001), resection margin status (HR=2.748, P=0.004) and TP expression (HR=2.014, P=0.039) were independently associated with overall survival (OS).
PMCID: PMC3915652  PMID: 24649282
biliary tract cancer; 5-fluorouracil; thymidine phosphorylase
22.  Prognostic significance of neutrophil lymphocyte ratio and platelet lymphocyte ratio in advanced gastric cancer patients treated with FOLFOX chemotherapy 
BMC Cancer  2013;13:350.
Several inflammatory response materials could be used for prediction of prognosis of cancer patients. The neutrophil lymphocyte ratio (NLR), and the platelet lymphocyte ratio (PLR) have been introduced for prognostic scoring system in various cancers. The objective of this study was to determine whether the NLR or the PLR would predict the clinical outcomes in advanced gastric cancer patients treated with oxaliplatin/ 5-fluorouracil (FOLFOX).
The study population consisted of 174 advanced gastric cancer patients. Patients were treated with 85 mg/m2 of oxaliplatin as a 2-h infusion at day 1 plus 20 mg/m2 of leucovorin over 10 min, followed by 5-FU bolus 400 mg/m2 and 22-h continuous infusion of 600 mg/m2 at days 1-2. Treatment was repeated in 2-week intervals. The NLR and PLR were calculated from complete blood counts in laboratory test before and after first cycle of chemotherapy.
NLR was a useful prognostic biomarker for predicting inferior overall survival (OS) (p = 0.005), but was not associated with progression free survival (PFS) (p = 0.461). The normalization of NLR after one cycle of chemotherapy was found to be in association with significant improvement in PFS (5.3 months vs. 2.4 months, p < 0.001), and OS (11.9 months vs. 4.6 months, p < 0.001). The normalization of PLR was also associated with longer PFS (5.6 months vs. 3.4 months, p = 0.006), and OS (16.9 months vs. 10.9 months, p = 0.002). In multivariate analysis, changes in NLR were associated with PFS (Hazard ratio (HR): 2.297, 95% confidence interval (CI): 1.429-3.693, p = 0.001). The NLR, (HR: 0.245, 95% CI: 0.092-0.633, p = 0.004), PLR (HR: 0.347, 95% CI: 0.142-0.847, p = 0.020), changes in NLR (HR: 2.468, 95% CI: 1.567-3.886, p < 0.001), and changes in PLR (HR: 1.473, 95% CI: 1.038-2.090, p = 0.030) were independent prognostic markers for OS.
This study demonstrates that NLR, PLR, and changes in NLR or PLR are independent prognostic factor for OS in patients with advanced gastric cancer treated with chemotherapy. These specific factors may also help in identifying the patients, who are more sensitive to FOLFOX regimen.
PMCID: PMC3729814  PMID: 23876227
Neutrophil; Lymphocyte; Platelet; Gastric neoplasm
23.  Molecular mechanism of sequence-dependent stability of RecA filament 
Nucleic Acids Research  2013;41(16):7738-7744.
RecA is a DNA-dependent ATPase and mediates homologous recombination by first forming a filament on a single-stranded (ss) DNA. RecA binds preferentially to TGG repeat sequence, which resembles the recombination hot spot Chi (5′-GCTGGTGG-3′) and is the most frequent pattern (GTG) of the codon usage in Escherichia coli. Because of the highly dynamic nature of RecA filament formation, which consists of filament nucleation, growth and shrinkage, we need experimental approaches that can resolve each of these processes separately to gain detailed insights into the molecular mechanism of sequence preference. By using a single-molecule fluorescence assay, we examined the effect of sequence on individual stages of nucleation, monomer binding and dissociation. We found that RecA does not recognize the Chi sequence as a nucleation site. In contrast, we observed that it is the reduced monomer dissociation that mainly determines the high filament stability on TGG repeats. This sequence dependence of monomer dissociation is well-correlated with that of ATP hydrolysis, suggesting that DNA sequence dictates filament stability through modulation of ATP hydrolysis.
PMCID: PMC3763553  PMID: 23804763
24.  Third-line docetaxel chemotherapy for recurrent and metastatic gastric cancer 
To determine the efficacy and toxicity of docetaxel as a third-line therapy for patients with relapsed gastric cancer who have undergone modified oxaliplatin-fluorouracil (m-FOLFOX)-4 and modified irinotecan-fluorouracil (m-FOLFIRI) regimens.
We analyzed 33 patients who had been histologically diagnosed with adenocarcinoma of the stomach and who had progressed after m-FOLFOX-4 and m-FOLFIRI regimens. Patients were treated with cycles of 75 mg/m2 docetaxel on day 1 every 3 weeks.
The median age of the patients was 56.0 years (range, 31.0 to 74.0), and 73% of the patients (24/33) had an Eastern Cooperative Oncology Group performance status of 0 or 1. All patients were evaluated in terms of tumor response: five (15%), nine (27%), and 19 (58%) patients experienced a partial response, stable disease, and progressive disease, respectively. The median time to progression was 2.1 months (95% confidence interval [CI], 1.63 to 2.58), and overall survival was 4.7 months (95% CI, 3.20 to 6.20), from the start of the docetaxel regimen. Assessing patients' toxicity profiles, the median number of cycles was 2.0 (range, 1.0 to 12.0). The major hematologic toxicities included grade 3 to 4 neutropenia (19/33, 58%), grade 3 to 4 thrombocytopenia (2/33, 6%), and grade 3 to 4 anemia (5/33, 15%). Neutropenic fever developed in three patients (3/33, 9%). The nonhematological toxicities were nausea and vomiting (10/33, 30%), abdominal pain (4/33, 12%), skin rash (1/33, 3%), and fluid retention (3/33, 9%).
Docetaxel is a feasible third-line therapy regimen for patients with advanced gastric cancer after m-FOLFIRI and m-FOLFOX-4 regimens.
PMCID: PMC3654129  PMID: 23682225
Advanced gastric cancer; Docetaxel; Salvage therapy
25.  The relationship of Vascular endothelial growth factor gene polymorphisms and clinical outcome in advanced gastric cancer patients treated with FOLFOX: VEGF polymorphism in gastric cancer 
BMC Cancer  2013;13:43.
The aim of this study is to evaluate the associations between vascular endothelial growth factor (VEGF) Single-nucleotide polymorphisms (SNPs) and clinical outcome in advanced gastric cancer patients treated with oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX).
Genomic DNA was isolated from whole blood, and six VEGF (−2578C/A, -2489C/T, -1498 T/C, -634 G/C, +936C/T, and +1612 G/A) gene polymorphisms were analyzed by PCR. Levels of serum VEGF were measured using enzyme-linked immunoassays.
Patients with G/G genotype for VEGF -634 G/C gene polymorphism showed a lower response rate (22.2%) than those with G/C or C/C genotype (32.3%, 51.1%; P = 0.034). Patients with the VEGF -634 G/C polymorphism G/C + C/C genotype had a longer progression free survival (PFS) of 4.9 months, compared with the PFS of 3.5 months for those with the G/G (P = 0.043, log-rank test). By multivariate analysis, this G/G genotype of VEGF -634 G/C polymorphism was identified as an independent prognostic factor (Hazard ratio 1.497, P = 0.017).
Our data suggest that G/G genotype of VEGF -634 G/C polymorphism is related to the higher serum levels of VEGF, and poor clinical outcome in advanced gastric cancer patients.
PMCID: PMC3573956  PMID: 23374220
VEGF; Polymorphism; Gastric cancer

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