Gaussian mixture model-based classification of dynamic contrast enhanced MRI data for identifying diverse tumor microenvironments: preliminary results

Tumor hypoxia develops heterogeneously, affects radiation sensitivity and the development of metastases. Prognostic information derived from the in vivo characterization of the spatial distribution of hypoxic areas in solid tumors can be of value for radiation therapy planning and for monitoring the early treatment response. Tumor hypoxia is caused by an imbalance between the supply and consumption of oxygen. The tumor oxygen supply is inherently linked to its vasculature and perfusion which can be evaluated by dynamic contrast enhanced (DCE-) MRI using the contrast agent Gd-DTPA. Thus, we hypothesize that DCE-MRI data may provide surrogate information regarding tumor hypoxia. In this study, DCE-MRI data from a rat prostate tumor model were analysed with a Gaussian mixture model (GMM)-based classification to identify perfused, hypoxic and necrotic areas for a total of ten tumor slices from six rats, of which one slice was used as training data for GMM classifications. The results of pattern recognition analyzes were validated by comparison to corresponding Akep maps defining the perfused area (0.84 ± 0.09 overlap), hematoxylin and eosin (H&E)-stained tissue sections defining necrosis (0.64 ± 0.15 overlap) and pimonidazole-stained sections defining hypoxia (0.72 ± 0.17 overlap), respectively. Our preliminary data indicate the feasibility of a GMM-based classification to identify tumor hypoxia, necrosis and perfusion/permeability from non-invasively acquired, in vivo DCE-MRI data alone, possibly obviating the need for invasive procedures, such as biopsies, or exposure to radioactivity, such as positron emission tomography (PET) exams.

Abstract 1853: Reduced glucose uptake and inhibition of ATP synthase by mefloquine results in death of glioblastoma multiforme

A number of studies have shown that increased expression of glucose transporters (GLUT) facilitates the high level of glycolytic activity found in most cancers. As well, increased expression of GLUT3 has been linked to chemoresistance towards temozolomide (TMZ), the current drug of choice for the treatment of malignant glioma (GBM). This relation between glucose metabolism on one side, and cancer survival and drug resistance on the other, demands further interrogation to more precisely dissect the mechanism(s) driving this cellular adaptation. Insights as to the relation between tumor metabolism and chemoresistance development can provide important information in order to exploit this mechanism as a potential drug target. To this end, we have investigated whether mefloquine (MQ), an FDA-approved antimalarial agent, can be used to inhibit the growth of glioma cells expressing high levels of GLUT3.

We evaluated the effects of MQ on cellular viability and proliferation by MTT assay and colony formation assay. Markers of apoptosis (e.g. cleavage of caspase 7 and PARP) were analyzed by Western blot, and necrosis was quantitated by LDH release. The effect of MQ on GLUT3 levels was studied by Western blot, and the uptake of glucose was analyzed by using fluorescently labeled 2-deoxy-glucose. Mitochondrial respiration and glycolytic flux were measured using the Seahorse Extracellular Flux Analyzer. We also analyzed the effects of MQ on individual complexes of the electron transport chain.

MQ exerted cytotoxic effects on GBM cell lines, including highly TMZ-resistant variants.Cell death was primarily necrosis, with only limited involvement of apoptosis. Treatment with MQ was able to reduce GLUT3 expression, which correlated with reduced glucose uptake in a dose-dependent manner. Methyl pyruvate treatment provided only partial protection from MQ mediated cytotoxicity. MQ also displayed direct inhibition of complex V (ATP synthase) of the mitochondrial electron transport chain. Overall cellular ATP production was severely down-regulated by MQ.

The cytotoxic potency of MQ on GBM cell lines, including highly drug-resistant variants, appears to be caused by drug-induced depletion of cellular energy (ATP), due to decreased glycolytic flux (as a result of reduced glucose uptake) in combination with inhibition of mitochondrial respiration (as a result of potent inhibition of ATP synthase). Exhaustion of cellular ATP precludes apoptosis, which might explain why MQ primarily triggers necrotic cell death. Considering the sugar-craving phenotype of most tumor cells, MQ appears to be well suited to exploit this feature in order to selectively starve malignant cells to death. Thus, our preliminary data suggest that MQ should be further investigated for cancer therapeutic approaches aimed at tumor cell metabolism.

Citation Format: Natasha Sharma, Dezheng Dong, Stan Louie, Heeyeon Cho, Thomas Chen, Florence Hofman, Axel Schonthal. Reduced glucose uptake and inhibition of ATP synthase by mefloquine results in death of glioblastoma multiforme. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1853. doi:10.1158/1538-7445.AM2013-1853

Abstract P1-15-11: The Kampo medicine Goshajinkigan prevents docetaxel-related peripheral neuropathy in breast cancer patients

Background: Although taxanes have become a key chemotherapeutic drug in breast cancer treatment. Taxanes inhibit the growth of cancer cells by disrupting the functioning of their microtubules; however, the microtubules of nerve cells are also affected by this process, which can cause neurological disorders. The Kampo medicine Goshajinkigan (GJG) is a traditional Japanese medicine that is used for the treatment of several neurological symptoms including pain and numbness, GJG is comprised of 10 herbs, each of which contains numerous active ingredients. Recently, GJG has been reported to prevent anticancer drug-induced peripheral neuropathy in colorectal cancer. We performed the present prospective randomized study to confirm the effects of GJG and mecobalamin (B12) against docetaxel (DOC)-associated peripheral neurotoxicity in breast cancer patients.

Patients and method: Between May 2007 and April 2011, 60 breast cancer patients were treated with DOC. Thirty-three patients (GJG group) received oral administration of 7.5 g/day GJG and 27 patients (B12 group) received oral administration of 1500 μg/day B12. The patients were treated with TC (75mg/m2 docetaxel and 600 mg/m2 cyclophosphamide) every 3 weeks for 4 cycles, docetaxel alone (100mg/m2) every 3 weeks for 4 cycles, and XT (900mg/m2 capecitabine administered orally twice a day on days 1–14 plus 60 mg/m2 docetaxel) every 3 weeks for 6 cycles. Peripheral neuropathy was evaluated during every course according to DEB-NTC (Neurotoxicity Criteria of Debiopharm), Common Terminology Criteria for Adverse Events (NCI-CTC) ver.3.0, and a visual analogue scale (VAS).

Results: The median age of the GJG group was 58 years old (35 to 70 years old), the B12 group was 55 years old (33 to 69 years old), and they were all females. For the regimens, in the GJG group, TC, DOC only, and XT were administered in 19 cases, 13 cases and 1 case, respectively. In the B12 group, they were 15 cases, 11 cases and 12 cases, respectively. The cumulative dose of DOC was 338.5 mg/m2 in the GJG group, and 340 mg/m2 in the B12 group. Peripheral neuropathy occurred significantly less frequently in the GJG group (39.3%) than the B12 group (88.9%) (p < 0.01). In the GJG group, grade 1 DEB-NTC was observed in 2 cases, grade 2 in 5 cases and grade 3 in 5 cases. Grade 1 NCI-CTC was observed in 7 cases, grade 2 in 6 cases. In the B12 group, grades 1, 2 and 3 DEB-NTC were observed in one case, 12 cases and 12 cases, respectively; and grades 1, 2 and 3 NCI-CTC were observed in 11 cases, 12 cases and one case. The mean VAS scores for numbness after chemotherapy were 2.7 in the GJG group and 4.9 in the B12 group (p < 0.01). The incidence of grade 2/3 peripheral neuropathy was lower in the GJG group than the B12 group. Peripheral neuropathy was significantly controlled in the GJG group.

Conclusion: The present study is the first prospective control study to prove the efficacy of GJG against docetaxel-induced peripheral neuropathy in breast cancer patients. Our findings suggest that DOC-associated peripheral neurotoxicity can be suppressed by the administration of GJG. It will be necessary to confirm the usefulness of GJG in larger prospective studies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-15-11.

Nociceptive and pro-inflammatory effects of dimethylallyl pyrophosphate via TRPV4 activation

BACKGROUND AND PURPOSE

Sensory neuronal and epidermal transient receptor potential ion channels (TRPs) serve an important role as pain sensor molecules. While many natural and synthetic ligands for sensory TRPs have been identified, little is known about the endogenous activator for TRPV4. Recently, we reported that endogenous metabolites produced by the mevalonate pathway regulate the activities of sensory neuronal TRPs. Here, we show that dimethylallyl pyrophosphate (DMAPP), a substance produced by the same pathway is an activator of TRPV4.

EXPERIMENTAL APPROACH

We examined the effects of DMAPP on sensory TRPs using Ca²⁺ imaging and whole-cell electrophysiology experiments with a heterologous expression system (HEK293T cells transfected with individual TRP channels), cultured sensory neurons and keratinocytes. We then evaluated nociceptive behavioural and inflammatory changes upon DMAPP administration in mice in vivo.

KEY RESULTS

In the HEK cell heterologous expression system, cultured sensory neurons and keratinocytes, µM concentrations of DMAPP activated TRPV4. Agonistic and antagonistic potencies of DMAPP for other sensory TRP channels were examined and activation of TRPV3 by camphor was found to be inhibited by DMAPP. In vivo assays, intraplantar injection of DMAPP acutely elicited nociceptive flinches that were prevented by pretreatment with TRPV4 blockers, indicating that DMAPP is a novel pain-producing molecule through TRPV4 activation. Further, DMAPP induced acute inflammation and noxious mechanical hypersensitivities in a TRPV4-dependent manner.

CONCLUSIONS AND IMPLICATIONS

Overall, we found a novel sensory TRP acting metabolite and suggest that its use may help to elucidate the physiological role of TRPV4 in nociception and associated inflammation.

Rictor regulates cell migration by suppressing RhoGDI2

Rictor and its binding partner Sin1 are indispensable components of mTORC2 (mammalian Target of Rapamycin Complex 2). The mTORC2 signaling complex functions as the regulatory kinase of the distinct members of AGC kinase family known to regulate cell proliferation and survival. In the early chemotaxis studies in Dictyostelium, the rictor's ortholog has been identified as a regulator of cell migration. How rictor regulates cell migration is poorly characterized. Here we show that rictor regulates cell migration by controlling a potent inhibitor of Rho proteins known as the Rho-GDP dissociation inhibitor 2 (RhoGDI2). Based on our proteomics study we identified that the rictor-dependent deficiency in cell migration is caused by up-regulation of RhoGDI2 leading to a low activity of Rac and Cdc42. We found that a suppression of RhoGDI2 by rictor is not related to the Sin1 or raptor function that excludes a role of mTORC2 or mTORC1 in regulation of RhoGDI2. Our study reveals that rictor by suppressing RhoGDI2 promotes activity of the Rho proteins and cell migration.

Preferential killing of triple-negative breast cancer cells in vitro and in vivo when pharmacological aggravators of endoplasmic reticulum stress are combined with autophagy inhibitors

The cellular processes of autophagy and endoplasmic reticulum stress (ERS) appear to be interconnected, and it has been proposed that autophagy may serve to reduce ERS via removal of terminally misfolded and aggregated proteins. Conversely, there are indications that blockage of autophagy may increase ERS. Based on earlier work demonstrating that pharmacologically aggravated ERS can result in tumor cell killing, we investigated whether blockage of autophagy would enhance this effect in a therapeutically useful manner. We therefore combined chloroquine (CQ), a pharmacological inhibitor of autophagy, with other drugs known to act as ERS aggravators (ERSA), namely nelfinavir (an HIV protease inhibitor) and celecoxib (a cyclooxygenase-2 inhibitor) or its non-coxib analog 2,5-dimethyl-celecoxib (DMC), and investigated combination drug effects in a variety of breast cancer cell lines. We found that the addition of CQ resulted in synergistic enhancement of tumor cell killing by ERSA compounds, particularly in triple-negative breast cancer (TNBC) cells. This combination effect could also be confirmed in an in vivo model, where CQ boosted low-dose ERSA effects, resulting in rapid deterioration of xenografted tumors in mice. Altogether, our results indicate that combinations of an autophagy inhibitor with pharmacological ERSA (i.e. compounds that lead to ER stress aggravation) should be further explored for potential therapy of otherwise difficult-to-treat TNBC.

2009-2010 novel influenza A (H1N1) vaccination coverage in the Republic of Korea

This study aimed to assess vaccination coverage for novel influenza A (H1N1) in Korea using a immunization registry system as the data source. Vaccination coverage was found to be 26.1% for the total population and 54.4% for priority groups targeted by a national vaccination campaign between October 27, 2009, to March 31, 2010. The factors associated with increased coverage were rapid vaccination and free vaccination; these factors may need to be considered in future pandemics.

Experimental venous thrombi: MRI characteristics with histopathological correlation

OBJECTIVES

The purpose of this study was to evaluate the MRI characteristics of venous thrombus over set time thresholds with histopathological correlation in a porcine model.

METHODS

Inferior vena cava thrombi were induced in 12 pigs. MRI was performed in three pigs 2 h, 1 day, 3 days and 2 weeks after thrombus induction.

RESULTS

The MRI characteristics were analysed in correlation with histopathological findings. The thrombi after 2 hours, which consisted of red blood cells (RBCs), showed isointensity on T(1 )weighted images (T(1)WIs) and hyperintensity on both T(2 )weighted images (T(2)WIs) and diffusion-weighted images (DWIs). The mean apparent diffusion coefficient (ADC) value was 1.93 × 10(-3) mm(2) s(-1). The thrombi after Day 1, which consisted of RBCs and migrating neutrophils at the periphery, showed isointensity on T(1)WIs, slight hyperintensity on T(2)WIs and hypointensity on DWIs. The mean ADC value was 1.62 × 10(-3) mm(2) s(-1) [corrected]. The thrombi after Day 3, which consisted of RBCs and peripheral inflammatory cells including macrophages, showed isointensity with peripheral hyperintense regions on T(1)WIs and hypointensity on both T(2)WIs and DWIs. The mean ADC value was 1.67 × 10(-3) mm(2) s(-1). After 2 weeks, the thrombi, which revealed RBC lysis surrounded by granulation tissues, showed isointensity on T(1)WIs and hyperintensity on T(2)WIs and DWIs. The mean ADC value was 2.48 × 10(-3) mm(2) s(-1).

CONCLUSION

The temporal MRI characteristics seemed to be related to chemical and physical changes in RBC and organisation of granulation tissues. Free radicals generated by macrophages might also be related to some extent.

17(R)-resolvin D1 specifically inhibits transient receptor potential ion channel vanilloid 3 leading to peripheral antinociception

BACKGROUND AND PURPOSE

Transient receptor potential ion channel vanilloid 3 (TRPV3) is expressed in skin keratinocytes and plays an important role in thermal and chemical nociceptions in the periphery. The presence of TRPV3 inhibitors would improve our understanding of TRPV3 function and help to develop receptor-specific analgesics. However, little is known about physiological substances that specifically inhibit TRPV3 activity. Here, we investigated whether 17(R)-resolvin D1 (17R-RvD1), a naturally occurring pro-resolving lipid specifically affects TRPV3 activity.

EXPERIMENTAL APPROACH

We examined the effect of 17R-RvD1 on sensory TRP channels using Ca(2+) imaging and whole cell electrophysiology experiments in a HEK cell heterologous expression system, cultured sensory neurons and keratinocytes. We also examined changes in sensory TRP agonist-specific acute licking/flicking or flinching behaviours and mechanical and thermal pain behaviours using Hargreaves, Randall-Selitto and von Frey assay systems in the absence and presence of inflammation.

KEY RESULTS

We showed that 17R-RvD1 specifically suppresses TRPV3-mediated activity at nanomolar and micromolar concentrations. The voltage-dependence of TRPV3 activation by camphor was shifted rightwards by 17R-RvD1, which indicates its inhibitory mechanism is as a result of a shift in voltage-dependence. Consistently, TRPV3-specific acute pain behaviours were attenuated by locally injected 17R-RvD1. Moreover, the administration of 17R-RvD1 significantly reversed the thermal hypersensitivity that occurs during an inflammatory response. Knockdown of epidermal TRPV3 blunted these antinociceptive effects of 17R-RvD1.

CONCLUSIONS AND IMPLICATIONS

17R-RvD1 is a novel natural inhibitory substance specific for TRPV3. The results of our behavioural studies suggest that 17R-RvD1 has acute analgesic potential via TRPV3-specific mechanisms.

Association between SNPs and gene expression in multiple regions of the human brain

Identifying the genetic cis associations between DNA variants (single-nucleotide polymorphisms (SNPs)) and gene expression in brain tissue may be a promising approach to find functionally relevant pathways that contribute to the etiology of psychiatric disorders. In this study, we examined the association between genetic variations and gene expression in prefrontal cortex, hippocampus, temporal cortex, thalamus and cerebellum in subjects with psychiatric disorders and in normal controls. We identified cis associations between 648 transcripts and 6725 SNPs in the various brain regions. Several SNPs showed brain regional-specific associations. The expression level of only one gene, PDE4DIP, was associated with a SNP, rs12124527, in all the brain regions tested here. From our data, we generated a list of brain cis expression quantitative trait loci (eQTL) genes that we compared with a list of schizophrenia candidate genes downloaded from the Schizophrenia Forum (SZgene) database (http://www.szgene.org/). Of the SZgene candidate genes, we found that the expression levels of four genes, HTR2A, PLXNA2, SRR and TCF4, were significantly associated with cis SNPs in at least one brain region tested. One gene, SRR, was also involved in a coexpression module that we found to be associated with disease status. In addition, a substantial number of cis eQTL genes were also involved in the module, suggesting eQTL analysis of brain tissue may identify more reliable susceptibility genes for schizophrenia than case-control genetic association analyses. In an attempt to facilitate the identification of genetic variations that may underlie the etiology of major psychiatric disorders, we have integrated the brain eQTL results into a public and online database, Stanley Neuropathology Consortium Integrative Database (SNCID; http://sncid.stanleyresearch.org).

Epidemiology of Japanese encephalitis in South Korea, 2007-2010

BACKGROUND

Japanese encephalitis (JE) was the leading cause of viral encephalitis among children in South Korea in the 20(th) century. This study summarizes recent changes in the epidemiology of JE following the implementation of a vigorous immunization program in the country.

METHODS

Epidemiological investigations were performed for all reported laboratory-confirmed JE cases, and the cumulative incidence was calculated for the surveillance years 2007-2010.

RESULTS

During the surveillance period, 45 cases of JE were confirmed in the country, resulting in a cumulative incidence of 0.013-0.055 cases per 100 000 population. The median age of cases was 49.4 years, and by age group, 44.4% were aged 40-49 years. Just under a quarter (22.2%) of the cases were found to live close to a pigsty, while 42.2% of the cases were found to reside in the metropolitan areas of Seoul, Incheon, and Gyeonggi-do. None of the cases had a history of vaccination.

CONCLUSIONS

Although JE has traditionally been regarded as a children's disease, the majority of cases now occur in adults in countries where strong immunization programs exist, such as in South Korea. Consideration should be given to an adult vaccination policy in the near future.

Seroprevalence of measles among children affected by national measles elimination program in Korea, 2010

BACKGROUND

Following the implementation of national measles elimination plan in Korea, the elimination was declared in 2006. In order to sustain the elimination, high population immunity should be continuously monitored. To evaluate the current age-related susceptibility within the Korean population, we conducted the seroprevalence in children and adolescents who were affected by the national measles elimination plan.

METHODS

We used residual serum specimens to measure measles specific IgG and geometric mean titer (GMT) in birth cohorts 2007-2008 and 1997-2003. Among birth cohorts, 2007-2008 cohorts were grouped to evaluate the timeliness of first dose of MMR, 1994-2003 cohorts were grouped to evaluate the effect of keep-up MMR2 campaign, and 1992-1993 cohorts were grouped to evaluate the effect of catch-up campaign in 2001.

RESULTS

Overall, measles seropositivity rate was 86%. The highest seroprevalence of measles IgG was in birth cohorts 2007-2008. Measles seropositivity declined continuously in age groups. The birth cohorts 1994-1996 showed significantly lower levels of seropositivity and GMT than did the other birth cohorts.

CONCLUSION

Despite efforts to eliminate measles for the past 10 years in Korea, our study revealed specific birth cohorts remaining at risk for transmission. The adolescents born during 1994-1996 had the lowest measles seropositivity levels, and might represent a 'pocket' that has potential at increased risk for measles transmission. Further discussion for follow-up immunization should be placed for consideration in the near future.

A computable evolution equation for the joint response-excitation probability density function of stochastic dynamical systems

By using functional integral methods, we determine a computable evolution equation for the joint response-excitation probability density function of a stochastic dynamical system driven by coloured noise. This equation can be represented in terms of a superimposition of differential constraints, i.e. partial differential equations involving unusual limit partial derivatives, the first one of which was originally proposed by Sapsis & Athanassoulis. A connection with the classical response approach is established in the general case of random noise with arbitrary correlation time, yielding a fully consistent new theory for non-Markovian systems. We also address the question of computability of the joint response-excitation probability density function as a solution to a boundary value problem involving only one differential constraint. By means of a simple analytical example, it is shown that, in general, such a problem is undetermined, in the sense that it admits an infinite number of solutions. This issue can be overcome by completing the system with additional relations yielding a closure problem, which is similar to the one arising in the standard response theory. Numerical verification of the equations for the joint response-excitation density is obtained for a tumour cell growth model under immune response.

Magnetic field anisotropy based MR tractography

Non-invasive measurements of structural orientation provide unique information regarding the connectivity and functionality of fiber materials. In the present study, we use a capillary model to demonstrate that the direction of fiber structure can be obtained from susceptibility-induced magnetic field anisotropy. The interference pattern between internal and external magnetic field gradients carries the signature of the underlying anisotropic structure and can be measured by MRI-based water diffusion measurements. Through both numerical simulation and experiments, we found that this technique can determine the capillary orientation within 3°. Therefore, susceptibility-induced magnetic field anisotropy may be useful for an alternative tractography method when diffusion anisotropy is small at higher magnetic field strength without the need to rotate the subject inside the scanner.

Outbreak of measles in the Republic of Korea, 2007: importance of nosocomial transmission

BACKGROUND

From 2002 through 2006, Republic of Korea conducted extensive measles elimination activities and declared elimination in 2006. An outbreak of measles involving 180 confirmed cases occurred during 2007.

METHODS

An outbreak investigation was performed and enhanced surveillance was implemented. Detailed case investigations and laboratory testing included serologic and molecular diagnostic methods. Cases were classified according to World Health Organization and national guidelines.

RESULTS

During 2007, 451 suspected cases were reported and 180 (40%) cases were confirmed as measles during epidemiologic weeks 14-42. Incidence during the outbreak was 3.7 cases per million persons, excluding imported cases. Most confirmed cases were reported from Seoul; 137 (76%) cases were among children <24 months old, 124 (69%) case patients had no history of measles vaccination, and 81 (45%) case patients resulted from nosocomial transmission in 6 hospitals. Community members, patients, and health care workers all contributed to measles virus transmission. Limited outbreak control measures were implemented; high population immunity likely accounted for the self-limited transmission during this outbreak.

CONCLUSIONS

Limited outbreaks of measles, in which nosocomial transmission can play an important role, may occur after countries have declared elimination. Timely and opportunistic vaccination may help prevent such outbreaks; high-quality surveillance is critical for their detection.

National action plan for response to poliovirus importation

The Division of Vaccine-Preventable Disease Control and National Immunization Program of the Korea Centers for Disease Control and Prevention has prepared a plan of action as a guide for key actions that will be taken if a poliovirus outbreak occurs in the Republic of Korea. The history of poliomyelitis and vaccination against poliovirus in the nation was reviewed and the routine surveillance procedures that are currently in place were described. The principles and specific actions for an effective response to a poliovirus outbreak were prepared. The guidelines clearly outline the actions to be taken in case of a polio outbreak. When a suspected case of poliovirus infection is reported, an immediate epidemiological investigation is to be conducted. The response to a poliovirus outbreak includes case isolation, management of potential contacts and immunization. All stakeholders are to be made aware of what key actions should be taken at each stage of the response to a poliovirus outbreak in the nation.

Impact of c-kit mutations, including codons 557 and/or 558, on the recurrence-free survival after curative surgery in patients with GIST

12

Background: Recently, c-kit exon 11 deletions, including codons 557 and/or 558, have been reported to predict a worse prognosis in GIST patients. However, it is difficult to prove the correlation between genotype and tumor aggressiveness in the imatinib- adjuvant era because exon 11 mutations respond well to imatinib. In this study, we evaluated the impact of c-kit mutational status on recurrence-free survival (RFS) after resection of primary GIST.

Methods: Clinical and pathological characteristics of 89 GIST patients in our single institution study were retrospectively analyzed. Tumors were categorized into 4 subgroups based on their mutational locations; A1: mutated codons including neither 557 nor 558, A2: either 557 or 558, B1: only 557 and 558, B2: both 557 and 558. All of the patients underwent curative surgery, and none received adjuvant imatinib. The median duration of follow-up was 49 months.

Results: Tumors originated from the stomach (n=75/89, 84%), small intestine (n=10), and colorectum (n=4). Mutation subgroup B was associated with both Fletcher and Miettinen high-risk categories. The 2-year recurrence free survival rate for A1, A2, B1, B2, was 84.9%, 85.7%, 50%, 57%, respectively. Group B2 had a significantly worse RFS than groups A1 (p=0.0004) and A2 (p=0.0014). Multivariate analysis for RFS indicated that only the mutational subgroup was a significant prognostic factor (p=0.03, HR=2.42).

Conclusions: C-kit mutations, including both 557 and 558, affected the RFS of GIST patients after curative surgery, but those including either 557 or 558 did not. Our results indicate that the locations of c-kit mutations are associated with PFS, and they may therefore affect the selection of candidates with GIST for adjuvant imatinib.

No significant financial relationships to disclose.

Ethanol-induced DNA damage and the expression of repair-related molecules in human gastric carcinoma AGS cells with use of an acid pump antagonist and proton pump inhibitor

30

Background: Proton pump inhibitor (PPI) inhibits gastric acid secretion by strongly suppressing H + / K +- ATPase of parietal cells and is a major drug for peptic ulcers and gastroesophageal reflux. Recently it was reported that PPI has antioxidant and anti- inflammatory effects as well as a powerful acid inhibitory effect. To analyze the DNA repair capacity from the antioxidant effect of acid pump antagonist (Revanex-RN) and proton pump inhibitor (Omeprazole-OP), this study examined ethanol-induced DNA damage and the expression of repair related molecules in human gastric cancer AGS cells pretreated with an acid pump antagonist and a proton pump inhibitor.

Methods: AGS, a human gastric cancer cell line was obtained from ATCC, was treated with ethanol (0, 2, 4, 6, 8, 10%) during 1hr. MTT and Comet assay were performed to evaluate ethanol-induced DNA damage. The optimum concentration of ethanol which caused DNA damage was established. And AGS cells were cultured in proper concentration of RN or OP overnight. Then, these cells were treated with 5% ethanol during 1hr. DNA damage and recovery were represented the value of Olive tail moment in comet assay. Western blot was also performed to detect expression of DNA polymerase beta, APE/ref-1, PCNA, and GADD45.

Results: The DNA damage of AGS cell depended upon ethanol concentration distinctly. Damaged cells showed up recovered tendency in the group treated with low dose RN or OP. In addition, DNA repair enzymes including DNA polymerase beta and APE/ref-1 which were associated with mechanism of base excision repair (BER) were increased. A relevant protein such as GADD45 was also increased significantly.

Conclusions: PPI has capacity to recover damaged DNA, which is associated with increased expression of GADD45 directly. Therefore, PPI offers cancer prevention by reducing the level of DNA damage in the gastric mucosa. GADD45 is also likely to suggest that it could be used a major factor on the injury mechanism and an indicator of mucosal damage in stomach. Moreover, RN, an acid pump antagonist is expected to have the higher safety compared to the existing PPIs and considered to be equal to PPIs in terms of anti-cancer effect.

No significant financial relationships to disclose.

Novel multiphoton microscopy probe and feasibility study for colon cancer: Probe on trace elements–related antioxidant

463

Background: Multiphoton microscopy (MPM) has gained increasing popularity during the past few years because of the distinct advantages over single-photon microscopy, which includes increased penetration depth and low out-of-focus photodamage. However, there had been no report on multiphoton probes for malignancy. Previous studies reported that Zn and Cu ions which are co-factor of antioxidants such as superoxide dismutase (SOD), altered in malignancy tissue. The aim of this study was to evaluate application of the multiphoton (MP) probe of Zn and Cu for colon cancer tissues.

Methods: We monitored the Zn/Cu ions in the colon cancer cell lines with multiphoton probe Microscopy. The multiphoton probe AZn2+ (C38H38N6O3) and ACu+ (C34H47N3O3S4), we developed and obtained the patent on it, were stained in live cancer cell lines. The tissues of colon cancer, adenoma and normal mucosa were obtained by biopsy during colonoscopy. Then the tissues were stained with 20μM of the MP probes for Zn/Cu ions. The distribution and concentration of zinc and copper ions were monitored by MPM by following the change in MPEF along the depth of tissue.

Results: The majority of Zn2+ and Cu+ ions distributed in cytosole. The average multi-photon excited fluorescence (MPEF) intensities due to Cu, Zn, and Cu/Zn ratio were remarkably different between the normal mucosa and adenoma/adenocarcinoma tissues. The Zn2+ content was significantly lower and the Cu2+ content was significantly higher to result in a much lower the Zn/Cu ratio in adenoma/adenocarcinoma than in normal mucosa tissues.

Conclusions: We have obtained multiphoton microscopy images of normal and cancer cell lines as well as mucosa and adenoma/adenocarcinoma tissues labeled with newly developed MP probes AZn1 and ACu1.

No significant financial relationships to disclose.

Resolvin D1 attenuates activation of sensory transient receptor potential channels leading to multiple anti-nociception

BACKGROUND AND PURPOSE

Temperature-sensitive transient receptor potential ion channels (thermoTRPs) expressed in primary sensory neurons and skin keratinocytes play a crucial role as peripheral pain detectors. Many natural and synthetic ligands have been found to act on thermoTRPs, but little is known about endogenous compounds that inhibit these TRPs. Here, we asked whether resolvin D1 (RvD1), a naturally occurring anti-inflammatory and pro-resolving lipid molecule is able to affect the TRP channel activation.

EXPERIMENTAL APPROACH

We examined the effect of RvD1 on the six thermoTRPs using Ca(2+) imaging and whole cell electrophysiology experiments using the HEK cell heterologous expression system, cultured sensory neurons and HaCaT keratinocytes. We also checked changes in agonist-specific acute licking/flicking or flinching behaviours and TRP-related mechanical and thermal pain behaviours using Hargreaves, Randall-Selitto and von Frey assay systems with or without inflammation.

KEY RESULTS

RvD1 inhibited the activities of TRPA1, TRPV3 and TRPV4 at nanomolar and micromolar levels. Consistent attenuations in agonist-specific acute pain behaviours by immediate peripheral administration with RvD1 were also observed. Furthermore, local pretreatment with RvD1 significantly reversed mechanical and thermal hypersensitivity in inflamed tissues.

CONCLUSIONS AND IMPLICATIONS

RvD1 was a novel endogenous inhibitor for several sensory TRPs. The results of our behavioural studies suggest that RvD1 has an analgesic potential via these TRP-related mechanisms.

Guillain-Barré syndrome following receipt of influenza A (H1N1) 2009 monovalent vaccine in Korea with an emphasis on Brighton Collaboration case definition

BACKGROUND

In 2009-2010 season, with ongoing of influenza A (H1N1), employment of mass vaccination has generated concerns in issue of adverse events following immunization (AEFI). This study investigates the clinical and laboratory data of reported cases of Guillain-Barré syndrome (GBS) and Fisher syndrome (FS) following receipt of influenza A (H1N1) 2009 monovalent vaccine to the National Vaccine Injury Compensation Program (NVICP) in Korea, with all cases reviewed under case definition developed by Brighton Collaboration GBS Working Group.

METHOD

Retrospective review of medical records for all suspected cases of GBS ad FS following receipt of influenza A (H1N1) monovalent vaccine reported to NVICP from December 1, 2009, through April 28, 2010 was conducted. Additional analyses were performed for identification of levels of diagnostic certainty according to Brighton Collaboration case definition.

RESULT

Of 29 reported cases, 22 were confirmed to meet Brighton criteria level 1, 2, or 3 for GBS (21) or FS (1). Of those, 2 (9.1%) met level 1, 9 (40.9%) met level 2, and 11 (50.0%) met level 3. The male to female ratio was 2:0 in cases with level 1, 8:1 in cases with level 2, and 3:8 in cases with level 3. The mean age was older in cases with level 1 (54.0 ± 26.9) than that of cases with level 2 (25.6 ± 22.8), and level 3 (13.6 ± 2.4, P=0.005). The median onset interval was longer in cases with level 1 (16 days) than that of cases that met level 2 (12.44 days), and 3 (1.09 days, P=0.019).

CONCLUSION

The Brighton case definition was used to improve the quality of AEFI data in Korea, and was applicable in retrospective review of medical records in cases with GBS and FS after influenza A (H1N1) vaccination. These findings suggest that standardized case definition was feasible in clarifying the AEFI data, and to further increase the understanding of possible relationship of influenza vaccine and GBS.

Active surveillance of adverse events following immunization against pandemic influenza A (H1N1) in Korea

Surveillance of vaccine safety is one of the public health interventions used to investigate the causal relationship between vaccines and adverse events. Using active surveillance data, we aimed to compile a detailed summary describing the safety of the pandemic influenza A (H1N1) vaccine. Computer-assisted telephone interview was used to investigate adverse events for 9,000 subjects who had received non-adjuvanted vaccines between November 2009 and January 2010, and for 19,000 adults who received adjuvanted vaccines from January through March 2010. The participants were interviewed to obtain information about local and systemic adverse events. Among subjects who received the non-adjuvanted vaccine, 5.5% (n=492) reported adverse events after vaccination, while 6.7% of those who received the adjuvanted vaccine reported adverse events. In the group receiving the adjuvanted vaccine, the highest reported rate of adverse events was among persons aged 19-49 years (9.1%, 577/6,329), followed by persons aged 50-64 years (7.2%, 485/6,718), and elderly persons aged 65 years and over (3.4%, 204/5,953). The implementation of this active surveillance study demonstrated the safety of both the adjuvanted and non-adjuvanted H1N1 vaccines.

Surveillance and control of rubella in the republic of Korea from 2001 to 2009: the necessity for enhanced surveillance to monitor congenital rubella syndrome

OBJECTIVES

The aim of this study was to review the epidemiologic data of rubella and congenital rubella syndrome (CRS) supplied by surveillance systems from 2001 to 2009 and to propose measures to improve the quality of the surveillance system in the Republic of Korea.

METHODS

The epidemiological data for rubella and CRS cases reported to the Korea Centers for Disease Control and Prevention from 2001 to 2009 were retrospectively reviewed, and insurance reimbursement data from the Korea National Health Insurance Review Agency were collected for comparison.

RESULTS

The number of yearly reported rubella cases to the Korea Centers for Disease Control and Prevention from 2001 to 2009 was 128, 24, 8, 24, 15, 12, 35, 30, and 36, respectively. The occurrence of rubella shifted to a slightly higher age group during the 9-year period, i.e. from 0-9 years to 10-19 years. Among the 309 reported rubella cases, three were confirmed cases of CRS. In addition, according to data sourced from Health Insurance Review Agency, 24, 19, 19, 9, and 5 CRS cases were reported for medical insurance reimbursement from 2005 to 2009, respectively.

CONCLUSION

According to available surveillance data, the reported cases of rubella and CRS were not high, but a more detailed surveillance with emphasis on susceptible women of childbearing age is necessary for better monitoring and control of rubella and CRS in the Republic of Korea.

Invasive oral aspergillosis in a patient with acute myeloid leukaemia

Aspergillosis (a fungal infection by an organism of the Aspergillus species) of the oral cavity is an uncommon condition which most frequently occurs in immunocompromised patients, such as those with haematological malignancies. In such patients, prolonged neutropenia secondary to chemotherapeutic agents enables the spread of invasive aspergillosis, which is unaffected by anatomical barriers. Early detection and treatment of the condition is essential to avoid more serious complications, such as disseminated infection, which results in increased morbidity and mortality. This case report describes a patient with acute myeloid leukaemia who developed localized invasive Aspergillus flavus of the palate. High-dose antifungal therapy was instituted along with surgical removal of the involved tissues. Aspergillosis of the palate was successfully eradicated with no long-term ill effects from the treatment. Management of invasive aspergillosis includes early aggressive antifungal medication combined with surgical removal of the involved tissues.

Laser modulation of heat and capsaicin receptor TRPV1 leads to thermal antinociception

Er,Cr:YSGG lasers are used clinically in dentistry. The advantages of laser therapy include minimal thermal damage and the alleviation of pain. This study examined whether the Er,Cr:YSGG laser has in vivo and in vitro antinociceptive effects in itself. In capsaicin-evoked acute licking/shaking tests and Hargreaves tests, laser irradiation with an aerated water spray suppressed nociceptive behavior in mice. Laser irradiation attenuated TRPV1 activation by capsaicin in Ca(2+) imaging experiments with TRPV1-overexpressing cells and cultured trigeminal neurons. Therefore, the laser-induced behavioral changes are probably due to the loss of TRPV1 activity. TRPV4 activity was also attenuated, but limited mechanical antinociception by the laser was observed. The laser failed to alter the other receptor functions, which indicates that the antinociceptive effect of the laser is dependent on TRPV1. These results suggest that the Er,Cr:YSGG laser has analgesic effects via TRPV1 inhibition. Such mechanistic approaches may help define the laser-sensitive pain modality and increase its beneficial uses.