Demonstration of a ring-FEL as an EUV lithography tool

This paper presents the required structure and function of a ring-FEL as a radiation source for extreme ultraviolet radiation lithography (EUVL). A 100 m-long straight section that conducts an extremely low emittance beam from a fourth-generation storage ring can increase the average power at 13.5 nm wavelength to up to 1 kW without degrading the beam in the rest of the ring. Here, simulation results for a ring-FEL as a EUVL source are described.

69 Cloned bovine embryonic development derived from interferon tau knockout cells

Interferon tau (IFNT), a type I interferon, is known as a key signal molecule during pregnancy in ruminants because of the necessity in maternal recognition of pregnancy. It is produced in trophectoderm cells of the elongation bovine conceptus at Day 13-21, and peak production is at Day 15 to 17 of pregnancy. In addition, other studies show that it can affect embryonic development and quality. In this study, the effect of IFNT knockout in donor cells to bovine cloned embryonic development by somatic cell nuclear transfer (SCNT) was investigated. To proceed with this experiment, immature oocytes from ovaries at a local slaughterhouse were matured in vitro for 22h. To prepare the donor cell with IFNT knockout, somatic cells were transfected with Cas9 and single guide RNA targeting IFNT, and several single derived colonies with high proliferation were isolated for mutation assay. Finally, one colony that had mono-allelic mutation (4bp deletion) was selected and used as the donor cell for SCNT. A donor cell was injected into an enucleated oocyte. Reconstructed oocytes with the donor cell were fused by electrical shock, activated by chemical stimulation, and cultured for 7 days in chemically defined medium. For this study, control (n=94) and IFNT knockout groups (n=140) were compared with 4 replications. The results showed no significant difference between control and IFNT knockout groups not only in cleavage rate, but also in blastocyst formation rate (control: 15.7±8.3%, IFNT knockout group: 26.3±13.1%). In addition, the number of blastocyst cell was not different between control (88.2±27.0) and IFNT knockout group (88.0±21.1). Some IFNT mutated blastocysts from SCNT were randomly selected for confirmation of the deletion of IFNT, and all samples were positive for mutation. In conclusion, these data demonstrated that the disruption of IFNT did not affect embryonic development. In future study, we would transfer these embryos and check the effect of IFNT during pregnancy status. This work was supported by BK21 PLUS Program for Creative Veterinary Science, the National Research Foundation of Korea (2017R1A2B3004972), and the Technology Development Program (S2566872) by MSS.

82 Disruption of p53 in bovine somatic cells affected cloned embryonic development

The p53 gene is a tumour suppressor gene with many roles in cellular reprogramming, senescence, or cancers. Knockdown of p53 in somatic cells improves generation of induced pluripotent stem cells and developmental competence of cloned embryos. In this study, we hypothesised that disruption of p53 in bovine somatic cells using CRISPR-Cas9 may improve reprogramming and result in increased blastocyst formation. For the study, ovary-derived immature bovine cumulus-oocyte complexes were matured in vitro. To prepare the donor cells with disruption of p53, primary cells from the skin tissue were transfected with spCas9 and single guide RNA for bovine p53. Two days later, genomic DNA was extracted and the mutation was evaluated on the target region using the T7E1 enzyme. Several single cell colonies were isolated to investigate the mutation and sequencing for mutation positive colonies was performed. One colony with high proliferative activity and heterozygotic mutation (−7bp deletion) was selected and used as the donor cell for somatic cell nuclear transfer. The donor cell was microinjected into an enucleated oocyte. Reconstructed oocytes were fused by electrical pulse, activated by chemical stimulation, and cultured in chemically defined media for 7 days at 5% CO2 and 5% O2. Data were subjected to ANOVA and least significant different test to determine differences between experimental groups by using SAS software (SAS Institute Inc., Cary, NC, USA). Statistical significance was determined when the P-value was less than 0.05. Blastocyst formation rate (13.5±7.6%) from the mutated cell line was significantly lower than wild type cells (43.9±12.1%). Moreover, total cell number (115.4±13.3) of the blastocysts from knockout cells was significantly decreased compared with the control group (143.6±22.5). Some randomly selected blastocysts derived from mutated cells were subjected to mutation assay to confirm deletion of p53. As expected, all the samples were positive to mutation. These data did not support our hypothesis that p53 disruption could improve blastocyst formation competence of bovine cloned embryos. In the future, the reason for impaired embryonic development of clones of p53 deleted somatic cells will be further investigated. This work was supported by BK21 PLUS Program for Creative Veterinary Science, the National Research Foundation of Korea (2017R1A2B3004972), and the Technology Development Program (S2566872) by MSS.

Usefulness of Combined PET/CT to Assess Regional Lymph Node Involvement in Gastric Cancer

Aims and Background

The aim of this study was to evaluate the value of positron emission tomography/computed tomography (PET/CT) for preoperative staging of gastric cancer and to compare the diagnostic performance of PET/CT with that of contrast-enhanced computed tomography (CECT).

Methods

We retrospectively reviewed 74 gastric cancer patients who underwent preoperative PET/CT and CECT, and subsequent curative surgical resection between April 2007 and July 2011. Preoperative PET/CT and CECT images for primary tumors of the stomach and lymph node metastases were reviewed retrospectively. The final diagnoses of primary tumors and LN metastases were based on histopathological specimens in all patients.

Results

Advanced gastric cancer was present in 65% of patients (n = 48), and the remaining patients had early gastric cancer (n = 26). Sixteen patients (22%) showed signet-ring-cell histology. For the detection of the primary tumor, the sensitivity of PET/CT was significantly higher than that of CECT (67% vs 55%, respectively; P = 0.049). For the evaluation of regional lymph node metastasis, the sensitivity, specificity, and accuracy of PET/CT and CECT were 34% and 51% (P = 0.065), 88% and 79% (P = 0.687), and 58% and 64% (P = 0.332), respectively. Neither PET/CT nor CECT detected regional lymph node metastases in early gastric cancer patients. Signet-ringcell histology showed trends of non-FDG-avid lymph node metastases (odds ratio = 0.15, 95% confidence interval 0.17–1.37, P = 0.093)

Conclusions

The accuracy of PET/CT is low and it is not a useful tool in the staging of gastric cancer overall in early gastric cancer and in signet-ring-cell carcinoma. Furthermore, the sensitivity of PET/CT could be inferior to that of CECT in the diagnosis of regional lymph node metastasis.

197 The Effect of Gonadotropin-Releasing Hormone Agonist on Superovulation and Estrous Synchronization in Female Sprague Dawley Rat

A large number of oocytes and adequate recipient conditions are required to produce genetically modified rats by embryo transfer. In this study, we investigated the effect of a synthetic gonadotropin-releasing hormone (GnRH) agonist, buserelin, on (1) superovulatory response in donor rats, and (2) oestrous cycle synchrony in recipient female Sprague Dawley rats at 8 weeks of age. First, for superovulation, donors were divided into 2 groups: control and buserelin injection group (42 μg mL−1). Superovulation was performed in both groups by injection of pregnant mare’s serum gonadotropin (PMSG, 150 IU) at Day −3 and human chorionic gonadotropin (hCG, 150 IU) at Day −1 (Day 0 = oocyte collection). In addition, the buserelin group was given 42 μg mL−1 buserelin on Day −4. Oviduct and ampulla were removed surgically to collect the oocytes. As results, more ovulations were detected in the 42 μg mL−1 buserelin group (6.18 ± 1.10 oocyte/rat, n = 240) than in the control group (5.06 ± 0.82 oocyte/rat; n = 124; t-test P = 0.038). Second, 2 groups were set up to investigate the effect of administration of buserelin on synchronizing the oestrus cycle of recipients. Because the oestrous cycle of the rat was 4 to 5 days, we examined the difference of vaginal impedance between the 2 groups on Day 4 after injection and checked whether there was a significant difference in the synchronization of the oestrous cycle. An impedance value >3.0 kΩ was considered as an indication for proestrus stage; therefore, we analysed the data >3.0 kΩ in both groups. In results, the incidence of proestrus was significantly increased in buserelin injection group (n = 128) than in the control group (n = 70). In addition, there was a significant difference in mean impedance in the 2 groups (buserelin injection group: 4.25 ± 3.79 kΩ; control group: 1.43 ± 1.20 kΩ; P < 0.005). In conclusion, administration of 42 μg mL−1 buserelin had a beneficial effect on oocyte ovulation and oestrous synchronization, and it will be usefully applied in the production of transgenic rats.

204 Blood Analysis of Cas9-Expressing Cattle

The CRISPR/Cas9 system has proved to be a powerful tool for knockout and knock-in in various species. When 2 components—Cas9 and single guide (sg)RNA—are delivered into cells or embryos, the events of gene editing occur. Because Cas9 is essential for gene editing in the CRISPR/Cas9 system, some studies have reported the production of Cas9-expressing animals, such as mice, which could be used to increase gene editing efficiency in subsequent experiments. In previous reports, we successfully produced 4 Cas9-expressing cattle via microinjection (Hahn et al. 2016 Reprod. Fertil. Dev. 29, 211). Primary cells from these calves had Cas9 activity because transfection of only sgRNA resulted in gene deletion. The aim of this study was to analyse the blood of the transgenic cattle to investigate the effect of Cas9 expression on health. Two of 4 transgenic calves died; one had severe ruminant tympany, failed to respond to treatment, and died at 4 months of age, and the other died at 5 months of age due to accidental ingestion of a needle from a feed bunk. Blood samples were obtained from the surviving 2 transgenic cattle (1 male and 1 female) at 7 and 12 months for blood analysis. Five milliliters of whole blood samples was collected from the jugular vein. Portions were used for CBC (Hemavet 950, Drew Scientific, Miami Lakes, FL, USA) and for serum chemistry analysis (BS-400, Mindray, Shenzhen, China). Average values for white blood cells (9600 and 1057/mm3), neutrophils (4590 and 3870/mm3), lymphocytes (4020 and 5910/mm3), red blood cells (732,000 and 798,000/mm3), hemoglobin (9.5 and 10.2 g dL−1), packed cell volume (24.3 and 25.3%), platelet (439,000 and 327,500/mm3), AST (76 and 104 IU), ALP (140 and 133 IU), BUN (7.5 and 10.5 mg dL−1), and creatinine (1.3 and 1.0 mg dL−1) of male and female transgenic calves were within the reference range. Additionally, there was no difference in general health information, including body temperature and feeding. In conclusion, we demonstrated that continuous Cas9 expression in transgenic cattle did not affect health status of the surviving calves in terms of blood analysis. They have grown up without any health issues and are currently 14 (female) and 15 (male) months old. In the near future, we will evaluate their germline transmission by natural breeding or in vitro fertilization. This work was supported by BK21 PLUS Program for Creative Veterinary Science, NRF (NRF-2017R1A2B3004972), and Seoul Milk Coop (SNU 550–20160004).

Prevalence, complete genome sequencing and phylogenetic analysis of porcine deltacoronavirus in South Korea, 2014-2016

Porcine deltacoronavirus (PDCoV) is a newly emerged enterotropic swine coronavirus that causes enteritis and diarrhoea in piglets. Here, a nested reverse transcription (RT)‐PCR approach for the detection of PDCoV was developed to identify and characterize aetiologic agent(s) associated with diarrhoeal diseases in piglets in South Korea. A PCR‐based method was applied to investigate the presence of PDCoV in 683 diarrhoeic samples collected from 449 commercial pig farms in South Korea from January 2014 to December 2016. The molecular‐based survey indicated a relatively high prevalence of PDCoV (19.03%) in South Korea. Among those, the monoinfection of PDCoV (9.66%) and co‐infection of PDCoV (6.30%) with porcine epidemic diarrhoea (PEDV) were predominant in diarrhoeal samples. The full‐length genomes or the complete spike genes of the most recent strains identified in 2016 (KNU16‐07, KNU16‐08 and KNU16‐11) were sequenced and analysed to characterize PDCoV currently prevalent in South Korea. We found a single insertion‐deletion signature and dozens of genetic changes in the spike (S) genes of the KNU16 isolates. Phylogenetic analysis based on the entire genome and spike protein sequences of these strains indicated that they are most closely related to other Korean isolates grouped with the US strains. However, Korean PDCoV strains formed different branches within the same cluster, implying continuous evolution in the field. Our data will advance the understanding of the molecular epidemiology and evolutionary characteristics of PDCoV circulating in South Korea.

205 PRODUCTION OF Cas9-EXPRESSING CATTLE USING DNA TRANSPOSON

A genome-editing technology, CRISPR/Cas9 system is proved to be a powerful tool for knockout and knock-in in various species. When 2 components [Cas9 and single guide (sg) RNA] are delivered into cells or embryos, the events of gene editing occur. Because Cas9 is essential for every gene editing based on the CRISPR/Cas9 system, some studies reported that efficiency of gene editing would be increased as Cas9 was integrated into cells or animals. Accordingly, if the Cas9-expressing cattle is born, it would be broadly used for gene editing in cattle. For this study, the Cas9 and RFP genes were cloned into the PiggyBac transposon system. PiggyBac-Cas9-RFP and transposase were microinjected into 1436 IVF embryos and 241 blastocysts were formed. Blastocysts with RFP expression accounted for 14.1% of total formed blastocysts. Five blastocysts were selected and transferred into 5 recipient cow (1 embryo per recipient). After gestation periods, 4 transgenic cattle were delivered without any veterinary assistance. From transgenic cattle, ear skin tissue was collected for primary culture. On those primary cells, sgRNA in DNA form for various genes such as PRNP, RB1, and BLG were transfected with 2 μg of sgRNA per 5 × 105 cells using electroporation. As expected, every group of each sgRNA delivered was confirmed to be mutated by T7E1 assay. The data demonstrated that, for the first time, transgenic cattle with Cas9 expression were born, grown up to date (age = 5 months) and will be a valuable resource for genome editing in cattle. This work was supported by BK21 PLUS Program for Creative Veterinary Science and Seoul Milk Coop (SNU 550–20160004).

204 POTENTIAL OF GREEN FLUORESCENT PROTEIN LOCUS FOR GENE EDITING IN DNA TRANSPOSON-PRODUCED TRANSGENIC CATTLE

Recently, we published on the efficient production of transgenic cattle using the DNA transposon system (Yum et al. 2016 Sci. Rep. 6, 27185). In that study, 8 transgenic cattle were born following transposon-mediated gene delivery system (Sleeping Beauty and Piggybac transposon) via microinjection of zygotes. In the analysis of their genomic stability using next-generation sequencing, there was no significant difference in the number of genomic variants between transgenic and nontransgenic cattle. In this study, we have described current status of those transgenic cattle in term of health, germ-line transmission, and application. All the transgenic cattle have grown up to date (the oldest being 30 months old, the youngest being 12 months old) without any health issue. In general blood analysis, there were not any significant changes between transgenic cattle and wild type. Because the transgene (green fluorescent protein; GFP) expression is constitutively active and has strong expression, it could be visualised without fluorescence equipment. One of transgenic male cattle reached puberty and semen was collected. Over 200 frozen semen straws were produced and some were used for IVF. In every IVF replication, around 80% blastocysts expressed the GFP. Over 36 GFP blastocysts were frozen for embryo transfer in the future, and we are planning to crossbreed for generating homozygotic transgenic cattle. Another application is to use the GFP locus to gene-edit the transgenic cattle, as long-term expression of transgene did not affect their health. In 1 cell stage, embryos produced using GFP frozen-thawed semen, single guide RNA for GFP, Cas9, together with donor DNA that included RFP and homology arms to link the double-strand break of single guide RNA target site, were co-injected and RFP was observed. Knockout/-in for editing GFP locus using CRISPR-Cas9 might be a valuable approach for the next generation of transgenic models by microinjection. In conclusion, we demonstrated that transgenic cattle via transposon are healthy to date and germ-line competence was confirmed. The GFP locus will be used as the target region for future gene engineering via genome-editing technology. Finally, all those animals could be a valuable agricultural and veterinary science resource for studying the effects of gene manipulation on disease resistance and food production. This work was supported by BK21 PLUS Program for Creative Veterinary Science and Seoul Milk Coop (SNU 550–20160004).

Longitudinal follow-up of quality of life in gastrointestinal cancer patients after curative surgery in South Korea

697

Background: Early detection of cancer and improved treatment have led to higher survival rates and an increasing number of long-term survivors in oncology practice. But there are few longitudinal Quality of Life (QoL) studies in patients who experienced cancer surgery. To investigate the longitudinal change in QoL of elderly gastrointestinal cancer patients, we designed prospective study for QoL in resected gastrointestinal cancer patients. Methods: A prospective longitudinal cohort study was designed. Patients from Hallym, Ajou, and Samsung medical center in South Korea were enrolled consecutively from February to September of 2012. Patients over 55 years old who received curative resection due to gastrointestinal cancer were included. They were given questionnaires every 6 months since then, and we’ve been using EORTC QLQ C-30 as quality of life scale. We selected patients using propensity score matching(PSM). The mean scores of the patients completing the interview at the 3 time points were compared using mixed model. Results: A total of 353 patients with gastrointestinal cancer were interviewed at baseline. We dichotomized patients into 2 groups ( < 70 years old vs. > = 70 years old). There were significant difference in ECOG performance status between 2 groups. After balancing with PSM, we selected 272 patients. Overall QoL did not show significant difference between 2 groups at baseline interview. After repeated interview, the score of global health status, physical functioning, and pain showed significantly higher in younger group ( < 70 years old). But other items didn't show significant difference.Especially patients in both group felt financial difficulty increased. Conclusions: Although the elderly gastrointestinal cancer patients showed lower score in global health status, physical function, they preserved relatively well in other functional status after curative surgery. Most patients felt increased financial burden.

Randomized phase 2 trial of S1 and oxaliplatin-based chemoradiotherapy with or without induction chemotherapy for esophageal cancer

PURPOSE

To assess, in a randomized, phase 2 trial, the efficacy and safety of chemoradiotherapy with or without induction chemotherapy (ICT) of S1 and oxaliplatin for esophageal cancer.

PATIENTS AND METHODS

Patients with stage II, III, or IVA esophageal cancer were randomly allocated to either 2 cycles of ICT (oxaliplatin 130 mg/m(2) on day 1 and S1 at 40 mg/m(2) twice daily on days 1-14, every 3 weeks) followed by concurrent chemoradiotherapy (CCRT) (46 Gy, 2 Gy/d with oxaliplatin 130 mg/m(2) on days 1 and 21 and S1 30 mg/m(2) twice daily, 5 days per week during radiation therapy) and esophagectomy (arm A), or the same CCRT followed by esophagectomy without ICT (arm B). The primary endpoint was the pathologic complete response (pCR) rate.

RESULTS

A total of 97 patients were randomized (arm A/B, 47/50), 70 of whom underwent esophagectomy (arm A/B, 34/36). The intention-to-treat pCR rate was 23.4% (95% confidence interval [CI] 11.2-35.6%) in arm A and 38% (95% CI 24.5% to 51.5%) in arm B. With a median follow-up duration of 30.3 months, the 2-year progression-free survival rate was 58.4% in arm A and 58.6% in arm B, whereas the 2-year overall survival rate was 60.7% and 63.7%, respectively. Grade 3 or 4 thrombocytopenia during CCRT was more common in arm A than in arm B (35.4% vs 4.1%). The relative dose intensity of S1 (89.5% ± 20.6% vs 98.3% ± 5.2%, P=.005) and oxaliplatin (91.4% ± 16.8% vs 99.0% ± 4.2%, P=.007) during CCRT was lower in arm A compared with arm B. Three patients in arm A, compared with none in arm B, died within 90 days after surgery.

CONCLUSIONS

Combination chemotherapy of S1 and oxaliplatin is an effective chemoradiotherapy regimen to treat esophageal cancer. However, we failed to show that the addition of ICT to the regimen can improve the pCR rate.

209 CLONED EMBRYONIC DEVELOPMENT AND GENE EXPRESSION OF SPONTANEOUSLY IMMORTALIZED PORCINE SKIN FIBROBLASTS

Immortalization of somatic cells by oncogenes is effective for evaluation of gene targeting tools or molecular cell pathway because of relatively longer life span than normal cells. The BMI1 gene has been used to immortalize human and murine somatic cells, and we confirmed that BMI1 increased cell-life span of porcine skin fibroblasts and had no detrimental effect on pre-implantational development after somatic-cell nuclear transfer (SCNT; unpublished data). Here, we report a primary cell-line which was spontaneously immortalized without transduction of any additional gene. The minipig skin fibroblasts (passage 3 after primary culture) were divided into two parts, one group was electroporetically transfected with pCAG-BMI1-T2A-RFP plasmids (BC1) and the other had no treatment (CC1). To establish the single-cell-originated cell-lines, cells of each group were plated in 100-mm dishes at 100 cells/dish and well-formed colonies were picked up after 2 weeks. These colonies were expanded until they were fully confluent in 100-mm dishes (designated Passage 0) and then, the cell were maintained with DMEM (20% FBS) at 3 × 105 cells/60 mm dish. Population doubling time was checked every 5 passages until Passage 45 (sub-cultured during ~160 days) by calculation of cells that had been plated in 12-well plates at 4 × 104 cells/well. The expressions of p16, p21, and DNMT3b genes were determined by RT-qPCR at early (Passage 5) and late (Passage 45) stage. Also, SCNT (Song et al. 2009 Mol. Reprod. Dev. 76, 611–619) embryos using cells of early and middle (Passage 35) stage were evaluated in terms of reprograming efficiency. Data were analysed by t-test (Prism version 5.01, GraphPad Software, La Jolla, CA, USA). While the mean doubling time of BC1 was 25.3 h until Passage 40 and drastically increased at Passage 45 (81.7 h), that of CC1 was maintained until Passage 45 (mean 38.3 h). Expression of p16 in CC1 was significantly higher than that in BC1 at all stages. However, in late stage CC1, p21 expression was significantly lower than other groups and DNMT3b expression was increased. In SCNT embryos, the rate of blastocysts with early stage CC1 (18.3%) was not different from that of early stage BC1 (19.9%). And, although the rates of SCNT blastocyst derived from middle stage cells were decreased than those of early stage cells, there was no difference between BC1 and CC1 (6.6% and 5.4%, respectively). In karyotyping, while BC1 was trisomy of chromosome 14 only in late stage, CC1 had an isochromosome in chromosome 17 from early stage and an additional part was attached in chromosome 11 at late stage CC1. In summary, spontaneously immortalized skin fibroblasts could maintain the cell-life span by down-regulating the p21 expression and the pre-implantational development after SCNT was not different from that of BMI1-immortalized cells. And, additional studies are needed to confirm whether the chromosomal abnormality influences the expression of other genes related with cell cycle or senescence.This study was supported by NRF-2013R1A1A2010766, IPET (#311011-05-3-SB010), the Research Institute for Veterinary Science, and the BK21 plus program.

Optimizing electrical activation of porcine oocytes by adjusting pre- and post-activation mannitol exposure times

Modifying electrical activation conditions have been used to improve in vitro embryo production and development in pigs. However, there is insufficient information about correlations of porcine embryo development with oocyte pre- and post-activation conditions. The purpose of this study was to compare the developmental rates of porcine oocytes subjected to different mannitol exposure times, either pre- or post-electrical activation, and to elucidate the reason for the optimal mannitol exposure time. Mannitol exposure times around activation were adjusted as 0, 1, 2 or 3 min. Blastocyst development were checked on day 7. Exposure of oocytes to mannitol for 1 or 2 min before electrical activation produced significantly higher blastocyst rates than exposure for 0 or 3 min. There was no significant difference in blastocyst rates when activated oocytes were exposed to mannitol for 0, 1, 2 or 3 min after electrical activation. While exposure of oocytes to mannitol for 1 min pre- and 3 min post-activation showed significantly higher blastocyst development than 0 min pre- and 0 min post-activation. It also showed higher maintenance of normal oocyte morphology than exposure for 0 min pre- and 0 min post-activation. In conclusion, exposure of oocytes to mannitol for 1 min pre- and 3 min post-activation seems to be optimal for producing higher in vitro blastocyst development of porcine parthenogenetic embryos. The higher blastocyst development is correlated with higher maintenance of normal morphology in oocytes exposed to mannitol for 1 min pre- and 3 min post-activation.

Usefulness of combined PET/CT to assess regional lymph node involvement in gastric cancer

AIMS AND BACKGROUND

The aim of this study was to evaluate the value of positron emission tomography/computed tomography (PET/CT) for preoperative staging of gastric cancer and to compare the diagnostic performance of PET/CT with that of contrast-enhanced computed tomography (CECT).

METHODS

We retrospectively reviewed 74 gastric cancer patients who underwent preoperative PET/CT and CECT, and subsequent curative surgical resection between April 2007 and July 2011. Preoperative PET/CT and CECT images for primary tumors of the stomach and lymph node metastases were reviewed retrospectively. The final diagnoses of primary tumors and LN metastases were based on histopathological specimens in all patients.

RESULTS

Advanced gastric cancer was present in 65% of patients (n = 48), and the remaining patients had early gastric cancer (n = 26). Sixteen patients (22%) showed signet-ring-cell histology. For the detection of the primary tumor, the sensitivity of PET/CT was significantly higher than that of CECT (67% vs 55%, respectively; P = 0.049). For the evaluation of regional lymph node metastasis, the sensitivity, specificity, and accuracy of PET/CT and CECT were 34% and 51% (P = 0.065), 88% and 79% (P = 0.687), and 58% and 64% (P = 0.332), respectively. Neither PET/CT nor CECT detected regional lymph node metastases in early gastric cancer patients. Signet-ring-cell histology showed trends of non-FDG-avid lymph node metastases (odds ratio = 0.15, 95% confidence interval 0.17-1.37, P = 0.093).

CONCLUSIONS

The accuracy of PET/CT is low and it is not a useful tool in the staging of gastric cancer overall in early gastric cancer and in signet-ring-cell carcinoma. Furthermore, the sensitivity of PET/CT could be inferior to that of CECT in the diagnosis of regional lymph node metastasis.

21 SITE-SPECIFIC RECOMBINATION USING Dre-RECOMBINASE IN PORCINE CELLS AND EMBRYOS

Site-specific recombinases (SSR), such as Cre and Flp recombinases, which enable DNA excision, insertion, and translocation, have been used for conditional target gene expression in mouse and other vertebrates. In this study, we evaluated another SSR, Dre-recombinase (Dre), which is functionally similar to Cre recombinase in porcine fibroblasts and embryos. For this study, 2 fragment DNA constructs (rox GFP-polyA and rox RFP-polyA) were combined with piggybac transposition expression vector (Kim et al. 2011 J. Vet. Med. Sci.) using a multisite gateway cloning system (MultiSite Gateway® Pro, Invitrogen, Carlsbad, CA, USA). The expression vector carrying rox-flanked green fluorescent protein (GFP) followed by red fluorescent protein (RFP) and transposase were transfected into kidney-derived porcine cells by nucleofection (Neon® Transfection System, Invitrogen). A GFP-expressing cell line, which was not expressing RFP, was established. And then rox-flanked GFP were removed by Dre transfection and RFP was expressed in the kidney cells. At the cellular level, this excision was confirmed by site-specific RT-PCR and sequencing. The rox-flanked GFP cells were reconstructed with enucleated oocytes and then the cloned embryos were cultured in porcine zygote medium-5. Dre was micro-injected into 1 of the 2-cell-stage blastomeres. After 6 days, RFP expression was observed on the part of embryos after microinjection. In conclusion, the data demonstrated that, like other SSR, Dre might be applied in conditional target gene expression for generating porcine biomedical models.

28 TREATMENT WITH SUBEROYLANILIDE HYDOXAMIC ACID OR SODIUM BUTYRATE ON PORCINE SOMATIC CELL NUCLEAR TRANSFER EMBRYOS DERIVED FROM KIDNEY CELLS OF HUMAN HEME OXYGENASE-1 TRANSGENIC PIG

Because somatic cell nuclear transfer (SCNT) is influenced by many factors concerning a series of various steps, the cloning efficiency is low in so many species and it seems to be more serious in production of transgenic (TG) animals. Reprogramming of donor nucleus is one of the important factors that affects the developmental competence of SCNT embryos, and several epigenetic remodelling drugs have been used to improve the cloning efficiency. In this study, we examined the effect of suberoylanilide hydoxamic acid (SAHA) or sodium butyrate (NaBu) treatment on the development of porcine SCNT embryos derived from kidney cells of TG pig. Fully confluent porcine kidney cells expressing the human heme oxigenase-1 gene were used for nuclear donor. For SCNT, matured oocytes with 1st polar body were enucleated, electrically fused, and activated 1 h after fusion (Song et al. 2009 Mol. Reprod. Dev. 76, 611–619). Then, SCNT embryos were incubated in postactivation medium [PA; porcine zygote medium-5 (PZM-5) supplemented with 0.5% dimethyl sulfoxide] for 4 h (control), PA with 0.4 μg mL–1 demecolcine for 4 h (Dc), PA with 0.5 μM SAHA for 9 h (SAHA), or PA with 1 mM NaBu for 9 h (NaBu). After postactivation treatment, SCNT embryos were cultured in fresh PZM-5 for 7 days. The embryos were examined for cleavage and blastocyst formation on Days 2 and 7, respectively (the day of SCNT was designated Day 0). Total cell number of blastocysts was examined by counting the number of nuclei stained with Hoechst 33342 under ultraviolet light. Complementary DNA synthesised with total RNA extracted from blastocysts were used for qRT-PCR to determine HDAC2, HDAC6, and GAPDH gene expression. Data were analysed by one-way ANOVA followed by Tukey's multiple comparison test using GraphPad Prism version 5.01 (Graphpad Software, San Diego, CA, USA). The cleavage rates (77.0–82.9%) of treated embryos were not different from that of control embryos (79.0%). Blastocyst formation was slightly increased in Dc- (36/132, 27.3%), SAHA- (34/125, 28.6%), and NaBu- (36/133, 27.3%) treated embryos than in control embryos (32/128; 25.0%), but the difference was not significant. Total cell numbers (45.2–47.5) of treated embryos were not different from that of control embryos (51.8). Expression of HDAC2 was higher in SAHA-treated embryos than in control and Dc-treated embryos (P < 0.05), but it was not different from that of NaBu-treated embryos. The relative expression of HDAC6 transcript was increased in SAHA- and NaBu-treated embryos, but there was no significant difference among all groups. Although SAHA or NaBu did not improve the pre-implantational development of porcine SCNT embryos derived from kidney cells of TG pig as assessed in this study, additional studies are needed to determine the effect of SAHA or NaBu on gene expression of pig TG embryos and developmental competency following embryo transfer according to the origin of donor cells. This study was supported by IPET (#311011-05-2-SB010), MOTIE (#10033839-2012-21) and the TS Corporation.

A Phase II Study to Evaluate the Efficacy of Ramosetron, Aprepitant, and Dexamethasone in Preventing Cisplatin-Induced Nausea and Vomiting in Chemotherapy-Naïve Cancer Patients

Purpose

Combination therapy with aprepitant, serotonin receptor antagonist, and steroids improves the complete response rate of both acute and delayed chemotherapy-induced nausea and vomiting (CINV). However, it is not known whether ramosetron is suitable for administration in combination with aprepitant. Therefore, we conducted a multicenter, open-label, prospective, phase II study in order to assess the efficacy and tolerability of combination therapy with ramosetron, aprepitant, and dexamethasone (RAD) for prevention of cisplatin-based CINV in chemotherapy-naïve patients with solid cancers.

Materials and Methods

Forty-one patients with various solid cancers (31 male and 10 female; median age, 59 years) who received treatment with highly emetogenic chemotherapy (median cisplatin dose, 70 mg/m²; range 50 to 75 mg/m²) were enrolled in this study. Oral aprepitant (125 mg on day 1; 80 mg on days 2 and 3), intravenous ramosetron (0.6 mg on day 1), and oral dexamethasone (12 mg on day 1; 8 mg on days 2-4) were administered for prevention of CINV.

Results

The complete response (no emesisand retching and no rescue medication) rate was 94.9% in the acute period (24 hours post-chemotherapy), 92.3% in the delayed period (24-120 hours post-chemotherapy), and 92.3% in the overall period (0-120 hours). The absolute complete response (complete response plus no nausea) rate was 74.4% in the acute period, 51.3% in the delayed period, and 46.2% in the overall period. There were no grade 3 or 4 toxicities related to these antiemetic combinations.

Conclusion

RAD regimen is a safe and effective antiemetic treatment for prevention of CINV in patients receiving highly emetogenic chemotherapy.

Species-specific challenges in dog cloning

Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning.

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.

Co-delivery of LETM1 and CTMP synergistically inhibits tumor growth in H-ras12V liver cancer model mice

As hepatocellular carcinoma (HCC) is one of the most common tumors worldwide, development of novel therapeutic approaches for HCC is urgently needed. Two different genes, LETM1 and CTMP, which target mitochondrial functions, were chosen and linked using 2A-peptide sequence. Successful self-cleavage of 2A-peptide induced synergistic antitumor effect in the liver of H-ras12V, the HCC model mice, by simultaneous activation of LETM1 (Leucine zipper/EF hand-containing transmembrane-1) and CTMP (carboxyl-terminal modulator protein). Overexpression of LETM1 and CTMP significantly reduced the incidence of tumorigenesis, which were confirmed by gross and microscopic observations. Morphological changes in mitochondria, such as swelling and loss of cristae, were significant, and the prolonged activation of defects in mitochondrial function led to mitochondria-mediated apoptosis. Furthermore, with CTMP as a direct binding partner of Akt1, and LETM1 as a binding partner of CTMP, LETM1-2A-CTMP downregulated the Akt1 pathway at both Ser473 and Thr308 sites of phosphorylation. Proliferation and angiogenesis, which are important in cancer prognosis, were reduced in tumor sites after introduction of LETM1-2A-CTMP. Taken together, the results indicate that introduction of the mitochondria-targeting genes, LETM1 and CTMP, and self-processing capacity of 2A-peptide sequence exerts an antitumor effect in liver of H-ras12V mice, suggesting its potential as a tool for gene therapy.

42 EFFECT OF S-ADENOSYLHOMOCYSTEINE, A NON-TOXIC EPIGENETIC MODIFYING REAGENT, ON PORCINE FEMALE DONOR CELLS AND CLONED EMBRYOS

Despite great advances in the field of cloning techniques, the efficiency of production of cloning animals is very low. Maybe the poor outcome of somatic cell nuclear transfer (SCNT) is thought to be a consequence of incomplete reprogramming of the donor cell or cloned embryos. The objective of this study was to investigate the effects of treatment with S-adenosylhomocysteine (SAH), the reversible nontoxic inhibitor of DNA methyltransferases (DNMT), on porcine female fibroblast donor cells and in vitro development of cloned embryos. We hypothesized that SAH targeting DNA methylation could alter chromatin configuration and turn it more amenable to reprogramming. Thus, the female fibroblast donor cells were cultured in media containing respective concentrations of SAH [0 (control), 0.1, 0.5, and 1 mM) for 2 passages. One-way ANOVA was used to determine significant differences in the data and a Tukey test was done to determine statistical differences among groups. Compared with nontreated controls, the cells treated with SAH, especially 1 mM, revealed significantly (P < 0.05) reduced global DNA methylation, proved by commercial kit and immunocytochemistry analysis, and elevation of transcript levels for X chromosome-linked genes (XIST and HPRT), estimated by real-time PCR analysis compared with the control group. It was suggested that treatment with SAH in female cells could make cells into more valuable donor cells for cloning. In another trial, cloned embryos using normal donor cells were cultured in media containing 1 mM SAH for 0 (control), 12, and 24 h after activation on different time interval of DNMT inhibition, transferred to PZM5 media, and subsequently cultured for 7 days. Treatment with SAH for 12 h resulted in 13.0 ± 1.9% blastocyst production, which was significantly greater than cloned embryos treated with SAH for 24 h (11.2 ± 2.1%) and control cloned embryos (9.1 ± 1.2%). It was suggested that the appropriate DNMT inhibition might have an important role in in vitro development of porcine SCNT, and improving effects on developmental competency of cloned embryos. We concluded that SAH induced global DNA demethylation that partially reactivated the X chromosome and that a hypomethylated genome may facilitate the nuclear reprogramming process. This study was supported by IPET (no. 311011-05-1-SB010), MKE (no. 10033839-2012-21), Institute for Veterinary Science, the BK21 program, and TS Corporation.

143 EFFECTS OF BOAR SEMINAL PLASMA IN IN VITRO CULTURE OF PORCINE EMBRYOS

Seminal plasma consisting of carbohydrates, proteins, and lipids not only serves as a nutritive and protective medium for sperm cells but also play a pivotal role in inducing the tolerance to pre-existing immune cells as well as improving the intra-uterine conditions for implantation of fertilized embryos (Guerin et al. 2009 Hum. Reprod. Update 15, 517–535). However, the effects of seminal plasma in in vitro culture of fertilized embryos are unknown. In the present study, the seminal plasma was separated from the second fraction of a normal farm boar (n = 1) by centrifugation and filtered seminal plasma was stored at –30°C until use. In a preliminary experiment, the optimal activity of seminal plasma was evaluated by incubating the embryos for different time intervals. To investigate the developmental rates, electrically (EA) (triplicates, n = 490) or chemically (CA) (quintuplicates, n = 599) activated 2-day-old porcine embryos were incubated for 3 h in PZM-5 medium (Funakoshi Co., Tokyo, Japan, Catalog no. IFP0410P) containing 0% (EA: n = 122 and CA: n = 152), 0.1% (EA: n = 123 and CA: n = 148), 0.5% (EA: n = 122 and CA: n = 150), or 1% (EA: n = 123 and CA: n = 149) seminal plasma. Similarly, the developmental rate of chemically activated 2-day-old somatic cell nuclear transferred porcine embryos (quadruplicates, n = 239) was studied after incubation with 0% (n = 119) or 0.1% (n = 120) seminal plasma for 3 h. A significant difference was noticed only in the rate of blastocyst formation in the chemically activated embryos treated with 0.1% seminal plasma (31.7 v. 24.8% in the 0% group, ANOVA; P < 0.05; Prism5, GraphPad Software Inc., La Jolla, CA, USA). None of the treatments showed a significant effect on the cleavage rate and cell numbers of blastocysts. In conclusion, the seminal plasma did not show any harmful effect on early embryos development. Furthermore, the seminal plasma (0.1%) improved the rate of blastocyst formation among the chemically activated nuclear transferred embryos. The results of this preliminary study suggest that the addition of seminal plasma during embryo transfer could increase the rate of pregnancy in pig. This study was supported by MKE (#10033839-2012-21), IPET (#311011-05-1-SB010), the Research Institute for Veterinary Science, and TS Corporation.

283 GENERATION AND CHARACTERIZATION OF BOVINE INDUCED PLURIPOTENT STEM CELLS

Stem cells in large animals are an excellent model for cell therapy research and fine resources for producing transgenic animals. However, there are only few reports of stem cells in large animals because of technical differences between species. In this report, we successfully generate bovine induced pluripotent stem cells (iPSC) using 4 human reprogramming factors (Oct4, Sox2, Klf4, and c-myc) under control of PiggyBac transposition vector. Fibroblasts derived from bovine fetuses were transfected using FugeneHD agent. After 21 days, colony-shaped structures on the culture plates were mechanically detached and then seeded on a mouse embryonic fibroblast (MEF) feeder layer pretreated with mitomycin C. The culture medium was DMEM/F12 supplemented with 20% serum replacement, 5 ng mL–1 basic fibroblast growth factor (bFGF), 0.1 mM β-mercaptoethanol, 1% NEAA, and 1% penicillin-streptomycin antibiotics. The iPSC colonies showed alkaline phosphatase activity and expressed several pluripotency markers (Oct4, Sox2, SSEA1, and SSEA4). To confirm differentiation potential, the iPSC were cultured as embryoid bodies and then plated again. βIII-tubulin (ectoderm) and GFAP or α-SMA (mesoderm) were well expressed on the attached cells. The results revealed that the bovine fibroblasts were well inducted to iPSC that had potential of multilineage differentiation. We hope this technology contributes to improving transgenic cattle production. This study was financially supported by IPET (grant # 109023-05-3-CG000, 111078-03-1-CG000) and the BK21 program for Veterinary Science.

52 IMPLANTATION OF TRANSGENIC BOVINE CLONED EMBRYOS DERIVED FROM TRANSFECTED CELLS BY PiggyBac TRANSPOSITION

A gene-delivery system, PiggyBac (PB) transposition, has been applied to transgene expression in mammalian cells or animals. In this study, to produce transgenic cattle, we used PB in bovine fibroblasts and then the transfected cells were microinjected into enucleated bovine oocytes to produce embryos and offspring. For this study, 2 different fluorescence genes (GFP, transcribed by constitutive promoter and RFP, transcribed by tetracycline-dependent promoter), which were flanked by PB sequences, were transfected into the bovine fetal fibroblasts by the FuGENE transfection protocol. The developmental rate of blastocysts among the cleaved embryos derived from GFP cells and doxycycline-induced RFP cells was developed at 23.1% (31/134) and 40.9% (442/1082), respectively. After transferring the GFP- or RFP-expressing blastocysts into recipient cows, pregnancies were detected by ultrasonography from both recipients of GFP or RFP. To know gene expression in fetal stage, embryonic sacs were collected surgically. The primary cells were successfully isolated from both embryonic sacs. Every cell from the GFP embryonic sac expressed GFP. When the cells from the RFP embryonic sac were treated with doxycycline, RFP was homogenously expressed. In conclusion, this study demonstrated that PB transposition could be applied to deliver genes into bovine somatic cells. Furthermore, transgenic embryos from transfected cells using the PB system were developed into blastocysts, implanted, and were able to form embryonic sacs. The PB system will be a useful method to produce transgenic cattle. This study was financially supported by IPET (grant no. 109023-05-3-CG000, 111078-03-1-CG000) and the BK21 Program for Veterinary Science.

158 EFFECTS OF AMINO ACIDS IN EMBRYO TRANSPORT MEDIA ON PORCINE EMBRYOS

Due to the distance from the laboratory to the recipient farm, several laboratories, including ours, carry somatic cell nuclear transfer (SCNT)-derived porcine embryos to the farm using a portable incubator for a few hours. If the embryos are nourished well during the transport, viability of embryos might be increased and cloning efficiency can be improved. TALP, which is widely used as a porcine embryo transport medium, lacks amino acids (AA). Proper supply of AA in the uterus is important for the development of pre-implantation embryos because AA have functions as osmolytes, metabolic regulators, or substrates and buffers of intracellular pH. Thus, supplementation of AA could affect the embryonic viability during the transport of SCNT-derived porcine embryos. The aim of this study is to determine whether the transport medium containing AAs affects the in vitro development of parthenogenetic embryos compared to TALP. Porcine zygote medium-5 (PZM-5) was chosen as transport medium containing AA due to its similarity in constituents with TALP except for the AA. Because PZM-5 contains sodium bicarbonate as a buffer system which can not cover wide variation of pH, 10 mM HEPES was added into PZM-5 (PZM+H) as it was normally done with TALP. Porcine cumulus–oocyte complexes (COC) were collected from ovaries of slaughtered pigs and cultured for 44 h using a two-step culture protocol. After denuded, matured oocytes were activated by thimerosal for 10 min followed by dithiothreitol for 30 min. The parthenogenetic embryos were cultured in PZM-5 for 2 days, monitored for cleavage, and loaded in a straw with TALP or PZM+H, respectively. Embryos were stored in a portable incubator (MTG, Bruckberg, Germany; no CO2) at 37°C for three hours and moved to PZM-5 drop for additional 5 days culture. The development was monitored on Day 7 after activation and blastocysts (BL) were collected for total cell number counts and RNA extraction. Ten BL from the TALP group and 11 BL from the PZM+H group were stained with 10 µg mL–1 bisbenzimide (Hoechst 33342) and were visualized for cell counting under fluorescence microscopy. Messenger RNA was extracted from 7 BL of the TALP and PZM+H groups and cDNA were synthesized. Quantitative real-time PCR were done to detect expression levels of apoptosis-related genes using the cDNA. The Bax/Bcl2 ratio was investigated as expression level of apoptosis-related genes and GAPDH was used as control. Each experiment was repeated at least 3 times. Data were analyzed by paired Student’s t-test using Graphpad Prism (version 5, Graphpad Software Inc., La Jolla, CA, USA). No difference was observed between the TALP and PZM+H groups with respect to blastocyst formation rate (22.46 ± 1.47% and 23.17 ± 2.13%, respectively) and total cell number (32.9 ± 2.22 and 37.09 ± 2.18, respectively). There was no significant difference between groups in the Bax/Bcl2 ratio. The use of PZM-5 media, which contains AA, did not affect the development and apoptosis of parthenogenetic embryos. This study was supported by MKE (#10033839-2012-21), IPET (#311011-05-1-SB010), the Research Institute for Veterinary Science, and TS Corporation.

Predictors of high score patient-reported barriers to controlling cancer pain: a preliminary report

PURPOSE

Pain is one of the most common and devastating symptoms in cancer patients, and misunderstandings on the patient's part can cause major obstacles in pain management.

METHOD

We evaluated factors associated with patient's high barrier score to managing cancer-associated pain by having 201 patients complete the Korean Barriers Questionnaire II, the Brief Pain Inventory--Korean, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and the Korean Beck Depression Inventory. The Pain Management Index (PMI) was also assessed.

RESULTS

The patients were from nine oncology clinics in university hospitals and a veterans' hospital in South Korea. The median pain score (0-10 scale) was 4, with a median percentage of pain improvement during the last 24 h of 70 %. A total of 150 patients (75 %) received strong opioids, and 177 (88 %) achieved adequate analgesia (positive PMI). Mean scores ± SD for the Barriers Questionnaire II ranged from 1.5 ± 1 to 2.8 ± 1.1, with the harmful effects subscale the highest. In the multiple regression model, depression was significantly associated with total barrier score to pain management (p < 0.0001). Pain reduction was significantly associated with the fatalism subscale.

CONCLUSIONS

Depression was associated with high barrier score in patients with cancer pain. Management of cancer pain should include screening for depression, and management of depression could reduce patient-reported barriers to pain management.

A phase II study of mitomycin-C and S-1 as third-line chemotherapy in patients with advanced colorectal cancer

This study was conducted to evaluate the efficacy and safety of the combination of mitomycin-C (MMC) and S-1 as third-line chemotherapy for patients with advanced colorectal cancer (CRC) showing resistance to irinotecan- and oxaliplatin-containing regimens. Patients were recruited into the study from January 2009 and 10 patients were enrolled for 10 months. However, since no patients had shown a response by 10 months, the study was terminated early according to the protocol. MMC 7 mg/m(2) was administered intravenously on day 1 every 6 weeks in the first 4 cycles. S-1 was administered twice daily at 35 mg/m(2), within 1 h of meals on days 1-14. Following a rest for 7 days, S-1 was administered again on days 22-35, followed by a 7-day rest. A total of 14 cycles were delivered for 10 patients. All 10 patients were assessable for response. A total of 3 patients (30%) had stable disease and the remaining 7 showed disease progression. With a median follow-up of 7 months, the median overall survival was 10.5 months. Grade 3-4 myelotoxicities included neutropenia in two patients, anemia in two and thrombocytopenia in one. Grade 1-2 nausea and vomiting developed in 5 patients. One patient experienced grade 3 diarrhea. Grade 1-2 hand-foot syndrome occurred in 4 patients. In conclusion, the combination of MMC and S-1 as third-line chemotherapy in patients with advanced CRC appears to be well tolerated but has poor activity.

Randomized phase II study of preoperative concurrent chemoradiotherapy with or without induction chemotherapy with S-1 and oxaliplatin in patients with resectable esophageal cancer

4093

Background: The value of adding induction chemotherapy (ICT) to preoperative chemoradiotherapy followed by surgery has not been delineated well. Methods: Patients with stage II, III or IVA (by AJCC 6th ed.) esophageal cancer were randomly allocated to either 2 cycles of ICT (oxaliplatin 130 mg/m2 on day 1 and S-1 at 40 mg/m2 bid on days 1-14, every 3 weeks), followed by concurrent chemoradiotherapy (CCRT) (46 Gy, 2 Gy/day with oxaliplatin 130 mg/m2 on day 1 and 21 and S-1 30 mg/m2 bid, 5 days/week during radiotherapy) and surgery (arm A, n=48), or the same chemoradiotherapy followed by surgery without ICT (arm B, n=49). Primary outcome was to compare pathologic complete response (pCR). Results: Thirty six and 35 patients underwent surgery with or without ICT, respectively. pCR rate among those who underwent surgery was significantly lower in arm A (30.6% vs. 54.3%, p=0.043). However, no difference in progression-free survival (PFS) and overall survival (OS) was observed with a median follow-up of 19.5 mo (95% CI, 19.1-22.4). Two-year PFS rate was 63.8% in arm A and 55.2% in arm B (p=0.626) and 2-year OS rate was 70.1% and 62.6%, respectively (p=0.515). While 47 (arm A) and 48 (arm B) patients received at least 44 Gy of radiotherapy, relative dose intensity (RDI) for oxaliplatin during CCRT was significantly lower in arm A vs. arm B (92.7% ± 19.6% vs. 99.7 ± 1.8%, p=0.017). RDI for S1 did not significantly differ (94.1% ± 17.3% vs. 98.5% ± 5.9%, p=0.095). G3/4 thrombocytopenia was significantly common in arm A (37.5% vs. 4.1%, p <0.001), which contributed to lower RDI of oxaliplatin. Three patients in arm A, compared to none in arm B, failed to survive for 90 days after surgery. Conclusions: Adding this ICT to preoperative chemoradiotherapy seems to cause lower pCR rate and higher toxicity during CCRT.

A phase I/II study of bortezomib plus CHOP every 2 weeks (CHOP-14) in patients with advanced-stage diffuse large B-cell lymphomas

Background

Bortezomib targets molecular dysregulation of nuclear factor-κB activation and cell cycle control, which are characteristic features of diffuse large B-cell lymphoma (DLBCL). We evaluated the safety and efficacy of bortezomib treatment with dose-dense cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) every 2 weeks (CHOP-14).

Methods

Untreated DLBCL patients were enrolled. A phase I dose-escalation study with 1.0, 1.3, and 1.6 mg/m² bortezomib administration on day 1 and 4 in addition to the CHOP-14 regimen was performed to determine the maximum tolerated dose (MTD) and the dose-limiting toxicity (DLT). Lenograstim 5 µg/kg/d was administered on day 4-13. The bortezomib dose from the phase I study was used in the phase II study.

Results

Nine and 37 patients were enrolled in the phase I and phase II studies, respectively. The analysis of the phase II results (40 patients) included data of the 3 patients in the last MTD dose cohort of the phase I trial. During the phase I trial, no DLT was observed at any bortezomib dose; therefore, the recommended dose was 1.6 mg/m². In phase II, the overall response rate was 95% (complete response: 80%; partial response: 15%). Nine out of the 40 patients showed grade 3 sensory neuropathy, and 22 required at least 1 dose reduction. Three patients could not complete the intended 6 cycles of treatment because of severe neuropathy.

Conclusion

Bortezomib plus CHOP-14 was highly effective for the treatment of untreated DLBCL patients, but in many cases, dose or schedule modification was required to reduce neurotoxicity.

64 USING PORCINE GRANULOSA CELLS AS FEEDERS FOR PORCINE AND BOVINE TROPHECTODERM CELL CULTURE

The trophectoderm cells, arising from the outer side of the blastomere in the blastocyst stage, are the first differentiated embryonic cells with specific potential as stem cells. The physiology of trophectoderm cells has been studied; however, their functions still remain unclear, because the lack of definitive information of cell lineages. Here, we aimed to establish in culture different feeder-dependent trophectoderm cell lines from 9-day, preimplantation, in vitro-produced porcine and bovine embryos. We used 2 different feeders: porcine granulosa cells (PGC) and mouse embryonic fibroblasts (MEF). Both cells were mitotically inactivated by mitomycin-C and then cultured with a density of 5 × 104 mL–1 on 0.1% (wt/vol) gelatin coated 4-well dishes in DMEM-199 medium supplemented with 10% (vol/vol) fetal bovine serum (FBS), nonessential amino acids (NEAA), β-mercaptoethanol and nucleosides (Talbot et al. 2000 Biol. Reprod. 62, 235–247). Trophectoderm cells were observed by light microscopy and characterised by reverse transcription-PCR using specific primers for both species. Different feeders and trophectoderm cells growth rates were compared after trypsinization using a hemocytometer. Data were analysed using 1-way ANOVA. In results, trophectoderm cells display epithelial characteristics, cuboidal morphology and express mRNA of homebox protein CDX2, cytokeratin 8 (KRT8) and interferon (IFN) gamma or tau for porcine or bovine cells, respectively. Moreover, oestrogen receptor (ESR1) and progesterone receptor (PGR) were expressed in trophectoderm cells of both species. Porcine granulosa cells were highly proliferative with doubling time of 24 h when compared to MEF (P ≤ 0.5), easy to recover and provided a reasonable source of steroids, 17β-oestradiol (E2; 31.21 ± 3.1 ng mL–1) and progesterone (P4; 6.36 ± 0.4 ng mL–1). Moreover, trophectoderm cell colonies of both species that cultured on PGC grew faster, with a doubling time of 48 h when compared to those cultured on MEF (P ≤ 0.5). We speculate that the continuous supplement of steroids and other cytokines during the co-culture of trophoblasts with granulosa cells might help the trophectoderm cells growth more than that of MEF. Further investigations are required in this regard. In conclusion, porcine granulosa cells can be good alternative feeders to culture porcine and bovine trophectoderm. This research was supported by MKE (Grant # 10033839-2011-13) and IPET.

32 NEURON-SPECIFIC EXPRESSION OF THE RED FLUORESCENCE PROTEIN IN CLONED DOGS

The pathogenesis of neuronal degenerative disease as Alzheimer's disease (AD) has been a subject of intensive research for the last few decades worldwide. But despite such effort, treatment or preventive measures for AD have so far made no breakthrough. One of the contributing factors that hindered the progress of research is the lack of appropriate AD models. Mouse models have limitations for AD research because the irreconcilable species gap between the rodent and human has impeded the research itself as well as the application of the findings from the rodent studies to human cases. As an alternative, here we performed a preliminary study to develop novel neuronal degenerative disease models using a canine transgenic somatic cell nuclear transfer (SCNT) technology. The aim of this study is to produce a transgenic dog that expresses neuron-specific transgene in the brain by SCNT. In this study, we chose human synapsin 1 promoter as primarily neuron selective, driving the red fluorescent protein transgene. For SCNT, synapsin 1-red fluorescence protein (SYN1-RFP) was introduced into female beagle adipose-derived stem cell via lentiviral vector infection. The SYN1-RFP cells were injected into enucleated in vivo-matured dog oocytes and fused by electric stimulation. The fused couplets (80/94, 85.1%) were chemically activated and transferred into the uterine tube of 5 naturally oestrus-synchronized surrogates. Three of them (60%) maintained pregnancy and subsequently gave birth to 3 cloned pups (SYN1-RFP A, SYN1-RFP B, SYN1-RFP C) by natural delivery or cesarean section. Birth weights of the offspring ranged from 120 to 280 g and SYN1-RFP C is still alive, healthy and does not show any abnormalities. The microsatellite analysis shows that all SYN1-RFP puppies originated from the SYN1-RFP cells used in SCNT and mitochondrial DNA analysis shows that the puppies had been derived from the oocyte donors. In order to investigate the result in multiple transgene insertions, SYN-RFP puppies were screened by Southern blot analysis using DNA extracted from skin biopsies. Transgene copy number was estimated by Southern blot analysis. The SYN-RFP A and B that died at 3 days after birth had approximately 5 and 2 copies of the transgene integrated, respectively, whereas the alive SYN-RFP C has 1 copy. SYN-RFP B was particular in that it did not express RFP in the entire body, but samples collected postmortem showed expression of the RFP transgene under the human synapsin 1 promoter in neural cells in the brain of SYN-RFP B. In conclusion, we report here that (1) the human synapsin promoter is functional in neural cells of dog brain and (2) a neural-specific-transgene-expressed dog was generated for the first time by transgenic SCNT technique. Furthermore, the SYN-RFP dog has great potential to understand the function of a neuronal degenerative disease model dog. This study was supported by MKE (Grant # 10033839-2011-13), RNL Bio, IPET and TS Corporation.

33 IN VITRO IMMUNOGENICITY OF SOMATIC CELL NUCLEAR TRANSFER-DERIVED TRANSGENIC CLONED DOGS

Histocompatible tissue has been generated by somatic cell nuclear transfer (SCNT) and the resultant tissues were not rejected by the immune system of the nucleus donors. In addition, many transgenic animals combined with SCNT have been produced. However, in vitro immunogenicity of transgenic cloned animals originated from the same donor cell with nontransgenic cloned animals has not been assessed until now. The objective of this study was to evaluate the in vitro immunogenicity of cloned dogs with each other, between cloned dogs and transgenic cloned dogs and between transgenic cloned dogs with each other by mixed lymphocyte reaction. In this study, we used cloned beagles (BG1, 2) derived from SCNT using fetal fibroblasts (BF3). Serially, 4 transgenic cloned beagles (Ruppy 1–3, 5) were also genetically engineered from the same donor cell, BF3, with red fluorescent protein (RFP) gene inserted into their genome. We used 2 age-matched healthy female beagle dogs as control dogs. They have different 3 DLA types with all cloned dogs. Peripheral blood mononuclear cells (PBMC) of 2 cloned beagles and 4 transgenic cloned beagles were isolated from whole bloods using Ficoll gradient solution. PBMC from each dog were mixed to auto PBMC, other transgenic cloned dogs and non-related control dogs under the experimental designs. All the mixtures were incubated at 37°C for 4 days, adding BrdU labeling reagent and re-incubated for 24 h. Results are expressed in absorbance mean value ± standard deviation of 450-nm wavelength read by microplate reader. Each cell combination was assayed in 8 replicates. In Experiment 1, PBMC of cloned beagles were combined with equal concentrations of another cloned beagle's PBMC. In Experiment 2, PBMC suspension of Ruppy 1–3, 5 were mixed with equal concentrations of another transgenic cloned beagle's PBMC suspension. In Experiment 3, PBMC suspensions of cloned beagles were mixed with PBMC suspensions of transgenic cloned beagles and reverse reaction was performed. Statistical analysis was performed by using Mann-Whitney U test. In Experiment 1, whereas the absorbance value of mixture of cloned dogs and control dogs shows apparent proliferation, auto mixture of each dog and allo-mixture of BG1 and BG2 show no proliferation (Table 1), indicating immunological factors exposed to PBMC in 2 cloned dogs were compatible. In Experiment 2 among transgenic cloned dogs, no evidence of proliferations in mixed allo-PBMC was shown (Table 1), suggesting in vitro immunogenicity between transgenic cloned dogs was also not shown. In Experiment 3 among cloned dogs and transgenic cloned dogs, no significant difference was found (Table 1). In conclusion, cloned dogs derived from SCNT shared immunological phenotype. Next, immunogenicity among transgenic cloned beagle dogs was not shown despite random insertion of a foreign gene. Lastly, cloned beagles and transgenic cloned beagles show lymphocyte antigen compatibility irrespective of having a foreign gene or not. Table 1.The absorbance values of mixed lymphocytes of 4 transgenic cloned dogs and 2 cloned dogs This study was supported by RNL BIO (#0468-20110001), IPET, MKE (#10033839-2011-13) and Natural Balance Korea.

Addition of rituximab to the CHOP regimen has no benefit in patients with primary extranodal diffuse large B-cell lymphoma

BACKGROUND

The addition of rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy (R-CHOP) has significantly improved clinical outcomes for patients with diffuse large B-cell lymphoma (DLBCL). However, new predictors of patient response to R-CHOP have not been established. We aimed to evaluate the impact of R-CHOP compared with CHOP in patients with DLBCL and to establish clinical predictors of better outcomes in these patients.

METHODS

We retrospectively identified 177 patients diagnosed with CD20-positive DLBCL and treated with CHOP (N=82) or R-CHOP (N=95). The response rate, event-free survival (EFS), and overall survival (OS) rates were compared between the 2 treatment groups. All patients were classified into primary extranodal lymphoma (PENL) or nodal lymphoma (NL) subgroups, and the clinical parameters of each subgroup were analyzed.

RESULTS

The overall response rate was higher in R-CHOP group (95% vs. 84%, P=0.07). The 3-year EFS rate was significantly higher in R-CHOP group (71% vs. 52%, P=0.013), but the OS rate was comparable between the 2 groups (79% vs. 69%, P=0.23). A significant survival benefit was seen with R-CHOP compared to CHOP therapy in NL patients (P=0.002 for EFS and 0.04 for OS). Multivariate analyses confirmed that R-CHOP therapy is an independent prognostic factor for EFS (hazard ratio of 0.32 [0.17-0.62], P=0.001) and OS (hazard ratio of 0.4 [0.18-0.87], P=0.02) in NL patients.

CONCLUSION

Patients in the PENL group did not benefit from R-CHOP chemotherapy.

Effect of roscovitine-treated donor cells on development of porcine cloned embryos

Synchronization of the donor cell cycle is an important factor for successful animal cloning by nuclear transfer. To improve the efficiency of porcine cloning, in the present report, we evaluated effects of contact inhibition, serum starvation and roscovitine treatment of donor cells on in vitro and in vivo developmental potency of cloned porcine embryos. Fibroblasts derived from a porcine foetus at day 30 of gestation were isolated and cultured to 70% confluency. Then, cells were either cultured to 100% confluency for contact inhibition, or cultured in 0.5% serum for 72 h for serum starvation or with 15 μM roscovitine for 24 h. Cells were most effectively synchronized at G0/G1 in the serum starvation group (87.5%) compared with the contact inhibition and roscovitine treatment groups (76.3% and 79.9% respectively p < 0.05). However, after somatic cell nuclear transfer followed by in vitro culture, the serum starvation group showed a significantly lower blastocyst formation rate (5.6%) compared with the contact inhibition and roscovitine treatment groups (11.6% and 20.0% respectively). Differential expression of apoptosis-related genes and the level of apoptosis in each treatment group explain the variation in developmental competence among the groups. Significantly higher level of apoptosis was observed in the serum starvation group. On the other hand, the roscovitine treatment group shows the lowest level of apoptosis and the best in vitro development among the groups. Cloned embryos derived from roscovitine-treated donor cells were transferred to surrogate pigs. Three healthy live piglets were produced. In conclusion, we suggest that roscovitine treatment of donor cells improves development of cloned porcine embryos and can raise the efficiency of cloned piglet production.