Kyung-Tai Kim

Adenovirus-mediated Suicide Gene Therapy Using the Human Telomerase Catalytic Subunit (hTERT) Gene Promoter Induced Apoptosis of Ovarian Cancer Cell Line

Telomerase is a ribonucleoprotein complex the function of which is to add telomeric repeats (TTAGGG)n to chromosomal ends, and it is known to play an important role in cellular immortalization. Telomerase is highly active in most tumor cells, yet not in normal cells. As such, it may have possible applications in cancer gene therapy. Telomerase consists of two essential components, telomerase RNA template (hTR) and catalytic subunit (hTERT). hTERT is expressed only in cells and tissues positive for telomerase activity, i.e., tumor and fetal cells. We here tested the possibility of the utilization of the hTERT promoter in targeted cancer gene therapy. We cloned the hTERT promoter in the replace of the CMV promoter and sub-cloned HSV-TK gene to be controlled by hTERT gene promoter in adenovirus shuttle plasmid. Then we constructed recombinant adenovirus Ad-hT-TK, and infected them into normal and human gynecological cancer cell lines. Through these experiments, we identified the selective tumor specific cell death by Ad-hT-TK. Furthermore, FACS analysis and TUNEL assay suggests that the reduced viability is mediated through the induction of apoptosis, indicating that this approach may be a useful method for suppressing cancer growth in targeted cancer gene therapy. These results show that Ad-hT-TK could be used for gynecological cancer gene therapy.

AB0107 Association Heterogeneity Mapping Identifies An Asian-Specific Association of The GTF2I Locus with Rheumatoid Arthritis

Background Genetic association studies using multiple ancestral cohorts have revealed a large overlap of rheumatoid arthritis (RA)-risk alleles among different ancestries, but there are some exceptional loci showing heterogenic association among populations. Objectives Here we investigated genetic variants with distinct effects on the development of RA in Asian and European populations. Methods Ancestry-related association heterogeneity was examined using the association data from large Korean (n=9,299) and European (n=45,790) rheumatoid arthritis cohorts with Immunochip and genome-wide SNP array data. Novel disease associations detected in Koreans were validated using two independent Asian cohorts (n=5,166) and a meta-analysis. Results We identified significant heterogeneity between the two ancestries for the common variants in the GTF2I locus and showed that this heterogeneity is due to an Asian-specific association effect (PHeterogeneity =9.6×10-9 at rs73366469 [ORMeta =1.37 and PMeta =4.2×10–13 in Asians; ORMeta =1.00 and PMeta =1.00 in Europeans]) in RA. Trans-ancestral comparison and bioinfomatics analysis revealed a plausibly causal SNP (rs117026326; linked to rs73366469), whose minor allele is common in Asians but rare in Europeans. Conclusions We identified the largest effect on Asian RA across human non-HLA regions at GTF2I by heterogeneity mapping followed by replication studies, and pinpointed a possible causal variant. References Okada, Y. et al. Genetics of rheumatoid arthritis contributes to biology and drug discovery. Nature 506, 376–81 (2014). Kim, K. et al. High-density genotyping of immune loci in Koreans and Europeans identifies eight new rheumatoid arthritis risk loci. Ann Rheum Dis 74, e13 (2015). Acknowledgement This study was supported by the Korea Healthcare Technology R&D Project of the Ministry for Health & Welfare (HI13C2124), the Japanese Ministry of Education, Culture, Sports, Science and Technology Grant-in-Aid for Scientific Research (15H04965) and the US National Institutes of Health (R01MD007909 and R01AR060366). *Drs. Kwangwoo Kim and So-Young Bang contributed equally to this work. Disclosure of Interest None declared

THU0003 Searching for the Genetic Variants Associated with Bone Erosion of Rheumatoid Arthritis Using High-Density Genotype Data for Immune Loci in a Korean Population

Background Radiographic joint damage is highly variable among rheumatoid arthritis patients. Since the heritability of joint destruction rate was estimated to 45-58% in previous twin and the Icelandic RA-population studies, it is highly suggested that genetic variants are involved in the process of joint destruction and cause the different amount of joint damage among the patients. Objectives We aimed to examine genetic variants and biological pathways associated with bone erosion using high-density genotype data for immune loci in Koreans. Methods We analyzed ∼100,000 immune-loci SNPs for their associations with bone erosion in 1,142 RA patients. The subjects were genotyped by Immunochip, a high-density genotyping array for immune disease loci (n=343), or imputed for the Immunochip SNPs from our previous genomoe-wide association study (GWAS) array by SHAPEIT and IMPUTE2 (n=799). The patients were classified into two groups based on the Steinbrocker staging system: non-erosive (stages I and II) and erosive (stages III and IV) RA. The association between SNPs and bone erosion was tested for the genotyping and imputation-based data separately, by multivariate logistic regression with adjustment of age, sex, disease duration, and smoking status at symptom onset using PLINK. The association results from both datasets were combined in a fixed-effect meta-analysis by using GWAMA. Enrichment of associated variants in the known biological pathways and gene-sets was further tested from the meta-analysis results by MAGENTA. Results By testing the associations between the 99,177 SNPs and bone erosion in 446 erosive and 387 non-erosive RA patients, rs10782763 (OR=1.64, P=2.95×10-5) and rs12095896 (OR =1.60, P=5.28×10-5) near LPHN2 and rs10263303 (OR=1.81, P=8.41×10-5) near PTPRN2 (or DNAJB6) were potential SNPs associated with bone erosion in RA, but none reached the genome-wide significance threshold. In the gene-set enrichment analysis, five candidate causal pathways were identified: the ataxia telangiectasia-mutated gene (ATM), vascular endothelial growth factor (VEGF), C-C chemokine receptor type 5 (CCR5), Src by protein-tyrosine phosphatase alpha (srcRPTP), and free radical induced apoptosis (FREE) pathways (P<0.05, BioCarta database).Table 1. Polymorphism possibly associated with bone erosion in patients with RA Meta-analysis iCHIP data Imputed iCHIP data SNP CR Gene name Ref. allele Risk allele OR P value OR P value OR P value rs10782763 1 LPHN2 C A 1.68 2.95x10-5 1.80 1.63x10-2 1.64 5.85x10-4 Rs12095896 1 LPHN2 C A 1.64 5.28x10-5 1.76 2.05x10-2 1.60 8.59x10-4 Rs10263303 7 DNAJB6, PTPRN2 G A 1.80 8.41x10-5 1.77 8.04x10-2 1.81 4.19x10-4 Conclusions We could not find any immune-loci SNPs surpassing genome-wide significance level in our study subjects, although we identified suggestive associations at several SNPs, raising the possibilities that genetic variants for joint erosion would locate beyond the immune loci, unlike RA susceptibility genes and there is highly heterogenous genetic etiology in joint erosion. In addition, we identified five biological pathways associated with bone erosion, which might provide insight into the molecular mechanisms underlying the radiographic damage in RA. Disclosure of Interest None declared

A novel EGR system to improve engine performance of a diesel engine

A recent focus on automotive researches is to reduce CO2 emission due to stringent regulation. Auto makers has been dealing such regulations with either applying novel combustion strategies or utilizing alternative fuels for IC engines. In addition, low emission vehicles such as HEV and FCEV have developed to reduce emission and fuel consumption. Of IC engines, diesel engine having a higher thermal efficiency compared to gasoline engine has an advantage of a low CO2 emission. In this study, various effects of cooled EGR on diesel engine performances, emission and combustion characteristics were investigated. A separate cooling circuit in combination with additional heat exchangers were installed to control temperatures of EGR gas and charged air independently. As the EGR gas temperature was decreased, PM and NOx emission and BSFC were substantially reduced. However, the cooled EGR was found to increase THC and CO emissions.

Comparison between L and E gene amplification analytical methods for human papillomavirus typing

OBJECTIVE L and E6/E7 gene amplification analyses were compared to identify human papillomavirus (HPV) infection and verify the HPV type, with the intent to minimize HPV typing errors. METHODS L1 gene verified HPV typing was accomplished via polymerase chain reaction (PCR) and membrane assays. Verification of HPV typing via E6/E7 genes was accomplished through nested multiplexed PCR. The results from 104 samples were compared. RESULTS The rates of accordance and difference were 35% and 65%, respectively. For 29% of the analyses, nested multiplexed PCR was more diversified than the membrane assay. CONCLUSION HPV can be classified into low-risk HPV and high-risk HPV groups. In parallel amplifications of the L and E genes is more efficient for accurate diagnosis in light of the different symptoms and attendant precautions of the risk groups.