• 대한임상검사과학회지
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• 제43권3호
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• pp.89-97
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• 2011

The Human Papilloma Virus (HPV) infection has been strongly associated with pathogenesis of uterine cervix carcinoma. HPV type 16, a causative agent of uterine cervix carcinoma, encodes the E6 and E7 oncogenes, expression of which is pivotal for malignant transformation and maintenance of malignant phenotypes. To develop a gene therapy for HPV-related carcinoma, We investigated the effect of E6 short-interfering RNA (E6 siRNA) on the expression of this oncogene and on the growth of HPV 16-related uterine cervix carcinoma cells. SiHa cells, a uterine cervix carcinoma cell line, which contain a single copy of HPV 16 integrated in the chromosome and express the E6 and E7 oncogenes. Before 24 hr of transfection, cells were seeded and transfected with control plasmid or E6 siRNA-expressing plasmid. The mRNA was analysed by reverse transcriptase polymerase chain reaction (RT-PCR). The cell growth rate was investigated by MTT method. The E6 mRNA level in SiHa cells was decreased in HPV 16 E6 siRNA-expression vector transfected cells and a decrease in the growth of these cells was also observed. From these results. it is evident that E6 siRNA played a role in suppression of growth of SiHa cells and has a fair chance as a candidate for gene specific therapy for HPV related uterine cervix carcinoma.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.26-26
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• 2015

Phytophthora infestans is the causal agent of potato and tomato late blight, one of the most devastating plant diseases. P. infestans secretes effector proteins that are both modulators and targets of host plant immunity. Among these are the so-called RXLR effectors that function inside plant cells and are characterized by a conserved motif following the N-terminal signal peptide. In contrast, the effector activity is encoded by the C terminal region that follows the RXLR domain. Recently, I performed in planta functional profiling of different RXLR effector alleles. These genes were amplified from a variety of P. infestans isolates and cloned into a Potato virus X (PVX) vector for transient in planta expression. I assayed for R-gene specific induction of hypersensitive cell death. The findings included the discovery of new effector with avirulence activity towards the Solanum bulbocastanum Rpi-blb2 resistance gene. The Rpi-blb2 encodes a protein with a putative CC-NBS-LRR (a coiled-coil-nucleotide binding site and leucine-rich repeat) motif that confers Phytophthora late blight disease resistance. We examined the components required for Rpi-blb2-mediated resistance to P. infestans in Nicotiana benthamiana. Virus-induced gene silencing was used to repress candidate genes in N. benthamiana and to assay against P. infestans infections. NbSGT1 was required for disease resistance to P. infestans and hypersensitive responses (HRs) triggered by co-expression of AVRblb2 and Rpi-blb2 in N. benthamiana. RAR1 and HSP90 did not affect disease resistance or HRs in Rpi-blb2-transgenic plants. To elucidate the role of salicylic acid (SA) in Rpi-blb2-mediated resistance, we analyzed the response of NahG-transgenic plants following P. infestans infection. The increased susceptibility of Rpi-blb2-transgenic plants in the NahG background correlated with reduced SA and SA glucoside levels. Furthermore, Rpi-blb2-mediated HR cell death was associated with $H_2O_2$, but not SA, accumulation. SA affects basal defense and Rpi-blb2-mediated resistance against P. infestans. These findings provide evidence about the roles of SGT1 and SA signaling in Rpi-blb2-mediated resistance against P. infestans.

• Biomolecules & Therapeutics
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• 제26권6호
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• pp.591-598
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• 2018

Epigenetic silencing is considered to be a major mechanism for loss of activity in tumor suppressors. Reversal of epigenetic silencing by using inhibitors of DNA methyltransferase (DNMT) or histone deacetylases (HDACs) such as 5-Aza-CdR and FK228 has shown to enhance cytotoxic activities of several anticancer agents. This study aims to assess the combinatorial effects of genesilencing reversal agents (5-Aza-CdR and FK228) and oxaliplatin in gastric cancer cells, i.e., Epstein-Barr virus (EBV)-negative SNU-638 and EBV-positive SNU-719 cells. The doublet combinatorial treatment of 5-Aza-CdR and FK228 exhibited synergistic effects in both cell lines, and this was further corroborated by Zta expression induction in SNU-719 cells. Three drug combinations as 5-Aza-CdR/FK228 followed by oxaliplatin, however, resulted in antagonistic effects in both cell lines. Simultaneous treatment with FK228 and oxaliplatin induced synergistic and additive effects in SNU-638 and SNU-719 cells, respectively. Three drug combinations as 5-Aza-CdR prior to FK228/oxaliplatin, however, again resulted in antagonistic effects in both cell lines. This work demonstrated that efficacy of doublet synergistic combination using DNMT or HDACs inhibitors can be compromised by adding the third drug in pre- or post-treatment approach in gastric cancer cells. This implies that the development of clinical trial protocols for triplet combinations using gene-silencing reversal agents should be carefully evaluated in light of their potential antagonistic effects.

• The Plant Pathology Journal
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• 제40권1호
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• pp.59-72
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• 2024

A comprehensive survey of mungbean-growing areas was conducted to observe leaf spot disease caused by Alternaria alternata. Alternaria leaf spot symptoms were observed on the leaves. Diversity of 50 genotypes of mungbean was assessed against A. alternata and data on pathological traits was subjected to cluster analysis. The results showed that genotypes of mungbean were grouped into four clusters based on resistance parameters under the influence of disease. The principal component biplot demonstrated that all the disease-related parameters (% disease incidence, % disease intensity, lesion area, and % of infection) were strongly correlated with each other. Alt a 1 gene that is precisely found in Alternaria species and is responsible for virulence and pathogenicity. Alt a 1 gene was amplified using gene specific primers. The isolated pathogen produced similar symptoms when inoculated on mungbean and tobacco. The sequence analysis of the internal transcribed spacer (ITS) region, a 600 bp fragment amplified using specific primers, ITS1 and ITS2 showed 100% identity with A. alternata. Potato virus X (PVX) -based silencing vector expressing Alt a 1 gene was constructed to control this pathogen through RNA interference in tobacco. Out of 50 inoculated plants, 9 showed delayed onset of disease. Furthermore, to confirm our findings at molecular level semi-quantitative reverse transcriptase polymerase chain reaction was used. Both phenotypic and molecular investigation indicated that RNAi induced through the VIGS vector was efficacious in resisting the pathogen in the model host, Tobacco (Nicotiana tabacum). To the best of our knowledge, this study has been reported for the first time.

• The Plant Pathology Journal
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• 제30권3호
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• pp.254-260
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• 2014

Potato Rpi-blb2 encodes a protein with a coiled-coil-nucleotide binding site and leucine-rich repeat (CC-NBSLRR) motif that recognizes the Phytophthora infestans AVRblb2 effector and triggers hypersensitive cell death (HCD). To better understand the components required for Rpi-blb2-mediated HCD in plants, we used virus-induced gene silencing to repress candidate genes in Rpi-blb2-transgenic Nicotiana benthamiana plants and assayed the plants for AVRblb2 effector. Rpi-blb2 triggers HCD through NbSGT1-mediated pathways, but not NbEDS1- or NbNDR1-mediated pathways. In addition, the role of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) in Rpi-blb2-mediated HCD were analyzed by monitoring of the responses of NbICS1-, NbCOI1-, or NbEIN2-silenced or Rpi-blb2::NahG-transgenic plants. Rpi-blb2-mediated HCD in response to AVRblb2 was not associated with SA accumulation. Thus, SA affects Rpi-blb2-mediated resistance against P. infestans, but not Rpi-blb2-mediated HCD in response to AVRblb2. Additionally, JA and ET signaling were not required for Rpi-blb2-mediated HCD in N. benthamiana. Taken together, these findings suggest that NbSGT1 is a unique positive regulator of Rpi-blb2-mediated HCD in response to AVRblb2, but EDS1, NDR1, SA, JA, and ET are not required.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1037-1047
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• 2016

HOX transcription factors are evolutionarily conserved in many different species and are involved in important cellular processes such as morphogenesis, differentiation, and proliferation. They have also recently been implicated in carcinogenesis, but their precise role in cancer, especially in cervical cancer (CC), remains unclear. In this work, using microarray assays followed by the quantitative polymerase chain reaction (qPCR), we found that the expression of 25 HOX genes was downregulated in CC derived cell lines compared with non-tumorigenic keratinocytes. In particular, the expression of HOXA9 was observed as down-modulated in CC-derived cell lines. The expression of HOXA9 has not been previously reported in CC, or in normal keratinocytes of the cervix. We found that normal CC from women without cervical lesions express HOXA9; in contrast, CC cell lines and samples of biopsies from women with CC showed significantly diminished HOXA9 expression. Furthermore, we found that methylation at the first exon of HOXA9 could play an important role in modulating the expression of this gene. Exogenous restoration of HOXA9 expression in CC cell lines decreased cell proliferation and migration, and induced an epithelial-like phenotype. Interestingly, the silencing of human papilloma virus (HPV) E6 and E7 oncogenes induced expression of HOXA9. In conclusion, controlling HOXA9 expression appears to be a necessary step during CC development. Further studies are needed to delineate the role of HOXA9 during malignant progression and to afford more insights into the relationship between downmodulation of HOXA9 and viral HPV oncoprotein expression during cercical cancer development.

• Journal of Plant Biotechnology
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• 제43권3호
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• pp.261-271
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• 2016

세계적인 과수작물로서의 경제적 중요성에도 불구하고, 감귤 생산은 주로 자연교잡 실생이나 눈 돌연변이로부터의 선발 또는 단순 품종 도입 등을 통해 이루어지고 있는 실정이다. 긴 유년기, 다배성, 자가불화합성과 같은 감귤 고유의 식물학적 특성, 주요 형질들(병저항성, 수량성, 품질 등)의 QTL에 의한 조절 등은 전통 육종을 통한 우수 품종의 개발을 어렵게 하는 요인이다. 지구 온난화에 의한 생산 여건의 급격한 변화, 소비자 요구 다양화 등은 고품질 감귤의 조기 선발과 안정적 생산, 품종 다양화, 육종 비용 절감 등을 위한 체계적인 감귤 분자육종 프로그램의 도입을 요구하고 있다. 동위효소를 이용한 최초의 감귤 연관지도 작성이 이루어진 이래, 다양한 분자표지를 이용한 연관지도 작성, 생물(CTV, CiLV, ABS, 선충] 및 비생물적(염분, 저온) 스트레스, 아포믹시스, 다배성, 과실착색(카로티노이드, 안토시아닌), 무종자, 웅성불임, 신맛 적음, 생식, 형태(나무, 잎, 꽃, 열매 등), 과실 품질, 종자수, 수량성, 조기 착과 등과 연관된 분자표지 발굴, QTL 맵핑 등이 이루어졌다. CTV 저항성과 적육(안토시아닌 축적) 형질에 대해서는 유전자 클로닝이 이루어졌고, 교배 육종 효율 증대 및 비용 절감을 위해 교잡배와 주심배를 구분하기 위한 다수의 simple sequence repeat (SSR) 분자표지가 개발되었다. 최근, 스위트오렌지와 '클레멘타인' 만다린에 대한 고품질의 표준 유전체가 완성되어 유전체 기반 감귤 분자육종을 위한 토대가 마련되었다. 표준 유전체 정보를 토대로 대규모 분자표지(SNP, SSR, InDel) 기반의 표준 연관 및 물리지도 작성, 비교 유전체 지도 작성, gene annotation, 전사체 분석 등이 활발히 이루어지고 있다. 감귤 유전자원 및 핵심집단에 대해 표준 유전체 기반 비교 유전체 분석, GBS (genotyping-by-sequencing), GWAS (genome wide association study) 등을 통해 감귤의 다양한 형질과 연관된 분자마커 발굴 및 개발, 유용/변이 유전자 클로닝 등에 관한 연구가 가속화될 것으로 전망된다. 또한 표적 유전체 교정 및 VIGS (virus-induced gene silencing) 기술도 유전자 마커의 검증을 비롯한 감귤 분자육종 프로그램에 활발히 이용될 것이다.