• Title/Summary/Keyword: DNA.

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Polymorphisms of GSTM1 and CYP1A1, and Susceptibility to Primary Lung Cancer in Korean Males (한국인 남성에서 GSTM1과 CYP1A1 유전자 다형성과 원발성폐암의 유전적 감수성)

  • Bae, Nack-Cheon;Lee, Su-Yeon;Chae, Po-Hee;Kang, Kyung-Hee;Kim, Kyung-Rock;Cha, Seung-Ick;Chae, Sang-Chul;Kim, Chang-Ho;Jung, Tae-Hoon;Park, Jae-Yong
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.5
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    • pp.568-578
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    • 2001
  • Background : Lung cancer is frequently cited as an example of a disease caused solely by exposure to environmental carcinogens. However, there is a growing realization that the genetic constitution is also important in determining individual's susceptibility to lung cancer. This genetic susceptibility may result from functional polymorphims of the genes involved in carcinogen metabolism. In this study, the association between GSTM1 and CYP1A1 polymorphisms and the lung cancer risk in Korean males was investigated. Materials and Method : The study population consisted of 153 male lung cancer patients and 143 healthy male controls. The GSTM1 and CYP1A1 genotypes were determined by multiplex PCR and PCR-RFLP analysis. Result : There were no significant differences in the frequency of the GSTM1 null genotype between the cases and the controls. When the cases were categorized by their histologic type, the frequency of the GSTM1 null genotype in the small cell carcinoma group was higher than those of the controls(67.2% vs 55.9%), but the difference was not statistically significant(OR=1.772 ; 95% CI=0.723-4.340). The distribution of the CYP1A1 MspI genotypes among the cases were similar to those among the controls. When the cases were grouped by their histologic type, the ml/m1, ml/m2, m2/m2 genotypes frequencies among the small cell carcinomas(23.0%, 38.5%, and 38.5%, respectively) were significantly different from those of the controls(36.4%, 46.2%, and 7.4%, respectively, p<0.05). When the m1/m1 genotype was used as a reference, the ml/m2 and m2/m2 genotypes were associated with an increased risk for small cell lung cancer(ml/m2 genotype : OR=1.337, 95% CI=0.453-3.947 ; m2/m2 genotype : OR=3.374, 95% CI=1.092-10.421). Conclusion : These results suggest that the GSTM1 and CYP1A1 genotypes may be a genetic determinant of the risk for lung cancer, particlulary small cell carcinoma. Further investigation is needed to confirm these results.

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Assessment of the Specificity of A Hybridization of Surfactant Protein A by Addition of Non-specific Rat Spleen RNA (Surfactant Protein A mRNA을 이용한 유전자 재결합 반응에서 비특이성 RNA의 첨가에 의한 특이성 검정)

  • Kim, Byeong Cheol;Kim, Mi Ok;Kim, Tae-Hyung;Sohn, Jang Won;Yoon, Ho Joo;Shin, Dong Ho;Park, Sung Soo
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.4
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    • pp.393-404
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    • 2004
  • Background : Nucleic acid hybridization has become an essential technique in the development of our understanding of gene structure and function. The quantitative analysis of hybridization has been used in the measurement of genome complexity and gene copy number. The filter hybridization assay is rapid, sensitive and can be used to measure RNAs complementary to any cloned DNA sequence. Methods : The authors assessed the accuracy, linearity, correlation coefficient and specificity of the hybridization depending on the added dose(0, 1, 5, and $10{\mu}g$) of non-specific rat spleen RNA to hybridization of surfactant protein A mRNA. Filter hybridization assays were used to obtain the equation of standard curve and thereby to quantitate the mRNA quantitation. Results : 1. Standard curve equation of filter hybridization assay between counts per minute (X) and spleen RNA input (Y) was Y=0.13X-19.35. Correlation coefficient was 0.98. 2. Standard curve equation of filter hybridization assay between counts per minute (X) and surfactant protein A mRNA transcript input (Y) was Y=0.00066X-0.046. Correlation coefficient was 0.99. 3. Standard curve equation of filter hybridization assay between counts per minute (X) and surfactant protein A mRNA transcript input (Y) after the addition of $1{\mu}g$ spleen RNA was Y=0.00056X-0.051. Correlation coefficient was 0.99. 4. Standard curve equation of filter hybridization assay between counts per minute (X) and surfactant protein A mRNA transcript input (Y) after the addition of $5{\mu}g$ spleen RNA was Y=0.00065X-0.088. Correlation coefficient was 0.99. 5. Standard curve equation of filter hybridization assay between counts per minute (X) and surfactant protein A mRNA transcript input (Y) after the addition of $10{\mu}g$ spleen RNA was Y=0.00051X-0.10. Correlation coefficient was 0.99. Conclusions : Comparison of cpm/filter in a linear range allowed accurate and reproducible estimation of surfactant protein A mRNA copy number irrespective of the addition dosage of non-specific rat spleen RNA over the range $0-10{\mu}g$.

Mutations of katG and inhA in MDR M. tuberculosis (국내에서 분리된 다제 내성 결핵균의 katG 와 inhA 변이 다양성 및 그 빈도)

  • Lin, Hai Hua;Kim, Hee-Youn;Yun, Yeo-Jun;Park, Chan Geun;Kim, Bum-Joon;Park, Young-Gil;Kook, Yoon-Hoh
    • Tuberculosis and Respiratory Diseases
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    • v.63 no.2
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    • pp.128-138
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    • 2007
  • Backgrounds: Mutations of katG and inhA (ORF and promoter) are known to be related to isoniazid (INH) resistance of Mycobacterium tuberculosis. Because reports on these mutations in Korean isolates are limited (i.e. only the frequency of katG codon 463 was evaluated.), we tried to know the kinds of mutations of two genes and their frequencies in INH resistant Korean M. tuberculosis strains. Methods: PCR was performed to amplify katG (2,223 bp), inhA ORF (-77~897, 975 bp), and inhA promoter (-168~80, 248 bp) from 29 multidrug resistant M. tuberculosis (MDR-TB) DNAs prepared by bead beater-phenol method. Their sequences were determined and analyzed by ABI PRISM 3730 XL Analyzer and MegAlign package program, respectively. Results: All of the isolates had more than one mutation in katG or inhA gene. Twenty seven (93%) of 29 tested strains had katG mutations, which suggests that katG is a critical gene determining INH resistance of M. tuberculosis. Amino acid substitutions, such as Arg463Leu and Ser315Thr, due to point mutations of the katG were the most frequent (62.1% and 55.2%) mutations. In addition, deletion of the katG gene was frequently observed (17.2%). Analyzed Korean MDR-TB isolates also had variable inhA mutations. Point mutation of inhA promoter region, such as -15 ($C{\rightarrow}T$) was frequently found. Substitution of amino acid (Lsy8Asn) due to point mutation ($AAA{\rightarrow}AAC$) of inhA ORF was found in 1 isolate. Interestingly, 14 point mutated types that were not previously reported were newly found. While four types resulted in amino acid change, the others were silent mutations. Conclusions: Although it is not clear that the relationship of these newly found mutations with INH resistance, they show marked diversity in Korean MDR-TB strains. It also suggests their feasibility as a molecular target to supplement determining the INH resistance of clinical isolates because of the possible existence of low-level INH resistant strains.

Process Optimization of Ginseng Berry Extract Fermentation by Lactobacillus sp. Strain KYH isolated from Fermented Kimchi and Product Analysis (발효 김치로부터 분리한 Lactobacillus sp. Strain KYH를 이용한 진생베리 추출물 최적 발효 공정 확립 및 생성물의 특성 분석)

  • Ha, Yoo-Jin;Yoo, Sun-Kyun;Kim, Mee Ree
    • Journal of the East Asian Society of Dietary Life
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    • v.26 no.1
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    • pp.88-98
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    • 2016
  • The pharmacological effects of ginseng berry have been known to improve psychological function, immune activities, cardiovascular conditions, and certain cancers. It is also known that fermentation improves the bioavailability of human beneficial natural materials. Accordingly, we investigated the optimal fermentation conditions of ginseng berry extract with strain isolated from conventional foods. We also analyzed the fermentation product and its antioxidant activity. The bacterium isolated from fermented kimchi was identified as Lactobacillus sp. strain KYH. To optimize the process, fermentation was performed in a 5 L fermenter containing 3 L of ginseng berry extract at 200 rpm for 72 hr. Under optimized conditions, batch and fed-batch fermentations were performed. After fermentation, organic acids, amino acids, sugars, ginsenosides, and antioxidant activity were evaluated. The optimum fermentation conditions were determined as pH 7.0 and a temperature of $30^{\circ}C$, respectively. After fermentation, the amounts and compositions of organic acids, amino acids, sugars, ginsenosides, and antioxidant activity were altered. In comparing the distribution of ginsenosides with that before fermentation, the ginsenoside Re was a major product. However, amounts of ginsenosides Rb1, Rc, and Rd were reduced, whereas amounts of ginsenosides Rh1 and Rh2 increased. Total phenol content increased to 43.8%, whereas flavonoid content decreased to 19.8%. The DPPH radical scavenging activity and total antioxidant activity increased to 27.2 and 19.4%, respectively.

Combining Ginsenoside F1 with (-)-Epigallocatechin Gallate Synergistically Protects Human HaCaT Keratinocytes from Ultraviolet B-Induced Apoptosis (Ginsenosdie F1과 EGCG의 상승작용에 의한 자외선조사에 의한 세포 사멸 방지)

  • Tae Ryong, Lee;Si Young, Cho;Eun Hee, Lee;Myeong Hoon, Yeom;Ih-Seop, Chang
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.2
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    • pp.253-261
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    • 2004
  • Ginsenosides and green tea extracts show a variety of biomedical efficacies such as anti-aging, anti-oxidation and anti-tumor-promotion effects. (-)-Epigallocatechin-3-gallate (EGCG) has been reported to inhibit the UVB-induced apoptosis by increasing the Bcl-2-to-Bax ratio. We have previously shown that ginsenoside Fl protects human HaCaT cells from ultraviolet-B (UVB)-induced apoptosis by maintaining constant levels of Bcl-2 and Brn-3a. Here, we investigate the combined effect of ginsenoside Fl and EGCG on the protection of human HaCaT keratinocyte against UVB-induced apoptosis. When treated individually, although 5 ${\mu}$M ginsenoside Fl and 50${\mu}$M EGCG protected cells from UVB-induced apoptosis, 2${\mu}$M ginsenoside Fl or 10${\mu}$M EGCG treatment showed very little protection effect. However, cotreatement of 2${\mu}$M ginsenoside Fl and 10${\mu}$M EGCG successfully protected HaCaT cells from UVB-induced cell death. As expected, combining ginsenoside Fl and EGCG efficiently prevented UVB-induced decrease of Bcl-2 and Brn-3a expression. In addition, cotreatment with ginsenoside F1 and EGCG prevented the dephosphorylation of Rb, whereas individual treatment with ginsenoside Fl or EGCG failed to prevent the dephosphorylation of Rb even at high concentrations.

Superoxide Dismutase Gene Expression Induced by Lipopolysaccharide in Alveolar Macrophage of Rat (폐포대식세포에서 내독소 자극에 의한 Superoxide Dismutase 유전자발현의 조절 기전)

  • Park, Kye-Young;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo;Hyun, In-Gyu
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.4
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    • pp.522-534
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    • 1995
  • Background: In the pathogenesis of acute lung injury induced by lipopolysaccharide(LPS), oxygen radiclls are known to be involved in one part. Superoxide dismutase(SOD) protects oxygen radical-induced tissue damage by dismutating superoxide to hydrogen peroxide. In eukaryotic cells, two forms of SOD exist intracellularly as a cytosolic, dimeric copper/zinc-containing SOD(CuZnSOD) and a mitochondrial, tetrameric manganese-containing SOD(MnSOD). But there has been little information about SOD gene expression and its regulation in pulmonary alveolar macrophages(PAMs). The objective of this study is to evaluate the SOD gene expression induced by LPS and its regulation in PAMs of rat. Method: In Sprague-Dawley rats, PAMs obtained by broncholaveolar lavage were purified by adherence to plastic plate. To study the effect of LPS on the SOD gene expression of PAMs, they were stimulated with different doses of LPS($0.01{\mu}g/ml{\sim}10{\mu}g/ml$) and for different intervals(0, 2, 4, 8, 24hrs). Also for evaluating the level of SOD gene regulation actinomycin D(AD) or cycloheximide(CHX) were added respectively. To assess whether LPS altered SOD mRNA stability, the rate of mRNA decay was determined in control group and LPS-treated group. Total cellular RNA extraction by guanidinium thiocyanate/phenolfchlorofonn method and Northern blot analysis by using a $^{32}P$-labelled rat MnSOD and CuZnSOD cDNAs were performed. Results: The expression of mRNA in MnSOD increased dose-dependently, but not in CuZnSOD. MnSOD mRNA expression peaked at 8 hours after LPS treatment. Upregulation of MnSOD mRNA expression induced by LPS was suppressed by adding AD or CHX respectively. MnSOD mRNA stability was not altered by LPS. Conclusion: These findings show that PAMs of rat could be an important source of SOD in response to LPS, and suggest that their MnSOD mRNA expression may be regulated transcriptionally and require de novo protein synthesis without affecting mRNA stability.

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Expression of the FHIT gene Located in Chromosome 3p14.2 in Human Lung Cancer Cell Lines (폐암 세포주에서 염색체 3p14.2에 위치한 FHIT 유전자의 발현 이상에 대한 연구)

  • Kim, Cheol-Hyeon;Yoo, Chul-Gyu;Lee, Choon-Taek;Han, Sung-Koo;Shim, Young-Soo;Kim, Young-Whan
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.5
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    • pp.984-991
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    • 1998
  • Background: The 3p deletions has been shown to be the most frequent alteration in lung cancers, strongly suggesting the presence of at least one tumor suppressor gene in this chromosomal region. However, no solid candidate for the tumor suppressor gene(s) on 3p has as yet been identified. Recent attention has focused on a candidate 3p14.2 tumor suppressor gene, FHIT, which is located in a region that is homozygously deleted in multiple tumor cell lines and disrupted by the hereditary renal cell carcinoma t(3;8) chromosomal translocation breakpoint FHIT also spans FRA3B, the most common fragile sites in the human genome. In the present study, we have analyzed expression of the FHIT gene in lung cancer cell lines. Methods: RNA from 21 lung cancer cell lines (16 NSCLC, 5 SCLC) were extracted using standard procedures. Random-primed. first strand cDNAs were synthesized from total RNA and PCR amplication of coding exons 5 to 9 was performed. The RT-PCR products were electrophoresed in 1.5% ethidium bromide-stained agarose gels. Results: 12 of 21(57%) lung cancer cell lines exhibited absent or aberrant FHIT expression [7 of 16(44%) of non-small cell lung cancer and 5 of 5(100%) of small cell lung cancer cell lines]. Conclusion: The result shows that abnormal transcription of the FHIT gene is common in human lung cancer cell lines, especially in small cell lung cancer.

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Effects of Immunostimulatory CpG-Oligodeoxynucleotides on Bronchial Asthma in Rat (백서 천식에서 면역 증강성 CpG 올리고 뉴클레오티드 투여의 효과)

  • Lee, Sin-Hyung;Kim, Je-Hyeong;Jeong, Hye-Cheol;Kim, Kyung-Kyu;Jung, Ki-Hwan;Kim, Byung-Gyu;Lee, Seung-Heon;Park, Sang-Myun;Sin, Cheol;Cho, Jae-Youn;Shim, Jae-Jeong;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.1
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    • pp.12-28
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    • 2001
  • Background and Object : Immunostimulatory CpG-oligodeoxynucleotides (ISS CpG-ODN) up-regulate the $T_{H1}$-type immune response and down-regulate the $T_{H2}$-type response. This study was performed to investigate the immune response changes resulting from ISS CpG-ODN on bronchial hyperresponsiveness, eosinophilic inflammation and mucus hypersecretion in rat asthma. Materials and Methods : 10 normal controls(NC) and 26 asthmatic rats, which were generated by ovalbumin(OVA) sensitization and challenge, were studied. The asthmatic rats were randomized into 11 asthma controls(AC) and 15 in the asthma-CpG treatment group(CpG). The CpG group was administered ISS CpG-ODN intramuscularly and the AC group was administered a placebo(0.9% NaCl) on day 15 and 20. After CpG-ODN or placebo administration, we measured the IFN-${\gamma}$($T_{H1}$-type cytokine) and IL-4($T_{H2}$-type cytokine) levels in the bronchoalveolar lavage fluid(BALF), the specific airway resistance(sRaw), eosinophilic fraction in BALF, eosinophilic infiltration, goblet cell dysplasia and MUC5AC gene expression in the lung tissue. Results : In the BALF of the CpG group, the IFN-${\gamma}$ concentration was significantly high and the IL-4 concentration was significantly low when compared with the AC group. Both the sRaw and eosinophilic fraction, and infiltration into the BALF and lung tissue significantly lower in the CpG group when compared with the AC group. However, little difference in goblet cell dysplasia and MUC5AC gene expression was observed between the CpG group and the AC group. Conclusion : ISS CpG-ODN decreases bronchial hyperresponsiveness and eosinophilic inflammation in the rat asthma model through the up-regulation of the $T_{H1}$-type immune response with the down-regulation of the $T_{H2}$-type response. However, the effect of these immune response changes on mucus hypersecretion was is not remarkable in this study.

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Control of Trophoblast Gene Expression and Cell Differentiation

  • Cheon, Jong-Yun
    • 대한생식의학회:학술대회논문집
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    • 2001.03a
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    • pp.195-205
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    • 2001
  • 태반 영양배엽 (trophoblast)은 포유동물의 발생과정 중 가장 먼저 분화되는 세포로서, 자궁환경내에서 배아가 착상, 발생, 및 분화하기 위해서 반드시 필요한 태반을 형성하는 색심적인 세포이다. 영양배엽 세포의 분화과정중의 결함은 배아의 사산이나 임신질환 등의 치명적 결과를 초래한다. 하지만, 영양배엽 세포의 분화를 조절하는 분자생물학적인 메카니즘은 아직 규명되지 않고 있다. 영양배엽 세포의 분화를 조절하는 경로를 규경하기 위한 선결과제는 분화된 영양배엽 세포에서만 발현하는 많은 유전자들이 밝혀져야만 한다. 본 연구팀은 최근에 분화된 영양배엽 세포에서만 발현하는 두 종류의 새로운 유전자들을 찾았다. 한 종류는 homeobox를 보유하고 있는 조절 유전자 Psx이고, 다른 한 종류는 임신호르몬인 태반 프로락틴 라이크 단백질 유전자 PLP-C${\beta}$이다. 본 연구과제의 목표는 이들 유전자의 기능과 조절 메카니즘을 규명함으로써, 영양배엽 세포의 분화를 조절하는 조절경로를 밝히는 것이다. 이를 위하여 다음과 같은 일련의 연구를 수행할 것이다. 1) Psx 유전자가 분화된 영양배엽 세포에서만 발현케 하는 조절 메카니즘을 규명하기 위해 functional assays, in vitro footprinting, gel mobility shift assays, 생쥐형질전화, UV crosslinking, Southwestern blot 등의 방법을 통해 Psx 유전자의 cis-acting 요인과 trans-acting factor를 밝혀 분석한다. 2) 영양배엽 세포의 분화조절 경로를 규명하기 위해 random oligonuclotide library screening, DD-PCR, subtractive screening 등의 방법을 이용하여 Psx 유전자에 의해 조절되는 하부유전자를 밝힌다. 3) Psx 유전자를 knock-out시켜 영양배엽 세포가 발달 및 분화하는데 미치는 역할을 밝힌다. 4) Yeast two-hybrid screening방법을 이용하여 태반 프로락틴 유전자의 수용체를 찾아 이들의 신호전달 기전을 밝힌다. 제1차년 연구결과로서, mouse와 rat으로부터 각각 Psx 유전자의 genomic DNA를 클로닝하여, 유전자 구조를 비교한 결과, mouse Psx (mPsx2)는 4개의 exons으로 이루어져 있는 반면에, rat Psx (Psx3)는 3개의 exons으로 구성되어 있었다. 즉, rPsx3는 mPsx2의 exon1이 없었다. Notrhern blot과 in situ hybridization 분석에 의해 mouse와 rat에서 Psx 유전자가 다르게 발현 조절되는 현상을 밝혔다. 실제로 mPsx2와 rPsx3의 5'-flanking지역을 클로닝하여 염기서열 분석 결과 전혀 homology를 찾을 수 없었다. 또한, 이들 각각 promoter의 activity를 luciferase reporter를 이용하여 조사한 결과 Rcho-1 trophoblast cells에서 각기 다른 activity를 보여 주는 것을 발견하였다. Psx 유전자의 transcription start sites는 Primer extension에 의해 밝혔다. 또한 Psx2 유전자를 knock-out 시키기 위해 targeting vector를 Osdupde1에 제작하였다. 본 과제를 시작할 때 새로운 프로락틴 유전자 하나를 클로닝하여 이 유전자를 PLP-I라고 이름을 붙였다. 이 후 이 유전자 (PLP-I)는 PLP-C${\beta}$라고 이름을 붙이게 되었다. Mouse PLP-C${\beta}$ 유전자의 counterpart를 rat에서 찾아 염기서열을 비교한 결과 mouse와 rat에서 PLP-C${\beta}$유전자의 homology는 약 79% (amino acid level)였다. 본 연구과정을 통해 또 하나의 새로운 PLP-C subfamily member를 mouse로부터 클로닝 하였고, 이 유전자를 PLP-C${\gamma}$라 하였다. PLP-C${\beta}$와 PLP-C${\gamma}$의 발현 유형은 Northern blot과 in 냐셔 hybridization 분석에 의해 태반의 제한된 spongitrophoblast와 trophoblast giant cells에서만 발현하는 것을 밝혔다. 놀랍게도 이들 두 새로운 유전자는 alternative splicing에 의해 두 종류의 isoform이 있음을 밝혔다. PLP family member 유전자로서 splicing에 의한 isoforms을 보여 주는 유전자로는 PLP-C${\beta}$와 PLP-C${\gamma}$가 최초이다. 이들 isoform mRNAs의 발현 유형은 RT-PCR 방법을 이용하여 규명하였다. 또 하나의 새로운 발견은 PLP-C${\beta}$와 PLP-C${\gamma}$가 독특한 유전자 구조를 갖고 있었다. 즉, PLP-C${\beta}$는 exon3의 alternative splicing에 의해 5개 혹은 6개의 exons을 갖는 two isoforms이 생긴다. 반면에 PLP-C${\gamma}$는 exon2가 alternative splcing이 되면서 7개의 exons을 갖거나 6개의 exons을 갖는 isoforms을 만든다. 그리고, PLP-C${\gamma}$의 promoter activity를 trophoblast Rcho-l${\gamma}$ 세포주를 이용하여 PLP-C${\gamma}$ 의 1.5 kb 5'-flanking 지역이 trophoblast-specific promoter activity를 갖고 있음을 밝혔다. PLP-C${\gamma}$ 유전자의 transcription start site는 Primer extension에 의해 밝혔다. 제 1차 년도의 연구결과를 토대로, 2차년에서는 다음단계의 연구를 수행하고자 한다. 즉, 1) mPsx2와 rPsx3의 promoter를 비교분석 함으로서 mouse와 rat에서 Psx 유전자가 다르게 조절되는 메카니즘 규명, 2) Psx와 PLP-C 유전자의 promoter에 있는 cis-acting elements 탐색, 3) Psx2와 Psx3의 단백질을 이용하여 이들이 binding하는 target sequence 규명, 4) 제작한 Psx2 targeting vector를 이용하여 ES cells에서 Psx2 유전자 knock-out, 5) Psx 유전자를 과발현시키는 세포주를 만들고 Psx에 의해 조절되는 유전자 탐색, 6) 새로 밝히 PLP-C members 유전자들의 조절기전을 Rcho-1 세포주를 이용하여 여러 거지 성장인자와 다른 호르몬에 대한 반응을 탐색, 7) Psx와 PLP-C${\gamma}$ 유전자의 chromosomal mapping 등을 밝힐 것이다.

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Apoptotic Cell Death by Pectenotoxin-2 in p53-Deficient Human Hepatocellular Carcinoma Cells (종양억제유전자 p53 결손 인체간암세포에서 Pectenotoxin-2에 의한 Apoptosis 유도)

  • Shin, Dong-Yeok;Kim, Gi-Young;Choi, Byung-Tae;Kang, Ho-Sung;Jung, Jee-H.;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.17 no.10
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    • pp.1447-1451
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    • 2007
  • Through the screening of marine natural compounds that inhibit cancer cell proliferation, we previously reported that pectenotoxin-2 (PTX-2) isolated from marine sponges exhibits selective cytotoxicity against several cell lines in p53-deficient tumor cells compared to those with functional p53. However, the molecular mechanisms of its anti-proliferative action on malignant cell growth are not completely known. To further explore the mechanisms of its anti-cancer activity and to test whether the status of p53 in liver cancer cells correlates with their chemo-sensitivities to PTX-2, we used two well-known hepatocarcinoma cell lines, p53-deficient Hep3B and p53-wild type HepG2. We have demonstrated that PTX-2 markedly inhibits Hep3B cell growth and induces apoptosis whereas HepG2 cells are much more resistant to PTX-2 suggesting that PTX-2 seems to act by p53-independent cytotoxic mechanism. The apoptosis induced by PTX-2 in Hep3B cells was associated with the modulation of DNA fragmentation factor (DFF) family proteins, up-regulation of pro-apoptotic Bcl-2 family members such as Bax and Bcl-xS and activation of caspases (caspase-3, -8 and -9). Blockade of the caspase-3 activity by caspase-3 inhibitor, z-DEVD-fmk, prevented the PTX-2-induced growth inhibition in Hep3B cells. Moreover, treatment with PTX-2 also induced phosphorylation of AKT and extracellular-signal regulating kinase (ERK), but not c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MARK). Specific inhibitors of PI3K inhibitor (LY294002) and ERK1/2 inhibitor (PD98059) significantly blocks PTX-2-induced-anti-proliferative effects, whereas a JNK inhibitor (SP600125) and a p38 MAPK inhibitor (SB203580) have no significant effects demonstrating that the pro-apoptotic effect of PTX-2 mediated through activation of AKT and ERK signal pathway in Hep3B cells.