• Journal of Microbiology and Biotechnology
• /
• 제34권2호
• /
• pp.280-288
• /
• 2024

The fusogenic membrane glycoprotein (FMG) derived from the human endogenous retrovirus-W (HERV-W) exhibits fusogenic properties, making it a promising candidate for cancer gene therapy. When cells are transfected with HERV-W FMG, they can fuse with neighboring cells expressing the receptor, resulting in the formation of syncytia. These syncytia eventually undergo cell death within a few days. In addition, it has been observed that an HERV-W env mutant, which is truncated after amino acid 483, displays increased fusogenicity compared to the wild-type HERV-W env. In this study, we observed syncytium formation upon transfection of HeLa and TE671 human cancer cells with plasmids containing the HERV-W 483 gene. To explore the potential of a semi-replication-competent retroviral (s-RCR) vector encoding HERV-W 483 for FMG-mediated cancer gene therapy, we developed two replication-defective retroviral vectors: a gag-pol vector encoding HERV-W 483 (MoMLV-HERV-W 483) and an env vector encoding VSV-G (pCLXSN-VSV-G-EGFP). When MoMLV-HERV-W 483 and pCLXSN-VSV-G-EGFP were co-transfected into HEK293T cells to produce the s-RCR vector, gradual syncytium formation was observed. However, the titers of the s-RCR virus remained consistently low. To enhance gene transfer efficiency, we constructed an RCR vector encoding HERV-W 483 (MoMLV-10A1-HERV-W 483), which demonstrated replication ability in HEK293T cells. Infection of A549 and HT1080 human cancer cell lines with this RCR vector induced syncytium formation and subsequent cell death. Consequently, both the s-RCR vector and RCR encoding HERV-W 483 hold promise as valuable tools for cancer gene therapy.

• Journal of the Korean Wood Science and Technology
• /
• 제42권1호
• /
• pp.68-77
• /
• 2014

때죽나무(Styrax japonica) 수피 메탄올 추출물에서 단리된 화합물은 TLC 및 HPLC, coulmn chromatography 방법을 이용한 실리카겔 chromatography로 분리하였다. FAB-MS, NMR 분석을 통해 화합물의 구조를 구명한 결과 분자식은 $C_{27}H_{34}O_{11}Na$이고 화합물명은 styraxlignolide F로 판명되었다. 인간 정상 신장세포인 HEK293을 이용한 세포독성을 살펴본 결과, 각 추출물은 $1.0mg/m{\ell}$의 농도에서 15.2%의 낮은 세포독성을 나타내었다. AGS와 MCF-7 세포에서의 항암활성은 $CH_2Cl_2$ 가용부가 $1.0mg/m{\ell}$ 농도에서 60% 이상의 억제 활성을 나타내었다. Bcl-2 단백질 정량을 통한 항암 활성 측정 결과, $CH_2Cl_2$ 가용부가 다른 가용부 및 styraxligonlide F 보다 낮은 Bcl-2 발현량을 보였고, p53 발현량 측정에서도 $CH_2Cl_2$ 가용부가 가장 낮은 발현량을 보였다. 인간 폐암세포(A549)를 이용한 자가사멸 측정 실험에서 $CH_2Cl_2$ 가용부는 46.9%로 높은 사멸비율을 나타냈으며, 그다음으로 styraxlignolide F가 43.5%의 사멸비율을 나타내었다. $CH_2Cl_2$ 분획물은 단리물질(styraxlignolide F)보다 항암 활성 효과가 높게 나타났는데 여러 가지 물질이 시너지 효과를 나타낸 것으로 사료된다.

• Molecules and Cells
• /
• 제26권2호
• /
• pp.193-199
• /
• 2008

The pro-apoptotic Bcl-2 family member Bim acts as a sensor for apoptotic stimuli and initiates apoptosis through the mitochondrial pathway. To identify novel regulators of Bim, we employed the yeast two-hybrid system and isolated the human gene encoding macrophage migration inhibitory factor (MIF), a ubiquitously expressed proinflammatory mediator that has also been implicated in cell proliferation, the cell cycle and carcinogenesis. The interaction between MIF and Bim was confirmed by both in vitro and in vivo protein interaction assays. Intriguingly, protein complexes between MIF and the three major Bim isoforms (BimEL/BimL/BimS) could be detected in HEK293 and K562 cells, especially in cells undergoing apoptosis. Moreover, exogenous expression of MIF partially inhibited Bim-induced apoptosis in HEK293 cells. SiRNA-mediated knockdown of MIF increased apoptosis in K562 cells exposed to the chemical oxidant diamide. Endogenous MIF may regulate the pro-apoptotic activity of Bim and inhibit the release of cytochrome c from mitochondria.

• BMB Reports
• /
• 제41권10호
• /
• pp.716-721
• /
• 2008

To explore the effects of deregulated expression of the EBNA1 binding protein 2 (EBP2) on cell growth, we generated human HEK293 stable clones constitutively expressing an EBP2-EGFP fusion protein. We found both RNA and protein levels of cyclin E1, a dominant oncoprotein, were elevated in the EBP2- EGFP stable clones. These findings were confirmed by flow cytometry bivariate analysis of cyclin expression versus DNA content. Moreover, the increase in p21 expression and the specific phosphorylation at Ser1981 of ATM and Ser15 of p53 were also observed in these stable clones, and these observations may explain the failure to observe an increase in Cdk2 kinase activity. In addition, after one year of passage culture, the EBP2-EGFP stable clones tended to lose 4 to 5 chromosomes per cell when compared to that of control cells. All of these findings provide a possible link between deregulated expression of EBP2 and tumor development.

• Bulletin of the Korean Chemical Society
• /
• 제31권6호
• /
• pp.1555-1560
• /
• 2010

Quantum dots (QDs) are extensively employed for biomedical research as a fluorescence reporter and their use for various labeling applications will continue to increase as they are preferred over conventional labeling methods for various reasons. However, concerns have been raised over the toxicity of these particles in the biological system. Till date no thorough investigation has been carried out to identify the molecular signatures of QD mediated toxicity. In this study we evaluated the toxicity of CdSe, $Cd_{1-x}Zn_xS$/ZnS and CdSe/ZnS quantum dots having different spectral properties (red, blue, green) using human embryonic kidney fibroblast cells (HEK293). Cell viability assay for both short and long duration exposure show concentration material dependent toxicity, in the order of CdSe > $Cd_{1-x}Zn_xS$/ZnS > CdSe/ZnS. Genome wide changes in the expression of genes upon QD exposure was also analyzed by wholegenome microarray. All the three QDs show increase in the expression of genes related to apoptosis, inflammation and response towards stress and wounding. Further comparison of coated versus uncoated CdSe QD-mediated cell death and molecular changes suggests that ZnS coating could reduce QD mediated cytotoxicity to some extent only.

• Animal Bioscience
• /
• 제36권2호
• /
• pp.315-321
• /
• 2023

Objective: The study was conducted to investigate the dephosphorylation of Pseudomonas aeruginosa flagellin (PA FLA) by sweet potato purple acid phosphatase (PAP) and the effect of the enzyme on the flagellin-mediated inflammatory response in the A549 lung epithelial cell line. Methods: The activity of sweet potato PAP on PA FLA was assayed at different pH (4, 5.5, 7, and 7.5) and temperature (25℃, 37℃, and 55℃) conditions. The release of interleukin-8 (IL-8) and the activation of nuclear factor kappa- light-chain-enhancer of activated B cells (NF-κB) in A549 cells exposed to PA FLA treated with or without sweet potato PAP was measured using IL-8 and NF-κB ELISA kits, respectively. The activation of toll-like receptor 5 (TLR5) in TLR5-overexpressing HEK-293 cells exposed to PA FLA treated with or without sweet potato PAP was determined by the secreted alkaline phosphatase-based assay. Results: The dephosphorylation of PA FLA by sweet potato PAP was favorable at pH 4 and 5.5 and highest at 55℃. PA-FLA treated with the enzyme decreased IL-8 release from A549 cells to about 3.5-fold compared to intact PA FLA at 1,000 ng/mL of substrate. Moreover, PA-FLA dephosphorylated by the enzyme repressed the activation of NF-κB in the cells compared to intact PA FLA. The activation of TLR5 by PA-FLA was highest in TLR-overexpressing HEK293 cells at a substrate concentration of 5,000 ng/mL, whereas PA FLA treated with the enzyme strongly repressed the activation of TLR5. Conclusion: Sweet potato PAP has the potential to be a new alternative agent against the increased antibiotic resistance of P. aeruginosa and may be a new conceptual feed additive to control unwanted inflammatory responses caused by bacterial infections in animal husbandry.

• 대한한의학회지
• /
• 제43권1호
• /
• pp.33-41
• /
• 2022

Objectives: Drug-induced blockade of the human ether-à-go-go related gene (hERG) potassium ion channel causes acquired long QT syndrome, which is known to cause cardiac arrhythmias and be fatal. To establish safety evidence of herbal formulae, we evaluated the effects of 31 herbal formulae on hERG channel activity. Methods: The current through hERG channel was measured by changing the membrane voltage before and after treatment with 31 herbal formulae in HEK 293 cell overexpressing hERG channel using a whole-cell patch clamp system. The current-voltage curves and the activity curves were fitted, and the hERG activity and 50% inhibitory concentration (IC₅₀) according to each herbal formula were calculated. Results: Chokyungjongok-tang, Oncheong-eum, and Cheongsangbangpung-tang strongly inhibited the hERG activity, with IC₅₀ values of 67.67, 141.2, and 296.3 ㎍/mL, respectively. Yeonkyopaedok-san, Eunkyo-san, Ukgan-san gajinphibanha, Daegunjoong-tang (except Oryzae gluten), Insamyangyoung-tang, Banhahubak-tang, SokyungHwalhyul-tang, Jodeung-san, Hyeonggaeyeongyo-tang, and Bangkeehwangkee-tang weakly inhibited hERG activity, with IC₅₀ values ranging from 400 to 1000 ㎍/mL. The other 18 herbal formulae showed very weak hERG activity inhibition of less than 50% at the highest concentration (1000 ㎍/mL). Conclusion: This study provided safety information on cardiotoxicity by cardiac arrhythmia risk assessment of herbal formulae, and is expected to be a reference data for predicting the safety and risk of herbal formulae.

• 대한의생명과학회지
• /
• 제17권3호
• /
• pp.185-190
• /
• 2011

Adenovirus type 5 (Ad5) vectors have been used for gene transfer to a wide variety of cell types in vivo and in vitro. The advantages of adenovirus vectors include the high titer of virus readily obtained in large scale preparations, their ability to transduce dividing and non dividing cells, and the high level of transgene expression. Since adenovirus vectors do not integrate in host cell DNA, there is a lack of insertional mutagenesis. However, many human tumor cells lack expression of the adenovirus 5 receptors and contain areas of hypoxia. In order to identify the pattern of replication and gene expression of oncolytic adenovirus in hypoxic condition, multiple different fiber modified Ads (Ad5F/S11, Ad5F/S35, Ad5F/K7, Ad5F/K21, and Ad5F/RGD) was compared. The replication of all fiber modified adenovirus was inhibited in hypoxic condition in HEK 293 cells, but gene expression has variety on different tumor cell lines and the level of coxackievirus and adenovirus receptor (CAR) expression. These data suggest that CAR expression pattern and hypoxic condition of tumor are considered for optimal oncolytic adenovirus application.

• 한국약용작물학회지
• /
• 제15권6호
• /
• pp.398-404
• /
• 2007

본고에서는 초고압 추출 공정의 활성 증진 효과를 알아보기 위해 복분자의 면역활성 실험을 실시하였는데 그 결과는 아래와 같다. 인간의 정상 신장세포인 HEK293을 이용한 세포 독성은 추출물은 1.0 $mg/m{\ell}$의 농도에서 최고 19.5%의 세포독성을 나타냈다. 항암활성은 AGS와 A549 암세포를 이용하였는데, 초고압을 실시할 경우 1.0 $mg/m{\ell}$의 농도에서 80%이상의 높은 억제활성을 보였으며, 암세포의 생육활성에 대한 정상 세포의 세포독성의 비로 나타낸 선택적 사멸도는 모든 고농도에서 모두 3 이상으로 나타났다. 모든 처리구 중 15분간 초고압 추출한 것이 가장 높은 활성을 보였으나 5분간 초고압 추출한 것과 큰 차이가 나지 않아 5분간 초고압 추출을 실시하는 것이 효율적인 것으로 보인다. B cell과 T cell을 이용한 면역세포의 생육은 배양 6일째에 15분간 초고압으로 추출한 처리구에서 각각 $13.5{\times}10^4cells/m{\ell}$, $14.6{\times}10^4cells/m{\ell}$로 가장 높은 세포농도를 나타냈다. 면역세포를 이용한 cytokin의 분비량 측정실험에서는 HPE15 추출물이 배양 시간에 따른 cytokine의 분비가 가장 높게 나타나는 것을 확인할 수 있었다. 각 세포의 $TNF-{\alpha}$와 IL-6의 분비량은 6일째 최고의 분비량을 나타내었다. 또한 NK cell의 면역활성은 모든 추출물에서 배양 시간에 따라 유의적으로 증가하는 것을 확인하였다. 그 중 HPE15 추출물에서 B cell의 경우 $15.8{\times}10^4cells/m{\ell}$, T cell의 경우 $14.8{\times}10^4cells/m{\ell}$으로 가장 높은 생육 활성을 나타내었다. 본 실험 결과를 통하여 초고압으로 인해 기존의 추출 방법으로는 추출되지 않았던 유용생리활성 물질들이 초고압으로 조직과 세포막 파괴로 인해 유용성분의 용출량이 증가하고 새로운 물질의 용출로 인해 높은 활성을 나타낸 것으로 판단되었다.

• 분석과학
• /
• 제26권1호
• /
• pp.106-112
• /
• 2013

Phosphodiesterase (PDE)는 세포내의 cAMP를 분해하는 효소로 세포의 신호 전달에 중요한 기능을 수행하는 것으로 알려져 왔다. 각각의 PDE들은 N-말단의 서열을 통해 세포 내 특정 부위로 이동되어 기능을 수행한다. 이전의 연구를 통해 바다달팽이인 군소에서 새롭게 클로닝된 ApPDE4 long-form이 원형질막과 시냅스전 뉴런의 말단에 발현됨을 확인하였다. 그러나, 현재까지 이러한 세포내 작용부위로의 이동, 즉 타겟팅(targeting)에 필요한 최소부위가 어디인지, 이러한 타겟팅이 세포에 미치는 영향은 무엇인지는 보고되지 않았다. 따라서, 본 연구에서는 이를 알아보기 위해 첫째, 원형질막으로 타겟팅에 필요한 최소부위를 알아 보고자 하였다. 이를 위해 다양한 결실돌연변이체를 제작하고, 이들의 이동과 분포를 확인한 결과, N-말단 13개의 아미노산만으로도 원형질막으로 타기팅에 충분하다는 것을 확인할 수 있었다. 또한, ApPDE4 N-말단의 20개 아미노산을 mRFP에 융합해서 만든 ApPDE4(N20)-mRFP를 HEK293T 세포에 과발현시킨 결과, 기포(bleb)가 생성되는 세포의 비정상적인 형태 변화가 관찰 되었다. 이러한 형태적 변화는 ApPDE4가 원형질막으로 타겟팅되는 것과 관련이 있었다. 대표적인 인지질의 하나인 PI4,$5P_2$에 선택적으로 결합함으로써 원형질막으로 타겟팅되는 단백질인 mRFP-$PLC{\delta}1$(PH)의 과발현도 ApPDE4(N20)-mRFP와 비슷한 세포의 형태적 변화가 유도됨을 확인할 수 있었다. ApPDE4의 N-말단은 PI4,$5P_2$와 같은 인지질과의 결합으로 원형질막으로 타겟팅될 수 있고, 형태적 변화를 유도하는 가능성을 제시한다.