• Molecules and Cells
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• 제39권8호
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• pp.631-638
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• 2016

Glutathione peroxidase 3 (GPx3), an antioxidant enzyme, acts as a modulator of redox signaling, has immunomodulatory function, and catalyzes the detoxification of reactive oxygen species (ROS). GPx3 has been identified as a tumor suppressor in many cancers. Although hyper-methylation of the GPx3 promoter has been shown to down-regulate its expression, other mechanisms by which GPx3 expression is regulated have not been reported. The aim of this study was to further elucidate the mechanisms of GPx3 regulation. GPx3 gene analysis predicted the presence of ten glucocorticoid response elements (GREs) on the GPx3 gene. This result prompted us to investigate whether GPx3 expression is regulated by the glucocorticoid receptor (GR), which is implicated in tumor response to chemotherapy. The corticosteroid dexamethasone (Dex) was used to examine the possible relationship between GR and GPx3 expression. Dex significantly induced GPx3 expression in H1299, H1650, and H1975 cell lines, which exhibit low levels of GPx3 expression under normal conditions. The results of EMSA and ChIP-PCR suggest that GR binds directly to GRE 6 and 7, both of which are located near the GPx3 promoter. Assessment of GPx3 transcription efficiency using a luciferase reporter system showed that blocking formation of the GR-GRE complexes reduced luciferase activity by 7-8-fold. Suppression of GR expression by siRNA transfection also induced down-regulation of GPx3. These data indicate that GPx3 expression can be regulated independently via epigenetic or GR-mediated mechanisms in lung cancer cells, and suggest that GPx3 could potentiate glucocorticoid (GC)-mediated anti-infla-mmatory signaling in lung cancer cells.

• 한국식품조리과학회지
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• 제28권2호
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• pp.175-182
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• 2012

In this study, antibacterial activity and cytotoxicity of the extracts from pericarp and seed of $Vitis$ $coignetiea$, which were extracted with 0.1% HCl-60% ethanol, were analyzed. The antibacterial activity of the extracts was determined by paper disc diffusion method against food spoilage and food-borne pathogens. The pericarp extract showed high antibacterial activity against $Bacillus$ $cereus$, $Escherichia$ $coli$ O157:H7, and $Pseudomonas$ $aeruginosa$, and the seed extract represented the high antibacterial activity against $B.$ $cereus$, $E.$ $coli$ O157:H7, and $Staphylococcus$ $aureus$. The cytotoxicity of the $Vitis$ $coignetiea$ extract against human cancer cells was determined using the MTT assay and SRB assay. The pericarp extract represented strong growth-inhibition activity against G361 and Hep3B cells and the seed extract greatly inhibited the growth of HeLa and G361 cells in the MTT assay. In addition, the pericarp extract displayed a high inhibition activity against the growth of AGS cells and the seed extract greatly inhibited the growth of HeLa, Hep3B, and MCF7 cells in the SRB assay. Especially, the cytotoxicities of the seed extract against HeLa were significantly higher than those of the extract against other cancer cells at all test concentrations. This study demonstrates that the extract from pericarp and seed of $Vitis$ $coignetiea$ possess high antibacterial activity and cytotoxicity.

• 생명과학회지
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• 제23권7호
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• pp.947-954
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• 2013

Wnt/${\beta}$-catenin 신호는 세포의 운명 결정, 증식, 분화 등을 조절하는 척추 동물 배아 발생과 성체의 항상성 유지에 필수적인 세포신호전달경로이다. 이러한 Wnt/${\beta}$-catenin의 비정상적인 조절에 의해 선천적 기형, 암, 대사질환 등을 비롯한 다양한 질병이 유발된다. 이를 바탕으로 최근 Wnt/${\beta}$-catenin 신호의 조절을 통한 암을 비롯한 질병의 치료를 위한 연구가 활발히 진행되고 있다. 따라서 Wnt/${\beta}$-catenin 신호를 조절하는 인자의 발굴 및 자세한 작용 기전에 대한 연구가 절실히 필요하다. 본 총설에서는 최근 새롭게 알려진 Wnt/${\beta}$-catenin 신호 조절 기작에 대해 설명하고, 현재까지 알려진 Wnt/${\beta}$조절하는 인산화 효소(kinase)의 종류와 작용 기전과 새로운 약물 타겟으로 전망을 알아 보고자 한다.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.445-450
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• 1996

Gelatinase A is a member of the matrix metalloproteinases that play an important role in cancer invasion and metastasis. In the course of screening gelatinase A inhibitors from microbial sources, a fungal strain PT-262 showed a strong inhibitory activity. The strain was identified as Chaunopycnis alba on the basis of its morphological characteristics. The inhibitor was isolated from acetone extract of mycelial cake by sequential chromatographies on MCI-gel, Sephadex LH-20, and a reverse-phase HPLC column. The purified inhibitor was identified as pyridoxatin by its physico-chemical properties and spectroscopic analysis. Pyridoxatin is not a peptide analog and has cyclic hydroxamic acid moiety. It inhibited activated gelatinase A with an $IC_{50}$ value of 15.2 ${\mu}M$ using fluorescent synthetic peptide. It also had a strong cytotoxicity against human cancer cell lines in vitro. Furthermore, this compound inhibited DNA synthesis with an $IC_{50}$ value of 2.92 ${\mu}M$ in PC-3 prostate cancer cells by [$^3H$]thymidine incorporation assay.

• Archives of Pharmacal Research
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• 제28권7호
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• pp.823-828
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• 2005

Multidrug resistance (MDR) is one of the most significant obstacles in cancer chemotherapy. One of the mechanisms involved in the development of MDR is the over-expression of P-glycoprotein (P-gp). It is widely known that natural compounds found in vegetables, fruits, plant-derived beverages and herbal dietary supplements not only have anticancer properties, but may also modulate P-gp activity. Therefore, the purpose of this investigation was to examine the effects of naturally occurring products on P-gp function in human breast cancer cell lines, MCF-7 (sensitive) and MCF-7/ADR (resistant). The accumulation of daunomycin (DNM), a P-gp substrate, was greater in the sensitive cells compared to the resistant cells, while the efflux of DNM was higher in the resistant cells compared to the sensitive cells over a period of 2h. The $IC_{50}$ value of DNM in the resistant cells was about 22 times higher than that in the sensitive cells, indicating an over-expression of P-gp in the resistant cells, MCF-7/ADR. All of the compounds tested, with the exception of fisetin, significantly decreased the $IC_{50}$ value of DNM. Biochanin A showed the greatest increase in $[^3H]-DNM$ accumulation, increasing by $454.3{\pm}19.5%$ in the resistant cells, whereas verapamil, the positive control, increased the accumulation by $229.4{\pm}17.6%$. Also, the accumulation of $[^3H]-DNM$ was increased substantially by quercetin and silymarin while it was reduced by fisetin. Moreover, biochanin A, silymarin, and naringenin significantly decreased DNM efflux from MCF-7/ADR cells compared with the control. These results suggest that some flavonoids such as biochanin A and silymarin may reverse MDR by inhibiting the P-gp function.

• BMB Reports
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• 제56권3호
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• pp.184-189
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• 2023

Ovarian cancer (OC) is the most common gynecological malignancy worldwide, and chemoresistance occurs in most patients, resulting in treatment failure. A better understanding of the molecular processes underlying drug resistance is crucial for development of efficient therapies to improve OC patient outcomes. Circular RNAs (circRNAs) and ferroptosis play crucial roles in tumorigenesis and resistance to chemotherapy. However, little is known about the role(s) of circRNAs in regulating ferroptosis in OC. To gain insights into cisplatin resistance in OC, we studied the ferroptosis-associated circRNA circSnx12. We evaluated circSnx12 expression in OC cell lines and tissues that were susceptible or resistant to cisplatin using quantitative real-time PCR. We also conducted in vitro and in vivo assays examining the function and mechanism of lnc-LBCSs. Knockdown of circSnx12 rendered cisplatin-resistant OC cells more sensitive to cisplatin in vitro and in vivo by activating ferroptosis, which was at least partially abolished by downregulation of miR-194-5p. Molecular mechanics studies indicate that circSnx12 can be a molecular sponge of miR-194-5p, which targets SLC7A11. According to our findings, circSnx12 ameliorates cisplatin resistance by blocking ferroptosis via a miR-194-5p/SLC7A11 pathway. CircARNT2 may thus serve as an effective therapeutic target for overcoming cisplatin resistance in OC.

• Mycobiology
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• 제50권5호
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• pp.389-398
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• 2022

Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC₅₀ value of lower than 10 ㎍/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anticancer compound.

• Mycobiology
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• 제51권4호
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• pp.246-255
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• 2023

Genus Penicillium comprising the most important and extensively studied fungi has been well-known as a rich source of secondary metabolites. Our study aimed to analyze and investigate biological activities, including in vitro anti-cancer, anti-inflammatory and anti-diabetic properties, of metabolites from a marine-derived fungus belonging to P. levitum. The chemical compounds in the culture broth of P. levitum strain N33.2 were extracted with ethyl acetate. Followingly, chemical analysis of the extract leaded to the isolation of three ergostane-type steroid components, namely cerevisterol (1), ergosterol peroxide (2), and (3β,5α,22E)-ergosta-6,8(14),22-triene-3,5-diol (3). Among these, (3) was the most potent cytotoxic against human cancer cell lines Hep-G2, A549 and MCF-7 with IC₅₀ values of 2.89, 18.51, and 16.47 ㎍/mL, respectively, while the compound (1) showed no significant effect against tested cancer cells. Anti-inflammatory properties of purified compounds were evaluated based on NO-production in LPS-induced murine RAW264.7 macrophages. As a result, tested compounds performed diverse inhibitory effects on NO production by the macrophages, with the most significant inhibition rate of 81.37±1.35% at 25 ㎍/mL by the compound (2). Interestingly, compounds (2) and (3) exhibited inhibitory activities against pancreatic lipase and α-glucosidase enzymes in vitro assays. Our study brought out new data concerning the chemical properties and biological activities of isolated steroids from a P. levitum fungus.

• 한국약용작물학회지
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• 제13권4호
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• pp.199-205
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• 2005

강원도 산지에서 채취한 만병초 잎의 70% ethanol 추출물과 다른 유기용매 분획 과정을 통한 3가지의 분획물에 대한 in vitro에서의 정상세포에 대한 세포독성과 유전독성, 여러 암세포에 대한 항암 기능, 면역세포에 대한 면역기능 등을 조사하여 다음과 같은 결과를 얻었다 1. 만병초 잎의 EtOH 추출물과 각 용매 분획물 들의 사람의 정상 세포인 HEL 299와 Chang에 대한 세포 독성을 SRB assay로 측정한 결과, 대부분의 시료 0.5 mg/ml 이하의 농도에서 35% 이하의 세포 독성이 나타났다. 2. 만병초 잎의 70% EtOH 추출물 및 각 다른 용매 분획물만 처리한 정상 세포에 대한 유전독성을 comet assay에서 측정한 결과, 양성 대조구 $(10^{-2}M,\;H_2O_2)$과 비교시, 가장 높은 농도인 1 mg/ml의 농도에서 1/3 이하의 낮은 DNA damage가 관찰되었다. 이것은 세포독성과 관련하여 대부분의 각 시료가 세포 DNA에 대하여 매우 약한 손상만 일으키는 것이 확인되었다. 3. 사람의 암세포에 대한 SRB 및 MTT assay를 이용한 만병초의 잎의 모든 시료의 1 mg/ml의 농도의 70% EtOH의 추출물은 실험대상인 모든 사람의 암세포에 대하여 80% 이상의 항암 기능을, EtOAc fr.는 모든 암세포에 대하여 가장 높은 농도인 1 mg/ml에서 70% 이상의 높은 억제 활성이 보인 결과로 부터 유효한 성분이 역시 EtOAc fr.에 함유되어 있을 것을 시사하였다. 4. 만병초 잎 추출물의 면역세포 생육에 대한 조사에서 사람의 B-cell과 T-cell에 대하여 0.5 mg/ml의 농도에서 배양 3일째에 BuOH fr.에서 대조구와 비교시 1.6배 정도의 생육 촉진활성을 보였다. 5. SCGE를 통해 $H_2O_2$로 유도된 산화적 손상에 대한 만병초 잎 추출물과 분획물들의 유전독성 억제 기능은 EtOAc fr.이 $100\;{\mu}g/ml$ 농도에서 대조구 대비 68.5%의 가장 높은 산화손상 억제율을 보였으며 BuOH fr.에서도 강한 유전독성 억제기능이 있음이 확인되었다. 그러나 수용액 분획은 매우 약한 유전독성 억제 활성을 보여 각 분획의 특성이 다양함을 알 수 있었다.

• Radiation Oncology Journal
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• 제17권2호
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• pp.151-157
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• 1999

목적 : HL60 세포주에서 PMA(phorbol 12-myrisate 13-acetate) 및 DMSO(dlmethyisulfoxlde) 에 의해 분화가 유도될 때 감소되는 특성을 보이는 K872 클론에 대한 염기 서열, 조직 분포, 단백 분리 등을 시행하였다. 재료 및 방법 QIA plasmid extraction kit(Qiagen GmbH, Germany)를 이용하여 사람의 모유두 세포 pBluescript phagemid cDNA library로부터 K872 클론을 추출하였다. Sanger's dideoxy nucleotide chain-termination method을 이용하여, 추출한 K872 클론의 염기 서열을 분석하였다. BLAST(Basic Local Alignment Search Tools) 프로그램으로 유전자은행의 염기 서열과의 상동성을 검색하였다. K872 클론으로 만든 probe로 다양한 인간 조직 및 암세포주로부터 분리한 RNA에 대하여 nothern blot을 시행하였다. His-Patch Thifusion expression system을 이용하여 대장균 배지에 0.1mM IPTG(Isopropyl-$\beta$-thlogalactopyranoslde) 를 첨가해서 결합단백의 유전자 발현을 유도하였다. 결합단백이 함유된 용출액을 SDS-PAGE에 걸어서 발현된 단백을 확인하였다. 결과 : K872 클론은 675개의 코딩 영역과 280개의 코딩과 관련없는 영역으로 구성된 1006개의 염기로 구성됨을 관찰하였다. 해독틀로 추정되는 부분은 시작 코돈을 포함하여 길6개의 아미노산을 형성하고 단백 산물의 분자량은 25,560 Da으로 추정되었다. 추정 아미노산 배열은 쥐의 glutathlone S-transferase kappa 1(rGSTKl) 의 아미노산 배열과 70$\%$의 상동성을 보였다. nothern blot에 따른 발현 양상은 심장, 수의근, 말초혈액 백혈구 등의 조직에서 높은 발현을 보였으며 방사선 내성과 관련지어 볼 때 대장암 및 흑색종 세포주에서 발현이 높았던 점은 특기할 만하였다. 결론 : 상동성 검색 결과 K872 유전자는 항암제 및 방사선 내성과 관련이 있는 rGSTK1에 대한 사람의 상동유전자로 사료되며 향후 이와 관련한 기능 분석이 필요할 것으로 사료된다