• 생명과학회지
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• 제21권3호
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• pp.349-357
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• 2011

EGFR kinase의 활성을 억제할 수 있는 억제제는 암뿐만이 아니라 성장성 질환에도 효과적인 치료제가 될 수 있다. 본 연구는 새로운 퀴나졸린계 물질인 화합물 63013과 63033의 EGFR kinase 활성억제 효과를 분석하였다. 이들 물질들은 기존의 디알콕시퀴나졸린의 용해성을 증가시키기 위하여 [1,4]-다이옥시노 퀴나졸린 구조를 가지며 알콕시 곁사슬로 연결되어있다. 화합물 63013과 63033은 A431 인간 피부암세포에서 EGF에의해 유도되는 EGFR의 kinase 활성을 저해, 세포 내에서 EGFR 신호체계에 관여하는 MEK1/2, MAPK p44/42, AKT, STAT3과 같은 하위 분자들의 활성저해 효과를 유도하였다. 이러한 활성저해 효과는 현재 상용화되어 있는 Gefitinib (Iressa$^{(R)}$)와의 비교연구에서 화합물 63013과 63033이 보다 더 낮은 처리 농도에서 EGFR kinase의 활성을 저해하며 암세포의 성장을 억제함을 관찰 할 수 있었다. 따라서 본 연구는 이들 신규 물질들의 EGFR-연관 질환에 대한 EGFR kinase 선택적 억제제로서의 이용 가능성을 제시하고 있다.

• Molecules and Cells
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• 제45권5호
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• pp.329-342
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• 2022

The liver is the predominant metastatic site for pancreatic cancer. However, the factors that determine the liver metastasis and the specific molecular mechanisms are still unclear. In this study, we used human pancreatic cancer cell line Hs766T to establish Hs766T-L3, a subline of Hs766T with stable liver metastatic ability. We performed RNA sequencing of Hs766T-L3 and its parental cell line Hs766T, and revealed huge differences in gene expression patterns and pathway activation between these two cell lines. We correlated the difference in pathway activation with the expression of the four core transcriptional factors including STAT1, NR2F2, GATA2, and SMAD4. Using the TCGA database, we examined the relative expression of these transcription factors (TFs) in pan-cancer and their relationship with the prognosis of the pancreatic cancer. Among these TFs, we considered GATA2 is closely involved in tumor metastasis and may serve as a potential metastatic driver. Further in vitro and in vivo experiments confirmed that GATA2-mediated transcriptional activation of Notch3 promotes the liver metastasis of Hs766T-L3, and knockdown of either GATA2 or Notch3 reduces the metastatic ability of Hs766T-L3. Therefore, we claim that GATA2 may serve as a metastatic driver of pancreatic cancer and a potential therapeutic target to treat liver metastasis of pancreatic cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.2689-2698
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• 2013

Epithelial-to-mesenchymal transition (EMT) is a collection of events that allows the conversion of adherent epithelial cells, tightly bound to each other within an organized tissue, into independent fibroblastic cells possessing migratory properties and the ability to invade the extracellular matrix. EMT contributes to the complex architecture of the embryo by permitting the progression of embryogenesis from a simple single-cell layer epithelium to a complex three-dimensional organism composed of both epithelial and mesenchymal cells. However, in most tissues EMT is a developmentally restricted process and fully differentiated epithelia typically maintain their epithelial phenotype. Recently, elements of EMT, specially the loss of epithelial markers and the gain of mesenchymal markers, have been observed in pathological states, including epithelial cancers. Increasing evidence has confirmed its presence in human colon during colorectal carcinogenesis. In general, chronic inflammation is considered to be one of the causes of many human cancers including colorectal cancer(CRC). Accordingly, epidemiologic and clinical studies indicate that patients affected by ulcerative colitis and Crohn's disease, the two major forms of inflammatory bowel disease, have an increased risk of developing CRC. A large body of evidence supports roles for the SMAD/STAT3 signaling pathway, the NF-kB pathway, the Ras-mitogenactivated protein kinase/Snail/Slug and microRNAs in the development of colorectal cancers via epithelial-tomesenchymal transition. Thus, EMT appears to be closely involved in the pathogenesis of colorectal cancer, and analysis refered to it can yield novel targets for therapy.

• 대한임상검사과학회지
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• 제47권4호
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• pp.161-167
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• 2015

정상인에서 장내세균은 숙주의 면역이나 영양 흡수를 돕지만, 때로는 기회감염균으로서 그들을 위협하기도 한다. 그 중 절대 혐기성 세균인 Bacteroides fragilis는 분비되는 장독소(enterotoxin)인 Bacteroides fragilis toxin (BFT)의 유무에 따라 non-enterotoxigenic B. fragilis (NTBF)와 enterotoxigenic B. fragilis (ETBF)로 나뉜다. ETBF는 가축 및 사람에서 설사 질환 및 대장 질환을 유발한다 그러나 때때로 ETBF를 가지고 있으나 증상이 없는 사람도 존재한다. ETBF는 염증성 설사 질환, 여행자 설사 환자의 대변에서 검출되어 주목 받고 있다. 또한, 몇몇 연구를 통해 inflammatory bowel disease (IBD)나 대장염 및 대장암 환자에서 ETBF가 증가한다는 것이 밝혀졌다. 일반 C57BL/6 마우스 및 germ-free 마우스, multiple intestinal neoplasia (Min) 마우스, 토끼, Mongolian gerbil 등 여러 동물 모델에서 ETBF가 IBD나 대장염, 대장암을 유발 또는 촉진한다는 것이 발표되었다. ETBF의 유일한 병원성 인자인 BFT는 E-cadherin의 분절을 유도하여 장상피 세포의 투과성을 높인다. 이어서 ${\beta}$-catenin 신호전달계가 활성화하여 장상피세포의 증식이 증가한다. 또한 ETBF의 감염은 일반 마우스에서 급성이나 만성의 대장염을 일으키고 Min 마우스에서 종양 형성을 촉진한다. 이는 Stat3에 의존한 $T_H17$ 면역반응의 활성화를 통해 일어난다. 현재 ETBF의 검출 방법에는 크게 BFT toxin assay와 몇 가지 PCR 방법이 있다. 최근 real-time PCR과 같은 분자진단학적 기법의 발달로 일반적인 PCR보다 더 정확한 ETBF의 검출이 가능하게 되었다. 이것을 이용하여 앞으로 실제 임상에서 ETBF와 대장염 및 대장암의 발달 관계에 대한 심도 깊은 연구가 이뤄질 것으로 본다.

• Natural Product Sciences
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• 제27권3호
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• pp.151-160
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• 2021

Under some pathological conditions such as osteoarthritis, matrix metalloproteinases (MMPs) including MMP-13 have an important role in degrading cartilage materials. When the regulatory effects of some herbal extracts on MMP-13 expression were examined to evaluate the cartilage-protective potential, the ethanol extract of the radix of Viscum album was found to strongly downregulate MMP-13 induction in IL-1β-treated chondrocytes, SW1353 cells. Based on this finding, activity-guided separation was carried out, which yielded five constituents identified as 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl)heptane (1), hesperetin-7-glucoside (2), syringin (3), homoflavoyadorinin B (4), and 4,4'-dihydroxy-3,6'-dimethoxychalcone-2'-glucoside (5). Of these, 1 and 5 significantly inhibited MMP-13 expression in SW1353 cells, with 5 being the most potent. Compound 5, a chalcone derivative, showed the downregulation of MMP-13 at 20 - 100 μM. The mechanism study revealed that 5 exerted MMP-13 down-regulatory action, at least in part, by interrupting the signal transducer and activator of transcription 1 (STAT1) activation pathway. Furthermore, this compound protected against cartilage degradation in an IL-1-treated rabbit cartilage explant culture. All these findings demonstrated for the first time that Viscum album and its constituents, especially chalcone derivative (5), possessed cartilage-protective activity. These natural products may have the potential for alleviating cartilage degradation.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.53-56
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• 2000

효모를 이용하여 높은 생산성으로 고농도의 erythritol을 생산하기 위하여 ‘세포 성장단계’와 ‘erythritol 생성단계’로 나누어 2 단계 유가식 배양을 수행하였다. 세포 성장 단계에서는 pH-stat 유가식 배양을 수행하여 3.62 g/L-H의 생산성으로 76 g/L의 균체 농도를 얻을 수 있었다. pH-stat 유가식 배양을 수행하여 고농도의 균체 농도를 얻은 후에 멸균되지 않은 분말형태의 glucose를 발효조에 400 g/L가 되도록 공급하여 세포에 osmotic stress를 가해준 결과 41%의 수율로 187 g/L의 erythritol을 생산할 수 있었으며, 이때의 생산성은 2.79 g/L-h로서 기존에 보고된 어느 결과보다도 높은 값을 얻을 수 있었다. Production phase에서 erythritol 생산에 대한 삼투압의 영향을 알아 본 결과 glucose의 농도가 증가할 수록 생성되는 erythritol 농도가 증가하였으며 세포 농도에 따른 erythritol 생산 수율은 큰 차이는 없었으나 세포 농도가 증가할수록 이에 비례하여 erythritol 생산성이 크게 증가하였다. Erythritol 생산에서 용존 산소량에 관계없이 butyric acid가 생성되었으며 40%의 DO 미만에서는 citric acid가 생성되고, 40% 이상의 DO에서는 gluconic acid가 생성되어 용존 산소량에 의하여 metabolic shift가 유도되었다. 고 농도의 glucose 첨가 후 용존 산소량을 20%로 조절하면서 pH를 3.0으로 낮춘 결과 citrate synthetase의 활성이 억제되어 citric acid가 생성되지 않았으며 gluconic acid 농도는 $KH_2PO_4$에 의하여 증가하고 $MgSO_4{\cdot}7H_2O$ 또는 $(NH_4)_2SO_4$에 의하여 감소되었다. Butyric acid 농도는 $KH_2PO_4$ 또는 $(NH_4)_2SO_4$에 의하여 감소되었으며 synergic effect에 의하여 억제되었다

• BMB Reports
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• 제48권3호
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• pp.127-128
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• 2015

Tumor metastasis involves circulating and tumor-initiating capacities of metastatic cancer cells. Hepatic TM4SF5 promotes EMT for malignant growth and migration. Hepatocellular carcinoma (HCC) biomarkers remain unexplored for metastatic potential throughout metastasis. Here, novel TM4SF5/CD44 interaction-mediated self-renewal and circulating tumor cell (CTC) capacities were mechanistically explored. TM4SF5-dependent sphere growth was correlated with $CD133^+$, $CD24^-$, ALDH activity, and a physical association between CD44 and TM4SF5. The TM4SF5/CD44 interaction activated c-Src/STAT3/ Twist1/ B mi1 signaling for spheroid formation, while disturbing the interaction, expression, or activity of any component in this signaling pathway inhibited spheroid formation. In serial xenografts of less than 5,000 cells/injection, TM4SF5-positive tumors exhibited locally-increased CD44 expression, suggesting tumor cell differentiation. TM4SF5-positive cells were identified circulating in blood 4 to 6 weeks after orthotopic liver-injection. Anti-TM4SF reagents blocked their metastasis to distal intestinal organs. Altogether, our results provide evidence that TM4SF5 promotes self-renewal and CTC properties supported by $CD133^+/TM4SF5^+/CD44^+^{(TM4SF5-bound)}/ALDH^+/CD24^-$ markers during HCC metastasis.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2219-2225
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• 2015

SHP1 negatively regulates the Janus kinase 2/signal transducer and activator of transcription (JAK2/STAT) signaling pathway, which is constitutively activated in myeloproliferative neoplasms (MPNs) and leukemia. Promoter hypermethylation resulting in epigenetic inactivation of SHP1 has been reported in myelomas, leukemias and other cancers. However, whether SHP1 hypermethylation occurs in MPNs, especially in Chinese patients, has remained unclear. Here, we report that aberrant hypermethylation of SHP1 was observed in several leukemic cell lines and bone marrow mononuclear cells from MPN patients. About 51 of 118 (43.2%) MPN patients including 23 of 50 (46%) polycythaemia vera patients, 20 of 50 (40%) essential thrombocythaemia and 8 of 18 (44.4%) idiopathic myelofibrosis showed hypermethylation by methylation-specific polymerase chain reaction. However, SHP1 methylation was not measured in 20 healthy volunteers. Hypermethylation of SHP1 was found in MPN patients with both positive (34/81, 42%) and negative (17/37, 45.9%) JAK2V617F mutation. The levels of SHP1 mRNA were significantly lower in hypermethylated samples than unmethylated samples, suggesting SHP1 may be epigenetically inactivated in MPN patients. Furthermore, treatment with 5-aza-2'-deoxycytidine (AZA) in K562 cells showing hypermethylation of SHP1 led to progressive demethylation of SHP1, with consequently increased reexpression of SHP1. Meanwhile, phosphorylated JAK2 and STAT3 were progressively reduced. Finally, AZA increased the expression of SHP1 in primary MPN cells with hypermethylation of SHP1. Therefore, our data suggest that epigenetic inactivation of SHP1 contributes to the constitutive activation of JAK2/STAT signaling. Restoration of SHP1 expression by AZA may contribute to clinical treatment for MPN patients.

• Molecular & Cellular Toxicology
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• 제5권4호
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• pp.354-363
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• 2009

Cytotoxic Nitric oxide (NO) overproduced by inducible NO Synthase (iNOS or NOS2), which was induced in inflammatory reactions and immune responses directly or indirectly affects the functions as host defense and can cause normal tissue damage. Microarray analysis was performed to identify gene profiles of both NO-dependent and -independent transcripts in RAW 264.7 macrophages that use selective NOS2 inhibitors aminoguanidine ($100\;{\mu}M$) and L-canavanine (1 mM). A total of 3,297 genes were identified that were up- or down-regulated significantly over 2-fold in lipopolysaccharide (LPS)-treated macrophages. NO-dependency was determined in the expressed total gene profiles and also within inflammatory conditions-related functional categories. Out of all the gene profiles, 1711 genes affected NO-dependently and -independently in 567 genes. In the categories of inflammatory conditions, transcripts of 16 genes (Pomp, C8a, Ifih1, Irak1, Txnrd1, Ptafr, Scube1, Cd8a, Gpx4, Ltb, Fasl, Igk-V21-9, Vac14, Mbl1, C1r and Tlr6) and 29 geneas (IL-1beta, Mpa2l, IFN activated genes and Chemokine ligands) affected NO-dependently and -independently, respectively. This NO dependency can be applied to inflammatory reaction-related functional classifications, such as cell migration, chemotaxis, cytokine, Jak/STAT signaling pathway, and MAPK signaling pathway. Our results suggest that LPS-induced gene transcripts in inflammation or infection can be classified into physiological and toxic effects by their dependency on the NOS2-mediated NO release.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1109-1114
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• 2021

Chlamydia pneumoniae is a type of pathogenic gram-negative bacteria that causes various respiratory tract infections including asthma. Chlamydia species infect humans and cause respiratory infection by rupturing the lining of the respiratory which includes the throat, lungs and windpipe. Meanwhile, the function of interleukin-4 (IL-4) in Ch. pneumoniae respiratory infection and its association with the development of airway hyperresponsiveness (AHR) in adulthood and causing allergic airway disease (AAD) are not understood properly. We therefore investigated the role of IL-4 in respiratory infection and allergy caused by early life Chlamydia infection. In this study, Ch. pneumonia strain was propagated and cultured in HEp-2 cells according to standard protocol and infant C57BL/6 mice around 3-4 weeks old were infected to study the role of IL-4 in respiratory infection and allergy caused by early life Chlamydia infection. We observed that IL-4 is linked with Chlamydia respiratory infection and its absence lowers respiratory infection. IL-4R α2 is also responsible for controlling the IL-4 signaling pathway and averts the progression of infection and inflammation. Furthermore, the IL-4 signaling pathway also influences infection-induced AHR and aids in increasing AAD severity. STAT6 also promotes respiratory infection caused by Ch. pneumoniae and further enhanced its downstream process. Our study concluded that IL-4 is a potential target for preventing infection-induced AHR and severe asthma.