• Biomolecules & Therapeutics
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• 제31권2호
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• pp.200-209
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• 2023

Patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to the tyrosine kinase inhibitor gefitinib, however, the treatment becomes less effective over time by resistance mechanism including mesenchymal-epithelial transition (MET) overexpression. A therapeutic strategy targeting MET and EGFR may be a means to overcoming resistance to gefitinib. In the present study, we found that picropodophyllotoxin (PPT), derived from the roots of Podophyllum hexandrum, inhibited both EGFR and MET in NSCLC cells. The antitumor efficacy of PPT in gefitinib-resistant NSCLC cells (HCC827GR), was confirmed by suppression of cell proliferation and anchorage-independent colony growth. In the targeting of EGFR and MET, PPT bound with EGFR and MET, ex vivo, and blocked both kinases activity. The binding sites between PPT and EGFR or MET in the computational docking model were predicted at Gly772/Met769 and Arg1086/Tyr1230 of each ATP-binding pocket, respectively. PPT treatment of HCC827GR cells increased the number of annexin V-positive and subG1 cells. PPT also caused G2/M cell-cycle arrest together with related protein regulation. The inhibition of EGFR and MET by PPT treatment led to decreases in the phosphorylation of the downstream-proteins, AKT and ERK. In addition, PPT induced reactive oxygen species (ROS) production and GRP78, CHOP, DR5, and DR4 expression, mitochondrial dysfunction, and regulated involving signal-proteins. Taken together, PPT alleviated gefitinib-resistant NSCLC cell growth and induced apoptosis by reducing EGFR and MET activity. Therefore, our results suggest that PPT can be a promising therapeutic agent for gefitinib-resistant NSCLC.

• 생명과학회지
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• 제19권8호
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• pp.1073-1080
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• 2009

비스테로이드성 항염증약(nonsteroidal anti-inflammatory drugs; NSAIDs)은 항염 및 진통효과를 나타내며, 염증억제 외에 다양한 신호전달 분자를 통해 여러 가지 세포생리활성을 조절하며, 암세포에서는 세포사멸 유도를 통한 항암제 효과를 보이고 있다. 본 연구에서는 NSAIDs가 암세포사멸프로그램을 작동시키는데 있어 phosphatidyl inositol 3-kinase (PI3K)-Akt/protein kinase B (PKB) 그리고 MEK1/2-ERK1/2 신호 전달계과 같은 anti-apoptotic program이 NSAIDs의 효과를 경감시키는 것으로 예상하고, 이들 항세포사멸 프로그램을 억제하였을 경우, NSAIDs의 세포사멸 유도작용이 증가되는지 그 가능성을 조사하였다. 세포사멸은 Hoeschst 33342으로 핵응축과 핵 쪼개짐을 염색하여 확인하였다. Western blotting을 통해 단백질 발현과 역전사중합효소연쇄반응을 통해 mRNA 발현을 확인하였다. NSAIDs 처리와 동시에 PI3K-Akt/PKB와 MEK-ERK1/2 신호전달계의 억제제를 함께 처리했을 때, NSAIDs의 세포사멸유도작용이 증가함을 확인하였다. 또한 PI3K와 MEKl/2 신호전달계의 상위에 존재하는 receptor tyrosine kinases (RTKs)의 억제제인 genistein을 함께 처리하였을 때에도 유사한 효과가 나타남을 확인하였다. 그리고 이들 복합처리에 의해 NAG-1 발현이 증가하며 NAG-1 interference 하였을 경우 복합처리에 의한 세포사멸증진 효과가 사라짐을 확인하였다. 본 연구결과는 암세포에 활성화 되어 있는 세포생존프로그램을 제어하는 물질(genistein 혹은 LY294002+U0126)을 복합처방함으로써 NSAIDs의 항암작용을 증진시킬 수 있음을 보여준다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.186-186
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• 1994

Many agonists have been known to activate the hydrolysis of membrane phospholipids through the bindings with corresponding receptors on the various cells. Diacylglycerol and inositol 1,4,5-trisphosphate(IP3) generated by the action of phosphoinositide-specific phospholipase C (PI-PLC) are well known second messengers for the activation of protein kinase C and the mobilization of Ca2+ in many cells. Three types of PI-PLC isozyme (${\alpha}$,${\gamma}$, and $\delta$) and several subtrpes for each type have been identified from mammalian sources by purification of enzymes and cloning of their cDNAs. Each type PI-PLC isozyme is coupled to different receptors and mediators, for example, ${\beta}$-types are coupled to the seven-transmembrane-receptors via Gq family of G-proteins and ${\beta}$-types directly to the receptor tyrosine kinases. Specific modulators for the signaling pathway through each type of PI-PLC should be very useful as potential potential candidates for lend substances in developing novel drugs. To establish the sensitive and convenient screening systems for searching modulators on PI-PLC mediated signaling, two kinds of approaches have been tried. (1) Establishment of in vitro assay condition for each type of PI-PLC isozyme: Overexpression by using vaccinia virus and purification of each isozyme was carried out for the preparation of large amounts of enaymes. Optimum and sensitive assay condition for the measurements of PI-ELC activities were established. (2) Development of the cell lines in which each type of PI-PLC is permanently overexpressed: A fibroblast cell line (3T3${\gamma}$1-7) in which PI-PLC-${\gamma}$1 was overexpressed by using pZip-neo expression vector was developed and used for the measurement of PDGF-induced IP3 formation. The responses for IP3 formed in 3T3${\gamma}$1-7 cells by the treatment of PDGF is 8 times more sensitive than those in control cells. 3T3${\gamma}$l-7 cell is useful for the screening of the inhibitors on the PDGF-induced cellular responses from large number of samples in a small volume(50 ${\mu}$l) and short time(5-15 min). Using these systems, we screened hundreds of herb-extracts for the inhibition of PDGF-induced IP3 formation and selected several extracts that showed the inhibition as the candidates for isolation and characterization of active substances. The determination of the acting point of selected extracts or fractions in the PDGF signaling pathway has been analyzing.

• The Korean Journal of Physiology and Pharmacology
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• 제12권2호
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• pp.83-87
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• 2008

The fyn-related kinase (FRK) belongs to the tyrosine kinase family of protein kinases. Recent studies have shown that Frk affects pancreatic beta cell number during embryogenesis and promotes beta cell cytotoxic signals in response to streptozotocin. To investigate the genetic association between FRK polymorphisms and the risk of obesity in Korean population, single nucleotide polymorphisms (SNPs) in the FRK gene region were selected and analyzed. The body mass index (BMI) was calculated, and biochemical data (systolic blood pressure, diastolic blood pressure, hemoglobin A1C, triglyceride, total cholesterol, high density lipoprotein, and low density lipoprotein) of blood sample from each subject were also measured. One hundred fifty five healthy control and 204 overweight/obesity subjects were recruited. Genotype frequencies of six SNPs [rs6568920 (+8391G>A), rs3756772 (+56780A>G), rs3798234 (+75687C>T), rs9384970 (+68506G>A), rs1933739 (+72978G>A), and rs9400883 (+75809A>G)] in the FRK gene were determined by Affymetrix Targeted Genotyping Chip data. According to the classification of Korean Society for the Study of Obesity, control (BMI 18 to < 23) and overweight/obesity (BMI$\geq$23) subjects were recruited. For the analysis of genetic data, EM algorithm, SNPStats, Haploview, HapAnalyzer, SNPAnalyzer, and Helixtree programs were used. Multiple logistic regression analysis (codominant, dominant, and recessive models) was performed. Age and gender as covariates were adjusted. For biochemical data, Student's t test was used. The mean value of BMI in the control and overweigh/obesity groups was 21.1${\pm}$1.2 (mean${\pm}$SD) and 25.6${\pm}$2.0, respectively. All biochemical data of the overweight/obesity group were statistically significance, compared with the control group. Among six SNPs, two linkage disequilibrium (LD) blocks were discovered. One block consisted of rs1933739 and rs9400883, and the other comprised rs3756772 and rs3798234. One SNP (rs9384970, +68506G>A) showed an association with overweight/obesity in the codominant model (p=0.03). Interestingly, the AA genotype distribution in the overweight/obesity group (n=7, 3.5%) was higher than those in the control group (n=1, 0.6%), which is not found in either Japanese or Chinese subjects. Therefore, the AA genotype of rs9384970 may be a risk factor for development of obesity in Korean population. The results suggest that FRK may be associated with overweight/obesity in Korean population.

• 생명과학회지
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• 제12권2호
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• pp.164-172
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• 2002

유방암세포는 여러 종류의 성장인자 수용체를 가지며, 이를 통해 성장신호를 전달한다. 따라서, 이러한 수용체들의 신호전달 경로에 있는 공통적인 2차전달자들의 조절기작을 밝히는 것이 중요하다. 이 연구는 MCF-7 cell에 있어서, 에스트로젠과 TGF-$\alpha$ , EGF와 같은 성장인자의 mitogenic signal을 전달하는 second messenger에 폴리아민이 어떤 영향을 미치는지, 또 membrane-associated proteins의 인산화에 폴리아민이 어떤 조절기작을 가지는지를 알아보고자 한다. 폴리아민 생합성 억제제인 DFMO는 154, 134, 116, 104 kDa의 membrane-associated proteins의 인산화를 억제하였고, DFMO에 의해 억제된 단백질 인산화는 폴리아민 첨가로 다시 회복 되었다. $E_2$, TGF-$\alpha$, EGF, DFMO는 모두 단백질의 타이로신 인산화에는 크게 영향을 미치지 않았으나, 처리해준 폴리아민에 의해 154, 134, 116 kDa의 단백질의 타이로신 인산화는 급격히 증가하였다. 또한 $E_2$, TGF-$\alpha$, EGF는 모두 같은 단백질에서 유사하게 인산화를 유도하였다. 이러한 결과로 볼 때, $E_2$와 TGF-$\alpha$, EGF와 같은 성장촉진인자의 signaling pathway는 154, 134, 116, 104 kDa 단백질을 기질로 하는 여러 가지 다양한 종류의 protein kinase를 통해서 서로 cross-talk하고 있으며, 폴리아민은 154, 134, 116, 104 kDa와 같은 여러 가지 membrane-associated proteins의 인산화를 조절함으로서 이러한 cross-talk pathway에 관여하고 있는 것으로 사려된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7367-7369
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• 2013

Background: Inoperable and metastatic hepatocellular carcinoma (HCC) is associated with a poor prognosis and low chemotherapeutic efficiency. Sorafenib is an oral multi-kinase inhibitor exerting its effects via the RAF/MEK/ERK pathway, vascular endothelial growth factor receptor (VEGFR) and platelet derived growth factor receptor beta (PDGFR-${\beta}$) tyrosine kinases. Randomized studies have shown a significant contribution of sorafenib to life expectancy and quality of life of cancer patients. The aim of the present study is to evaluate the efficacy and side effects of sorafenib therapy in Turkey. Materials and Methods: Data for 103 patients (82 males, 21 females) receiving sorafenib therapy in 13 centers from February 2008 to December 2012 were evaluated. Median age was 61 years and median ECOG performance status was 1 (range: 0-2). 60 patients (58%) had hepatitis B, 15 patients (15%) had hepatitis C infection and 12 patients (12%) had a history of alcohol consumption. All of the patients had Child scores meeting the utilization permit of the drug in our country (Child A). Results: A total of 571 cycles of sorafenib therapy were administered with a median of four per patient. Among the evaluable cases, there was partial response in 15 (15%), stable disease in 52 (50%), and progressive disease in 36 (35%). Median progression-free survival was 18 weeks and median overall survival was 48 weeks. The dose was reduced only in 6 patients and discontinued in 2 patients due to grade 3-4 toxicity, 18 patients (17%) suffering hand-foot syndrome, 7 (7%) diarrhea, and 2 (2%) vomiting. Conclusions: This retrospective study demonstrated better efficacy of sorafenib therapy in patients with advanced HCC compared to the literature while progression-free survival and overall survival findings were comparable. The side effect rates indicate that the drug was tolerated well. In conclusion, among the available treatment options, sorafenib is an efficient and tolerable agent in patients with inoperable or metastatic HCC.