• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1827-1831
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• 2009

Ligand molecules that can recognize and interact with cancer cell surface marker proteins with high affinity and specificity should greatly aid the development of novel cancer diagnostics and therapeutics. HER-2/ErbB2/Neu (HER-2), a member of the epidermal growth factor receptor family, is specifically overexpressed on the surface of breast cancer cells and serves as both a useful biomarker and a therapeutic target for breast cancer. In this study, we aimed to isolate RNA aptamers that specifically bind to a HER-2-overexpressing human breast cancer cell line, SK-BR-3, using Cell-SELEX strategy. The selected aptamers showed strong affinity to SK-BR-3, but not to MDAMB- 231, a HER-2-underexpressing breast cancer cell line. In addition, we confirmed the specific targeting of HER-2 receptor by aptamers using an unrelated mouse cell line overexpressing human HER-2 receptor. The HER-2-targeting RNA aptamers could become a useful reagent for the development of breast cancer diagnostics and therapeutics.

• Radiation Oncology Journal
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• 제22권2호
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• pp.77-90
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• 2004

종양 발생 과정에 관여되고 있는 분자 생물학적 기전을 직접 공격해 보자고 하는 치료 방침은 암 치료에 있어서 아주 유망한 치료방법의 하나로 인정되고 있다. Epidermal growth factor receptor (EGFR) 수용체에 여러 ligands가 결합하게 되면 발암 단계에서부터 암의 진행 과정과 전이 과정 그리고 방사선에 대한 저항성과 관련된 여러 가지중요한 신호전달체계를 활성화시킨다. 특히 진행된 두경부 암 환자들에서 EGFR이 과발현 된 경우에는 매우 불량한 예후를 나타내고 있기 때문에 이러한 signaling pathway의 selective targeting을 위한 많은 임상 시도가 이루어지고 있다. 현재까지 알려진 표적치료 항암제로는 크게 EGFR에 대한 monoclonal antibody와 tyrosin kinase Inhibitors로 대별될 수 있는데 이와 같은 약제들은 여러 xenograft에서 고무적인 실험 결과들이 입증되어 곧 바로 임상 현장에서 적용되고 있다. 그러나 기대와는 달리 EGFR Inhibitor 단독으로 치료한 초기 임상연구 결과들을 보면 극히 소수의 환자에서만 미미한 효과를 나타내고 있고, 방사선 치료와의 병용치료에서도 괄목할만한 항암 효과를 보여주지 않고 있다. 그럼에도 불구하고 많은 실험적 데이터로부터 여러 가지 생물학적 이점이 밝혀져 있고 또 미래 지향적인 치료법의 하나로 각광을 받고 있기 때문에 현재 많은 연구자들은 어떤 환자 군에서 이러한 표적 치료가 도움이 될 것이며, 방사선 치료 또는 항암 치료와는 어떤 방식으로 조합할 것인지, 또 그 순서는 어떻게 할 것이며, 또 환자 선정에 있어 reliable marker는 무엇인지, 어떻게 체내에서 신호 전달체계의 효과적인 차단을 확인할 수 있겠는지, 또한 multiple targ리ed therapy가 필 요하도록 하는 targeted agent에 대 한 Intrinsic 또는 acquired resistance의 기전은 무엇인지 등등, 현재 당면하고 있는 많은 문제점을 규명하고자 노력하고 있다. 특히 EGFR-signaling pathway를 표적으로 하는 표적 지향적 방사선 치료를 위한 translation research의 적절한 모델이 되고 있는 두경부 암 환자에서 이러한 제반 문제점을 해결하기 위해서는 더 많은 임상 연구와 함께 well-Integrated laboratory clinical research program이 필요할 것으로 생각된다 또한 EGFR antagonist 외에도 anglogenlc pathway나 cell-cycle pathway를 표적으로 하는 새로운 약제들이 계속 개발되고 있고 이에 관한 연구가 활발히 진행 중이다. 따라서 이 고찰에서는 두경부 암 환자에서 이러한 약제들을 방사선 치료와 병용하였을 때의 임상 연구 결과들을 재검토해 보고 부가적으로 EGFR blockade에 따르는 내성 문제 그리고 방사선 치료를 병용하면서 여러 표적을 동시에 차단시키는 multiple-targeted therapy의 개발 현황을 간략히 소개하고자 한다

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 추계학술발표회초록집
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• pp.54-54
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• 2003

DLC films were deposited on Si(100) substrates by inductively coupled plasma (ICP) assisted chemical vapor deposition (CVD). A mixture of acetylene (C$_2$H$_2$) and argon (Ar) gases was used as the precursor and plasma source, respectively. The structure of the films was characterized by the Raman spectroscopy. Results from the Raman spectroscopy analysis indicated that the property change of the DLC films is due to the sp$^3$ and sp$^2$ ratio in the films under various conditions such as ICP power, working pressure and RF substrate bias. The hydrogen content in the DLC films was determined by an electron recoil detector (ERB). The roughness of the films was measured by atomic force microscope (Am). A microhardness tester was used for the hardness and elastic modulus measurement. The DLC film showed a maximum hardness of 37㎬. In this work, the relationship between deposition parameters and mechanical properties were discussed.

• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.3911-3916
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• 2016

Background: Triple negative (TN) and triple positive (TP) breast cancers both are aggressive types but TN generally has a shorter survival. Objectives: To compare the clinical characteristics and treatment outcomes for patients with TN versus TP breast cancer and to assess various prognostic factors affecting overall survival. Materials and Methods: A retrospective audit of 85 breast cancer patients was conducted in the Department of Radiation Oncology and Medical Oncology on patients from 2006 to 2013 for whom IHC for ER, PgR and Her-2 neu were available. The patients were stratified into: ER-, PR- and Her-2 neu- (Arm A, n=47) and ER+, PgR+ and Her-2 neu+ (Arm B, n=38). Results: TN subtype had higher numbers of premenopausal and advanced stage patients as compared to TP subtype. The locoregional recurrence (LRR) and distant metastatic rate was also higher in TN subtype but there was no definite pattern in both the arms. Among the prognostic factors, patients with premenopausal status and advanced stage in TN breast cancer had inferior survival (P=0.07) whereas for those with postmenopausal status and early stage there was no survival difference between the two arms. Conclusions: TN subtype tends to be more aggressive in terms of younger age and advanced stage at presentation, higher tumour grade, LRR and metastasis, suggesting need for future research efforts on providing aggressive treatment to these patients. We could attribute better outcome for TP subtype to receptor positivity enabling role of hormonal treatment and targeted therapy, although less number of patients received targeted therapy.

• 센서학회지
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• 제28권6호
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• pp.355-359
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• 2019

Exosomes, known as nanoscale extracellular vesicles in the range of 30-150 nm, are known to contain clinically significant information. However, there is still insufficient information on exosomal membrane proteins for cancer diagnosis. In this work, we investigated the characteristics of the membrane proteins of exosomes shed by cultured breast cancer cell lines using a surface plasmon resonance (SPR) spectroscopy and pre-activated alkanethiols modified sensor chips. The antibodies of breast cancer biomarkers such as MCU-16, EpCAM, CD24, ErbB2, and CA19-9 were immobilized on the pre-activated alkanethiols surfaces without any activation steps. The purified exosomes were loaded onto each antibody surface. The affinity rank of the antibody surfaces was decided by the relative capture efficiency factors for the exosomes. In addition, an antibody with a relative capture efficiency close to 100% was tested with exosome concentration levels of 10⁴/µl, 10⁵/µl, and 10⁶/µl for quantitative analysis.

• 대한한의학방제학회지
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• 제31권1호
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• pp.41-51
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• 2023

Objectives : Raphani Semen (Raphanus sativus L.) is known for the various beneficial effects in Korean medicine. This study aimed to investigate the effect of Raphani Semen extract (RSE) against arachidonic acid (AA)+iron-induced oxidative stress in cells. Methods : Ingredients, their target information, oxidative stress liver injury-related proteins was obtained from various network pharmacology databases and software. A hypergeometric test and enrichment analysis were conducted to evaluate associations between protein targets of RSE. The cell viability was assessed by MTT assay, and immunoblot analysis was used to confirm the molecular mechanisms. Results : A compound-target network of RSE was constructed, which consisted of 336 edges between 18 ingredients and 123 protein targets. PI3K-Akt signaling pathway, ErbB signaling pathway, HIF-1 signaling pathway, PPAR signaling pathway, and AMPK signaling pathway was significantly associated with protein targets of RSE. RSE protected HepG2 cells against AA+iron-induced oxidative stress as mediated with AMPK signaling. Conclusion : RSE was found to protect the cells against oxidative stress via the AMPK signaling pathway.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2287-2290
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• 2014

Background: In the past few years, a considerable number of preclinical studies have been proposed metformin as a potential anticancer agent, but some of these studies suffer from a number of methodological limitations such as assessment of cytotoxicity in the presence of supraphysiological glucose concentrations or applying suprapharmacological levels of the drug. These objections have limited the translation of published preclinical data to the clinical setting. The present study aimed to investigate direct anticancer effects of metformin on different molecular subtypes of breast cancer with pharmacological concentrations and under normoglycemic conditions in vitro. Materials and Methods: Breast cancer cell lines from luminal A, luminal B, ErbB2 and triple-negative molecular subtypes were treated with a pharmacological concentration of metformin (2mM) at a glucose concentration of 5.5mM. Time-dependant cell viability was assessed by dye exclusion assay. MTTbased cytotoxicity assays were also performed with metformin alone or in combination with paclitaxel. Results: Metformin did not show any growth inhibitory effects or time-dependant cytotoxicity on breast cancer cell lines in the presence of normal glucose concentrations at the therapeutic plasma level. No augmentation of the antineoplastic properties of paclitaxel was apparent under the tested conditions. Conclusions: Metformin is probably unable to exert cytotoxic or cytostatic effects on breast cancer subtypes at pharmacological concentrations and normal plasma glucose levels. These results highlight the importance of establishing a higher steady-state plasma concentration of metformin in the clinical setting for assessment of anticancer effects in normoglycemic patients.

• Journal of Endocrine Surgery
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• 제18권4호
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• pp.228-235
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• 2018

Purpose: The epidermal growth factor receptor (EGFR) family plays a crucial role in the growth of malignant tumors. EGFR and human EGFR 2 (HER2) protein overexpression are associated with an unfavorable prognosis and are important therapeutic targets in breast cancer. The aim of this study was to evaluate the relationship between EGFR and HER2 expression and clinicopathological factors in papillary thyroid carcinoma (PTC) at a single institution. Methods: A total of 129 consecutive patients with PTC were enrolled in this study and underwent thyroid surgery between October 2013 and February 2015. EGFR and HER2 protein expression was evaluated in the 129 primary tumors by immunohistochemistry, and the results were compared with the clinicopathological features. Results: Of the 129 PTC tumors, 20 (15.5%) were HER2 positive, and 109 (84.5%) were HER2 negative. Moreover, EGFR positivity were observed in 111 (86%) tumors. The mean age of the patients was $46.3{\pm}11.9years$ (range, 20-74 years), and the mean tumor size was $1.08{\pm}0.75cm$ (range, 0.2-3.5 cm). Tumor size, extrathyroidal extension, histological subtype, and TNM stage were not significantly associated with EGFR or HER2 expression. Meanwhile, high Ki-67 labeling index was significantly associated with EGFR expression (P=0.002), HER2 expression was significantly associated with younger age (${\leq}45years$) and cervical lymph node metastasis. Conclusion: Based on our data, it is not clear whether EGFR and HER2 expression is associated with tumor aggressiveness in PTC.

• BMB Reports
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• 제47권5호
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• pp.268-273
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• 2014

HER2-overexpressing breast cancers are characterized by frequent distant metastasis and often develop resistance after short-term effective treatment with the monoclonal antibody drug, trastuzumab. Here, we found that the oncogenic miRNA, miR-221, inhibited apoptosis, induced trastuzumab resistance and promoted metastasis of HER2-positive breast cancers. The tumor suppressor PTEN was identified as a miR-221 target; overexpression of PTEN abrogated the aforementioned miR-221-induced malignant phenotypes of the cells. These findings indicate that miR-221 may promote trastuzumab resistance and metastasis of HER2-positive breast cancers by targeting PTEN, suggesting its role as a potential biomarker for progression and poor prognosis, and as a novel target for trastuzumab-combined treatment of breast cancers.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.3857-3862
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• 2012

A total of 96 cases of invasive breast ductal carcinoma were examined for immunohistochemical expression of Bax and Bcl-2 in the epithelial tumor cells and endothelial cells of the blood vessels. We also investigated the association between both proteins in the epithelium in relation to tumor characteristics such as tumor size, grade, lymph node involvement, microvessel density (MVD), hormonal receptors expression and c-erbB-2 overexpression. Bax expression showed a significant association between tumor and endothelial cells (p<0.001) while Bcl-2 expression in tumor cells was inversely associated with that in the endothelial cells (p<0.001). Expression of Bcl-2 in tumor cells was strongly associated with expression of estrogen and progesterone receptors (p=0.003 and p=0.004, respectively). In addition, intratumoral MVD was significantly higher than peritumoral MVD (p<0.001) but not associated with Bax or Bcl-2 expression and other tumor characteristics. We concluded that the number of endothelial cells undergoing apoptosis was in direct linkage with the number of apoptotic tumor cells. Anti-apoptotic activity of the surviving tumor cells appears to propagate cancer progression and this was influenced by the hormonal status of the cells. Tumor angiogenesis was especially promoted in the intratumoral region and angiogenesis was independent of anti-apoptotic activity.