• 분석과학
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• 제22권6호
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• pp.498-503
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• 2009

폐암은 전 세계적으로 높은 사망률 때문에 죽음에 이르게 되는 암이다. 폐암은 소세포암과 비소 세포암 두 종류로 나누어 지는데 비소세포암 환자에게서 EGFR 돌연변이가 발견되었고 이 EGFR 돌연변이는 방사선치료와 EGFR tyrosin kinase의 저해제인 gefitinib과 erlotinib의 반응에도 연관되어진다. 이와 같이 EGFR 돌연변이의 검출은 효과적인 치료방법을 제시해 줄 수 있을 것이다. 본 연구에서는 간단하고 값이 싸며, 반응시간이 더 빠르게 유전자 다형성을 검출 할 수 있는 칩-기반 등온증폭반응을 수행하였다. 그 결과, 이 등온증폭 방법은 빠른 증폭 시간과 높은 민감성, 특이성을 가지고 있었으며 현증 검증에서 EGFR 돌연변이를 빠르고 정확하게 진단할 수 있는 유용한 방법이 될 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.255-260
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• 2012

Patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor (EGFR) mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors ((EGFR-TKIs)-namely gefitinib and erlotinib. However, these patients eventually develop resistance to EGFR-TKIs. Despite the fact that this acquired resistance may be the result of a secondary mutation in the EGFR gene, such as T790M or amplification of the MET proto-oncogene, there are other mechanisms which need to be explored. MicroRNAs (miRs) are a class of small non-coding RNAs that play pivotal roles in tumorigenesis, tumor progression and chemo-resistance. In this study, we firstly successfully established a gefitinib resistant cell line-HCC827/GR, by exposing normal HCC827 cells (an NSCLC cell line with a 746E-750A in-frame deletion of EGFR gene) to increasing concentrations of gefitinib. Then, we found that miR-214 was significantly up-regulated in HCC827/GR. We also showed that miR-214 and PTEN were inversely expressed in HCC827/GR. Knockdown of miR-214 altered the expression of PTEN and p-AKT and re-sensitized HCC827/GR to gefitinib. Taken together, miR-214 may regulate the acquired resistance to gefitinib in HCC827 via PTEN/AKT signaling pathway. Suppression of miR-214 may thus reverse the acquired resistance to EGFR-TKIs therapy.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4623-4627
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• 2014

Background: The epidermal growth factor receptor (EGFR) plays a vital role in the activation and inactivation of receptor tyrosine kinases. Mutations in exons 19 and 21 of EGFR are commonly found to be associated with non small cell lung carcinoma and triple negative breast cancer, enhancing sensitivity to EGFR targeting chemotherapeutic agents. Since amplification and prolonged activation of EGFR molecules have been identified in oral squamous cell carcinomas (OSCC), we investigated whether OSCCs carried mutations in exons 19 and 21 of EGFR to their incidence. Materials and Methods: Tumor chromosomal DNA isolated from forty surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking exons 19 and 21 of the EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Data analysis of the EGFR exon 19 and 21 coding sequences did not show any mutations in the forty OSCC samples that were analyzed. Conclusions: To the best of our knowledge, this is the first study to have investigated the genetic status of exons 19 and 21 of EGFR in Indian OSCCs and identified that mutation in EGFR exon 19 and 21 may not contribute towards their genesis. The absence of mutations also indicates that oral cancerous lesions may not be as sensitive as other cancers to chemotherapeutic agents targeting EGFR.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.131-136
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• 1994

In the present study, in order to make an in vitro model of gastric mucosa for physiological and pharmacological studies, we established two immortalized gastric surface mucous cell lines (GSM06 and GSM10), which produce periodic acid-Schiff (PAS)-and concanavalin A (Con A)-positive glycoproteins, from a primary culture of gastric fundic mucosal cells of adult transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene 〔1]. Gastric fundic mucosal cells were isolated as a modification of a previously described method for rats by Schepp et al. (2). The isolated gastric fundic mucosal cells were cultured in DME/F12 medium supplemented with 2% fetal bovine serum (FBS), 1% ITES (consisting of 2 mg/1 insulin, 2 mgg/1 transferrin, 0.122 mg/1 ethanolamine and 0.00914 mg/1 sodium selenite) and 10 ng/ml recombinant epidermal growth factor (EGF) in a collagen-coated culture dish. To remove fibroblastic cells from the culture, gastric mucosal cells were incubated in the culture medium containing dispase (25 U/ml) for 24 h. The cells, uncontaminated with fibroblastic cells, were then cloned by colony formation. In our series of three attempts, two cell lines (GSM06 and GSM10) have been established at last. The cells proliferated, attached to the dish ana grew until confluent monolayers were formed, and maintained tight contact with neighboring cells. Both GSM06 and GSM10 cells have now been in culture for more than 9 months with regular passaging. The either cell produced

• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.20-33
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• 2017

Objective: Superstimulatory treatment of one-month-old lambs can achieve synchronous development of numerous growing follicles. However, these growing follicles cannot complete maturation and ovulation. Oocyte maturation and competence are acquired during follicular development, in which granulosa cells play an essential role. Methods: In this study, we applied RNA sequencing to analyze and compare gene expression between prepubertal and adult superstimulated follicle granulosa cells in sheep. Results: There were more than 300 genes that significantly differed in expression. Among these differently expressed genes, many extracellular matrix genes (EGF containing Fibulin Like Extracellular Matrix Protein 1, pentraxin 3, adrenomedullin, and osteopontin) were significantly down-regulated in the superstimulated follicles. Ingenuity pathway and gene ontology analyses revealed that processes of axonal guidance, cell proliferation and DNA replication were expressed at higher levels in the prepubertal follicles. Epidermal growth factor, T-Box protein 2 and beta-estradiol upstream regulator were predicted to be active in prepubertal follicles. By comparison, tumor protein P53 and let-7 were most active in adult follicles. Conclusion: These results may contribute to a better understanding of the mechanisms governing the development of granulosa cells in the growing follicle in prepubertal sheep.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3843-3849
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• 2013

이배체 단위발생 돼지 난자를 체외 배양시 배반포 형성 단계에서 FBS (우태아 혈청), BSA (우혈청 알부민), EGF(상피세포 성장인자)를 배양액에 첨가하였을 때 이배체 단위발생 에서 총세포수, 세포사멸 및 세포사멸에 관여하는 유전자의 발현 효과를 조사하고자 본 연구를 수행하였다. 0.4% BSA를 배양액에 첨가 하였을 때 2 세포기 단계 단위발생의 발달은 배반포 까지는 강화 되었다 (p<0.01). FBS 처리 시는 배반포의 세포 수는 감소시켰으나 세포 사멸률은 증가하였다(p<0.01). 하지만 EGF가 존재할 때 BSA 처리는 총 세포수를 증가 시켰다. RT-PCR의 결과에 의하면 EGF는 0.4% BSA가 존재하는 배양액에서는 Bcl-xL mRNA 발현을 증가시키고 BSA와 EGF 가 단독으로 존재 할 때는 효과가 없었다. 하지만 FBS 처리시 Bcl-xL 유전자 발현은 감소하고 Bak 유전자의 발현은 증가시킨다. 이러한 결과 세포사멸에 관여하는 유전자의 발현은 배양액의 첨가물에 따라 유의적으로 영향을 받으며, 돼지 배아의 체외 배양시 세포사멸과 초기발달에 관여함을 시사한다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.4019-4023
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• 2016

Background: Colorectal cancer (CRC) or bowel cancer is one of the most important cancer diseases, needing serious attention. The cell surface receptor gene human epidermal growth factor receptor (EGFR) may have an important role in provoking CRC. In this pharmaceutical era, it is always attempted to identify plant-based drugs for cancer, which will have less side effects for human body, unlike the chemically synthesized marketed drugs having serious side effects. So, in this study the authors tried to assess the activity of two important plant compounds, ferulic acid (FA) and p-coumaric acid (pCA), on CRC. Materials and Methods: FA and pCA were tested for their cytotoxic effects on the human CRC cell line HCT 15 and also checked for the level of gene expression of EGFR by real time PCR analysis. Positive results were confirmed by in silico molecular docking studies using Discovery Studio (DS) 4.0. The drug parallel features of the same compounds were also assessed in silico. Results: Cytotoxicity experiments revealed that both the compounds were efficient in killing CRC cells on a controlled concentration basis. In addition, EGFR expression was down-regulated in the presence of the compounds. Docking studies unveiled that both the compounds were able to inhibit EGFR at its active site. Pharmacokinetic analysis of these compounds opened up their drug like behaviour. Conclusions: The findings of this study emphasize the importance of plant compounds for targeting diseases like CRC.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4113-4117
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• 2012

Breast cancer is a prevalent heterogeneous malignant disease. Gene expression profiling by DNA microarray can classify breast tumors into five different molecular subtypes: luminal A, luminal B, HER-2, basal and normal-like which have differing prognosis. Recently it has been shown that immunohistochemistry (IHC) markers including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2), can divide tumors to main subtypes: luminal A (ER+; PR+/-; HER-2-), luminal B (ER+;PR+/-; HER-2+), basal-like (ER-;PR-;HER2-) and Her2+ (ER-; PR-; HER-2+). Some subtypes such as basal-like subtype have been characterized by poor prognosis and reduced overall survival. Due to the importance of the ER signaling pathway in mammary cell proliferation; it appears that epigenetic changes in the $ER{\alpha}$ gene as a central component of this pathway, may contribute to prognostic prediction. Thus this study aimed to clarify the correlation of different IHC-based subtypes of breast tumors with $ER{\alpha}$ methylation in Iranian breast cancer patients. For this purpose one hundred fresh breast tumors obtained by surgical resection underwent DNA extraction for assessment of their ER methylation status by methylation specific PCR (MSP). These tumors were classified into main subtypes according to IHC markers and data were collected on pathological features of the patients. $ER{\alpha}$ methylation was found in 25 of 28 (89.3%) basal tumors, 21 of 24 (87.5%) Her2+ tumors, 18 of 34 (52.9%) luminal A tumors and 7 of 14 (50%) luminal B tumors. A strong correlation was found between $ER{\alpha}$ methylation and poor prognosis tumor subtypes (basal and Her2+) in patients (P<0.001). Our findings show that $ER{\alpha}$ methylation is correlated with poor prognosis subtypes of breast tumors in Iranian patients and may play an important role in pathogenesis of the more aggressive breast tumors.

• Molecules and Cells
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• 제44권3호
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• pp.168-178
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• 2021

The retinal pigment epithelium (RPE) forms a monolayer sheet separating the retina and choroid in vertebrate eyes. The polarized nature of RPE is maintained by distributing membrane proteins differentially along apico-basal axis. We found the distributions of these proteins differ in embryonic, post-natal, and mature mouse RPE, suggesting developmental regulation of protein trafficking. Thus, we deleted tumor susceptibility gene 101 (Tsg101), a key component of endosomal sorting complexes required for transport (ESCRT), in embryonic and mature RPE to determine whether ESCRT-mediated endocytic protein trafficking correlated with the establishment and maintenance of RPE polarity. Loss of Tsg101 severely disturbed the polarity of RPE, which forms irregular aggregates exhibiting non-polarized distribution of cell adhesion proteins and activation of epidermal growth factor receptor signaling. These findings suggest that ESCRT-mediated protein trafficking is essential for the development and maintenance of RPE cell polarity.

• International Journal of Oral Biology
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• 제46권4호
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• pp.176-183
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• 2021

Oral squamous cell carcinoma (OSCC) metastasis is characterized by distant metastasis and local recurrence. Combined chemotherapy with cisplatin and 5-fluorouracil is routinely used to treat patients with OSCC, and the combined use of gefitinib with cytotoxic drugs has been reported to enhance the sensitivity of cancer cells in vitro. However, the development of drug resistance because of prolonged chemotherapy is inevitable, leading to a poor prognosis. Therefore, understanding alterations in signaling pathways and gene expression is crucial for overcoming the development of drug resistance. However, the altered characterization of Ca²⁺ signaling in drug-resistant OSCC cells remains unclear. In this study, we investigated alterations in intracellular Ca²⁺ ([Ca²⁺]_i) mobilization upon the development of gefitinib resistance in human tongue squamous carcinoma cell line (HSC)-3 and HSC-4 using ratiometric analysis. This study demonstrated the presence of altered epidermal growth factor- and purinergic agonist-mediated [Ca²⁺]_i mobilization in gefitinib-resistant OSCC cells. Moreover, Ca²⁺ content in the endoplasmic reticulum, store-operated calcium entry, and lysosomal Ca²⁺ release through the transient receptor potential mucolipin 1, were confirmed to be significantly reduced upon the development of apoptosis resistance. Consistent with [Ca²⁺]_i mobilization, we identified modified expression levels of Ca²⁺ signaling-related genes in gefitinib-resistant cells. Taken together, we propose that the regulation of [Ca²⁺]_i mobilization and related gene expression can be a new strategy to overcome drug resistance in patients with cancer.