• 생명과학회지
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• 제29권6호
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• pp.645-652
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• 2019

전세계적으로 폐암 발병율은 서서히 감소하는 추세이지만, 여전히 암 관련 사망의 주요 원인으로 지목되고 있으며, 이에 따라 폐암 진단과 치료를 위한 새로운 분자적 지표를 발굴하는 연구가 활발히 이루어지고 있다. 본 연구진이 수행한 기존 연구에 따르면 폐암 환자에게서는 전사인자 중 하나인 TFAP2C가 높은 비율로 발현되며, 이 전사인자를 통해 폐암 발달에 상당한 영향을 끼치는 것을 확인할 수 있었다. TFAP2C는 다른 유전자들의 발현을 조절하여 암 형성에 기여하게 된다. 마이크로어레이 분석을 통해 TFAP2C에 의해 발현양이 조절되는 잠재적 표적 유전자들을 확인하였고, 특히 TFAP2C siRNA를 처리하였을 때 발현이 감소되는 원암유전자들 중 CDC20과 TRIB3 유전자를 최종적으로 선별하였다. 리얼타임 qRT-PCR과 웨스턴블롯을 통하여 두 유전자가 TFAP2C에 의존적으로 발현됨을 확인하였으며, 세포 생존 분석법을 통하여 CDC20과 TRIB3의 발현 증가가 폐암세포의 세포 증식을 유의미하게 유도하는 것을 확인하였다. 이와 더불어, CDC20과 TRIB3의 과발현이 폐암세포의 세포사멸 수준을 감소시켜 폐암 형성에 관여함을 확인하였다. 본 연구를 통하여 CDC20과 TRIB3가 폐암 형성을 유도할 수 있는 잠재적인 원암유전자로 기능함을 밝힐 수 있었으며, 두 유전자가 폐암 진단을 위한 표적유전자로서의 역할을 수행할 수 있을 것으로 기대한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권9호
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• pp.3865-3871
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• 2014

It is becoming progressively more understandable that different phytochemicals isolated from edible plants interfere with specific stages of carcinogenesis. Cancer cells have evolved hallmark mechanisms to escape from death. Concordant with this approach, there is a disruption of spatiotemproal behaviour of signaling cascades in cancer cells, which can escape from apoptosis because of downregulation of tumor suppressor genes and over-expression of oncogenes. Genomic instability, intra-tumor heterogeneity, cellular plasticity and metastasizing potential of cancer cells all are related to molecular alterations. Data obtained through in vitro studies has convincingly revealed that curcumin, EGCG, resveratrol and quercetin are promising anticancer agents. Their efficacy has been tested in tumor xenografted mice and considerable experimental findings have stimulated researchers to further improve the bioavailability of these nutraceuticals. We partition this review into different sections with emphasis on how bioavailability of curcumin, EGCG, resveratrol and quercetin has improved using different nanotechnology approaches.

• BMB Reports
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• 제34권1호
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• pp.28-32
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• 2001

The Fos-Jun heterodimers are part of the regulatory network of gene expression and nuclear proteins encoded by proto-oncogenes. The activation of Fos-Jun is important in the transmission of the tumor-promoting signal from the extracellular environment to the nuclear transcription mechanism. To search for the inhibitors of the Fos-Jun DNA complex formation, several natural products were screened and water-soluble paeoniflorin reduced the binding activity of the Fos-Jun heterodimer. This active compound was purified by silica gel column chromatography and HPLC. The electrophoresis mobility shift assay and reverse-phase HPLC test showed that paeoniflorin reduced the AP-l function. The cytotoxic effect of paeoniflorin was observed in HL-60. These results indicate that paeoniflorin blocks the Fos-Jun heterodimer-binding site of the AP-l DNA and it also has cytotoxic effects on human leukemia cell lines.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2575-2580
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• 2015

Cancer is a multifaceted and genomically complex disease and rapidly accumulating high impact research is deepening our understanding related to the mechanisms underlying cancer development, progression and resistance to therapeutics. Increasingly it is being realized that genetic/epigenetic mutations, inactivation of tumor suppressor genes, overexpression of oncogenes, deregulation of intracellular signaling cascades and loss of apoptosis are some of the extensively studied aspects. Confluence of information suggested that rapidly developing resistance to therapeutics is adding another layer of complexity and overwhelmingly increasing preclinical studies are identifying different natural agents with efficacy and minimal off-target effects. We partition this multi-component review into citrus fruits and their bioactive ingredients mediating rebalancing of pro- and anti-apoptotic proteins to induce apoptosis in resistant cancer cells. We also discuss how oncogenic protein networks are targeted in cancer cells and how these findings may be verified in preclinical studies.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.17-24
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• 2014

Gastric cancer is highly invasive, aggressively malignant, and amongst the most prevalent of all forms of cancer. Despite improved management strategies, early stage diagnosis of gastric cancer and accurate prognostic assessment is still lacking. Several recent reports have indicated that the pathogenesis of gastric cancer involves complex molecular mechanisms and multiple genetic and epigenetic alterations in oncogenes and tumor suppressor genes. Functional inactivation of the tumor suppressor protein PTEN (Phosphatase and Tensin Homolog) has been detected in multiple cases of gastric cancer, and already shown to be closely linked to the development, progression and prognosis of the disease. Inactivation of PTEN can be attributed to gene mutation, loss of heterozygosity, promoter hypermethylation, microRNA- mediated regulation of gene expression, and post-translational phosphorylation. PTEN is also involved in mechanisms regulating tumor resistance to chemotherapy. This review provides a comprehensive analysis of PTEN and its roles in gastric cancer, and emphasizes its potential benefits in early diagnosis and gene therapy-based treatment strategies.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1367-1378
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• 2017

Epigenetic alterations such as DNA methylation, histone acetylation, and chromatin remodeling can control gene expression by regulating gene transcription. DNA methylation is one of the frequent epigenetic events that play important roles in cancer development. Cancer cells can gain significant resistance to anticancer drugs and escape programmed cell death through major epigenetic changes, including DNA methylation. To date, several research groups have identified instances of both (i) hypermethylation of tumor suppressor genes, and (ii) global hypomethylation of oncogenes. These changes in DNA methylation status could be used as biomarkers for the diagnosis and prognosis of cancer patients undergoing chemotherapies or other clinical therapies. Herein, we describe genes for which methylation is dependent upon anticancer drug resistance in patients with gastric cancer; we then suggest a significant epigenetic target to focus on for overcoming anticancer drug resistance.

• 한국식품영양과학회지
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• 제21권3호
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• pp.314-318
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• 1992

비파엽에서 분리동정한 활성성분인 울솔레산을 sarcoma 180 cells에 처리하여 c-myc과 c-Ha-ras 암유전자 발현에 있어서 변화를 조사하였다. 그 결과 c-myc 유전자의 발현에서는 뚜렸한 감소가 관찰되었으나 c-Ha-ras 유전자 발현은 대조군과 거의 차이가 없었다. Cell proliferation에 중요한 역할을 하는 것으로 추측되고 있는 c-myc 유전자 발현의 감소는 지금까지 보고된 그 물질의 antipromotional effect와 관계있는 것으로 보여진다.

• Molecules and Cells
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• 제39권8호
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• pp.619-624
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• 2016

Glioblastoma stem cells (GBM-SCs) are believed to be a subpopulation within all glioblastoma (GBM) cells that are in large part responsible for tumor growth and the high grade of therapeutic resistance that is so characteristic of GBM. MicroRNAs (miR) have been implicated in regulating the expression of oncogenes and tumor suppressor genes in cancer stem cells, including GBM-SCs, and they are a potential target for cancer therapy. In the current study, miR-203 expression was reduced in $CD133^+$ GBM-SCs derived from six human GBM biopsies. MicroRNA-203 transfected GBM-SCs had reduced capacity for self-renewal in the cell sphere assay and increased expression of glial and neuronal differentiation markers. In addition, a reduced proliferation rate and an increased rate of apoptosis were observed. Therefore, miR-203 has the potential to reduce features of stemness, specifically in GBM-SCs, and is a logical target for GBM gene therapy.

• Natural Product Sciences
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• 제25권4호
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• pp.298-303
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• 2019

This study investigated the cytotoxic effects and mechanism of action of asiatic acid in pancreatic cancer cell lines. First, we confirmed the cell viability of MIA PaCa-2 and PANC-1 cells after asiatic acid administration for 48 and 72 h. The viability of MIA PaCa-2 and PANC-1 cells decreased in a dose-dependent manner following asiatic acid administration. To investigate the underlying mechanism, we performed a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, annexin V assay, and western blotting. Asiatic acid induced apoptosis and autophagy through activation of AMP-activated protein kinase (AMPK) and inhibition of mammalian target of rapamycin (mTOR) in MIA PaCa-2 cells. Finally, the expression of miR-17 and miR-21, known as oncogenes in pancreatic cancer, was decreased by asiatic acid. These results indicate that asiatic acid has potential as a new therapeutic agent against pancreatic cancer.

• BMB Reports
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• 제29권5호
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• pp.442-447
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• 1996

Mutations in codon 12, 13 and 61 of one of the three ras genes, H-ras, K-ras and N-ras, convert these genes into active oncogenes. The presence of H-ras gene mutations have important prognostic implications in various cancers. In this study, the H-ras gene mutations were investigated by two-step PCRRFLP in patients with bladder and stomach cancer. For the control experiments, T24 and SK2 cell lines were used. In a total of 36 bladder cancer patient cases, five (13.9%) mutations were found by this method. Of these, point 12 mutations were two (5.6%) cases and point 61 mutations were three (8.3%) cases. On the other hand, H-ras mutation was not found in 29 cases of stomach cancer. The results of the mutated H-ras gene confirmed by direct sequencing analysis were correlated well with PCR analysis. From the sensitivity test, the H-ras mutation was found to have about 0.2% of mutated DNA mingled in normal DNA. In conclusion, the H-ras mutation has a higher clinical Significance in bladder cancer than stomach cancer. Moreover the two-step PCR-RFLP method is sensitive, rapid and relatively simple for clinical work in detecting H-ras point mutations.