• Radiation Oncology Journal
• /
• 제19권2호
• /
• pp.171-180
• /
• 2001

목적 : Tissue inhibitor of matrix metalloproteinase (TIMP)는 matrix metalloproteinase (MMP)에 작용하여 암세포의 침윤과 전이를 억제하고 염증, angiogenesis, fibrosis에 중요한 역할을 한다. TIMP 유전자는 여러 cytokine 및 signal molecule에 의하여 조절되는 유전자이므로 방사선에 의한 TIMP의 발현을 측정하고 전사 조절 기전을 연구하고자 하였다. 대상 및 방법 : 두경부암 환자의 병변에서 유도하여 확립한 두경부암 세포주를 이용하여 방사선에 의한 TIMP 유전자 발현을 측정하였다. 각 세포주의 방사선 민감도를 측정하고 transwell을 이용한 invasion assay로 전이성을 측정하였다. TIMP1, TIMP2 발현은 conditioned medium을 취해 ELISA assay로 측정하였다. 방사선조사는 2 Gy, 10 Gy 군으로 나누어 관찰했고 조사 후 시간 간격은 24, 48시간이었다. MTT assay로 생존세포 수를 측정하여 방사선 세포치사로 인한 발현 변화를 보정하였다. hTIMP1 promoter region을 PCR하여 pGL2-basic luciferase reporter vector에 cloning하여 인간 두경부암 세포주에 이입하여 functional TIMP1 발현이 증가하는지 확인하였고 protein kinase C (PKC) activator인 PMA (phorbol 12-myristate 13-acetate)와 Ras에 의한 TIMP1 발현이 유도되는지 확인하였다. 결과 : HN-1, HN-2, HN-3, HN-5, HN골 세포주의 $D_0$는 각각 1.55 Gy, 1.8 Gy, 1.5 Gy, 1.55 Gy, 2.45 Gy 이었다. 각 세포주의 방사선조사 후 MTT assay에 의한 cell viability는 24, 48시간에서 2 Gy인 경우 모두 $94\%$ 이상 그리고 10 Gy에서는 $73\%$ 이상의 생존 세포를 확인하였다. TIMP1, TIMP2 단백의 basal 농도는 24시간 48시간에서 점점 증가하여 세포에서 계속 합성되어 분비되고 있음을 확인하였다. 2 Gy 조사 후 24시간에서 TIMP2는 HN-1, HN-9 세포주에서 감소하였으나, 10 Gy 조사 후에는 두 세포주에서 모두 증가하여 방사선량에 따라 반응이 달랐고, 방사선조사 후 48시간에는 HN-9 세포주에서는 증가하나 HN-9 세포주에서는 감소하여 세포주에 따라 반응이 달랐다. 그러나 방사선에 의한 TIMP1 발현 변화는 미미하였다. TIMP1 reporter gene을 인간 두경부암 세포주에 transfection하고 PMA (100 ng/ml)을 가한 경우 HN-1세포주에서는 유의하게 증가하고 HN-9 세포주에서는 감소하였다. Ras 발현 벡터와 co-transfection한 경우 TIMP1 promoter가 활성화 되었다. 결론 : 모두 두경부 암에서 유래된 세포주 이지만 방사선에 의한 TIMP의 발현 및 전사조절 기전은 세포주 마다 차이가 있었고 이온화 방사선의 용량에 따라서, 방사선조사 후의 시간 경과에 따라서도 TIMP 발현에 차이가 있었다. 이 결과는 TIMP의 전사 및 발현이 여러 종류의 signal molecule에 의하여 영향을 받고, 이 signal molecule들이 각 세포주 마다 다르기 때문으로 사료된다.

• Journal of Acupuncture Research
• /
• 제18권4호
• /
• pp.101-115
• /
• 2001

Objective : To characterize the antitumorigenic potential of Apamin, one of the major components of bee venom, its effects on cell proliferation and the mitogen-activated protein kinase (MAPK) signal transduction pathway were characterized using the human melanoma cell line SK-MEL-2. Methods & Results : Cell counting analysis for cell death demonstrated that consistent with a previous results, SK-MEL-2 cells treated with $0.5-2.0{\mu}g/ml$ of Apamin showed no recognizable cytotoxic effect whereas detectable induction of cell death was identified at concentrations over $5.0{\mu}g/ml$. [3H]thymidine incorporation assay for cell proliferation demonstrated that DNA replication of SK-MEL-2 cells is inhibited by Apamin in a dose- and time-dependent manner. To explore whether Apamin-induced growth suppression is associated with the MAPK signaling pathway, phosphorylation of Erk, a function mediator of MAPK growth-stimulating signal, was examined Western blot assay using a phospho-specific Erkl/2 antibody. A significant increase of Erkl/2 phosphorylation level was observed in Apamin-treated cells compared with untreated control cells. Qantitative RT-PCR analysis revealed that Apamin inhibit expression of MAPK downstream genes such as c-Jun, c-Fos, and cyclin D1 but not expression of MAPK pathway component genes including Ha-Ras, c-Raf-1, MEK1, and Erk. Conclusion : It is strongly suggested that the antitumorigenic activity of Apamin might result in part from its inhibitory effect on the MAPK signaling pathway in human melanoma cells SK-MEL-2.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권6호
• /
• pp.3719-3724
• /
• 2013

Background: RASSF1A has been reported to be a candidate tumor suppressor in non-small cell lung cancer (NSCLC). However, the association between RASSF1A promoter methylation and NSCLC remains unclear, particularly in regarding links to clinicopathologic features. Methods: Eligible studies were identified through searching PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases. Studies were pooled and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated. Funnel plots were also performed to evaluate publication bias. Results: Nineteen studies involving 2,063 cases of NSCLC and 1,184 controls were included in this meta-analysis. A significant association was observed between RASSF1A methylation and NSCLC in the complete data set (OR = 19.42, 95% CI: 14.04-26.85, P < 0.001). Pooling the control tissue subgroups (heterogeneous/autologous) gave pooled ORs of 32.4 (95% CI, 12.4-84.5) and 17.7 (95% CI, 12.5-25.0) respectively. Racial subgroup (Caucasian/Asian) analysis gave pooled ORs of 26.6 (95% CI, 10.9-64.9) and 20.9 (95% CI, 14.4-30.4) respectively. The OR for RASSF1A methylation in poorly-differentiated vs. moderately/well-differentiated NSCLC tissues was 1.88 (95% CI, 1.32-2.68, P<0.001), whereas there were no significant differences in RASSF1A methylation in relation to gender, pathology, TNM stage and smoking behavior among NSCLC cases. Conclusion: This meta-analysis suggests a significant association between RASSF1A methylation and NSCLC, confirming the role of RASSF1A as a tumor suppressor gene. Large-scale and well-designed case-control studies are needed to validate the associations identified in the present meta-analysis.

• BMB Reports
• /
• 제43권7호
• /
• pp.485-490
• /
• 2010

Neurotrophins regulate many aspects of neuronal function through activation of the high affinity Trk receptors. Shc family proteins are implicated in the coupling of RTK to the Ras/mitogen-activated protein kinase signaling cascade. Here we report that the fourth Shc family member, ShcD, associates with TrkB receptor and regulates BDNF-induced MAPK activation. Yeast two-hybrid assay and Co-IP experiments demonstrate ShcD interacts with TrkB in a kinase-activity-dependent manner. Confocal analysis shows ShcD cololizes well with TrkB in transfected 293T cells. Subsequent mapping experiments and mutational analysis indicate that both PTB and SH2 domains are capable of binding to TrkB and PTB domain binds to TrkB NPQY motif. Furthermore, ShcD is involved in BDNF-induced MAPK activation. In summary, we demonstrate that ShcD is a substrate of TrkB and mediates TrkB downstream signaling pathway.

• Radiation Oncology Journal
• /
• 제35권3호
• /
• pp.281-288
• /
• 2017

Purpose: The serum carcinoembryonic antigen (CEA) level has been recognized as a prognostic factor in colorectal cancer, and associated with response of rectal cancer to radiotherapy. This study aimed to identify CEA-interacting proteins in colon cancer cells and observe post-irradiation changes in their expression. Materials and Methods: CEA expression in colon cancer cells was examined by Western blot analysis. Using an anti-CEA antibody or IgG as a negative control, immunoprecipitation was performed in colon cancer cell lysates. CEA and IgG immunoprecipitates were used for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Proteins identified in the CEA immunoprecipitates but not in the IgG immunoprecipitates were selected as CEA-interacting proteins. After radiation treatment, changes in expression of CEA-interacting proteins were monitored by Western blot analysis. Results: CEA expression was higher in SNU-81 cells compared with LoVo cells. The membrane localization of CEA limited the immunoprecipitation results and thus the number of CEA-interacting proteins identified. Only the Ras-related protein Rab-6B and lysozyme C were identified as CEA-interacting proteins in LoVo and SNU-81 cells, respectively. Lysozyme C was detected only in SNU-81, and CEA expression was differently regulated in two cell lines; it was down-regulated in LoVo but up-regulated in SNU-81 in radiation dosage-dependent manner. Conclusion: CEA-mediated radiation response appears to vary, depending on the characteristics of individual cancer cells. The lysozyme C and Rab subfamily proteins may play a role in the link between CEA and tumor response to radiation, although further studies are needed to clarify functional roles of the identified proteins.

• 한국균학회지
• /
• 제44권2호
• /
• pp.103-107
• /
• 2016

본 연구는 국내 주요 식물검역관리 대상 Phytophthora pinifolia를 대상으로 신속하고 정확한 병원균 종동정 및 검출을 위해 Ypt1 유전자 염기서열을 활용하여 제작된 종 특이적 분석용 분자마커와 다양한 PCR 기법을 활용하여 병원균들에 대한 다양한 검출기술의 표준화 및 최적 검출 시스템 구축을 통하여 실제 검역검역 현장에서 활용 가능한 병원균 존재여부의 신속, 정확한 판별기법을 개발하고자 수행하였다. Ypt1 영역의 염기서열을 기초로 선발된 종 특이적 primer는 1~10 pg의 검출민감도를 가지며 193 bp의 종 특이적 PCR 증폭산물을 형성시켰다. 또한 선발된 종 특이적 primer의 종 특이성을 확인하기 위하여 국내 식물검역대상에 포함된 Phytophthora속 종들과 주요 식물병원균들을 대상으로 conventional PCR과 real-time PCR을 수행한 결과 목표로 한 P. pinifolia DNA에서만 특이적 PCR 증폭산물을 확인할 수 있었다. 선발된 종 특이적 primer에 대한 PCR의 검출 민감도를 확인했을 때 conventional PCR의 검출민감도는 1~10 pg이었다.

• 한국한의학연구원논문집
• /
• 제12권3호통권18호
• /
• pp.131-141
• /
• 2006

Hominis Placenta has a broad array of clinical applications in Korean medicine, including treatment of inflammatory conditions such as rheumatoid arthritis. The purpose of this study is to explore the global gene expression profiles in human RAW 264.7 cell lines treated with Hominis Placenta herbal-acupuncture solution (HPHAS) using microarray analysis. The RAW 264.7 cells were treated with lipopolysaccharide (LPS), HPHAS, or both. Of the 8,170 genes profiled in this study, with a cut-off level of two-fold change in the expression, 72 genes (CTD1, regulating synaptic membrane exocytosis 2, etc.) were upregulated and 135 genes(splicing factor, arginine/serine-rich 1, actinin, alpha 1, etc.) downregulated following LPS treatment. One gene (acrosin) was upregulated and 12 genes (phospholipase A2, group IB, neurofilament, heavy polypeptide 200kDa, etc.) were downregulated following HPHAS treatment. Eleven genes (RAB27A, member RAS oncogene family, eosinophil peroxidase, etc.) were upregulated and 16 genes (V-maf musculoaponeurotic fibrosarcoma oncogene homolog G (avian), RW1 protein, etc.) were downregulated following co-stimulation of HPHAS and LPS. It is thought that microarrays will play an ever-growing role in the advance of our understanding of the pharmacological actions of HPHAS in the treatment of arthritis. Further studies, however, are required to concretely prove the effectiveness of HPHAS.

• BMB Reports
• /
• 제39권5호
• /
• pp.469-478
• /
• 2006

Vascular endothelial growth factor (VEGF)-A, a major regulator for angiogenesis, binds and activates two tyrosine kinase receptors, VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). These receptors regulate physiological as well as pathological angiogenesis. VEGFR2 has strong tyrosine kinase activity, and transduces the major signals for angiogenesis. However, unlike other representative tyrosine kinase receptors which use the Ras pathway, VEGFR2 mostly uses the Phospholipase-$C{\gamma}$-Protein kinase-C pathway to activate MAP-kinase and DNA synthesis. VEGFR2 is a direct signal transducer for pathological angiogenesis including cancer and diabetic retinopathy, thus, VEGFR2 itself and the signaling appear to be critical targets for the suppression of these diseases. VEGFR1 plays dual role, a negative role in angiogenesis in the embryo most likely by trapping VEGF-A, and a positive role in adulthood in a tyrosine kinase-dependent manner. VEGFR1 is expressed not only in endothelial cells but also in macrophage-lineage cells, and promotes tumor growth, metastasis, and inflammation. Furthermore, a soluble form of VEGFR1 was found to be present at abnormally high levels in the serum of preeclampsia patients, and induces proteinurea and renal dysfunction. Therefore, VEGFR1 is also an important target in the treatment of human diseases. Recently, the VEGFR2-specific ligand VEGF-E (Orf-VEGF) was extensively characterized. Interestingly, the activation of VEGFR2 via VEGF-E in vivo results in a strong angiogenic response in mice with minor side effects such as inflammation compared with VEGF-A, suggesting VEGF-E to be a novel material for pro-angiogenic therapy.

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

• Archives of Pharmacal Research
• /
• 제25권5호
• /
• pp.561-571
• /
• 2002

The action mechanisms of several chemopreventive agents derived from herbal medicine and edible plants have become attractive issues in cancer research. Tea is the most widely consumed beverage worldwide. Recently, the cancer chemopreventive actions of tea have been intensively investigated. It have been demonstrated that the active principles of tea were attributed to their tea polyphenols. Recently, tremendous progress has been made in elucidating the molecular mechanisms of cancer chemoprevention by tea and tea polyphenols. The suppression of various tumor biomarkers including growth factor receptor tyrosine kinases, cytokine receptor kinases, P13K, phosphatases, ras, raf, MAPK cascades, NㆍFB, IㆍB kinase, PKA, PKB, PKC, c-jun, c-fos, c-myc, cdks, cyclins, and related transducing proteins by tea polyphenols has been studied in our laboratory and others. The IㆍB kinase (IKK) activity in LPS-activated murine macrophages (RAW 264.7 cells) was found to be inhibited by various tea polyphenols including (-) epigallocatechin-3-gallate (EGCG), theaflavin (TF-1), theaflavin-3-gal-late (TF-2) and theaflavin-3,3'-digallate (TF-3). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other tea polyphenols. TF-3 inhibited both IKK1 and IKK2 activity and prevented the degradation of IㆍBㆍand IㆍBㆍin activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 and other tea polyphenols could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. TF-3 and other tea polyphenols blocked phosphorylation of IB from the cytosolic fraction, inhibited NFB activity and inhibited increases in inducible nitric oxide synthase levels in activated macrophage. TF-3 and other tea polyphenols also inhibited strongly the activities of xanthine oxidase, cyclooxygenase, EGF-receptor tyrosine kinase and protein kinase C. These results suggest that TF-3 and other tea polyphenols may exert their cancer chemoprevention through suppressing tumor promotion and inflammation by blocking signal transduction. The mechanisms of this inhibition may be due to the blockade of the mitogenic and differentiating signals through modulating EGFR function, MAPK cascades, NFkB activation as wll as c-myc, c-jun and c-fos expression.