• 제목/요약/키워드: C-myc

검색결과 191건 처리시간 0.037초

비소세포 폐암에서의 Microsatellite Instability와 p53. K-ras, c-myc 암단백의 발현 (Microsatellite Instability and p53, k-ras c-myc Oncoprotein Expression in Non-Small Cell Lung Carcinoma)

  • 나석주;곽문섭
    • Journal of Chest Surgery
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    • 제33권1호
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    • pp.60-67
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    • 2000
  • Background: Microsatellites are short-tandem repeated uncleotide sequences present throughout the human genome. Alterations of microsatellites have been termed microsatellite instability(MI). It has been generally known that microsatellite instability detected in hereditary non-polyposis colorectal cancer (HNPCC) reflects genetic instability that is caused by impairments of DNA mismatch repair system regarding as a novel tumorigenic mechanism. A number of studies reported that MI occurred at varying frequencies in non-small cell lung carcinoma (NSCLC). However It has been unproven whether MI could be a useful market of genetic instability and have a clinical significance in NSCLC. Material and Method : We have examined whether MI can be observed in thirty NCSLC using polymerase chain reaction whether such alterations are associated with other molecular changes such as p53, K-ras and c-myc oncoproteins expression detected by immunohistochemical stain,. Result: MI(+) was observed in 16.6%(5/30) and MI(-) was 83.3% (25/30) Average age was 50$\pm$7.5 year-old in MI(+) group and 57$\pm$6.6 year-old in MI(-) group. Two year survival rate in MI(=) group (20% 1/5) was worse than MI(-) group (64% 16/25) with a statistic difference. (P=0.04) The positive rate of K-ras oncoprotein expression and simultaneous expression of 2 or 3 oncoproteins expression were higher in MI(+) group than MI(-) group with a statistic difference(P=0.05, P=0.01) Conclusion: From, these results the authors can conclude that MI is found in some NSCLC and it may be a novel tumorigenic mechanism in some NSCLC. We also conclude that MI could be used as another poor prognostic factor in NSCLS.

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SKP2/P27Kip1 pathway is associated with Advanced Ovarian Cancer in Saudi Patients

  • Hafez, Mohamed M;Alhoshani, Ali R;Al-Hosaini, Khaled A;Alsharari, Shakir D;Al Rejaie, Salim S;Sayed-Ahmed, Mohamed M;Al-Shabanah, Othman A
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권14호
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    • pp.5807-5815
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    • 2015
  • Background: Ovarian cancer is the most common gynecological malignancy and constitutes the fifth leading cause of female cancer death. Some biological parameters have prognostic roles in patients with advanced ovarian cancer and their expression may contribute to tumor progression. The aim of this study was to investigate the potential prognostic value of SKP2, genes P27Kip1, K-ras, c-Myc, COX2 and HER2 genes expression in ovarian cancer. Materials and Methods: This study was performed on two hundred formalin fixed paraffin embedded ovarian cancer and normal adjacent tissues (NAT). Gene expression levels were assessed using real time PCR and Western blotting. Results: Elevated expression levels of SKP2, K-ras, c-Myc, HER2 and COX2 genes were observed in 61.5% (123/200), 92.5% (185/200), 74% (148/200), 96 % (192/200), 90% (180/200) and 78.5% (157/200) of cancer tissues, respectively. High expression of SKP2 and down-regulation of P27 was associated with advanced stages of cancer. Conclusions: The association between high expression of c-Myc and SKP2 with low expression of P27 suggested that the Skp2-P27 pathway may play an important role in ovarian carcinogenesis. Reduced expression of P27 is associated with advanced stage of cancer and can be used as a biological marker in clinical routine assessment and management of women with advanced ovarian cancer.

The Mechanism of t-Butylhydroperoxide-Induced Apoptosis in IMR-32 Human Neuroblastoma Cells

  • Kim, Jung-Ae;Lee, Yong-Soo;Huh, Keun
    • The Korean Journal of Physiology and Pharmacology
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    • 제3권1호
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    • pp.19-27
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    • 1999
  • Apoptosis has been implicated in the pathophysiological mechanisms of various neurodegenerative diseases. In a variety of cell types, oxidative stress has been demonstrated to play an important role in the apoptotic cell death. However, the exact mechanism of oxidative stress-induced apoptosis in neuronal cells is not known. In this study, we induced oxidative stress in IMR-32 human neuroblastoma cells with tert- butylhydroperoxide (TBHP), which was confirmed by significantly reduced glutathione content and glutathione reductase activity, and increased glutathione peroxidase activity. TBHP induced decrease in cell viability and increase in DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. TBHP also induced a sustained increase in intracellular $Ca^{2+}$ concentration, which was completely prevented either by EGTA, an extracellular $Ca^{2+}$ chelator or by flufenamic acid (FA), a non-selective cation channel (NSCC) blocker. These results indicate that the TBHP-induced intracellular $Ca^{2+}$ increase may be due to $Ca^{2+}$ influx through the activation of NSCCs. In addition, treatment with either an intracellular $Ca^{2+}$ chelator (BAPTA/AM) or FA significantly suppressed the TBHP-induced apoptosis. Moreover, TBHP increased the expression of p53 gene but decreased c-myc gene expression. Taken together, these results suggest that the oxidative stress-induced apoptosis in neuronal cells may be mediated through the activation of intracellular $Ca^{2+}$ signals and altered expression of p53 and c-myc.

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미강(Rice Bran) 추출물의 HL-60 백혈병 세포 Apoptosis 유도 효과 (The Effect of Rice Bran Extract on the Apoptosis Induction of HL-60 Leukemia Cells)

  • 김은지;문정선;강정일;이영기;고영상;유은숙;강희경;임동술
    • 생약학회지
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    • 제44권3호
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    • pp.269-274
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    • 2013
  • In this study, we investigated the anticancer effect of rice bran extract in HL-60 human promyelocytic leukemia cells. The extract of rice bran inhibited the proliferation of HL-60 cells. When treated with the rice bran extract, we could observe the apoptotic characteristics such as apoptotic bodies and the increase of sub-G1 hypodiploid cell population, increase of Bax level, decrease of Bcl-2 expression, cleavage of procaspase-3, cleavage of procaspase-9 and cleavage of poly(ADP-ribose) polymerase(PARP) in HL-60 cells. Furthermore, the apoptosis induction of HL-60 cells treated with the rice bran extract was also accompanied by the inactivation of mitogen-activated protein kinases (MAPK) such as ERK1/2 MAPK and p38 MAPK. In addition, the rice bran extract induced the down-regulation of c-myc. These data suggested that the rice bran extract could induce the apoptosis via the inactivation of ERK1/2 MAPK and p38 MAPK, and the down-regulation of c-myc in HL-60 acute pomyelocytic leukemia cells. The results support that the rice bran extract might have potential for the treatment of acute promyelocytic leukemia.

Gastrokine 1 Expression in the Human Gastric Mucosa Is Closely Associated with the Degree of Gastritis and DNA Methylation

  • Choi, Won Suk;Seo, Ho Suk;Song, Kyo Young;Yoon, Jung Hwan;Kim, Olga;Nam, Suk Woo;Lee, Jung Yong;Park, Won Sang
    • Journal of Gastric Cancer
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    • 제13권4호
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    • pp.232-241
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    • 2013
  • Purpose: Gastrokine 1 plays an important role in gastric mucosal defense. Additionally, the Gastrokine 1-miR-185-DNMT1 axis has been shown to suppress gastric carcinogenesis through regulation of epigenetic alteration. Here, we investigated the effects of Gastrokine 1 on DNA methylation and gastritis. Materials and Methods: Expression of Gastrokine 1, DNMT1, EZH2, and c-Myc proteins, and the presence of Helicobacter pylori CagA protein were determined in 55 non-neoplastic gastric mucosal tissue samples by western blot analysis. The CpG island methylation phenotype was also examined using six markers (p16, hMLH1, CDH1, MINT1, MINT2 and MINT31) by methylation-specific polymerase chain reaction. Histological gastritis was assessed according to the updated Sydney classification system. Results: Reduced Gastrokine 1 expression was found in 20 of the 55 (36.4%) gastric mucosal tissue samples and was closely associated with miR-185 expression. The Gastrokine 1 expression level was inversely correlated with that of DNMT1, EZH2, and c-Myc, and closely associated with the degree of gastritis. The H. pylori CagA protein was detected in 26 of the 55 (47.3%) gastric mucosal tissues and was positively associated with the expression of DNMT1, EZH2, and c-Myc. In addition, 30 (54.5%) and 23 (41.9%) of the gastric mucosal tissues could be classified as CpG island methylation phenotype-low and CpG island methylation phenotype-high, respectively. Reduced expression of Gastrokine 1 and miR-185, and increased expression of DNMT1, EZH2, and c-Myc were detected in the CpG island methylation phenotype-high gastric mucosa. Conclusions: Gastrokine 1 has a crucial role in gastric inflammation and DNA methylation in gastric mucosa.

Streptomyces endus YP-1이 생산하는 항암활성 물질의 분리 및 정제

  • 최성원;김병찬;최선진;김동섭;여익현;문순옥;오두환
    • 한국미생물·생명공학회지
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    • 제25권5호
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    • pp.483-489
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    • 1997
  • Sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, RNA dot blot and Northern hybridization analysis were performed to screen microorganisms for the production of anticancer agent. Among microorganisms tested, strain YP-1 was selected for its cytotoxicity and ability to reduce the level of c-myc RNA. Strain YP-1 was identified as Streptomyces endus. The anticancer material produced by Streptomyces endus YP-1 was sequentially purified by solvent extraction, silica gel column chromatograpby, preparative TLC and preparative HPLC. The cancer material identified as azalomycin B by the instrumental analyses such as $^{1}$H-NMR, $^{13}$C-NMR, Mass, IR and UV absorption. It was colorless amorphous powder and its molecular weight was 1025.278. Azalomycin B, produced by Streptomyces endus YP-1, showed anticancer activity against several human cancer cell lines and reduction of c-Myc protein level in Colo320 DM cells which was determined by Western blot analysis.

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남생이(Geoclemys reevesii) 대뇌에 있어서 raf Protein Kinase의 면역세포화학적 분포 (Immunocytochemical Localization Qf raf Protein Kinase in Cerebrum of Geoclemys reevesii (Gray))

  • 최원철;문현근
    • 한국동물학회지
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    • 제33권2호
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    • pp.141-151
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    • 1990
  • Raf protein kinases and protein kinase C는 세포질내 serine/threonine-specific protein에 속한다. 그리고 기능적인 구조와 세포내의 분포 양상은 서로 비슷하다. Raf family oncogene를 발현시키는 a-raf와 c-raf protein kinase에 대한 antibodies로써 남생이 대뇌의 raf protein kinase의 분포를 조사하였다. 일반적으로 raf protein kinase는 제한된 지역에서 즉,general pallium,hippocampal formation, pdmordiuin hippocampi,nucleus of lateral olfactory tract, basal amygdaloid nucleus와bed of stria terminalis에 나타났으며, c-raf protein kinase의 면역학적 labeling은 a-raf보다 그 범위가 넓었다. 그렇지만 labeling되는 intensity는 오히려 a-raf보다 낮았다. 그런데 a-raf에서 가장 명확한 좋은 예는 basal amygdaloid nucleus내의 구형모양의 세포인데, 이 세포는 세포질이 매우 강하게 labeling되어 지므로 ring모양과 같이 나타났다. 특히 c-raf는 protein kinase C 가 많이 나타나는 pyramidal 세포나 Purkinje세포에 많이 존재하는 것을 볼 때 protein kinase에 의하여 활성화되는 myc와 서로 상협작용을 유도한다고 제안하는 바이다.

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식이 Capsaicin이 마우스의 주요 장기조직에서의 Proto-oncogenes Expression에 미치는 영향 (Effect of Dietary Capsaicin on Proto-oncogenes Expression in Various in Mice)

  • 김정미;한인섭;김병삼;유리나
    • 한국식품영양과학회지
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    • 제25권6호
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    • pp.1024-1030
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    • 1996
  • 매운맛 성분(capsaicin, CAP)이 암발생에 미치는 영향에 대한 분자적인 수준에서의 기초 정보를 확보하기 위해, 식이 CAP의 투여가 동물 조직 중 proto-oncogene 의 발현에 미치는 영향을 조사하였다. ICR mouse를 4 group으로 분류하여 각각 식이CAP 농도가 0, 5, 20, 100ppm이 되도록 조제한 먹이로 4주 동안 사육하였다. 사육기간 종료 후 동물들의 중요장기를 적출하여 total RNA를 분리하고, proto-oncogene(c-jun, c-myc, H-ras, erbB, p53)의 발현 수준을 slot blot hybridization assay를 통해 살펴 보았다. 이때, control probe로는 18SrRNA를 사용하였다. 그 결과, c-jun proto-oncogene의 발현은 각 주요 장기조직에 따라 다른 양상을 나타내었는데, 식이CAP 투여량이 증가함에 따라 간과 신장에서 그 발현이 증가하며, 위에서는 CAP 20ppm까지는 c-jun의 발현이 증가하다. 100ppm 투여시에는 감소하는 것으로 나타났으며, 비장에서는 식이CAP 투여량이 증가함에 따라 감소하는 경향을 보였다. 한편, tumor suppressor gene인 p53의 경우, 간에서만 CAP 20, 100ppm 처리시 약하게 발현되었다. 이들 결과로 보아, 식이 CAP에 의한 proto-oncogene의 발현은 CAP 투여량에 따라 그 정도를 달리하며, 그 발현 정도는 조직 특이성을 나타내는 것으로 평가된다.

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