• Title/Summary/Keyword: p-53

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Oncogenic RUNX3: A Link between p53 Deficiency and MYC Dysregulation

  • Date, Yuki;Ito, Kosei
    • Molecules and Cells
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    • v.43 no.2
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    • pp.176-181
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    • 2020
  • The RUNX transcription factors serve as master regulators of development and are frequently dysregulated in human cancers. Among the three family members, RUNX3 is the least studied, and has long been considered to be a tumor-suppressor gene in human cancers. This idea is mainly based on the observation that RUNX3 is inactivated by genetic/epigenetic alterations or protein mislocalization during the initiation of tumorigenesis. Recently, this paradigm has been challenged, as several lines of evidence have shown that RUNX3 is upregulated over the course of tumor development. Resolving this paradox and understanding how a single gene can exhibit both oncogenic and tumor-suppressive properties is essential for successful drug targeting of RUNX. We propose a simple explanation for the duality of RUNX3: p53 status. In this model, p53 deficiency causes RUNX3 to become an oncogene, resulting in aberrant upregulation of MYC.

Apoptotic Cell Death by Pectenotoxin-2 in p53-Deficient Human Hepatocellular Carcinoma Cells (종양억제유전자 p53 결손 인체간암세포에서 Pectenotoxin-2에 의한 Apoptosis 유도)

  • Shin, Dong-Yeok;Kim, Gi-Young;Choi, Byung-Tae;Kang, Ho-Sung;Jung, Jee-H.;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.17 no.10
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    • pp.1447-1451
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    • 2007
  • Through the screening of marine natural compounds that inhibit cancer cell proliferation, we previously reported that pectenotoxin-2 (PTX-2) isolated from marine sponges exhibits selective cytotoxicity against several cell lines in p53-deficient tumor cells compared to those with functional p53. However, the molecular mechanisms of its anti-proliferative action on malignant cell growth are not completely known. To further explore the mechanisms of its anti-cancer activity and to test whether the status of p53 in liver cancer cells correlates with their chemo-sensitivities to PTX-2, we used two well-known hepatocarcinoma cell lines, p53-deficient Hep3B and p53-wild type HepG2. We have demonstrated that PTX-2 markedly inhibits Hep3B cell growth and induces apoptosis whereas HepG2 cells are much more resistant to PTX-2 suggesting that PTX-2 seems to act by p53-independent cytotoxic mechanism. The apoptosis induced by PTX-2 in Hep3B cells was associated with the modulation of DNA fragmentation factor (DFF) family proteins, up-regulation of pro-apoptotic Bcl-2 family members such as Bax and Bcl-xS and activation of caspases (caspase-3, -8 and -9). Blockade of the caspase-3 activity by caspase-3 inhibitor, z-DEVD-fmk, prevented the PTX-2-induced growth inhibition in Hep3B cells. Moreover, treatment with PTX-2 also induced phosphorylation of AKT and extracellular-signal regulating kinase (ERK), but not c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MARK). Specific inhibitors of PI3K inhibitor (LY294002) and ERK1/2 inhibitor (PD98059) significantly blocks PTX-2-induced-anti-proliferative effects, whereas a JNK inhibitor (SP600125) and a p38 MAPK inhibitor (SB203580) have no significant effects demonstrating that the pro-apoptotic effect of PTX-2 mediated through activation of AKT and ERK signal pathway in Hep3B cells.

Morphological Characteristics and Principal Component Analysis of Plums (자두의 형태적 특성과 주성분 분석에 의한 품종군 분류)

  • Chung, Kyeong-Ho
    • Horticultural Science & Technology
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    • v.17 no.1
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    • pp.23-28
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    • 1999
  • To examine taxonomic relationships among 53 plums derived from Prunus cerasifera, P. domestica, and P. salicina, principal component analysis (PCA) and cluster analysis on 27 morphological characters were conducted. Of 27 characters, leaf size, leaf shape, and leaf hair were useful characters for plum identification and understanding of taxonomic relationships among them. Leaf length, petiole length, number of leaf nectaries, leaf shape, leaf base, and date of full blooming showed the clear differences between P. salicina group and P. domestica group. Results of cluster analysis using scores of the first three principal components indicated that 53 plums could be grouped into P. salicina-P. cerasifera, P. domestica, and P. spinosa phenon at 1.0 of average distance in UPGMA. Although PCA was useful for rough classification of plums, much more characters were needed for the exact classification.

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Association Between p53 codon 72 Polymorphism and Cervical Cancer Risk Among Asians: a Huge Review and Meta-analysis

  • Zhou, Xin;Gu, Yang;Zhang, Shu-Lan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.4909-4914
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    • 2012
  • Objective: The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to derive a more precise estimation of the association between p53 codon 72 polymorphism (Arg72Pro, rs1042522 G>C) and cervical cancer risk among Asians. Methods: A literature search of Pubmed, Embase, Web of Science and CBM databases from inception through June 2012 was conducted. The meta-analysis was performed using STATA 12.0 software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of any association. Twenty-eight case-control studies were included with a total of 3,580 cervical cancer cases and 3,827 healthy controls. When all the eligible studies were pooled into the meta-analysis, the results showed that the Pro/Pro genotype was associated with increased risk of cervical cancer under the heterozygous model (Pro/Pro vs. Arg/Pro: OR = 1.25, 95%CI: 1.02-1.53, P= 0.005). However, no statistically significant associations were found under four other genetic models (Pro vs. Arg: OR = 0.97, 95%CI: 0.85-1.10, P= 0.624; Pro/Pro + Arg/Pro vs. Arg/Arg: OR = 0.84, 95%CI: 0.70-1.01, P= 0.058; Pro/Pro vs. Arg/Arg + Arg/Pro: OR = 1.13, 95%CI: 0.92-1.39, P= 0.242; Pro/Pro vs. Arg/Arg: OR = 0.97, 95%CI: 0.76-1.22, P= 0.765; respectively). In the subgroup analysis based on country, the Pro/Pro genotype and Pro carrier showed significant associations with increased risk of cervical cancer among Indian populations, but not among Chinese, Japanese and Korean populations. Conclusion: Results from the current meta-analysis suggests that p53 codon 72 polymorphism might be associated with increased risk of cervical cancer, especially among Indians.

Analysis of p53 and Retinoblasoma(Rb) Gene Polymorphisms in Relation to Lung Cancer in Koreans (한국인 폐암 환자에 대한 p53 및 Rb유전자의 다형성 분석)

  • Lee, Kyung-Sang;Sohn, Jang-Won;Yang, Suck-Chul;Yoon, Ho-Joo;Shin, Dong-Ho;Park, Sung-Soo;Lee, Jung-Hee;Lee, Chun-Geun;Cho, Youl-Hee
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.3
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    • pp.534-546
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    • 1997
  • Background : The p53 and retinoblastoma(Rb) tumor suppressor genes are associated with the pathogenesis of several types of human cancer. Substantial proportion of the primary lung cancers or cell lines have been reported to have the p53 and/or the Rb gene mutations. But, so far there is no report on the analysis of the Rb gene polymorphism as one of the genetic susceptibility marker. This study was undertaken to establish the gene frequencies of the polymorphic genotypes of the p53 and Rb genes in Koreans to evaluate the possible involvement of these genotypes as a risk factor of lung cancer. Methods : In this study 145 controls without previous and present tumor history and 128 lung cancer patients were subjected to analysis. The two intragenic polymorphisms of the p53 gene(exon 4/ AccII, intron 6/MspI) and one intron 17/XbaI polymorphism of the Rb gene were analysed by the method of polymersae chain reaction- restriction fragment length polymorphisms(PCR-RFLPs). The genotype of the intron 3/16 bp repeat polymorphism of p53 was determined by PCR and direct gel electrophoresis. Results : There were no significant differences in the genotype distributions of the p53 gene between lung cancer patients and controls. But heterozygotes(Arg/Pro) of the exon 4/AccII polymorphisms were slightly over-represented than controls, especially in the Kreyberg type I cancer, which was known to be associated with smoking. The intron 3/16 bp duplication and the intron 6/MspI polymorphisms were in complete linkage disequilibrium. About 95% of the individuals were homozygotes of the common alleles both in the 16 duplication and MspI polymorphisms, and no differences were deteced in the genotype distributions between lung cancer patients and controls. Overall genotype distributions of the Rb gene polymorphisms between lung cancer patients and controls were not significantly different However, the genotype distributions in the Kreyberg type I cancer were significantly different from those of controls(p = 0.0297) or adenocarcinomas(p = 0.0008). It was noticeable that 73.4% of the patients with adenocarcinomas were heterozygotes(r1/r2) whereas 39.2% of the Kreyberg type I cancer were heterozygous at this polymorphisms. In the lung cancer patients, significant differences were also noted between the high dose smokers and low dose smokers including non-smokers(p = 0.0258). The relative risk to Kreyberg type I cancer was significantly reduced in the individuals with the genotype of r1/r2(odds ratio = 0.46, 95% C.I. = 0.25-0.86, p = 0.0124). The combined genotype distribution of the exon 4 AccII of the p53 and the intron 17 Rb gene polymorphisms in Kreyberg type I cancers were significantly different from dose of controls or adenocarcinomas. The highest odds ratio were observed in the individuals with the genotypes of Arg/Pro and r2/r2(odds ratio = 1.97,95% C.I. = 0.84-4.59) and lowest one was in the patients with Arg/Arg, r1/r2 genotype(odds ratio = 0.54, 95% C.I. = 0.25-1.14). Conclusion : The p53 and the Rb gene polymorphisms modulate the risk of smoking induced lung cancer development in Koeans. However, the exact mechanism of risk modulation by these polymorphism remains to be determined. For more discrete clarification of associations between specific genotypes and lung cancer risk, the evaluations of these polymorphisms in other ethnics and more number of patients will be needed.

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Impact of AhR, CYP1A1 and GSTM1 Genetic Polymorphisms on TP53 R273G Mutations in Individuals Exposed to Polycyclic Aromatic Hydrocarbons

  • Gao, Meili;Li, Yongfei;Xue, Xiaochang;Long, Jiangang;Chen, Lan;Shah, Walayat;Kong, Yu
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2699-2705
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    • 2014
  • This study was to undertaken to investigate the impacts of AhR, CYP1A1, GSTM1 genetic polymorphisms on the R273G mutation in exon 8 of the tumor suppressor p53 gene (TP53) among polycyclic aromatic hydrocarbons (PAHs) exposed to coke-oven workers. One hundred thirteen workers exposed to PAH and 82 control workers were recruited. We genotyped for polymorphisms in the AhR, CYP1A1, GSTM1, and TP53 R273G mutation in blood by PCR methods, and determined the levels of 1-hydroxypyrene as PAH exposure marker in urine using the high pressure liquid chromatography assay. We found that the distribution of alcohol users and the urinary excretion of 1-OHP in the exposed workers were significantly higher than that of the control workers (p=0.004, p<0.001, respectively). Significant differences were observed in the p53 genotype distributions of smoking subjects (p=0.01, 95%CI: 1.23-6.01) and PAH exposure (p=0.008, 95%CI: 1.24-4.48), respectively. Further, significant differences were observed in the p53 exon 8 mutations for the genetic polymorphisms of Lys/Arg for AhR (p=0.02, 95%CI: 0.70-15.86), Val/Val for CYP1A1 (p=0.04, 95%CI: 0.98-19.09) and null for GSTM1 (p=0.02, 95%CI: 1.19-6.26), respectively. Our findings indicated that polymorphisms of PAH metabolic genes, such as AhR, CYP1A1, GSTM1 polymorphisms may interact with p53 genetic variants and may contribute to PAH related cancers.

Analysis of the bcl-2, Ki-67 and p53 Expression Level Based on the Gleason Score Group of Prostate Adenocarcinoma

  • Kim, Tai-Jeon;Kim, Sung-Chul
    • Biomedical Science Letters
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    • v.14 no.3
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    • pp.157-165
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    • 2008
  • Recently, the number of patients with prostate cancer has been increased gradually by both the change of living environment and the increase of aged population. In this study the serum prostate specific antigen (PSA) level was compared to the Gleason score known as a prognostic factor for the prostate cancer. In the Gleason score 6 and $9{\sim}10$, the average age was 69.68 years old and 69.52 years old, respectively and there was no statistically difference in both of age and Gleason score. the PSA serum consistency appeared <4 ng/mL as example 1, $4{\sim}20ng/mL$ as example 17 and ${\geq}20ng/mL$ as example 4 in the Gleason score 6, and In the Gleason score $9{\sim}10$, it appeared <4 ng/mL as example 1, $4{\sim}20ng/mL$ as example 6 and ${\geq}20ng/mL$ as example 15. PSA serum consistency in the Gleason score $9{\sim}10$ showed higher value than those of Gleason score 6 (P<0.05). Next, expression ratios of bcl-2, Ki-67 and p53 were examined in the Gleason score 6 and $9{\sim}10$. the p53 expression ratio, a tumor suppression gene, appeared the significance statistically by the classification of the Gleason score as example 7 (28%) in the Gleason score 6 and as example 16 (64%) in the Gleason score $9{\sim}10$ (P<0.05). but not different in the expression ratios of the Ki-67 and bcl-2. The expression ratio of p53 by the expression ratio of bcl-2 and the expression ratio of Ki-67 by the expression ratio of p53 had a positive relationship in all of the Gleason score 6 and the Gleason score $9{\sim}10$ (P<0.05). However, the expression ratio of Ki-67 by the expression ratio of bcl-2 did not show any significance in the Gleason score $9{\sim}10$ (P<0.05). Therefore, the results suggested that p53 expression could be used as an independent prognostic factor.

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Snail Switches 5-FU-induced Apoptosis to Necrosis through Akt/PKB Activation and p53 Down-regulation (Snail의 Akt/PKB의 활성화와 p53의 downregulation를 통한 5-FU-induced apoptosis의 necrosis로의 전환)

  • Lee, Su-Yeon;Jeon, Hyun-Min;Ju, Min-Kyung;Kim, Cho-Hee;Jeong, Eui-Kyong;Park, Hye-Gyeong;Kang, Ho-Sung
    • Journal of Life Science
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    • v.22 no.8
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    • pp.1018-1023
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    • 2012
  • Snail is a zinc finger transcription factor that induces epithelial-to-mesenchymal transition (EMT), which promotes tumor invasion and metastasis by repressing E-cadherin expression. In addition, Snail restricts the cellular apoptotic response to apoptotic stimuli or survival factor withdrawal; however, its molecular mechanism remains largely unknown. In this study, we have investigated the mechanism underlying Snail-mediated chemoresistance to 5-fluorouracil (5-FU), one of the most widely used anti-cancer drugs. When Snail was overexpressed by doxycycline (DOX) in MCF-7 #5 cells, it inhibited 5-FU-induced apoptotic cell death and switched the cell death mode to necrosis. Snail expression, either by DOX treatment in MCF-7 #5 cells or by the transfection of Snail expression vectors pCR3.1-Snail-Flg, phosphorylation-resistant pCR3.1-S104, and 107A Snail-Flg in MCF-7 cells specifically induced PTEN down-regulation/inactivation and Akt/PKB activation, without affecting ERK1/2 activity. In addition, Snail prominently suppressed 5-FU-induced increases in p53 levels. These findings demonstrate that Snail switches 5-FU-induced apoptosis to necrosis through the activation of Akt/PKB and the down-regulation of p53 levels.

Inhibitory Effect of Bojungbangam-tang Kakambang on Cisplatin-Induced G2/M Phase Arrest in Human Renal Proximal Tubular HK-2 Cells (보정방암탕가감방(保正防癌湯加減方)이 cisplatin으로 유도된 인간 근위세뇨관 HK-2세포의 G2/M phase arrest에 미치는 영향)

  • Park, Sung-Cheul;Lee, Su-Kyung;Yeom, Seung-Ryong;Kwon, Young-Dal;Song, Yung-Sun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.6
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    • pp.1555-1563
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    • 2007
  • To idenifty effect of Bojungbangam-tang kakambang on Cisplatin-Induced G2/M Phase Arrest in Human Renal Proximal Tubular HK-2 Cells. Cytotoxicity of cisplatin was detected in HK-2 cells and the value of IC50 is about $25\;{\mu}M$. The treatment of cisplatin to HK-2 showed the G2/M phase cell cycle arrest. The ethanol extract of Bojungbangam-tang kakambang (EBTKB), a new herbal prescription composed of ten crude herbs, inhibited cisplatin-induced G2/M phase arrest in HK-2 cells. EBTKB increased G0/G1 peak in cisplatin-treated HK-2 cells. p53, p21 and p27 expression were increased in cisplatin-treated HK-2 cells. Inhibitory effect of EBTKB on cisplatin-induced G2/M phase arrest was accomplished through inhibition of p53, p21 and p27 expression. Also, reduced CDK2 and cyclin A expression by cisplatin were increased by EBTKB, but cyclin E was not changed. Reduction of ERK activation and increment of p38 activation by cisplatin were increased ERK activation and decreased p38 activation by EBTKB. Cisplatin had no effect on JNK activation, but EBTKB increased JNK activation. These results can suggest that EBTKB inhibits cisplatin-induced G2/M phase arrest in HK-2 cell through reduction of p53-dependent p21 and p27 protein, ERK activation and p38 inactivation.

Correlations between Expression of Tumor-Related Proteins and COX-2 in Gastric Cancer (위암에서 종양관련 단백질들과 COX-2 발현의 상관성)

  • Yu, Suk;Noh, Jeong-Hwan;Kim, Jong-Yull
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.3
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    • pp.231-240
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    • 2007
  • It has been reported the higher incidence rate of gastric cancer in our country. Helicobacter pylori (H. pylori), that exhibited a higher infection rate among Korean people, has been known as a cofactor to cause cancer. Therefore, the aim of this study was to identify correlations among overexpressions of COX-2 (Cyclooxygenase-2) gene, p53 mutation and cell proliferation index related to H. pylori. Taking 28 cases of gastric cancer with H. pylori detection, immunohistochemical staining for COX-2, p53 and Ki-67 were performed. In the H. pylori positive group, the well differentiated type and diffuse type of gastric cancer were distributed in larger area and the expression rate of COX-2 was revealed high. The H. pylori negative group showed higher p53 expression than that of the positive group. However, the statistical correlation between H. pylori and histopathological factors was not observed. The significantly higher expression of COX-2 had were observed in both well differentiated type and the intestinal type of gastric cancer. Although there were no statistical significances, this showed a higher inclination of manifest in the early gastric cancer. p53 exhibited a higher tendency of expression in the well differentiated, moderately differentiated and the intestinal type of gastric cancers including the early gastric cancer. Ki-67 was expressed in a significantly higher fashion along with the increase of age. In addition, it was significantly expressed in well differentiated type and intestinal type of gastric cancer. Therefore, these results suggest that H. pylori, COX-2, p53, and Ki-67 influences on the new occurrence of gastric cancer and its development procedures. In the future, the more researches would be required to focus on a larger category relative to gene expressions in gastric cancer.

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