• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.114-114
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• 2003

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.139-139
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• 2004

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.483-489
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• 2009

Despite the potential importance of the human regulator of calcineurin 1 (RCAN-1) gene in the modulation of cell survival under stress, little is known about its role in death-inducing signal pathways. In this study, we addressed the effects of RCAN1.4 knockdown on cellular susceptibility to apoptosis and the activation of death pathway proteins. Transfection of siRNAs against RCAN1.4 resulted in enhanced Fas- and etoposide-induced apoptosis, which was associated with increased expression and translocation of Bax to mitochondria. Our results suggest that enhanced expression and activation of p53 was responsible for the upregulation of Bax and the increased sensitivity to apoptosis, which could be reversed by p53 knockdown. To explain the observed upregulation of p53, we propose a downregulation of the ubiquitin ligase HDM2, probably translationally. These findings show the importance of appropriate RCAN1.4 expression in the modulation of cell survival and reveal a link between RCAN1.4 and p53.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7413-7417
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• 2014

Background: Development of gastric cancer (GC) is a multistep process that requires alterations in the expression of oncogenes and tumor suppressor genes, occurring over several decades. The p53 tumor suppressor protein is involved in cell-cycle control, apoptosis and DNA repair. One of the most important regulators of p53 is MDM2, which acts as a negative regulator in the p53 pathway. Based on the key role of p53 and MDM2 in tumor suppression, polymorphisms that cause change in their function might affect cancer risk. We therefore elevated associations of the polymorphisms of p53 (R72P) and MDM2 (SNP309) with GC in Iran. Materials and Methods: A total of 104 patients with gastric cancer and 100 controls were recruited. Genomic DNA was extracted from fresh gastric samples. Genotyping of the p53 and MDM2 genes was performed using allele specific PCR (AS-PCR). Results: There was no significant difference between the p53 codon 72 polymorphism distribution in control and patient groups (p=0.54), but the G allele of MDM2 was found to be over-represented in patients (p=0. 01, Odds Ratio=2. 08, 95% Confidence Interval= 1.37-4.34). Conclusions: The p53 R72P seems not to be a potential risk factor for development of GC among Iranian patients, but our data suggest that MDM2 SNP309 might modify the risk related to GC.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.584-590
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• 2017

Ginkgo biloba extract (EGb 761) has been widely used clinically to reduce myocardial ischemia reperfusion injury (MIRI). Microvascular endothelial cells (MVECs) may be a proper cellular model in vitro for the effect and mechanism study against MIRI. However, the protective effect of EGb 761 on MVECs resisting hypoxia/reoxygenation (H/R) injury is little reported. In this study, H/R-injured MVECs were treated with EGb 761, and then the cell viability, apoptosis, ROS production, SOD activity, caspase-3 activity, and protein level of ATM, ${\gamma}$-H2AX, p53, and Bax were measured. ATM siRNA was transfected to study the changes of protein in the ATM pathway. EGb 761 presented protective effect on H/R-injured MVECs, with decreasing cell death, apoptosis, and ROS, and elevated SOD activity. Next, EGb 761 could inhibit H/R-induced ATM, ${\gamma}$-H2AX, p53, and Bax in a dose-dependent manner. Moreover, ATM siRNA also could inhibit H/R-induced ATM, ${\gamma}$-H2AX, p53, and Bax. Overall, these findings verify that EGb 761 protects cardiac MVECs from H/R injury, and for the first time, illustrate the influence on the ATM pathway and apoptosis by EGb 761 via dampening ROS.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.105-105
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• 2001

• Molecules and Cells
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• v.41 no.6
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• pp.532-544
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• 2018

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. In order to investigate a new treatment fot GIST, we hypothesized the effect of miR-374b targeting PTEN gene-mediated PI3K/Akt signal transduction pathway on proliferation and apoptosis of human gastrointestinal stromal tumor (GIST) cells. We obtained GIST tissues and adjacent normal tissues from 143 patients with GIST to measure the levels of miR-374b, PTEN, PI3K, Akt, caspase9, Bax, MMP2, MMP9, ki67, PCNA, P53 and cyclinD1. Finally, cell viability, cell cycle and apoptosis were detected. According to the KFGG analysis of DEGs, PTEN was involved in a variety of signaling pathways and miRs were associated with cancer development. The results showed that MiR-374b was highly expressed, while PTEN was downregulated in the GIST tissues. The levels of miR-374b, PI3K, AKT and PTEN were related to tumor diameter and pathological stage. Additionally, miR-374b increased the mRNA and protein levels of PI3K, Akt, MMP2, MMP9, P53 and cyclinD1, suggesting that miR-374b activates PI3K/Akt signaling pathway in GIST-T1 cells. Moreover, MiR374b promoted cell viability, migration, invasion, and cell cycle entry, and inhibited apoptosis in GIST cells. Taken together, the results indicated that miR-374b promotes viability and inhibits apoptosis of human GIST cells by targeting PTEN gene through the PI3K/Akt signaling pathway. Thus, this study provides a new potential target for GIST treatment.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.152.2-153
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• 2003

${\beta}Although$ it has been demonstrated that $p2l^{WAFl/Cip1}$, a well known cell cycle inhibitor, could be induced by $TGF-{\beta}$ in a p53-independent manner, the detailed signal transduction pathways still remain poorly understood. In this study, we show that ERK is required for $TGF-{\beta}$ induction of $p21^{WAF1/Cip1}$, but JNK or p38 MAPK is not. ERK activation by $TGF-{\beta}$ significantly attenuated by treatment with ROS scavenger such as NAC or catalase, indicating that ROS, mainly $H_2O_2$, generation by $TGF-{\beta}$ might stimulate ERK signaling pathway to require the induction of $p21^{WAF1/Cip1}$. (omitted)

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.452-459
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• 2012

This study was conducted in order to investigate the effect of resveratrol on the induction of apoptosis in MDA-MB-231 breast cancer cells. The result of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl terazolium bromide (MTT) assay shows that cell viability significantly decreased in a dose and time-dependent manner. 4',6-diamidino-2-phenylindole (DAPI) staining shows significantly increased chromatin condensation in a dose and time-dependent manner. Resveratrol increased the expression of p53, cleaved-caspase-3, and cleaved-caspase-9, whereas the expression of PI3K/Akt decreased in a time-dependent manner. We investigated the in vivo tumor growth inhibitory effect of resveratrol. Tumor volume was significantly decreased in the 50 mg/kg resveratrol-administration group compared to the control group. In the 50 mg/kg treated group. Apoptosis cells were frequently observed by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay. Immunohistochemistry staining shows increased the expression of p53, cytochrome-C, and cleaved-caspase-3 in the 50 mg/kg treated group. These results indicate that resveratrol induced apoptosis through PI3K/Akt and p53 signal pathway in MDA-MB-231 cell.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2313-2318
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• 2014

Peroxisome proliferator-activated receptor gamma (PPAR-${\gamma}$), a ligand-dependent nuclear transcription factor, has been found to widely exist in tumor tissues and plays an important role in affecting tumor cell growth. In this study, we investigated the effect of PPAR-${\gamma}$ on aspects of the cervical cancer malignant phenotype, such as cell proliferation and apoptosis. Cell growth assay, Western blotting, Annexin V and flow cytometry analysis consistently showed that treatment with troglitazone (TGZ, a PPAR-${\gamma}$ agonist) led to dose-dependent inhibition of cervical cancer cell growth through apoptosis, whereas T0070907 (another PPAR-${\gamma}$ antagonist) had no effect on Hela cell proliferation and apoptosis. Furthermore, we also detected the protein expression of p53, p21 and Mdm2 to explain the underlying mechanism of PPAR-${\gamma}$ on cellular apoptosis. Our work, finally, demonstrated the existence of the TGZ-PPAR-${\gamma}$-p53 signaling pathway to be a critical regulator of cell apoptosis. These results suggested that PPAR-${\gamma}$ may be a potential therapeutic target for cervical cancer.