• The Korean Journal of Physiology and Pharmacology
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• v.14 no.6
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• pp.365-369
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• 2010

In this study, we examined whether melatonin promotes apoptotic cell death via p53 in prostate LNCaP cells. Melatonin treatment significantly curtailed the growth of LNCaP cells in a dose- and time-dependent manner. Melatonin treatment (0 to 3 mM) induced the fragmentation of poly(ADP-ribose) polymerase (PARP) and activation of caspase-3, caspase-8, and caspase-9. Moreover, melatonin markedly activated Bax expression and decreased Bcl-2 expression in dose increments. To investigate p53 and p21 expression, LNCaP cells were treated with 0 to 3 mM melatonin. Melatonin increased the expressions of p53, p21, and p27. Treatment with mitogen-activated protein kinase (MAPK) inhibitors, PD98059 (ERK inhibitor), SP600125 (JNK inhibitor) and SB202190 (p38 inhibitor), confirmed that the melatonin-induced apoptosis was p21-dependent, but ERK-independent. With the co-treatment of PD98059 and melatonin, the expression of p-p53, p21, and MDM2 did not decrease. These effects were opposite to the expression of p-p53, p21, and MDM2 observed with SP600125 and SB202190 treatments. Together, these results suggest that p53-dependent induction of JNK/p38 MAPK directly participates in apoptosis induced by melatonin.

• BMB Reports
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• v.43 no.6
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• pp.432-437
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• 2010

LBH is a transcription factor as a candidate gene for CHD associated with partial trisomy 2p syndrome. To identify potential LBH-interacting partners, a yeast two-hybrid screen using LBH as a bait was performed with a human heart cDNA library. One of the clones identified encodes ${\alpha}B$-crystallin. Co-immunoprecipitation and GST pull-down assays showed that LBH interacts with ${\alpha}B$-crystallin, which is further confirmed by mammalian two-hybrid assays. Co-localization analysis showed that in COS-7 cells, ${\alpha}B$-crystallin that is cytoplasmic alone, accumulates partialy in the nucleus when co-transfected with LBH. Transient transfection assays indicated that overexpression of LBH or ${\alpha}B$-crystallin reduced the transcriptional activities of p53 and p21, respectively, Overexpression of both ${\alpha}B$-crystallin and LBH together resulted in a stronger repression of the transcriptional activities of p21 and p53. These results showed that the interaction of LBH and ${\alpha}B$-crystallin may inhibit synergistically the transcriptional regulation of p53 and p21.

• Proceedings of the Korean Society of Life Science Conference
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• 2000.12a
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• pp.39-43
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• 2000

HBV는 인체에 감염하여 간염, 간경변 및 간암을 유발하는 hepadnaviruses의 일종으로써 임상적으로 매우 중요한 바이러스이다. 그러나 이 바이러스에 의한 간암(HCC)의 발생 메커니즘은 아직 불확실하다. 최근에는 HBV의 X 단백질(HBx)이 간암 발생에 중요한 역할을 수행하는 것으로 보고되고 있다. HBx 단백질은 전사 활성인자(transcriptional activator)로써 숙주세포의 유전자발현에 영향을 미치어 세포증식 및 분화에 영향을 줄 수 있다. 본 연구에서는 HBx 단백질이 NIH 3T3 cell의 증식 및 형질전환에 미치는 영향을 조사하였다. HBx 단백질을 발현하는 세포주는 정상세포에 비하여 증식 속도가 2배 정도 빠르며, soft agar assay 결과에 의하면 대조군과 비교하여 더 많은 수의 colony를 형성하였다. 또한, 이들 HBx 발현 세포들은 접촉 저해 능력을 상실하여 HBx가 세포 형질 전환 능력을 가짐을 알수 있다 또한 HBx 발현 세포주에 있어서 p21의 RNA 및 protein수준이 정상세포에 비하여 낮으므로 HBx에 의한 증식 촉진 및 세포 형질 전환이 p21을 매개하여 이루어 짐을 알 수 있었다. HBx에 의한 p21 유전자의 발현 감소는 p21의 전사 수준에서 이루어지며 이는 p53-비의존적 경로에 의하여 이루어졌다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.199-205
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• 2003

The p53 protein was discovered in 1979 as cellular 53-kD nuclear phosphoprotein bound to the large transforming antigen of SV40 virus. $P21^{WAF1/CIP1}$, which has been described as the critical downstream mediator of p53, is known to suppress DNA replication and arrest the G1 cell cycle by quaternary complex with cyclin D, cyclin-dependent kinase(CDK) and proliferating cell nuclear antigen(PCNA). In these days, some studies shows that the p21 can be induced by independent pathways. There are various reports about the expression of p21 (67%.82.4%) in oral squamous cell carcinoma. But these studies are mostly done in malignant tumor not in benign tumor. So we decided to study the expression of p21 in ameloblastoma and the relationship between p53 and p21 as a downstream mediator of p53 in ameloblastoma. We investigated the expression of p21 and p53 with the method of immunohistochemistry. We selected 30 cases of ameloblastoma tissue blocks (acanthomatous type: 5 cases, follicular type: 8 cases, plexiform type: 17 cases) imbedded in paraffin. We used 30 cases of normal gingival tissues and 30 cases of squamous cell carcinoma tissues (SCC) respectively and compared their results with those of ameloblastoma. We made slides with the streptavidin-biotin methods and used monoclonal antibody DO-7 (Novocastra, Newcastle, United Kingdom) as p53 antibody and monoclonal antibody M7202 (DAKO, California, U.S.A.) as p21 antibody. We used Pearson's correlation coefficient to analyse the relationship. The results were as follows: 1. p21 was expressed in ameloblastoma about 30% and this is lower than that of normal gingiva and SCC. 2. In normal gingiva and ameloblastoma, p21 expression was correlated with p53 expression. 3. In SCC, p21 were expressed about 83.3% and this is more than that of p53. But there was no correlation between p21 and p53 expression. We confirmed p21 expression and relation with p53 in ameloblastoma. But, to confirm the function of p21, more studies about p21 expression in malignant ameloblastoma and ameloblastic carcinoma are needed.

• BMB Reports
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• v.43 no.5
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• pp.355-362
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• 2010

The sterile alpha motif (SAM) is a putative protein interaction domain involved in a wide variety of biological processes. Here we report the identification and characterization of a novel gene, SAMD4B, which encodes a putative protein of 694 amino acids with a SAM domain. Northern blot and RT-PCR analysis showed that SAMD4B is widely expressed in human embryonic and adult tissues. Transcriptional activity assays show SAMD4B suppresses transcriptional activity of L8G5-luciferase. Over-expression of SAMD4B in mammalian cells inhibited the transcriptional activities of activator protein-1 (AP-1), p53 and p21, and the inhibitory effects can be relieved by siRNA. Deletion analysis indicates that the SAM domain is the main region for transcriptional suppression. The results suggest that SAMD4B is a widely expressed gene involved in AP-1-, p53- and p21-mediated transcriptional signaling activity.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.359-373
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• 2023

This study examined the α-glucosidase inhibitory, and apoptosis- and anti-muscular-related factors of goat meat extracts from forelegs, hind legs, loin, and ribs. The goat meat extracts were evaluated for their α-glucosidase inhibitory activity. The gene and protein expression levels of Bcl-2-associated X (bax), p53, and p21 were examined by reverse transcription polymerase chain reaction (RT-PCR) and immunoblotting in AGS and HT-29 cells. The expression levels of Atrogin-1 and MHC1b were examined by RT-PCR in C2C12 myoblasts, and the expression levels of Atrogin-1, muscle atrophy F-box (MAFbx), muscle RING-finger protein-1 (MuRF-1), and myosin heavy chain-7 were investigated by immunoblotting. α-Glucosidase inhibitory activity was higher in ethanol extract than in hydrous and hot water extracts. BAX and p53 expression levels were higher (p<0.05) in AGS cells treated with goat meat extract than those of cells treated with no goat meat extract. In HT-29 cells, the protein expression levels of BAX, p53, and p21 were higher (p<0.05) in the cells treated with goat meat extract than those of cells not treated with goat meat extract. In dexamethasone-treated C2C12 cells, goat meat extract treatment lower (p<0.05) the expression of Atrogin-1 and lower (p<0.05) the expression of MAFbx and MuRF-1. The results of the present study indicate that goat meat extracts have α-glucosidase inhibitory activity in vitro. In addition, apoptosis was induced in AGS cells and HT-29 cells treated with goat meat extract, and anti-muscular atrophy activity was also observed in C2C12 cells treated with goat meat extract.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.70-77
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• 1999

Purpose : The expression of p53, P211WAF/CIP, Bcl-2, and Bax underlying the radiation-induced apoptosis in different pH environments using SCK mammary adenocarcinoma cell line was investigated. Materials and Methods Mammary adenocarcinoma cells of hi) mice (SCK cells) in exponential growth phase were irradiated with a linear accelerator at room temperature. The cells were irradiated with 12 Gy and one hour later, the media was replaced with fresh media at a different pHs. After Incubation at 37Microbioiogy, College of Medicine Dong A University for 0$\~$48 h, the extort of apoptosis was determined using agarose gel electrophoresis and flow cytometry. The progression of cells through the cell cycle after irradiation in different pHs was also determined with flow cytometry. Western blot analysis was used to monitor p53, p211WAFfCIP, Bcl-2, and Bu protein levels. Results : The induction of apoptosis by irradiation in pH 6.6 medium was markedly less than that in pH 7.5 medium. The radiation-induced G2IM arrest in pH 6.6 medium lasted markedly longer than that in pH 7.5 medium. Considerable amounts of p53 and p21 proteins already existed at pH 7.5 and increased the level of p53 and p21 significantly after 12 Gy X-irradiation. An incubation at pH 6.6 after 12 Gy X-irradiation did not change the level of p53 and p21 protein levels significantly. Bcl-2 proteins were not significantly affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis in different pHs. An exposure to 12 Gy of X-rays increased the level of Bax protein at pH 7.5 but at pH 6.6, it was slight. Conclusions : The molecular mechanism underlying radiation-induced apoptosis in dinerent pH environments using SCK mammary adenocarcinoma cell line was dependent of the expression p53 and P211YVAF/CIP proteins. We may propose following hypothesis that an acidic stress augments the radiation-induced G2iM arrest, which inhibiting the irradiated cells undergo post-mitotic apoptosis. The effects of environmental acidity on anti-apoptotic and pro-apoptotic function of Bcl-2 family was unclear in SCK mammary adenocarcinoma cell line.

• BMB Reports
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• v.53 no.5
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• pp.272-277
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• 2020

Protein kinase CK2 downregulation induces premature senescence in various human cell types via activation of the reactive oxygen species (ROS)-p53-p21^Cip1/WAF1 pathway. The transcription factor "nuclear factor erythroid 2-related factor 2" (Nrf2) plays an important role in maintaining intracellular redox homeostasis. In this study, Nrf2 overexpression attenuated CK2 downregulation-induced ROS production and senescence markers including SA-β-gal staining and activation of p53-p21^Cip1/WAF1 in human breast (MCF-7) and colon (HCT116) cancer cells. CK2 downregulation reduced the transcription of Nrf2 target genes, such as glutathione S-transferase, glutathione peroxidase 2, and glutathione reductase 1. Furthermore, CK2 downregulation destabilized Nrf2 protein via inhibiting autophagic degradation of Kelch-like ECH-associated protein 1 (Keap1). Finally, CK2 downregulation decreased the nuclear import of Nrf2 by deactivating AMP-activated protein kinase (AMPK). Collectively, our data suggest that both Keap1 stabilization and AMPK inactivation are associated with decreased activity of Nrf2 in CK2 downregulation-induced cellular senescence.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.139-148
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• 1999

Oral cancer is a common neoplasm in humans and etiologic mechanism is not well known, so treatment and evaluation of oral cancer is difficult problem. Traditional TNM classification between prognosis of tumors and classification of histopathologic differentiation has problem like lack of objectivity through operators. In molecular biology, cancer is developed by alteration of activation of oncogene and/or inactivation of tumor suppressor gene. The p53 gene, one of the tumor suppresor genes, is believed to play an important role through mutation and overexpression in the progression of human cancers. The p53 mutation is most frequent genetic disorder in humans. The Cyclin D1 has tumor suppresion activity by regulation of cell cycle. The Cyclin D1 regulate activity of Rb tumor suppresor gene by stimulation of CDK4 The purpose of this study was to observe the expression of p53 protein and Cyclin D1 in oral squamous cell carcinoma, and to get expectation of the malignancy and prognosis of oral squamous cell carcinoma. Using the 15 cases of squamous cell carcinoma and the microscopic H&E and immunohistochemical stain. We divided it into 3 groups according to the stain extent, clinical stage and histologic differentiation. The results were as follows1.In the features of immunohistochemical stain of 15 cases of squamous cell carcinoma, positive reaction of p53 was identified in 8 cases (53.3%) and positive reaction of cyclin D1 was identified in 3 cases (20%). Both positive reaction of p53 protein and Cyclin D1 was show in only one case. 2.8 of p53 positive cases were linked in 87.5% of the end stage tumor, 62.5% of neck node involvement, 87.5% of poorly and moderately histopathplogic differentiation. 3. All 3 of Cyclin D1 positive cases were linked in the end stage tumor, neck node involvement, poorly and moderately histopathologic differentiation. From above results, expression of p53 protein was identified in 53.3% of 15 cases and these results mean oral squamous cell carcinoma was drived by mutation of p53 protein. Especially, highly positive reaction of p53 protein and Cyclin D1 was identified in cases that involvement of neck lymph node and the end stage tumors and it means that the evaluation of p53 protein and Cyclin D1 was useful for evaluation of malignant tumor as specific tumor marker.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.672-683
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• 2004

Background: The treatment results of the advanced lung carcinoma is not satisfactory with the present therapeutic modalities: surgical resection, anti-cancer chemotherapy, and radiotherapy or combination therapy. To predict the prognosis of the non-small-cell lung carcinoma, TNM classification has been was as the basic categorization; however, it has been not satisfactory. It is necessary to consider the causes and the prognosis of the lung carcinoma from another points of view rather the conventional methods. We intended to find out the relationship between the major apoptotic factor, p53 gene and the prognosis of the patient with lung carcinoma. Material and Method: Three hundreds and fifty-nine patients with lung carcinoma who underwent surgery were analysed. We observed p53 protein accumulated in the cellular nuclei. The p53 protein was detected by immuno-histo-chemical method. We collected information of the patient retrospectively. Result: p53 protein densities were observed in 40% in average as a whole. The protein density was 44 percent in man, 25 percent in woman, 49 percent in the squamous cell carcinoma, and 38 percent in the adenocarcinoma. There were significant correlations between the p53 protein density and the mortality in the squamous cell carcinoma (p=0.025), follow-up duration in TNM stage I group (p=0.010), and follow-up duration in the lobectomy patient group (p=0.043), and tumor cell differentiation (p=0.009). p53 protein densities were significantly different between the lobectomy and the pneumonectomy group (p=0.044). Conclusion: The authors found that p53 protein had some correlations with the prognosis of the lung cancer partially in some factors. We suggest the p53 protein density could be used as a marker of prognosis in the non-small-cell lung carcinoma.