• Journal of Gastric Cancer
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• v.3 no.3
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• pp.145-150
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• 2003

Purpose: The p53 tumor suppressor gene is believed to play a pivotal role in preventing the uncontrolled cellular growth characteristic of cancer. Mutation of the p53 gene represent one of the most common genetic alterations in human cancers, and the acquisition of such defects is strongly associated with tumor progression and metastasis. The aim of this study was to evaluate the relation between p53 immunoreactivity and the mutation of p53 gene in gastric adenocarcinoma obtained by laser capture microscope. Materials and Methods: Formalin fixed paraffin embedded tissue specimens were obtained from 20 patients who underwent surgery for gastric cancer. According to UICC TNM system, 3 of the cases were Ia, 2 cases II, 4 cases IIIa, 5 cases IIIb, and 6 cases IV. Results: Immunohistochemical staining revealed eight cases as negative (less than $10\%$), twelve cases as postive (more than $10\%$). The locations of mutations were as follows; 7 cases had point mutation at exon 4, and 3 cases point mutation at exon 8. There was no mutation at exon 5, 6, 7 and 9. The mutation was observed in 1 case out of 8 p53 oncoprotein negative cases, and 7 cases out of 12 p53 positive cases. The mutation was more common in p53 positive cases (P<0.05), However, there was no significant correlation between p53 mutation observed by DNA sequencing after laser capture microdissection and expression of p53 oncoprotein. Conclusion: These result suggest that he expression of p53 oncoprotein not to be related to the mutation of p53 gene at exons 4 through 9 in gastric cancer.

• Journal of Life Science
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• v.24 no.9
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• pp.967-972
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• 2014

In the present study, we prepared eighty-five different kinds of lees extracts and their solvent fractions and investigated their anti-proliferative activities against human colorectal cancer HCT116 cells. HCT116 cells were treated with eighty-five solvent fractions of lees extracts and then cell viability was measured using MTS assay. Among the treated solvent fractions, three solvent fractions (KSD-E1-3, KSD-E2-3, and KSD-E4-3) were selected based on cell viability assay. In addition, we performed an oligo DNA microarray analysis to analyze the gene expression changes by treatment of KSD-E1-3 in HCT116 cells. Among the upregulated genes, we selected 4 genes (NAG-1, ATF3, p21, and DDIT3) and performed RT-PCR using gene-specific primers. Among the treated solvent fractions, KSD-E1-3 dramatically induced the expressions of the four selected genes. In addition, we investigated whether the upregulations of those genes were dependent on the transcription factor p53's presence using p53 null HCT116 cells. The results indicate that the upregulations of NAG-1, ATF3, and DDIT3 are not dependent on the p53 presence, whereas p21 is dependent on the p53 presence. These findings may help to understand the molecular mechanisms of the anti-proliferative activity mediated by rice wine lees in human colorectal cancer cells.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.187-195
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• 1997

Purpose : To analyze the involvement of apoptosis regulatory genes p53, $p21^{wart/cip1}$ bax and bcl-2 in induction of apoptosis by radiation in murine tumors. Materials and methods : The radiation-sensitive ovarian carcinoma OCa-1, and the radiation-resistant hepatocarcinorna HCa-I were used. Tumors, 8 mm in diameter, were irradiated with 25 Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Results : Both tumors were positive for wild-type p53. Radiation inducesd apoptosis in OCa-1 but not in HCa-1. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h In OCa-1 radiation upregulated the expression of p53, $p21^{wart/cip1}$. and the bcl-2/bax ratio was decreased. In HCa-1 radiation increased the expression of both p53 and $p21^{wart/cip1}$, although the increase of the latter was small The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis Conclusions : The development of apoptosis required upregulation of both p53 and $p21^{wart/cip1}$ as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio Prevented apoptosis in the presence of upregulated p53 and $p21^{wart/cip1}$ . These findings indentified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for Predicting the outcome of cancer therapy with cytotoxic agents.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.437-448
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• 2016

Gene set analysis utilizing biologic information is expected to produce more interpretable results because the occurrence of tumors (or diseases) is believed to be associated with the regulation of related genes. Many methods have been developed to identify statistically significant gene sets across different phenotypes; however, most focus exclusively on either the differential gene expression or the differential correlation structure in the gene set. This research provides a new method that simultaneously considers the differential expression of genes and differential coexpression with multiple genes in the gene set. Application of this NEW method is illustrated with real microarray data example, p53; subsequently, a simulation study compares its type I error rate and power with GSEA, SAMGS, GSCA and GSNCA.

• Journal of Life Science
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• v.28 no.4
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• pp.488-495
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• 2018

The p53 gene plays a critical role in the transcriptional regulation of cellular response to stress, DNA damage, hypoxia, and tumor development. Keeping in mind the recently discovered manifold physiological functions of p53, its involvement in the regulation of cancer is not surprising. In about 50% of all human cancers, inactivation of p53's protein function occurs either through mutations in the gene itself or defects in the mechanisms that activate it. This disorder plays a crucial role in tumor evolution by allowing the evasion of a p53-dependent response. Many recent studies have focused on directly targeting p53 mutants by identifying selective, small molecular compounds to deplete them or to restore their tumor-suppressive function. These small molecules should effectively regulate various interactions while maintaining good drug-like properties. Among them, the discovery of the key p53-negative regulator, MDM2, has led to the design of new small molecule inhibitors that block the interaction between p53 and MDM2. Some of these small molecule compounds have now moved from proof-of-concept studies into clinical trials, with prospects for further, more personalized anti-carcinogenic medicines. Here, we review the structural and functional consequences of wild type and mutant p53 as well as the development of therapeutic agents that directly target this gene, and compounds that inhibit the interaction between it and MDM2.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.85-85
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• 1993

The clinical staging system for laryngeal cancers is not sufficient for prognosticator due to different biologic characteristics and their microenvironment according to primary sites. For determining the prognosticators, the authors peformed immunohistochemical staining to EGFR, p53 protein, and pRB in 40 cases of surgically treated squamous cell carcinomas of larynx in our institute during the past 5 years. The results are as followings; 1. The positive expression rate of p53 protein and negative expression rate of pRB showed correlations with clinical parameters. 2. The three-year survival rate for p53 protein positive cases was worse than the p53 protein negative cases. 3. Expression rate of EGFR was not correlated with the clinical parameters. As a conclusion, expression rates of p53 protein and pRB not only reflect well the biologic behavior of laryngeal cancer, but correlate closely with the tumor factors. Therefore they may be useful as the prognosticator to predict the malignant potency of laryngeal squamous cell carcinomas.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.431-438
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• 2006

Purpose : Insulin-like growth factor binding protein(IGFBP)-3 has been known as a tumor suppressor gene, and its anti-tumor function was divided into insulin-like growth factor(IGF)-dependent and IGF-independent mechanism. In IGF-independent mechanism, IGFBP-3 directly interacts with a cell without binding of IGFs, becoming an interesting object in oncology. Several studies demonstrate that one of the well-known tumor suppressor genes, p53, induces directly IGFBP-3 transcription, and the increment of IGFBP-3 expression induces apoptosis of many cancer cells. Recently, the anti-tumor mechanisms of IGFBP-3 have been reported, but post-translational modification of IGFBP-3 and its anti-tumor mechanism are not well known. In this study, we examined whether p53 regulated the glycosylation of IGFBP-3, and analysed the meaning of IGFBP-3 glycosylation related to the apoptosis of cancer cell. Methods : The p53-mutated status of MDA-MB-231 human breast cancer cells was used in this experiment. The expression and glycosylation of IGFBP-3 were tested by Western blot analysis after infection of adenovirus mediated Ad/p53 and/or Ad/IGFBP-3. Results : Ad/p53 infected cells resulted in growth retardation and the induced apoptosis. p53 induced direct expression and glycosylation of IGFBP-3. The increase of glcosylated IGFBP-3 was able to promote cellular apoptosis, and the glycosylation of IGFBP-3 was more activated by the double treatment of Ad/p53 and Ad/IGFBP-3. Conclusion : From this study, the anti-tumor activity of IGFBP-3 was shown to improve the stabilization of IGFBP-3 through the increment of glycosylation of IGFBP-3 by p53. This result suggests that the combined gene therapy of p53 and IGFBP-3 may appropriate treatment of cancer.

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.15-26
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• 1998

p53 is the most frequently mutated gene in female breast cancer tissues and the prognosis of breast cancer could be changed by mutation of the gene. This study was performed to examine risk factors for breast cancer subtypes classified by p53 mutation and to investigate the roles of p53 gene mutation in carcinogenesis of breast cancer. The study subjects were 81 breast cancer patients and 121 controls who were matched to cases 1:1 or 1:2 age, residence, education level and menopausal status. All the subjects were interviewed by a well-trained nurse with standardized questionnaire on reproductive factors, and wire asked to fill the self-administrative food frequency questionnaire. p53 gene mutation in the cancer tissue was screened using polymerase chain reaction (PCR)-single strand conformational polymorphism (SSCP) method. Mutation type was identified by direct sequencing of the exon of which mobility shift was observed in SSCP analysis. Mutations were detected in p53 gene of 25 breast cancer tissues. By direct sequencing, base substitutions were found in 20 cancer tissues (10 transition and 10 transversion), and frame shift mutations in 5 (4 insertions and 1 deletion). For the whole cases and controls, risk of breast cancer incidence decreased when the parity increased, and increased when intake amount of total calory, fat, or protein increased. Eat and protein were statistically significant risk factors for breast cancer with p53 mutation. For breast cancer without p53 mutation, protein intake was the only significant dietary factor. These results suggest that causes of p53 positive breast lancer would be different from those of p53 negative cancer, and that dietary factors or related hormonal factors induce mutation of p53, which may be the first step of breast cancer development or a promoter following some unidentified genetic mutations.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.962-974
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• 1998

Background: Alteration of p53 tumor suppressor genes is most frequently identified in human neoplasms, including lung carcinoma. It is well known that bcl-2 oncoprotein protects cells from apoptosis. Recent studies have demonstrated that bcl-2 expression is associated with favorable prognosis for patients with non-small cell lung carcinoma. However, the precise biologic role of bcl-2 in the development of these tumors is still obscure. p53 and bcl-2 have important regulatory influence in the apoptotic pathway and thus their relationship is of interest in tumorigenesis, especially lung cancer. Purpose: The author investigated to know the prognostic significance of the expression of p53 and bcl-2 in radically resected non-small cell lung cancer. Method: 84 cases of formalin-fixed paraffin-embedded blocks from resected primary non-small cell lung cancer from 1980 to 1994 at Hanyang University Hospital were available for both clinical follow-up and immunohistochemical staining using monoclonal antibodies for p53 and bcl-2. Results : The histologic classification of the tumor was based on WHO criteria., and the specimens included 45 squamous cell carcinomas(53.6%), 28 adeonocarcinomas(33.3%) and 11 large cell carcinomas(13.1 %). p53 immunoreactivity was noted in 47 cases of 84 cases(56.0%). bcl-2 immunoreactivity was noted in 15 cases of 84 cases(17.9%). The mean survival duration was $64.23{\pm}10.73$ months in bcl-2 positive group and $35.28{\pm}4$. 39 months in bcl-2 negative group. The bcl-2 expression was significantly correlated with survival in radically resected non-small cell lung cancer patients(p=0.03). The mean survival duration was $34.71{\pm}6.12$ months in p53 positive group and $45.35{\pm}6.30$ months in p53 negative group(p=0.21). The p53 expression was not predictive for survival. There was no correlation between combination of the different status of p53 and bcl-2 expression in our study. Conclusions : The interaction and the regulation of new biologic markers, such as those involved in the apoptotic pathway, are complex. bcl-2 overexpression is a good prognostic factor in non-small cell lung cancer and p53 expression is not significantly associated with the prognostic factor in non-small cell lung cancer.

• Journal of the Korean Chemical Society
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• v.48 no.1
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• pp.33-38
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• 2004

Mutation of p53 tumor suppressor gene in HNSCC (head and neck squamous cell carcinoma) has been proposed high rate. We extracted genomic DNA from 50 head and neck cancer. The DNA was amplified by PCR at exon 5-8 in p53 tumor suppressor gene. We have compared single strand conformation polymorphism (SSCP) and denaturing high performance liquid chromatography (DHPLC) method for analysis of p53 somatic mutation. As a result, 16 deleted mutations (32%) were detected by SSCP analysis and 17 deleted mutations (34%) were detected by DHPLC analysis at exon 8. All of 17 mutations were proved by sequencing. We conclude that DHPLC is a fast and simple screening method rather than SSCP analysis.