• 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 Gastric Cancer
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• v.3 no.4
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• pp.206-213
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• 2003

Purpose: The clinical implication of p53 mutation in gastric cancer is still unclear, as shown by the discordant results that continue to be reported in the literature. Materials and Methods: To assess p53 gene mutation, tumor p53 overexpression, and serum anti-p53 antibody, we employed a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis, an immunohistochemistry using monoclonal antibody DO-7, and an enzymelinked immunosorbent assay (ELISA), respectively. Results: Of 169 surgical specimens of gastric cancer, mutation at exon $5\∼8$ of the p53 was identified in 33 ($19.5\%$) and was significantly correlated with lymph node metastasis. Overexpression of p53 was found in 62 specimens ($36.7\%$) and had a significant correlation with tumor differentiation. Serum anti-p53 antibody was positive in 18 patients ($10.7\%$). Twenty-three of the mutated tumors ($69.7\%$) and 39 of the non-mutated tumors ($28.7\%$) displayed immunoreactivity. Twelve of the immunopositive tumors ($19.4\%$) and 6 of the immunonegative tumors produced anti-p53 antibody. These differences were statistically significant (P<0.001 and P=0.005, respectively). There was no significant difference in survival according to the mutation of p53. Conclusion: Mutation and overexpression of p53 can be easily detected by immunohistochemistry. However, standardization of the immunohistochemical staining method, as well as guidelines for interpreting the stained result, will produce concordant results and thereby improve clinical application.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.151-161
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• 2001

Background: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost. In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. Method: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. Results: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. Conclusion: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.195-198
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• 2002

To identify mutations in exons 5 to 8 of the p53 tumor suppressor gene, we have analysed in 12 spontaneous canine tumors. In a malignant mast cell tumor, a 1 base pair alteration AGT $\longrightarrow$AGC (silent point mutation, serine) in codon 249 in exon 8 was detected. And the mammary gland adenocarcinoma was found to have a mis-sense point mutation (CCT $\longrightarrow$ TCT) in codon 285 in exon 8.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.396-403
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• 2017

Under normal, non-stressed conditions, intracellular p53 is continually ubiquitinated by MDM2 and targeted for degradation. However, in response to severe genotoxic stress, p53 protein levels are markedly increased and apoptotic cell death is triggered. Inhibiting the ubiquitination of p53 under conditions where DNA damage has occurred is therefore crucial for preventing the development of cancer, because if cells with severely damaged genomes are not removed from the population, uncontrolled growth can result. However, questions remain about the cellular mechanisms underlying the regulation of p53 stability. In this study, we show that p53-inducible gene 3 (PIG3), which is a transcriptional target of p53, regulates p53 stability. Overexpression of PIG3 stabilized both endogenous and transfected wild-type p53, whereas a knockdown of PIG3 lead to a reduction in both endogenous and UV-induced p53 levels in p53-proficient human cancer cells. Using both in vivo and in vitro ubiquitination assays, we found that PIG3 suppressed both ubiquitination- and MDM2-dependent proteasomal degradation of p53. Notably, we demonstrate that PIG3 interacts directly with MDM2 and promoted MDM2 ubiquitination. Moreover, elimination of endogenous PIG3 in p53-proficient HCT116 cells decreased p53 phosphorylation in response to UV irradiation. These results suggest an important role for PIG3 in regulating intracellular p53 levels through the inhibition of p53 ubiquitination.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.31-37
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• 1997

Apoptosis is an important event in the anticancer drug therapy. p53 was demonstrated to serve a key component to lead tumor cell death by inducing apoptosis. However, recent study showed the presence of p53 independent apoptotic pathway (Gaftenhaus et al., 1996). We were curious to know it apoptosis induced by adriamycin, a genotoxic anticancer agent, involved p53 gene mutation. Thus this study investigated the p53 gene mutation status among HeLa cell population during apoptosis induced by adriamycin. Under our experimental condition, 12 hour treatment of 1 ${\mu}m$ adriamycin caused apoptosis which was monitored by DNA fragmentation assay. In order to see the p53 gene mutation status, exons of 5, 7 and 8 of p53 gene, where previously reported p53 mutation hot spots reside, were amplified by PCR and nucleotide sequence change was scanned. However, no nucleotide change was observed among apoptotic HeLa cell population. Therefore this study demonstrated that adriamycin induced apoptosis without causing p53 gene damage.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.533-541
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• 1999

Background: Lung cancer in younger patients seems to be a more aggressive disease and their prognosis may be worse than that of older patients. Abnormal p53 expression in primary lung cancer may be an independent prognostic factor for poor prognosis. This study was conducted to determine the difference of abnormal p53 mutation in patients with primary non-small cell lung cancer (NSCLC) under 45 years of age and 55 years old or greater. Method: The present study was performed to compare the clinical and pathological features of primary NSCLC between patients younger than 45 years old and older than 55 years old and to evaluate the difference of abnormal p53 mutation between two groups. Immunohistochemical detection of abnormal p53 mutation was assessed in all primary NSCLC specimens by pathologist. Results: Positive nuclear staining of p53 mutation was found in 76.0% of younger patients and in 76.9% of older patients with variable intensity of staining. And there was no significant correlation between abnormal p53 mutation according to the disease stage or histologic subtype. Conclusion: In this investigation, these were no difference in p53 mutation between two groups.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.6845-6849
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• 2015

Background: Roles of tobacco and alcohol use in etiology of cancer are well established. Alterationin in P53 have essential roles neoplastic change by preventing genome mutation; the aim of this study was to assess the association between P53 mutation and tobacco and alcohol consumption, as well as to assess the epidemiology of tobacco and alcohol use as risk factors for cancer in the adult population of northern Saudi civilians. Materials and Methods: A cross-sectional survey from October 2014 to January 2015, covering 3,398 adults, was performed. P53 mutation molecular detection was performed for 100 tobacco and alcohol users, usingDNA extracted from buccal cells. Results: Of the 3,398 participants 3,253/3398(95.7%) responded, with a male female ratio of 1.10: 1.00. Out of these, 24.8% had smoked tobacco in their lifetime and 2.7% were consumers of alcoholic beverages. None was identified with any P53 mutation. Conclusions: The prevalence of tobacco smoking among the northern Saudi civilians was relatively high. Females' attitudes in tobacco and alcohol related issues were found to be affected by social stigma. Tobacco and alcohol use has no link to P53 gene mutations.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10893-10898
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• 2015

Several molecular markers have been proposed as predictors of outcome in patients with glioblastomas. We investigated the prognostic significance of $O^6$-methylguanine-DNA methyltransferase (MGMT) promoter methylation and TP53 mutation status dependent on isocitrate dehydrogenase 1 (IDH1) mutation in glioblastoma patients. A cohort of 78 patients with histologically confirmed glioblastomas treated with radiation therapy and chemotherapy were reviewed retrospectively. We evaluated the prognostic value of MGMT promoter methylation and TP53 mutation status with regard to progression-free survival (PFS) and overall survival (OS). It was revealed that mutations in IDH1, promoter methylation of MGMT, TP53 mutation, age, Karnofsky performance status (KFS), and extension of resection were independent prognostic factors. In patients with an IDH1 mutation, those with an MGMT methylation were associated with longer PFS (p=0.016) and OS (p=0.013). Nevertheless, the presence of TP53 mutation could stratify the PFS and OS of patients with IDH1 wild type (p=0.003 and 0.029 respectively, log-rank). The MGMT promoter methylation and TP53 mutation were associated with a favorable outcome of patients with and without mutant IDH1, respectively. The results indicate that glioblastomas with MGMT methylation or TP53 mutations have improved survival that may be influenced by IDH1 mutation status.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.93-104
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• 2023

This study aimed to identify new markers that cause lung adenocarcinoma by analyzing mutation hotspots for the top five genes with high mutation frequency in lung adenocarcinoma in Koreans by next generation sequencing (NGS) analysis. The association between TP53 mutation types and patterns with smoking, a major cause of lung cancer, was examined. The clinicopathological characteristics of lung adenocarcinoma patients with TP53 P72R SNPs were analyzed. In Korean lung adenocarcinoma cases, regardless of the smoking status, the TP53 P72R SNP was the most frequently occurring mutational hotspot, in which the nucleotide base was transversed from C to G, and the amino acid was substituted from proline to arginine at codon 72 of TP53. An analysis of the clinicopathological characteristics of lung adenocarcinoma cases with TP53 P72R SNP revealed no significant correlation with the patient's age, gender, smoking status, and tumor differentiation, but a significant correlation with low stage (P-value =0.026). This study confirmed an increase in TP53 rather than EGFR, which was reported as the most frequent mutations in lung adenocarcinoma in Koreans through NGS. Among them, TP53 P72R SNP is the most frequent regardless of smoking status.