• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8239-8245
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• 2016

The p53 gene is inactivated by the human papillomavirus (HPV) E6 protein in the majority of cervical cancers. Treatment of HeLa S3 cells with siRNA for HPV E6 permitted adenovirus-mediated transduction of a p53 gene linked to an upstream estrogen response element (ERE). Our previous study in non-siRNA treated HHUA cells, which are derived from an endometrial cancer and express estrogen receptor ${\beta}$, showed enhancing effects of an upstream ERE on adenovirus-mediated p53 gene transduction. In HeLa S3 cells treated with siRNA for HPV E6, adenovirus-mediated transduction was enhanced by an upstream ERE linked to a p53 gene carrying a proline variant at codon 72, but not for a p53 gene with arginine variant at codon 72. Expression levels of p53 mRNA and Coxsackie/adenovirus receptor (CAR) mRNA after adenovirus-mediated transfer of an ERE-linked p53 gene (proline variant at codon 72) were higher compared with those after non-ERE-linked p53 gene transfer in siRNA-treated HeLa S3 cells. Western blot analysis showed lower ${\beta}$-tubulin levels and comparatively higher p53/${\beta}$-tubulin or CAR/${\beta}$-tubulin ratios in siRNA-treated HeLa S3 cells after adenovirus-mediated ERE-linked p53 gene (proline variant at codon 72) transfer compared with those in non-siRNA-treated cells. Apoptosis, as measured by annexin V binding, was higher after adenovirus-mediated ERE-linked p53 gene (proline variant at codon 72) transfer compared with that after non-ERE-linked p53 gene transfer in siRNA-treated cells.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.67-75
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• 2001

Background : Two tumor suppressor genes, p53 and p16, which have different roles in controlling the cell cycle and inducing apoptosis, are frequently inactivated during carcinogenesis including lung cancer. Single tumor suppressor gene therapies using either with p53 or p16 have been studied extensively. However, there is a paucity of reports regarding a combined gene therapy using these two genes. Methods : The combined effect of p53 and p16 gene transfer by the adenoviral vector on the growth of lung cancer cell lines and its interactive mechanism was investigated. Results : An isobologram showed that the co-transduction of p53 and p16 exhibited a synergistic growth in hibitory effect on NCI H358 and an additive effect on NCI H23. Cell cycle analysis demonstrated the induction of a synergistic G1/S arrest by a combined p53 and p16 transfer. This synergistic interaction was again confirmed in a soft agar confirmed in a soft agar clonogenic assay. Conclusion : These observations suggest the potential of a p53 and p16 combination gene therapy as another potent strategy in cancer gene therapy.

• 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 Korean Neurosurgical Society
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• v.37 no.1
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• pp.48-53
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• 2005

Objective: The purpose of this study is to elucidate in vitro responses to combined gamma knife irradiation and p53 gene transfection on human malignant glioma cell lines. Methods: Two malignant human glioma cell lines, U87MG (p53-wild type) and U373MG (p53-mutant) were transfected with an adenoviral vector containing p53 (MOI of 50) before and after applying 20Gy of gamma irradiation. Various assessments were performed, including, cell viability by MTT assay; apoptosis by annexin assay; and cell cycle by flow cytometry, for the seven groups: mock, p53 only, gamma knife (GK) only, GK after LacZ, LacZ after GK, GK after p53, p53 after GK. Results: Cell survival decreased especially, in the subgroup transfected with p53 after gamma irradiation. Apoptosis tended to increase in p53 transfected U373 MG after gamma irradiation (apoptotic rate, 38.9%). The G2-M phase cell cycle arrest markedly increased by transfecting with p53, 48 hours after gamma knife irradiation in U373 MG (G2-M phase, 90.8%). Conclusion: These results suggest that the in vitro effects of combined gamma knife irradiation and p53 gene transfection is an augmentation of apoptosis and G2-M phase cell cycle arrest, which are more exaggerated in U373 MG with p53 transfection after gamma knife irradiation.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.261-266
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• 2004

Although significant progress has been made in the surgical treatment of esophageal carcinoma as well as in the detection of early stage esophageal carcinoma by diagnostic techniques, the prognosis of the esophageal carcinoma patients remain poor. The p53 gene product is known to regulate cell growth and proliferation. And the nm23 gene was identified originally as an anti-metastatic influence whose expression was correlated inversely with tumor metastatic potential in murine melanoma cell lines. This experiment was intended to know the relationship among the p53 and nm23 gene expression versus clinicopahologic characteristics of the esophageal cancer. Total 40 cases were collected from patients who had undergone esophagectomy at St. Mary's Hospital, Catholic university of Korea. Immunohistochemical stain for p53 mutant-type protein and nm23 protein was graded as <10% positive tumor cells: negative; 10∼30% positive tumor cells: ＋ ; 30∼50% positive tumor cells: ＋＋, and >50% positive tumor cells: ＋＋＋. The tumor invasion was grades as none:－ ; mild:＋ ; moderate:＋＋ ; severe: ＋＋＋. Overexpression of p53 protein and nm23 was not associated with the survival and cliniocopathologic characteristics of the esophageal cancer. Moreover, the combination analysis of p53 and nm23 revealed that there was no relationship between the gene expression and the clinicopatholic characteristics of the esophageal cancer.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.279-285
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• 1993

Alterations of the p53 gene arc among the most frequent genetic changes in human cancer and often result in increased levels of p53 protein within the malignant cells. Detection of accumulated p53 protein can be a useful prognostic tool in human cancer. In order to make polyclonal antibodies for immunohistochemical screening. human p53 gene was expressed in E. coli in the form of GST (glutathione S-transfi.:rase) fusion proteins. Two p53 gene fragments. which were N('()I small fragment encoding amino acid residues of 1-151-: and Ncol large fragment of 159-393. were subeloned into the unique BamHI site present within the pGEX-2T vector using BamHI linker and recombinant plasmids pGTNS and pGTNL were constructed. respectively. The p53 cDNA fragment (from pC53-$SN_3$,) encoding amino acid 38-145 (proline at residue 72) was amplified by polymerase chain reaction(PCR). The amplified DNA was digested with BamHI and Prull and inserted into the BamHI-Smal sites of pG EX-2T and recombinant plasmid pGTBP was constructed. After IPTG induction of these plasmids for 4 hours. fusion proteins were purified from E. coli extracts with glutathione Sepharose beads. The bound proteins were resolved by 10% SDS-polyacrylamide gel electrophoresis and the molecular weights were 54 kDa. 53 kDa and 40 kDa. respectively. Approximately one milligram of fusion proteins were purified from 1 -liter cultures.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6739-6742
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• 2013

Background: Breast cancer is a major health problem worldwide. Olive oil induces apoptosis in some cancer cells due to phenolic compounds like oleuropein. Although oleuropein has anticancer activity, the underlying mechanisms of action remain unknown. The study aimed to assess the mechanism of oleuropin-induced breast cancer cell apoptosis. Materials and Methods: p53, Bcl-2 and Bax gene expression was evaluated by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in luminal MCF-7 cells. Results: Oleuropein-induced apoptosis was accompanied by up-regulation of both p53 and Bax gene expression levels and down-regulation in Bcl2. Conclusions: Oleuropein induces apoptosis in breast tumour cells via a p53-dependent pathway mediated by Bax and Bcl2 genes. Therefore, oleuropein may have therapeutic potential in breast cancer patients by inducing apoptosis via activation of the p53 pathway.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.653-658
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• 1993

Background: Recent advancement of molecular genetics has revealed that malignant transformation of a cell may be a complex multistep process and this process is grouped, in general, into two distinct categories, activation of protooncogenes and inactivation of tumor suppressor genes. This study was focused on the mutation of p53 tumor suppressor gene, because p53 gene mutation is now generally accepted to be one of the most frequent genetic changes in a variety of human cancers. Although lung cancer is one of the common cancers in Korea, the genetic change in the carcinogenesis process is not yet known clearly. To investigate the role of p53 gene mutation in lung cancer, we examined the mutations of exon 4-8 of the p53 gene in humna lung cancer cell lines, because most of the mutations of p53 gene have been reported to develop in exon 4-8. Method: Genomic DNA was obtained by the digestion of proteinase K and the extraction by phenol-chloroform-ethanol method from two human pulmonary adenocarcinoma cell lines, PC-9 and PC-14, and one human small cell lung cancer cell line, H69. To detect the mutations of exon 4-8 of the p53 gene, polymerase chain reaction single-strand conformation polymorphism(PCR-SSCP) analysis was performed with the DNA extracted from the cells. Results: The mutation of p53 gene was present in all three cell lines tested. In PC-9, PC-14 and H69, the altered mobility was detected in exon 7, 7 and 5, respectively. Conclusion: These results suggest that p53 gene mutation plays an important role in certain steps of the carcinogenesis of human non-small cell and small cell lung cancer.