• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권5호
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• pp.373-384
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• 2001

Cellular proliferation is an intricately regulated process mediated by the coordinated interactions of critical growth control genes. Two of these factors in mammalian cells are the p53 and mdm-2 genes. A protein product of the mem-2 oncogene has been recently shown to associate with the protein encoded by the tumor suppressor gene p53. The p53 tumor suppressor protein is stabilized in response to DNA damage and other stress signals and causes the cell to undergo growth arrest or apoptosis, thus preventing the establishment of mutations in future cellular generations. Mutation or loss of p53 is a very common event in tumor progression. It occurs in about 50% of all tumors analysed including of colon, lung, breast and liver. The cellular mdm-2 gene, which has potential transforming activity that can be activated by overexpression, is amplified in a significant percentage of human sarcoma and in other mammalian tumors. Proteins encoded by the mdm-2 gene are able to bind to the p53 protein and, when overexpressed, can inhibit p53's transcriptional activation function, thus mdm-2 can act as a negative regulator of p53 function. Experimental study was performed to observe the relationship between p53 gene mutation and mdm-2 protein expression and apply the results to the clinical activity. 36 golden syrian hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek(control side) was treated with mineral oil as the same manner to the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were examined for histology and immunohistochemistry observation, and were completely dissected by microdissection and DNA from both tissue were isolated by proteins K/phenol/chloroform extraction. Segments of the hamster p53 exons 5, 6, 7 and 8 were amplified by PCR using the oligonucleotide primers, and then confirmational change was observed by SSCP respectively. The results were as follows : 1. Dysplasia at 6 weeks, carcinoma in situ at 8 weeks and invasive carcinoma from 10 weeks could be observed in experimental groups. 2. p53 mutations were detected in 10 of the 36(28%) and the exons 6(6 of the 10 : 60%) was the most hot spot area among the highy conserved region(exons 5, 6, 7 & 8). 3. Immunohistochemical study confirmed 22 of the 36(61%) of p53 expression involving 10 of p53 mutations. 4. mdm-2 expression of was showed in 3 of the 36(8%) involving 1 of the 22 of p53 expression and 2 of the 14 of p53 non-expression. From the above results, mutation of p53 gene or expression of p53 protein may have the influence of the DMBA induced carcinoma of hamster buccal pouch but the expression of mdm-2 protein may not have relationship with tumorigenesis.

• International Journal of Oral Biology
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• 제32권2호
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• pp.79-84
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• 2007

Oral squamous carcinoma (OSC) is the most common malignant neoplasm of the oral mucosa. Although the etiology of OSC is not fully understood, accumulated evidences indicate that the activation of proto-oncogenes and the inactivation of tumor suppressor genes underlie the disease development. An OSC cell line, YD-9 was newly established and characterized. However, the mutational analysis of p53 gene was not performed. Thus, in this study, the presence of mutation in the p53 gene was examined by amplification of exon-4 to -8 and subsequent DNA sequencing. Two point mutations were found in exon-4 and -6: A to G, resulting in amino acid change Tyr to Cys in exon-4, and C to G, resulting in amino acid change Gly to Arg in exon-6, respectively. Any mutation was not found in the exon-5, -7 and -8. The presented results would contribute to basic research to understand the biological mechanism of OSC using YD-9 cells.

• 한국동물학회지
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• 제39권3호
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• pp.231-238
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• 1996

여러 종류의 폐암과 췌장암 세포주를 배양하여 DNA를 분리하였다. 분리한 DNA는 PCR(Polymerase Chain Reaction)로 증폭하여 염기 서열화를 시행하여 K-ras와 p53 유전자들의 돌연변이 종류. 빈도 및 가능한 관계에 대하여 조사하였다. 연구한 암세포주 중 약 81%가 종양 유전자 K-ras와 암 억제 유전자 p53 중 적어도 하나의 돌연변이를 가지고 있었으며 두 유전자 각각에 대해서는 암 세포주 중 약 54.5%에서 돌연변이가 나타났다. 발견된 돌연변이의 종류는 1개의 세포주에 발견된 넌센스 돌연변이 이외에는 모두 미스센스 돌연변이가 일어났으며 2개의 세포주에서 일어난 염기 삽입이외에는 모두 염기 치환이 일어났다. 현재까지 p53 코돈 중 ras와 동시에 돌연변이가 일어난다고 보고된 코돈 이외에도 p53 코돈 164-165과 248이 K-ras와 동시에 돌연변이가 발생하였고, p53 유전자의 돌연변이의 위치에 관계없이 K-ras 유전자에서는 exon 1. 코돈 12개에서 돌연변이가 발생하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3503-3507
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• 2013

Background: Although the majority of investigations concerned with TP53 and its protein have focused on coding regions, recently a set of studies highlighted significant roles of regulatory elements located in p53 mRNA, especially 5'UTR. The wrap53${\alpha}$ transcript is one of those that acts as a natural antisense agent, forming RNA-RNA hybrids with p53 mRNA and protecting it from degradation. Materials and Methods: In this study, we focused on the mutation status of exon $1{\alpha}$ of the WRAP53 gene (according to exon 1 of p53) in 160 breast tumor tissue samples and conducted a bioinformatics search for probable miRNA binding site in the p53/wrap53 overlapping region. Mutations were detected, using single stranded conformation polymorphism (SSCP) and sequencing. We applied the miRBase database for prediction of miRNAs which target overlapping region of p53/wrap53 transcripts. Results: Our results showed all samples to have wild type alleles in exon 1 of TP53 gene. We could detect a novel and unreported intronic mutation (IVS1+56, G>C) outside overlapping regions of p53/wrap53 genes in breast cancer tissues and also predict the presence of a binding site for miR-4732-5p in the 5'UTR of Wrap53 mRNA. Conclusions: From our findings we propose designing further studies focused on overexpression of miRNA-4732-5p and introducing different mutations in the overlapping region of wrap53 and p53 genes in order to study their effects on p53 and its ${\Delta}N$ isoform (${\Delta}$40p53) expression. The results may provide new pieces in the p53 targeting puzzle for cancer therapy.

• 대한골관절종양학회지
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• 제6권4호
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• pp.143-151
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• 2000

목적 : p53 종양억제 유전자는 사람의 암에서 변형이 가장 많이 발견되는 유전자로 유잉 육종에서 p53 유전자의 변형을 관찰하고자 하였다. 재료 및 방법 : 유잉육종 환자 35례의 파라핀 블록을 사용하였으며, 유전자의 결핍과 p53 유전자의 염기서열의 변형을 관찰하였다. 결과 : 정성적인 중합효소 연쇄반응을 이용한 p53의 4-9번까지의 유전자검사중 2례에서 동일성의 유전자 결핍이 관찰되었으며, exon 5-8의 유전자 중합효소 연쇄반응에서는 3례에서 missense 점돌연변이가 관찰되었다. 결론 : 이상의 결과로 p53은 유전적으로 적은 부분에서 유잉육종에 관여하는 것으로 관찰 되었다.

• Tuberculosis and Respiratory Diseases
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• 제49권4호
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• pp.453-465
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• 2000

연구배경 : 폐암의 발생과정은 다양한 유전자 이상과 여러 가지경로 이상을 포함한 다단계 과정이다. 암유전자의 활성화나 종양억제유전자의 불활성화, 그리고 결과적인 유전적 불안정성의 증가는 폐암의 발암과정에서 일어나는 주요한 사건이며 임상적으로 폐암이 진단되기까지 10내지 20여 가지의 유전적 변화가 축적되는 것으로 알려져 있다. 본 연구에서 저자들은 비소세포폐암에서 종양억제유전자인 p53과 FHIT의 돌연변이, FHIT 유전자의 전사체 이상 여부를 확인하고 종양억제유전자부근에 위치하는 극소위성의 유전적 변화를 관찰하였다. 대상 및 방법 : 비소세포폐암으로 진단된 후 외과적 적출술을 시행받은 환자 29명의 생검조직과 그에 대응하는 동일인의 정상조직을 대상으로 하였다. p53과 FHIT의 돌연변이 여부는 PCR-SSCP, DNA 염기분석으로 확인하였고 D3S1285, D9S171, TP53에서 극소위성 불안정성과 이형접합성 상실은 PCR로 확인하였다. FHIT 유전자의 전사체 이상 여부 확인을 위해서는 RT-PCR을 사용하였다. 결과 : 1) p53 유전자의 2예에서 관찰되었고 모두 exon 5에서 1개의 염기가 치환되는 점돌연변이였다. 2) 극소위성 불안정성은 D3S1285와 D9S171에서 각각 2예, 1예, 이형접합성 상실은 D3S1285, D9S171, TP53에서 각각 3예, 4예, 7예가 관찰되었다. 3) FHIT 유전자의 변이는 11예에서 관찰되었으며 이중 6예는 exon 8의 codon 98에서 염기서열이 CAT가 CAC로 바뀌는 잠재적 치환이었다. 4) FHIT 유전자의 전사체 이상은 $\beta$-actin이 제대로 발현되는 15예중 4예에서 관찰되었으며 exon 6-9의 결실로 확인되었다. 결론 : 이상으로 비소세포폐암 발생에 p53, FHIT 유전자의 변이, 극소위성 불안정성과 이형접합성 상실 등 다양한 분자유전학적 기전이 복합적으로 작용할 것으로 생각되며 이번 연구에서 조사된 유전적 이상의 빈도는 앞서 발표된 서양의 연구결과와 대체적으로 일치한다. 특히 극소위성의 분석은 편평세포암에서 종양표지자로서의 역할이 기대된다. 이런 발암과정에 대한 이해는 예방, 진단 및 치료적 접근을 발전시키는데 도움을 줄 수 있을 것이고 향후 이들에 관한 가능적 연구들이 수행되어야 할 것이다.

• Journal of Chest Surgery
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• 제38권12호
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• pp.835-843
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• 2005

배경: 분자학적 표지자들과 식도암과의 관련성에 대해서 아직 뚜렷하게 밝혀진 바가 없다. 본 연구에서는 먼저 p53, Cyclin D1과 Ki67 지수 등 종양 표식자가 국내 식도암 환자에서 수술 후 얻어진 식도암 조직의 병기, 악성도, 임파선 전이 여부 등과 어떠한 관련성이 있는가를 알아보고 이를 이용해 향후 국내 식도암 환자에 대한 예후 분석 및 치료방침 결정 그리고 조기발견에 이용할 수 있는지 알아보았다. 또한 본 연구는 분자학적 표지자들의 임상적용의 기초를 마련하고자 하는 목적으로 시행하였다. 대상 및 방법: 1992년 3월부터 수술 후 조직절편이 보존된 124명의 환자를 대상으로 하였다. 조직절편의 파라핀을 제거한 뒤에 p53 변이, Cyclin D1의 과발현, Ki67 지수에 대한 면역조직화학 염색법을 시행하였으며 조직슬라이드상에서 세포분열지수를 구하였다. 이 결과와 임상적인 변수들과의 상관관계를 분석하였고, 환자의 생존 및 재발 결과와 비교하였다. 결과: 환자의 성별, 나이, 병기, 종양 크기, 타장기 전이 여부, 국소적인 재발 여부와 p53의 변이, Cyclin D1의 과발현, Ki67 지수, 세포분열 지수에 따른 통계적으로 유의한 차이는 없었다. Ki67 지수는 40 미만인 경우와 40 이상인 경우로 나누었을 경우 통계적으로 유의하게 생존기간에 있어서 차이가 나는 것으로 나타났으나(p=0.011) 다른 표지자들은 생존기간에 유의한 차이를 보이지 않았다. 결론: 높은 Ki67지수는 식도의 편평상피암의 예후에 나쁜 영향을 미치는 것으로 나타났으나 다른 표지자들은 영향을 미치지 않았다 이번의 연구를 통해 분자학적인 지표들이 임상적으로 가치 있는 인자가 될 수 있다고 판단되었다.

• BMB Reports
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• 제29권1호
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• pp.88-91
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• 1996

The anaerobically expressed gene aeg-46.5, which had been identified by the operon fusion technique with a hybrid bacteriophage of ${\lambda}$ and Mu, ${\lambda}$placMu53, was studied for its expression pattern and growth. The expression of aeg-46.5 was studied in the wild-type cell and mutant cells that have mutation (s) in the control gene of anaerobic respiration (fnr) and nitrate response (narL and narP). The ${\beta}$-galactosidase reporter gene showed maximum expression in narL host after two hours of aerobic to anaerobic switch in M9-Glc-nitrate medium. Both 40 mM and 100 mM concentrations of nitrate ion in the medium had little effect on expression level. We propose that aeg-46.5 is subject to multiple regulations of anaerobic activation by Fnr, nitrate activation by NarP and repression mediated by NarL.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9603-9606
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• 2014

Background: Endometrial cancer is the fourth most common cancer among women in developed countries. Patients with endometrial cancer may benefit from systemic chemotherapy alone or in combination with targeted therapies if the disease is clinically diagnosed prior to spread and metastasis to other organs. The aim of this study was to evaluate the prognostic role of p53 polymorphism and its correlation with tumor grade in human uterine endometrial carcinomas. Materials and Methods: A total of 75 patients with endometrial carcinomas were studied for possible mutations in exon 4 of the p53 gene using polymerase chain reaction and restricting fragment length polymorphism techniques and sequencing. Results: In recent study, The rate of homozygote genotype of pro/pro or Arg/Arg in high grade group was higher than in comparison with low grade one. In addition samples that were undigested in RFLP, showed mutation in exone 4. Conclusions: Our findings showed that high grade endometrial carcinomas are highly associated with TP53 polymorphisms in comparison with low grades.

• 대한기관식도과학회지
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• 제9권2호
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• pp.36-43
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• 2003

Background and objectives; Esophageal cancer is one of the most malignant tumors and has a poor prognosis. Many clinical studies have been tried for improving prognosis of esophageal cancer. Some clinical studies used molecular markers as the predictor of prognosis & the indicator for the choice of multimodality treatments. We investigated the relationship between some molecular markers, including p53 mutation, expression of bc12, Ki67 index, expression of E-Cadherin and the prognosis of esophageal cancer, Materials and Method; The materials used in this study were the tumor specimens from 72 esophageal cancer patients who underwent esophagectomy from 1987 to 2002 in our institute. The mutation of p53, expression of bc12, Ki67 index, and expression of E-cadherin were examined by using the tissue array and immunohistochemical staining method. The patients were subgrouped into higher Ki67 index group if the index was higher than 30. The patients were also subgrouped into grade 1(>90%), grade 2(50∼90%), grade 3 (10∼50%), and grade 4(<10%) according to the rate of E-Cadherin expression. We studied the relationship between the rates of immunohistochemical staining and the survival rate. Results: Seventy two tumor specimens from 72 patients were studied. (mean age ; 59.6 years, male female = 69 : 3) The histologic type of the specimens was all squamous cell carcinoma. The patient's number of stage IIA, IIB, and Ⅳ was 30, 37, and 7 respectively, Thirty patients were alive and overall 5 year-survival rate was 28%. The mutation of p53 was shown in 54.2% of the patients. Five year survival rates of negative and positive groups were 29% and 28% respectively.(p=0.4) Expression of bc12 gene was found in 13.9% of the specimens. Five year survival rates of negative and positive groups were 30% and 21%.(p=0.3) Higher Ki67 index was correlated to poorer differentiation.(p=0.05) Five year survival rates of higher and lower groups of Ki67 index were 47% and 30%.(p=0.15) Higher expression rate of E-Cadherin showed better differentiation.(p=0.04). However we couldn't find any survival differences between these 4 groups.(p=0.23) Conclusion; We could not find any molecular markers meaningful in the prognosis of esophageal cancer patients. We just found the tumor markers correlated to the differentiation of esophageal cancer. However, we knew that we need further study with some more samples to stratify other important prognostic factors of esophageal cancer.