• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4315-4320
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• 2012

Background: The P53 tumor suppressor gene plays a pivotal role in maintaining cellular homeostasis by preventing the propagation of genome mutations. P53 in its transcriptionally active form is capable of activating distinct target genes that contribute to either apoptosis or growth arrest, like P21. However, the MDM2 gene is a major negative regulator of P53. Single nucleotide polymorphisms (SNP) in codon Arg72Pro of P53 results in impairment of the tumor suppressor activity of the gene. A similar effect is caused by a SNP in codon 31 of P21. In contrast, a SNP in position 309 of MDM2 results in increased expression due to substitution of thymine by guanine. All three polymorphisms have been associated with increased risk of tumorigenesis. Aim of the study: We aimed to study the prevalence of SNPs in the P53 pathway involving the three genes, P53, P21 and MDM2, among acute myeloid leukemia (AML) patients and to compare it to apparently normal healthy controls for assessment of impact on risk. Results: We found that the P21 ser31arg heterozygous polymorphism increases the risk of AML (P value=0.017, OR=2.946, 95% CI=1.216-7.134). Although the MDM2 309G allele was itself without affect, it showed a synergistic effect with P21 ser/arg polymorphism (P value=0.003, OR=6.807, 95% CI=1.909-24.629). However, the MDM2 309T allele abolish risk effect of the P21 polymorphic allele (P value=0.71). There is no significant association of P53 arg72pro polymorphism on the risk of AML. Conclusion: We suggest that SNPs in the P53 pathway, especially the P21 ser31arg polymorphism and combined polymorphisms especially the P21/MDM2 might be genetic susceptibility factors in the pathogenesis of AML.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.1093-1100
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• 2013

Background: p53 gene variants i.e. 16 bp duplication in intron 3, Arg72Pro in exon 4 and G>A in intron 6 have been reported to modulate susceptibility to various malignancies. Therefore, the present study evaluated the role of these p53 polymorphisms in oral cancer susceptibility in a population from Gujarat, West India. Method: Genotype frequencies at the three p53 loci in 110 controls and 79 oral cancer cases were determined by the PCR-RFLP method. Results: Heterozygous individuals at exon 4 showed protection from developing oral cancer. Homozygous wild and heterozygous individuals at intron 3 and those heterozygous at exon 4 in combination appeared to be at lowered risk. Furthermore, carriers of the 16 bp duplication allele at intron 3, proline allele at exon 4 and G allele at intron 6 were protected from oral cancer development. Conclusion: p53 polymorphisms, especially Arg72Pro in exon 4 could significantly modify the risk of oral cancer development in Gujarat, West Indian population.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2699-2705
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• 2014

This study was to undertaken to investigate the impacts of AhR, CYP1A1, GSTM1 genetic polymorphisms on the R273G mutation in exon 8 of the tumor suppressor p53 gene (TP53) among polycyclic aromatic hydrocarbons (PAHs) exposed to coke-oven workers. One hundred thirteen workers exposed to PAH and 82 control workers were recruited. We genotyped for polymorphisms in the AhR, CYP1A1, GSTM1, and TP53 R273G mutation in blood by PCR methods, and determined the levels of 1-hydroxypyrene as PAH exposure marker in urine using the high pressure liquid chromatography assay. We found that the distribution of alcohol users and the urinary excretion of 1-OHP in the exposed workers were significantly higher than that of the control workers (p=0.004, p<0.001, respectively). Significant differences were observed in the p53 genotype distributions of smoking subjects (p=0.01, 95%CI: 1.23-6.01) and PAH exposure (p=0.008, 95%CI: 1.24-4.48), respectively. Further, significant differences were observed in the p53 exon 8 mutations for the genetic polymorphisms of Lys/Arg for AhR (p=0.02, 95%CI: 0.70-15.86), Val/Val for CYP1A1 (p=0.04, 95%CI: 0.98-19.09) and null for GSTM1 (p=0.02, 95%CI: 1.19-6.26), respectively. Our findings indicated that polymorphisms of PAH metabolic genes, such as AhR, CYP1A1, GSTM1 polymorphisms may interact with p53 genetic variants and may contribute to PAH related cancers.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7413-7417
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• 2014

Background: Development of gastric cancer (GC) is a multistep process that requires alterations in the expression of oncogenes and tumor suppressor genes, occurring over several decades. The p53 tumor suppressor protein is involved in cell-cycle control, apoptosis and DNA repair. One of the most important regulators of p53 is MDM2, which acts as a negative regulator in the p53 pathway. Based on the key role of p53 and MDM2 in tumor suppression, polymorphisms that cause change in their function might affect cancer risk. We therefore elevated associations of the polymorphisms of p53 (R72P) and MDM2 (SNP309) with GC in Iran. Materials and Methods: A total of 104 patients with gastric cancer and 100 controls were recruited. Genomic DNA was extracted from fresh gastric samples. Genotyping of the p53 and MDM2 genes was performed using allele specific PCR (AS-PCR). Results: There was no significant difference between the p53 codon 72 polymorphism distribution in control and patient groups (p=0.54), but the G allele of MDM2 was found to be over-represented in patients (p=0. 01, Odds Ratio=2. 08, 95% Confidence Interval= 1.37-4.34). Conclusions: The p53 R72P seems not to be a potential risk factor for development of GC among Iranian patients, but our data suggest that MDM2 SNP309 might modify the risk related to GC.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4477-4479
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• 2012

Background: The high incidence and relatively good prognosis of breast cancer has made it the most prevalent cancer in the world today. A large number of distinct mutations and polymorphisms in the p53 gene have been reported worldwide, but there is no report regarding the role of this inherited susceptibility gene in breast cancer risk among the Bengalee Hindu Caste females of West Bengal, India. Aim of the Study: We investigated the distribution and the nature of p53 gene mutations and polymorphisms in exons 5-7 in a cohort of 110 Bengalee Hindu breast cancer patients and 127 age, sex and caste matched controls by direct sequencing. Results: We did not observe any mutations and polymorphisms in our studied individuals. Conclusion: We therefore conclude that mutations in exons 5-7 of p53 gene are rare causes of breast cancer among Bengalee Hindu caste females, and therefore of little help for genetic counseling and diagnostic purposes.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.341-346
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• 2013

The risk of cervical cancer development in women infected with HPV varies in relation to the individual host's genetic makeup. Many studies on polymorphisms as genetic factors have been aimed at analyzing associations with cervical cancer. In this study, single nucleotide polymorphisms (SNPs) in 3 genes were investigated in relation to cervical cancer progression in HPV16 infected women with lesions. Two thousand cervical specimens were typed by PCR sequencing methods for TP53 (rs1042522), p16 (rs11515 and rs3088440) and NQO1 (rs1800566). Ninety two HPV16 positive cases and thirty two normal cases were randomly selected. Analysis of TP53 (rs1042522) showed a significantly higher frequency in cancer samples (OR=1.22, 95%CI=1.004-1.481, p-value=0.016) while differences in frequency were not significant within each group (p-value=0.070). The genotype distributions of p16 (rs11515 and rs3088440) and NQO1 (rs1800566) did not show any significantly higher frequency in cancer samples (p-value=0.106, 0.675 and 0.132, respectively) or within each group (p-value=0.347, 0.939 and 0.111, respectively). The results indicated that the polymorphism in TP53 (rs1042522) might be associated with risk of cervical cancer development in HPV16 infected women. Further studies of possible mechanisms of influence on cervical cancer development would be useful to manage HPV infected patients.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8413-8422
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• 2014

Background: To investigate the relationship of five TP53 polymorphisms (p.P47S, p.R72P, PIN3 ins16bp, p.R213R and r.13494g>a) with the esophageal cancer (EC) risk in North Indians. Materials and Methods: Genotyping of p.P47S, p.R72P, PIN3 ins16bp, p.R213R and r.13494g>a polymorphisms of TP53 in 136 sporadic EC patients and 136 controls using polymerase chain reaction and PCR-RFLP. Results: The frequencies of genotype RR, RP and PP of p.R72P polymorphism were 16.91 vs 26.47%, 58.82 vs 49.27% and 24.27 vs 24.27% among patients and controls respectively. We observed significantly increased frequency of RP genotype in cases as compared to controls (OR=1.87, 95% CI, 1.01-3.46, p=0.05). The frequencies of genotype A1A1, A1A2 and A2A2 of PIN3 ins16bp polymorphism were 69.12 vs 70.59%, 27.20 vs 25% and 3.68 vs 4.41% among patients and controls. There was no significant difference among genotype and allele distribution between patients and controls. The frequencies of genotype GG, GA and AA of r.13494g>a polymorphism were 62.50 vs 64.70%, 34.56 vs 30.15% and 2.94 vs 5.15% among patients and controls respectively. No significant difference between genotype and allele frequency was observed in the patients and controls. For p.P47S and p.R213R polymorphisms, all the cases and controls had homozygous wild type genotype. The RP-A1A1-GG genotype combination shows significant risk for EC (OR=2.01, 95%CI: 1.01-3.99, p=0.05). Conclusions: Among the five TP53 polymorphisms investigated, only p.R72P polymorphism may contributes to EC susceptibility.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6871-6879
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• 2014

Background: The purpose of this study was to evaluate the potential association of five (p.P47S, p.R72P, PIN3 Ins16bp, p.R213R and r.13494g>a) polymorphisms of TP53 with the risk of developing breast cancer in North Indian Punjabi population. Methods: We screened DNA samples of 200 sporadic breast cancer patients (197 females and 3 males) and 200 unrelated healthy, gender and age matched individuals for the polymorphisms. Results: For the p.P47S polymorphism, we observed the PP genotype in 99.5% of the patients and PS genotype in only 1 patient. All the controls had the wild type PP genotype. The frequency of RR, RP and PP genotype of p.R72P was 23.5% vs 33.5%, 51.5% vs 45.5% and 25% vs 21% in patients and controls respectively. Heterozygous (RP) genotype was increased in breast cancer patients as compared to controls (51.5 vs 45.5%) and showed 1.61 fold significantly increased risk for breast cancer (OR=1.61, 95% CI, 1.01-2.58, p=0.04). In breast cancer patients the frequencies of A1A1, A1A2 and A2A2 genotypes of PIN3 Ins16bp polymorphism were 67%, 26% and 7% respectively whereas in controls the genotype frequencies were 68.5%, 27.5% and 4% respectively, with no significant difference. For p.R213R (c.639A>G), all individuals had homozygous wild type genotype. The frequencies of GG, GA and AA genotypes of TP53 r.13494g>a polymorphism were 62 vs 67.5%, 33 vs 28% and 5 vs 4.5% in patients and controls respectively, again without significant difference. We observed that RP-A1A1 genotype combination of p.R72P and PIN3 Ins16bp and RP-GG combination of p.R72P and r.13494g>a polymorphism showed significant risk of breast cancer (OR=1.65, 95%CI: 0.98-2.78, p=0.05; OR=1.72, 95%CI: 1.01-2.92, p=0.04). Conclusion: The results of present study indicated that among the five TP53 polymorphisms investigated, the p.R72P polymorphism, and the RP-A1A1 and RP-GG genotype combination contribute to breast cancer susceptibility in North Indians.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1999년도 제51차 추계 학술대회 연제집
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• pp.1-15
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• 1999

In a case-control study to evaluate the factors involved in the development of hepatocellular carcinoma, polymorphisms of the p53 gene were compared in 68 cases mostly infected with hepatitis C virus (HCV) and 68 controls matched for sex and age: DNA from peripheral blood leukocytes was analyzed by the polymerase chain reaction-single strand conformation polymorphism method and direct sequencing. Polymorphisms analyzed were those in exon 4 (CCC vs. CGC, Pro vs. Arg at codon 72, Al allele vs. A2 allele), intron 2 (C vs. G at nucleotide 38, Al vs. A2), intron 3 (C vs. A at nucleotide 65, Al vs. A2; absence and presence of 16 base pair repeat at nucleotides 24 to 39, Al vs. A2), intron 6 (A vs. G at nucleotide 62, Al vs. A2) and intron 7 (C and T vs. T and G at nucleotides 72 and 92, Al vs. A2). A significantly higher frequency of the allele for CCC (Pro, Al) at codon 72 of exon 4 was found in cases (39%) than in controls (26%) (p<0.05). Highly significant linkage of the polymorphisms in exon 4, intron 2, intron 3 and intron 7, and between the intron 3-16 bp duplication and polymorphism in intron 6 also was found. Matched Fair analysis showed significantly higher frequencies of certain haplotypes (1-1-1-1-2-2 or 1-1-2-1-2-1 for exon 4, intron 2, intron 3, the intron 3-16 bp duplication, intron 6 and intron 7) in cases than in controls (p=0.014, OR=2.27, 95% CI= 1.08-5.12). No preference of specific p53 polymorphisms for specific HCV genotype was detected. These findings suggest that in hepatocarcinogenesis mainly due to HCV infection, genetic factors may be involved and that genetic markers can serve as predictors of a high-risk group for hepatocarcinogenesis.

• Tuberculosis and Respiratory Diseases
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• 제44권3호
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• pp.534-546
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• 1997

연구배경 : p53 및 망막모세포 암종(Rb) 항암 유전자는 인체의 여러 임종의 발암 과정에 관련되는 것으로 잘 알려져 있다. 또한 최근에 p53 등의 유전자 다형성이 암 발생에 관여하는 것으로 보고되고 있다. 그러나 Rb 유전자 다형성이 폐암 발생에 영향을 주는지는 아직 보고된 바가 없어 이들 유전자의 다형성의 반도 및 흡연 관련 폐암과 이들 유전자의 다형성과의 관계를 알아보고자 했다. 방 법 : 한국인 폐암 환자 발생의 유전적 감수성을 결정하기 위하여 128명의 폐암 환자군과 145명의 대조군에 대한 p53 유전자(exon 4 및 intron 6 부위) 및 망막모세포 암종(retinoblastoma, Rb) 유전자(intron 17 부위)의 다형성을 분석하였다. p53 유전자의 16bp 반복 다형성을 제외한 유전자 분석은 중합효소연쇄반응-제한효소절편길이 다형현상(PCR-RFLPs)을 이용하였으며, 16bp 반복 다형성은 중합효소연쇄 반응 후 전기영동으로 직접 분석하였다. 결 과 : p53 유전자의 exon 4/AccII 다형성 : 대조군 및 환자군에 대한분석에서 다형적인 3가지 유전자형(Arg/Arg, Arg/Pro, Pro/Pro)이 관찰되었으며, Arg과 Pro 유전자 빈도는 각각 0.66, 0.34 였다. 폐암 환자군에서는 대조군에 비해 Arg/Pro 유전자형은 높고, Pro/Pro 유전자형은 낮게 관찰되었으나 통계적으로 유의하지는 않았다. 조직학적으로 소세포 폐암의 경우 유전자형의 분포가 대조군과 유의한 차이를 보였다. p53 유전자의 intron 3/16bp 중복 다형성 : 대조군과 환자군에서 156bp 동형 접합체와 156bp와 172bp의 이형 접합체만이 관찰되었으며, 172bp 동형 접합체는 관찰되지 않았다. 156bp와 172bp 대립인자 각각 0.98, 0.02로 172bp 대립인자의 빈도가 아주 낮았다. 전반적으로 폐암 환자군과 대조군간의 유전자형 분포에는 유의한 차이가 없었다. p53 유전자의 intron 6/MspI 다형성 : Intron 3의 16bp 중복 다형성과 완전 연관 관계에 있었으며, m1 동형접합체와 m1/m2 이형접합체만 관찰 되었다. 16bp 중복 다형성에서와 같이 m1, m2의 유전인자의 빈도는 각각 0.98, 0.02 으로 MspI 절단부위가 없는 m2 대립인자의 빈도가 아주 낮았다. 전반적으로 폐암환자군과 대조군간의 유전자형 분포에는 유의한 차이가 없었다. Rb 유전자의 intron 17/XbaI 다형성 세가지 다형적인 유전자형(r1/r1, r1/r2, r2/r2)이 관찰 되었으며, 대조군에서 r1, r2의 유전자 빈도는 각각 0.50, 0.50 이었다. 유전자형의 분포가 조직학적으로 흡연관련 폐암군(Kreyberg type I)과 대조군 또는 폐 선암종군 사이에는 통계적으로 유의한 차이를 보였다(p < 0.05). Kreyberg type I군에서는 폐 선암종군에 비해 동행접합체(r2/r2 또는 r1/r1) 빈도가 높고 이형접합체(r1/r2) 빈도는 유의하게 낮은 반면, 선암군에서는 이형접합체 빈도가 73.4%로 특징적으로 높았다. 또한 고흡연자군에서의 유전자형의 비흡연자를 포함한 저흡연자군의 유전자형 분포와 유의한 차이를 보였으며(p = 0.0258), 이형접합체의 빈도가 유의하게 낮게 검출되었다. 따라서 Rb 유전자의 유전자형이 이형접합체인 경우 흡연관련 폐암 발생 위험이 감소되며, 동형접합체일 경우는 상대적으로 발생 위험이 증가되는 것으로 판단된다. 결 론 : 이상의 결과를 종합해보면, p53 유전자의 다형성 보다는 Rb 유전자 다형성이 한국인의 흡연관련 폐암발생의 유전적 감수성 결정에 밀접한 관련이 있을 것으로 사료되며, 앞으로 보다 명확한 연관관계 규명을 위해서는 다른 인종 및 더 많은 수의 환자군에 대한 분석이 요망된다.