• Title/Summary/Keyword: gene mutations

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The Overexpression of p53 in Head and Neck Squamous Cell Carcinoma as Prognostic Marker (두경부 편평 세포암에서 예후인자로서의 p53 발현)

  • Jeong Seung-Won;Lee Hyung-Seok;Park Chul-Won;Park Yong-Wook;Park Chan-Keum;Jang Se-Jin;Tae Kyung
    • Korean Journal of Head & Neck Oncology
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    • v.17 no.2
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    • pp.169-173
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    • 2001
  • Objectives: The p53 tumor suppressor gene encodes a nuclear transcription factor that is critical regulator of cell growth and proliferation through its action in cell-cycle checkpoint control. The wide variety of stressful stmuli which include DNA damage, hypoxia, heat shock, metabolic changes activate the p53 protein, which in turn drives a series of events that culminate either in cell cycle arrest or apoptosis. Mutations of the p53 gene is the most common genetic alteration in human cancer. This gene is altered in approximately 40-60% of head and neck cancers. Whereas the wild-type form of the p53 protein plays a central role in cell-cycle control in response to DNA damage, most of the mutant forms are unable to do so. The high levels of p53 protein expression in tissues are related to the increased cellular proliferative activity and may be associated with the poor clinical outcome. To determine whether the expression of the p53 protein has prognostic significance and is associated with patterns of treatment failure in head and neck squamous cell carcinoma (HNSCC), We analyzed p53 overexpression in 40 cases of HNSCC. Materials and Methods: Immunohistochemical analysis with a monoclonal antibody (DO7) specific for p53 protein was used to detect expression of the protein in formalin-fixed, paraffin-embedded tumor samples from 40 HNSCC. We evaluated p53 protein expression and analyzed the relationship between the p53 overexpression and age, sex, primary tumor site, stage, survival rate, recurrence. All reported P values resulted from two-sided statistical tests. Results: Overexpression of p53 was detected in 20 cases(50%) among 40 cases of HNSCC. The p53 overexpression was not associated with age, sex, primary tumor site, stage, recurrence and survival rate. Conclusions: In our results, p53 was not significant prognostic factor in HNSCC. Based on many previous studies, It is evident that p53 has a certain role in tumorigenesis of HNSCC. So, the further study is needed to evaluate the prognostic significance of p53 in HNSCC.

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Correlation between Cyclin D1, p53, Bcl-2 Protein Expression and Prognosis in Primary, Resected Stage IIIA Non-Small Cell Lung Cancer (NSCLC) (완전 절제된 제IIIA기 비소세포폐암에서 Cyclin D1, p53, Bcl-2 단백질 발현의 의의)

  • 정경영;양우익
    • Journal of Chest Surgery
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    • v.31 no.12
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    • pp.1200-1205
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    • 1998
  • Background: Lung cancer formation is a multistage process involving activation of protooncogene and inactivation of tumor suppressor genes. We evaluate the significance of cyclin D1, p53, bcl-2 gene mutations in patients with curatively resected stage IIIA non-small cell lung cancer(NSCLC). Material and Method: One hundred consecutive cases of stage IIIA lung cancers from patients operated on curatvely between 1990 and 1995 for which adequate paraffin blocks and clinical history were available. Immunohistochemical studies were performed on the representative tissue sections from each case by the labelled streptovidin- biotin method. Sections for cyclin D1, p53, Bcl-2 immunostaining were pretreated in a microwave oven for 10 to 20 minutes in citrate buffer before immunostaining. The overnight incubation with NCL-cyclin D1-GM for cyclin D1, with clone DO-7 for p53, with clone 124 for bcl-2 was done. Mean follow-up was 24.1 months (range 2-84 months) after operation. Result: One hundred cases of lung cancers were composed of 56 cases of squamous cell carcinoma, 37 cases of adenocarcinoma, 5 cases of adenosquamous cell carcinoma, and 2 cases of large cell carcinoma. The 5-year survival was 32.1%. The positive expression rate of cyclin D1 was 35%, p53 was 56%, and bcl-2 was 17%. But there were no correlation between cyclin D1, p53, Bcl-2 protein expression and survival. Conclusion: These observation indicate that cyclin D1, p53, bcl-2 protein overexpression might be implicated in the oncogenesis of non-small cell lung carcinomas but they have no usefulness as a prognostic marker.

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BRCA1 and TP53 Gene-Mutations: Family Predisposition and Radioecological Risk of Developing Breast Cancer

  • Apsalikov, Bakytbek;Manambaeva, Zukhra;Ospanov, Erlan;Massabayeva, Meruyert;Zhabagin, Kuantkan;Zhagiparova, Zhanar;Maximov, Vladymir;Voropaeva, Elena;Apsalikov, Kazbek;Belikhina, Tatiana;Abdrahmanov, Ramil;Cherepkova, Elena;Tanatarov, Sayat;Massadykov, Adilzhan;Urazalina, Naylia
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.4059-4062
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    • 2016
  • Frequencies of polymorphisms of genes BRCA1 and ТР53 in breast cancer (BC) patients with a BC family history and radiation history were assessed and compared in the Semey region of Kazakhstan. The study included 60 women directly irradiated by the activities of the Semipalatinsk test site with a calculated effective equivalent dose of 500 mSv and their first generation descendants (group BC+Her+Exp); 65 women with family BC and absence of radiological history - the effective equivalent dose due to anthropogenic sources not exceeding 50 mSv (group BC+Her-Exp). The comparison group consisted of 65 women patients with breast cancer without family and radiological history (BC-Her-Exp). The control group comprised 60 women without breast cancer and without family and radiological history (nonBC). We carried out the genotyping of the polymorphisms c.2311T>C, c.4308T>C and 5382insC of the BRCA1 gene and rs1042522 of the ТР53 gene. The frequency of the polymorphism c.2311T>C was significantly higher in patients of the group BC+Her+Exp than in healthy women, and of the polymorphism 5382insC in BC+Her+Exp compared to all other groups. The frequency of the rs1042522 polymorphism of ТР53 was significantly higher in all groups of patients with breast cancer compared with the control group. Differences between groups of women with breast cancer were significant only in BC+Her+Exp vs. BC+Her-Exp. Combinations of polymorphisms of the genes BRCA1 and TP53 predominated in women with a family and radiological history.

The Structural and Functional Role of p53 as a Cancer Therapeutic Target (암 치료 표적으로서 p53의 구조적 및 기능적 역할)

  • Han, Chang Woo;Park, So Young;Jeong, Mi Suk;Jang, Se Bok
    • 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.

Clinical Features and Genetic Analysis of Homocystinuria Patients in Korea (전형적 호모시스틴뇨증 환자들의 임상적 특성과 유전자분석)

  • Lee, Yena;Lee, Jeongho;Lee, Dong Hwan
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.15 no.2
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    • pp.78-86
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    • 2015
  • Purpose: Homocystinuria (OMIM#236200) is a metabolic disease caused by mutation in the CBS gene. This study was conducted to identify the clinical features and prognosis of homocystinuria as well as to find out the CBS gene mutations of the six homocystinuria patients who were receiving treatment in the Pediatric Department at Soonchunhyang University Hospital. Methods: From January 1992 to March 2015, clinical, biochemical, and genetic analyses were performed retrospectively on the six patients diagnosed with classic homocystinuria at Soonchunhyang University Hospital. Results: A total of six patients were included in this study, including three who were diagnosed with homocystinuria at the mean age of $50{\pm}22.5$ days based on their abnormal newborn screening test results. The other three were diagnosed at the mean age of 7, when they visited the hospital for evaluation of developmental delay and lens dislocation. The group diagnosed at early infancy had normal cognitive function, but the other group had varying degrees of mental retardation. Major complications were found only in the group diagnosed after infancy. CBS gene mutation was found in all the patients, and they were all non-responsive to vitamin B6 treatment. At present, all patients' diets are controlled following a methionine-free formula and they are on medication with folic acid, betaine, pyridoxine, and methylcobalamin. Conclusion: Six homocystinuria patients were monitored for up to 23 years. The group diagnosed at early infancy exhibited no major complications. Therefore, early diagnosis is crucial in the prognosis, and homocystinuria must be included in the newborn screening program.

A case of Smith-Lemli-Opitz syndrome diagnosed by identification of mutations in the 7-dehydrocholesterol reductase (DHCR7) gene (7-dehydrocholesterol reductase (DHCR7) 변이로 진단된 Smith-Lemli-Opitz 증후군 1예)

  • Park, Mee Rim;Ko, Jung Min;Cheon, Chong-Keun;Kim, Gu-Hwan;Yoo, Han-Wook
    • Clinical and Experimental Pediatrics
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    • v.51 no.11
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    • pp.1236-1240
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    • 2008
  • Smith-Lemli-Opitz syndrome (SLOS) is a rare, autosomal recessive disease caused by an inborn error in cholesterol synthesis. Patients with this disease suffer from multiple malformations due to reduced activity of 7-dehydrocholesterol reductase (DHCR7), which increases 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC) concentrations and decreases cholesterol concentration in body fluids and tissue. The SLOS phenotypic spectrum ranges from a mild disorder with behavioral and learning problems to a lethal disease characterized by multiple malformations. Here, we describe a newborn male with ambiguous genitalia who was diagnosed to have type II SLOS during the neonatal period. A clinical examination revealed low levels of unconjugated estriol in the maternal serum, and a variety of fetal ultrasound anomalies, including prenatal growth retardation. After birth, the infant was diagnosed to have congenital heart disease (Tetralogy of Fallot with severe pulmonary artery stenosis), cleft lip and palate, micrognathia, postaxial polydactyly, ambiguous genitalia, and cataracts. Clinical investigation revealed extremely low plasma cholesterol levels and the presence of mutation (homozygote of p.Arg352Gln) in the DHCR7 gene. The patient underwent palliative heart surgery (to widen the pulmonary artery) and received intravenous lipid supplementation. Cholesterol levels increased slightly, but not to normal values. The patient died from cardiopulmonary failure and sepsis 72 days after birth. This report provides the first description of a Korean patient with SLOS confirmed by verification of DHCR7 gene mutation and illustrates the need for early recognition and appropriate diagnosis of this disease.

A Twin diagnosed with Duarte Variant/Classical (D/G) Galactosemia (Duarte Variant/Classical Galactosemia (D/G) Heterozygote으로 진단된 일란성 쌍둥이 1례)

  • Koo, Kyo Yeon;Lee, Chul Ho;Yang, Jeong Yoon;Lee, Jin-Sung
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.12 no.1
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    • pp.58-63
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    • 2012
  • Classical galactosemia (OMIM# 230400) is an autosomal recessive disorder of carbohydrate metabolism, due to a complete loss in galactose-1-phosphate uridyltransferase (GALT; E.C.2.7.7.12) enzyme activity. It caused by mutations in the GALT gene (OMIM$^*$ 606999) that is located at chromosome 9p13. The GALT enzyme deficiency results in a build-up of galactose and galactose-1-phosphate, causing life threatening complications such as feeding problems, failure to thrive, hepatocellular damage, bleeding and sepsis. However, Duarte galactosemia, a variant form of GALT deficiency, has residual GALT enzyme activities in erythrocytes and do not have manifest the symptoms of classical galactosemia. Since the advent of newborn screening (NBS) for galactosemia, we rarely encounter such overwhelmingly ill newborns. The positive NBS with no symptoms indicates the possibility of Duarte galactosemia besides a simple false positive and it has to be differentiated from classical galactosemia which is a medical emergency. In Korea, detection rate of Duarte galactosemia is very low and its genetic information is restrictive, too. We report a case of monozygotic twins with D/G galactosemia compound heterozygote in proven by the mutational analysis of GALT gene, which revealed N314D polymorphism and -119 to -116 delGTCA.

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A Case of Neonatal Intrahepatic Cholestasis Caused by Citrin Deficiency (NICCD) Confirmed by SLC25A13 Mutation

  • Son, Yeong-Bae;Jang, Ju-Yeong;Park, Hyeong-Du;Lee, Su-Yeon
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.14 no.2
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    • pp.186-190
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    • 2014
  • Citrullinemia type 2 (citrin deficiency) is an autosomal recessive inborn error metabolism, caused by the SLC25A13 gene mutation. Citrin deficiency is associated with two clinical phenotype; neonatal-onset type II citrullinemia (CTLN2), also known as neonatal intraphepatic cholestasis caused by citrin deficiency (NICCD) and adult-onset CTLN2. Clinical manifestations of NICCD include poor growth, intrahepatic cholestasis, liver dysfunction and increased plasma citrulline, methionine, threonine, arginine. The molecular diagnosis could be confirmed by SLC25A13 gene mutation analysis. A 3-month-old male infant with persistent jaundice was referred for evaluation. Newborn screening was normal at birth. Mild elevation of serum ammonia and AST/ALT were observed. Plasma amino acid analysis showed significantly elevated citrulline, methionine, threonine. DNA sequence analysis of the SLC25A13 gene revealed two compound heterozygous mutations, c.[852_855del]($p.Met285Profs^*2$) and [1180+1G>A]. We suggest that NICCD should be considered as one of the cause of in infants with cholestatic jaundice, although the newborn screening was normal.

Coat colour phenotype of Qingyu pig is associated with polymorphisms of melanocortin receptor 1 gene

  • Wu, Xiaoqian;Tan, Zhendong;Shen, Linyuan;Yang, Qiong;Cheng, Xiao;Liao, Kun;Bai, Lin;Shuai, Surong;Li, Mingzhou;Li, Xuewei;Zhang, Shunhua;Zhu, Li
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.7
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    • pp.938-943
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    • 2017
  • Objective: Qingyu pig, a Chinese indigenous pig breed, exhibits two types of coat colour phenotypes, including pure black and white with black spotting respectively. Melanocortin receptor 1 (MC1R) and agouti signaling protein (ASIP) are two widely reported pivotal genes that significantly affect the regulation of coat colour. The objectives of this study were to investigate whether the polymorphisms of these two genes are associated with coat colour and analyze the molecular mechanism of the coat colour separation in Qingyu pig. Methods: We studied the phenotype segregation and used polymerase chain reaction amplification and Sanger sequencing to investigate the polymorphism of MC1R and ASIP in 121 Qingyu pigs, consisting of 115 black and 6 white with black spotted pigs. Results: Coat colour of Qingyu pig is associated with the polymorphisms of MC1R but not ASIP. We only found 2 haplotypes, $E^{QY}$ and $E^{qy}$, based on the 13 observed mutations from MC1R gene. Among which, $E^{qy}$ presented a recessive inheritance mode in black spotted Qingyu pigs. Further analysis revealed a g.462-463CC insertion that caused a frameshift mutation and a premature stop codon, thus changed the first transmembrane domain completely and lost the remaining six transmembrane domains. Altogether, our results strongly support that the variety of Qingyu pig's coat colour is related to MC1R. Conclusion: Our findings indicated that black coat colour in Qingyu pig was dominant to white with black spotted phenotype and MC1R gene polymorphism was associated with coat colour separation in Qingyu pig.

Population genetic variations of the matrix metalloproteinases-3 gene revealed hypoxia adaptation in domesticated yaks (Bos grunniens)

  • Ding, Xuezhi;Yang, Chao;Bao, Pengjia;Wu, Xiaoyun;Pei, Jie;Yan, Ping;Guo, Xian
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.12
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    • pp.1801-1808
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    • 2019
  • Objective: As an iconic symbol of Qinghai-Tibetan Plateau and of high altitude, yak are subjected to hypoxic conditions that challenge aerobic metabolism. Matrix metalloproteinases-3 (MMP3) is assumed to be a key target gene of hypoxia-inducible factor-$1{\alpha}$ that function as a master regulator of the cellular response to hypoxia. Therefore, the aim of this investigation was to identify the DNA polymorphism of MMP3 gene in domestic yak and to explore its possible association with high-altitude adaptation. Methods: The single-nucleotide polymorphisms (SNPs) genotyping and mutations scanning at the MMP3 locus were conducted in total of 344 individuals from four domestic Chinese yak breeds resident at different altitudes on the Qinghai-Tibetan Plateau, using high-resolution melting analysis and DNA sequencing techniques. Results: The novel of SNPs rs2381 $A{\rightarrow}G$ and rs4331 $C{\rightarrow}G$ were identified in intron V and intron VII of MMP3, respectively. Frequencies of the GG genotype and the G allele of SNP rs2381 $A{\rightarrow}G$ observed in high-altitude Pali yak were significantly higher than that of the other yak breeds resident at middle or low altitude (p<0.01). No significant difference was mapped for SNP rs4331 $C{\rightarrow}G$ in the yak population (p>0.05). Haplotype GC was the dominant among the 4 yak breeds, and Pearson correlation analysis showed that the frequencies of GC was significantly lower in Ganan (GN), Datong (DT), and Tianzhu white yaks (TZ) compared with Pali (PL) yak. The two SNPs were in moderate linkage disequilibrium in high-altitude yaks (PL) but not in middle-altitude (GN, DT) and low-altitude (TZ) yaks. Conclusion: These results indicate that MMP3 may have been subjected to positive selection in yak, especially that the SNP rs2381 $A{\rightarrow}G$ mutation and GC haplotypes might contribute to adaptation for yak in high-altitude environments.