• Title, Summary, Keyword: aneuploidy

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How Chromosome Mis-Segregation Leads to Cancer: Lessons from BubR1 Mouse Models

  • Lee, Hyunsook
    • Molecules and Cells
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    • v.37 no.10
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    • pp.713-718
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    • 2014
  • Alteration in chromosome numbers and structures instigate and foster massive genetic instability. As Boveri has seen a hundred years ago (Boveri, 1914; 2008), aneuploidy is hall-mark of many cancers. However, whether aneuploidy is the cause or the result of cancer is still at debate. The molecular mechanism behind aneuploidy includes the chromosome mis-segregation in mitosis by the compromise of spindle assembly checkpoint (SAC). SAC is an elaborate network of proteins, which monitor that all chromosomes are bipolarly attached with the spindles. Therefore, the weakening of the SAC is the major reason for chromosome number instability, while complete compromise of SAC results in detrimental death, exemplified in natural abortion in embryonic stage. Here, I will review on the recent progress on the understanding of chromosome missegregation and cancer, based on the comparison of different mouse models of BubR1, the core component of SAC.

Validation of fetus aneuploidy in 221 Korean clinical samples using noninvasive chromosome examination: Clinical laboratory improvement amendments-certified noninvasive prenatal test

  • Kim, Min-Jeong;Kwon, Chang Hyuk;Kim, Dong-In;Im, Hee Su;Park, Sungil;Kim, Ji Ho;Bae, Jin-Sik;Lee, Myunghee;Lee, Min Seob
    • Journal of Genetic Medicine
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    • v.12 no.2
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    • pp.79-84
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    • 2015
  • Purpose: We developed and validated a fetal trisomy detection method for use as a noninvasive prenatal test (NIPT) including a Clinical Laboratory Improvement Amendments (CLIA)-certified bioinformatics pipeline on a cloud-based computing system using both Illumina and Life Technology sequencing platforms for 221 Korean clinical samples. We determined the necessary proportions of the fetal fraction in the cell-free DNA (cfDNA) sample for NIPT of trisomies 13, 18, and 21 through a limit of quantification (LOQ) test. Materials and Methods: Next-generation sequencing libraries from 221 clinical samples and three positive controls were generated using Illumina and Life Technology chemistries. Sequencing results were uploaded to a cloud and mapped on the human reference genome (GRCh37/hg19) using bioinformatics tools. Based on Z-scores calculated by normalization of the mapped read counts, final aneuploidy reports were automatically generated for fetal aneuploidy determination. Results: We identified in total 29 aneuploid samples, and additional analytical methods performed to confirm the results showed that one of these was a false-positive. The LOQ test showed that the proportion of fetal fraction in the cfDNA sample would affect the interpretation of the aneuploidy results. Conclusion: Noninvasive chromosome examination (NICE), a CLIA-certified NIPT with a cloud-based bioinformatics platform, showed unambiguous success in fetus aneuploidy detection.

Outcome of Preimplantation Genetic Diagnosis for Chromosome Aneuploidy and Genetic Disease (유전질환 및 염색체 이상의 예방을 위한 착상전 유전진단의 결과)

  • Kim, Jin-Yeong;Lim, Chun-Kyu;Song, In-Ok;Yoo, Keun-Jai;Yang, Kwang-Moon;Han, Kuk-Sun;Hur, Kuol;Song, Ji-Hong;Jun, Jin-Hyun;Min, Dong-Mi;Park, So-Yeon;Jun, Jong-Young;Koong, Mi-Kyoung;Kang, Inn-Soo
    • Clinical and Experimental Reproductive Medicine
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    • v.29 no.4
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    • pp.269-278
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    • 2002
  • Objective s: Chromosome aneuploidy is associated with recurrent abortion and congenital anomaly and genetic diseases occur repeatedly in the specific families. Preimplantation genetic diagnosis (PGD) can prevent aneuploidy or genetic disease by selecting normal embryos before implantation and is an alternative to prenatal diagnosis. The aim of this study is to assess the outcome of PGD cycles by using FISH or PCR, and to determine the clinical usefulness and values in patients with risk of chromosomal aneuploidy or genetic disease. Materials and Methods: From 1995 to Apr. 2001, a total of 108 PGD cycles in 65 patients with poor reproductive outcome were analyzed. The indications of PGD were translocation (n=49), inversion (n=2), aneuploidy screening (n=7), Duchenne muscular dystrophy (n=5) and spinal muscular atrophy (n=2). PGD was applied due to the history of recurrent abortion, previous birth of affected child or risk of aneuploidy related to sex chromosome aneuploidy or old age. Blastomere biopsy was performed in 6$\sim$10 cell stage embryo after IVF with ICSI. In the single blastomere, chromosome aneuploidy was diagnosed by using FISH and PCR was performed for the diagnosis of exon deletion in DMD or SMA. Results: The FISH or PCR amplification was successful in 94.3% of biopsied blastomeres. The rate of transferable balanced emb ryos was 24.0% in the chromosome translocation and inversion, 57.1% for the DMD and SMA, and 28.8% for the aneuploidy screening. Overall hCG positive rate per transfer was 17.8% (18/101) and clinical pregnancy rate was 13.9% (14/101) (11 term pregnancy, 3 abortion, and 4 biochemical pregnancy). The clinical pregnancy rate of translocation and inversion was 12.9% (11/85) and abortion rate was 27.3% (3/11). In the DMD and SMA, the clinical pregnancy rate was 33.3% (3/9) and all delivered at term. The PGD results were confirmed by amniocentesis and were correct. When the embryos developed to compaction or morula, the pregnancy rate was higher (32%) than that of the cases without compaction (7.2%, p<0.01). Conclusions: PGD by using FISH or PCR is useful to get n ormal pregnancy by reducing spontaneous abortion associated with chromosome aneuploidy in the patients with structural chromosome aberration or risk of aneuploidy and can prevent genetic disease prior to implantation.

Analysis of radiation-induced micronuclei and aneuploidy involving chromosome 1 and 4 by FISH technique (FISH 기법을 이용한 방사선에 의한 소핵과 이수성 분석)

  • Chung, Hai-Won;Kim, Tae-Yon;Cho, Yoon-Hee;Kim, Su-Young;Kang, Chang-Mo;Ha, Sung-Whan
    • Journal of Radiation Protection and Research
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    • v.29 no.4
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    • pp.243-249
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    • 2004
  • The cytokinesis-block micronucleus (CBMN) assay in combination with FISH technique using chromosome-specific centromeric probes for chromosome 1 and 4 was performed in mitogen stimulated human lymphocytes which were exposed to x-radiation to identify different sensitivity of chromosomes to the induction of micronuclei(MN) and aneuploidy by radiation. The frequencies of micronucleated cytokinesis-blocked(MNCB) cells and MN in binucleated lymphocytes(BN) increased with the increase in radiation dose. A significant induction of aneuploidy of chromosome 1 and 4 were found. The frequency of aneuploidy of chromosome 1 and 4 in the control were 9 per 2,000 BN cells and this increased to 47 and 71 following irradiation at a dose of 1 and 2 Gy, respectively. The induction of aneuploidy of chromosome 1 was higher than that of chromosome 4. The frequency of aneuploid BN cells with MN exhibiting positive centromere signal for either chromosome 1 and/or 4 increased in a dose dependent manner, and that for chromosome 1 is higher than that for chromosome 4. Among the total induced MN in irradiated lymphocytes, smaller proportion of MN exhibit centromeric signal of chromosome indicating that radiation-induced MN are mainly originated from chromosomal breakage rather than chromosomal non-disjunction. These results suggest that x-radiation can induce aneuploidy and supports the finding that chromosome vary in their sensitivity to aneuploidy induction by x-irradiation.

Effect of Cytosine Arabinoside, 3-Aminobenzamide and Hydroxyurea on the frequencies of radiation-induced micronuclei and aneuploidy in human lymphocytes (DNA 회복 저해제 Cytosine Arabinoside, 3-Aminobenzamide 및 Hydroxyurea가 방사선에 의해 유도된 소핵과 이수성에 미치는 영향)

  • Cho, Yoon-Hee;Kim, Yang-Jee;Kang, Chang-Mo;Ha, Sung-Whan;Chung, Hai-Won
    • Journal of Radiation Protection and Research
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    • v.30 no.4
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    • pp.209-219
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    • 2005
  • This study was carried out to examine the effect of the DNA repair inhibitors, Cytosine Arabinoside(Ara C), 3-Aminobenzamide(3AB) and Hydroxyurea(HU) on the frequencies of radiation-induced micronuclei(MNi) and aneuploidy. Irradiated lymphocytes(1-3Gy) were treated with DNA repair inhibitors, Ara C, 3AB and HU for 3 hours and CBMN assay - FISH technique with DNA probe for chromosome 1 and 4 was performed. The frequencies of x-ray induced MNi and aneuploidy of chromosome 1 and 4 were increased in a dose-dependent manner. Ara C, 3AB and HU enhanced the frequencies of radiation-induced MNi and the frequencies of radiation-induced aneuploidy of chromosome 1 and 4 were enhanced by HU and Ara C while no effect was observed by 3AB. The frequency of radiation-induced aneuploidy of chromosome 1 was higher than that of chromosome 4. These results suggest that there are different mechanisms involved in the formation of MNi and aneuploidy by radiation.

DNA Ploidy in Anaplastic Carcinoma of the Thyroid Gland by Image Analysis (갑상선 역형성암종의 DNA 배수성에 관한 화상분석학적 연구)

  • Lee, Ji-Shin;Lee, Min-Cheol;Park, Chang-Soo;Juhng, Sang-Woo
    • The Korean Journal of Cytopathology
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    • v.6 no.1
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    • pp.10-17
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    • 1995
  • Anaplastic carcinoma of the thyroid gland is one of the most malignant tumors. Recently, DNA ploidy measured by flow cytometry and image analysis has been suggested as an additional useful indicator of tumor behavior. Studies on the occurrence and clinical significance of DNA aneuploidy in anaplastic carcinoma of the thyroid are rare. In this study, the pattern of DNA ploidy was measured by image analysis on Papanicolaou stained slides in four cases of anaplastic carcinoma and also measured by flow cytometry using paraffin blocks in two cases. In all cases of anaplastic carcinoma, DNA aneuploidy was found by image analaysis. By flow cytometry, one case had a diploid peak and the other case had an aneuploid peak. According to the above results, we conclude that anaplastic carcinoma of the thyroid glands have a high incidence of DNA aneuploidy and image analysis using Papanicolaou stained slides is a useful method in detecting DNA aneuploidy.

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Application of digital polymerase chain reaction technology for noninvasive prenatal test

  • Lee, Seung Yong;Hwang, Seung Yong
    • Journal of Genetic Medicine
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    • v.12 no.2
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    • pp.72-78
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    • 2015
  • Recently, noninvasive prenatal test (NIPT) has been adopted as a primary screening tool for fetal chromosomal aneuploidy. The principle of NIPT lies in isolating the fetal fraction of cell-free DNA in maternal plasma and analyzing it with bioinformatic tools to measure the amount of gene from the target chromosome, such as chromosomes 21, 18, and 13. NIPT will contribute to decreasing the need for unnecessary invasive procedures, including amniocentesis and chorionic villi sampling, for confirming fetal aneuploidy because of its higher positive predictive value than that of the conventional prenatal screening method. However, its greater cost than that of the current antenatal screening protocol may be an obstacle to the adoption of this innovative technique in clinical practice. Digital polymerase chain reaction (dPCR) is a novel approach for detecting and quantifying nucleic acid. dPCR provides real-time diagnostic advantages with higher sensitivity, accuracy, and absolute quantification than conventional quantitative PCR. Since the groundbreaking discovery that fetal cell-free nucleic acid exists in maternal plasma was reported, dPCR has been used for the quantification of fetal DNA and for screening for fetal aneuploidy. It has been suggested that dPCR will decrease the cost by targeting specific sequences in the target chromosome, and dPCR-based noninvasive testing will facilitate progress toward the implementation of a noninvasive approach for screening for trisomy 21, 18, and 13. In this review, we highlight the principle of dPCR and discuss its future implications in clinical practice.

The induction of Micronucleus and Aneuploidy in human lymphocytes by Hydroquinone and its association with Genetic Polymorphisms of CYP1A1, GSTM1, GSTT1, NQO1 gene

  • Chung, Eun-Jung;Kim, Tae-Yon;Kim, Jin-Sik;Kim, Yang-Ji;Cho, Yoon-Hee;Chung, Hai-Won
    • Proceedings of the Korean Society of Toxicology Conference
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    • pp.176-176
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    • 2002
  • In order to investigate whether the induction of micronucleus and aneuploidy in human lymphocytes by Hydroquinone (HQ) is associated with genetic polymorphisms of CYP1A1, GSTM1, GSTT1, NQO1 gene, the cytokinesis-block micronucleus (CBMN) assay in combination with fluorescence in situ hybridization (FISH) technique using specific centromeric probes for chromosome 7 and 8 and PCR-RFLP based genotyping for 30 healthy people were performed.(omitted)

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Effects of 60-Hz Magnetic Fields on DNA Damage Responses in HT22 Mouse Hippocampal Cell Lines

  • Mun, Gil-Im;Lee, Seungwoo;Kim, Nam;Lee, Yun-Sil
    • Journal of electromagnetic engineering and science
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    • v.15 no.3
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    • pp.123-128
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    • 2015
  • Previously, we investigated extremely low-frequency magnetic fields (ELF-MFs) on diverse DNA damage responses, such as phosphorylated H2AX (${\gamma}H2AX$), comet tail moments, and aneuploidy production in several non-tumorigenic epithelial or fibroblast cell lines. However, the effect of ELF-MF on DNA damage responses in neuronal cells may not be well evaluated. Here, we investigated the effects of ELF-MF on the DNA damage responses in HT22 non-tumorigenic mouse neuronal cells. Exposure to a 60-Hz, 2 mT ELF-MF did not produce any increased ${\gamma}H2AX$ expression, comet tail moments, or aneuploidy formation. However, 2 mT ELF-MF transiently increased the cell number. From the results, ELF-MF could affect the DNA damage responses differently, depending on the cell lines.

Clinical significance of sonographic soft markers: A review

  • Kim, Mi Sun;Kang, Sukho;Cho, Hee Young
    • Journal of Genetic Medicine
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    • v.15 no.1
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    • pp.1-7
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    • 2018
  • Sonographic findings with little or no pathological significance, known as soft markers, are often found in aneuploidy fetuses. After normal screening for the aneuploidy in first trimester, there are no uniform recommendations regarding when to disregard or put on clinical significance in isolated soft markers. Associations between some soft markers and adverse pregnancy outcomes including intrauterine fetal death, preterm birth, fetal growth restriction, and congenital infection have been reported in euploidy fetuses. The present article aims to review recent literatures about the clinical significance of soft markers after normal first trimester combined screening or noninvasive prenatal testing, and propose a simple clinical summary for management of specific soft markers in pregnancies.