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PubMed2002

Cytogenetic alterations in lymphocytes of Alzheimer's disease and Parkinson's disease patients.

We investigated the presence of cytogenetic alterations in peripheral blood lymphocytes of Alzheimer's disease (AD) and Parkinson's disease (PD) patients. Detection of spontaneous structural and/or numerical chromosome damage has been assessed by micronucleus (MN) assay coupled with fluorescence in situ hybridization (FISH). The cytogenetic investigation was performed on 22 AD patients, 18 PD patients, and 20 controls. The spontaneous frequencies of micronuclei (MN) in human lymphocytes of both AD and PD patients were significantly higher than in controls. The majority of MN was composed of whole chromosomes in AD patients, while a prevalence of MN arising from chromosome breakage was observed in PD patients. Different molecular mechanisms underlie cytogenetic alterations observed in peripheral lymphocytes of AD and PD patients.

Aged↗
PubMed2007

Generation of an improved cytogenetic and comparative map of Bos taurus chromosome BTA27.

Comparative genome analysis in cattle, human, and mouse identified various evolutionary breakpoints between Bos taurus 27 chromosome (BTA27) and corresponding segments in the Homo sapiens 4 and 8 chromosomes (HSA4, HSA8) and the Mus musculus 8 chromosome (MMU8). The fragmentary cytogenetic location of breaks is based on nine known loci and Zoo-FISH data on BTA27. A comparative mapping approach combining in-silico mapping and physical mapping by fluorescence in-situ hybridization (FISH) revealed an improved cytogenetic map of BTA27 based on 25 new and nine existing assignments of loci. Furthermore, hybrid cell mapping techniques identified and anchored three additional gene loci on BTA27. The BTA27 map was compared with available mapping and annotated sequence data for the chromosome and a generated comparative map displays conserved syntenic chromosome blocks between cattle, human, and mouse. The new anchor loci identify and narrow down evolutionary breakpoints on a cytogenetic level and can help to support the cattle genome assembly and annotation process.

Animals↗
PubMed2003

Molecular cytogenetic analysis of solid tumors.

Molecular cytogenetic methods including fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) can be used for surgically removed solid tumors to obtain information valuable for both biomedical research and clinical oncology. FISH allows cytogenetic analysis even of cells in interphase. In addition, because CGH analysis permits comprehensive analysis of alterations in DNA copy number in a single experiment, it is possible to estimate not only the genetic pathways of carcinogenesis but also the biological characteristics, such as metastatic potential and patient prognosis at the time of diagnosing the solid tumor. The number of DNA copy number aberrations increases with tumor progression, leading to the concept of genetic staging of malignant tumors. Molecular cytogenetic analysis aids in realizing individualized, tailored medicine in cancer patients; therapeutic strategies are constructed for individual patients based on specific genetic alterations.

Cytogenetic Analysis↗
PubMed1988

Cytogenetic observations of a human ovarian carcinoma clinically resistant to therapy.

Resistance of a cancer cell to therapy represents an important problem in tumor biology. Hypotheses concerning the mechanism of resistance have included genetic instability, gene amplification, aneuploidy, and altered cell growth kinetics. Cytogenetic assays allow for the analysis of each of these parameters and provide important information concerning tumor heterogeneity. In using cytogenetic analysis, we have analyzed a human ovarian carcinoma clinically resistant to therapy. The ovarian carcinoma had a complex but stable karyotype with a mean chromosome number of 61.7 chromosomes/cell. Approximately 50% of the metaphase preparations examined had double-minute chromosomes, which have sometimes been associated with gene amplification. The frequency of double minutes varied from one pair to hundreds of pairs per cell. Cell cycle kinetic analysis revealed an average generation time of 38 hours. The cells were relatively resistant to doxorubicin in vitro, and the baseline sister chromatid exchange frequency, a measure of genetic instability, was elevated. These results suggest that cytogenetic assays have potential as predictive assays of tumor chemoresistance and may provide information regarding the biologic aggressiveness encountered clinically.

Cell Cycle↗
PubMed1985

Tabulation and assessment of 113 human surveillance cytogenetic studies conducted between 1965 and 1984.

There is an increasing tendency to monitor human exposure to genotoxic chemicals by the assessment of chromosomal aberrations or sister-chromatid exchanges (SCEs) in peripheral blood lymphocytes. In order to assess the sensitivity of these techniques, and to discern minimal criteria for their conduct, a survey of 113 human lymphocyte cytogenetic surveillance studies conducted between 1965 and 1984 has been undertaken. The present survey indicates the urgent need for standardization of study protocols. It is suggested that a common method of reporting chromosomal aberrations should be adopted, and that this should be based on the system described by Scott et al. It is also suggested that a minimum acceptable size of control and exposed populations should be agreed, and that potentially important factors such as the gender, the period and extent of exposure and individual smoking habits be defined in advance of the commission of future surveillance studies. As general awareness of the possible hazard presented by exposure of man to genotoxic chemicals increases, so appropriate preventative industrial hygiene measures will be instituted. This implies that future human cytogenetic surveillance studies may yield either weakly positive or negative data. This emphasizes the current need for agreement on appropriate study protocols. The formation of a central repository for control databases, and its subsequent updating and use by those involved in human cytogenetic surveillance studies, is recommended. Minimal experimental criteria for the design of future studies are also outlined.

Carcinogens, Environmental↗
PubMed1991

Normal cytogenetic values for bone marrow based on studies of bone marrow transplant donors.

For individuals suspected of having hematologic neoplasms, interpretation of the clinical significance of sporadic cells with chromosome breakage, structural anomalies, aneuploidy, or polyploidy is often difficult. To help resolve this problem, we established normal cytogenetic values for bone marrow (BM) by investigating 219 BM transplant (BMT) donors using standard techniques for chromosome analysis. The donors ranged in age from 2 to 58 years and were studied for 7 years. The constitutional karyotype for two individuals was 47,XXY; one was mos45,X/46,XX, one was mos46,XX/47,XX, + mar, and 215 were normal. Among other statistics, the median and normal ranges (95th percentile) were determined for any kind of chromosome abnormality, autosomal loss, autosomal gain, sex chromosome loss, sex chromosome gain, chromosome breaks or gaps, major structural abnormalities, and polyploidy. The results suggest that random loss of chromosomes is common in cytogenetic preparations of BM, appears to be largely technical and is inversely proportional to chromosome size. Cells with extra chromosomes or with structural abnormalities are rare in normal BM. No specific sporadic structural abnormalities of chromosomes are associated with normal BM. The widely accepted cytogenetic definition for an abnormal clone appears to be valid, with the possible exception of occasional studies involving loss of smaller autosomes. There may be a correlation between loss of the Y chromosome and age of the patient.

Adolescent↗
PubMed1993

Defining the extent and nature of cytogenetic events in prostatic adenocarcinoma: paraffin FISH vs. metaphase analysis.

A comparative study of primary prostatic tumors utilizing conventional metaphase analysis of prostate tumor cultures and fluorescence in situ hybridization (FISH) analysis of paraffin-embedded tissue sections revealed significant differences in type and extent of cytogenetic aberrations. Clonal trisomy 7 was identified in two tumors by metaphase analysis of prostate cultures, but not confirmed in either case by FISH analysis. True gain of chromosome 8 was revealed by FISH analysis in malignant epithelium of four tumors but not in adjacent normal or hyperplastic glands. Neither gain nor loss of this chromosome was observed by metaphase analysis in any of the tumors. Significant monosomy and nullisomy of chromosome 10 was identified in one case by FISH, but no cells with gain or loss of chromosome 10 were observed by metaphase analysis. Significant loss of the Y chromosome was revealed in one tumor by FISH, but no cells with -Y were identified by metaphase analysis. Clonal loss of the Y chromosome was identified in two other tumors by metaphase analysis. Paraffin FISH analysis of these tumors revealed overall monosomy in both, although in one tumor there was extensive nodular loss of the Y chromosome. Paraffin FISH analysis permits identification of cytogenetic aberrations in areas identified as carcinoma (CaP), prostatic intraepithelial neoplasia (PIN), and benign prostatic hyperplasia (BPH). This technique appears more informative in defining the true extent and nature of cytogenetic aberrations in prostate cancer than metaphase analysis of prostate tumor cultures.

Adenocarcinoma↗
PubMed1993

Management of cytogenetic data in multi-center leukemia trials.

This paper provides methods for storing and retrieving cytogenetics data, which must reside jointly in a reference laboratory and in a data co-ordinating center. The major piece of data is the character string that uses the International System for Human Cytogenetic Nomenclature. Simple and complex data retrieval, using Statistical Analysis System (SAS) functions INDEX and SUBSTR, are illustrated. Use of the methods of this paper can save considerable costs in setting up cytogenetic data systems compared with other proposed systems which have come to the authors' attention.

Child↗
PubMed2006

The achievement of durable complete cytogenetic remission in late chronic and accelerated phase patients with CML treated with Imatinib mesylate predicts for prolonged response at 6 years.

Despite the positive results achieved by Imatinib mesylate (Imatinib) in the treatment of chronic myeloid leukemia (CML), over the past several years, Imatinib does not eradicate the leukemic clone. The long-term duration of response to the drug is not known. Long-term follow-up of CML patients treated with Imatinib will ultimately define the durability of such treatment and the frequency of reemergence of progressive disease. We present the results of a 6-year follow-up of 40 CML patients either in chronic or accelerated phase who obtained a durable (>6 months) complete cytogenetic remission (CCyR) after treatment with Imatinib in a single center. In 34 cases CCyR was obtained at an Imatinib dose of 400-600 mg/day and in 6 cases after a dose increase to 600-800 mg/day. At a median follow-up of 68 months, 6 cytogenetic relapses (15%) were observed. No progressions to more advanced phases of disease have been detected during the follow-up period. Cytogenetic relapse was predicted by either a decrease in the amount of BCR-ABL transcript of less than 2 logs after the achievement of CCyR (p=0.0041) or a time-to-CCyR of more than 12 months (p<0.0001). This 6-year follow-up of the efficacy of Imatinib therapy in CML patients who obtained a durable CCyR indicates that the relapses rate is low over this period of observation and that the rate of relapse does not increase over time.

Adult↗
PubMed2004

The use of cytogenetics in understanding ovarian cancer.

The future of cancer research is no longer limited to epidemiological data and clinical management, but rather encompasses a new dimension of understanding, that involves genetics of the tumors themselves. This has been exemplified most prominently in hematological tumors where alterations at the DNA level have been found to play key roles in the pathophysiology, diagnosis, monitoring and prognosis of these tumors. It has been shown over the last 20 years that recurrent chromosomal rearrangements are strongly associated with the activation of oncogenes, acquisition of drug resistance and loss of tumor suppressor gene function. Chromosomal alterations have also been shown to characterize many solid tumors, including epithelial ovarian cancer [Cancer Res. 62 (2002) 3466; Cancer 91 (2001) 534; Genes Chromosomes Cancer 25 (1999) 290]. Despite these findings, however, there are currently few examples of specific cytogenetic studies that have contributed to the clinical management of solid tumors such as ovarian cancer. The limiting factor to date is the resolution of available techniques. With time, as the technology improves, so will our ability to focus on specific findings that may be applicable to future clinical management. The intention of this report is to familiarize the reader with the evolution of cytogenetic and molecular cytogenetic techniques used in the study of ovarian cancer, the early formulations from these studies and their use in answering specific clinical questions such as association with pathologic subtype, the relevance of drug resistance, the impact of BRCA mutations, and finally to guide the reader into the future of this ever growing field.

Animals↗
PubMed2006

Cutaneous aneurysmal fibrous histiocytoma with a t(12;19)(p12;q13) as the sole cytogenetic anomaly.

We report a case of a 39-year-old woman with a recurrent aneurysmal fibrous histiocytoma of the right lower leg. Cytogenetic analysis of the tumor specimen disclosed a 46,XX,t(12;19)(p12;q13) karyotype. Multicolor fluorescence in situ hybridization (M-FISH), followed by conventional FISH analysis, confirmed the reciprocal translocation as the sole cytogenetic anomaly, and allowed for the positioning of chromosomes 12 and 19 breakpoints proximal to the BCL3 gene and between ETV6 and PIK3C2G gene loci, respectively. Our case highlights the importance of distinguishing this recurrent but benign lesion from similarly appearing malignant skin tumors. Cytogenetic analysis may contribute to the diagnosis of this uncommon but distinctive clinicopathological entity.

Adult↗
PubMed2005

Cytogenetic analysis of azoospermic patients: karyotype comparison of peripheral blood lymphocytes and testicular tissue.

OBJECTIVE: The objective was to compare the results of a complete chromosomal, genetic and histological investigation in 13 azoospermic men with the results of the intracytoplasmic sperm injection (ICSI) procedure. STUDY DESIGN: Peripheral blood samples were used for the measurement of follicle-stimulating hormone (FSH) levels, chromosomal analysis, microdeletions in the azoospermia factor (AZF) region of the Y chromosome and cystic fibrosis transmembrane conductance regulator (CFTR) mutation analysis. Testicular tissue was used for histological scoring and cytogenetic evaluation. RESULTS: Peripheral blood cytogenetic analysis revealed a normal male karyotype in all cases. Chromosomal analysis from testicular tissue revealed a mosaicism for the terminal deletion of chromosome 22 with a breakpoint site at 22q13 in one patient with congenital bilateral absence of the vas deferens (CBAVD). Deletions in the AZFa, ATFb, and AZFc regions were not detected. The CFTR mutational analysis showed normal results in all patients. CONCLUSIONS: Cytogenetic evaluation of testicular tissue should be performed in non-obstructive and obstructive azoospermic patients as well as in patients with multiple failed IVF and recurrent spontaneous abortion.

Adult↗
PubMed2005

[The cytogenetics of human oocytes: 40 years of progress].

Chromosomal abnormalities account for the majority of pre- and post- implantation embryo wastage in humans. Most of these abnormalities result from maternal meiotic errors, which preferentially occur during the first meiotic division. Consequently, the cytogenetic analysis of human oocytes has then been considered as a highly valuable source of data for the investigation of both the occurrence and the origin of chromosomal abnormalities in human. During the last 4 decades, the cytogenetic analysis of human oocytes has never stopped progressing, according to the advents of new technologies. Both karyotyping and molecular cytogenetic studies have been reported to date, providing a large body of data on the incidence and the distribution of chromosomal abnormalities in human female gametes. However, these studies display a great variability in results, which may be essentially attributable to the limitations of these techniques when applied to human oocytes. The most relevant analysis have led to the estimate that 15-20% of human oocytes present chromosome abnormalities, and they have emphasized the implication of both whole chromosome non-disjunction and chromatid separation in the occurrence of aneuploidy in human oocytes. The effect of advanced maternal age on the incidence of aneuploidy in human oocytes has also been clearly evidenced by recent reports based on large sample of oocytes or polar bodies.

Cell Division↗
PubMed2006

Efficacy of conventional cytogenetics and FISH for EGR1 to detect deletion 5q in hematological disorders and to assess response to treatment with Lenalidomide.

In clinical practice, whether FISH for EGR1 in interphase nuclei has similar efficacy to detect deletion 5q anomalies as conventional cytogenetic studies is unknown. We compared conventional cytogenetics and FISH for 145 patients with deletion 5q and detected this anomaly by both methods in 144. Nine patients with myelodysplasia were studied before and after treatment with Lenalidomide and results were concordant for 28 of 29 specimens. FISH did not detect anomalies other than deletion 5q in 31 patients. This study suggests FISH is useful to detect deletion 5q, but is not a substitute for conventional cytogenetics.

Adult↗
PubMed2004

Cytogenetic biomarkers and genetic polymorphisms.

Cytogenetic biomarkers have long been applied in surveillance of human genotoxic exposure and early effects of genotoxic carcinogens. Due to their wide use, it has been possible to evaluate, in international collaborative studies, if a high level of these biomarkers in peripheral lymphocytes is predictive of cancer risk. Thus far, such an association has been observed for chromosomal aberrations (CAs), but not for sister chromatid exchanges (SCEs) or micronuclei (MN). The cancer risk predictivity of CAs was not dependent on the time between CA analysis and cancer detection and did not appear to be explained by tobacco smoking or occupational exposure to carcinogens but was seen in unexposed non-smokers as well. This suggests a role for individual susceptibility factors. Genetic polymorphisms of various xenobiotic-metabolising enzymes, influencing the metabolic activation and detoxification of carcinogens, have been associated with cancer risk, and some of them also appear to affect cytogenetic biomarkers. The lack of glutathione S-transferase M1 (GSTM1 null genotype) is associated with increased sensitivity to genotoxicity of tobacco smoke, and GSTM1 null smokers also show an increased frequency of CAs and SCEs. N-Acetyltransferase (NAT2) slow acetylation genotype and glutathione S-transferase T1 (GSTT1) null genotype seem to elevate the baseline level of CAs and SCEs and CAs, respectively--possibly because of reduced capacity to detoxify some wide-spread or endogenous genotoxins. For some chemicals, in vitro cytogenetic studies with lymphocyte donors representing different genotypes have been able to predict a differential in vivo response. For instance, in vitro SCE induction by styrene and by epoxide metabolites of 1,3-butadiene is modified by GSTM1 and GSTT1 genotypes--which also influence the excretion of specific mercapturic acids in humans exposed to butadiene and styrene. Polymorphisms of DNA repair and folate metabolism are expected to be of special importance in modulating genotoxic effects. Some evidence exists for the effects of X-ray cross complementation group 1 (XRCC1) codon 280 and (in smokers) Xeroderma pigmentosum group D (XPD) codon 23 polymorphisms on baseline CAs, for XRCC1 codon 399 polymorphism on SCEs in smokers, and for methylene tetrahydrofolate reductase (MTHFR) codon 677 and methionine synthase reductase (MTRR) polymorphisms on spontaneous MN.

Animals↗
PubMed1996

Molecular cytogenetics: an essential component of modern prenatal diagnosis.

Traditional cytogenetic studies with high-resolution banding techniques have been the mainstay of prenatal diagnosis for > 20 years. However, this approach is limited by the resolution of light microscopy, and it requires cultured cells, necessitating a significant delay in obtaining chromosome studies. The advent of molecular cytogenetics, or fluorescence in situ hybridization, has added an adjunctive tool to overcome both these limitations. During a 16-month period 35 prenatal diagnosis cases had molecular cytogenetic studies performed; 71% of the evaluations were informative. We present five of these cases to illustrate the benefits of this technique for clinical prenatal diagnosis.

Adolescent↗
PubMed2000

Location and function of critical genes in leukemogenesis inferred from cytogenetic abnormalities in hematologic malignancies.

Dramatic advances in the cytogenetic analysis of chromosomal rearrangements of hematopoietic malignancies have occurred over the past years. These are due to considerable improvement in the techniques of molecular cytogenetics. Various applications of fluorescence in situ hybridization (FISH), used in conjunction with conventional cytogenetics, make the recognition of some abnormalities easier, and the localization of chromosomal breakpoints in structural rearrangements more precise. Under many circumstances, accurate breakpoint localization is the first step toward the identification of genes involved in translocations and inversions. Some of the genes recently discovered may be rearranged with several partner genes. These promiscuous genes are natural experiments that generate mutants which help to identify the function of genes rearranged in hematopoietic malignancies as well as that of their normal counterparts. The diversity of the genes implicated in leukemogenesis makes their functional study a challenge, but, as recently shown by their role in chromatin remodeling, increasing recognition of cross-talk between many of these genes justifies the development of analyses of leukemia-associated chromosome abnormalities and of their functional consequences.

Cell Transformation, Neoplastic↗
PubMed1996

Chromosome abnormalities in colorectal adenomas: two cytogenetic subgroups characterized by deletion of 1p and numerical aberrations.

Cytogenetic analysis of short-term cultures from 34 benign colorectal polyps, all histologically verified as adenomas, revealed clonal chromosome aberrations in 21 of them. Eight polyps had structural rearrangements, whereas only numerical changes were found in 13. A combination of structural and numerical chromosomal aberrations was found in three polyps. The most common numerical change was gain of chromosome 7, found either as the sole anomaly (five polyps), together with other numerical changes (six polyps), or together with structural rearrangements (two polyps). Other recurrent numerical changes were +20, +13, and monosomy 18, found in six, five, and two adenomas, respectively. Rearrangement of chromosome 1 was the most common structural change. Abnormalities involving 1p were seen in six adenomas, leading to visible loss of material in three. One adenoma had one clone with a large and another with a small 1p deletion. In three adenomas, del(1)(p36) was the only cytogenetic aberration, supporting the authors' previous conclusion that loss of one or more gene loci in band 1p36 is a common early change in colorectal tumorigenesis. Chromosome 8 was involved in structural changes in two adenomas; in one this led to loss of 8p and in the other to gain of 8q. The cytogenetic findings did not correlate in a statistically significant manner with clinicopathologic parameters, such as grade of dysplasia, macroscopic or microscopic adenoma structure, tumor size and location, or the patients' sex and age.

Adenoma↗