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PubMed1997

Cytogenetics. An evolving role in the diagnosis and treatment of cancer.

Conventional cytogenetics has been used for many years in the diagnosis and follow-up of myeloproliferative disorders. Molecular techniques including FISH and gene rearrangements are complementary in the evaluation of myeloproliferative and myelodysplastic disorders. Lymphomas and lymphocytic leukemias have nonrandom cytogenetic patterns that are useful in the clinical diagnosis, prognosis, and therapeutic follow-up. Solid tumors have complex karyotypic and genetic abnormalities, and clinical utilization of conventional cytogenetics and molecular techniques is in the developmental stages of applicability. The benefits of karyotype analysis in myeloproliferative and lymphoproliferative diseases include guidance for diagnostic and therapeutic approaches as well as assessment of minimal residual disease. Conventional cancer cytogenetics and commercially available FISH reagents enhance these applications. Molecular diagnostic techniques are analytically sensitive and specific. The complexities of the function and role of genetic abnormalities in solid tumors present challenges in the choice, interpretation, and application of conventional cytogenetic and molecular data. These challenges offer exciting potential for future advances.

Cytogenetics↗
PubMed1997

[Application of interphase cytogenetics for the determination of changes in the DNA content in acute childhood lymphoid leukemia].

The authors investigated the usefulness of the interphase cytogenetic approach to reveal numerical chromosomal abnormalities. Experiments performed on normal human cells using chromosome specific (peri)centromeric probes indicated that disomy was recognized in a range of 89.1 +/- 5.4%-96.8 +/- 0.4% for the somatic chromosomes and in 98.1 +/- 0.8% for the sex chromosomes. Using positivity threshold of mean percentage of the fals monosomy and trisomy + 2 SD, chromosome loss or gain for the somatic chromosomes could be revealed beyond clonal ratio of 3.6-13.2% and 1.1-6.8%, respectively. The same value for the sex chromosomes was 3.2% and 0%, respectively. Eleven pediatric acute lymphoid leukaemia were investigated for chromosomal aneuploidy by interphase cytogenetics using chromosome specific (peri)centromeric probes for all the somatic and sex chromosomes. Results were compared with metaphase cytogenetic and flow cytometry derived gross DNA aneuploidy data. In 5 cases the leukaemic cells proved to be diploid with all three methods at both gross DNA and chromosome levels. Interphase cytogenetics revealed chromosome loss or gain in all the remaining 6 cases, however, metaphase analysis indicated numerical aberration in only 2 patients. In one of them only the increased chromosome number could have been detected without identifying the chromosomes involved and in the other one the two methods indicated trisomy for not the same chromosome. Flow cytometry data showed aneuploidy in 3 out of the 6 aneuploid leukaemia. The results imply that interphase cytogenetics might be more accurate as compared with flow cytometry and metaphase analysis to reveale aneuploidy.

Age Factors↗
PubMed1999

Comparative genomic hybridization as a tool in tumour cytogenetics.

The quality of cytogenetic analysis of solid tumours has greatly improved in the past decade, but a number of technical difficulties remain which limit the characterization of solid tumour chromosomes by conventional cytogenetics alone. The identification of regions of chromosomal abnormality has been aided by the introduction of molecular cytogenetic techniques such as fluorescence in situ hybridization (FISH). Of these, a recently developed approach, comparative genomic hybridization (CGH), has had a particular impact on the cytogenetic analysis of solid tumours. It incorporates the sensitivity of in situ techniques and overcomes many of the drawbacks of conventional cytogenetic analysis. This review first outlines the CGH method, giving details for the preparation of DNA probes and target human metaphase chromosomes together with information on the in situ technique and data handling criteria used in our laboratory. It then presents an overview of some of the current applications of CGH, together with a discussion of future directions in the field.

Chromosome Aberrations↗
PubMed2000

Cytogenetic characterization of peripheral nerve sheath tumours: a report of the CHAMP study group.

The findings of characteristic, sometimes pathognomonic, chromosome aberrations in several types of soft tissue tumours have not only added to our understanding of the mechanisms behind the genesis of these tumours, but have also revealed the importance of cytogenetic analysis as a diagnostic tool. For many soft tissue tumours, including peripheral nerve sheath tumours, the number of analysed cases is, however, still very low, precluding evaluations of the clinical or biological significance of different chromosomal patterns. As part of an ongoing project aiming at identifying clinical-histopathological-cytogenetic correlations among soft tissue tumours, a series of 46 benign, the vast majority of which were located in the extremities, and 20 malignant peripheral nerve sheath tumours (BPNSTs and MPNSTs, respectively) that had been successfully analysed by chromosome banding techniques were evaluated with regard to clinical, morphological, and cytogenetic features. Clonal chromosome aberrations were found in 20 BPNSTs, with abnormal karyotypes being significantly more frequent among Schwannomas than among neurofibromas. Recurrent aberrations, all of which were confined to the Schwannoma subtypes, included loss of 22q material, loss of a sex chromosome, and trisomy 7. The results show that the cytogenetic features of Schwannomas are not dependent on the site of origin. The MPNSTs, all of which had clonal chromosome aberrations, displayed complex karyotypes with numerous structural and numerical changes, except in two cases showing +7 and -22, respectively, as the sole changes. None of the recurrent imbalances was restricted to either NF1-associated or sporadic MPNST, nor was any of the imbalances significantly associated with clinical outcome. The presence of a triploid or tetraploid clone was, however, associated with grade 3 tumours and a poor prognosis. The cytogenetic findings in peripheral nerve sheath tumours show that the karyotype is a good discriminator between BPNSTs and MPNSTs, and that the pattern of aberrations among the latter may add prognostic information.

Adolescent↗
PubMed1998

Abnormal karyotypes in semi-direct chorionic villus preparations of women with different cytogenetic risks.

Among 3499 cytogenetically investigated semi-direct chorionic villus samples, 219 (6.3 per cent) abnormal karyotypes were encountered. The karyotypes were considered certainly abnormal (generalized abnormal with high probability) in 109 cases (3.1 per cent), and in 110 cases (3.1 per cent) uncertainly abnormal (potentially confined to the placenta), requiring further investigation. Of these 110 uncertain abnormalities, the cytogenetic result turned out to be finally abnormal representing generalized abnormality in 36 cases (32.7 per cent), finally normal representing confined placental mosaicism (CPM) in 69 cases (62.7 per cent), and remained undetermined in 5 instances (4.5 per cent). The rate of the numbers of certainly abnormal and all (certainly + uncertainly) abnormal results, the certainty rate, and that of generalized abnormalities and all abnormalities (generalized abnormalities + CPM cases), the predictive value, are strongly correlated with the cytogenetic risk. Therefore, we advise chorionic villus sampling for cytogenetic investigation only in women with a cytogenetic risk equal to or exceeding that of a 40-year-old pregnant woman. Because of the high rate of prenatal follow-up investigations after the finding of uncertain results in semi-direct villi, semi-direct and cultured villi should be karyotyped simultaneously.

Adult↗
PubMed1986

Immunologic and cytogenetic studies improve prognosis prediction in chronic B-lymphocytic leukemia. A multivariate analysis of 24 variables.

Sixty patients with chronic B-lymphocytic leukemia (CLL) were studied. The prognosis predictions achieved from clinical and hematologic status, cytogenetic karyotype, immune phenotype, and cellular proliferative responses in vitro were studied by Cox's multivariate analysis. Indicators of poor survival were high dextran sulphate (DxS)-induced CLL-cell proliferation in vitro (P less than 0.002), older age, low percentage T-cells of blood lymphocytes (P less than 0.01), low hemoglobin count, advanced Binet stage, male sex, and high lymphocyte count (P less than 0.05). A therapy-demanding disease was predicted by cytogenetic data (extra chromosome 12, and complex karyotypes [P less than 0.001]), high DxS-induced CLL-cell proliferation (P less than 0.001), high frequency of cytogenetically abnormal metaphases, and advanced Rai and Binet stages (P less than 0.01). The best combinations of parameters included the cytogenetic variables, the DxS-induced CLL-cell proliferation, the relative T-cell number, and the Binet stage. Thus, results from immunologic and cytogenetic studies seem to be helpful in the prediction of prognosis.

Adult↗
PubMed1994

Primary central nervous system lymphomas. Immunophenotypic, virologic, and cytogenetic findings of three patients without immune defects.

BACKGROUND: Primary central nervous system (PCNS) lymphoma is a relatively rare disease, but an increasing incidence is reported. The Epstein-Barr virus (EBV), which is often found in lymphomas of immunocompromised patients, has been implicated in the development of lymphomas. Many cytogenetic analyses of nodal B cell lymphomas have been performed, but few studies on PCNS lymphomas have been reported. METHODS: The detection of EBV genome using the polymerase chain reaction (PCR) method and cytogenetic studies were performed, in addition to histopathologic and immunophenotypic approaches in biopsied tissue from three patients with PCNS lymphoma. Immunosuppressive states and exposure to mutagens were not clear in all patients. RESULTS: Histopathologic examination disclosed a diffuse type of malignant lymphoma in all patients. Immunophenotypic studies revealed B cell phenotype in all patients, two of whom showed positive reaction for CD5. The PCR method revealed no involvement of EBV genome in tumors in any patients. The cytogenetic study showed clonal chromosome abnormalities in all patients, and abnormalities of chromosome 1 (1q21), 6 (-6, 6q15 and 6q21), 7 (-7 and 7p15), and 14 (14q24 and 14q32) were prominent. The t(6;14)(q15;q32) observed in Patient 1 is the first case to be reported in human de novo lymphoma. CONCLUSIONS: These findings indicate that the causative role of EBV in PCNS lymphoma without immune defects is not clear. The cytogenetic findings were similar to those observed in nodal B-cell lymphoma, suggesting that the origin of PCNS lymphoma cells does not differ from nodal B cell lymphoma cells cytogenetically.

Aged↗
PubMed1994

Cytogenetic findings in 19 malignant bone tumors.

BACKGROUND: The majority of karyotypes observed in osteosarcomas (OS) and chondrosarcomas (CS) are complex. Specific chromosomal abnormalities have not yet been characterized in either tumor except for a ring chromosome in parosteal OS. The purpose of this study was to determine recurrent chromosomal abnormalities and establish a possible correlation between the cytogenetic changes and the pathologic findings. METHODS: Ten OS and nine CS were cytogenetically analyzed. Tumor samples were obtained from patients having a resection or incisional biopsy. Cytogenetic study of short term cell cultures included harvesting and G-banding, which were performed by routine methodologies. RESULTS: Clonal abnormalities were observed in six OS and six CS. Modal chromosome numbers ranged from near diploid to near tetraploid in both types of tumors. The structural rearrangements observed in OS involved mostly chromosomes 1, 2, 6, 12, and 17. Nonreciprocal translocations were the most frequent event. Two OS had a single clonal abnormality involving 11p15 and 14q32, respectively. Double minute chromosomes were observed in three cases. In CS, the most frequent structural abnormalities were nonreciprocal translocations and deletions involving numerous chromosomes. Rearrangements of 1p together with other abnormalities were observed in four CS. CONCLUSIONS: The karyotypes were usually complex consisting of numerical and structural changes, particularly in high grade tumors. Rearrangements of 11p15 and 14q32 in OS and possibly 1p in CS were found as primary cytogenetic aberrations. Cytogenetic analysis in more cases of OS and CS together with molecular studies are necessary to characterize further the consistent genetic changes in these tumors.

Adolescent↗
PubMed1995

Molecular cytogenetic analysis of monosomy 7 in pediatric patients with myelodysplastic syndrome.

Monosomy 7 is a non-random cytogenetic abnormality that is frequently associated with myelodysplastic syndromes (MDS). Twenty-four bone marrow samples from five pediatric patients with MDS were analysed using both traditional and interphase cytogenetic analysis. The majority of the metaphases were monosomic for chromosome 7 while interphase cytogenetic analysis consistently detected a disomic cell population in nondividing cell populations. This suggests that the monosomy 7 cells have a distinct proliferative advantage compared to the disomic cell population. The results demonstrate that interphase cytogenetic analysis provides important cytogenetic information about non-dividing cell subpopulations, enhancing our understanding of the cell dynamics of normal and monosomy 7 cells in MDS.

Adolescent↗
PubMed1980

Utility and limitations of chromosome banding in pre- and postnatal service cytogenetics.

This report analyzes detection rates of chromosome aberrations as a function of stainig technique. Of 1,717 peripheral lymphocyte cultures processed by a midsize service cytogenetics laboratory, 23 chromosomal aberrations (1.3%) would not have been detected without the use of either R-banding or G-banding. These 23 cases comprise 21 of 64 non-Robertsonian structural autosomal changes and two of 68 gonosomal aberrations. In contrast, in 1,634 amniotic fluid cell cultures only one balanced rearrangement (0.06% of all cases) would not have been detected without banding. Combined with incidence rates from newborn cytogenetic screenings, these figures suggest that among 10,000 prenatal diagnoses for advanced maternal age, at most one chromosomally unbalanced fetus would be missed if banding were not routinely applied. Because of savings in time and possible automation, it is estimated that discretionary rather than routine use of chromosome banding in prenatal cytogenetics would allow for detection of at least twice as many age-related aneuploidies. In view of sharply rising demand for prenatal cytogenetic services, a discretionary approach might therefore assure a more equitable distribution of limited cytogenetic resources.

Adult↗
PubMed1994

Comparison between the cytogenetic test for fragile X and the molecular analysis of the FMR-1 gene in Japanese mentally retarded individuals.

The prevalence of the fragile X syndrome has been estimated by the results of population studies in which the disease was mostly diagnosed by cytogenetic examinations. To examine the reliability of the cytogenetic analysis for the estimation of the prevalence of the fragile X syndrome, the CGG repeat in the FMR-1 gene was assayed by Southern blot hybridization and polymerase chain reaction (PCR) in an institutionalized group of mentally retarded individuals consisting of 305 males and 129 females. The data thus obtained were compared with the cytogenetic data. The DNA analysis detected 7 full mutations among the alleles of the 296 unrelated males and 2 full mutations among the alleles of the 129 unrelated females. These findings were consistent with the cytogenetic data. No premutation was found in 554 X chromosomes in the unrelated mentally retarded patients nor 826 X chromosomes in unrelated control individuals. The distribution of the CGG repeat number in the normal range was not significantly different between the mentally retarded individuals and the control individuals. These data suggest that the estimates of the prevalence of the fragile X syndrome based on cytogenetic data in the population studies are almost reliable. Based on the finding that no premutations were found in this study, a small difference in the prevalence of the fragile X syndrome between Caucasians and Japanese is suggested.

Adolescent↗
PubMed2005

Prognostic diversity among cytogenetic abnormalities in myelofibrosis with myeloid metaplasia.

BACKGROUND: Approximately 30-50% of patients with myelofibrosis with myeloid metaplasia (MMM) demonstrate detectable cytogenetic abnormalities, the prognostic value of which has not been completely defined by previous retrospective studies. The current prospective study addresses this issue in the context of currently accepted independent prognostic variables. METHODS: The current study is a single institution study in which patients with MMM were accrued between January 2000 and August 2001 and followed in a prospective fashion. All study patients underwent bone marrow examination with cytogenetic studies as well as comprehensive clinical and laboratory evaluation at the time of karyotype analysis. RESULTS: Among the study cohort of 81 patients (with a median age of 61 years; 54 males), the cytogenetic findings were normal in 44 patients (54%; Group 1). The remaining 37 patients (46%) demonstrated either interstitial deletions involving the long arm of chromosome 13 or 20 (9 patients; Group 2) or other abnormalities (28 patients; Group 3). All study patients were followed prospectively for a minimum of 40 months (range, 40-55 months). Survival from the time of karyotypic analysis was found to be similar between Groups 1 and 2 but was significantly worse in Group 3. Furthermore, none of the patients in Group 2 experienced leukemic transformation, whereas five patients each from the other two groups did. Multivariate analysis identified an unfavorable cytogenetic profile (Group 3), > or = 1% circulating blasts, a hemoglobin level of <10 g/dL, and constitutional symptoms as adverse prognostic features for overall survival. CONCLUSIONS: Specific cytogenetic lesions in patients with MMM might carry an independent prognostic effect for both survival and the risk of leukemic transformation. Such information should assist in decision making when considering aggressive treatment approaches.

Adult↗
PubMed2005

Cytogenetic manifestations of multiple myeloma heterogeneity.

To investigate the genetic basis of the great heterogeneity observed in the clinical behavior of multiple myeloma (MM), a combined approach of G-banding, interphase fluorescence in situ hybridization (FISH), and multicolor FISH (M-FISH) was employed to analyze 70 samples from 53 patients with MM. G-banding revealed abnormal karyotypes in 77% of the cases. The origin of 31 chromosome markers was identified or revised by M-FISH. Combined metaphase karyotypic data and interphase FISH findings, using the immunoglobulin heavy-chain (IGH), IGH/cyclin D1 gene (CCND1), and D13S319 probes, revealed chromosome abnormalities in all evaluated patients and marked inter- and intratumor cytogenetic heterogeneity in the investigated MM samples. Cytogenetically unrelated clones were detected in 26% of the cases, mostly MM evaluated at diagnosis, whereas cytogenetic clonal evolution, manifested as related clones in 20% of the cases, was associated with disease progression. Among the 14q32 rearrangements, present in 66% of the cases, at least three cytogenetic subsets could be identified: one with t(11;14), usually without 13q14 deletion; another with other IGH changes, often 13q14 deletion, and hypodiploid modal chromosome number; and a third without changes in 14q32 but with abnormalities of chromosome 17. The correlation found between cytogenetic and clinicopathologic characteristics provided support for the concept that general genomic features in conjunction with specific chromosome rearrangements define the malignant phenotype in the various subsets of MM.

Adult↗
PubMed2005

Cytogenetic alterations in nonmelanoma skin cancer: a review.

Since the advent of cytogenetic analysis, knowledge about fundamental aspects of cancer biology has increased, allowing the processes of cancer development and progression to be more fully understood and appreciated. Classical cytogenetic analysis of solid tumors had been considered difficult, but new advances in culturing techniques and the addition of new cytogenetic technologies have enabled a more comprehensive analysis of chromosomal aberrations associated with solid tumors. Our purpose in this review is to discuss the cytogenetic findings on a number of nonmelanoma skin cancers, including squamous- and basal cell carcinomas, keratoacanthoma, squamous cell carcinoma in situ (Bowen's disease), and solar keratosis. Through classical cytogenetic techniques, as well as fluorescence-based techniques such as fluorescence in situ hybridization and comparative genomic hybridization, numerous chromosomal alterations have been identified. These aberrations may aid in further defining the stages and classifications of nonmelanoma skin cancer and also may implicate chromosomal regions involved in progression and metastatic potential. This information, along with the development of newer technologies (including laser capture microdissection and comparative genomic hybridization arrays) that allow for more refined analysis, will continue to increase our knowledge about the role of chromosomal events at all stages of cancer development and progression and, more specifically, about how they are associated with nonmelanoma skin cancer.

Chromosome Aberrations↗
PubMed1987

Cytogenetic technique for mouse metaphase II oocytes.

The acquisition of cytogenetic data from mammalian oocytes has required considerable time and expense, since only a relatively small number of oocytes could be processed from three to four animals daily. The availability of a procedure that would facilitate fixation and preparation of air-dried slides from 25-30 superovulated mice within a 3-h period would enhance development of germ cell cytogenetic data by reducing technician time and animal maintenance expense. We present such a procedure for mouse metaphase II oocytes. Mice were superovulated and the oocytes collected were fixed en masse prior to making air-dried slides. Chromosomes were subsequently C-banded to enhance objective cytogenetic analysis. The reliability of the procedure was determined by harvesting 44,814 oocytes from 1,875 mice over a 9-month period and calculating the proportion of cells cytogenetically analyzed to those not analyzed. Cytogenetic analysis of oocytes is an assay for chemicals (and other agents) capable of inducing numerical and structural chromosomal aberrations.

Animals↗
PubMed1993

Cytogenetic evolution in primary tumors, local recurrences, and pulmonary metastases of two soft tissue sarcomas.

The karyotypic pattern at different stages of tumor development may provide information on tumor progression but few data are available regarding human solid tumors. Cytogenetic analysis was performed on the primary tumor and four lung metastases of a synovial sarcoma, and the primary tumor, two consecutive local recurrences, and six pulmonary metastases, obtained at two different occasions, of a malignant fibrous histiocytoma (MFH). Simultaneous existence of more than one cytogenetically aberrant clone was also assessed through analysis of more than one sample from the same surgical specimen. Clonal chromosome aberrations were detected in all samples from the synovial sarcoma, and in both local recurrences and five of the metastases from the MFH. All clones in both tumors were cytogenetically related. The primary synovial sarcoma tumor contained two clones, one of which was also found in the lung metastases, together with a third clone that had acquired additional aberrations. Four clones with a near-tetraploid chromosome number and complex aberrations were identified in the MFH. Likely evolutionary pathways could be deduced in both cases. In the patient with synovial sarcoma one of the pulmonary metastases, rather than the primary tumor, might well have been the source of another of the pulmonary metastases. In the MFH the cytogenetic findings indicated the presence of two co-existing lineages in the primary tumor, one giving rise to the local recurrences and one to the pulmonary metastases. Our findings show that cytogenetic analysis can be used to establish the chronologic relationships between different clones in primary tumors, local recurrences and distant metastases, to determine what genetic changes are of importance for the metastatic capability of tumor cells, and to help establish the origin of the metastatic lesions.

Chromosome Aberrations↗
PubMed1995

Interphase cytogenetics on paraffin-embedded sections of ovary for detection of genomic constitution in a patient with Turner's syndrome and chromosomal mosaicism.

The difficulty of detecting sex chromosome mosaicism cytogenetically hinders the finding of an acceptable explanation for phenotypic-genotypic discrepancy amongst those patients. Fluorescence in situ hybridization (FISH) permits the genomic identification of patients with mosaic karyotypes in interphase nuclei by utilising an X chromosome-specific DNA probe (interphase cytogenetics). We evaluated the efficiency of interphase cytogenetics in the detection of the genomic constitution of the ovary from a patient with Turner's syndrome having mosaicism (46,XX/45,X0) previously established by blood lymphocyte karyotyping. We used a biotin-labelled alphoid repetitive sequence, pBAMX5, specific for the centromeric region of the human X chromosome. Although examination of ovarian sections and blood lymphocytes by FISH showed the presence of both 46,XX and 45,X0 cell lines, the genomic constitution of the germ cells/oocytes in ovarian primordial follicles was shown to be normal (46,XX). Our results (1) show the high applicability of interphase cytogenetics on paraffin sections, (2) indicate the possibility of genomic screening of different tissues that are otherwise not amenable to routine cytogenetic investigation and (3) offer a reliable methodological approach to defining accurate by the percentage of abnormal karyotypes in mosaicism of different organs and non-dividing tissues.

Adult↗
PubMed1979

Genetic and cytogenetic studies of four glycolytic enzymes in Drosophila melanogaster: aldolase, triosephosphate isomerase, 3-phosphoglycerate kinase, and phosphoglucomutase.

Four glycolytic enzymes in Drosophila melanogaster have been genetically and/or cytogenetically mapped. The structural gene for aldolase (Ald) has been genetically mapped to 3-91.5 and cytogenetically localized to 97A-B. Tpi, the structural gene for triosephosphate isomerase, has been genetically mapped to 3-101.3 and cytogenetically localized to 99B-E. Utilizing closer-flanking markers than the previous mapping, Pgk, the structural gene for 3-phosphoglycerate kinase, has been mapped to 2-5.9; cytogenetically it was found to lie in the interval between 22D and 23E3. The cytogenetic locataion of Pgm, the structural gene for phosphoglucomutase which has been located genetically at 3-43.4, was determined to be in 72D1-5.

Alleles↗