Myeloproliferative disorders: II CML: clonal evolution and its role in management.
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Adult↗
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Results for “karyotype evolution”
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Cytogenetic evolution and clonal proliferation in acute transformation of chronic granulocytic leukaemia.
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Bone Marrow↗
Cytogenetic studies in Fanconi's anemia. Description of a case with bone marrow clonal evolution.
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Abnormalities, Multiple↗
Qualitative analysis of chromosomal evolution in a colcemid-treated Chinese hamster population.
Colcemid is known to inhibit the spindle formation and to induce polyploidy and chromosomal nondisjunction. Using a V79 Chinese hamster cell line, we have shown that colcemid is able to induce the formation of cells that are numerically diploid but whose karyotype, when analyzed with the G-banding technique, differs from that of the untreated ones. Even though these cells have a normal chromosomal constitution, they carry alterations in the chromosomal balance and, consequently, in gene dosage. This could result in an abnormal expression of cellular genes or in the expression of new or preexisting recessive mutations, even in a diploid chromosomal constitution.
Aneuploidy↗
Chromosome 12 rearrangement with breakage at the p11 level in hematologic disorders: report of four cases.
Four patients with chromosome #12 rearrangement at the p11 level are described. One had acute promyelocytic leukemia, one had myelofibrosis evoluting to acute undifferentiated leukemia, one had acute nonlymphoid leukemia (ANLL) secondary to Hodgkin's disease, and another had acute leukemia recurring after allogeneic bone marrow transplantation. This chromosome abnormality was always associated with other karyotypic aberrations, probably as a secondary event. Possible correlations with recent findings in oncogene research are discussed.
Adult↗
Karyotypic variation between independently cultured strains of the cell line MCF-7 identified by multicolour fluorescence in situ hybridization.
The breast cancer cell line MCF-7 is a widely used model in breast cancer research however a number of conflicting reports have been published regarding its biological properties. We hypothesised that there will be significant in vitro mutation and genotypic evolution over time in this cell line. To assess the genetic divergence of MCF-7 at the chromosomal level, we analysed MCF-7 cell lines grown independently at three different laboratories using M-FISH and CGH. In addition, MCF-7 cells from our own laboratory were also analysed at two time points 18 months apart. Several common chromosomal translocations were identified in all variants of the cell lines. In addition, a significant number of unique abnormalities were identified, characterising each of the variants studied. Genotypic differences between cell lines grown independently in different laboratories would significantly alter the phenotypic characteristics of each cell line rendering biological properties inconsistent between laboratories.
Breast Neoplasms↗
Clonal evolution from trisomy into tetrasomy of chromosome 8 associated with the development of acute myeloid leukemia from myelodysplastic syndrome.
Tetrasomy 8, though rare, is usually associated with trisomy 8, a far more common chromosomal abnormality in acute myeloid leukemia (AML). Yet the clonal relationship between trisomy 8 and tetrasomy 8 in the cases with these chromosomal abnormalities has been unclear. Here, we report a case of a 17-year-old male, diagnosed as having a myelodysplastic syndrome (MDS). Chromosome analysis showed the presence of trisomy 8. Five years later, he developed overt AML exhibiting tetrasomy 8 only. After chemotherapy, the blast cells in the bone marrow decreased to 3.4%, and the karyotype showed trisomy 8 alone. Fluorescence in situ hybridization using a probe specific for chromosome 8 showed that the percentages of cells exhibiting 2/ 3 /4 signals were 7.8/89.2/2.0 at the MDS stage, 20.5/36.1/41.0 when overt AML developed and 24.0/72.1/2.4 after chemotherapy. These results suggested that tetrasomy 8 is derived from the AML clone, possibly evolved from the MDS clone with trisomy 8. To our knowledge, this is the first detailed case report of clonal evolution from trisomy 8 into tetrasomy 8 associated with the development of AML from MDS.
Adolescent↗
Phylogenetic history of the Sifakas ( Propithecus: Lemuriformes) derived from cytogenetic studies.
The R-banded karyotypes of the different subspecies of Propithecus diadema and P. verreauxi are compared to each other and to that of P. tattersalli, as well as those previously reported of Indri indri and Avahi laniger. This comparison shows that the different subspecies of P. verreauxi possess the same karyotype and that, among P. diadema, P. d. diadema and P. d. perrieri share the same karyotype differing from that of P. d. edwardsi by one Robertsonian translocation. The karyotype of P. tattersalli differs at least through 17 and 9 rearrangements from those of P. diadema and P. verreauxi, respectively. This provides strong arguments in favor of its specific status. The phylogenetic diagram proposed confirms the early separation of Avahi and the relatively late divergence of the four other species. A populational evolution has occurred between these four species, P. tattersalli and P. verreauxi sharing the largest number of rearrangements (six), while the numbers of rearrangements shared by the other species are two for Indri and P. verreauxi, three for P. tattersalli and Indri, and three for P. tattersalli and P. diadema. No branch is common to two species of Propithecus.
Animals↗
Multiple chromosome abnormalities in a drug resistant TdT positive B-cell leukemia.
A 17-year old caucasian male presented with B-cell acute leukemia which proved aggressive and refractory to treatment. Cytogenic investigation showed a single clone with a complex karyotype 49,XY,del(2)(p13),+4,del(4)(p11),-6,+i(6)(p),+7,+8, t(8;14), (q24;q32),del(17)(p11). This includes the Burkitt's translocation and a deletion at the site of the immunoglobulin kappa light chain gene. Clonal evolution included tetraploidy, duplication of the derived chromosomes and, terminally, trisomy 1q. Immunological investigation revealed a monoclonal population of B-cell blasts, expressing the kappa light chain, and with an extremely rare combination of SIg and TdT positivity. Immunoglobulin gene rearrangement confirmed monoclonalility. Tetraploidy of the clone and del(17)(p11) have been previously described only in a cell line or at end stage disease in B-ALL. It is suggested that the chromosomal abnormalities present at diagnosis were directly related to the refractory nature of this leukemia.
Acute Disease↗
Cytogenetic studies of 21 patients with acute lymphoblastic leukemia in relapse.
Karyotypes of 21 patients, originally entered into the Third International Workshop on Chromosomes in Leukemia (3IWCL), were investigated in first, second and/or subsequent relapses. Karyotypes at diagnosis were related to the relapses in the following ways: normal to normal (N-N) (five cases); abnormal to normal (A-N) (two cases); abnormal to abnormal with no change (A-A) (five cases); abnormal to abnormal with clonal evolution (A-A+) (eight cases); and normal to abnormal (N-A) (one case). The A-A group comprised two each of t(4;11) and t(9;22) cases and one pseudodiploid case; included in this group were the only two patients who did not receive intensive treatment. Both A-N cases had been pseudodiploid at diagnosis. Clonal evolution A-A+ occurred in patients who had had 47-49 chromosomes or pseudodiploidy at diagnosis and was mainly due to the addition of structural change. The additional abnormalities were different in each case. The only de novo appearance of a clone (N-A) was in host cells in relapse following bone marrow transplantation. Clonal evolution occurred in patients who had been intensively treated and who relapsed late; the median time from diagnosis to relapse studied for the A-A group was 6 months and for the A-A+ group was 24 months. Survival following relapse was shorter for patients who had had a clonal abnormality at any time (median 10 months) than for those with no abnormality at diagnosis or in relapse (median 26 months).
Adolescent↗
Chromosome banding in Amphibia. VIII. An unusual XY/XX-sex chromosome system in Gastrotheca riobambae (Anura, Hylidae).
The mitotic and meiotic chromosomes of the marsupial frog Gastrotheca riobambae were analysed with various banding techniques. The karyotype of this species is distinguished by considerable amounts of constitutive heterochromatin and unusual, heteromorphic XY sex chromosomes. The Y chromosome is considerably larger than the X chromosome and almost completely heterochromatic. The analysis of the banding patterns obtained with GC- and AT-base-pair-specific fluorochromes shows that the constitutive heterochromatin in the Y chromosome consists of at least three different structural categories. The only nucleolus organizer region (NOR) of the karyotype is localized in the short arm of the X chromosome. This causes a sex-specific difference in the number of NOR: female animals have two NORs in diploid cells, male animals one. No cytological indications were found for the inactivation of one of the two X chromosomes in the female cells. In male meiosis, the heteromorphic sex chromosomes form a characteristic sex-bivalent by pairing their telomeres in an end-to-end arrangement. The significance of the XY/XX sex chromosomes of G. riobambae for the study of X-linked genes in Amphibia, the evolution of sex chromosomes and their specific DNA sequences, and the significance of the meiotic process of sex chromosomes are discussed.
Animals↗
Patterns of chromosome breakage in nonHodgkin lymphoma: significance to gene alteration in tumorigenesis.
In a comprehensive cytogenetic analysis of nonHodgkin lymphoma (NHL) that was based on a database derived from karyotypic descriptions of 264 tumors, we previously established correlations between specific chromosome changes and histologic subtypes of lymphoma. In the present paper we analyze the total chromosome breakage encountered in this group of tumors. This analysis permitted distinction between sites of nonrandom breakage that are specific for lymphoid tumors (and hence of probable primary or etiologic significance) and sites of nonrandom breakage that are common to lymphoid as well as nonlymphoid tumors (and hence of probable secondary or evolutionary significance). We also observed that breakage affected all of the immunoglobulin and T cell receptor gene sites and most of the known cellular oncogene and fragile sites; however, only a limited number of these sites exhibited statistically significant breakage. Of special interest was the fact that the fragile sites that exhibited significant breakage were mostly those that also were sites of cellular oncogenes. Our data suggest that breakage at sites of immunoglobulin genes and a limited number of cellular oncogenes alone is of importance in B-cell lymphomagenesis. While the timing or causes of genomic destabilization in tumorigenesis are unknown, recent molecular analysis of junction regions of chromosome rearrangements designated here as primary translocations has suggested that more than one mechanism may be involved in their generation. This study identifies chromosomal sites of nonrandom perturbation that may be targeted for detailed molecular analysis aimed at understanding the origin, evolution, and spread of B-cell NHL.
Chromosome Aberrations↗
Mitotic karyotyping and FISH mapping of the gender-specific locus indicate an advanced XY system in Hippophae rhamnoides.
Hippophae rhamnoides ssp. turkestanica, a subdioecious plant inhabiting the cold desert of the Indian Himalaya, has gained immense recognition for its nutritional and medicinal values. In recent years, the plant species has proven to be a suitable system to understand the evolution of dioecy. Despite its biological significance, the cytogenetics of this dioecious plant is unclear due to various conflicting accounts of its X-Y chromosome system, particularly the length of Y-chromosome. In this study, we resolved these ambiguities through comprehensive cytogenetic analyses across diverse western Himalayan populations. Using morphometric analysis and fluorescence in situ hybridization (FISH) with a gender-specific marker (HRMSSR), we confirmed homomorphic XX chromosomes in females and heteromorphic sex-chromosomes in males with a notably smaller Y-chromosome. The investigation also revealed a predominant somatic chromosome number of 2n = 24, although minor deviations (2n = 18, 20, 22) appeared at the seed level. These findings highlight an evolutionarily advanced sex-chromosome system. This first detailed cytogenetic investigation of Himalayan Seabuckthorn provides critical insights into the chromosomal architecture, laying a crucial foundation for future evolutionary, genomic, and conservation studies in the species.
Chromosome Mapping↗
Cytogenetic evolution patterns in non-Hodgkin's lymphoma.
Secondary chromosomal aberrations were surveyed in non-Hodgkin's lymphomas (NHL) reported in the literature with one of the following, presently recognized, primary abnormalities: t(2;5), +3, t(3;14), del(6q), +X, and -Y. Of 2,175 NHLs with clonal karyotypic changes, 908 (42%) had one of the 13 selected primary chromosome rearrangements, and 670 (74%) of these lymphomas displayed additional abnormalities. The type and frequency of the secondary aberrations were ascertained and then correlated with both the type of primary abnormality and morphologic subtype; low-, intermediate, and high-grade according to the Working Formulation. The incidence of secondary aberrations differed not only among the primary abnormality subgroups, from 0% in del(11q) NHLs to 93% in t(3;14) lymphomas (P < .001) but also between B- and T-cell NHLs (78% versus 55%, P< .001) and among the different histologic subgroups: 66% in low-, 85% in intermediate-, and 71% in high-grade lymphomas (P < .001). The mean number of secondary changes per case also varied among the primary abnormalities, from none in del(11q) NHLs to 12.0 in inv(14) lymphomas (P < .001), and among the morphologic subtypes: 4.6 in low-, 6.7 in intermediate-, and 3.6 in high-grade NHL (P < .001). Recurrent secondary aberrations were found in 6 of the 13 primary abnormality subgroups: t(2;5), t(3;14), t(8;14), t(11;14), inv(14), and t(14;18). The most frequent secondary aberrations were +X, -Y, dup(1q), del(6q) varied both within and among the primary abnormalities; the most frequent imbalances were a gain of 1q23-31 and losses of 6q21, 6q23, and 6q25. Other common imbalances were deletions of 1p31-36, 1q31-44, 2q34-37, 7q35-36, 9p22-24, 11q23-25, 13q13-21, and duplication of 12q13-22. The distribution of the secondary changes was clearly nonrandom with the most common anomalies being -Y and +7 in t(2;5); +X, del(6q), and +7 in t(3;14); dup(1q) and +7 in t(8;14); -Y, del(6q), and -13 in t(11;14); del(6q), -17, and -18 in inv(14); and del(6q), +7, and +12 in t(14;18) NHLs. In general, the secondary aberrations were similar in lymphomas of different histologic subtypes but with the same primary abnormality, although some significant differences were discerned: +3, del(6q), +7, and +18 wee more common (P < .01) in intermediate-grade than in high-grade t(8;14) NHLs; monosomy 13 occurred only in intermediate-grade t(11;14) NHLs (P < .05); and +7 and t(8;14)/t(8;22) were more frequent (P < .01 and P< .001, respectively) in high-grade than in low- and intermediate-grade t(14;18) NHLs.(ABSTRACT TRUNCATED AT 400 WORDS)
Chromosome Aberrations↗
Mapping the distribution of the telomeric sequence (T(2)AG(3))(n) in rock wallabies, Petrogale (Marsupialia: Macropodidae), by fluorescence in situ hybridization. ii. the lateralis complex.
The distribution of the conserved vertebrate telomeric sequence (T(2)AG(3))(n) was examined by fluorescence in situ hybridization in the six Petrogale (rock wallabies) taxa of the lateralis complex. As expected, the (T(2)AG(3))(n) sequence was located at the termini of all chromosomes in all taxa. However, the sequence was also present at several nontelomeric (viz., interstitial and centromeric) sites. The signals identified were associated with either ancient rearrangements involved with the formation of the 2n = 22 plesiomorphic macropodine karyotype or more recent rearrangements associated with karyotypes derived from the 2n = 22 karyotype. Interstitial (T(2)AG(3))(n) signals identified on chromosomes 3 and 4 in all six species of the lateralis complex and a large centromeric signal identified on chromosome 7 in the five subspecies/races of P. lateralis appear to be related to the more ancient rearrangements. Subsequent chromosome evolution has seen these signals retained, lost, or amplified in different Petrogale lineages. Within the lateralis complex, in two submetacentric chromosome derived by recent centric fusions, the telomeric sequence was identified at or near the centromere, indicating its retention during the fusion process. In the two taxa where chromosome 3 was rearranged via a recent centromeric transposition to become an acrocentric chromosome, the telomeric signal was located interstitially.
Animals↗
Chromosomal biomarkers in the clonal evolution of head and neck squamous neoplasia.
The biological behavior of any tumor is the result of changes in gene expression caused by mutations accumulated in the carcinogenic process. In squamous carcinoma of the head and neck (SCCHN) there are numerous complex chromosome abnormalities. To make sense of this complexity it is necessary to identify the consistent chromosome changes in a large panel of tumors, to determine if these changes are true representations of the in vivo situation, and to construct a map of gene loci likely to be involved in the development and progression of cancer. Our findings indicate that cultured tumor cells are cytogenetically stable when compared to cells evolving in vivo. We also found that clues to the sequence of events in clonal evolution of individual tumors can be deduced by studying primary and metastatic tumors from the same patient, by examining separate clones within the same tumor, and by analyzing ploidy changes. Furthermore, comparison of the in vitro karyotypes to in situ analysis of the tumor tissue indicates that in vitro cultures are good representations of the in vivo tumor. We conclude that identification of consistent chromosome changes in cultured cells can lead to the loci of genes important in the clinical behavior of individual tumors. The most frequent chromosome abnormalities in SCCHN, found in 40-60% of tumors, are deletions affecting 3p, 5q, 8p, 9p, and 18q. Less common consistent changes found in 30-40% of tumors are gains affecting 3q, 5p, 7p, 8q, and 11q. Preliminary evidence suggests that loss of 18q may be prognostically important and may involve disruption of genes encoding cell adhesion molecules.
Carcinoma, Squamous Cell↗
DNA reassociation kinetics in diploid and phylogenetically tetraploid cyprinidae.
Four diploid and three phylogenetically tetraploid Cyprinidae (Ostariophysi) have been characterized as for nuclear DNA content, modal chromosome number and DNA reassociation kinetics (hydroxyapatite chromatography). Among the diploid species nuclear DNA content (10(-12) g DNA/2C) was 1.62 for Tinca tinca, 1.87 for Scardinius erythrophthalmus, 2.53 for Leuciscus cephalus and 2.75 for Alburnus alburnus, while the phylogenetically tetraploid species Carassius auratus, Barbus barbus and Cyprinus carpio attained 3.40, 3.66 and 3.80 respectively. Modal chromosome number was 2n = 48-50 for diploid individuals and 2n = 100-104 for phylogenetically tetraploid ones. In all the species 5--8% of the genome is represented by highly repetitive and foldback DNA. In DNA reassociation kinetics of phylogenetically tetraploid Cyprinidae a distinct plateau separates an intermediate reassociating sequence fraction (about 22% of the genome; with average repetition frequencies between 1,000 and 1,400) from a slow reassociating one (unique DNA; about 72% of the genome). These two genome fractions are not clearly distinguishable from each other in Cot curves of the diploid Cyprinidae, where a similar plateau is not evident. Since simple ploidy changes are not expected to affect DNA reassociation kinetics we suggest a different evolution in the genome organization of the two ploidy groups. Some possible hypotheses are discussed.
Animals↗
Chromosomes, DNA sequences, and evolution in salamanders of the genus Plethodon.
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Animals↗