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Abnormalities of chromosomes 7 and 22 in human malignant pleural mesothelioma: correlation between Southern blot and cytogenetic analyses.

Southern blot hybridization studies were performed on 23 mesothelioma primary tumor specimens to detect chromosome 1-, 7-, and 22-specific numerical changes, gene amplifications, and gene rearrangements. The molecular findings were compared with previous cytogenetic findings. No gene rearrangements or amplifications were detected. A numerical abnormality of chromosome 7 was detected by Southern blot analysis in two cases in which no numerical abnormality had been detected by the previous chromosome study. A numerical aberration of chromosome 22 was detected in five cases, which was compatible with the cytogenetic finding of monosomy 22 in these cases. The Southern blot results for the copy numbers of chromosomes 7 and 22 were concordant with the cytogenetic findings in 65%-80% of the cases.

Blotting, Southern↗

Cytogenetic abnormalities in non-small cell lung carcinoma: similarity of findings in conventional and feeder cell layer cultures.

Primary tumors from 39 patients with non-small cell lung carcinoma (NSCLC) were examined for cytogenetic abnormalities by conventional short-term harvest (1-39 days) of primary cultures of minced solid-tumor tissues and by harvest of monolayer cultures of tumor tissue (6 days to 5 months) on murine fibroblast feeder layers. A successful karyotype was obtained with both methods in nine of 39 cases. Among the remaining 30 cases, a successful karyotype was obtained in eight cases by the conventional method only and in three cases by the feeder cell method only. The success rates were 44% for the conventional method, and 31% for the feeder cell method, and the combined success rate was 51% for one or the other method. The feeder culture method, in which harvests were usually performed at later times than with the conventional method, generally produced metaphases with superior banding, which allowed clearer definition of cytogenetic abnormalities. In addition, cell lines were established in eight of these cases by the feeder cell method. Karyotypes from the longer-term harvests typically were very similar to those from short-term conventional cultures. Minor numerical differences and/or a few additional structural abnormalities were noted in seven of the nine cases analyzed by both methods. Overall, however, even in karyotypes from 5-month cultures, the prominent recurrent changes and modal chromosome numbers observed in short-term cultures were still present. The results indicate that long-term culture with fibroblast feeder cells is a valid means of obtaining cells from solid lung tumors for cytogenetic and molecular analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Cytogenetic deletion maps of hematologic neoplasms: circumstantial evidence for tumor suppressor loci.

Research in oncogenetics has led to the identification of two major classes of tumor-associated genes, oncogenes and tumor suppressor genes. In a wide variety of solid tumor types, mutations of both groups of genes have been implicated in the tumorigenic process. In hematologic neoplasms, on the other hand, most attention has focused on illegitimate activation of oncogenes, e.g., deregulation leading to disturbed transcriptional activity and structural rearrangements resulting in hybrid genes. Whether loss or mutational inactivation of tumor suppressor genes also plays an essential role in the genesis of tumors of the hematopoietic system has received less attention. Because such inactivation can be the result of karyotypically detectable loss of chromosomal material, cytogenetic studies may prove helpful in pinpointing genomic sites that harbor tumor suppressor genes. The present study is based on a total of 12,473 cytogenetically abnormal hematologic neoplasms reported in the literature to date. Among these, we selected the 6,422 cases with sole clonal chromosomal abnormalities in order to include only aberrations of importance in the genesis, rather than in the progression, of these neoplasms. All tumors with monosomies or structural abnormalities resulting in loss of chromosomal material were compiled, and for every such structural aberration, i.e., deletion, unbalanced translocation, isochromosome, and ring chromosome, the chromosome bands lost were ascertained. This cytogenetic deletion mapping revealed that the most commonly lost chromosomes were Y and 7 in acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and chronic myeloproliferative disorders (MPD); X, Y, 7, 20, and 21 in acute lymphocytic leukemia (ALL); X, Y, and 17 in chronic lymphoproliferative disorders (LPD); and X and Y in non-Hodgkin's lymphoma (NHL). Chromosome segments/bands lost due to unbalanced structural abnormalities in at least 5% of the cases were 5q13-33, 7q22-36, 9q13-31, 11q23-25, 12p12-13, 17p11-13, and 20q11-13 in AML; 5q13-35 and 20q11-13 in MDS; 5q22-23, 7q22, 13q12-22, 17p11-13, and 20q11-13 in MPD; 6q15-27, 9p11-24, 12p12-13, and 19p13 in ALL; 6q16-27, 11q21-25, 13q13-14, and 14q32 in LPD; and 6q21-27, 11q13-25, and 14q24-32 in NHL. Based on these findings, three conclusions can be drawn. First, there is no good correspondence between total and partial monosomies, the only exception being -7 and 7q-, both of which are common in myeloid neoplasms. This indicates different pathogenetic effects of total and partial losses.(ABSTRACT TRUNCATED AT 400 WORDS)

Chromosome Aberrations↗

Molecular cytogenetic analysis of i(12p)-negative human male germ cell tumors.

The i(12p) chromosome has been shown to characterize more than 80% of male germ cell tumors (GCTs) and is an important diagnostic marker. Although recent cytogenetic analyses of GCTs have defined nonrandom chromosome abnormalities in these tumors, no attempt has so far been made to compare i(12p)-positive and -negative tumors in terms of their cytogenetic, histologic, and clinical features. During a 5-year period, we have ascertained 202 GCTs, of which 117 had clonally abnormal karyotypes. Among the latter, 91 had one or more copies of i(12p), whereas 26 lacked an i(12p). We report here the karyotypic analysis of these 26 i(12p)-negative GCTs. In this group, nonrandom sites of chromosomal rearrangements included 12p13 (9/26) and 1p11-q11 (5/26). Comparison of the cytogenetic features of i(12p)-negative tumors with i(12p)-positive tumors revealed the only significant difference to be rearrangements affecting 12p13 in the former (35%) as compared to their absence in the latter (3%). Hybridization of metaphase preparations of 9 i(12p)-negative tumors with a chromosome 12 painting probe and with a microdissected 12p painting probe revealed extra copies of chromosome 12 segments incorporated into marker chromosomes whose composition could not otherwise be resolved by banding analysis; all were shown to be derived from 12p. These data demonstrate that both i(12p)-negative and -positive groups are characterized by an increased copy number of 12p, which is consistent with a lack of significant clinical or biological difference between them. An increased 12p copy number thus is a specific aberration of significance to the development of germ cell tumors.

Chromosome Aberrations↗

Cytogenetic and molecular analysis of 6q deletions in Burkitt's lymphoma cell lines.

Although abnormalities of chromosome 6 have frequently been observed in Burkitt's lymphoma (BL), they have so far not been defined by modern cytogenetic and molecular methods. By a combination of high-resolution chromosome banding, fluorescence in situ hybridization (FISH), and loss of heterozygosity (LOH) analysis, we have examined the nature of aberrations affecting chromosome 6 in 7 previously established BL cell lines. All cell lines exhibited the characteristic translocations associated with BL; 5 had t(8;14)(q24;q32) and 2 had t(8;22)(q24;q11). Three cell lines had deletions of 6q; 3 others had rearrangements affecting 6q, whereas one cell line had apparently normal chromosomes 6. FISH analysis of the three deletions established that they were interstitial. LOH analysis with probes mapped to the 6q26-27 region confirmed the sub-telomeric interstitial deletion in cell line BL-108, which had a del(6)(q23q27). All informative loci mapped to 6q26-27 (5/7) were deleted in BL-74, which had no apparent cytogenetic abnormality in chromosome 6, thus documenting a sub-microscopic deletion. These data define the cytogenetic and molecular limits of 6q deletions in BL and are consistent with our previous demonstration of LOH analysis of the site of a candidate tumor suppressor gene in the 6q25-27 region.

Adolescent↗

Detection of numerical and structural chromosome abnormalities in pediatric germ cell tumors by means of interphase cytogenetics.

In contrast to the cytogenetically well characterized testicular germ cell tumors (GCT) in adults, reports on cytogenetic studies in pediatric GCT are scarce. The presence of an i(12p) and numerical abnormalities involving chromosome 12 are the most frequent cytogenetic changes in GCT of adults. We have performed in situ hybridization (ISH) studies on paraffin sections and on isolated nuclei of 13 pediatric GCT with particular emphasis on those chromosome abnormalities that are common in adult GCT. These include numerical and structural abnormalities of chromosomes 1 and 12 as well as numerical deviations of chromosomes 8, 10, X, and Y. The histological subsets of the tumors investigated included two dysgerminomas (DGE), one seminoma (SE), two embryonal carcinomas (EC), four mixed and two pure yolk sac tumors (YST), and one undifferentiated (IT) and one differentiated teratoma (TD). Similar to the GCT in adults, additional copies of chromosome 12 were the most frequently observed numerical abnormalities. In contrast to the findings in adult GCT, changes in the size of the pericentromeric hybridization signals of chromosome 12, suggesting the presence of i(12p) chromosomes, were found in only two cases. No chromosome abnormalities were found in the pure TD or in the TD cells of mixed tumors containing a YST component. In the YST portion, however, Ip deletions and/or numerical chromosome changes were present. Surprisingly, deletions of the short arm of chromosome I, del(I)(p36.3), were frequent in pediatric GCT and were the sole abnormality detected in two cases. The Ip36 deletions were present in all stage-IV EC and YST investigated and were absent in the relatively benign TD and in one YST stage-I. Therefore, Ip36 deletions may have value as a prognostic marker in pediatric GCT.

Adolescent↗

A new cytogenetic subgroup in uterine leiomyoma is characterized by a deletion of the long arm of chromosome 3.

Our cytogenetic findings in 175 uterine leiomyomas revealed 52 tumors with clonal chromosome abnormalities, eight of which did not belong to any well-delineated cytogenetic abnormal subgroup. However, an interstitial deletion of the long arm of chromosome 3 was found, as the sole chromosome abnormality, in three cases. We believe that this involvement of 3q is significant enough to consider it as a new cytogenetic subgroup of uterine leiomyoma.

Adult↗

Massive cytogenetic heterogeneity in a pancreatic carcinoma: fifty-four karyotypically unrelated clones.

Chromosome analysis after short-term culture revealed remarkable cytogenetic heterogeneity in a pancreatic carcinoma. The patient had no prior history of radio- or chemotherapy. A total of 54 aberrant, near-diploid, karyotypically unrelated clones were identified, three of which displayed clonal evolution. The abnormalities were unbalanced in 30% of the clones. From one to eight karyotypic anomalies per clone were found. Numerical changes were rare, whereas structural aberrations were numerous and diverse and included deletions, duplication, insertions, inversions, translocations, ring formation, and telomeric associations. All chromosomes except No. 15 were involved in structural rearrangements, chromosomes 1, 6, 7, 8, 11, and 12 being the most frequently affected. A similarly massive cytogenetic polyclonality has never been reported previously. Although the spectrum of epithelial neoplasms characterized by karyotypically unrelated clones is increasing, the pathogenetic role of this type of cytogenetic intratumor heterogeneity remains unknown.

Aged↗

Cytogenetic analysis of tissues from patients with familial paragangliomas of the head and neck.

BACKGROUND: Paragangliomas of the head and neck are slow-growing tumors that originate from neural crest cells. Between 7% and 9% of these tumors have a familial occurrence. The suspected gene for familial paragangliomas (FP) is transmitted with an autosomal dominant mode of inheritance with incomplete penetrance, and appears to exhibit genomic imprinting. It has been demonstrated by family studies that individuals who inherit the gene(s) from their father will develop the disease. Through linkage analysis, the gene(s) for FP has been postulated to be located on the long arm of chromosome 11. The discovery of many different genes has been elucidated through the cytogenetic analysis of affected individuals who carry specific chromosome aberrations. This project was designed to look for chromosome abnormalities in several second-generation family members to further assist in the localization of the gene(s) for FP. METHODS: This study involved the cytogenetic evaluation of lymphocytes, fibroblasts, and tumor cells of several second-generation family members from a three-generation family with FP of the head and neck to look for chromosome abnormalities generally, and for abnormalities of chromosome 11 specifically. Standard cytogenetic techniques were used for lymphocyte and fibroblast cultures. Tumor cells were cultured in a collagen matrix with F12 medium supplemented with 3% L-glutamine and 10% fetal calf serum. RESULTS: There were no detectable abnormalities of chromosome 11 in any of the cells. However, nonrandom abnormalities of chromosomes 5 and 7 were seen in some of the tumor cells of one FP patient. To our knowledge, this is the first article which demonstrated the ability to successfully culture FP of the head and neck.

Adult↗

Comparative cytogenetic and DNA flow cytometric analysis of 150 bone and soft-tissue tumors.

Samples from 48 benign and 102 malignant bone and soft-tissue tumors were analyzed cytogenetically and by DNA flow cytometry. Clonal chromosome abnormalities were found in 82 tumors and normal karyotypes in 68; 61 tumors were DNA-non-diploid and 89 were diploid. The cytogenetically abnormal tumors were used for comparison between the 2 types of investigation; 45 of these tumors were DNA-diploid and 37 were DNA-non-diploid. There was, with few exceptions, good correspondence between the quantitative estimates of genomic changes by the 2 methods, indicating that the cells cytogenetically analyzed from short-term cultures are representative of the in vivo cell populations. Discrepancies were primarily found in cases with indexes above 1.5, in which the DNA index was higher than the chromosome index. The chromosome analysis suggested that skewed stemline (G0/G1) peaks in the diploid region in DNA histograms indicate the presence of cell populations with small net quantitative genomic changes, although not all such populations were detected by DNA flow cytometric analysis. The view that one of the peaks in bimodal stemline DNA histograms with narrow peaks represents a non-diploid cell population was also corroborated. On average, the cell populations giving rise to double stemlines in DNA histograms showed quantitatively larger genomic changes than those that gave rise to broad or skewed diploid G0/G1 peaks. The findings indicate that these histogram profiles are not artifactual but reflect chromosomal changes in the tumor parenchyma.

Bone Neoplasms↗

Translocation t(9;22)(q22;q12) is a primary cytogenetic abnormality in extraskeletal myxoid chondrosarcoma.

The cytogenetic and in vitro growth characteristics of 3 cases of extraskeletal myxoid chondrosarcoma (EMC) are described. In cell culture, the tumor cells retained the immunocytochemical and ultrastructural characteristics of EMC. Cytogenetically, 2 of the cases showed an apparently identical t(9;22)(q22;q12). In one case, the t(9;22) was found together with a dup(I)(q12q44), and in the other case it was found together with several other aberrations. The third case had an inv(10)(p11.2q22) as the sole karyotypic abnormality. Of 4 cases of EMC previously analyzed, 2 showed a t(9;22)(q22;q11-12) and one case of a t(9;22;15)(q31;q12.2;q25). Thus, 5 out of 7 cases of EMC showed recombination between 9q22-31 and 22q11-12, indicating that this represents a tumor specific abnormality. The breakpoints on 22q were in all 5 cases cytogenetically indistinguishable from those seen in Ewing's sarcoma with t(11;22), clear-cell sarcoma with t(12;22), and desmoplastic small round cell tumors with t(11;22). Molecular cloning of these translocation breakpoints revealed involvement of the EWS gene (located at 22q12) in all 3 tumor types. These observations raise the intriguing question of whether the EWS gene might also be involved in the t(9;22) in EMC.

Aged↗

Cytogenetic diversity in primary human tumors.

Cytogenetic patterns from primary short-term culture of breast cancer, renal carcinoma, and tumors of the central nervous system are presented to illustrate the range of karyotypic diversity of human solid tumors as well as their biologic differences in culture systems that support their growth. These studies have illustrated several major issues. 1) Results vary with the tissue of origin: primary cultures from breast are almost uniformly diploid, while renal tumors are near-diploid, mosaic, and show clonal aberrations; and CNS tumors are heterogeneous: some diploid, some near-diploid and some highly aneuploid. 2) Results after short-term culture are selective, representing subpopulations from the heterogeneous cells that are detected on direct analysis of fresh tumors by cytogenetics or flow cytometry (FCM). It is not yet clear whether prognosis depends on the dominant population of the primary tumor or alternatively should be influenced by detection of small aneuploid subpopulations. 3) Evidence from all three tumor types supports the interpretation that cytogenetically normal diploid cells constitute part of some tumor populations, and may be better adapted to routine growth in culture than aneuploid subpopulations from the same primary tumors. These cells may also compose a major portion of the viable population of tumors in vivo and, therefore, could represent a useful model for studies of tumorigenesis and therapeutic regimens.

Brain Neoplasms↗

Cytogenetic evaluation of human endothelial cell cultures.

Cytogenetic evaluation of serially subcultivated human endothelial cells revealed significant differences between cultures derived from fetal umbilical cords and cultures derived from various vessel sites in adults. A rapid increase in the prevalence of polyploid cells, to levels of 100% in many cases, was detected in human umbilical vein endothelial cell cultures but not in endothelial cell cultures from adult vessels. Because the development of polyploidy has been viewed as one signpost of in vitro senescence, it may be that these in vitro observations of high levels of polyploidy are a reflection of the fact that umbilical tissue is at the end of its in vivo developmental lifespan when studied. Consistent karyotypic alterations also were observed in two clones from adult human abdominal aorta, even though these cultures exhibited low percentages of polyploid cells. Cultures of one clone exhibited a trisomy of chromosome 11, on which there are at least three onc gene loci, and a deletion of chromosome 13 through band q14. A loss of band 13q14 is a prezygotic chromosomal lesion known to predispose to retinoblastoma. In the other clone, two cell populations were observed, and each displayed a chromosomal abnormality. A trisomy of the long arm of chromosome 2 was noted in one cell population via a marker chromosome involving 2 and 14. The other cell population exhibited an abnormality of chromosome 2. Neither of these karyotypic alterations was detected in the parent culture from which the clones were derived. The results reported in this study have both practical and theoretical implications. The high incidence of polyploidy in serially cultivated umbilical cultures as well as the occurrence of chromosomal changes in umbilical and aortic cultures testify to the need for cytogenetic monitoring of cell cultures even though they are derived from presumably normal tissue. Cytogenetic changes in the endothelium may be important in atherogenesis and other pathologic states. The conversion of diploid endothelial cells into polyploid endothelial cells may provide a convenient model cell system for studying mechanisms of the development of polyploidy in cells and their relationship to in vitro senescence.

Adult↗

Acute megakaryoblastic leukemia in Down's syndrome: report of a case and review of cytogenetic findings.

A case of a child with trisomy 21 and acute megakaryoblastic leukemia (AMBL) is reported. Histological examination of the bone marrow showed progressive fibrosis and replacement with megakaryoblasts. The diagnosis was confirmed by platelet peroxidase reaction and immunofluorescent staining with anti-factor VIII. Serial cytogenetic studies using banding techniques at various stages during the course of the disease (preleukemia, leukemia, remission, and relapse) showed several chromosomal abnormalities (unbalanced translocation between chromosomes 1 and 4 leading to trisomy 1q, trisomy 7q, monosomy 7p, and a reciprocal translocation between chromosomes 10 and 16). AMBL in childhood is probably more common than previously reported. Any association between AMBL and a particular cytogenetic abnormality must await further cytogenetic studies, specifically those employing banding techniques.

Acid Phosphatase↗

Effects of cyclophosphamide, cis-platinum, nitrosourea (ACNU), melphalan, and dacarbazine on a cytogenetically highly malignant neuroblastoma xenograft.

The effects of eight different chemotherapeutic agents were studied on a human neuroblastoma xenograft, designated TNB9, according to the standard Battelle Columbus Laboratories protocol. Cytogenetically and molecular-cytogenetically, this xenograft is known to have a homogeneously staining region (HSR) on chromosome 20 and to exhibit 60- to 80-fold amplification of clone #8 (1.75 kb) and N-myc (2.1 kb) in the HSR. Our previous analyses of cytogenetic and phenotypic characteristics on nine human neuroblastoma xenografts demonstrated that TNB9 is one of the most malignant strains of neuroblastoma. The in vivo chemotherapeutic sensitivity assessment disclosed that cyclophosphamide, cis-platinum, nitrosourea (ACNU), melphalan, and dacarbazine (DTIC) are effective, while aclarubicin, vincristine, and cytosine arabinoside are quite ineffective against this neuroblastoma xenograft.

Adolescent↗

Cytogenetic abnormalities of small round cell tumours.

Between 1987 and 1991, cytogenetic studies were carried out on small round cell tumours of 68 patients from the Northern Health Region of England. Clonal chromosome abnormalities were found in 30, comprising 15 neuroblastomas, 7 Ewing's tumours, 7 rhabdomyosarcomas, and 1 granular cell tumour. Characteristic rearrangements were found in five cases of Ewing's tumour [all with translocation t(11;22) (q24;q12)] and in four cases of rhabdomyosarcoma [all with evidence of translocation t(2;13) (q35-37;q14)]. In one case of Ewing's tumour and three of rhabdomyosarcoma, the cytogenetic findings were important in diagnosis. Within the neuroblastomas, examples were found of hyperdiploidy, 1p rearrangements, double minute chromosomes, and homogeneously staining regions, but too few cases were available for prognostic associations to be assessed. Our findings confirm the diagnostic importance of chromosome abnormalities in small round cell tumours and indicate that cytogenetic analysis should be an intrinsic part of the initial investigations of all patients with such tumours.

Adolescent↗

Cytogenetic and molecular studies of t(14;18) and t(14;19) in nodal and extranodal B-cell lymphoma.

We have examined 107 cases of B-cell lymphoma for the t(14;18) translocation, characteristically described in follicular lymphoma. B-Cell lymphomas of extranodal origin, and in particular malignancies derived from mucosa-associated lymphoid tissue (MALT), were compared with node-based lymphomas of follicular and diffuse morphology. Cytogenetic techniques were supplemented by molecular analysis using probes which recognize both the major and the minor breakpoint regions of the bcl-2 gene located on chromosome 18 (q21). t(14;18) was detected in 55 per cent of follicular and 27 per cent of diffuse B-cell lymphomas thought to be of follicle centre cell origin. Cytogenetics and molecular analysis proved equally effective in demonstrating the translocation. t(14;18) was not observed in the 36 extranodal lymphomas examined, of which 20 were characterized histologically as lymphomas of MALT, using either technique. In addition, 30 cases demonstrated only a germline band when probed with a bcl-3 probe specific for t(14;19), a translocation observed in chronic lymphocytic leukaemia (CLL). Cytogenetic abnormalities were detected in all cases of extranodal lymphoma, although no consistent abnormality was observed. Numerical abnormalities of chromosomes 3, 6, 16, and 18; structural abnormalities of chromosomes 2, 6, 8, and 9; and small marker chromosomes were frequently seen. This study provides data which suggest that different genetic events are involved in the development of lymphoma of MALT from those giving rise to follicle centre cell lymphomas.

Autoradiography↗

DNA cytometric and interphase cytogenetic analyses of paraffin-embedded hydatidiform moles and hydropic abortions.

The combined application of DNA cytometric and interphase cytogenetic analyses was used to find objective criteria for the differential diagnosis of complete hydatidiform mole, partial hydatidiform mole and hydropic abortion. DNA ploidy and G0/G1 exceeding rates were determined using image and flow cytometric analyses on paraffin-embedded tissues of 166 cases: 71 cases of complete mole, 20 cases of partial mole, and 75 cases of abortions. To determine the existence and histological distribution of cell subpopulations with numerical chromosome aberrations, interphase cytogenetic analysis using probes specific for chromosomes 1, X, and Y was applied to paraffin tissue sections of 23 cases: 12 cases of complete mole, 3 cases of partial mole, and 8 cases of abortions. In contrast to previously reported findings that complete moles are diploid, the results of this study showed that complete moles are DNA-polyploid (96 per cent), with high G0/G1 exceeding rates and a high frequency of numerical chromosomal aberrations in the trophoblast hyperplasia. The majority of the partial moles were DNA-triploid (55 per cent). This study, however, also showed the presence of DNA-polyploid partial moles (30 per cent). Abortions were DNA-diploid (60 per cent) or DNA-triploid (39 per cent). DNA cytometric analysis, especially image DNA cytometric analysis with determination of the G0/G1 exceeding rate, and interphase cytogenetic analysis provide objective measurements which are contributory in the differential diagnosis between complete mole, partial mole, and hydropic abortion.

DNA↗