The effect of structural aberrations of the chromosomes on reproductive fitness in man

Reproductive fitness was measured in the following seven classes of pedigrees: (1) D/D Robertsonian translocations ascertained through a euploid proband; (2) D/G Robertsonian translocations ascertained through a euploid proband: (3) reciprocal translocations ascertained through a euploid proband; (4) inversions ascertained through a euploid proband; (5) all translocations and inversions ascertained through an aneuploid proband; (6) those ascertained through a proband with a ring, marker, or supernumerary chromosome; (7) those ascertained through a proband with an extreme variant chromosome. For each group reproductive fitness was calculated in two ways. One method was based on live births, fetal and infant deaths and generation time of those individuals carrying a chromosome abnormality or variant by comparison with their first degree relatives who were known to have a normal chromosome constitution. The second method was based on the proportion of sporadic cases obtained from segregation analysis. The results obtained using both methods are presented and discussed.     

The effect of structural aberrations of the chromosomes on reproductive fitness in man

Methods are presented to estimate relative fitness of carriers as a function of fertility, survival, are generation time in pedigrees under incomplete ascertainment. A large sample of diverse chromosomal aberrations reveals significant effects on all three parameters, giving a relative fitness of .769 +/- .039. There is no significant shift in segregation frequency. Implications of these results for population dynamics of structural rearrangements are discussed. The following paper applies these methods to specific classes of aberrations.     

Chromosome 1 aberrations in cancer

Evidence for chromosome #1 involvement in structural rearrangements in cancer is reviewed. There have been adequate studies of cancer at most of the common sites, and at all of these, nonrandom chromosome #1 involvement has been demonstrated. In general, a variety of changes is encountered, irrespective of the site; most commonly, however, the changes result in the duplication of long arm material. It seems that these nonrandom changes, which tend to occur at a relatively late stage, may contribute to the progression of all forms of cancer. However, a small number of chromosome #1 aberrations are also now known, which may represent specific and possibly initiating changes in particular forms of cancer. These include short arm deletions in neuroblastoma and translocations in leukemias and myelodysplasia.     

Detection of numerical chromosome aberrations in bladder cancer by in situ hybridization.

The nuclear DNA content of 53 transitional cell carcinomas (TCCs) of the urinary bladder, as determined by flow cytometry (FCM), was compared with chromosome ploidy as detected by nonradioactive in situ hybridization (ISH). For this purpose, probes for repetitive DNA targets in the (peri) centromeric region of chromosomes 1 and 18 were used. Hybridization results with both probes of 35 TCCs, which had a DNA index of approximately 1.0 as concluded from FCM, showed evident chromosome 1 aberrations in approximately 25% of the tumors, and in a few cases an aberration for chromosome 18 was detected. Comparison of the ISH spot numbers for both chromosomes showed in most cases a higher number for chromosome 1 than for chromosome 18. ISH on 18 cases of TCCs, which showed a single peak in FCM with a DNA-index of 1.2 to 3.2, exhibited a profound heterogeneity. In these TCCs the ratio between chromosomes 1 and 18 varied over a wide range, resulting in cases showing more hybridization signals for chromosome 1 than for chromosome 18 or the opposite. Furthermore, using ISH minor cell populations showing polyploidization and giant cells containing numerous ISH signals could occasionally be detected. Results showed that interphase cytogenetics by ISH enable a fast screening of numerical chromosome aberrations and detection of different cell populations within one tumor, which was apparently homogeneous according to FCM.     

Nonrandom structural and numerical chromosome changes in non-small-cell lung cancer

Cytogenetic studies were performed on 27 tumor cell lines (most of which were derived from metastatic lesions) and four fresh malignant pleural and pericardia! effusions from 30 patients with non-small-cell lung cancer (non-SCLC). Many clonal structural (deletions and nonreciprocal translations) and numerical abnormalities were found in each specimen. Statistical analysis revealed these changes were nonrandomly distributed among the chromosomes. A statistically significant number of chromosomal breakpoints were seen in regions 1 q 1, 1 q3, 3p1, 3p2, 3q1, 3q2, 7q1, 13p1, 14p1, 15p1, and 17q1 when the regions were compared to the total haploid complement. In addition, when a given region was compared to other regions within the same chromosome, statistically significant numbers of breakpoints were noted for regions 1q3, 5q1, 7q1, 13p1, 14p1, 15p1, 16q2, 17q1, and 21p1. Specific chromosome bands showing the most frequent involvement in structural abnormalities were (in descending order) 3p 14.2, 3q21, 19q13, 11p15, 1q11, 7q111, 1q21, 3p23, and 3p21. The breakpoints indicate areas to look for new dominant oncogenes activated by translocations, while the areas of deletions and loss of material by nonreciprocal translocations highlight areas to search for recessive oncogenes. These cytogenetic studies represent strong evidence that multiple genetic lesions are associated with the development of metastatic lung cancer, and provide a roadmap to search for new genes involved in the pathogenesis of lung cancer.     

Detection of numerical and structural alterations and fusion of chromosomes 16 and 1 in low-grade papillary breast carcinoma by fluorescence in situ hybridization.

Intracystic papillary breast tumors, including intraductal papilloma and low-grade intracystic papillary carcinoma, constitute a group for which differential diagnosis is frequently difficult. We examined the status of chromosomes 16 and 1 by multicolor fluorescence in situ hybridization (FISH) analyses and the DNA ploidy patterns by flow cytometry in 26 intracystic papillary tumors. Alterations of chromosomes 16 and 1 were detected by FISH in 93 and 85%, respectively, of 14 low-grade papillary carcinomas, and the latter alterations always concurred with the former. Two-color FISH using probes for the D1Z1 (1q12) and D16Z2 (16cen) loci or the D1Z1 and D16Z3 (16q11) loci showed that fusion of chromosomes 16 and 1, mostly with breakpoints distal to 16q11.2 and proximal to 1q12, occurred in 77% of the papillary carcinomas. DNA aneuploidy was detected in 6% of these carcinomas. No papilloma showed these chromosome alterations or DNA aneuploidy. Chromosome 16 and 1 fusions appeared to occur frequently in diploid breast carcinomas and to be involved in the acquisition of a malignant phenotype by duct epithelial cells. We suggest that two-color FISH methods for detecting 1;16 fusions might be applicable as supportive methods for the differential diagnosis of intracystic papillary breast tumors.     

Numerical aberrations of chromosomes 1, 2, and 7 in astrocytomas studied by interphase cytogenetics

For both juvenile astrocytomas and astrocytomas of adults, numerical and structural aberrations of chromosomes 1 and 7 have been described. To study the frequency of those aberrations in more detail and to exclude in vitro artifacts, we investigated directly prepared material from 18 juvenile and 26 astrocytomas of adults by fluorescence in situ hybridization with DNA probes specific for chromosome regions 1p36, 1q12, 2cen, and 7cen. Chromosome 2 was used as control in the hybridization with chromosome 7. To exclude tissue-specific alterations, we tested cerebral and cerebellar paraffin-embedded material from persons who had died from other diseases. In 13 of the juvenile astrocytomas, we found a loss of 1p36 in relation to 1q12. In 16 astrocytomas of adults, a gain of signals from 1p36 or both probes for chromosome 1 was seen. Gain of chromosome 7 was found in 25 cases. Unexpectedly, gain of chromosome 2 occurred in 32 cases. For both probes, there was no difference between astrocytomas of children and those of adults. Our data suggest that loss of 1p is an early event in the development of juvenile astrocytomas and that trisomy 7 is frequent in malignant tumors and tumors containing a potential of growing malignantly. Genes Chromosom. Cancer 19:6–13, 1997. © 1997 Wiley-Liss, Inc.     

Numerical aberrations of chromosomes 1 and 7 in renal cell carcinomas as detected by interphase cytogenetics

Alcohol-fixed single cell suspensions of 37 renal cell carcinomas (RCCs) were assessed by both flow cytometry (FCM) and the fluorescence in situ hybridization (FISH) technique, using chromosome 1- and chromosome 7-specific centromere DNA probes. DNA diploidy or near-diploidy was observed in 30 of the 37 RCCs and only 12 of these (near-)diploid tumours were disomic for both chromosomes 1 and 7. Numerical aberrations of chromosome 1 and/or chromosome 7 were present in 18 of the 30 (near-)diploid RCCs and five of these cases showed monosomy for chromosome 1 in more than 50 per cent of the tumour cells. A double target FISH, with a centromeric and a telomeric specific probe for 1p36, excluded misinterpretation on the basis of clustering of 1q12, and suggested a complete loss of chromosome 1. All these five (near-)diploid RCCs with monosomy for chromosome 1 were eosinophilic chromophilic cell carcinomas, according to the Thoenes classification of RCC. This observation is of special interest, because it was recently concluded from cytogenetic studies that the diagnosis of chromophilic renal cell carcinoma must be considered as obsolete. Monosomy for chromosome 1 seems to be a non-random numerical aberration of (near-)diploid eosinophilic chromophilic cell carcinomas, and a gain of one or more chromosomes 1 appeared to be a common phenomenon in RCCs, especially in the DNA aneuploid tumours. As these chromosomal abnormalities were not found in the earlier classical cytogenetic studies, we conclude that in situ hybridization techniques are required in addition to chromosome banding techniques to obtain a complete characterization of the chromosome imbalances in RCCs.     

DNA in situ hybridization (interphase cytogenetics) versus comparative genomic hybridization (CGH) in human cancer: detection of numerical and structural chromosome aberrations

DNA in situ hybridization techniques for cytogenetic analyses of human solid cancers are nowadays widely used for diagnostic and research purposes. The advantage of this methodology is that it can be applied to cells in the interphase state, thereby circumventing the need for high-quality metaphase preparations for karyotypic evaluation. In situ hybridization (ISH) with chromosome specific (peri)centromeric DNA probes, also termed "interphase cytogenetics", can be used to detect numerical changes, whereas comparative genomic hybridization (CGH) discloses chromosomal gains and losses, i.e. amplifications and deletions. We wanted to compare both methods in human solid tumors, and for this goal we evaluated ISH and CGH within a set of 20 selected prostatic adenocarcinomas. Chromosomes 7 and 8 were chosen for this analysis, since these chromosomes are frequently altered in prostate cancer. ISH with chromosome 7 and 8 specific centromeric DNA probes was applied to standard, formalin-fixed and paraffin-embedded, histological sections for numerical chromosome analysis. CGH with DNA's, extracted from the same histologic area of the archival specimens, was used for screening of gains and losses of 7 and 8. ISH with centromeric probes distinguished a total of 26 numerical aberrations of chromosome 7 and/or 8 in the set of 20 neoplasms. In the same set CGH revealed a total of 35 losses and gains. CGH alterations of 7 and 8 were seen in twenty-two of the 26 chromosomes (85%) that showed aberrations in the ISH analysis. Concordance between ISH and CGH was seen in 11 (of 26; 42%) chromosomes. Eight chromosomes were involved in gains (5 x #7, 3 x #8), three in losses (3 x #8). This included both complete (3/11) and partial (8/11) CGH confirmation of the numerical alteration. Partial CGH confirmation was defined as loss or gain of a chromosome arm with involvement of the centromeric region. In the majority of these cases it concerned a whole chromosome arm, mostly the long arm. We conclude that generally a fair correlation was found between ISH and CGH in interphase preparations of a series of prostate cancers. However, when specified in detail, most of the numerical ISH aberrations were only partly represented in the CGH analysis. On the one hand, it suggests that CGH does not adequately discriminate numerical abnormalities. On the other hand, it likely implies that not all numerical changes, as detected by interphase cytogenetics, are truly involving the whole chromosome. A part of these discrepancies might be caused by structural mechanisms, most notably isochromosome formation.     

Prognostic impact of deletions at 1p36 and numerical aberrations in Ewing tumors.

Ewing's sarcoma, peripheral primitive neuroectodermal tumors, and Askin tumors are referred to as Ewing tumors (ETs), and are characterized by high MIC2 expression and a t(11;22)(q24;q12) or other rearrangements involving 22q12. In addition to these constant aberrations, facultative numerical and structural aberrations have been reported: gains of chromosomes 8 and 12, the unbalanced translocation t(1;16), and deletions at the short arm of chromosome 1. To evaluate the frequency and to study the biological impact of these facultative aberrations, we analyzed tumor specimens from 58 ET patients by classical cytogenetics and/or in situ hybridization techniques and compared these data with clinical parameters. Gains of chromosomes 8 and 12 were detected in 55% (32/58) and 24% (14/58) of the cases, respectively. Loss of chromosome 16 or der (16)t(1;16) chromosomes were found in 20% (10/51); deletions at 1p36 were observed in 18% (9/51) of the cases evaluated. The presence of these aberrations did not correlate with age and sex of the patients, with the location of the primary tumor or with the extent of disease at diagnosis by chi-square analysis and Fisher's exact test. Patients with tumors harboring gains of chromosome 8 showed a slightly better clinical outcome (n = 14/30, P = 0.17), whereas gains of chromosome 12 did not influence the clinical outcome (n = 7/30, P = 0.63). However, Kaplan and Meier analysis revealed that deletions at the short arm of chromosome 1 were associated with an unfavorable outcome in patients with localized disease (n = 6/22; P = 0.004).     

1p13 is the most frequently involved band in structural chromosomal rearrangements in human breast cancer

Cytogenetic data on 14 breast carcinomas were examined to determine which chromosome arms and bands are preferentially involved in structural chromosome changes. Chromosome arms 17p, 16q, and 1p and band 1p13 were found to be significantly involved. A review of the world literature confirmed 1p as being the most frequently involved arm in structural chromosome changes in breast cancer and 1p13 as being the band most frequently involved in such changes. The two sets of results were pooled, and the analysis of 113 tumours revealed 229 of 304 bands to be involved, with 1p13 affected in 20% of the tumours.     

Sex chromosomes in a series of 79 colorectal cancers: replication pattern, numerical, and structural changes

The cytogenetic study of a series of 79 colorectal cancers was performed with special attention to sex chromosome behavior. It was found that apart from other chromosomal changes, the early-replicating X chromosome (Xe) was frequently duplicated in tumors from both males and females. This contrasted with a frequent loss of either the late-replicating X (XI) in tumors from females or of the Y chromosome in tumors from males. All the detected unbalanced rearrangements resulted in a gain of the long, but not the short, arm of the X chromosome. The replication pattern of Xe chromosomes was similar to that of control tissues, whereas that of XI chromosomes was unusual. Its main characteristic was that the two major R bands of the short arm, Xp11 and Xp22, replicated too early.     

双色荧光原位杂交检测苯系物接触者精子7、8号染色体数目畸变

目的　检测苯系物接触者精子 7、8号染色体数目畸变率。方法　用生物素标记 7号染色体探针 (D7Z1)和地高辛标记 8号染色体探针 (D8Z1)与精子核进行双色荧光原位杂交 ,测定精子染色体畸变率。结果　车间空气中苯的时间加权浓度为 42 .2 9mg/m3 ,高于国家卫生标准 ( 6mg/m3 )。苯系物接触者尿粘康酸浓度 ( 0 .861mg/g肌酐 ) ,高于对照组 ( 0 .44 4mg/g肌酐 )。杂交效率 99.77%～ 99.97% ,共计数15例苯系物接触者 15 5 72 1条精子核和 12名对照组者 12 3 771条精子核型。接触组二倍体精子率 ,平均7、8号染色体双体精子率 (分别为 0 .12 9%、0 .170 %和 0 .0 78% )均高于对照组 (分别为 0 .0 5 5 %、0 .0 5 3 %、0 0 3 3 % )。接触组 7号、8号染色体缺体精子率 (分别为 0 .165 %和 0 .0 88% ) ,也分别高于对照组 ( 0 .0 5 6%、0 0 2 9% )。总数目畸变精子率接触组为 0 .745 % ,高于对照组的 0 .2 89%。结论　较高浓度的苯系物暴露可引起接触者精子 7、8号染色体非整倍体率和二倍体精子率增高。     

Glutathione S-transferase genotypes and numerical chromosomal aberrations in myeloid neoplasms

The aim of the present study was to detect the frequency of monosomy 7 and trisomy 8 in myeloid disorders (acute myeloblastic leukemia (AML), myelodysplastic syndrome (MDS)), their association with GSTT1 and GSTM1 null genotypes, and their prognostic impact. The study included 50 patients with AML and MDS; monosomy 7 and trisomy 8 detection was done by interphase fluorescence in situ hybridization, and glutathione S-transferase (GST) genotyping was done by multiplex PCR. Monosomy 7 was present in 13–30 % of AML and MDS, respectively. A statistically significant relation was found between monosomy 7 and remission failure. Trisomy 8 was found in 10–15 % of AML and MDS. No significant association was found between response to treatment and trisomy 8. There was significant correlation between GSTT1 null/GSTM1 null genotype and poor response to treatment (p < 0.005). There was positive correlation between complete remission and both wild GST genotypes. In the whole patient group, a statistically significant association was found between GSTT null genotypes and monosomy 7 (p = 0.003). No significant association was found between trisomy 8 and specific GST genotypic polymorphism.     

Nuclear envelope structural defects cause chromosomal numerical instability and aneuploidy in ovarian cancer

Background  

Despite our substantial understanding of molecular mechanisms and gene mutations involved in cancer, the technical approaches for diagnosis and prognosis of cancer are limited. In routine clinical diagnosis of cancer, the procedure is very basic: nuclear morphology is used as a common assessment of the degree of malignancy, and hence acts as a prognostic and predictive indicator of the disease. Furthermore, though the atypical nuclear morphology of cancer cells is believed to be a consequence of oncogenic signaling, the molecular basis remains unclear. Another common characteristic of human cancer is aneuploidy, but the causes and its role in carcinogenesis are not well established.