Characteristic pattern of chromosomal gains and losses in primary large B-cell lymphomas of the gastrointestinal tract

In contrast to low-grade B-cell lymphomas originating in the gastrointestinal (GI) tract, only few cytogenetic data are available for the large cell, highly malignant variants. We studied 31 large B-cell lymphomas of the GI tract by comparative genomic hybridization (CGH) and fluorescence in situ hybridization using specific DNA probes (FISH). The most frequent aberrations were gains of all or of parts of chromosomes 11 (11 cases), 12 (9 cases), 1q (4 cases), and 3q (4 cases). Losses of parts of chromosome 6q and of parts of the short arm of chromosome 17 (6 cases each) were found most frequently. In four cases a total of seven high-level DNA amplifications was detected. In two of these cases, involvement of specific protooncogenes (REL and MYC) was shown. Some genetic aberrations seemed to be associated with an inferior clinical course: patients with >/=2 aberrations had a significantly shorter median survival. Furthermore, all patients with gains of all or parts of chromosome arm 1q and with high-level DNA amplifications as well as seven of nine patients with gains of all or parts of chromosome 12 died of lymphoma. In conclusion, the pattern of chromosomal gains and losses in large B-cell lymphomas was different from data reported for low-grade (MALT) lymphomas of the stomach and bowel, especially with respect to the high incidence of partial gains of chromosome arm 11q and of all or parts of chromosome 12 and the low frequency of polysomy 3. In addition, our data suggest that chromosomal gains and losses detected by CGH and FISH may predict for the outcome of patients with this tumor entity.     

Cytogenetic analysis of pancreatic carcinomas: intratumor heterogeneity and nonrandom pattern of chromosome aberrations

Twenty-nine nonendocrine pancreatic carcinomas (20 primary tumors and nine metastases) were studied by chromosome banding after short-term culture. Acquired clonal aberrations were found in 25 tumors and a detailed analysis of these revealed extensive cytogenetic intratumor heterogeneity. Apart from six carcinomas with one clone only, 19 tumors displayed from two to 58 clones, bringing the total number of clones to 230. Karyotypically related clones, signifying evolutionary variation, were found in 16 tumors, whereas unrelated clones were present in nine, the latter finding probably reflecting a distinct pathogenetic mechanism. The cytogenetic profile of pancreatic carcinoma was characterized by multiple numerical and structural changes. In total, more than 500 abnormal chromosomes, including rings, markers, homogeneously stained regions, and double minutes, altogether displaying 608 breakpoints, were detected. This complexity and heterogeneity notwithstanding, a nonrandom karyotypic pattern can be discerned in pancreatic cancer. Chromosomes 1, 3, 6, 7, 8, 11, 12, 17, and 19 and bands 1q12, 1q21, 3q11, 6p21, 6q21, 7q11, 7q22, 7q32, 11q13, 13cen, 14cen, 17q11, 17q21, and 19q13 were most frequently involved in structural rearrangements. A total of 19 recurrent unbalanced structural changes were identified, 11 of which were not reported previously: del(1)(q11), del(3)(p11), i(3)(q10), del(4)(q25), del(11)(p13), dup(11)(q13q23), i(12)(p10), der(13;15)(q10;q10), del(18)(q12), del(18)(q21), and i(19)(q10). The main karyotypic imbalances were entire-copy losses of chromosomes 18, Y, and 21, gains of chromosomes 7, 2, and 20, partial or whole-arm losses of 1p, 3p, 6q, 8p, 9p, 15q, 17p, 18q, 19p, and 20p, and partial or whole-arm gains of 1q, 3q, 5p, 6p, 7q, 8q, 11q, 12p, 17q, 19q, and 20q. In general, the karyotypic pattern of pancreatic carcinoma fits the multistep carcinogenesis concept. The observed cytogenetic heterogeneity appears to reflect a multitude of interchangeable but oncogenetically equivalent events, and the nonrandomness of the chromosomal alterations underscores the preferential pathways involved in tumor initiation and progression.     

The t(11;18)(q21;q21) chromosome translocation is a frequent and specific aberration in low-grade but not high-grade malignant non-Hodgkin's lymphomas of the mucosa-associated lymphoid tissue (MALT-) type

Primary extranodal malignant non-Hodgkin's lymphoma arising from the mucosa-associated lymphoid tissue (MALT-type lymphoma) represents a subtype of B-cell lymphoid malignancies with distinct clinicopathological features and is often associated with a favorable prognosis. Unlike the situation in nodal non-Hodgkin's lymphoma of B-cell lineage, few data are still available concerning the chromosomal constitution of MALT-type lymphomas. Until now, cytogenetic data from 29 low-grade MALT lymphomas with karyotypic alterations have been reported from different institutions, and virtually no data were available for high-grade MALT-type lymphomas. We have analyzed the cytogenetics of 44 MALT lymphomas arising in the stomach, parotid gland, thyroid gland, lung, breast, and conjunctiva. Clonal chromosome aberrations have been detected in 13 of 20 (65%) low-grade and 20 of 24 (83%) high-grade tumors. More than half of the low-grade lymphomas with abnormal karyotypes (7 of 13 cases, 53%) displayed clonal t(11;18)(q21;q21), thus specifically associating this translocation with MALT-type lymphomas for the first time in a larger series. In contrast, t(11;18) was not found in a single case of 20 high-grade MALT-type lymphomas with abnormal karyotypes, nor were translocations t(14;18) or t(3;14), characterizing about 10-35% of primary nodal large cell lymphomas. Instead, these lymphomas were associated with t(8;14)(q24;q32) in three cases, frequent deletions in the long arm of chromosome 6, and partial or whole gains of chromosomes 3, 7, 17, 18, and 21.     

Clinical and pathological significance of numerical aberrations of chromosomes 11 and 17 in colorectal neoplasms

Numerical chromosome aberrations by interphase cytogenetic analysis have been reported in a few samples of colorectal neoplasms. No studies have defined a distinct relationship between these aberrations and clinicopathological features. To investigate the chromosome aberrations as a marker of invasiveness or prognosis, we conducted an interphase cytogenetic study using fluorescence in situ hybridization and examined 142 colorectal neoplasms consisting of 15 adenomas and 127 cancers. The target chromosomes were chromosomes 11 and 17. We also evaluated the nuclear DNA content as detected by flow cytometry, analyzed the relationship between the frequency of aneusomy and clinicopathological features, and examined the survival rate in these patients. The loss of chromosome 11 was observed in 31% of adenomas, whereas in cancers DNA aneuploidy was observed in 63% of cases, a gain of chromosome 17 was observed in 63% of cases, and a gain of chromosome 11 was observed in 42% of cases. Numerical chromosome aberrations in diploid DNA were also observed. Increased depth of invasion (>/=T3) and advanced Dukes' stage (>/=B) of malignant tumors were associated with a higher frequency of a gain of chromosome 11 (P < 0.01 and P < 0.05, respectively). Increased depth of invasion (>/=T2) in cancers was associated with a higher frequency of a gain of chromosome 17 (P < 0.05). Multivariate analysis of postoperative survival showed that a loss or gain of chromosome 11 was independently associated with a poor prognosis (P < 0.05). Numerical chromosome aberrations appear prior to the alteration of nuclear DNA content as detected by flow cytometry and influence the progression of colorectal cancers. Aneusomy of chromosome 11 is associated with poor postoperative prognosis of primary colorectal cancers.     

Detection of chromosomal aberrations in seminomatous germ cell tumours using comparative genomic hybridization

Comparative genomic hybridization (CGH) was used to evaluate tissue specimens from 16 seminomas in order to elucidate the pathogenesis of germ cell tumours in males. A characteristic pattern of losses and gains within the entire genomes was detected in 94% of the seminomas by comparing the ratio profiles of the tumours with a standard of cytogenetically normal genomic DNA. Losses represented 43% of the total number of alterations often affecting chromosomes and chromosome arms 4, 5, 11, 13q, and 18q. Gains amounted to 57% and were often observed on 1q, 7, 8, 12, 14q, 15q, 21q, and 22q. Aberrations of 12p and 21q appeared most consistently. Results from CGH analysis displayed no relationship to the clinical stages of the malignancy. Some rare aberrations appeared, however, only in clinical stage II and in tumours showing relapse in the contralateral testis following orchiectomy, although the alterations were not present in all of the tumours in question. Losses of 16q13-21 and gains of 9q22.1-22.2 were demonstrated in both groups, while loss of 16p12 and gains of 6p21 and 6q23.3-24 were detected in the latter group as well. In conclusion, a specific pattern of chromosomal alterations was demonstrated in the seminomas by improved detection criteria, which increased specificity and sensitivity. The rare aberrations, which appeared only in tumours in improved detection criteria, which increased specificity and sensitivity. The rare aberrations, which appeared only in tumours in clinical stage II and relapsed tumours, may be linked to tumour progression, invasiveness, and bilateral disease.     

Chromosomal abnormalities in glioblastoma multiforme tumors and glioma cell lines detected by comparative genomic hybridization

Comparative genomic hybridization (CGH) is a recent molecular cytogenetic method that detects and localizes gains or losses in DNA copy number across the entire tumor genome. We used CGH to examine 9 glioma cell lines and 20 primary and 10 recurrent glioblastoma tumors. More than 25% of the primary tumors had gains on chromosome 7; they also had frequent losses on 9p, 10, 13 and Y. The losses on chromosome 13 included several interstitial deletions, with a common area of loss of 13q21. The recurrent tumors not only had gains on chromosome 7 and losses on 9p, 10, 13 and Y but also frequent losses on 6 and 14. One recurrent tumor had a deletion of 10q22-26. Cell lines showed gains of 5p, 7 and Xp; frequent amplifications at 8q22-24.2, 7q21-32 and 3q26.2-29 and frequent losses on 4, 10, 13, 14 and Y. Because primary and recurrent tumors and cell lines showed abnormalities of DNA copy number on chromosomes 7, 10, 13 and Y, these regions may play a fundamental role in tumor initiation and/or progression. The propensity for losses on chromosomes 6 and 14 to occur in recurrent tumors suggests that these aberrations play a role in tumor recurrence, the development of resistance to therapy or both. Analysis of common areas of loss and gain in these tumors and cell lines provides a basis for future attempts to more finely map these genetic changes.     

Somatic deletion mapping on chromosome 10 and sequence analysis of PTEN/MMAC1 point to the 10q25-26 region as the primary target in low-grade and high-grade gliomas

The 10q25-26 region between the dinucleotide markers D10S587 and D10S216 is deleted in glioblastomas and, as we have recently shown, in low-grade oligodendrogliomas. We further refined somatic mapping on 10q23-tel and simultaneously assessed the role of the candidate tumor suppressor gene PTEN/MMAC1 in glial neoplasms by sequence analysis of eight low-grade and 24 high-grade gliomas. These tumors were selected for partial or complete loss of chromosome 10 based on deletion mapping with increased microsatellite marker density at 10q23-tel. Three out of eight (38%) low-grade and 3/24 (13%) high-grade gliomas exclusively target 10q25-26. We did not find a tumor only targeting 10q23.3, and most tumors (23/32, 72%) showed large deletions on 10q including both regions. The sequence analysis of PTEN/MMAC1 revealed nucleotide alterations in 1/8 (12.5%) low-grade gliomas in a tumor with LOH at l0q21-qtel and in 5/21 (24%) high-grade gliomas displaying LOH that always included 10q23-26. Our refined mapping data point to the 10q25-26 region as the primary target on 10q, an area that also harbors the DMBT1 candidate tumor suppressor gene. The fact that we find hemizygous deletions at 10q25-qtel in low-grade astrocytomas and oligodendrogliomas - two histologically distinct entities of gliomas - suggests the existence of a putative suppressor gene involved early in glial tumorigenesis.     

Cytogenetic studies of epithelial ovarian carcinoma

We performed cytogenetic studies of 36 human epithelial ovarian carcinomas using in situ culture and robotic harvest. We obtained analyzable metaphases of all 36 tumors (100%). One or more chromosomally abnormal clones were observed in 80% of tumors. Common clonal chromosome gains (each occurring in six or more cases) included +1, +2, +3, +6, +7, +9, and +12. Common clonal chromosome losses (occurring in 12 or more cases) included -X, -4, -8, -11, -13, -15, -17, and -22. Common clonal structural abnormalities (occurring in four or more cases) involved regions 1p36, 1q32, 1q42, 3p13-->p26, 3q26-->q29, 7p22, 9q34, 11p13-p15, 17q21-->q23, 19p13.3, and 19q13.3. Trisomy 12 was noted as the sole anomaly in three of five borderline and grade 1 tumors. Two grade 2 tumors contained i(1q), -14, -15 and -22. The results suggest that the pathogenesis of borderline and low-grade tumors may differ from that of higher grade tumors. Two high-grade tumors had an apparent translocation between 17q21 and 19p13.3, two chromosome regions believed to be critical to ovarian carcinogenesis.     

Accumulation of genetic changes is associated with poor prognosis in grade II astrocytomas

Unexpectedly aggressive clinical course of some grade II astrocytomas is a diagnostic dilemma for routine histopathology. Because increasing tumor malignancy is a consequence of progressive accumulation of chromosomal alterations, we investigated whether aggressive behavior of grade II astrocytomas could be predicted by the number and type of gross chromosomal aberrations. We used comparative genomic hybridization to analyze 11 grade II astrocytomas with typical (good, n = 7) or poor (n = 4) prognosis. The results were also compared with a reference material of 13 grade III-IV astrocytomas and nine established cell lines. We found a median of two aberrations (range 0 to 4) in tumors with good prognosis and of 15.5 changes (range 8 to 28) in tumors with poor prognosis. Chromosomal gains were present in both groups, whereas chromosomal losses were frequent in tumors with poor prognosis (median 9.5, range 3 to 14) but rare in tumors with good prognosis (range 0 to 2). All chromosomal gains were also found in the high-grade astrocytoma group and the majority of them in cell lines. Chromosomal losses in grade II astrocytomas with poor prognosis were very similar to those in grade III-IV astrocytomas and cell lines. We conclude that an early accumulation of genetic changes in grade II astrocytomas is closely associated with poor patient prognosis, suggesting diagnostic use for comparative genomic hybridization in characterization of grade II astrocytomas.     

Distinct patterns of chromosomal alterations in high- and low-grade head and neck squamous cell carcinomas

Comparative genomic hybridization was performed on 30 primary head and neck squamous cell carcinomas. Fractional or entire DNA loss of chromosome 3p was a basic finding that occurred in 29 cases (97%). Additional DNA underrepresentations were observed in more than 50% of the cases on chromosomes 1p, 4, 5q, 6q, 8p, 9p, 11q, 13q, 18q, and 21q. Deletions on chromosomes 3p, 13q, and 17p were confirmed by loss of heterozygosity analysis. Entire or partial DNA copy number increases were identified for chromosome 3q in 26 cases (87%) with high-level amplifications at 3q24 and 3q27-qter. Overrepresentations were found in decreasing order of frequency at 11q13 (70%), 8q (57%), 19q (50%), 19p (47%), and 17q (47%). The use of comparative genomic hybridization superkaryograms of the group of well-differentiated carcinomas (G1) indicated that the deletions on chromosomes 3p and 9p along with the overrepresentation of 3q are associated with early tumor development. Accordingly, the undifferentiated tumors (G3) were characterized by additional deletions on chromosomes 4q, 8p, 11q, 13q, 18q, and 21q and overrepresentations on 1pter, 11q13, 19, and 22q, suggesting that these changes are preferentially associated with tumor progression.     

Tumor cytogenetics revisited: comparative genomic hybridization and spectral karyotyping

Fluorescence in situ hybridization techniques allow the visualization and localization of DNA target sequences on the chromosomal and cellular level and have evolved as exceedingly valuable tools in basic chromosome research and cytogenetic diagnostics. Recent advances in molecular cytogenetic approaches, namely comparative genomic hybridization and spectral karyotyping, now allow tumor genomes to be surveyed for chromosomal aberrations in a single experiment and permit identification of tumor-specific chromosomal aberrations with unprecedented accuracy. Comparative genomic hybridization utilizes the hybridization of differentially labeled tumor and reference DNA to generate a map of DNA copy number changes in tumor genomes. Comparative genomic hybridization is an ideal tool for analyzing chromosomal imbalances in archived tumor material and for examining possible correlations between these findings and tumor phenotypes. Spectral karyotyping is based on the simultaneous hybridization of differentially labeled chromosome painting probes (24 in human), followed by spectral imaging that allows the unique display of all human (and other species) chromosomes in different colors. Spectral karyotyping greatly facilitates the characterization of numerical and structural chromosomal aberrations, therefore improving karyotype analysis considerably. We review these new molecular cytogenetic concepts, describe applications of comparative genomic hybridization and spectral karyotyping for the visualization of chromosomal aberrations as they relate to human malignancies and animal models thereof, and provide evidence that fluorescence in situ hybridization has developed as a robust and reliable technique which justifies its translation to cytogenetic diagnostics.     

Cytogenetic analysis of 109 pediatric central nervous system tumors

Reports of cytogenetic abnormalities in pediatric central nervous system (CNS) tumors are important for collection and comparison of large numbers of karyotypes of primary CNS neoplasms to produce statistically significant correlations. We report cytogenetic results of 119 samples of pediatric CNS tumors from 109 patients. Tumors included 33 low-grade astrocytomas, 18 high-grade astrocytomas, 14 gangliogliomas, 13 ependymomas, 17 primitive neuroectodermal tumors (PNET), three choroid plexus papillomas and carcinomas, and a miscellaneous group of 20 rare primary CNS tumors and metastases. In each group, cytogenetic results were correlated with histologic subtype and survival. The study indicated specific chromosome abnormalities in different groups of tumors. Low-grade astrocytomas showed mostly numeric abnormalities with gains of chromosome 7, high-grade astrocytomas showed differences from karyotypic changes observed in adults in lacking double minutes (dmin) and monosomy 10. The ependymoma group showed the largest proportion of abnormal karyotypes with frequent involvement of chromosome 6 and 16. Chromosome 6 was the single most common abnormal chromosome in this study, closely followed by chromosomes 1 and 11. Pediatric CNS neoplasms differ from adult tumors cytogenetically as well as histologically and biologically.     

Detection of homonuclear decoupled in vivo proton NMR spectra using constant time chemical shift encoding: CT-PRESS

We revisited the cytogenetic alterations of the cervical adenocarcinoma cell line HeLa through the use of spectral karyotyping (SKY), comparative genomic hybridization (CGH), and fluorescence in situ hybridization (FISH). SKY analysis unequivocally characterized all abnormal chromosomes. Chromosomal breakpoints were primarily assigned by simultaneous assessment of SKY painted chromosomes and inverted 4,6-diamidino2-phenylindole banding from the same cell. Twenty clonally abnormal chromosomes were found. Comparison with previously reported HeLa G-banding karyotypes revealed a remarkably stable cytogenetic constitution because 18 of 20 markers that were found were present before. The classification of 12 markers was refined in this study. Our assignment of the remaining six markers was consistent with those described in the literature. The CGH map of chromosomal copy number gains and losses strikingly matched the SKY results and was, in a few instances, decisive for assigning breakpoints. The combined use of molecular cytogenetic methods SKY, CGH, and FISH with site-specific probes, in addition to inverted 4,6-diamidino-2-phenylindole or conventional G-banding analysis, provides the means to fully assess the genomic abnormalities in cancer cells. Human papillomaviruses (HPVs) are frequently integrated into the cellular DNA in cervical cancers. We mapped by FISH five HPV18 integration sites: three on normal chromosomes 8 at 8q24 and two on derivative chromosomes, der(5)t(5;22;8)(qll;q11q13;q24) and der(22)t(8; 22)(q24;q13), which have chromosome 8q24 material. An 8q24 copy number increase was detected by CGH. Dual-color FISH with a c-MYC probe mapping to 8q24 revealed colocalization with HPV18 at all integration sites, indicating that dispersion and amplification of the c-MYC gene sequences occurred after and was most likely triggered by the viral insertion at a single integration site. Numerical and structural chromosomal aberrations identified by SKY, genomic imbalances detected by CGH, as well as FISH localization of HPV18 integration at the c-MYC locus in HeLa cells are common and representative for advanced stage cervical cell carcinomas. The HeLa genome has been remarkably stable after years of continuous cultivation; therefore, the genetic alterations detected may have been present in the primary tumor and reflect events that are relevant to the development of cervical cancer.     

Multiple genetic aberrations including evidence of chromosome 11q13 rearrangement detected in pituitary adenomas by comparative genomic hybridization

OBJECT: This study was conducted to determine whether comparative genomic hybridization (CGH) is a more sensitive method for detecting genetic aberrations than other tests currently in use. METHODS: The authors used CGH to examine 40 primary and 13 recurrent adenomas obtained from 52 patients for loss and gain of genetic material. Copy number aberrations (CNAs) were detected in 25 (48%) of the 52 patients studied. The chromosomes affected were, in order of decreasing frequency, 11, 7, X, 1, 8, 13, 5, 14, 2, 6, 9, 10, 12, 3, 18, 21, 4, 16, 15, 19, 22, and Y. Endocrinologically active adenomas were more likely to contain (p = 0.009) and had a greater number (p = 0.003) of CNAs. Of 26 adenomas with CNAs, 18 showed multiple aberrations involving entire chromosomes or chromosome arms. The most frequent CNA involving a chromosome subregion, which was present in four (8%) of 53 adenomas, was the loss of all chromosome 11 material except for a preserved common segment containing 11q13. Immunoperoxidase staining did not detect cyclin D1 expression in those four cases, making cyclin D1 an unlikely target of this rearrangement. CONCLUSIONS: These findings indicate that genetic abnormalities are present in pituitary adenomas at a higher rate than previously reported, are associated with endocrinological activity, and often involve several chromosomes. Rearrangement at 11q13 may inactivate a tumor suppressor gene or activate an oncogene that is important in the initiation or progression of sporadic pituitary adenomas.     

Interphase cytogenetics of prostatic tumor progression: specific chromosomal abnormalities are involved in metastasis to the bone

Only limited data are available on chromosomes specifically involved in the multistep tumorigenesis of prostate cancer. To investigate the cytogenetic status at different stages of prostatic tumor development, we have applied interphase in situ hybridization (ISH) with a set of (peri) centromeric DNA probes--specific for chromosomes 1, 7, 8, and Y--to routinely processed tissue sections of prostatic specimens from 75 different individuals. Our panel consisted of: 16 normal/benign prostatic hyperplasia specimens; 23 primary, localized, prostatic tumors (N0M0 stage); 20 regional lymph node metastases (M0 stage); and 16 distant metastases. Numerical aberrations of at least one chromosome were not observed in normal/benign prostatic hyperplasia cases, but were present in localized tumors (39%), regional lymph node metastases (40%), and distant metastases (69%). Within the different pTNM groups, we observed the following aberrations (listed, within each series, in decreasing order of frequency): -Y, +8, -8, +7 in primary tumors; +8, +7, -Y, +Y, -8 in regional lymph node metastases; and +8, +7, +1, -Y, -8 in distant metastases. In primary tumors, the number of aberrant cases increased significantly with local tumor stage (p < 0.05). A significant increase in gain of chromosome 8 was also observed (p < 0.02). Gain of chromosome 7 and/or 8 showed a significant increase with progression of local tumor stage (p < 0.02). Specific involvement of chromosome 8 was seen in bone metastases, but not in hematogenous metastases to other sites (p = 0.02). Comparative genomic hybridization analysis of these bone metastases disclosed centromere 8 gains as amplifications of the (whole) 8q arm, whereas centromeric loss appeared to be due to loss of 8p sequences. With progression toward metastatic disease, an accumulation of genetic changes was seen as exemplified by gain of chromosome 1, which was solely observed in distant metastases. With tumor progression, gain of chromosomes 7 and/or 8 significantly increased (p = 0.03), whereas the number of cases with aberrations of the Y chromosome did not change. Furthermore, ploidy status determined by ISH revealed a significant increase in the number of aneuploid cases along with advancement of pTNM stage (p = 0.04). Collectively, the data strongly suggest that: (a) gain of chromosome 7 and/or 8 sequences is implicated in prostatic tumor progression; (b) gain of chromosome 8 sequences is related to local tumor growth; (c) overrepresentation of 8q sequences, most likely by isochromosome 8q formation, is involved in metastatic spread to the bone; and (d) changes in the centromeric copy number, as detected by interphase ISH, might in some cases represent structural alterations, such as an isochromosome.     

Chromosomal imbalances in primary and metastatic pancreatic carcinoma as detected by interphase cytogenetics: basic findings and clinical aspects

To date, cytogenetic studies on pancreatic carcinoma are rare, and little is known about the frequency of cytogenetic aberrations in primary carcinomas compared with metastatic tumour cells. We therefore evaluated the frequency of chromosomal aberrations in 12 primary pancreatic carcinomas and in effusion specimens from 25 patients with pancreatic cancer by using interphase fluorescence in situ hybridization (FISH) and a panel of four centromeric probes. Hyperdiploidy and chromosomal imbalances, predominantly affecting chromosome 8, were a constant finding in metastatic effusion cells, whereas concordant gain of chromosomes or relative loss of chromosome 18 characterized primary pancreatic carcinomas. The potential role of oncogenes located on chromosome 8 for pancreatic cancer progression was further investigated by double-hybridization studies of aneuploid effusion cells with a probe to 8q24 (MYC) and a centromeric probe to chromosome 8, which demonstrated amplification of the MYC oncogene in two of ten cases (20%). Finally, a potential application of basic findings in the clinical setting was tested by searching for micrometastatic cells in effusions from pancreatic cancer patients primarily negative by FISH. Two-colour FISH in combination with extensive screening (>10,000 nuclei) seems to be a useful tool to unequivocally identify micrometastatic cells by demonstrating hyperdiploidy and intranuclear chromosomal heterogeneity.     

Analysis of genomic alterations in benign, atypical, and anaplastic meningiomas: toward a genetic model of meningioma progression

Nineteen benign [World Health Organization (WHO) grade I; MI], 21 atypical (WHO grade II; MII), and 19 anaplastic (WHO grade III; MIII) sporadic meningiomas were screened for chromosomal imbalances by comparative genomic hybridization (CGH). These data were supplemented by molecular genetic analyses of selected chromosomal regions and genes. With increasing malignancy grade, a marked accumulation of genomic aberrations was observed; i.e., the numbers (mean +/- SEM) of total alterations detected per tumor were 2.9 +/- 0.7 for MI, 9.2 +/- 1.2 for MII, and 13.3 +/- 1.9 for MIII. The most frequent alteration detected in MI was loss on 22q (58%). In MII, aberrations most commonly identified were losses on 1p (76%), 22q (71%), 14q (43%), 18q (43%), 10 (38%), and 6q (33%), as well as gains on 20q (48%), 12q (43%), 15q (43%), 1q (33%), 9q (33%), and 17q (33%). In MIII, most of these alterations were found at similar frequencies. However, an increase in losses on 6q (53%), 10 (68%), and 14q (63%) was observed. In addition, 32% of MIII demonstrated loss on 9p. Homozygous deletions in the CDKN2A gene at 9p21 were found in 4 of 16 MIII (25%). Highly amplified DNA sequences were mapped to 12q13-q15 by CGH in 1 MII. Southern blot analysis of this tumor revealed amplification of CDK4 and MDM2. By CGH, DNA sequences from 17q were found to be amplified in 1 MII and 8 MIII, involving 17q23 in all cases. Despite the high frequency of chromosomal aberrations in the MII and MIII investigated, none of these tumors showed mutations in exons 5-8 of the TP53 gene. On the basis of the most common aberrations identified in the various malignancy grades, a model for the genomic alterations associated with meningioma progression is proposed.     

Chromosomal gains and losses in uveal melanomas detected by comparative genomic hybridization

Eleven uveal melanomas were analyzed using comparative genomic hybridization (CGH). The most abundant genetic changes were loss of chromosome 3, overrepresentation of 6p, loss of 6q, and multiplication of 8q. The smallest overrepresented regions on 6p and 8q were 6pter-->p21 and 8q24-->qter, respectively. Several additional gains and losses of chromosome segments were repeatedly observed, the most frequent one being loss of 9p (three cases). Monosomy 3 appeared to be a marker for ciliary body involvement. CGH data were compared with the results of chromosome banding. Some alterations, e.g., gains of 6p and losses of 6q, were observed with higher frequencies after CGH, while others, e.g., 9p deletions, were detected only by CGH. The data suggest some similarities of cytogenetic alterations between cutaneous and uveal melanoma. In particular, the 9p deletions are of interest due to recent reports about the location of a putative tumor-suppressor gene for cutaneous malignant melanoma in this region.     

Bronchial mucosal immunoreactivity of sensory neuropeptides in severe airway diseases

DNA copy number changes were investigated in 29 leiomyosarcomas by comparative genomic hybridization. The most frequent losses were detected in 10q (20 cases, 69%) and 13q (17 cases, 59%). The most frequent gains were detected in 17p (16 cases, 55%). The most frequent high-level amplifications were detected in 17p (7 cases, 24%) and 8q (6 cases, 21%). A total of 137 losses and 204 gains were detected. Small tumors (less than 5 cm in diameter) displayed fewer changes per sample (3 to 11; mean, 7) than the other tumors (4 to 22; mean, 13). There was an increase in the number of gains from small tumors (mean, 4) to very large tumors (>20 cm; mean, 10). However, the number of losses was similar in small, large, and very large tumors (mean, 4.5). Tumor size-related aberrations were observed. Gains in 16p were detected in all small tumors but were infrequent in large and very large tumors (27% and 11%, respectively). Similarly, gains and high-level amplifications in 17p were more common in small (80%) than in very large tumors (33%). Gains in 1q, 5p, 6q, and 8q were not seen in any of the small tumors but were detected in large and very large tumors. Gains in 6q and 8q occurred in 8 of 9 cases (89%) of very large tumors, 5 of them with a high-level amplification in 8q.     

Microsporidia of the genus Trachipleistophora--causative agents of human microsporidiosis: description of Trachipleistophora anthropophthera n. sp. (Protozoa: Microsporidia)

Only limited data are available on chromosomes specifically involved in prostatic tumour progression. This study has evaluated the cytogenetic status of primary prostatic carcinomas, local tumour recurrences, and distant metastases, representing different time points in prostatic tumour progression. Interphase in situ hybridization (ISH) was applied with a set of (peri) centromeric DNA probes, specific for chromosomes 1, 7, 8 and Y, to routinely processed tissue sections of 73 tumour specimens from 32 patients. Longitudinal evaluation was possible in 11 cases with local recurrence and nine cases with distant metastases. The remaining 12 patients showed no evidence of local recurrence or distant metastasis after radical prostatectomy on follow-up (mean 60.5 months) and served as a reference. Numerical aberrations of at least one chromosome were found in 27 per cent of the local recurrences and 56 per cent of the distant metastases. In decreasing order of frequency, +8, +7, and -Y were observed in the recurrences and +8, +7, -Y, and +1 in the distant metastases. Evaluation of the corresponding primary tumour tissue of the recurrence group showed numerical aberrations in 45 per cent of cases. The aberrations found were, in decreasing order of frequency, -Y, +7, and +8. In the concomitant primary tumour tissue of the distant metastasis group, numerical aberrations were detected in 67 per cent of cases. The aberrations most frequently encountered were +8, -Y, followed by +7. In four cases, a concordance was found between the primary tumour and its recurrence or distant metastasis. Discrepancies might have been caused by cytogenetic heterogeneity. Comparison of the primary tumour tissue of the reference, the recurrence, and the distant metastasis groups showed a significant increase for the percentage of cases with numerical aberrations (Ptrend = 0.02). Likewise, a trend was seen for gain of chromosome 7 and/or 8 (Ptrend < 0.05). The number of DNA aneuploid tumours also increased in these different groups (Ptrend = 0.03). These data suggest that cancers which recur in time display an intermediate position between tumours of disease-free patients and metastatic cancers.