Clonal aberrations of chromosomes X, Y, 7 and 10 in normal kidney tissue of patients with renal cell tumors

Application of molecular diagnostic techniques to renal epithelial neoplasms

The application of molecular and cytogenetic techniques to the study of renal neoplasia has resulted in improved understanding of the biologic mechanisms that are responsible for tumor development and progression. It also revealed that several different and specific genetic events are responsible for tumorigenesis in the various categories and subcategories of renal tumors. The ultimate goal of research on the molecular pathology of renal neoplasms is a complete understanding of the genetics of these tumors, which will, in turn, aid in making the correct diagnosis, accurately assessing prognosis, and selecting appropriate and targeted therapeutic options.

Characterization of quantitative chromosomal abnormalities in renal cell carcinomas by interphase four-color fluorescence in situ hybridization

Renal cell carcinomas (RCC) in adults are histologically heterogeneous solid tumors with specific chromosomal abnormality patterns included in the World Health Organization (WHO) classification. To overcome some of the drawbacks of cytogenetic and comparative genomic hybridization (CGH) analyses, we designed a first-generation cytogenetic diagnostic test using four-color fluorescence in situ hybridization (FISH) on interphase nuclei. We selected 51 bacterial artificial chromosome and P1-derived artificial chromosome clones covering 17 chromosomal regions involved in the abnormalities of the adult RCC histologic subtypes. An initial set of probes allowed the identification of clear-cell RCC, papillary RCC, and other RCC on a single slide. A second test allowed the detection of additional chromosomal abnormalities or aberrations specific to chromophobic RCC and oncocytomas. We tested 25 cases of RCC, and the results were in agreement with those of cytogenetic techniques and/or CGH methods. The techniques appeared to be very sensitive, because small tumoral cell clones that were undetected by other cytogenetic methods were identified with this method. It was concluded that the multicolor FISH test was specific and sensitive, easy to perform, and could be part of the investigation process in RCC.

Cytogenetic and interphase FISH analyses of 73 basal cell and three squamous cell carcinomas: different findings in direct preparations and short-term cell cultures

Cytogenetic analysis performed on 73 sporadic basal cell carcinomas (BCCs) and three squamous cell carcinomas (SCCs) showed different findings in direct preparations (24 hours) and in short-term cell cultures. Except for loss of the Y chromosome, not one of the other clonal (+6, +16, add(2)(q37), del(3)(q13), add(1)(p31), and near triploidy) or sporadic changes found in direct preparations was found in cell cultures and vice versa. Clonal trisomy 6 found in two BCC direct preparations and demonstrated by interphase fluorescence in situ hybridization in 8 other cases seems to be a nonrandom change in basal cell carcinoma. Immunohistochemistry showed that the cell type investigated was different in the two methods of analysis used: epithelial in direct preparations and fibroblastic in cell cultures. Thus, the results obtained in direct preparations indicate the BCC or SCC epithelial karyotype, whereas the aberrations found in cell cultures indicate the presence of chromosome instability in the fibroblastic stroma. The apparent lack of correspondence between direct and indirect preparations and the presence of clonal chromosome changes in both epithelial and stromal cells suggest tumor cell heterogeneity of BCC. The fibroblastic stroma seems to be implicated in the neoplastic process. This is not evident in SCC, in which clonal changes are present only in direct preparations. The chromosomal distribution of the breakpoints involved in structural changes in direct and cell culture preparations is random; together with those reported in the literature, the breakpoints found in BCC cultures show, however, a cluster to 1p36, 3q13, 9q22, 14p11, 15p11, and Xp11 bands. We did not find any significant correlations between BCC cytogenetic results and the clinical data (site, age, sex, recurrence). The incidence of cases of BCC (38%) and of SCC (100%) showing clonal chromosome changes agree with their benign and malignant nature, respectively. Finally, a significantly high incidence of constitutional inv(9) and dup(9)(q11q21) was found in the group of patients with BCC.

Cytogenetic analysis of 11 renal oncocytomas: further evidence of structural rearrangements of 11q13 as a characteristic chromosomal anomaly

We carried out cytogenetic analysis on 11 renal oncotytomas by using G-banding and DAPI-banding techniques. Four of our tumors exhibited structural rearrangements affecting chromosome 11 at band q13. Together with another case previously described by us, our tumors constitute the largest series of renal oncocytomas displaying translocations involving 11q13. A review of the literature disclosed only 6 similar oncocytomas, 1 tumor with a t(9;11)(p23;q12), 2 tumors with a nearly identical t(9;11)(p23;q13), and 3 tumors with a t(5;11)(q35;q13). Therefore, our findings provide further cytogenetic evidence that genes located on 11q12-13 may be involved in the tumorigenesis of renal oncocytomas.

Chromosomal imbalances in papillary renal cell carcinoma: genetic differences between histological subtypes

Papillary renal-cell carcinoma (RCC) is a renal carcinoma variant with distinct gross, microscopic, and cytogenetic features. Recently, a type 1 (pale cytoplasm, small-cell) and a type 2 (eosinophilic cytoplasm, large-cell) subtype of papillary RCC have been described. Chromosomal alterations associated with these tumor types were examined in 25 papillary RCCs by comparative genomic hybridization. Relative copy number gains were frequently detected at chromosomes 7p (56%), 7q (44%), 12q (28%), 16q (32%), 17p (56%), 17q (76%), and 20q (32%). Chromosomal regions that were most often lost included 1p (24%), 4q (36%), 6q (40%), 9p (36%), 13q (36%), Xp (28%), Xq (36%), and Y (73%). There were clinical and genetic differences between the subtypes of papillary RCC. Type 2 tumors were of higher nuclear grade (P = 0.0012) and higher stage (P = 0.01) and had a worse prognosis (P = 0.03) than type 1 tumors. The number of DNA gains per tumor, especially gains of 7p and 17p, was significantly higher in type 1 than in type 2 tumors (P < 0.01). These data suggest the existence of two distinct morphological and genetic subgroups of papillary RCC. Losses of chromosome Xp were associated with short patient survival (P < 0.01). Despite the small number of cases, this finding suggests that a gene on chromosome Xp may contribute to papillary RCC progression.

Establishment and characterization of a human glioblastoma multiforme cell line

Cell lines provide a useful system for further understanding the biology of glioblastoma multiforme. In this study, a new glioblastoma multiforme cell line, GATAGM-96 (Gulhane Askeri Tip Akademisi-Gliblastoma Multiforme-96), was established from a tumor specimen removed from an 80-year-old male patient who underwent surgery for intracranial tumor. Morphologic examination, immunocytochemical staining, growth kinetics, and karyotypic characteristics of this cell line were studied. The cytoskeleton was positive for neuron-specific enolase, vimentin, and neurofilament, and it was negative for glial fibrillary acidic protein, S-100 protein, p53 protein, epidermal growth factor, and transforming growth factor alpha. Growth kinetic studies demonstrated an approximate population doubling time of 38 to 42 h and a colony forming efficiency of 83.3%. The karyotype of the cells demonstrated it as hyperdiploid, with a large subpopulation of polyploid cells. There were numerous structural and numerical chromosome aberrations; most of them were present as clonal events. The phenotypic and chromosomal features detailed on the GATAGM-96 cell line should make it a useful addition to the cell lines currently available for in vitro and in vivo studies of glioblastoma multiforme.

Cytogenetic investigations of 340 thyroid hyperplasias and adenomas revealing correlations between cytogenetic findings and histology

Cytogenetic analyses were performed on 340 follicular thyroid adenomas and goiters after short-term culture. Clonal chromosomal changes were found in 67 cases. Trisomy 7 as the sole abnormality or along with other trisomies was the most frequent type of aberration (19 cases). Other recurrent numerical changes were loss of chromosome 22 (4 cases) and the second X or the Y chromosome (5 cases). Translocations involving 19q13 (12 cases) were frequent structural chromosomal changes. Dicentric chromosomes or telomeric associations were frequent in goiters (12 cases). After a histopathologic classification of all cases, we have correlated the cytogenetic findings with the histology of the tumors. Only 8.4% of the goiters showed clonal abnormalities, whereas 44.9% of the adenomas revealed clonal abnormalities. Furthermore, simple clonal changes were predominantly found in goiters and complex changes in adenomas. The most impressive correlation was found in the group of lesions with trisomy 7. Although all but one lesion with one or two additional trisomies were goiters, those having three or more additional trisomies were all adenomas or adenomatous goiters.

Chromosome aberrations in renal tumors detected by fluorescence in situ hybridization

The aim of this study was to investigate the relationship between chromosome aberrations detected by fluorescence in situ hybridization (FISH) and tumor grade, stage, venous involvement, and DNA ploidy status in 18 renal tumors. Using FISH with chromosome-specific DNA probes, the copy number of pericentromeric sequences on chromosomes 3, 7, 9, and 17 was detected within interphase nuclei in touch preparations from tumor specimens. Monosomy for chromosome 3 was detected in seven of 9 DNA diploid tumors, whereas all DNA aneuploid tumors demonstrated trisomy or tetrasomy for chromosome 7. Moreover, monosomy for chromosome 3 was more frequently shown in the diploid and low-stage tumors than in the aneuploid and high-stage tumors. The percentage of hyperdiploid cells significantly correlated with DNA ploidy status in the case of chromosomes 3 and 7 (p = 0.030, p = 0.007, respectively). The percentage of hyperdiploid cells for chromosome 3 had borderline significance with tumor stage. On the other hand, the percentage of diploid cells for chromosome 17 was significantly correlated with DNA ploidy status and tumor stage (p = 0.030, p = 0.027, respectively). Moreover, the percentage of diploid cells for chromosome 7 in renal cell carcinoma (RCC) with venous involvement was significantly lower than those without venous involvement (p = 0.023). These results suggest that the incidence of chromosomal aberrations detected by FISH is more frequent than the chromosomal aneuploidy reported previously by conventional cytogenetics. Therefore, loss of chromosome 3 may be associated with an early event in RCC carcinogenesis. Gain of chromosomes 3 and 7 is correlated with tumor progression as well as gain and loss of chromosome 17. Study of the chromosomal aberrations may provide a greater understanding of tumor carcinogenesis and progression in RCC.

Giant cell tumor of tendon sheath is a polyclonal cellular proliferation

Giant cell tumor of tendon sheath (GCTTS) is a common soft tissue tumor. Immunophenotypical evidence suggests it is of synovial cell origin. There is controversy regarding the underlying nature of this lesion, specifically whether it is a neoplastic or nonneoplastic (ie, reactive or hyperplastic) process. Karyotypic abnormalities have been identified in GCTTS and interpreted as evidence of neoplasia, although the finding of similar karyotypic abnormalities in unequivocally nonneoplastic proliferations raises questions about using such findings to define a neoplasm. In an attempt to resolve this uncertainty, a polymerase chain reaction (PCR)-based assay for methylation of the X-linked human androgen receptor gene (HUMARA) was used to assess whether GCTTS is a clonal or polyclonal proliferation. DNA was isolated from formalin-fixed, paraffin-embedded tissue blocks from eight cases of digital GCTTS in female subjects; two cases of hepatocellular carcinoma (HCC) were used as clonal controls. Seven of eight cases of GCTTS were informative, and each showed a polyclonal proliferation, whereas both cases of HCC were clonal. Our results indicate that GCTTS is a nonneoplastic proliferation, if one accepts that a population of cells forming a tumorous mass must show clonality to be classified as a neoplasm. Our results emphasize that simple karyotypic abnormalities do not define a neoplasm. It remains to be determined whether GCTTS is a reactive or hyperplastic process.

Cytogenetic classification of renal cell cancer

Cytogenetic and molecular genetic investigations in cancer are important tools to address problems of oncogenesis and tumor progression, of classification, and of diagnosis of tumors. A combination of advanced molecular genetic, cytogenetic, and (immuno) histopathologic analysis will contribute significantly to the elucidation of the oncogenic steps that lead to immortalization and subsequent malignant behavior. In this review written on the occasion of Dr. Avery Sandberg's 75th anniversary, we will present a model for the pathogenesis of renal cell tumors based on a new cytomorphologic classification and our (cyto)genetic analysis of about 175 renal cell tumors, together with the accumulated data in the literature.

Cytogenetic abnormalities and microsatellite instability in endometrial adenocarcinoma

Recently various authors described a new mechanism involved in the genesis of some tumors, which is characterized by a tendency for replication mistakes and by genomic instability of microsatellite repeats. This instability can be revealed through the shift in the electrophoretic mobility of the analyzed fragments, which is due to a different number of repeat units. This phenomenon is widely documented in colorectal tumors of patients affected by hereditary nonpolyposis colorectal carcinoma (HNPCC). We performed a cytogenetic and molecular study of 23 endometrial adenocarcinomas to investigate the presence of genomic instability and to evaluate the possibility of a positive correlation with specific chromosomal changes. The study of genomic instability was performed using 23 microsatellites localized over 8 chromosomes. Genomic instability of microsatellites was observed in 3 cases over all 8 analyzed chromosomes. The tumoral stage of cases with microsatellite instability does not differ significantly from the remaining tumors. As a matter of fact several cases showing no evidence of instability were more advanced (II B, III A) than tumors with instability. In ten cases we observed trisomy of chromosome 10, in some as a sole anomaly. The 3 cases with genomic instability revealed a near-diploid karyotype and all showed the presence of a supernumerary marker derived from chromosome 1 rearrangements. A derivative chromosome 1 was revealed in 4 cases without evidence of microsatellite instability. It should be noted that the presence of many unidentified markers and the small number of tumors with instability do not allow us to give a definitive significance to this observation. Our results indicate that there is not an apparent correlation between microsatellite instability and specific chromosomal abnormalities. Moreover, we did not find any correlation between pathological characteristics of the tumor and genomic instability. Microsatellite instability appears to be a relatively rare event in endometrial carcinoma.

Complex translocation [7;22] identified in an epithelioid hemangioendothelioma

We describe a malignant epithelioid hemangioendothelioma arising in the back of a 45-year-old man with pulmonary and bone marrow metastases. Light microscopic and immunohistochemical features of this tumor are presented. Karyotyping revealed several clonal abnormalities: a complex unbalanced translocation [7;22] involving multiple breakpoints (confirmed by fluorescence in situ hybridization), a Robertsonian t(14;14), and loss of the Y chromosome. Monosomy for chromosome 11 was noted in a subset of the tumor cells. To our knowledge a karyotype has not been previously reported for this unusual vascular tumor.

Chromophilic renal cell carcinoma: cytomorphological and cytogenetic characterisation of four permanent cell lines

Chromophilic renal cell carcinoma is a distinct type of human renal cancer, only recently recognised and defined by its characteristic histomorphological aspect and cytogenetic aberrations. We are the first to report on the establishment and cytogenetic characterisation of a panel of four permanent cell lines, i.e. chromphi-1, -2, -3 and -4, derived from strictly defined renal cell carcinomas (RCCs) of the chromophilic type and kept in continuous culture for up to 5 years. Immunohistochemistry revealed coexpression of vimentin and cytokeratins in all cell lines the cytokeratin polypeptide patterns, however, varying between the different cell lines. By light and transmission electron microscopy, various amounts of cytoplasmatic glycogen deposition were observed, being most pronounced in chromphi-3 and -4. The mean population doubling time ranged from 24 h (chromphi-1) to 51 h (chromphi-4). Chromphi-1 tumour cells produced slowly growing tumours in nude mice using the subrenal capsule assay. In all cell lines, cytogenetic analysis revealed numerical chromosomal aberrations known to be characteristic for chromophilic RCCs, i.e. loss of the Y chromosome, tri- or tetrasomy of chromosomes 7 and 17 as well as various combinations of additional structural and numerical chromosomal aberrations. Karyological aberrations were least pronounced in chromphi-2 and most complex in chromphi-1. Chromosomal aberrations typically affecting the short arm of chromosome 3 in clear cell RCCs were not observed in any of our cell lines.

No FISH evidence for trisomy 7 in normal or leukemic bone marrow

Trisomy 7 has been found as the sole chromosomal anomaly in both benign and malignant tumors, as well as in nonneoplastic lesions. It has been reported that +7 may occur in tumor-infiltrating as well as in peripheral T cell and in the thymus. The precursor cells, which mature in the thymus to T lymphocytes, originate in the bone marrow and the present study was undertaken to investigate whether cells carrying an extra chromosome 7 can be detected there. Bone marrow samples from five hematologically normal individuals and 12 children with acute lymphoblastic leukemia (ALL) were analyzed by interphase fluorescence in situ hybridization (FISH) using a chromosome 7 centromere-specific probe. Half of the ALLs were karyotypically normal, whereas the other half displayed clonal abnormalities (one pseudodiploid and five hyperdiploid karyotypes, none of which had +7). The FISH analysis showed no evidence of cells with trisomy 7 in the bone marrow samples from the controls or ALLs. This suggests that the gain of a chromosome 7 by T lymphocytes does not occur before the bone marrow precursor cells are conditioned in the thymus.

Papillary renal cell carcinoma: quantitation of chromosomes 7 and 17 by FISH, analysis of chromosome 3p for LOH, and DNA ploidy

Papillary renal cell carcinoma (papillary RCC) is an uncommon histologic variant of RCC with distinct gross, microscopic, and immunohistochemical features. Recent karyotypic analyses suggest that papillary RCC differs from other types of RCC at the genetic level as well. Whereas nonpapillary (clear cell, granular cell) RCC is characterized by deletions in chromosome 3p, papillary tumors reportedly exhibit a pattern of chromosomal trisomies, typically including chromosomes 7 and 17. To further examine the relationship between overrepresentation of these chromosomes and papillary histology, archival material from 36 papillary tumors was subjected to fluorescence in situ hybridization (FISH) analysis using alpha-satellite repeat probes specific to 7 and 17. Excess signals for chromosome 17 were detected in 22 of 28 (78%) low-grade papillary tumors (Fuhrman nuclear grades 1 and 2), and in seven of eight (87%) high-grade tumors (grades 3 and 4). Correlation of chromosome 17 FISH signals with karyotypes performed on two low-grade and three high-grade tumors was excellent. Among the cases without evidence of excess chromosome 17 were three unusual papillary tumors with sclerotic and hyalinized fibrovascular cores. In two cases, comparison was made of FISH signals from multiple, separate gross nodules of tumor; concordance for trisomic 17 signals was observed in one case, but not in the other. Chromosome 7 signals were overrepresented in all seven papillary tumors examined. DNA ploidy was determined in 19 of the 36 tumors; a relationship between DNA ploidy and polysomy 7 or 17 was not apparent. To examine the possible role of chromosome 3p deletions in the development of papillary RCC, 11 cases were studied for loss of heterozygosity (LOH) at one or more loci in the region of 3p13-21. Only three of the 11 cases had LOH at these loci. The findings are discussed with respect to the development and progression of papillary RCC.

Constellation of congenital abnormalities in an infant: a new syndrome or tissue-specific mosaicism for trisomy 18?

A newborn infant born to consanguineous (first cousin) parents was noted to have complex congenital heart defect and minor anomalies suggestive of trisomy 18. Blood lymphocyte and skin fibroblast karyotypes were normal. He died in the neonatal period of postoperative complications. On interphase fluorescence in-situ hybridization (FISH) using autopsy specimens, a significant number of cells in the liver (17%) were trisomic for chromosome 18, compared to normal control liver tissue. However, interphase FISH analyses of blood lymphocytes, skin fibroblasts, and kidney tissue were normal. It is our opinion that this apparent mosaicism for trisomy 18 in the patient's liver may be spurious, though it brings into focus the issue of possible tissue/organ-specific mosaicism. The anomalies in this infant do not resemble a previously described malformation syndrome. Parental consanguinity raises the possibility that this represents a new autosomal recessive malformation syndrome.

Proliferation enhancement by spontaneous multiplication of chromosome 7 in rheumatic synovial cells in vitro

Mosaic trisomy of chromosome 7 is known to occur in a variety of non-neoplastic hyperproliferative disorders. In long-term cell cultures established from rheumatic synovium with mosaic trisomy 7, we observed a continuous increase in the proportion of cells with trisomy 7 to over 50% by the 10th in vitro passage. Simultaneous in situ hybridization with a repetitive chromosome-7-specific DNA probe and fluorescent Ki-67 labelling showed a strong correlation between trisomy 7 and an elevated proliferation index in cultured rheumatic synovial cells. Moreover, we observed a fraction of rapidly proliferating cells with up to eight copies of chromosome 7 as the sole cytogenetic change. Frequent somatic pairing of centromeres of two chromosomes 7 in interphase nuclei suggests either atypical non-disjunction with a persisting centromere or selective endoreduplication of chromosome 7.

Chromosomal abnormalities in non-neoplastic renal tissue

Chromosome aberrations were studied in short-term cultures of non-neoplastic renal tissue and tumor tissue in 60 patients, 41 male and 19 female, with renal cell cancer (RCC), and in normal renal parenchyma from two cases, one male and one female, at autopsy with non-kidney related disease. Cytogenetic analysis of the non-neoplastic renal tissue from the patents with RCC revealed clonal chromosome aberrations in 32 of 60 (53%) cases: -Y, +Y, +X, +5, +7, +10, +12, +13, +18, +21, and del(9)(q12). In all other cases, non-clonal numerical and structural chromosome aberrations were observed, except for three cases of culture failure. Forty-two cases of RCC yielded clonal chromosomal abnormalities. Trisomy 7 was present in 23 cases, loss of Y in 14, trisomy 5 and 12 in three, trisomy 18 in two cases, and trisomy 10 in one case. Clonal chromosomal anomalies found in two cases from kidneys without neoplasia were trisomy 7, trisomy 12, and trisomy 18 in one case, and monosomy of chromosome 15 in the other. The proportion of aberrant cells in both cases (with clonal and non-clonal aberrations) was, on average, 24%. Apparently, chromosomal abnormalities only play a role in the process of oncogenesis when they are in the appropriate stage and lineage of differentiation.

In situ hybridization to chromosomes stabilized in gel microdrops

Conventional chromosome in situ hybridization procedures rely on fixation to glass slides followed by microscopic evaluation. This report describes the development of a microdrop in situ hybridization to chromosomes in suspension. Chromosomes encapsulated in gel microdrops (GMDs) composed of an agarose matrix withstood stringent hybridization and denaturation conditions. Because of the increased stability, hybridization to encapsulated chromosomes was detected by flow cytometry as well as conventional microscopy. Thus, the MISH method offers a means for chromosome hybridization without slides and may enable identification and isolation of chromosome using hybridization rather than nucleic acid binding dyes.

Clonal chromosome changes in non-neoplastic ureters

Cytogenetic analysis was performed on 23 samples from non-neoplastic ureters. Clonal chromosome abnormalities were found in eight. They were: loss of Y chromosome, as a single abnormality (five cases) or associated with trisomy 10 and 20 (one case) or with trisomy 2 (one case); and duplication of Y chromosome (one case). Different numerical and structural sporadic abnormalities were found in nine cases. Immunohistochemical analysis and direct observation using the inverted microscope showed that the cells were mainly of the fibroblastic type. FISH analysis with chromosome 7 alpha-satellite probes failed to detect the presence of trisomy 7 in three epithelial cases tested.

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.

Comprehensive allelotyping of human renal cell carcinomas using microsatellite DNA probes

The von Hippel-Lindau locus on chromosome 3p is a tumor suppressor gene known to be involved in nonpapillary renal cell carcinoma. A previous loss of heterozygosity (LOH) study aimed at determining the allelotype of kidney tumors has indicated that in addition to 3p, chromosome arms 5q, 6q, 10q, 11q, 17p, and 19p may also harbor tumor suppressor genes. However, cytogenetic studies reveal that chromosomes 3p, 6q, 8p, 9pq, and 14q most frequently undergo karyotypic changes in renal tumors. To resolve these differences, a collection of microsatellite DNA probes has been used to scan for LOH so that 90% of individual tumor genomes were rendered informative for allele loss. The assay is capable of detecting quantitative genomic alterations in tumor cells as well. We find that LOH is most frequent for chromosome arm 3p. However, in no tumor is 3p exclusively affected. LOH for 6q, 8p, 9pq, and 14q is also distinctly elevated for both nonpapillary as well as papillary tumors and suggest that many of the tumor suppressor loci involved may be common to the etiology of both forms of kidney cancer.

Epidermal growth factor receptor gene expression and binding capacity in renal cell carcinoma, in relation to tumor stage, grade and DNA ploidy

Epidermal growth factor receptor (EGFr) was studied in 19 renal cell carcinomas using competitive binding analysis and solution hybridization assay. EGFr binding capacity and EGFr mRNA expression were significantly higher in tumors in comparison with kidney cortex tissues. The EGFr binding capacity was higher in diploid than in aneuploid tumors. No differences in binding capacities or mRNA expression between different tumor grades or stages were demonstrated. It was concluded that EGFr is overexpressed in renal cell carcinoma, although with no relationship to tumor characteristics.

Absence of trisomy 7 in nonneoplastic human ascitic and pleural fluid cells. An interphase cytogenetic study

Trisomy 7 is a frequent aneuploid change in lymphomas, adenocarcinomas, and malignant mesenchymal and neurogenic tumors. Moreover, it has been observed in cultured and uncultured non-neoplastic cells from brain, kidney, liver, lung, and atherosclerotic plaques, among other tissues, opening debate on the role of this change in normal and neoplastic tissue. We used nonradioactive in situ hybridization (ISH) with a biotinylated chromosome 7-specific alpha-satellite DNA probe to seek an extra copy of chromosome 7 in ascitic and pleural fluid interphase cells from 26 donors. The donors comprised 24 patients with nonmalignant clinical history, one patient with non-Hodgkin's malignant lymphoma (positive control), and one patient with chronic myeloid leukemia (CML, negative control). The highest frequency of fluid cells with three hybridization signals in patients without neoplasia was 0.5%, in contrast to the frequency of 40.5% noted in the fluid cells of the patient with non-Hodgkin's malignant lymphoma. The results demonstrate that the frequency of trisomic cells in pleural as well as in ascitic fluid is very low, making possible use of the cells in ascitic or pleural fluids in identification of malignancy.

Two-phase short-term culture method for cytogenetic investigations from human prostate carcinoma

An improved technique for primary short-term culture of prostate carcinoma cells in two phases, with and without serum, for subsequent cytogenetic analysis is reported and compared with four other methods. After mechanical disaggregation and a brief collagenase treatment of tumor specimens, cell clusters were seeded in RPMI 1640 and 15% fetal calf serum (FCS) without any other supplement in the first phase. The culture medium was changed to a serum-free medium supplemented with bovine pituitary extract (BPE) and epidermal growth factor (EGF) when the first outgrowth became apparent. During this second phase, fibroblast growth could be virtually abolished within 48 hr. The epithelial and prostatic origin of the cultured cells was confirmed by immunocytochemical methods in each culture. Metaphase analysis revealed chromosome aberrations in over 80% of cases (both clonal and nonclonal alterations) indicating the presence of neoplastic cells. Clonal numerical chromosome aberrations, found by conventional cytogenetic analysis, were used to provide the reliability of the culture system in interphase nuclei of corresponding uncultured tumor tissue by fluorescence in situ hybridization (FISH). The main points of the described method are: 1) combined mechanical/enzymatic disaggregation, 2) seeding of the disaggregated cell clumps rather than of single cells, 3) initialization of the cultures in RPMI 1640 medium with 18% FCS without any other supplements, and (4) stimulating of selective epithelial proliferation by changing the culture conditions through serum-free medium.

Nonrandom numerical aberrations of chromosomes 7, 9, and 10 in DNA-diploid bladder cancer

Double-target in situ hybridization technique (ISH) was applied to 37 cases of bladder cancer to detect numerical aberrations of chromosomes 7, 9, 10, and 11 by centromeric DNA probes. Of 33 evaluable cases, 29 (88%) demonstrated chromosome aberrations. In 17 cases with diploid pattern as measured by flow-cytometric DNA analysis (FCM), 15 (88%) demonstrated chromosome aberrations. Of these, trisomy 7, monosomy 9, and trisomy 10 were detected in three, three, and one case, respectively, as a single chromosome aberration. In 14 (88%) of 16 cases with an aneuploid DNA pattern, chromosome aberrations for two or more chromosomes were demonstrated. A significant correlation was observed between grade of chromosome aberrations and tumor grade (p < 0.01, Fisher's test), between number of spots for chromosome 7 and peak value in FCM (p = 0.015, by Spearman rank order test). In eight cases, chromosome aberrations in the tumor were compared with the corresponding pattern in the grossly normal and histologically benign mucosa. Trisomy 10 and monosomy 9 were detected as chromosome numerical aberrations in the histologically normal mucosa, consistent with aberrations in the corresponding patients. We conclude that trisomy 7, monosomy 9, and trisomy 10 may be early events in the evolution of bladder cancer.

Cytogenetic observations in 13 cystadenolymphomas (Warthin's tumors)

The cytogenetic findings in 13 cultured Warthin's tumors (papillary cystadenoma lymphomatosum) are reported. Only one case showed an abnormal stemline. This was pseudodiploid and characterized by three different reciprocal translocations and one deletion. Small abnormal sidelines, however, were seen in three additional cases. All except one of the 12 tumors with a normal stemline contained variant cells. These showed a variety of numerical and/or structural aberrations. From this study it is obvious that to determine whether or not cytogenetically distinctive subgroups actually exist in cystadenolymphomas (as in pleomorphic adenomas) the number of cases must be greatly amplified.

Cytogenetic findings in squamous cell carcinoma of the oral cavity

A case of squamous cell carcinoma (SCC) of the oral cavity is presented which, in addition to normal metaphases, cytogenetically displayed two cell clones with chromosomal aberrations: 46,XY,1+del(5)(q13),der(18)t(5;18)(q13;p11),-5 and 49,XY,+5,+7,+10 After a review of the literature of the few cytogenetically analyzed cases, the findings confirm the multiclonal origin of oral SCC and also the commonly seen aberrations of chromosome 5.

Development of papillary renal cell tumours is associated with loss of Y-chromosome-specific DNA sequences

Twenty-two papillary renal cell tumours were analysed by Southern hybridization using eight DNA probes from homologous regions of the X and Y chromosomes and two Y-chromosome-specific DNA probes. Sixteen of the 19 papillary renal cell tumours of male patients showed the loss of Y-chromosome-specific sequences. No loss of heterozygosity was detected in three tumours that developed in females. The frequency of loss of the Y chromosome was established in 50 non-papillary renal cell carcinomas as well. Only seven of the 31 non-papillary renal cell carcinomas obtained from male patients had lost the Y-chromosome-specific sequences, whereas no allelic loss was found in 19 non-papillary tumours obtained from female patients. Papillary renal cell tumours show a strong male preponderance (6:1) and loss of Y chromosome in 84 per cent of the cases, whereas non-papillary renal cell carcinomas show only a slight male preponderance (1.5:1) and the Y chromosome is lost in only 22 per cent of the cases. These data suggest that a tumour suppressor gene is localized at one of the homologous regions of the X and Y chromosomes, the homozygous inactivation of which is associated with the development of papillary renal cell tumours.

Chromosome studies in 70 brain tumors with special attention to sex chromosome loss and single autosomal trisomy

Chromosome analysis was performed on 70 brain tumors. Thirty-six tumors showed clonal karyotypes characterized by many autosomal abnormalities; 20 meningiomas revealed monosomy 22 as a consistent abnormality, and 12 gliomas showed various abnormalities frequently involving chromosomes 3, 7, and 22. Of the remaining 34 tumors, 24 had normal karyotypes and 10 had clonal cells with loss and/or an extra sex chromosome with single trisomy of chromosomes 3, 6, 7, or 14. Sex chromosome aneuploidy was mostly due to loss of the Y or an X chromosome and was observed in 25 tumors, usually together with autosomal abnormalities. In these tumors the average frequency of cells with sex chromosome aneuploidy was 52%, with a range from 12% to 100%. Loss of the Y was found significantly more frequently in tumors of aged patients. Chromosome analysis in materials subcultured for a long period showed a tendency for cellular selection in which clonal cells with many autosomal abnormalities disappeared rapidly and karyotypes having loss or an extra sex chromosome and/or trisomy 7 were present in an increasing proportion with advance of cell generations in vitro. We infer that the cells having loss of one sex chromosome or trisomy 7 have a proliferative advantage. And that cells bearing only these abnormalities may exist in normal brain tissue more abundantly than in any other body tissue. The possibility of tissue-specific aneuploid mosaicism in the normal tissue would allow an alternative interpretation for simple autosomal trisomy in solid tumors.

Identification of a yeast artificial chromosome that spans the human papillary renal cell carcinoma-associated t(X;1) breakpoint in Xp11.2

Recently, a specific chromosome abnormality, t(X;1)(p11;q21), was described for a subgroup of human papillary renal cell carcinomas. The translocation breakpoint in Xp11 is located in the same region as that in t(X;18)(p11;q11)-positive synovial sarcoma. We used fluorescence in situ hybridization (FISH) and somatic cell hybridization techniques to demonstrate 1) that the Xp11 translocation breakpoint in papillary renal cell carcinoma differs from that observed in synovial sarcoma and has a more proximal location, and 2) that an ornithine aminotransferase (OAT)L2 containing yeast artificial chromosome (YAC) spans the X;1 translocation. This YAC provides an ideal starting point from which the breakpoint itself and the gene(s) involved can be isolated and characterized.

Cytogenetic analysis of epithelial renal-cell tumors: relationship with a new histopathological classification

Renal-cell carcinomas (RCC) are clinically, histologically and cytogenetically very heterogeneous. The present histological WHO classification shows no clear correlation between histologic subtypes and specific chromosomal abnormalities. In 1986, a new classification was proposed by Thoenes and Störkel based on the cell type from which the tumor arises. They distinguish 5 cell types: clear-cell, chromophilic, chromophobic, ductus Bellini and oncocytic. Results of 105 primary tumors show that, in this new classification, there is a correlation between different subtypes of renal-cell tumor and specific chromosomal abnormalities at a microscopic and/or molecular level. The clear-cell compact type shows structural aberrations of chromosomes I, 3, 4, 5q, 6, 10q, 11q and 12q, together with polysomy of chromosomes X, 4, 5, 7, 10, 12, 15, 16, 19, 20, 21 and 22, monosomy of chromosomes 3, 8, 9, 13, 14, and loss of Y. The main characteristics of the chromophilic tubulo-papillary type are trisomies 7 and 17, and loss of the Y-chromosome. Chromophobic carcinoma seems to be correlated with, inter alia, polysomy 7, trisomies 12, 16, 18, 19, structural abnormalities of 11q, and telomeric associations. Oncocytomas do not reveal any specific chromosomal anomaly, except for trisomy 7. Loss of heterozygosity on 3p is only found in the clear-cell compact type. Some specific chromosomal abnormalities correlate with a particular grade of the tumor. These correlations support the hypothesis that specific chromosomal abnormalities play a role in the histogenesis and oncogenesis of RCC. They may be important for tumor diagnosis and clinical prognosis.

Defining the extent and nature of cytogenetic events in prostatic adenocarcinoma: paraffin FISH vs. metaphase analysis

A comparative study of primary prostatic tumors utilizing conventional metaphase analysis of prostate tumor cultures and fluorescence in situ hybridization (FISH) analysis of paraffin-embedded tissue sections revealed significant differences in type and extent of cytogenetic aberrations. Clonal trisomy 7 was identified in two tumors by metaphase analysis of prostate cultures, but not confirmed in either case by FISH analysis. True gain of chromosome 8 was revealed by FISH analysis in malignant epithelium of four tumors but not in adjacent normal or hyperplastic glands. Neither gain nor loss of this chromosome was observed by metaphase analysis in any of the tumors. Significant monosomy and nullisomy of chromosome 10 was identified in one case by FISH, but no cells with gain or loss of chromosome 10 were observed by metaphase analysis. Significant loss of the Y chromosome was revealed in one tumor by FISH, but no cells with -Y were identified by metaphase analysis. Clonal loss of the Y chromosome was identified in two other tumors by metaphase analysis. Paraffin FISH analysis of these tumors revealed overall monosomy in both, although in one tumor there was extensive nodular loss of the Y chromosome. Paraffin FISH analysis permits identification of cytogenetic aberrations in areas identified as carcinoma (CaP), prostatic intraepithelial neoplasia (PIN), and benign prostatic hyperplasia (BPH). This technique appears more informative in defining the true extent and nature of cytogenetic aberrations in prostate cancer than metaphase analysis of prostate tumor cultures.

Fluorescence in situ hybridization

Spectacular advances in the use of fluorescence in situ hybridization (FISH) for the visualisation of specific DNA sequences in metaphase chromosomes and interphase cells have been made over the last few years making the technique a useful tool in clinical research. One of the biggest impacts has been in the field of detection and diagnosis of human malignancies. Chromosomal translocations, deletions, amplification of specific genes and changes in chromosome number can all be detected in the non-dividing interphase nucleus using probes ranging from whole chromosome 'paints' to individual gene specific probes. Gene mapping has also benefited from advances in FISH technology. Target sequences ranging from one to several hundred kilobases can be visualised on metaphase chromosomes and spatial resolution in interphase cells permits the ordering of two probes over a distance as small as 1000 base pairs. The potential uses of FISH continue to increase with each new technical innovation.

Gliosis specimens contain clonal cytogenetic abnormalities

The relevance of sex chromosome aneusomy and trisomy 7 in neoplastic brain tissue is controversial. For better understanding of the relative importance of these anomalies, we made a conventional cytogenetic study of cells from tissue obtained from patients who underwent partial cerebral resection for a seizure disorder. Each specimen exhibited "gliosis," but none contained histologically identifiable tumor cells. Sixty-six specimens were analyzed by routine cytogenetic methods. Nonclonal abnormalities were observed in 11.6% of the cells (86% of cases) analyzed. In 11 cases, however, simple clonal karyotypes were observed. Of these cases, six involved loss of a Y chromosome and three involved loss of an X chromosome. Among the cases with loss of an X chromosome, two exhibited multiple abnormal clones. One of these cases had trisomy 7 as well as trisomy 18, and another had a supernumerary psu dic(15)(q13). The supernumerary chromosome was constitutional. One patient had possible Klinefelter syndrome. An additional case had a clonal del(10)(q23) that may have resulted from a hereditary fragile site. We conclude that although some of the apparently acquired clonal and nonclonal abnormalities may be due to a consistent in vitro artifact, it is probable that they are present in the brain tissue itself. Whatever the cause, caution should be used in interpretating cytogenetic abnormalities observed in brain tumor specimens.

Trisomy 7 in nonneoplastic cells

The somatic mutation theory of tumorigenesis states that mutations are necessary for tumor development. On the other hand, acquired, clonal chromosomal alterations are occasionally detected in otherwise normal, nonneoplastic cells--for example, loss of sex chromosomes occurs in bone marrow cells and lymphocytes in elderly individuals--and it is therefore evident that not all mutations are by themselves sufficient for neoplasia to occur. Thus, the finding of an acquired, clonal chromosomal abnormality does not constitute proof that a lesion is neoplastic. Trisomy 7 has, as the sole clonal chromosomal aberrations, been reported in a wide variety of epithelial tumor types but also in some mesenchymal and neurogenic neoplasms. It has been suggested to be a primary, i.e., tumor-initiating, abnormality in tumors of the bladder, brain, colon, kidney, lung, ovary, prostate, and thyroid. But data from cytogenetic studies of solid tumors, macroscopically normal tissue in the proximity of solid tumors, and nonneoplastic lesions now question the importance of a solitary +7 as a neoplasia-associated change. Most solid tumors in which trisomy 7 has been found as the sole change in one clone have also displayed other, cytogenetically unrelated, clones with complex karyotypic abnormalities. Such karyotypic differences among coexisting clones could indicate that the neoplasm is polyclonal, that the cytogenetically disparate clones have emerged during tumor progression from one original clone carrying submicroscopic genomic changes only, or that the clone with +7 does not represent the tumor parenchyma. The latter interpretation is supported by the finding of cells with trisomy 7 in macroscopically normal tissue outside tumors of the brain, kidney, and lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Clonal chromosome aberrations in cell cultures of synovial tissue from patients with rheumatoid arthritis

Cytogenetic analysis of primary cell cultures and/or passages 1-3 of synovial tissue from seven patients with rheumatoid arthritis was performed. As the only recurrent chromosome aberration, trisomy 7 was found in six of seven cultures. In four cultures, trisomy 7 occurred as a clonal change in up to 20% of the analyzed cells, with an increase of the proportion of cells with +7 with the duration of the in vitro culture. Apart from this recurrent change, a variety of partly clonal, partly nonclonal numerical and structural chromosome aberrations were observed in all cases. These findings support the view that clonal chromosome aberrations may play a role in the pathogenesis of invasive growth of the synovial tissue in rheumatoid arthritis although the localized synovial hyperproliferation is not a true neoplastic process.

Cytogenetic analysis of six bronchial carcinoids

Short-term cultures from four typical and two atypical primary bronchial carcinoids were cytogenetically analyzed. A lung metastasis from one of the atypical carcinoids was also analyzed. Of the four typical carcinoids, two had normal chromosome complements, while the other two had the karyotypes 46,X, -X, +7/47,XX, +7/47,XX, +X/46,XX and 47,XX, +7/46,XX. Both atypical carcinoids had chromosome abnormalities. One had the karyotype 45-46,X, -X,del(1)(q32),add(17)(p13), +add(19)(p13), -22, +r/47,XX, +X. The second carcinoid had the karyotype 78-81,XXY, +Y, +1,t(2;8)(q21;q24), +3, +4, +del(4) (q25), +5, +6,der(6)t(6;6)(q21;p21)x2, +7, +7, -10,add(14)(p11-13), +19, -21, +1-4mar. The metastasis from this carcinoid had the same aberrations, except that the del(4)(q25) had been lost and one to two markers had been gained.

Chromosome analysis of 20 breast carcinomas: cytogenetic multiclonality and karyotypic-pathologic correlations

Short-term cultures from 20 breast carcinomas were analyzed cytogenetically. A normal female chromosome complement was found in 4 cases. Clonal chromosome aberrations were detected in 16 tumors. In 10 tumors, multiple cytogenetic clones were found; in 2 cancers the clones were related, reflecting clonal evolution, but in the remaining 8 tumors the clones were cytogenetically unrelated, indicating clonal heterogeneity in the origin of the tumor parenchyma. Correlation analysis between karyotypic and pathologic parameters indicated that cases with complex karyotypes and/or cytogenetically unrelated clones, when compared with cases with a single simple karyotypic abnormality, were generally of higher histologic malignancy grade, had more mitoses in the histologic sections, and also more often had carcinoma in situ lesions in the same breast.

Complementarity of interphase and metaphase chromosome analysis in human renal tumors

Fluorescence in situ hybridization (FISH) was used as a complement to earlier cytogenetic studies of human renal tumors. Chromosome-specific para-centromeric probes were applied to cells disaggregated from tissue blocks of tumors, fresh samples from which had yielded cytogenetic results after short-term culture. Cells were dissociated from thick sections of paraffin-embedded, formalin-fixed tissues. Biotin-labeled probes specific for chromosomes 1, 3, 7, 11, 12, 15, 17, and the Y chromosome were applied in individual cases and were detected by fluorescence. Probes for chromosomes 1, 7, and 17 yielded clean signals with disomic control frequencies near 90%, and 97% of controls showed a single bright spot for the Y chromosome. The 9 cases selected all provided ample numbers of dissociated cells which were hybridized successfully, although some chromosomal signals were poor in individual cases. Abnormal copy numbers of chromosomes 1 and/or 17, not identified in culture, were observed in 7 cases. Trisomy 7 observed in culture was substantiated by FISH on the original tissues, as was loss of the Y, in each of 4 cases, respectively. Our results include limited validation of culture cytogenetics, evidence of selection in culture of tumor subpopulations, and demonstration that interphase cytogenetics by FISH is applicable to archival tissue blocks after prolonged periods of storage. Conditions of culture before harvest and inherent heterogeneity within tumors permit selection for nonrepresentative subgroups within tumors and emphasize the need for multiple approaches to evaluation.

Clonal chromosome changes in renal carcinoma do not correlate with clinical stages and histopathologic grades

We analyzed the correlations between chromosome abnormalities and clinical and histopathologic characteristics in 77 cases of renal cell carcinoma (RCC). Chromosome changes such as +5,+7,+8,+10,+18,+X,+Y, and -Y have been excluded from the analysis because they also occur in nonneoplastic kidney tissue and cytogenetic analysis indicates that these anomalies are not involved in tumor progression. The most frequent specific chromosome abnormalities in this sample were 3p rearrangements, trisomy 17, and hyperdiploidy and were not related to tumor stage or grade or to development of distant metastases.

Trisomy 7 and trisomy 10 characterize subpopulations of tumor-infiltrating lymphocytes in kidney tumors and in the surrounding kidney tissue

We performed conventional cytogenetic analysis and fluorescence in situ hybridization in short-term cultures of normal and neoplastic kidney tissues. Cell populations carrying an extra chromosome 7 or an extra chromosome 10 as the only chromosome change could be identified in kidney tumors, mostly renal cell carcinomas, and in the surrounding kidney tissue, but not in nonneoplastic kidneys. To identify the type of cells displaying these aneuploidies, we performed in situ hybridization (ISH) with probes specific for the centromeric region of chromosomes 7 and 10 on frozen kidney tissue sections. Trisomy 7 and trisomy 10 were restricted to infiltrating inflammatory cells in the tumor as well as in the surrounding tissue. Trisomy 7 and trisomy 10 were also found in subpopulations of peripheral blood T cells of cancer patients and of normal individuals, as well as in the thymus of five normal fetuses (21-29 weeks), but not in noninvaded reactive lymph node sections of patients without malignancy. When lymphocytes were enriched from kidney tumors and surrounding tissue by either Ficoll/Hypaque density gradient or immunomagnetic selection with anti-CD3, anti-CD4, or anti-CD8 monoclonal antibodies, it was confirmed that they contained a high percentage of trisomy 7 and trisomy 10 cells. Further proof for T-lymphocyte origin of the trisomy 7 and trisomy 10 cells was obtained by simultaneous staining of lymphocytes isolated from tumor tissue with anti-CD3, anti-CD4, and anti-CD8 monoclonal antibodies and ISH. We conclude that trisomy 7 and trisomy 10, found in renal carcinomas and surrounding kidney tissue, characterize subpopulations of tumor-infiltrating lymphocytes. The biologic significance of this phenomenon is unknown and requires further investigation.

Trisomy 7 in nonneoplastic focal steatosis of the liver

Cytogenetic analysis of short-term cultures of a nonneoplastic focal steatosis of the liver showed trisomy 7 as the sole chromosomal change. This finding, especially when viewed in light of previous reports describing +7 in nonneoplastic tissues, strongly suggests that trisomy 7 cannot be considered a tumor-specific abnormality when it occurs as the only change. The cell type in which +7 is present is not yet known.