Complex tumor-specific t(X;18) in seven synovial sarcoma tumors.

Cytogenetic analysis was performed of six monophasic synovial sarcomas (four primary, two recurrent tumors) and one recurrent poorly differentiated synovial sarcoma with complex tumor-specific t(X;18). In the complex translocations, besides chromosomes X and 18, the following chromosomes were involved: 1, 3, 5, 15, and 17. In all, taking these results together with findings of 20 previously published synovial sarcoma tumors with complex t(X;18), 13 different chromosomes were involved. Chromosomes 15 (22% of tumors) and 1, 5, and 12 (approximately 11% each) were the most frequently involved in complex translocation, but with different breakpoints. In our laboratories, complex tumor-specific t(X;18) ranged from 2.5% to 11.7% (average 6.5%) of synovial sarcoma karyotypes.

Clinical impact of molecular and cytogenetic findings in synovial sarcoma.

Synovial sarcoma is an aggressive soft-tissue tumor that accounts for up to 10% of soft-tissue sarcomas. Cytogenetically, synovial sarcoma is characterized by the t(X;18)(p11;q11), found in more than 95% of the tumors. This translocation results in rearrangements of the SYT gene in 18q11 and one of the SSX1, SSX2, or SSX4 genes in Xp11, creating a SYT/SSX1, SYT/SSX2, or SYT/SSX4 chimeric gene. It has been shown that patients with SYT/SSX1 fusion genes have a shorter metastasis-free survival than do patients with SYT/SSX2. Previous studies have also suggested that clonal evolution may be associated with disease progression. In the present study, RT-PCR analysis showed that all 64 examined synovial sarcomas from 54 patients had SYT-SSX chimeric genes. SYT/SSX1 was found in 40 tumors from 33 patients, SYT/SSX2 in 23 tumors from 20 patients, and SYT/SSX4 in one case. Two patients had variant SYT/SSX2 transcripts, with 57 bp and 141 bp inserts, respectively, between the known SYT and SSX2 sequences. Patients with tumors with SYT/SSX1 fusions had a higher risk of developing metastases compared to those with SYT/SSX2 fusions (P = 0.01). The reciprocal transcripts SSX1/SYT and SSX2/SYT were detected using nested PCR in 11 of the 40 samples with SYT/SSX1 and 5 of the 23 samples with SYT/SSX2, respectively. Among 20 blood samples, SYT/SSX1 and SYT/SSX2 were detected in one sample each. The t(X;18), or variants thereof, was found cytogenetically in all patients but three. Among 32 primary tumors, the t(X;18) or a variant translocation was the sole anomaly in 10. In contrast, of the seven metastatic lesions that were investigated prior to radiotherapy, only one had a t(X;18) as the sole anomaly; all other tumors displayed complex karyotypes. Cytogenetic complexity in primary tumors was, however, not associated with the development of metastases. Tumors with SYT/SSX2 less often (4/12 vs. 7/15) showed complex karyotypes than did tumors with SYT/SSX1, but the difference was not significant. Combining cytogenetic complexity and transcript data, we found that the subgroup of patients with tumors showing simple karyotypes and SYT/SSX2 fusion had the best clinical outcome (2/8 patients developed metastases), and those with tumors showing complex karyotypes together with SYT/SSX1 fusion the worst (6/7 patients developed metastases). This corresponded to 5-year metastasis-free survival rates of 0.58 and 0.0, respectively (P = 0.02).

Identification of two U937 cell sublines exhibiting different patterns of response to tumour necrosis factor.

The monocytic cell line U937 is a frequently used model in studies on the cytotoxic effect of tumour necrosis factor (TNF). Two sublines of this cell line, termed U937(G) and U937(M), revealing different patterns of response to this cytokine, have been identified. The U937(G) cells, similarly to the cells obtained from ATCC, were resistant to the cytotoxic action of TNF in the absence of the protein-synthesis blocker cycloheximide (CHX). The U937(M) cells, however, were sensitive to the cytotoxic action of TNF both in the presence and absence of cycloheximide. Genetic analysis of the U937 sublines confirmed their common origin. The described U937 sublines may be useful models for analysis of the mechanisms of response to TNF. Additionally, our observation underscores the variability of the U937 cell line, which is described by most authors as a TNF-sensitive line.

Spectral karyotyping reveals 17;22 fusions in a cytogenetically atypical dermatofibrosarcoma protuberans with a large marker chromosome as a sole abnormality.

The presence of an extra ring chromosome containing material from 17q and 22q, or, less frequently, a t(17;22)(q22;q13), is a cytogenetic hallmark of dermatofibrosarcoma protuberans (DFSP). However, occasionally tumors with other, atypical karyotypes are encountered. We describe a case of recurrent DFSP without a ring chromosome or a t(17;22) on standard cytogenetic analysis. In all cells analyzed by G-banding, an additional, large marker chromosome was present as a sole abnormality. This chromosome apparently included chromosome 8 or the 8q arm, but the origin of its remaining part could not be determined with certainty. To characterize further the abnormal chromosome, we applied spectral karyotyping (SKY). SKY confirmed the presence of an extra chromosome 8 or arm 8q in the marker and showed that its remaining part was composed of segments from chromosomes 7, 17, 21, and 22, with two copies of a 17;22 fusion. Our results and the literature data suggest that, in addition to a specific 17;22 fusion, amplification of material from chromosomes 17, 22, 8, 5, 7, and 21 may play a role in DFSP development and/or progression. Furthermore, our case demonstrates the usefulness of SKY in detection of a diagnostically relevant 17;22 fusion in DFSP patients who have unusual karyotypic features.

Cytogenetics of hepatoblastoma: further characterization of 1q rearrangements by fluorescence in situ hybridization: an international collaborative study.

BACKGROUND: Hepatoblastoma (HBT) is the most common hepatic neoplasm in children. This notwithstanding, little is known about pathogenetic factors, such as genetic abnormalities, of importance for the development and progression of this tumor type. To date, only 33 cytogenetically abnormal HBT have been published, and trisomies for chromosomes 2 and 20 have been shown to be the most frequent aberrations. Recently, unbalanced translocations involving proximal 1q have been described in several HBT, suggesting that a pathogenetically important gene maps to 1q. PROCEDURE: Six primary and one recurrent HBT were cytogenetically analyzed after short-term tissue culture. In addition, fluorescence in situ hybridization (FISH) studies, using locus-specific probes, were performed on three of these pediatric HBT as well as on one previously reported adult HBT. RESULTS: Total or partial trisomy 8, gain of chromosome 20, and structural rearrangements of chromosome 1 were detected in three HBT, and overrepresentation of chromosome 2 material was found in two HBT. The adjacent chromosome bands 1q12 and 1q21 were involved in three translocations, t(1;2), t(1;4), and t(1;11), which were all unbalanced and resulted in gain of 1q material. The previously reported adult HBT displayed 1q deletions with breakpoints at 1q12-21. FISH analyses of the 1q rearrangements revealed that all breakpoints were within the heterochromatic region. CONCLUSIONS: These findings provide further support for the importance of trisomies 2, 8, and 20 and rearrangements of 1q in the development of HBT. Furthermore, the consistent localization of breakpoints within the heterochromatic segment of chromosome 1 suggests that the important pathogenetic consequence of 1q abnormalities is the resulting genomic imbalance rather than a specific gene rearrangement.

Nonrandom chromosomal aberrations and cytogenetic heterogeneity in gallbladder carcinomas.

Chromosome banding analysis of 11 short-term cultured gallbladder carcinomas revealed acquired clonal aberrations in seven tumors (five primary and two metastases). Three of these had one clone, whereas the remaining four were cytogenetically heterogeneous, displaying two to seven aberrant clones. Of a total of 21 abnormal clones, 18 had highly complex karyotypes and three exhibited simple numerical deviations. Double minutes and homogeneously staining regions were observed in one and two carcinomas, respectively. To characterize the karyotypic profile of gallbladder cancer more precisely, we have combined the present findings with our three previously reported cases, thereby providing the largest cytogenetic database on this tumor type to date. A total of 287 chromosomal breakpoints were identified, 251 of which were found in the present study. Chromosome 7 was rearranged most frequently, followed by chromosomes 1, 3, 11, 6, 5, and 8. The bands preferentially involved were 1p32, 1p36, 1q32, 3p21, 6p21, 7p13, 7q11, 7q32, 19p13, 19q13, and 22q13. Nine recurrent abnormalities could, for the first time, be identified in gallbladder carcinoma: del(3)(p13), i(5)(p10), del(6)(q13), del(9)(p13), del(16)(q22), del(17)(p11), i(17)(q10), del(19)(p13), and i(21)(q10). The most common partial or whole-arm gains involved 3q, 5p, 7p, 7q, 8q, 11q, 13q, and 17q, and the most frequent partial or whole-arm losses affected 3p, 4q, 5q, 9p, 10p, 10q, 11p, 14p, 14q, 15p, 17p, 19p, 21p, 21q, and Xp. These chromosomal aberrations and imbalances provide some starting points for molecular analyses of genomic regions that may harbor genes of pathogenetic importance in gallbladder carcinogenesis. Genes Chromosomes Cancer 26:312-321, 1999.

A rare chimeric TLS/FUS-CHOP transcript in a patient with multiple liposarcomas: a case report.

Myxoid liposarcomas harbor a unique and specific t(12;16)(q13,p11) chromosomal translocation. The breakpoint has recently been identified, and involvement of the TLS/FUS gene on chromosome 16 and the CHOP gene on chromosome 12 was demonstrated. We report a case of a 45-year-old woman who developed multiple malignant lipomatous tumors of unknown origin and myxoid/round cell histology at different locations. To examine the diagnostic potential of this translocation and to develop a hypothesis on the origin of the tumors, we used cytogenetic and molecular cytogenetic methods (reverse transcription polymerase chain reaction, RT-PCR). We identified a chimeric RNA transcript in the second recurrence in the thigh/groin, as well as in another tumor in the mediastinum, which has an additional sequence of 33 bp, known as fusion transcript type III. Cytogenetic analysis of another tumor in retroperitoneal space revealed a rare type of unbalanced translocation der(16)t(12;16). We hypothesize that these tumors are metastases rather than multicentric tumors. The detection of the chimeric message in the present case is not only useful for differential diagnosis, but also for analyzing the origin of multiple neoplasms.

Cytogenetics of uterine sarcomas: presentation of eight new cases and review of the literature.

Tissue from 14 uterine tumor samples from eight patients-four with endometrial stromal sarcoma (ESS), two with leiomyosarcoma (ULMS), and two with malignant mixed mesodermal tumor (MMMT)-were investigated cytogenetically after short-term culturing. Clonal chromosome aberrations were found in 12 tumors. One ESS showed a recombination between 7p14 and 17q12, a rearrangement characterizing a subset of ESSs. In our series, chromosomes 1, 6, 7, and 16 were involved in structural aberrations most frequently (four cases each). Net loss of 6q material was found in four cases and bands 11q13, 16q13, and 22q13 were each rearranged in four cases. Among 43 uterine sarcomas, including 12 MMTs, now available for evaluation, some differences in breakpoint distribution among different tumor types were found. Rearrangements of bands 1p32, 3p24, and 10q22 were found exclusively in ULMS, whereas aberrations of bands 6p21, 7p21, and 17q12 were found predominantly in ESS.

Sarcomatoid carcinoma (carcinosarcoma) of the gallbladder.

We report a case of carcinoma of the gallbladder in a 67-year-old woman. The description comprises the histological, immunohistochemical, ultrastructural and cytogenetical picture of the tumor. The ultrastructural features as well as chromosomal changes may denote the epithelial derivation of the tumor studied.

Association of Klinefelter syndrome and abdominal teratoma: a case report.

Extragonadal germ cell tumors are rare. The association with Klinefelter syndrome has become observed recently. A case of an 11-month-old infant with Klinefelter syndrome and a retroperitoneal mature teratoma is presented. In the tumor and lymphocytes, a 47,XXY karyotype was found. The association of Klinefelter syndrome with germ cell tumors and its possible explanations are discussed.

Cytogenetic findings in an embryonal sarcoma of the liver.

An undifferentiated embryonal sarcoma (malignant mesenchymoma) of the liver from a 5-year-old girl was found to have near-triploid and near-hexaploid clones with several chromosomal rearrangements. This is the first description of the chromosomal changes in this tumor type.

Recurrent chromosome changes in two adult fibrosarcomas.

Cytogenetic analysis of two adult fibrosarcomas revealed clonal chromosomal rearrangements including unbalanced translocations between chromosomes 2 and 19, with the same segment, 2q21-qter, translocated onto 19p13 in one tumor and 19q13 in another; and partial monosomy of 10q due to add(10)(q22) and del(10)(q22q25) seen in one tumor each. This is the first description of nonrandom chromosomal changes in adult fibrosarcoma.