Abstract
Aim
To investigate overall chromosomal alterations using array‐based comparative genomic hybridisation (CGH) of myxoid liposarcomas (MLSs) and myxofibrosarcomas (MFSs).
Materials and methods
Genomic DNA extracted from fresh‐frozen tumour tissues was labelled with fluorochromes and then hybridised on to an array consisting of 1440 bacterial artificial chromosome clones representing regions throughout the entire human genome important in cytogenetics and oncology.
Results
DNA copy number aberrations (CNAs) were found in all the 8 MFSs, but no alterations were found in 7 (70%) of 10 MLSs. In MFSs, the most frequent CNAs were gains at 7p21.1–p22.1 and 12q15–q21.1 and a loss at 13q14.3–q34. The second most frequent CNAs were gains at 7q33–q35, 9q22.31–q22.33, 12p13.32–pter, 17q22–q23, Xp11.2 and Xq12 and losses at 10p13–p14, 10q25, 11p11–p14, 11q23.3–q25, 20p11–p12 and 21q22.13–q22.2, which were detected in 38% of the MFSs examined. In MLSs, only a few CNAs were found in two sarcomas with gains at 8p21.2–p23.3, 8q11.22–q12.2 and 8q23.1–q24.3, and in one with gains at 5p13.2–p14.3 and 5q11.2–5q35.2 and a loss at 21q22.2–qter.
Conclusions
MFS has more frequent and diverse CNAs than MLS, which reinforces the hypothesis that MFS is genetically different from MLS. Out‐array CGH analysis may also provide several entry points for the identification of candidate genes associated with oncogenesis and progression in MFS.
The recent development of cancer cytogenetics has helped to clarify the mechanisms underlying the tumorigenesis of soft‐tissue sarcomas. Myxoid liposarcoma (MLS) is the second most common subtype of liposarcoma, accounting for more than one third of all liposarcomas and representing about 10% of all adult soft‐tissue sarcomas.1 It constitutes one of the major myxoid malignancies of the soft tissue along with myxofibrosarcoma (MFS). It is sometimes difficult to distinguish MLS from other myxoid tumours, particularly MFS. A unique chromosome translocation, t(12;16) (q13;p11), resulting in a fusion of the segments of the DDIT3 gene (also known as CHOP or GADD153) on chromosome 12 and the FUS (also referred to as TLS) on chromosome 16, is the key genetic aberration in MLS.2 More than 90% of MLSs are cytogenetically characterised by this translocation.3
MFS, also known as a myxoid variant of malignant fibrous histiocytoma (MFH), is one of the most common sarcomas known to affect elderly people. The karyotypic abnormalities in MFH, including its myxoid variant, are usually complex, and multiple numerical and structural rearrangements are frequently found in this type of soft‐tissue sarcoma.4 However, no chromosomal aberrations specific to MFH or MFS have been identified so far, although telomeric associations, ring chromosomes and dicentric chromosomes are often seen in MFH.5
Conventional chromosomal comparative genomic hybridisation (CGH) can detect chromosomal imbalances of the whole genome by a single analysis, and it is also useful in obtaining a bird's eye view of the DNA copy number alterations in the whole tumour genomes. Knowledge of DNA copy number aberrations (CNAs) may facilitate identification of oncogenes and CNAs can be used for tumour classification.6 The recently developed, array‐based CGH technique allows a high throughput analysis of copy number changes at high resolution throughout the whole genome and also provides information on genomic regions near the centromere or telomere, which are often difficult to detect by conventional CGH.7 Moreover, a gain or loss of DNA copy number detected by array CGH may directly reflect increased or decreased expression of the corresponding gene, and the loci or regions showing high frequencies of copy number gains or losses suggest the presence of oncogenes or tumour suppressor genes. Although the most frequent approaches used to screen tumours for genomic dosage alterations are fluorescence in situ hybridisation and CGH, the application of these two methods is limited, partly because of their poor resolution and the need for high‐quality metaphase spreads.
No detailed genomic profiles of MFS or MLS using array‐based CGH have been so far available in the literature. We investigated the overall DNA copy number alterations of MLS and MFS by using array‐based CGH.
Materials and methods
Materials and DNA extraction
Cases of MLS and MFS were retrieved from the files of the Department of Pathology and Oncology, School of Medicine, University of Occupational and Enviromental Health, Kitakyushu, Japan. The diagnosis of each case was made according to currently used morphological criteria.1 In brief, MLSs were diagnosed by the presence of lipoblasts at varying stages of differentiation and stellate or spindle mesenchymal cells, associated with a prominent plexiform capillary network and an abundant myxoid matrix (fig 1A). MFSs were characterised by variable myxoid stroma, cellular pleomorphism and a distinctively curvilinear vascular pattern (fig 1B). We found 10 patients with MLSs and 8 with MFSs. Table 1 summarises their clinical features. Four patients with MLSs were proved to have the FUS–DDIT3 fusion gene, by nested reverse transcription‐polymerase chain reaction, or t(12;16)(q13;p11), by cytogenetic analysis.8,9
Figure 1 Representative histological features of (A) myxoid liposarcoma and (B) myxofibrosarcoma. (A) Myxoid liposarcoma is composed of spindle or stellate cells and lipoblasts with a plexiform capillary network and an abundant myxoid matrix. (B) Myxofibrosarcoma is made up of atypical and pleomorphic tumour cells with no evidence of lipoblastic differentiation.
Table 1 Clinical data of patients with myxoid tumours.
| Sex | Age (years) | Site | Size (cm) | Specimen | Histological subtype | |
|---|---|---|---|---|---|---|
| Myxoid liposarcoma | ||||||
| Case 1* | M | 38 | Thigh | 5×2 | Recurrence | Myxoid |
| Case 2* | M | 25 | Thigh | 5×3 | Recurrence | Myxoid |
| Case 3 | M | 48 | Thigh | 10×4 | Recurrence | Myxoid |
| Case 4† | F | 48 | Retroperitoneum | 17×10 | Recurrence | Myxoid |
| Case 5 | M | 34 | Shoulder | 15×15 | Primary | Myxoid |
| Case 6 | F | 46 | Thigh | 7×6 | Primary | Myxoid |
| Case 7 | F | 48 | Thigh | 13×9 | Primary | Myxoid and round cell |
| Case 8 | M | 50 | Thigh | 3×2 | Recurrence | Myxoid |
| Case 9† | M | 73 | Thigh | 18×11 | Primary | Myxoid |
| Case 10 | M | 61 | Thigh | 3×5 | Recurrence | Myxoid |
| Myxofibrosarcoma (myxoid MFH) | ||||||
| Case 11‡ | M | 69 | Retroperitoneum | 12×9 | Primary | Intermediate grade |
| Case 12‡ | M | 44 | Lower leg | 4×2 | Primary | High grade |
| Case 13 | M | 81 | Hand | 3×2 | Primary | Intermediate grade |
| Case 14 | F | 66 | Lower leg | 7×4 | Primary | Low grade |
| Case 15 | F | 46 | Elbow | 5×4 | Primary | Intermediate grade |
| Case 16 | M | 61 | Lower leg | 4×3 | Primary | Intermediate grade |
| Case 17 | F | 60 | Lower leg | 4×3 | Primary | Intermediate grade |
| Case 18 | M | 61 | Upper arm | 2×1 | Recurrence | Low grade |
F, female; M, male; MFH, malignant fibrous histiocytoma.
*The FUS–DDIT3 fusion gene was detected in these cases by nested reverse transcription‐polymerase chain reaction.
†Two cases with myxoid liposarcoma were proved to have t(12;16)(q13;p11) by cytogenetic analysis using short‐term cultures of tumour cells.
‡The FUS–DDIT3 fusion gene was not detected in either of the two cases by nested reverse transcription‐polymerase chain reaction.
Genomic DNA was obtained from snap‐frozen tumour tissue specimens according to standard procedures using proteinase K digestion and phenol–chloroform extraction. Normal DNA was isolated from the lymphocytes of healthy men and women donors as a reference for two‐colour hybridisations.
DNA microarray slide
We used commercially available genomic DNA microarray slides (MacArray Karyo1400, Macrogen, Seoul, South Korea) that were developed for use in microarray‐based CGH assays. The microarray contains 1440 target DNA clones (bacterial artificial chromosome clones, including 356 cancer‐related genes) covering the entire human genome and representing regions important in cytogenetics and oncology. Approximately 2 ng of each bacterial artificial chromosome DNA clone comprising the desired target sequences are arrayed in target spots of 17.5×26 mm diameter, and each clone is represented by three target spots.
Fluorescence labelling of sample DNA and hybridisation
Array‐based CGH was carried out according to the manufacturer's protocols (Macrogen Inc., Seoul, South Korea). Briefly, tumour DNA and reference DNA were labelled with Cy3‐2′‐deoxyuridine 5′‐triphosphate (Amersham, Tokyo, Japan) and Cy5‐2′‐deoxyuridine 5′‐triphosphate (Amersham), by the random‐priming method using a Random Priming Labelling Kit (Invitrogen, Tokyo, Japan). DNAs labelled with fluorochromes were mixed with Cot‐1 DNA, denatured at 75°C for 15 min, and then incubated at 37°C for 1 h. The hybridisation mixture was then introduced into the hybridisation chamber of the microarray slide, which was incubated at 37°C for 72 h. After removing the hybridisation chamber from the microarray slide, the slides were rinsed twice in washing solution (50% formamide/2×SSC) at 46°C and were then transferred into 2×SSC solution and air dried.
The hybridised and washed microarray slides were then captured with a universal microarray reader system, Genepix 4000A (Axon Instruments, Foster City, California, USA) and analysed with an analysis software specifically developed for the present array‐based CGH (ArrayAnalysis, Macrogen). Test (Cy3):reference (Cy5) fluorescence ratio of each sample was determined automatically by using the software. The increase and decrease of sample DNA copy number were determined as thresholds set at log2 ratios of 0.25 and −0.25, respectively, according to the standard protocol provided by the manufacturer (Macrogen; fig 2). Amplification (high‐level gain) was defined by a log2 ratio threshold >0.5 as described previously.10
Figure 2 (A) Whole genomic profile of myxofibrosarcoma (case 16) and (B) detailed profile of chromosome 8. Thresholds for copy number gains and losses are shown at log2 ratios of 0.25 and −0.25, respectively. Amplicons of distal 8q are present in combination with proximal amplicons to this region (B).
Results
Table 2 and fig 3 summarise the array CGH findings in myxoid tumours analysed in our study. CNAs were found in all of the eight MFSs and three MLSs. The remaining seven MLSs lacked detectable genomic imbalances.
Table 2 Areas of gain and loss.
| Gain | Loss | |
|---|---|---|
| Myxoid liposarcoma | ||
| Case 1 | – | – |
| Case 2 | – | – |
| Case 3 | – | – |
| Case 4 | – | – |
| Case 5 | – | – |
| Case 6 | 5p13.2–p14.3, 5q11.2–5q35.2 | 21q22.2–qter |
| Case 7 | 8p21–p23, 8q | – |
| Case 8 | – | – |
| Case 9 | – | – |
| Case 10 | 8p21.2–p23.3, 8q11.22–q12.2, 8q23.1–q24.3 | – |
| Myxofibrosarcoma (myxoid MFH) | ||
| Case 11 | 1q21.2–q25.2 | – |
| Case 12 | 1q23, 7q33–q35, 15q14–q15.2 | 1q31–qter, 2p12–pter, 2q14.2–qter, 3p11–p22, 3q12.1–q21.3, 3q24–qter, 4p , 4q, 5p13.1–p15.33, 8p11, 8p21–p23, 10q21.1–q26.2, 11p11.1–p15.4, 11q22.2–qter, 12p11.2–p13.3, 12q14.2–q24.21, 13q, 16q, 17q11.2–q12, 20p |
| Case 13 | – | 13q12.11–q34, Yq11.2 |
| Case 14 | 7p21–p22.1, 9q33–q34, 12p13.32–pter, 12q13–qter, 17p11.2, 17q12–qter, 19p, 19q13, Xp11.2, Xq12 | 20p11.21–p12.3, 20q12–q13.2, 21q21.3–q22.2, 22q11 |
| Case 15 | 4q13–q25, 9q22.31–q22.33, 10q24.1–q26.1, 11p15.4–pter, 13q14.3–q22.2, 21q22.3, 22q11.1–q11.23 | 10p11.23–p14, 11p11–p14, 14q31 |
| Case 16 | 1p13.3–p32.1,1p36–pter, 4p15–pter, 5p, 5q11.2–q22.3, 7p21–p22, 8p, 8q11.22–q21.12, 8q24–qter, 12p13.32–pter, 12q15–q21.1, 12q24.12–q24.23, 14q32.3, 18p11.21–pter, 19q13, 20q, 21q22.3, Xp11.2–p22.3, Xq12–q26.3, Xq28–qter | 2q32.3–q37.3, 4q12–q35.2, 6q13–q16, 10p12.31–pter, 11p11–p14, 11q23.3–q25, 12p12.3–p13.31, 13q14.3–qter, 14q24–q31, 20p, 22q12.1 |
| Case 17 | 3p11.2–p14.2, 4q31–qter, 7p13–p22, 7q22.3–q31.31, 9q22.31–q32, 12q13.3–q21.32, 14q24–q31, 16q12–q22, 17q22–q23.3 | 10q25–q26, 17q11, 21q11.2–q22.2 |
| Case 18 | 1p36, 3p12, 3q12.3–q13.21, 5p12–p13.3, 5q11.2–q14.3, 6p24.3–p25, 7p, 7q21, 7q32.2–qter, 8p11–p23, 8q11–q21.2, 9p11.2–p21.1, 9q21.33–q33.1, 11q22, 12p11–p12.1, 12p13.32–pter, 12q13–qter, 14q, 15q22–q26, 17p11.2–p13.3, 17q21.33–qter, 20q13.13, 22q13.1–q13.31, Xp11.2–p22.2, Xq12–q13, Xq24–qter | 1p22.3–p35, 3p25.3–pter, 3q27–qter, 4q32–qter, 6p12.1–p21.2, 10p13–pter, 10q21.1–q26.1, 11q13.5–q22, 11q23–q25, 13q11–q34, 15q11–q21, 16q22.2–q23.2, 18p, 18q12.1–qter, 21q22.13–q22.3, Yq |
–, none; MFH, malignant fibrous histiocytoma.
Figure 3 Summarised gains and losses of the DNA copy number in 10 myxoid liposarcomas, as shown by thin dotted lines, and 8 myxofibrosarcomas shown by thick lines. The losses are shown on the left and gains on the right. Each line represents a genetic aberration seen in one sample.
In MFS, the CNAs detected most often were gains at 7p (the minimal common region 7p21.1–p22.1) and 12q (12q15–q21.1) and a loss at 13q (13q14.3–q34). These alterations were seen in 4 (50%) MFSs. The second most frequent CNAs were gains at 7q (the minimal common region 7q33–q35), 9q (9q22.31–q22.33), 12p (12p13.32–pter), 17q (17q22–q23), Xp (Xp11.2) and Xq (Xq12), and losses at 10p (10p13–p14), 10q (10q25), 11p (11p11–p14), 11q (11q23.3–q25), 20p (20p11–p12) and 21q (21q22.13–q22.2), which were detectable in 3 (38%) MFSs. Several recurrent chromosomal imbalances in MFS were found in every histological grade. Tables 3 and 4 depict the clones with gains or losses for the putative cancer‐related genes in at least three MFSs. In addition, 42 clones containing cancer‐related genes, including murine double minutes 2 (MDM2), PDGFRA and MET, previously described as candidate genes of MFH associated with oncogenesis or progression, were gained in 2 of the 8 MFSs. Table 5 shows the amplifications (high‐level gain) for all of the clones in the cases with MFS.
Table 3 Gain at chromosomal region and localised cancer genes in myxofibrosarcoma.
| Region | Cancer genes | Cases with gain (%)* |
|---|---|---|
| 4q11 | AFP | 4/8 (50) |
| 7q33–q35 | TIM1 | 4/8 (50) |
| 8p11.2 | POLB | 3/8 (38) |
| 8q24.3 | TG | 3/8 (38) |
| 12p11.2 | krag | 3/8 (38) |
| 12p13 | CCND2 | 4/8 (50) |
| 12q15 | HMGIC | 3/8 (38) |
| 17q23 | TBX2 | 3/8 (38) |
| 19p13.3 | SH3GL1 | 3/8 (38) |
| Xp21.1 | OTC | 3/8 (38) |
| Xq12 | ED1 | 4/8 (50) |
| Xq13.1 | TED | 4/8 (50) |
*Alterations were defined by the log2 ratio thresholds of 0.25 for copy number gain. Using this threshold, we generated a frequency table. Clones with amplifications in at least three tumours are shown, based on the order of their chromosomal position.
Table 4 Loss at chromosomal region and localised cancer genes in myxofibrosarcoma.
| Region | Cancer genes | Cases with loss (%)* |
|---|---|---|
| 1q43 | Akt3 | 5/8 (62) |
| 2p12 | REG1A | 3/8 (38) |
| 2p23 | ALK | 3/8 (38) |
| 2q21 | CXCR4 | 3/8 (38) |
| 3p14.2 | FHIT | 3/8 (38) |
| 3q26 | MDS1 | 3/8 (38) |
| 4q21–q25 | IBSP | 4/8 (50) |
| 6q27 | PDCD2 | 3/8 (38) |
| 10p15.1 | DNMT2 | 3/8 (38) |
| 10q24 | PLAU | 3/8 (38) |
| 10q24 | HOX11 | 3/8 (38) |
| 10q25.1–q25.2 | FACL5 | 4/8 (50) |
| 10q25.3–q26.1 | DMBT1 | 4/8 (50) |
| 11p11.2 | KAI1 | 3/8 (38) |
| 11q23 | PIG8 | 3/8 (38) |
| 11q25 | ADAMTS8 | 3/8 (38) |
| 12p13.3–p11.2 | LRP6 | 3/8 (38) |
| 12q15 | HMGIC | 3/8 (38) |
| 12q22 | BTG1 | 4/8 (50) |
| 17q11.2–q12 | LIG3 | 4/8 (50) |
| 20p11 | JAG1 | 3/8 (38) |
| Xq22 | PLP | 3/8 (38) |
*Alterations were defined by the log2 ratio thresholds of −0.25 for copy number loss. Using this threshold, we generated a frequency table. Clones with deletions in at least three tumours are shown, based on the order of their chromosomal position.
Table 5 High‐level amplifications in myxofibrosarcoma.
| Region | Loci names | Cases with high‐level amplifications (%)* |
|---|---|---|
| 2p23.2 | D2S1980 | 2/8 (38) |
| 8p11 | MOZ | 2/8 (38) |
| 8q11.22 | SHGC‐153 877 | 2/8 (38) |
| 8q23.1 | D8S1638 | 3/8 (38) |
| 8q24.3 | TG | 2/8 (38) |
| 12q24.12 | SHGC‐68 495 | 2/8 (38) |
| 12q24.13 | WI‐12 136 | 2/8 (38) |
| 17q21.2 | HER‐2 (ERBB2) | 2/8 (38) |
| 17q23 | TBX2 | 2/8 (38) |
| 21q21.2 | SHGC‐8256 | 2/8 (38) |
| Xq28 | MECP2 | 2/8 (38) |
| Xp11.23 | SHGC‐144 705 | 3/8 (38) |
| Xq12 | ED1 | 4/8 (50) |
*Alterations were defined by the log2 ratio thresholds of 0.5 for high‐level amplification. Using this threshold, we generated a frequency table. Clones with amplifications in at least two tumours are shown, based on the order of their chromosomal position.
In two MLSs, CNAs detected were gains at 8p21.2–p23.3, 8q11.22–q12.2 and 8q23.1–q24.3. Gains at 5p13.2–p14.3 and 5q11.2–5q35.2 and a loss at 21q22.2–qter were seen in the other MLSs. No high‐level amplifications were observed in the MLSs.
Discussion
MFS and MLS should be distinguished from each other because of their distinct biological behaviours and potentially different clinical treatments. More than 90% of MLSs are cytogenetically characterised by a unique chromosome translocation, t(12;16) (q13;p11).3 However, in a small number of previous CGH studies of myxoid or round‐cell liposarcomas, genomic imbalances were observed less frequently than in other subtypes of liposarcoma.11,12,13
Schmidt et al11 reported that only 8 of the 17 patients with myxoid or round‐cell liposarcomas showed changes in DNA copy number, and 4 of the 8 tumours had gains of 13q without any high‐level gain (amplification). The other CGH studies of myxoid or round‐cell liposarcomas reported an amplification of chromosome 8 as the most frequent chromosomal aberration.12,13 These observations were in line with ours: 3 (30%) of the 10 MLSs showed DNA copy number changes in our study, and 2 of them had copy number changes in chromosome 8, with no high‐level gains in any. These findings suggest that MLS is mainly characterised by structural aberrations that occur at a chromosome level, but may not disrupt the genomic DNA balance.
By contrast, complex cytogenetic changes are frequently detected in MFH.14,15,16 Some recurrent changes and possible candidate genes associated with MFH have been identified in previous cytogenetic and CGH studies. It has also been suggested that 7q32 is a possible sign of an adverse prognosis and that the loss of chromosome 13 is the most common chromosomal imbalance.14,15 However, the cytogenetic information on MFS is still limited except for a single CGH study by Idbaih et al,16 who reported that the most frequent gains affecting chromosome subregions or pericentromeric regions of 1, 5p, 19p, 19q and 20q and losses in 1q, 2q, 3p, 4q, 10q, 11q and 13q were also recurrently found.
In our study, MFSs were shown to have recurrent chromosome imbalances; the most frequent gains were seen at 7p and 12q, and a loss at 13q. In chromosome 12q, tumour‐associated genes or oncogenes such as sarcoma amplification sequence, human homologue of MDM2, cyclin‐dependent kinase 4 and high‐mobility group protein IC have been shown to be amplified in MFH.17 MDM2 presumably functions as a cellular regulator and mediator of the tumour suppressor protein p53, and increased levels of MDM2 may functionally inactivate p53.18 Support for this hypothesis comes from studies showing that one third of MFHs had MDM2 amplification and one third had mutations of p53, including homozygous loss, rearrangements and point mutations.19,20 In our analysis, the gain of DNA containing high‐mobility group protein IC was identified in 3 of the 8 MFSs, and that of MDM2 in 2. No clone representing cyclin‐dependent kinase 4 was included in the array used. In chromosome 13q, we found at least three putative tumour suppressor genes: endothelin receptor type B (13q22), retinoblastoma 1 (13q14) and breast cancer susceptibility gene (13q12). Alterations to retinoblastoma 1 are a frequent finding in a variety of cancers, including MFH.21 Stratton et al19 reported that abnormalities of the p53 gene were found in several classes of soft‐tissue sarcoma, including MFH, and also showed that abnormalities of the retinoblastoma 1 suppressor gene and of the p53 gene often occur together, thus indicating that the coincidental inactivation of more than one tumour suppressor gene may, in some cases, be required for tumour development.19 Thus, MFS is often associated with the genomic imbalance of various chromosome regions, which may harbour genes important for oncogenesis and progression.
Because of the high resolution of the array CGH used, we could detect previously undescribed alterations in the chromosomal regions, such as 7p21.1–p22.1 and 7q33–q35, in MFS. These regions include several genes that are likely candidate genes in other malignant neoplasms. The TIM1 gene is located in 7q33–q35, which was one of the most frequently gained regions in our study. TIM1 belongs to the Dbl family of guanine nucleotide exchange factors for ρ‐guanine‐5′ triphosphatases and is specifically expressed in breast tumours, suggesting its role in breast tumour progression. Genes at 7p21.1–p22.1, such as those encoding interleukin 6, which increases vascular endothelial growth factors and angiogenesis in gastric carcinoma, TWIST as a critical regulator of prostate cancer cell growth and an ETS transcription factor ER81, which is regulated by oncogenic human epidermal growth factor receptor‐2/Neu and activator of thyroid and retinoic‐acid receptor in mammary tumorigenesis, may be related to the development of MFS.22,23,24,25 The genetic pathways and molecular targets associated with the development and progression of MFS are complicated and still remain controversial. Further detailed studies are necessary to clarify the genetic pathway of the development of MFS.
In conclusion, array‐based CGH is a feasible and valuable technique that allows us to delineate clearly the genotypes of MLS and MFS. Our study has identified several recurrent genetic imbalances in MFSs, but not in MLSs. These results support the notion that MFS is a myxoid soft‐tissue sarcoma with a distinct genetic background from MLS and may provide some entry points for the identification of candidate genes associated with the oncogenesis or progression of MFS.
Abbreviations
CGH - comparative genomic hybridisation
CNAs - copy number aberrations
MDM2 - murine double minutes 2
MFH - malignant fibrous histiocytoma
MFS - myofibrosarcoma
MLS - myxoid liposarcoma
Footnotes
Competing interests: None declared.
References
- 1.Fletcher C D M, Unni K, Mertens F.World Health Organization classification of tumours. Pathology and genetics of tumours of soft tissue and bone. New York: IARC Press, 2002
- 2.Kuroda M, Ishida T, Horiuchi H.et al Chimeric TLS/FUS‐CHOP gene expression and the heterogeneity of its junction in human myxoid and round cell liposarcoma. Am J Pathol 19951471221–1227. [PMC free article] [PubMed] [Google Scholar]
- 3.Fletcher C D, Akerman M, Dal Cin P.et al Correlation between clinicopathological features and karyotype in lipomatous tumors. A report of 178 cases from the Chromosomes and Morphology (CHAMP) Collaborative Study Group. Am J Pathol 1996148623–630. [PMC free article] [PubMed] [Google Scholar]
- 4.Nishio J, Iwasaki H, Ishiguro M.et al Establishment of a new human malignant fibrous histiocytoma cell line, FU‐MFH‐1: cytogenetic characterization by comparative genomic hybridization and fluorescence in situ hybridization. Cancer Genet Cytogenet 200314444–51. [DOI] [PubMed] [Google Scholar]
- 5.Mandahl N, Heim S, Arheden K.et al Rings, dicentrics, and telomeric association in histiocytomas. Cancer Genet Cytogenet 19883023–33. [DOI] [PubMed] [Google Scholar]
- 6.Mohapatra G, Moore D H, Kim D H.et al Analyses of brain tumor cell lines confirm a simple model of relationships among fluorescence in situ hybridization, DNA index, and comparative genomic hybridization. Genes Chromosomes Cancer 199720311–319. [DOI] [PubMed] [Google Scholar]
- 7.Beheshti B, Park P C, Braude I.et al Microarray CGH. Methods Mol Biol 2002204191–207. [DOI] [PubMed] [Google Scholar]
- 8.Aoki T, Hisaoka M, Kouho H.et al Interphase cytogenetic analysis of myxoid soft tissue tumors by fluorescence in situ hybridization and DNA flow cytometry using paraffin‐embedded tissue. Cancer 199779284–293. [DOI] [PubMed] [Google Scholar]
- 9.Hisaoka M, Tsuji S, Morimitsu Y.et al Detection of TLS/FUS‐CHOP fusion transcripts in myxoid and round cell liposarcomas by nested reverse transcription‐polymerase chain reaction using archival paraffin‐embedded tissues. Diagn Mol Pathol 1998796–101. [DOI] [PubMed] [Google Scholar]
- 10.de Leeuw R J, Davies J J, Rosenwald A.et al Comprehensive whole genome array CGH profiling of mantle cell lymphoma model genomes. Hum Mol Genet 2004131827–1837. [DOI] [PubMed] [Google Scholar]
- 11.Schmidt H, Bartel F, Kappler M.et al Gains of 13q are correlated with a poor prognosis in liposarcoma. Mod Pathol 200518638–644. [DOI] [PubMed] [Google Scholar]
- 12.Parente F, Grosgeorge J, Coindre J M.et al Comparative genomic hybridization reveals novel chromosome deletions in 90 primary soft tissue tumors. Cancer Genet Cytogenet 199911589–95. [DOI] [PubMed] [Google Scholar]
- 13.Szymanska J, Tarkkanen M, Wiklund T.et al Gains and losses of DNA sequences in liposarcomas evaluated by comparative genomic hybridization. Genes Chromosomes Cancer 19961589–94. [DOI] [PubMed] [Google Scholar]
- 14.Larramendy M L, Tarkkanen M, Blomqvist C.et al Comparative genomic hybridization of malignant fibrous histiocytoma reveals a novel prognostic marker. Am J Pathol 19971511153–1161. [PMC free article] [PubMed] [Google Scholar]
- 15.Mairal A, Terrier P, Chibon F.et al Loss of chromosome 13 is the most frequent genomic imbalance in malignant fibrous histiocytomas. A comparative genomic hybridization analysis of a series of 30 cases. Cancer Genet Cytogenet 1999111134–138. [DOI] [PubMed] [Google Scholar]
- 16.Idbaih A, Coindre J M, Derre J.et al Myxoid malignant fibrous histiocytoma and pleomorphic liposarcoma share very similar genomic imbalances. Lab Invest 200585176–181. [DOI] [PubMed] [Google Scholar]
- 17.Nilbert M, Rydholm A, Mitelman F.et al Characterization of the 12q13–15 amplicon in soft tissue tumors. Cancer Genet Cytogenet 19958332–36. [DOI] [PubMed] [Google Scholar]
- 18.Oliner J D, Pietenpol J A, Thiagalingam S.et al Oncoprotein MDM2 conceals the activation domain of tumour suppressor p53. Nature 1993362857–860. [DOI] [PubMed] [Google Scholar]
- 19.Stratton M R, Moss S, Warren W.et al Mutation of the p53 gene in human soft tissue sarcomas: association with abnormalities of the RB1 gene. Oncogene 199051297–1301. [PubMed] [Google Scholar]
- 20.Leach F S, Tokino T, Meltzer P.et al p53 mutation and MDM2 amplification in human soft tissue sarcomas. Cancer Res 1993532231–2234. [PubMed] [Google Scholar]
- 21.Wunder J S, Czitrom A A, Kandel R.et al Analysis of alterations in the retinoblastoma gene and tumor grade in bone and soft‐tissue sarcomas. J Natl Cancer Inst 199183194–200. [DOI] [PubMed] [Google Scholar]
- 22.Debily M A, Camarca A, Ciullo M.et al Expression and molecular characterization of alternative transcripts of the ARHGEF5/TIM oncogene specific for human breast cancer. Hum Mol Genet 200413323–334. [DOI] [PubMed] [Google Scholar]
- 23.Huang S P, Wu M S, Shun C T.et al Interleukin‐6 increases vascular endothelial growth factor and angiogenesis in gastric carcinoma. J Biomed Sci 200411517–527. [DOI] [PubMed] [Google Scholar]
- 24.Kwok W K, Ling M T, Lee T W.et al Up‐regulation of TWIST in prostate cancer and its implication as a therapeutic target. Cancer Res 2005655153–5162. [DOI] [PubMed] [Google Scholar]
- 25.Goel A, Janknecht R. Concerted activation of ETS protein ER81 by p160 coactivators, the acetyltransferase p300 and the receptor tyrosine kinase HER2/Neu. J Biol Chem 200427914909–14916. [DOI] [PubMed] [Google Scholar]