Biologic characteristics of four Ewing's sarcomas

Characterization of 11 human sarcoma cell strains: evaluation of cytogenetics, tumorigenicity, metastasis, and production of angiogenic factors

BACKGROUND

Human sarcomas have a propensity for aggressive local invasion and early pulmonary metastasis. Frequently, deaths are due to uncontrolled pulmonary metastases. The purpose of the current study was to evaluate cytogenetics, tumorigenicity, metastatic potential, and production of angiogenic factors in human sarcoma cell strains. A secondary purpose was to establish low passage cell strains for studying new therapeutic approaches.

METHODS

The authors established 11 cell strains from human sarcoma surgical specimens and characterized their in vitro tumor properties, including growth in soft agar, expression of angiogenic growth factors (vascular endothelial growth factor [VEGF] and basic-fibroblast growth factor [bFGF]), and cytogenetics.

RESULTS

All of the cell strains remained diploid. All exhibited the ability to grow in soft agar and expressed both VEGF as well as bFGF. In addition, 6 of the 11 established sarcoma cell strains were tumorigenic, 5 of which spontaneously metastasized to the lungs in nude mice. Four of the five cell strains that yielded lung metastases were derived from lung metastases in patients.

CONCLUSIONS

The 11 cell strains, which were derived from diverse sarcoma histologies, will provide a model for studying not only metastatic progression but also the in vitro and in vivo efficacy of new therapeutic modalities for human sarcomas.

Cytogenetic characterization of Ewing tumors using fine needle aspiration samples. a 10-year experience and review of the literature

Chromosomal analysis was performed in fine needle aspiration samples of 98 primary Ewing tumors (ETs) prior to treatment. Among the 58 (59.18%) successful cultures, t(11;22)(q24;q12) was observed in 87.9% and 6.8% had abnormalities other than t(11;22), viz., del(22)(q12), der(16)t(1;16)(q12;q11), and variant t(8;22)(q24;q12). Involvement of breakpoints 1q21, 1q22, 3p14, 16q22, and 17p13 was also observed. Numerical abnormalities such as trisomies 8 and 12 were found in 29.3% and 20.6% and trisomy 18 in 17.2%. An attempt was made to evaluate the role of these additional changes in the process of tumor development, metastasis, and progression of the disease. This is the largest cytogenetic study on ET from a single center using a simple and reliable technique of fine-needle aspiration culture. The literature on cytogenetics of ET is reviewed.

Soft tissue sarcomas of infancy

Malignancy occurring during the neonatal period (defined as the first 28 days of life) is over 3 times the incidence of other pediatric age groups. Of all neoplasia occurring in infants, benign and malignant, 25% are soft tissue tumors. Differentiating the benign lesions from the 15% that are malignant can be difficult. This article discusses the epidemiology, differential diagnosis, evaluation, and treatment of infants with soft tissue sarcomas. Fibrosarcoma and rhabdomyosarcoma are also discussed at length. The authors review other rare tumors as well. The impact on diagnosis of molecular techniques is included when appropriate. A multidisciplinary team approach for treatment of these infants is recommended.

Epidemiology of osteosarcoma and Ewing's sarcoma in childhood: a study of 305 cases by the Children's Cancer Group

BACKGROUND

The Children's Cancer Group conducted a case-control study to determine the role of a broad range of environmental and familial factors in the etiology of Ewing's sarcoma and osteosarcoma in children. These factors included radiation exposure and, for children with osteosarcoma, parental exposure to beryllium.

METHODS

The parents of 152 children with osteosarcoma and 153 children with Ewing's sarcoma were interviewed by telephone. Controls were obtained by random digit dialing and were matched to cases by age and race.

RESULTS

Female osteosarcoma patients had earlier onset of breast development (age 11.4 vs. 11.8 years, P=0.03) and menarche (age 12.1 vs. 12.5 years, P=0.002) but no significant differences in growth, whereas male osteosarcoma patients were similar in age at the onset of secondary sexual characteristics but reported significantly less weight gain during their growth spurt (6.6 vs. 11.7 kg, P=0.003). For children with Ewing's sarcoma, the growth spurt began earlier (age 12.1 vs. 12.7 years, P=0.12) and resulted in less weight and height gain (5.2 vs. 9.7 kg, P=0.002, and 10.2 vs. 12.7 cm, P=0.02, respectively) for males, but no differences were observed among females. For factors not related to growth and development (including a wide range of occupational, medical, and household exposures), there was little evidence of an etiologic role with respect to either tumor type.

CONCLUSIONS

Differences between cases and controls with respect to growth and development showed no consistent pattern. This study did not identify any important risk factors for either type of childhood bone tumor.

Additional chromosome 1q aberrations and der(16)t(1;16), correlation to the phenotypic expression and clinical behavior of the Ewing family of tumors

The cytogenetic hallmark of the Ewing family of tumors is t(11,22)(q24;q12) in its simple, complex or variant forms and/or its molecular equivalent EWS/FLI, EWS/ERG rearrangement. Additional secondary consistent chromosomal aberrations include the der(16)t(1;16) and frequently, other chromosome 1q abnormalities leading to 1q overdosage. We studied whether these secondary cytogenetic changes are correlated to clinical features and phenotypic expression which may have a prognostic impact. Successful cytogenetic evaluation was performed in eight patients with a Ewing family tumor. In four of these, in addition to the primary aberration, chromosome 1q overdosage (including two with der (16)t(1;16)) was noted. Out of these four patients, two had metastatic disease at the time of evaluation, while in the other four, disease was localized. Morphologically, the tumors with the additional 1q aberration, revealed the pPNET subtype more frequently than the typical Ewing. They also expressed a higher degree of neural differentiation by neural marker immunocytochemistry, in comparison to tumors without the 1q aberration. Determination of the prognostic significance of this finding requires a longer follow-up with a larger group of patients.

In vitro proliferative advantage of bone marrow cells with tetrasomy 8 in Ewing sarcoma

We describe a case of a 14.5-year-old boy with a clinically aggressive pelvic Ewing sarcoma. The tumor cells showed the presence of a typical t(11;22)(q24;q12) aberration and gains of chromosomes 8, 10, 14, and 21. To determine the size of the trisomy and tetrasomy 8 clones an interphase analysis by fluorescence in situ hybridization with a centromere-specific chromosome 8 probe was performed. Significant quantitative differences between metaphase and interphase data were obtained. It was shown that culturing of bone marrow cells leads to enrichment of tetrasomy 8 population that may be explained by the proliferative advantage of the tetrasomy 8 cells.

Metastatic extraosseous Ewing tumor. Association of the additional translocation der(16)t(1;16) with the variant EWS/ERG rearrangement in a case of cytogenetically inconspicuous chromosome 22

In Ewing sarcoma and related tumors, recently referred to as the Ewing tumors (ET), t(11;22)(q24q12) and its molecular genetic equivalent, the EWS/FLI-1 rearrangement, characterize approximately 85% of cases, while variant aberrations are rare. A second nonrandom aberration in ET is the unbalanced t(1;16) accompanying the t(11;22) in roughly 17% of cases. We present a 17-year-old man with estraosseous ET and multiple metastases, in whom the only cytogenetically detectable chromosomal aberration was der (16)t(1;16)(q12;q11.2). This finding was confirmed by fluorescence in situ hybridization (FISH). Using the RT-PCR technique, a variant EWS/ERG fusion transcript was noted, resulting from a t(21;22) chromosomal rearrangement which recently demonstrated in roughly 10% of ET. However, data on possible biologic differences in EWS/FLI-1 versus EWS/ERG expressing ET are as yet unavailable. This is the first reported combination of t(1;16) with the EWS/ERG rearrangement. A possible significance of this finding for Ewing tumor progression is discussed.

Atypical cytogenic aberrations in two childhood peripheral primitive neuroectodermal tumors

Atypical cytogenetic abnormalities were detected in peripheral primitive neuroectodermal tumors (PPNET) of the extremity in two children. One had an osseous tumor with a balanced reciprocal translocation, t(5;9)(q22;q32), and had a complete response to therapy. The other had a non-osseous tumor with an interstitial deletion, del(18)(q12.2q21.2), was resistant to combination therapy, and at autopsy had evidence of possible clonal evolution with the karyotype 46,XX der(8)t(8;8)(p11.2;q13), inv(16)(p13.2q12),del(18)(q12.2q21.2). Neither tumor demonstrated the t(11;22)(q24;q12) typically found in Ewing's sarcoma and PPNET, suggesting heterogeneity of the cytogenetic aberrations seen in this rare childhood malignancy.

Translocation (1;16) identified by chromosome painting, and PRimed IN Situ-labeling (PRINS). Report of two cases and review of the cytogenetic literature

We used the molecular cytogenetic in situ techniques chromosome painting and PRimed IN Situ labeling (PRINS) to elaborate the cytogenetic observations in two cases of the rare aberration der(16)t(1;16), which occurs in a wide variation of hematologic and nonhematologic malignancies [1-3]. Review of the literature showed that, in contrast to the chromosome 1 breakpoint, the breakpoint on chromosome 16 is associated with diagnosis as well as patient age.

Cytogenetic and pathologic aspects of Ewing's sarcoma and neuroectodermal tumors

Diagnostic classification of poorly differentiated, round cell, primitive neuroectodermal neoplasms, including Ewing's sarcoma, peripheral neuroepithelioma, Askin's tumor, and esthesioneuroblastoma, is challenging to the surgical pathologist using conventional histopathologic approaches because of very similar and overlapping morphologic and cytologic features. Furthermore, distinguishing these neoplasms from neuroblastoma, embryonal rhabdomyosarcoma, small cell osteogenic sarcoma, and non-Hodgkin's lymphoma can be difficult. This paper describes and reviews the cytogenetic and molecular genetic changes in these tumors and demonstrates how the ability to detect these changes has enabled a greater understanding of the histogenesis, classification, diagnosis, and prognosis of these neoplasms.

Cytogenetics and molecular biology of small round-cell tumors and related neoplasms. Current status

Recent years have witnessed considerable advances in cytogenetics and molecular biology of small round-cell tumors. These advances are summarized and discussed in this article.

Soft tissue Ewing's sarcoma. Characterization in established cultures and xenografts with evidence of a neuroectodermic phenotype

This study characterizes the histogenesis of soft tissue Ewing's sarcoma (StEs) based upon an analysis of three tumors. Long-term cultured cell lines and nude mice xenografts were established from original neoplasms or from their metastases. Histologically they revealed a small round cell pattern without signs of differentiation. Several ultrastructural features of neural type were found; the same were also seen on culture cell lines. Moreover, immunohistochemical study for neural markers revealed the presence of HNK-1, NSE, LIRC-LON 36, S-100 protein, glial fibrillary acidic protein, neurofilaments (70 kilodaltons), and chromogranin; some of these markers were present only in the transplants. Cytokeratin was also seen. The translocation t(11;22)(q24;q12) was found in all three neoplasms together with other chromosomal abnormalities. N-myc RNA gave negative results whereas c-myc RNA was expressed. Therefore it may be postulated that StEs displays neuroectodermal features somewhat similar to those seen in peripheral neuroepithelioma as well as in atypical Ewing's sarcoma of bone.

11q23 abnormalities in children with acute nonlymphocytic leukemia (M4-M5). Association with previous chemotherapy

Cytogenetic studies of 12 patients aged less than 14 years with acute nonlymphoblastic leukemia (ANLL) (M4-M5) showed structural abnormalities on chromosome 11 at band q23-q24 in five cases (41.8%). Four of these 12 patients had ANLL (M4-M5) after treatment with cytostatics for non-Hodgkin lymphoma in one case and for an acute lymphoblastic leukemia (ALL) in the other three. Three of these four cases had 11q23 abnormalities [one [one 46,XY,t(11;17)(q23;25); another 47,XY,+8,-15,del(11)(q23),+der(15)t(15;?)(p11;?); the third 47,XX,+8,t(3;17) (p11;q25),t(4;11)(q21;q23)] and one had a normal karyotype on being diagnosed ANLL (M4-M5). The notable increase of ANLL (M4-M5) in our patients who had received cytostatics as treatment for a previous neoplasia makes evaluation of our results timely in comparison with those of other groups who use these therapeutic protocols.

Cytogenetic subtype involving chromosome 13 in lipoma. Report of three cases

We report three lipomas with rearrangements of chromosome 13. The karyotype of the tumors studied were 45,XX,-8,+der(8)t(8;13)(q22;q12),del(10)(p12),-13; 46,XY,del(13)(q12q22), and 46,XY,t(11;12)(q23;q13),del(13)(q12q22), respectively, revealing common involvement of band 13q12 in the rearrangement. Three other lipomas with aberrations of bands 13q12-q13 have been reported, suggesting that such tumors with abnormalities of chromosome 13 could represent a subgroup of lipoma in addition to those already reported with abnormalities of chromosomes 12q and 6p. The rearrangements of #13 in all these cases also involved loss of the band 13q14 to which the antioncogene associated with retinoblastoma and osteosarcoma is localized. Detailed clinical, histopathologic, and molecular studies should help to further characterize the various cytogenetically defined subgroups of lipoma.

Extraskeletal Ewing's tumor with translocation t(11;22) in a patient with Down syndrome

A case of a small cell malignant tumor that occurred in the soft tissues of a 16-year-old boy with Down syndrome (47,XY,+21) is reported. The histologic and histochemical patterns were consistent with an extraskeletal Ewing's sarcoma (ES). The cytogenetic analysis of the tumor cells showed a t(11;22)(q24;q21), tetrasomy of chromosome 21, and trisomy of chromosome 14. The observation of a t(11;22) in an ES gives credit to the morphologic evidence in favor of the common (probably neuroectodermal) origin of the skeletal and extraskeletal forms of Ewing's sarcoma (ES). The possible pathogenetic significance of the constitutional trisomy of chromosome 21 in determining the occurrence of this tumor is discussed.

Two new cases of primary peripheral neuroepithelioma of soft tissue with translocation t(11;22)(q24;q12)

A direct cytogenetic analysis was performed on tumor samples obtained from two patients with clinical and histopathologic diagnosis of primary peripheral neuroepithelioma. Both tumors presented the translocation t(11;22)(q24;q12). These results confirm those previously obtained by other authors and suggest a common histogenetic origin for this tumor with Ewing's sarcoma and Askin's tumor, in which the same translocation has been described.

Chromosomes in Ewing's sarcoma. I. An evaluation of 85 cases of remarkable consistency of t(11;22)(q24;q12)

Since our initial reports on chromosomal studies in eight Ewing's sarcomas (ES), we have carried out similar investigations on 23 additional ES specimens following short-term culture of tumor cells (16 cases), and established in vitro cell lines (three cases) and on xenografted tumors in nude mice (four cases). We demonstrated the presence of the reciprocal t(11;22)(q24;q12) in every case except one that exhibited a complex t(11;22;14)(q24;q12;q11). On the basis of results from these additional 23 cases, we confirm the consistency of the t(11;22)(q24;q12) in ES. Moreover, we reviewed 54 ES cases reported by other investigators; when added to our 31 cases, this brings the total number to 85 unrelated cases of ES available for an evaluation of the frequency of involvement of bands 11q24 and 22q12 in translocations in ES. The standard t(11;22)(q24;q12) proved to be a remarkably consistent event, present in 83% of the cases. Five percent of the cases exhibited complex translocations involving a third chromosome in addition to chromosomes #11 and #22. In 4% of the cases variant translocations involved 22q12 but with a chromosome(s) other than #11. The breakpoint on chromosome 22q12 appears to be the most consistently observed event in 92% of the cases, whereas, the breakpoint at chromosome 11q24 was observed in 88% of the cases.

Chromosomes in Ewing's sarcoma. II. Nonrandom additional changes, trisomy 8 and der(16)t(1;16)

Chromosomal data from 82 informative, unrelated Ewing's sarcoma (ES) specimens (including 20 personal specimens) were reviewed for secondary changes additional to the t(11;22)(q24;q12). Additional numerical and/or structural changes were found in 75 specimens. Trisomy 8 was observed consistently in half of the 43 cases selected for analysis of numerical changes. A nonrandom der(16) was observed as a result of an unbalanced t(1;16) in 18% of the 82 analyzed for structural changes. Consistent involvement of chromosome #16 in rearrangements with chromosome #1 may be an additional chromosome change specifically associated with ES.

Trisomy of the long arm of chromosome 1 in patients with hematologic malignancies and solid tumors: report of six cases

Complete or partial trisomy of the long arm of chromosome #1 was observed in six patients with malignant disorders. Four patients suffered from hematologic diseases (two cases of refractory anemia with excess of blasts and one case each of acute myeloblastic leukemia and Burkitt lymphoma), and two had solid tumors (retinoblastoma and Ewing's sarcoma). In all cases the excess material included the distal part of chromosome #1. Such material was translocated to chromosomes #16 (three patients), #3, #9, and Y (one patient each), and this was accompanied by additional cytogenetic changes in five of the six patients. The present and other previously published observations support the hypothesis of the localization of genes responsible for malignant growth in the distal segments of chromosome #1.

Beta-adrenergic agonist- and prostaglandin-mediated regulation of cAMP levels in Ewing's sarcoma cells in culture

This is the first report demonstrating hormonal control of cAMP levels in Ewing's sarcoma cells. Two classes of hormones, beta-adrenergic agonists and prostaglandins stimulate cAMP production in cultured Ewing's sarcoma cells. The efficacy order for beta-adrenergic agonists is (-)-isoprenaline greater than or equal to (-)-noradrenaline greater than or equal to (-)-adrenaline much greater than (-)-phenylephrine. The stimulatory effect of (-)-noradrenaline is antagonized by beta 1-selective metoprolol and also by beta 2-selective ICI 118,551. The efficacy order for prostaglandins (PG) is PGE1 greater than PGI2 greater than PGE2 much greater than PGF2 alpha; 6-keto PGF1 alpha and PGD2 do not influence cAMP levels in Ewing's sarcoma cells. Cultures pretreated with PGE2 are less responsive to a second challenge with PGE2 but their response to (-)-isoprenaline is unimpaired. Similarly, pretreatment with (-)-isoprenaline induces homologous desensitization to (-)-isoprenaline and has no effect on the PGE2-stimulated increase in cAMP. We conclude that these cells provide an ideal model for the study of the initial steps of beta-adrenergic and prostaglandin action in Ewing's sarcoma.

Isochromosome 11q in a case of Ewing's sarcoma

A low passage Ewing's sarcoma cell line established from a metastatic lesion was cytogenetically analyzed. The modal karyotype was 44,X, -8,i(11q), -15, +12. Other cells had random chromosome aneuploidy superimposed on this karyotype. No cell had a structural rearrangement involving 11q24 or 22q12 as described in other patients with Ewing's sarcoma, but all cells had an isochromosome 11q.

Human chromosome 22

The acrocentric chromosome 22, one of the shortest human chromosomes, carries about 52 000 kb of DNA. The short arm is made up essentially of heterochromatin and, as in other acrocentric chromosomes, it contains ribosomal RNA genes. Ten identified genes have been assigned to the long arm, of which four have already been cloned and documented (the cluster of lambda immunoglobulin genes, myoglobin, the proto-oncogene c-sis, bcr). In addition, about 10 anonymous DNA segments have been cloned from chromosome 22 specific DNA libraries. About a dozen diseases, including at least four different malignancies, are related to an inherited or acquired pathology of chromosome 22. They have been characterised at the phenotypic or chromosome level or both. In chronic myelogenous leukaemia, with the Ph1 chromosome, and Burkitt's lymphoma, with the t(8;22) variant translocation, the molecular pathology is being studied at the DNA level, bridging for the first time the gap between cytogenetics and molecular genetics.

Chromosomal analysis in Ewing sarcoma

Two cases of Ewing sarcoma were karyotyped by using a fluorodeoxyuridine synchronisation procedure on short term cultures of fresh tumour material. This procedure enables rapid cytogenetic analysis of such material. Both showed relatively simple karyotypes, 48,XX, +2, +7,t(11;22)(q24;q12), ?dup(12)(q21----q24) and 47,XX,i(1q),t(11;22)(q24;q12). These results further support this translocation between chromosomes 11 and 22 as a specific marker for Ewing sarcoma. Cytogenetic studies in such cases are an important adjunct to histological studies and in some cases may contribute to the resolution of the diagnosis.