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Biomedical subjects

F Mitelman

Publications and source records attributed to F Mitelman.

At least 109 records · Page 6Linked to original sources

Cytogenetic analysis of subcutaneous angiolipoma: further evidence supporting its difference from ordinary pure lipomas: a report of the CHAMP Study Group.

Subcutaneous angiolipomas are benign soft-tissue lesions consisting of two mesenchymal elements (i.e., adipose tissue and blood vessels) and having distinct clinical features. They usually are multiple, with an obvious male predominance, and hereditary occurrence has been described. Twenty subcutaneous angiolipomas from 10 patients with typical clinical and morphologic features were reviewed. All lesions had a normal karyotype. This finding is in striking contrast with ordinary lipomas, spindle-cell and pleomorphic lipomas, lipoblastomas, and hibernomas, most of which have characteristic clonal chromosomal aberrations. The normal karyotype of subcutaneous angiolipoma as well as its distinct clinical and morphologic features suggest a different pathogenesis from pure lipomas.

Adult↗

Cytogenetic abnormalities and clonal evolution in an adult hepatoblastoma.

Hepatoblastomas usually occur in children < 3 years of age, and only occasional adult cases have been described. To date, 20 cytogenetically abnormal childhood hepatoblastomas have been reported. Karyotypic investigations have shown that most hepatoblastomas are diploid or hyperdiploid, often displaying trisomies for chromosomes 2 and 20. We have cytogenetically investigated an adult hepatoblastoma for which no previous karyotypic data exist. A hypertriploid stemline with multiple numerical and structural chromosomal aberrations, including +2 and +20, was found. In addition, the tumor displayed extensive clonal evolution with 11 subclones. Although the tumor thus displayed some chromosomal abnormalities commonly observed in childhood tumors, providing further support for the importance of these abnormalities in the development of hepatoblastoma, the level of genomic complexity seen in the present case has never been described in childhood hepatoblastomas and may suggest a different etiology or pathogenesis.

Aged↗

Poor survival in t(8;21) (q22;q22)-associated acute myeloid leukaemia with leukocytosis.

Twenty-nine consecutive cases with a t(8;21)(q22;q22) in the bone marrow (BM) karyotype were retrospectively studied concerning clinical, morphological and cytogenetic data. All had been diagnosed as acute myeloid leukaemia (AML), 27 FAB subtype M2 and two M1, comprising 5% of all cytogenetically analysed AML during 18 yr. Auer rods were the most consistent t(8;21)-associated morphological finding and were demonstrated in 92% of the reviewed BM specimens, whereas BM eosinophilia was seen in only 24%. The median age was 53 yr, and 30% of the patients were > 60 yr old. Twenty-four patients had received induction chemotherapy; 22 of these (91%) entered a complete remission (CR). The median survival time in treated patients was 18 months. Leukocytosis at diagnosis (> or = 20 x 10(9)/1) was significantly (p = 0.01) associated with shorter survival time. All four children are still in first CR after 9-80 months. Seven cases (25%) developed granulocytic sarcomas, discovered either at diagnosis (n = 4) or at first relapse (n = 3). Secondary chromosome abnormalities were found in 62% of the cases, most often loss of a sex chromosome. The presence of such secondary aberrations did not correlate with any morphological or clinical characteristics, including survival. This first Scandinavian study of AML with t(8;21) corroborates the previous findings that these AMLs are characterized by distinct morphological features, a high frequency of CR and a striking tendency to develop extramedullary leukaemic manifestations. Leukocytosis at diagnosis indicates a less favourable prognosis.

Adolescent↗

Prognostic impact of bone marrow karyotype in childhood acute lymphoblastic leukaemia: Swedish experiences 1986-91.

The prognostic value of cytogenetic classification in acute lymphoblastic leukaemia (ALL) was evaluated in Swedish children below 16 years of age (n = 372) diagnosed between 1986 and 1991. A bone marrow karyotype was obtained in 281 cases, of which 149 (53%) showed clonal abnormalities. Event-free survival (p-EFS) was 0.64-0.69 in patients with diploid and pseudodiploid karyotype. Patients with massive hyperdiploidy (> 50 chromosomes) had the best outcome (p-EFS = 0.76) and those with hypodiploidy (< 46 chromosomes) had the worst (p-EFS = 0.33). White blood cell count and age were the strongest predictors of outcome. The karyotype reached borderline significance. The diagnostic karyotype was also a predictor of outcome after relapse, with hyperdiploid patients doing better than the others. The presence of a structural chromosomal abnormality did not constitute a negative prognostic factor when intensive chemotherapy was given.

Adolescent↗

Deletion of the short arm of chromosome 3 in breast tumors.

Deletions in the short arm of chromosome 3 have long been known to be common in many tumor types, including carcinomas of the lung and kidney. Small interstitial deletions of the proximal-central region of 3p, with band 3p14 as a minimal common deleted segment, have recently been shown to occur in as many as 10% of carcinomas of the breast, often as the only chromosomal change. Seemingly identical deletions may also be found in the epithelial cells of mixed-lineage benign tumors of the breast and even in diffuse proliferative breast disease, a disorder that would not normally be accepted as neoplastic, but never in completely normal breast tissue. The cytogenetic evidence therefore indicates that the putative tumor suppressor gene deleted from 3p14 influences cellular proliferation; evidently, its loss is often not sufficient for a fully malignant phenotype to emerge. The first information about FHIT, a candidate suppressor gene recently identified in the FRA3B fragile site in 3p14 and found to be abnormal or lost in a high percentage of carcinomas of various organs, including breast, is compatible with such a general proliferation-regulating role.

Breast Neoplasms↗

BCR/ABL-negative chronic myeloid leukemia with ETV6/ABL fusion.

A BCR/ABL-negative chronic myeloid leukemia (CML) with t(12;14) (p12;q11-13) as the sole chromosomal abnormality was investigated by fluorescence in situ hybridization (FISH), which disclosed a cryptic insertion of ETV6 (previously called TEL), located at 12p12, into ABL at chromosome band 9q34. ETV6/ABL fusion was confirmed by RT-PCR, revealing that the first five exons of ETV6 were fused in frame with ABL at exon 2. Wild-type ETV6 was expressed, in accordance with the FISH results showing no deletion of the second ETV6 allele. ETV6/ABL chimeric transcripts have previously been reported in acute leukemias, but never before in CML. The present case suggests that ETV6/ABL positivity may constitute a new genetic subgroup of BCR-negative CML.

Adult↗

The FHIT and PTPRG genes are deleted in benign proliferative breast disease associated with familial breast cancer and cytogenetic rearrangements of chromosome band 3p14.

We have used nested reverse transcription-PCR (RT-PCR) and PCR on genomic DNA to search for aberrations in the FHIT and PTPRG genes, both located in chromosomal band 3p14.2, in specimens from cytogenetically analyzed benign breast lesions (three samples with atypical hyperplasia and one with fibroadenosis) from two women belonging to breast cancer families. The transcription analysis showed that the FHIT gene was either not expressed or that its expression was dramatically reduced to a level not detectable by nested RT-PCR in the samples with atypical hyperplasia. Genomic analysis of exons 3 and 5 of FHIT and exon 12 of PTPRG provided evidence that these DNA segments were homozygously deleted in the majority of the cells. These data are in line with the histopathological features and cytogenetic findings in the three samples; none contained normal parenchyma, and all had chromosomal aberrations involving band 3p14. RT-PCR analysis of the fibroadenosis specimen, which had a normal karyotype, detected the expected 856-bp fragment as well as an additional alternative transcript variant of FHIT with 1014 bp. The additional 158-bp sequence, which may add 38 amino acids to the NH2-terminal part of the previously described FHIT protein, was inserted between exons 4 and 5 and seems to be a new exon located in intron 4 of FHIT.

Acid Anhydride Hydrolases↗

Expression patterns of the human sarcoma-associated genes FUS and EWS and the genomic structure of FUS.

FUS (TLS) was first identified as the 5'-part of a fusion gene with CHOP (GADD153, DDIT3) in myxoid liposarcomas with t(12; 16)(q13; p11). Homologies were found with the EWS oncogene, which is rearranged in Ewing sarcomas and other neoplasias. The genomic structure of FUS shows extensive similarities with that of EWS, but the exon/intron structures differ in the 5' parts, and overall FUS is smaller than EWS. Exon 3 of FUS corresponds to exons 3 and 4 in EWS. FUS exons 4-6 correspond to EWS exons 5-8. Exons 7 to 15 of FUS are very similar to those in EWS, although the EWS exons are larger than the corresponding FUS exons. FUS and EWS were expressed in all tissues investigated. The transcripts were stable within the 160-min half-life experiments. No or little variation in FUS or EWS expression was seen when resting lymphocytes were activated. These observations indicate that FUS and EWS belong to the housekeeping type of genes. This view is supported by the presence of the housekeeping gene type of promoter region in both genes.

Amino Acid Sequence↗

Duplication of chromosome segment 12q15-24 is associated with atypical lipomatous tumors: a report of the CHAMP collaborative study group. CHromosomes And MorPhology.

Ordinary lipomas are cytogenetically characterized by a variety of balanced rearrangements involving chromosome segment 12ql3-15, and atypical lipomatous tumors (ALT) by supernumerary ring chromosomes or giant markers known to contain amplified 12q sequences. In a series of 228 cytogenetically analyzed and histopathologically reexamined ordinary lipomas and ALT, 10 tumors showed unbalanced chromosome-12 aberrations. All 4 tumors with loss of segments from 12q were classified as ordinary lipomas, whereas 5 of the 6 tumors showing gain of 12q material were diagnosed as ALT. One or three extra copies of 12q15-q24 were present in all 5 ALT. We conclude that duplication of 12q sequences may be a sufficient level of amplification for development of the microscopic appearance that characterizes ALT.

Chromosome Aberrations↗

Correlation between karyotypic pattern and clincopathologic features in 125 breast cancer cases.

A correlation analysis was performed on 125 cytogenetically characterized breast cancer cases to assess the relationship between the tumor karyotype and clinicopathologic features. The carcinomas of young women had a higher modal chromosome number than those of older women. The number of chromosomal aberrations and modal chromosome number were also found to correlate with the histologic type, grade and mitotic activity of the tumor. Whereas all lobular carcinomas were karyotypically normal or near-diploid, more than 3 aberrations and sometimes near-triploid or near-tetraploid karyotypes were common findings in ductal carcinomas, especially in grade-III tumors and in tumors showing high mitotic activity in vivo. Karyotypes with cytogenetically unregulated clones and unbalanced structural chromosomal rearrangements were more frequent in infiltrating than in in situ carcinomas but, at least as far as the second of these 2 characteristics is concerned, especially in infiltrating carcinomas that also had an in situ component. The presence of cytogenetic polyclonality correlated with tumor grade. Although recurrent chromosome aberrations were significantly more common in ductal than in lobular carcinomas, none of these breast cancer-associated anomalies seemed to be specific for any particular clinicopathologic parameter. The associations between modal chromosome number and mitotic activity and between cytogenetic polyclonality and tumor grade were found to be statistically significant in multivariate models. No correlations was seen between the karyotypic findings and tumor size or the presence of axillary-lymph-node metastases.

Adult↗

Fusion of the EWS and CHOP genes in myxoid liposarcoma.

The translocation t(12;16)(q13;p11), which cytogenetically characterizes myxoid liposarcomas (MLS), results in a fusion of the CHOP gene in 12q13 and the FUS gene in 16p11, creating a chimeric FUS/CHOP gene. We have identified two cases of MLS with translocations giving rise to recombination between 12q13 and 22q12. The result was a fusion of the N-terminal part of the EWS gene in 22q12, involved in a number of mesenchymal tumor types, with the CHOP gene and the creation of an EWS/CHOP chimeric gene. The presence of the EWS/CHOP chimeric gene in MLS shows that (i) the N-terminal part of FUS may be replaced by the N-terminal part of EWS in a CHOP fusion oncoprotein (ii) the two N-terminal parts, when fused to certain transcription factors, have a common or very similar oncogenic potential and (iii) the tumorigenic process in MLS and the morphogenetically distinctly different EWS-associated tumor types may be related.

Amino Acid Sequence↗

Molecular characterization of 12p abnormalities in hematologic malignancies: deletion of KIP1, rearrangement of TEL, and amplification of CCND2.

Twenty patients with hematologic malignancies with 12p abnormalities were investigated by fluorescence in situ hybridization (FISH) using probes mapped to specific regions in 12p. The initial analysis using the YAC 964c10 (D12S736) revealed that all four cases with cytogenetically identified del(12p) had lost one copy of this YAC and that submicroscopic deletions had occurred in 10 of the 16 neoplasms with other 12p abnormalities, ie, translocations, additions, and insertions. The deletions were partially mapped with cosmids localized to subregions of 12p. One copy of the gene for p27kip1 (KIP1), involved in cell cycle entrance, was found to be lost in all cases in which deletions could be detected by other probes and in one case with a translocation as the only detectable change. This implicates KIP1 as a possible tumor suppressor gene affected by del(12p). Four translocations with no apparent concomitant deletions were detected. All four breakpoints resulted in a split D12S736 signal. In two of these cases, we showed that TEL was disrupted as a result of a t(5;12)(q32-33;p12) and a t(12;22)(p12;q12), respectively. Two lymphoid neoplasm--one non-Hodgkin's lymphoma and one Burkitt's lymphoma--with 12p amplifications were detected. In both cases cyclin D2 (CCND2) was within the amplified region. Thus, cytogenetic abnormalities of 12p in hematologic malignancies result in at least three different molecular changes: deletions of KIP1, amplifications of CCND2, and structural rearrangements of TEL.

Adult↗

Cytogenetic studies on fine-needle aspiration samples from osteosarcoma and Ewing's sarcoma.

The preoperative multidrug chemotherapy of osteosarcoma and Ewing's sarcoma patients requires a reliable diagnosis. There are several advantages with obtaining the diagnosis by fine-needle aspiration (FNA) and cytologic examination. Although cytologic criteria have been defined, adjunctive methods such as cytogenetic analysis are valuable to support the diagnosis. We have cytogenetically analyzed FNAs from 18 primary bone sarcomas (six osteosarcomas and 12 Ewing's sarcomas). Two of the osteosarcomas showed abnormal, complex karyotypes seen in most highly-malignant osteosarcomas. Seven Ewing's sarcoma aspirates displayed abnormal karyotypes; five of these had the characteristic 11;22 translocation, and in one of these cases molecular genetic analysis revealed the hybrid EWS/FLI1 transcript. Since only two of six osteosarcomas showed clonal changes, chromosomal analysis of FNAs from suspected osteosarcoma seems to be of limited value, but may in some cases support the diagnosis of high-grade malignancy. In Ewing's sarcomas, however, the finding of an 11;22 translocation was valuable and strongly supported the cytologic diagnosis. As shown in one case, the material obtained by FNA is sufficient for cytologic, cytogenetic, and molecular genetic analysis.

Adolescent↗

Clonal chromosome abnormalities in two chemodectomas.

Short-term cultures from two histologically benign chemodectomas, one from the carotid body and one from the vagal nerve, were analyzed cytogenetically. The former had a small abnormal clone with the karyotype 46,XX,t(3;19)(q21;q13),t(12;15) (p13;q12-14), whereas the majority of the cells from the latter tumor displayed two related abnormal clones: 46,XY,i(I)(q10)/ 46,iderm,add(2)(q37). The findings add to the evidence that chemodectomas are heterogeneous neoplasms and suggest that the heterogeneity may possibly be associated with the site of origin.

Carotid Body Tumor↗

Different cytogenetic patterns in skeletal breast cancer metastases.

Short-term cultures of breast cancer metastases to bone from two patients were analyzed cytogenetically. One metastasis had a complex hypotriploid karyotype with numerous marker chromosomes, whereas the other had simple karyotypic changes in three unrelated clones, 46,XX,t(4;11 )(p14;p 13)/45,XX,- 19/46,XX,del(3)(p 13p23), suggesting that the metastasis had originated from a simultaneous invasion of multiple cells from the primary tumor. The metastasis with complex chromosomal aberrations developed quickly as part of a clinically aggressive disease, whereas that with simple changes developed more than 20 years after the initial breast cancer diagnosis. Our findings therefore indicate that the tumor karyotype may play a role in determining the clinical course in patients with breast cancer.

Bone Neoplasms↗

19p+ marker chromosome correlates with relapse in malignant fibrous histiocytoma.

In this study, we examined the relationship of 19p13 aberrations, usually leading to addition of unknown material (19p+), and ring chromosomes to clinical outcome in patients with malignant fibrous histiocytoma (MFH). Analysis of 69 MFHs revealed 19 tumors with 19p+ and 24 tumors with ring chromosomes. After a median follow-up period of 36 months, 24 patients developed metastases, and 27 patients developed local recurrences. Ten patients had both local recurrences and metastases. Local recurrence was more common in association with 19p+ than without. Metastasis was more common with 19p+ tumors in high-risk patients (tumor size > 5 cm and grade III-IV; n = 48) than those without 19p+. There was a trend suggesting fewer relapses after tumors with ring chromosomes. 19p+ may be an independent marker of unfavorable outcome in MFH.

Adult↗

Primary vs. secondary neoplasia-associated chromosomal abnormalities--balanced rearrangements vs. genomic imbalances?

Two quite distinct neoplasia-associated karyotypic patterns are emerging. One is characterized by simple and disease-specific abnormalities, and the other is characterized by multiple and nonspecific aberrations. The former pattern is typical of most leukemias and lymphomas and of some mesenchymal tumors, but it is rare in epithelial neoplasms. The latter pattern is found in most epithelial tumor types, in several mesenchymal neoplasms, but in only a few hematologic malignancies. Primary chromosome aberrations, which are believed to be essential in establishing the neoplasm, and secondary changes, which are considered to be important in tumor progression, may be distinguished in the tumors characterized by simple and disease-specific abnormalities. Here, we propose that these aberrations are genetically and hence, most likely, functionally distinct. Primary abnormalities lead to specific gene rearrangements, whereas secondary chromosomal changes result in large-scale genomic imbalances. According to this hypothesis, there are no unbalanced primary aberrations, only secondary imbalances masquerading as primary. This proposition has a number of conceptual ramifications. First, the genetic mechanisms underlying tumor initiation and progression would seem to be totally different. Second, the elucidation of the molecular consequences of the secondary aberrations will be an arduous task, even if one were to adhere to the view that cytogenetically identified genomic imbalances may be reduced to simple gains or losses of single oncogenes or tumor suppressor genes. Third, the cytogenetic diagnosis of neoplasms will have to take into account that an unbalanced "primary" abnormality is secondary to a submicroscopic, truly primary change of major diagnostic and prognostic importance.

Chromosome Aberrations↗