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Biomedical subjects

B de Jong

Publications and source records attributed to B de Jong.

At least 73 records · Page 4Linked to original sources
PubMed1993

Cytogenetic abnormalities and clinical stage in testicular nonseminomatous germ cell tumors.

To study the impact of chromosomal abnormalities on the clinical behavior of testicular nonseminomatous germ cell tumors (TNSGCTs), we compared the chromosomal constitution of primary tumors of patients who initially presented and remained without metastases to those with metastatic disease. Furthermore, the chromosomal pattern of primary TNSGCTs was compared to ploidy and the clinicopathologic risk factors histology and small-vessel invasion. The modal chromosome number and the ploidy were in agreement. No correlation was found between the modal chromosome number and histology, presence of vascular invasion, or clinical stage. No correlation was found between structural chromosome abnormalities, like the number of copies of the i(12p) chromosome, and clinical stage. No obvious differences were found in chromosomal constitution of metastatic and non-metastatic tumors. The results of the present study suggest that in TNSGCTs differences in clinical behavior are not associated with gross chromosomal differences.

Adult↗
PubMed1993

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.

Carcinoma, Renal Cell↗
PubMed1993

Significance of aneuploid stemlines in testicular nonseminomatous germ cell tumors.

BACKGROUND: Hyperpentaploidy in testicular nonseminomatous germ cell tumors (TNSGCT) has been associated with progression of disease of patients who initially had TNSGCT in Stage I. METHODS: The authors used flow cytometry to investigate the relationship between ploidy and the clinical behavior in TNSGCT, focusing on hypertetraploid values (DNA index, > 2.00). RESULTS: Patients with TNSGCT containing an aneuploid stemline with a hypertetraploid value more often had higher clinical stage of disease and a higher chance of relapse in advanced stages. The presence of multiple aneuploid stemlines in the tumors was found more frequently in patients who had higher clinical stage disease. CONCLUSIONS: The results suggest that the presence of highly aneuploid or multiple aneuploid stemlines in TNSGCT are associated with a clinically more malignant behavior.

Adolescent↗
PubMed1993

Cytogenetic findings in eleven gastric carcinomas.

We describe the results of the cytogenetic study of 10 primary adenocarcinomas of the stomach and one lymph node metastasis of a gastric adenocarcinoma after direct harvesting or short-term in vitro culture. All cases showed a variable number of numerical and/or structural clonal cytogenetic aberrations. Polysomy of chromosomes 2 and 20 were the most common numerical abnormalities. Rearrangements of chromosomes 1, 3, 7, and 13 were each observed in more than half the cases. Chromosomes 3 and 13 were the chromosomes more often exhibiting structural cytogenetic aberrations. In five tumors, rearrangements of chromosome 6 resulting in partial deletion of 6q were noted (common deleted region 6q21-22-->qter). The recurrent markers observed in our series were an i(8q) and an i(17q) in three and two cases, respectively. Double minutes (dmin) or homogeneously staining regions (hsr) were evident in three tumors. Contrary to the recent claim that structural abnormalities affecting 11p13-p15 were specifically involved in gastric cancer, we detected rearrangements of this region in only two cases.

Adenocarcinoma↗
PubMed1993

Loss of heterozygosity at the short arm of chromosome 3 in renal-cell cancer correlates with the cytological tumour type.

A majority of renal-cell tumours retain heterozygosity at the short arm of chromosome 3. To investigate possible histopathological differences between tumours with and without such losses, we compared loss of heterozygosity data from 51 tumours with I histological and 2 different cytological classifications of renal-cell tumour. Using the cytological classification of Thoenes et al., we only found tumours with loss of heterozygosity in these authors' clear-cell category. Possibly, only these tumours arise by a mechanism of double loss of a tumour-suppressor gene on 3p, non-clear-cell renal tumours having a different genetic background. Alternatively, deletions may occur in all subtypes, in which case those subtypes in which no LOH is found may also contain deletions too small to be detected with the set of 3p probes we used. A cytogenetic analysis was carried out on 30 of the tumours. Results of molecular and microscopic cytogenetic analyses did not seem to be in agreement in 12 cases. In 6 of these we found allelic losses in tumours showing morphologically normal copies of chromosome 3. Mitotic recombination or loss of one chromosome 3 homologue followed by duplication of the remaining homologue is a likely explanation. The other 6 cases showed microscopic abnormalities of chromosome 3 which were not reflected, or only partly reflected, as allelic losses. These discrepancies are caused either by the limitations of microscopic analysis in exactly determining a breakpoint or tracing a translocated part of a chromosome, or by the failure of molecular analysis to demonstrate LOH if this occurs in only a minority of cells.

Carcinoma, Renal Cell↗
PubMed1993

Uniparental origin of i(12p) in human germ cell tumors.

We present molecular data to demonstrate that the isochromosome 12p, specific for human germ cell tumors (GCTs), is of uniparental origin. Eight GCT-derived cell lines, containing one or more copies of i(12p) and/or other 12p anomalies, were analyzed with different 12p-derived polymorphic markers. The results from Ma-90, a near-diploid cell line with only one i(12p) in addition to two copies of a normal chromosome 12, clearly show an allelic 12p ratio of approximately 3:1, indicating that both 12p arms are of identical parental origin. These results were further substantiated by data obtained from the other i(12p)-positive GCT-derived cell lines. Therefore, we conclude that the i(12p) in GCTs constitutes a genuine isochromosome with genetically identical arms. The isochromosome most likely originates from a misdivision of the centromere rather than from a translocation or a non-sister chromatid exchange as proposed by others. We also found that supernumerary 12p copies, as observed in i(12p)-negative GCTs, are of uniparental origin. These observations seem to point to an important role for certain 12p-derived sequences in the development of human GCTs.

Chromosome Aberrations↗
PubMed1993

Interphase cytogenetics of carcinoma in situ of the testis. Numeric analysis of the chromosomes 1, 12 and 15.

Carcinoma in situ of the testis is the precursor of seminomas and nonseminomatous germ cell tumors of the adult testis. It is a frequent finding in the testicular parenchyma adjacent to seminoma and nonseminoma. Thus far no differences have been demonstrated between carcinoma in situ adjacent to seminoma and nonseminoma; morphology, immunohistochemistry and ploidy are similar. Using in situ hybridisation of interphase nuclei, we demonstrate that the chromosomal constitution of carcinoma in situ adjacent to seminoma and nonseminoma is different. In particular, it appears that the number of copies of chromosome 15 is lower in carcinoma in situ adjacent to nonseminoma than in carcinoma in situ adjacent to seminoma, which is also true for the adjacent seminoma and nonseminoma.

Alkaline Phosphatase↗
PubMed1993

Molecular cytogenetics of human germ cell tumours: i(12p) and related chromosomal anomalies.

Human testicular germ cell tumours (TGCTs) comprise a heterogeneous group of solid neoplasms. These tumours are characterized by a highly specific chromosomal anomaly, i.e. an isochromosome of the short arm of chromosome 12. At present, this i(12p) chromosome has been observed in about 80% of TGCTs. Also in dysgerminomas of the ovary and in some extragonadal germ cell tumours i(12p) has been observed. In the remaining so-called i(12p)-negative tumours other cytogenetic abnormalities can be found. In addition, TGCTs are usually highly aneuploid. The exact nature and role of these different anomalies in tumour development are as yet undefined. Here we present a molecular cytogenetic analysis of a diverse group of gonadal and extragonadal germ cell tumours. Our results indicate that all tumours examined exhibit anomalies involving 12p [i(12p) and/or others], resulting in a distinct overrepresentation of short arm sequences. Thus, we argue that the occurrence of 12p abnormalities may be a characteristic of both i(12p)-positive and -negative TGCTs and that these abnormalities may, through similar mechanisms, contribute to the process of TGCT development. This notion is substantiated by our finding that in all cases the supernumerary 12p sequences are of uniparental origin.

Animals↗
PubMed1993

Sublocalization of the synovial sarcoma-associated t(X;18) chromosomal breakpoint in Xp11.2 using cosmid cloning and fluorescence in situ hybridization.

In a previous study we localized the synovial sarcoma-associated t(X;18)(p11;q11) breakpoint within the ornithine aminotransferase-like 1 (OATL1) cluster on the X chromosome. This localization was delineated from both somatic cell hybrid and fluorescence in situ hybridization (FISH) analysis of patient material, using OAT-specific cDNA and YAC probes. Simultaneously, Knight et al. (1992, Mol. Hum. Genet, in press) mapped this same breakpoint in their patient material adjacent to the more proximal OATL2 region on the X chromosome. Here we report the analysis of two additional tumors and demonstrate that again in these cases the chromosomal break occurs within the OATL1 cluster. In order to further specify the breakpoint, we subcloned the OATL1 YAC (no. 2) into cosmids. At least one of these cosmids (0.38) hybridizes to sequences that bracket the translocation breakpoint, as demonstrated by both Southern blot and FISH analysis. These observations confirm and substantiate our previous findings. In addition, cosmid 0.38 should be a valuable instrument for the ultimate isolation and identification of the gene(s) involved in the development of synovial sarcoma.

Animals↗
PubMed1992

Verification of isochromosome 12p and identification of other chromosome 12 aberrations in gonadal and extragonadal human germ cell tumors by bicolor double fluorescence in situ hybridization.

A diverse group of gonadal and extragonadal human germ cell tumors (GCT) and GCT-derived cell lines was examined for the presence of an i(12p) marker chromosome and/or other abnormalities involving chromosome 12, especially 12p, by bicolor double fluorescence in situ hybridization (FISH). For this purpose three probes, pBS-12, M28, and p alpha 12H8, were used, allowing specific identification of the entire chromosome 12, its short arm, and its pericentromeric region, respectively. The presence of one or more copies of a genuine i(12p) chromosome could be demonstrated in three GCT of the testis, in one ovarian GCT, in one dysgenetic GCT, and in one extragonadal intracranial GCT. Moreover, additional aberrations involving chromosome 12 were shown to be present not only in i(12p) minus but also in i(12p) positive GCT. These data suggest that the occurrence of such aberrations may be a common, although less clearly perceptible and frequent, phenomenon in human GCT.

Brain Neoplasms↗
PubMed1992

Cytogenetics of a case of cardiac myxoma.

The cytogenetic study of a case of cardiac myxoma revealed a 46,XY,der(7)t(7;17) (p21;p11),+der(10)t(10;?)(q22;?),+der(12)t(12;?)(p12;?),del(17)(p11) chromosomal pattern. This case adds a new example of chromosomal abnormalities in benign neoplasms.

Chromosome Aberrations↗
PubMed1992

Cytogenetic analysis of the mature teratoma and the choriocarcinoma component of a testicular mixed nonseminomatous germ cell tumor.

We karyotyped two histologically distinct components with different metastatic behavior of a testicular nonseminomatous germ cell tumor. The two components showed an almost identical chromosomal pattern. These almost identical karyotypes of the two components with different metastatic potential suggest that the difference in biologic behavior might result from subtle differences (on microscopic or submicroscopic level) in chromosomal pattern or that these differences are predominantly epigenetically determined and depend primarily on the lineage of differentiation of the tumor component. Trophoblastic differentiation results in an aggressive, angioinvasive tumor but in development of teratoma in a tumor with low malignant potential.

Adult↗
PubMed1992

The translocation (6;9) (p23;q34) shows consistent rearrangement of two genes and defines a myeloproliferative disorder with specific clinical features.

Translocation (6;9)(p23;q34) is a cytogenetic aberration that can be found in specific subtypes of both acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). This translocation is associated with an unfavourable prognosis. Recently, the genes involved in the t(6;9) were isolated and characterized. Breakpoints in both the dek gene on chromosome 6 and the can gene on chromosome 9 appear to occur in defined regions, which allows us to diagnose this type of leukemia at the molecular level. Moreover, because of the translocation a chimeric dek-can mRNA is formed which, as we show here, is an additional target for diagnosis via cDNA-preparation and the polymerase chain reaction (PCR). We studied 17 patients whose blood cells and/or bone marrow cells showed a t(6;9) with karyotypic analysis. Fourteen patients suffered from AML, one patient had a refractory anemia with excess of blasts in transformation (RAEBt), one patient had an acute myelofibrosis (AMF), and one patient a chronic myeloid leukemia (CML). In nine cases studies at the DNA and RNA levels were possible while in seven cases only the DNA could be analyzed. In one case only RNA was available. Conventional Southern blot analysis showed the presence of rearrangements of both the dek gene and the can gene. In both genes, breakpoints cluster in one intron in the patients investigated. The presence of a consistent chimeric dek-can product after cDNA preparation followed by the PCR was demonstrated. We conclude from our data that the t(6;9) is found in myeloproliferative disorders with typical clinical characteristics. This translocation results in highly consistent abnormalities at the molecular level.

Adolescent↗
PubMed1992

Serum lactate dehydrogenase isoenzyme 1 activity in patients with testicular germ cell tumors correlates with the total number of copies of the short arm of chromosome 12 in the tumor.

The aim of our study was to assess the relationship between the serum lactate dehydrogenase isoenzyme 1 (S-LDH-1) activity in patients with testicular germ cell tumors and the number of copies of the short arm of chromosome 12 (12p) present in tumor. Twenty-seven adult patients with measurable tumor lesions were studied. Twenty-five had three or more copies of chromosome 12 per cell in the tumors. Nineteen had one or more copies of a specific chromosomal abnormality, an isochromosome of the short arm of chromosome 12, i(12p). Fourteen had increased S-LDH-1 levels. S-LDH-1 activity correlated significantly with the product of total tumor volume and the total number of copies of the short arm of chromosome 12 present per cell (total tumor 12p). We conclude that the total number of copies of the short arm of chromosome 12 in the tumors is most probably a factor contributing to the LDH-1 activity released from the tumors.

Adult↗
PubMed1992

Cytogenetics of a case of eccrine spiradenoma.

A cytogenetic study of an eccrine spiradenoma and two lymph node metastases, with a growth pattern and microscopic appearance typical for benign eccrine spiradenoma, revealed a 46,XY-5,del(16)(q22),+mar(t(?;5)(?::5q13----5qter)) karyotype. The finding of the same abnormal karyotype in the tumor and the metastases suggests a relationship between the chromosomal abnormalities and the clinical malignant behavior of this morphologic benign tumor.

Adenoma, Sweat Gland↗
PubMed1992

Ploidy of testicular carcinoma in situ.

The ploidy of carcinoma in situ and invasive germ cell tumors of the adult testis was compared by DNA flow cytometry. Irrespective of the tumor type with which it was associated, the median DNA index of carcinoma in situ was about the same as that of seminomas and higher than the DNA index of invasive nonseminomatous germ cell tumors. These data indicate that seminoma and carcinoma in situ cells are not only phenotypically similar but also have the same ploidy.

Adult↗