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K D Zang

Publications and source records attributed to K D Zang.

At least 55 records · Page 3Linked to original sources
PubMed1995

Isolation and localization of transcribed sequences on human chromosome 22.

Recently, we reported the generation of a heteronuclear (hn) cDNA library from a human x rodent somatic cell hybrid retaining human chromosome 22. Here, we report the characterization and localization of 12 cDNA derived clones from this library. Human-specific cDNA sequences have been selectively amplified by inter-Alu PCR. To exclude Alu transcripts, only clones with inserts larger than 500 bp were analyzed. Ten of the 12 clones were localized by PCR on chromosome 22, with four clones mapping on additional chromosomes. One PCR-localized clone and two additional clones were mapped on chromosome 22 by in situ hybridization. Transcripts in human cells were identified for seven of the eight clones analyzed by RT-PCR. None of the clones showed significant sequence similarities within the GenBank and EMBL databases, indicating that these clones represent previously unknown genes. This is the first report on the isolation of chromosome 22-specific transcripts from a human x rodent somatic cell hybrid.

Animals↗
PubMed1995

Lack of isodisomy for chromosome 22 in disomic meningiomas.

Loss of one copy of chromosome 22 is the most prevalent chromosomal change in meningioma, indicative of a tumor suppressor on chromosome 22. Meningioma retaining both copies of chromosome 22 could be possibly be explained by isodisomy for a meningioma suppressor gene. To investigate whether the chromosomal situation in meningioma is consistent with this hypothesis, we studied 53 cases, using polymorphic probes localized on chromosome 22. loss of one copy of chromosome 22 was found in 14 cases when polymorphic DNA markers were used. Thirty-nine meningiomas studied by karyotyping and molecular probes retained both copies of chromosome 22. The majority of cases (30/39, or 77%) displayed heterozygous banding patterns, indicating the presence of heterologous copies of chromosome 22. Hence, our data provide no evidence for duplication of one parental homolog as a general mechanism in diploid meningioma.

Chromosome Aberrations↗
PubMed1994

Phosphorylation of nm23/nucleoside diphosphate kinase by casein kinase 2 in vitro.

We have investigated phosphorylation of human nucleoside diphosphate kinase (NDPK) and of homologous NDPK from different species by human casein kinase 2 (CK-2). The human NDPK isotypes A and B were phosphorylated by CK-2 in vitro both when the purified proteins and total lysate of HL-60 leukemia cells were used. The homologous NDPK's from Yeast and E. coli were also substrates for CK-2 in vitro, but not Drosophila NDPK. Phosphorylation of all NDPK types by the CK-2 holoenzyme was entirely polyamine-dependent. The CK-2 phosphorylation site in human NDPK A, that was about 2.5 times stronger phosphorylated than was the B isotype, was tentatively assigned to Ser-122. The location of the corresponding residue in the 3D-structure of the 80% homologous Drosophila NDPK suggests that its phosphorylation may directly influence substrate binding and/or catalysis.

Amino Acid Sequence↗
PubMed1994

Coamplification on chromosomes 7p12-13 and 9q12-13 identified by reverse chromosome painting in a glioblastoma multiforme.

DNA amplification is known to occur in approximately 50% of glioblastomas, with the epidermal growth factor receptor (EGFR) gene being the most frequently amplified. Whereas previous amplification studies have largely been limited to the analysis of known tumor-related genes, reverse chromosome painting allows us to search for as yet unidentified amplified domains. Here, we report the analysis of a glioblastoma multiforme by reverse chromosome painting. Hybridization signals were found on chromosome 7p12-13 and chromosome 9q12-13. Standard Southern blot analysis revealed amplification of the EGFR gene, which is localized on band 7p13. These findings corroborate previous reports on coamplification of sequences on different chromosomes in glioblastoma.

Aged↗
PubMed1994

Isolation and characterization of the human genomic locus coding for the putative metastasis control gene nm23-H1.

Nm23-H1 gene expression is inversely correlated with tumor metastatic potential in certain tumors, including melanomas, breast carcinomas, and hepatocellular carcinomas. Using nm23-H1 c-DNA primer and genomic polymerase chain reaction (PCR) amplification, we purified three PCR fragments (one of 4kb and two of 2 kb) covering the whole human genomic locus of the gene (8.460bp). We recombined the PCR products into pUC18 and produced a restriction map to perform subcloning. Complete sequencing of genomic PCR fragments, including the whole coding region of nm23-H1, revealed that the gene consists of five exons and four introns spanning 8.5kb. A sequence homology analysis between human nm23-H1 and the homolog gene of the rat (NDP-K beta) shows that exon-intron boundaries are well conserved between these two species.

Amino Acid Sequence↗
PubMed1994

DNA aneuploidy in prostatic adenocarcinoma: a frequent event as shown by fluorescence in situ DNA hybridization.

Fluorescence in situ hybridization (FISH) using specific DNA probes for chromosomes 1, 7, 10, and Y was performed on 53 prostatic tissue samples obtained from 33 radical prostatectomy specimens and two benign control specimens. The 53 samples from carcinomatous prostates included 33 cancerous and 20 noncancerous samples. Additionally, four metastatic lymph node specimens were examined. Clonal chromosome abnormalities were observed in 78% of the tumors studied. They were detected in a higher proportion in stage pT2 and pT3 tumors (86% and 88%, respectively) compared with stage pT1 tumors (25%). No stage pT4 tumor was analyzed. There was evidence of remarkable focal intratumoral heterogeneity documented by the study of two samples from the same tumor in three of six cases. Comparing FISH determined ploidy patterns with DNA flow cytometry (FCM) in 22 samples, FISH showed aneuploidy whereas FCM showed none.

Adenocarcinoma↗
PubMed1994

DNA amplifications on chromosomes 7, 9 and 12 in glioblastoma detected by reverse chromosome painting.

Biopsies and cell culture, respectively, of four human glioblastoma multiforme (WHO 4) have been evaluated for gene amplification using reverse chromosome painting. Three of the tumours showed amplified domains within chromosome bands 12q13-15. The exact localisation and extension of the amplified domains, however, varies within this region. Southern blot analysis revealed amplification of the GLI oncogene in two of the glioblastomas which were found to contain amplified domains within 12q13-15. Reverse chromosome painting also identified amplified domains within bands 7q21 and 9p23-24. Amplification within region 9p23-24 has previously not been reported in glioblastoma. The amplified domain encompassing 9p23-24 was detected in the same glioblastoma which contained an amplification unit within bands 12q13-14. These data, together with previous reports, indicate that amplifications are predominantly found on chromosomes 7, 9 and 12 in glioblastoma. In addition, this study provides further evidence that coamplification is not a rare event in glioblastoma.

Chromosomes, Human, Pair 12↗
PubMed1994

Detection of numerical chromosome aberrations in brain tumours by fluorescence in situ hybridization on smear preparations of small tumour biopsies.

We present a technique for the preparation and interphase cytogenetic analysis of native tumour cell nuclei from smear preparations of small biopsies of human brain tumours. The presence of tumour-specific numerical chromosome aberrations can be determined by fluorescence in situ hybridization (FISH) analysis using chromosome-specific repetitive DNA probes. The FISH analysis of smear preparations provides cytogenetic information about brain tumour samples, within 2 days, avoiding time-consuming and artefact-prone tumour cell culture.

Biopsy↗
PubMed1994

[18FDG-PET in intracranial meningiomas versus grading, proliferation index, cellular density and cytogenetic analysis].

62 intracranial meningiomas in 60 patients were studied with 18FDG-PET prior to neurosurgery in order to evaluate the relationship between 18FDG uptake and biological aggressiveness of the tumors. Histopathological grading, cellular density, Ki-67 proliferation index and evidence of chromosomal aberrations were used to assess tumor aggressiveness. Significantly elevated 18FDG uptake was found in grade 2- and 3- compared to grade 1-meningiomas, in tumors of high cellularity compared with those of low cellularity, and in meningiomas with an elevated Ki-67 proliferation index (above 2%). The two meningiomas with the most pronounced chromosomal aberrations revealed the highest 18FDG uptake of all cytogenetically studied meningiomas. We conclude that 18FDG-PET is useful for estimating the biological aggressiveness of intracranial meningiomas.

Adult↗
PubMed1993

High levels of nm23-H1 and nm23-H2 messenger RNA in human squamous-cell lung carcinoma are associated with poor differentiation and advanced tumor stages.

Expression of the candidate metastasis-suppressor gene nm23-H1 has been shown to correlate inversely with metastatic potential in some human tumors, but not in all. Until now, few studies have been carried out on the activity of the homologous nm23-H2 gene in human cancer. No nm23 transcription studies exist for human lung cancer so far. To determine whether the nm23 genes could have a metastasis-suppressor function in non-small-cell lung carcinoma (NSCLC), pulmonary sarcoma and carcinoids, we analysed both nm23-HI and nm23-H2 mRNA levels in 37 tumor samples obtained from patients who underwent potentially curative resection between 1986 and 1990, and in 4 metastatic tumors obtained from autopsy. As compared to corresponding healthy lung parenchyma, both nm23-HI and nm23-H2 transcript levels were elevated in 37 of 41 tumors. The increases in nm23 mRNA expression were stronger in advanced stages of squamous-cell carcinoma, large-cell carcinoma, sarcoma and carcinoids than in early stages of the respective tumor types. Within stages I and II of squamous-cell carcinoma, significantly higher nm23 mRNA levels were found in poorly differentiated tumors than in moderately differentiated ones. Moreover, an inverse correlation between nm23 expression and disease-free survival of the patients was observed. In conclusion, our results indicate that the increased nm23 expression in the analysed tumors is not consistent with the proposed metastasis-suppressor function, but the 2 nm23 genes nevertheless may be implicated in the mechanism of tumor progression.

Adenocarcinoma↗
PubMed1993

Genotypic characterization of prostatic carcinomas: a combined cytogenetic, flow cytometry, and in situ DNA hybridization study.

Cytogenetic studies were performed on 36 biopsies obtained from 26 primary prostatic adenocarcinomas. Following histopathological characterization of control sections, the biopsies were investigated using metaphase cytogenetics, DNA flow cytometry, and fluorescence in situ DNA hybridization. In 12 specimens, no carcinoma was found in control sections by histopathological means. In 24 carcinoma biopsies clonal aberrations were detected in 15 specimens. Tetraploidy as sole aberration was detected in five specimens. Loss of the Y chromosome was seen in eight samples. Only one tumor revealed structural abnormalities. Eight samples were found to be normal (46,XY). Remarkably, nonclonal chromosome aberrations, particularly marked chromosome loss, were frequently detected in prostatic carcinomas and premalignant lesions (prostatic intraepithelial neoplasia). In the series of biopsies investigated by means of cytogenetics and flow cytometry, biopsies with aneuploid DNA content were found to be cytogenetically normal. Conversely, the cytogenetically aberrant clones were found to be of diploid DNA content. Evidence of focal intratumoral heterogeneity was revealed by cytogenetics, flow cytometry, and in situ hybridization.

Aged↗
PubMed1993

Bilateral multicentric papillary renal tumors with heteroclonal origin based on tissue-specific karyotype instability.

BACKGROUND: Papillary chromophilic renal tumors were cytogenetically characterized by combined trisomies 7 and 17 along with other numeric chromosome aberrations. They occurred as bilateral multifocal lesions. METHODS: A patient was presented who simultaneously developed bilateral multicentric papillary renal tumors. Tissue specimens from six tumors and tumor-free kidneys were cytogenetically characterized. RESULTS: The tumors showed trisomy of chromosomes 7, 16, and 17 along with various other numeric abnormalities. In normal tissue from both kidneys, a wide variety of clonal and nonclonal numeric and structural chromosome aberrations were found. CONCLUSIONS: The cytogenetic heteroclonality of the tumors strongly favors the assumption that they arose as independent primaries. A tissue-specific karyotype instability may be the basic event of multiple tumorigenesis.

Adenoma↗
PubMed1993

Telomeric associations and loss of telomeric DNA repeats in renal tumors.

In a series of cytogenetically analyzed renal tumors of different histological types (chromophobe carcinoma, clear-cell carcinoma, chromophilic carcinoma, and oncocytoma) and normal renal tissue, the length of the telomeric DNA repeats was assessed using a (TTAGGG)3 oligonucleotide probe. A strong correlation was noted between pronounced telomere shortening and the appearance of telomeric associations of chromosomes. These data suggest an etiologic role of the loss of telomeric DNA repeats in the formation of telomeric associations and a possible involvement of this mechanism in the pathogenesis of chromosome aberrations in human tumors.

Adenocarcinoma↗
PubMed1993

Clonal chromosome aberrations in cell cultures of synovial tissue from patients with rheumatoid arthritis.

Cytogenetic analysis of primary cell cultures and/or passages 1-3 of synovial tissue from seven patients with rheumatoid arthritis was performed. As the only recurrent chromosome aberration, trisomy 7 was found in six of seven cultures. In four cultures, trisomy 7 occurred as a clonal change in up to 20% of the analyzed cells, with an increase of the proportion of cells with +7 with the duration of the in vitro culture. Apart from this recurrent change, a variety of partly clonal, partly nonclonal numerical and structural chromosome aberrations were observed in all cases. These findings support the view that clonal chromosome aberrations may play a role in the pathogenesis of invasive growth of the synovial tissue in rheumatoid arthritis although the localized synovial hyperproliferation is not a true neoplastic process.

Arthritis, Rheumatoid↗
PubMed1993

Immunophenotyping of mitotic cells from long-term cultures of chorionic villi.

Chromosomal mosaicism in chorionic villus samples (CVS) may arise from different sources, such as clonal diversity within the chorionic tissue or contamination with maternal cells. To determine the origin of karyotyped cells, we compared the immunocytochemical features of mitotic cells in CVS long-term cultures with histological sections of their tissue of origin, i.e. chorionic villi. Immunolabelling of intermediate filaments specific for epithelial cells (cytokeratin) and mesenchymal cells (vimentin) established that mitoses yielded from CVS long-term cultures indeed stem from independently growing clones derived from both the epithelial and mesenchymal parts of the chorionic villi. Thus, mosaicism in CVS cultures may reflect true genetic heterogeneity within the biopsy. However, epithelial chorionic cells undergo in vitro metaplasia leading to co-expression of cytokeratins and vimentin. Fetal-specific immune markers (beta-HCG and SP1-glycoprotein) are not reliably expressed in CVS cell culture.

Chorionic Gonadotropin↗
PubMed1993

Generation of a chromosome-22-specific c-DNA library as confirmed by FISH analysis.

We have recently developed a strategy for the rapid enrichment of c-DNA fragments from selected human chromosomes. Heteronuclear RNA (hn-RNA) is isolated from a somatic cell hybrid that retains a single human chromosome in a rodent background. Following c-DNA synthesis, human sequences are selectively amplified by the Alu polymerase chain reaction (Alu-PCR). Here we have applied this protocol for the selective isolation of novel c-DNAs encoded by chromosome 22. Fluorescence in situ hybridization has been used to confirm the chromosome-22-specific origin of the c-DNA fragments. Controls show DNAse-free RNase-treated hn-RNA results in no c-DNAs or Alu-PCR products. As demonstrated by competitive in situ suppression hybridization (CISS), the majority of the Alu-PCR products from hybrid GM 10027 are located on chromosome 22. Without competition, hybridization signals have also been identified on other human chromosomes. These unspecific hybridization signals result from Alu sequences and can successfully be reduced by competition with cot 1 DNA. This is the first report of the use of CISS for the localization of chromosome-specific c-DNAs.

Animals↗
PubMed1993

Recurrent t(12;19)(q13;q13.3) in intracranial and extracranial hemangiopericytoma.

We report on a recurrent intracranial hemangiopericytoma cytogenetically studied after short-term culture. The tumor had a uniform karyotype 47,XX,add(7)(q21),t(12;19)(q13;q13.3),del(13)(q14q22), +21. Remarkably, one case with an identical reciprocal (12;19) translocation has been previously reported as the sole cytogenetic change in a recurrent retroperitoneal hemangiopericytoma. This nonrandom structural change may characterize a subentity of hemangiopericytoma and might be of diagnostic value.

Aneuploidy↗