Biomedical subjects

A R Brothman

Publications and source records attributed to A R Brothman.

At least 55 records · Page 3Linked to original sources

PubMed1995

Homologous centromere association of chromosomes 9 and 17 in prostate cancer.

Chromosomal loss in cancer cells has been observed by nonisotopic in situ hybridization using pericentromeric probes. Accurate determination of this loss depends upon efficient hybridization and visualization of all probe signals in a two-dimensional field. Close association of homologous centromeres, reported in various normal and tumor tissues, can complicate evaluation and interpretation, resulting in the overestimation of actual chromosome loss. Using pericentromeric FISH probes for chromosomes 9 (classical and beta-satellite) and 17 (alpha-satellite), as well as 17q-specific phage probes, we tested the frequency of homologous centromere association in normal and malignant prostate tissues and lymphoblastoid cells. We found that the pericentromeric region of both chromosome 9 and 17 associated in prostate tissues, but only chromosome 9 demonstrated association in the lymphoblastoid cells. The association observed for chromosome 9 in both cell types appeared to be limited to the classical satellite III-type of heterochromatic, pericentromeric DNA. Using a single-copy probe along with the chromosome 17-specific pericentromeric probe, we determined that the association did not extend to the chromosome arms, but was limited to the pericentromeric region of chromosome 17. To accurately determine chromosome loss, we advocate the use of single-copy probes in addition to, or in place of, pericentromeric probes.

Adult↗

PubMed1995

Mutation of the MXI1 gene in prostate cancer.

The Mxi1 protein negatively regulates Myc oncoprotein activity and thus potentially serves a tumour suppressor function. MXI1 maps to chromosome 10q24-q25, a region that is deleted in some cases of prostate cancer. We have detected mutations in the retained MXI1 alleles in four primary prostate tumours with 10q24-q25 deletions. Two tumours contained inactivating mutations, whereas two others contained the identical missense mutation. Fluorescence in situ hybridization also demonstrated loss of one MXI1 allele in an additional tumour lacking chromosome 10 abnormalities. MXI1 thus displays allelic loss and mutation in some cases of prostate cancer that may contribute to the pathogenesis or neoplastic evolution of this common malignancy.

Alleles↗

PubMed1995

Strong correlation of elastin deletions, detected by FISH, with Williams syndrome: evaluation of 235 patients.

Williams syndrome (WS) is generally characterized by mental deficiency, gregarious personality, dysmorphic facies, supravalvular aortic stenosis, and idiopathic infantile hypercalcemia. Patients with WS show allelic loss of elastin (ELN), exhibiting a submicroscopic deletion, at 7q11.23, detectable by FISH. Hemizygosity is likely the cause of vascular abnormalities in WS patients. A series of 235 patients was studied, and molecular cytogenetic deletions were seen in 96% of patients with classic WS. Patients included 195 solicited through the Williams Syndrome Association (WSA), plus 40 clinical cytogenetics cases referred by primary-care physicians. Photographs and medical records of most WSA subjects were reviewed, and patients were identified as "classic" (n = 114) or "uncertain" (n = 39). An additional 42 WSA patients were evaluated without clinical information. FISH was performed with biotinylated ELN cosmids on metaphase cells from immortalized lymphoblastoid lines from WSA patients and after high-resolution banding analysis on clinical referral patients. An alpha-satellite probe for chromosome 7 was included in hybridizations, as an internal control. Ninety-six percent of the patients with classic WS showed a deletion in one ELN allele; four of these did not show a deletion. Of the uncertain WS patients, only 3 of 39 showed a deletion. Of the 42 who were not classified phenotypically, because of lack of clinical information, 25 patients (60%) showed a deletion. Thirty-eight percent (15/40) of clinical cytogenetics cases showed an ELN deletion and no cytogenetic deletion by banded analysis. These results support the usefulness of FISH for the detection of elastin deletions as an initial diagnostic assay for WS.

Abnormalities, Multiple↗

PubMed1994

Tumorigenicity of SV40 T antigen immortalized human prostate epithelial cells: association with decreased epidermal growth factor receptor (EGFR) expression.

Our primary objectives were to: 1) develop a system for the study of prostatic tumor evolution; and 2) examine the role of the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) pathway in prostate tumor progression. Adult human prostate epithelial cells previously immortalized by transfection with the SV40 T antigen gene (P69SV40T) produced tumors in only 2/18 mice with a 6 month latency period. Reinjection of cells recovered from these tumors after 1 or 2 cycles of growth in nude mice produced tumors in 2/4 and 2/3 mice with markedly decreased latent intervals of 12, 25, 25 and 25 days each. The chromosomal complement of each tumor was human, consistently pseudodiploid, and retained the Y chromosome. In both anchorage-independent and adherent cell growth assays, EGF stimulated proliferation by approximately 2-fold in both the parental P69SV40T line and the tumor sublines. The tumor sublines expressed less EGFR protein than the parental line, as assessed by Western immunoblotting and flow cytometric analysis. Immunoprecipitation revealed increased production of the 18 and 25 kDa TGF-alpha precursors parallel to decreases in detectable EGFR. The growth of both the parental P69SV40T line and the tumor sublines was inhibited by a neutralizing antibody to TGF-alpha under serum-free defined conditions. Inclusion of the TGF-alpha neutralizing antibody consistently inhibited the proliferation of the tumor sublines more than P69SV40T in both proliferation and [3H]thymidine incorporation assays. This finding suggests that the increased tumorigenicity and decreased latent interval observed among the human prostate tumor cells is partially due to activation of the TGF-alpha/EGFR autocrine network.

Animals↗

PubMed1994

Assignment of human xanthine dehydrogenase gene to chromosome 2p22.

Xanthine dehydrogenase (XDH, EC 1.1.1.204) oxidizes a variety of purines, pterins, and other heterogenic nitrogen compounds, serving as a rate-limiting enzyme in nucleic acid degradation. The genetic defect of XDH results in hereditary xanthinuria and other disorders in purine metabolism. Based on the cloning and sequencing results of human XDH cDNA in our laboratory, we studied the localization and sublocalization of the XDH gene. A Version 3.0 human-hamster somatic cell hybrid PCRable DNA panel and specific PCR primers derived from human XDH cDNA for amplification were used to assign the XDH gene to human chromosome 2. The fidelity of the PCR product was confirmed by nucleotide sequencing the PCR product. The assignment of the XDH gene to chromosome 2 at band p22 was established by fluorescence in situ hybridization on human metaphase chromosomes using a clone from a pWE 15 cosmid library containing the XDH gene. The results should be useful for further studies of the molecular basis for hereditary xanthinuria and other genetic disorders related to abnormal XDH activity.

Animals↗

PubMed1994

Evaluation of 20 archival prostate tumor specimens by fluorescence in situ hybridization (FISH).

Analysis of 20 primary prostatic tumors (local Gleason grades ranging from 1 to 4) was performed on archival material obtained from formalin-fixed, paraffin-embedded blocks. Alpha satellite probes specific for the pericentric regions of chromosomes 12, 17, X, and Y were used in fluorescence in situ hybridization (FISH) assays for the examination of aneusomies for these chromosomes. Eighty percent of specimens (16/20) showed significant loss of chromosome 17 and 55% (11/20 specimens) also showed significant loss of chromosome 12; all specimens that lost chromosome 12 lost chromosome 17. Gain of the X chromosome was observed in 40% (8/20) of specimens, all but one of which also showed loss of chromosome 17. While the specimens showing gain of the X chromosome may represent polyploid cells, only one specimen also showed significant gain of chromosomes 12 and 17, suggesting that both of these chromosomes may be lost in hyperdiploid prostate cancers. Loss of the Y chromosome was not statistically significant. This study thus indicates that loss of chromosome 17 is a frequent and likely early event in prostatic cancer.

Aged↗

PubMed1994

Multiple congenital anomalies in a man with (X;6) translocation.

X;autosome translocations in humans, often associated with congenital anomalies or with gonadal dysgenesis syndromes, are informative for the study of X-linked gene expression and of the phenomenon of X chromosome inactivation. When such translocations occur in association with multiple congenital anomaly (MCA) syndromes, the observed phenotypes are not always attributable solely to disruption of specific genes, if X-inactivation spreads onto the translocated autosome, rendering some distal genes inactive. We report on a man with multiple congenital anomalies and a maternally inherited (X;6)(p22.1;p25) translocation. He has abnormalities not described in the Klinefelter or 6p deletion syndromes. His unique findings constitute a recognizable syndrome, which is likely caused by disomy for a region of Xp in conjunction with a partial 6p deletion.

Abnormalities, Multiple↗

PubMed1994

Functional characteristics of in vivo induced neutrophils after differentiation therapy of acute promyelocytic leukemia with all-trans-retinoic acid.

The authors describe the functional capabilities of in vivo induced neutrophils from a patient with acute promyelocytic leukemia (French-American-British M3v) treated with differentiation therapy using all-trans-retinoic acid (45 mg.m-2.day-1). The induced neutrophils from the leukemic clone appeared in the blood 7 days after therapy. Normal neutrophils, presumably derived from nonclonal normal hematopoiesis, appeared 15 days after the initiation of therapy. The induced neutrophils were separated from normal neutrophils by density gradient centrifugation. Their origin was established by fluorescence in situ hybridization. The induced neutrophils were morphologically atypical but stained for myeloperoxidase (Sudan black B) and AS-D chloroacetate esterase and were negative for alpha-naphthyl butyrate esterase. Induced neutrophils were functionally mature, showing nitroblue tetrazolium reduction in 72% of the cells compared with 84% in the normal neutrophil fraction. Both the rate and total killing of Staphylococcus aureus (American Type Culture Collection Strain 25923) were normal in both neutrophil fractions. Random locomotion was equivalent and within the normal reference range in both fractions; however, using the under-agarose technique, induced neutrophils showed a minor chemotactic defect in response to both n-formyl-methionyl-leucyl-phenylalanine (score 292, normal 338-868) and complement-derived chemotactic factors (score 420, normal 457-1408). At autopsy, induced neutrophils infiltrated necrotic myocardial tissue, suggesting a normal response to inflammatory stimuli.

Adult↗

PubMed1994

Aneusomy of chromosomes 7 and 17 detected by FISH in prostate cancer and the effects of selection in vitro.

Twenty prostate tumor specimens, obtained from radical prostatectomies, and two lymph node metastases were examined by classical and molecular cytogenetic methods. A sample from each tumor was analyzed histologically and used for touch preparations. Adjacent samples were used for preparation of single-cell suspensions before cell culture (DirFISH) and for establishing cell cultures, which were subsequently harvested for classical G-banding analysis. Fluorescence in situ hybridization (FISH) was performed on touch preparations, DirFISH, and cells obtained from tissue culture. Biotinylated pericentromeric probes for chromosomes 7 and 17, in addition to a digoxigenin-labeled X-chromosome probe, were used in a dual-color FISH assay. The results indicated that, in uncultured tumor cells, chromosome 17 was lost in 55% of specimens, chromosome 7 was gained in 16% of specimens, and 9% of specimens showed large tetraploid populations. After cell culture, 23% of specimens showed loss of chromosome 17, no specimens showed gain of chromosome 7, and no tetraploid populations were present. This study suggests that loss of chromosome 17 may play an important role in the development of prostate cancer, and that genetic changes observed after selection in vitro may not represent those in the original tumor.

Aneuploidy↗

PubMed1993

Multiple craniofacial anomalies associated with an interstitial deletion of chromosome 1(q21->q25).

We present a patient with an interstitial deletion of the chromosome 1q21->q25 that was diagnosed by amniocentesis. Significant malformations included: microbrachycephaly, bilateral cleft lip and palate, micrognathia, short neck, and athyroidia. The autopsy results demonstrate an overlap with several other postnatally ascertained patients and document the phenotype prenatally.

Amniocentesis↗

PubMed1993

Prenatal detection of an inverted X chromosome in a male.

An unusual case of an X chromosome with a pericentric inversion (p11.3q21.3) was detected prenatally in a male fetus. This inversion has not been previously characterized. Although the inverted chromosome was transmitted through the mother, no living males on the maternal side were detected with the aberrant chromosome. Replication studies were performed on cultures of maternal peripheral blood lymphocytes, and it was determined that the inverted X chromosome was early replicating in approximately half of the cells. Following genetic counseling, the pregnancy was continued and a healthy male infant was delivered at term. Cytogenetic analysis of peripheral blood performed in the newborn period confirmed the prenatal findings. The child is developing normally at 3 years of age.

Adult↗

PubMed1992

Analysis of prostatic tumor cultures using fluorescence in-situ hybridization (FISH).

Analysis of ten primary prostatic tumor cultures using fluorescence in-situ hybridization (FISH) with pericentromeric probes for chromosomes 7, 8, 10, 16, 17, and 18 revealed aneusomies in nine of these specimens. Classical cytogenetics by G-banding indicated that only four of those same ten specimens had any (but not consistent) clonal abnormalities. This preliminary study suggests that aneusomy is a common event in early-stage prostatic tumors, and also supports the notion that multiple chromosomes are involved. In combination with routine cytogenetic analysis, FISH is thus likely to be a powerful tool in the evaluation of prostatic cancer.

Chromosome Aberrations↗

PubMed1992

Confirmation of true mosaic trisomy 20 in a phenotypically normal liveborn male.

A new case of prenatally detected mosaic trisomy 20 (79% trisomy 20 cells in amniocyte cultures) that was confirmed in newborn tissue is presented. A healthy male infant was delivered at term, with no dysmorphology or apparent malformations; this baby is developing normally. Twenty-five percent of foreskin and 17% of fetal cord cells also showed trisomy 20, while no trisomic cells were detected in newborn blood. High frequency mosaicism for trisomy 20 in this case was thus due to true embryonic origin. Extensive counseling and prenatal follow-up in this case led to an unaffected liveborn, and guarded optimism may be warranted for future cases of mosaic trisomy 20 detected prenatally.

Amniocentesis↗

PubMed1992

Characterization of 10 marker chromosomes in a prostatic cancer cell line by in situ hybridization.

Marker chromosomes contain potentially valuable information about breakpoints in cancer. However, routine banding procedures, by themselves, provide only limited information about the identity of marker chromosomes. In this study, the use of fluorescence in situ hybridization (FISH) with chromosome-specific centromeric probes and whole-chromosome-specific DNA libraries greatly enhanced the identification of 10 marker chromosomes in the primary prostatic cancer cell line PPC-1. Centromeric probes for chromosomes 1, 2, 3, 4, 10, 12, and 17 and whole-chromosome paint libraries for chromosomes 1, 2, 3, 4, 8, and 12, in conjunction with analysis of G-banded metaphases, allowed the major portion(s) of these 10 PPC-1 marker chromosomes to be defined. The results increase the number of identifiable chromosomal breakpoints in this cell line from 9 to 28 sites.

Centromere↗

PubMed1992

Trisomy 17p associated with Charcot-Marie-Tooth neuropathy type 1A phenotype: evidence for gene dosage as a mechanism in CMT1A.

Charcot-Marie-Tooth neuropathy type 1A (CMT1A) is associated with a DNA duplication on chromosome 17, band p11.2, resulting in partial trisomy for this region in CMT1A patients. The 17p11.2 duplication may lead to the CMT1A phenotype either through disruption of a gene at the duplication breakpoint junction or by trisomic dosage and overexpression of a gene within the duplication. To test the latter model, we evaluated a patient with complete translocation trisomy 17p for signs of CMT1A. In addition to the dysmorphic features seen in trisomy 17p, a neurologic examination and electrophysiologic studies detected a demyelinating neuropathy, compatible with CMT1A. A karyotype on the patient's father found a balanced translocation [t(14;17)] with breakpoints on chromosome 17 in either band p11.1 or proximal p11.2. An analysis of the patient's DNA confirmed trisomy 17p and mapped the translocation breakpoint to a region in 17p11.2, proximal to the duplication breakpoint in CMT1A. Our observations in this patient with trisomy 17p are relevant to an understanding of the genetic mechanism in CMT1A and provide strong evidence that gene dosage through segmental trisomy for 17p11.2 results in the CMT1A phenotype.

Adolescent↗

PubMed1991

Apparent Opitz BBBG syndrome with a partial duplication of 5p.

We describe a patient with a paracentric inversion and partial duplication of chromosome 5p. In addition this patient presented with a malformation pattern consistent with Opitz BBBG syndrome. This implies that the gene responsible for this single gene defect may be located within this duplicated region.

Abnormalities, Multiple↗

PubMed1991

Cytogenetic evaluation of 20 cultured primary prostatic tumors.

We report the cytogenetic evaluation of 20 cultured cell strains derived from primary prostatic adenocarcinomas obtained from radical prostatectomies. The majority of the strains contained cells with only normal male karyotypes (46,XY), but cytogenetically abnormal clonal populations were found in five strains. Two of those strains contained aberrations involving the Y chromosome, one with a -Y and one with a +Y. Three strains (one of which also had the XYY karyotype) exhibited cells with double-minute chromosomes and four strains contained near tetraploid cells.

Adenocarcinoma↗

PubMed1991

Metastatic properties of the human prostatic cell line, PPC-1, in athymic nude mice.

Limitation in the number of human prostatic cell lines has created a gap in knowledge regarding the in-vivo progression of this common cancer. The recently isolated primary prostatic carcinoma cell line, PPC-1, has been shown to be tumorigenic in athymic nude mice. These cells are now shown to form metastases to secondary sites in 10 of 12 animals in this initial study. Metastases were localized to lung and lymph nodes, and the tumor histology closely resembled that of the undifferentiated, rapidly dividing primary tumors. This is the first report describing the metastatic properties of a primary prostatic cancer cell line. PPC-1 cells are therefore likely to represent a good model system for the study of human prostate cancer progression.

Animals↗