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A R Brothman

Publications and source records attributed to A R Brothman.

71 records · Page 4Linked to original sources
PubMed1990

Frequency and pattern of karyotypic abnormalities in human prostate cancer.

The cytogenetic evaluation of 30 cultured primary prostatic cancer specimens obtained during radical prostatectomies of patients with relatively early stage disease is reported. The majority of specimens examined showed a normal male karyotype, 46,XY. Nine samples contained clonally abnormal populations including five specimens which were hyperdiploid (modal range, 65-92 chromosomes), one specimen containing double minute chromosomes, and three containing structural aberrations. Loss of the Y chromosome and a partial trisomy for chromosome 4 was observed in a sample from one patient. Another sample showed a translocation between the long arms of chromosomes 5 and 7. The only tumor obtained from a previously irradiated patient contained no normal cells, a modal chromosome number of 45, loss of chromosomes 2 and Y, and multiple structural rearrangements. The appearance of any clonal cytogenetic abnormality correlated in general with a poorly differentiated state of cancer. A survey of all available previous cytogenetic data on human prostate adenocarcinoma indicated that the loss of chromosomes 1, 2, 5, and Y, the gain of chromosomes 7, 14, 20, and 22, and rearrangements involving chromosome arms 2p, 7q, and 10q are the most common changes observed. This suggests that, although the assignment of a single chromosomal aberration as a marker for early stage prostatic cancer is unlikely, several consistent "hotspots" might be of significance in the etiology of this disease.

Chromosome Aberrations↗
PubMed1989

Phenotypic and cytogenetic characterization of a cell line derived from primary prostatic carcinoma.

A new cell line, PPC-I, has been established from a specimen obtained from a patient with a poorly differentiated adenocarcinoma of the prostate. This is the first line of its type derived from a primary prostatic tumor site. PPC-I cells have become immortalized in culture, exhibit transformation parameters including relaxed growth factor requirements and anchorage-independent growth, and are highly tumorigenic in nude mice. Cytogenetic studies by G-banding revealed a grossly abnormal karyotype, with a modal chromosome number of 84, multiple marker chromosomes including both homogeneously staining regions and double minutes and clonal loss of chromosomes 3, 5, 10, 15 and Y.

Aged↗
PubMed1989

Cytogenetic analysis of four primary prostatic cultures.

Primary cell cultures were established from tissue specimens obtained from patients undergoing transurethral resection of the prostate. Cytogenetic analysis of these cultures revealed a normal male chromosomal complement from one and a 45,X karyotype from another patient with benign prostatic hyperplasia. In addition, a normal male chromosomal complement was observed from a moderately differentiated prostatic carcinoma, and a grossly abnormal karyotype was observed from a poorly differentiated adenocarcinoma of the prostate. This latter specimen contained a modal chromosome number of 84 with several consistent marker chromosomes including homogeneous staining regions and double minutes, and no normal chromosomes 3, 5, 10, 15 or Y. Primary prostatic cell cultures exhibit epithelial-specific keratin intermediate filament proteins, and, in conjunction with cytogenetic analysis, provide a model for the study of human prostate cancer.

Chromosome Aberrations↗
PubMed1987

Cultured Bloom's syndrome substrains: a relationship between growth in low serum and the expression of double minute chromosomes.

Four Bloom's syndrome fibroblast strains were examined for chromosome changes, immortalization, tumorigenicity, anchorage independent growth, and the ability to grow in low serum. Only one strain (GM 1492) exhibited some of these characteristics, which are generally associated with neoplastic cells. Strain GM 1492 also exhibited a low frequency of cells that contained double minute chromosomes. Substrains from GM 1492 were cloned, and showed that some of the above characteristics were expressed as a heritable trait. Karyotype instability (heteroploidy) was seen in all clones studied, with modal chromosome numbers ranging from near-diploid to near-tetraploid, as confirmed by DNA content distributions. Although no clones studied were tumorigenic in nude mice or immortalized, some showed an increased cellular proliferative capacity. Several clones were isolated after growth in 1% fetal bovine serum, and these all showed an increased expression of double minute chromosomes. Two of these 1% serum-isolated clones, (1492/clone 3-1% and clone 8-1%) were further studied by G-banding analysis, and found to show specific chromosomal anomalies. Clone 3 showed monosomy for chromosomes #4, #13, and #19, along with the absence of both copies of chromosome #7 but with both i(7p) and i(7q) chromosomes consistently seen. Clone 8 showed monosomy for chromosome #13. Preliminary experiments using DNA slot blots indicated that erb a and b, v-fes, v-mos, c-myc, n-myc, v-src, and v-sis showed no sequence amplification in GM 1492 cells or subclones.

Animals↗
PubMed1986

Spontaneous immortalization rate of cultured Chinese hamster cells.

Chinese hamster cell cultures derived from either fetal cell suspensions or adult ear clippings invariably became permanent cell lines during conventional subcultivation. The immortal cell cultures arose from rare spontaneous cellular events during the in vitro cultivation of cells with limited proliferative capacity. Immortality was not related to rare, precommitted cells from the animals. The expansion of clones of cells with limited life-span to form permanent cell lines was routinely successful only when the initial, unsubdivided culture achieved a total number in excess of 10(6) cells. On the basis of this observation, a serial clonogenicity assay was developed for determining the life-span of the cells with limited proliferative capacity and for determining whether a cell population is immortal. In addition, the technique of clonal expansion was used for a fluctuation analysis to determine the rate of immortalization. This analysis yielded a rate of 1.9 X 10(6) per cell per generation.

Animals↗
PubMed1986

Preneoplastic phenotype and chromosome changes of cultured human Bloom syndrome fibroblasts (strain GM 1492).

The Bloom syndrome fibroblast strain, GM 1492, was examined for phenotypic properties generally associated with neoplastic cells. A serial clonogenicity assay indicated that these cells can proliferate in culture, achieving approximately twice the number of population doublings as compared to normal human skin fibroblasts. Strain GM 1492 appeared to be partially transformed in that these cells showed a slight degree of anchorage independence when grown in methylcellulose, and also appeared to have relaxed growth requirements compared to normal fibroblasts. GM 1492 cells are heteroploid, with 20 to 80 chromosomes/cell and a modal chromosome number of 44. Cytogenetic analysis of G-banded metaphase chromosomes indicated that most cells contained at least one copy of each normal human chromosome, and many cells exhibited only aneuploidies with no detectable chromosomal rearrangements. Minute chromosomes were seen in a few of the metaphase cells examined. GM 1492 cells did not form tumors in athymic nude mice. Since many of the characteristics of GM 1492 cells are similar to those seen only in tumor cells, but the strain is nontumorigenic, we suggest that GM 1492 cells are preneoplastic and thus represent an ideal system for the in vitro study of human neoplastic progression.

Animals↗
PubMed1985

Cellular uptake and localization of fluorescent derivatives of phorbol ester tumor promoters.

The synthetic fluorescent derivatives of 12-O-tetradecanoylphorbol-13-acetate (TPA), dansyl-TPA, dansyl-TPA-20-acetate and dansyl-TPA-13-desacetate, have ID50 values in the [3H]PDBu binding assay of 2nM, 30nM and 1000nM respectively; the ID50 value of TPA is 4nM. Dansyl-TPA is also equipotent with TPA as an activator of protein kinase C(PKC) producing half maximum stimulation at 2nM. Dansyl-TPA-13-desacetate is almost as potent as dansyl-TPA, while dansyl-TPA-20-acetate is completely inactive as an activator of PKC. The cellular uptake of these fluorescent TPA derivatives tends to parallel their activity in the [3H]PDBu binding assay. Treatment of C3H 10T1/2 cells with 100nM dansyl-TPA results in intense fluorescence of the entire cytoplasm, while the nucleus is virtually devoid of fluorescence. The uptake of fluorescence is quenched by an excess of TPA. Thus, dansyl-TPA rapidly enters cells and binds to specific sites distributed throughout the cytoplasm. Presumably these sites reflect the cellular localization of phorbol ester receptors and protein kinase C.

Animals↗
PubMed1985

Homogeneously staining regions (HSRs) of a rat hepatoma cell line are not early replicating.

The rat hepatoma cell line H4-IIE-C3 (H4) has homogeneously staining regions (HSRs) which contain multiple, tandemly repeated copies of ribosomal RNA (rRNA) genes. We determined the time of replication of the DNA within these HSRs autoradiographically after incorporation of [3H]thymidine and by Hoechst 33258 and Giemsa staining after 5-bromodeoxyuridine (5-BrdU) incorporation. The DNA within the H4 HSRs is not early replicating, unlike that in other HSRs. It begins replicating later than much of the other nuclear DNA, continues replicating throughout most of the S phase, and is completed 1-2 h before mitosis.

Animals↗
PubMed1984

Actinomycin D in low concentrations binds uniformly to human chromosomes.

The binding of actinomycin D (actD) to fixed human metaphase chromosomes was studied by using autoradiography with [3H]actD and indirect immunofluorescence with a specific anti-actD antibody. At concentrations of 0.01 and 0.1 micrograms/ml there was a uniform distribution of drug along the chromosomes as observed by both methods. This is the first study to date characterizing actD binding at such low concentrations to human chromosomes. Since actD intercalates into the DNA helix with GC specificity, our observations indicate that detectable differences in base composition along the lengths of human chromosomes are minimal.

Chromosomes↗
PubMed1982

Development of an antibody to actinomycin D and its application for the detection of serum levels by radioimmunoassay.

An antibody specific for actinomycin D (Act D) has been developed and used in a rapid, sensitive radioimmunoassay for detection of this anticancer drug in serum. The 2-amino group of the heterocyclic chromophore of Act D was covalently coupled to available free carboxyl groups of bovine serum albumin with carbodiimide. The resulting complex was then used for the production of a specific antibody to Act D in two male New Zealand rabbits. Antibody production was of sufficient titer in both rabbits to allow the development of a radioimmunoassay for the free drug which is rapid and sensitive enough to accurately measure 0.1 pmol of Act D. The antibody produced was characterized to be immunoglobulin G by virtue of its ability to bind to Protein A:Sepharose columns. With the use of Act-D analog, actinomine, the antibody was characterized to be specific for the pentapeptide portion of the molecule. Pharmacokinetic analysis of serial serum samples obtained from a patient who received the drug i.v. revealed a biphasic response with an alpha-serum half-life of 1.78 and a beta serum half-life of 34 min. An i.v. injection of Act D into a dog and assay of serum concentration revealed a similar biphasic response with an alpha serum half-life of 0.78 min and a beta-serum half-life of 208 min.

Animals↗
PubMedDate not supplied

Spindle cell sarcoma of the kidney with ganglionic elements (malignant ectomesenchymoma) associated with chromosomal abnormalities and a review of the literature.

PURPOSE: Malignant ectomesenchymomas are tumors that exhibit both mesenchymal and neuroectodermal elements (1). We report a case thought to represent a malignant ectomesenchymoma arising in the kidney with cytogenetic abnormalities that may provide insight into the biologic basis for this unusual tumor. METHODS: We discuss the clinical features, histopathologic findings, cytogenetics, treatment, and outcome of a child with a malignant ectomesenchymoma arising in the kidney. RESULTS: An asymptomatic 16-month-old boy had a large abdominal mass. The resected tumor contained sheets of spindled cells that expressed mesenchymal markers and cartilaginous differentiation, interspersed with clusters of ganglion cells that expressed neural markers. No blastemal or epithelial elements were demonstrated. Cytogenetic analysis of the tumor revealed a hyperdiploid count with multiple numerical and structural abnormalities, including a translocation between chromosomes 12 and 15. In addition to the surgical resection, the patient was successfully treated with adjuvant chemotherapy and local radiation therapy. CONCLUSION: This is the first report of which we are aware of an ectomesenchymoma arising within the kidney. A subset of malignant ectomesenchymomas may be related to the Ewing's family of tumors (EFTs) (2), but this case did not exhibit cytogenetic features consistent with EFT. Thus, the malignant ectomesenchymoma phenotype probably represents a heterogeneous group of tumors with different genotypes and origins. Cytogenetic analysis may be instrumental in determining the appropriate therapeutic approach when faced with such a neoplasm. The outcomes of 12 other children with ectomesenchymoma are reviewed.

Child, Preschool↗
PubMedDate not supplied

Immunohistochemical localization of actinomycin D in human melanoma tumor cells.

Human melanoma tumor colonies and derived cell lines (81-46a) were exposed to Actinomycin D (Act D) in vitro in order to study subcellular sites of drug-cell interaction. Light microscopy of 13 day-old colonies previously treated for 24 hours with 0.01 microgram/ml, 0.1 microgram/ml, and 1 microgram/ml Act D revealed a decrease in colony size and organization, an increase in pyknotic nuclei, and an accumulation of cell debris concomitant with an increase in Act D concentration. The 81-46a cells were treated with 0.1 microgram/ml Act D for 15, 30, and 60 minute intervals, followed by Act D antibodies. Immunofluorescence microscopy revealed both cytoplasmic, vesicular, filamentous, and nuclear variations in drug distribution with increased exposure. Cell viability studies indicated a decrease in viable cells as exposure time to Act D increased.

Cell Line↗