Dinucleotide repeat polymorphism adjacent to CDKN2.
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Base Sequence↗
Biomedical subjects
K C Arden
Publications and source records attributed to K C Arden.
The RAP1GA1 locus for human Rap1-GTPase activating protein 1 maps to chromosome 1p36.1-->p35.
Using a panel of somatic cell hybrids we have mapped the locus for Rap1-GTPase activating protein 1 (RAP1GA1) to human chromosome 1. Fluorescence in situ hybridization experiments independently confirmed the chromosomal localization and refined it to 1p36.1-->p35.
Animals↗
Mutation and expression of the p53 gene in malignant melanoma cell lines.
Three monoclonal antibodies (MAbs) against p53 protein (PAb 24o, DO-I and PAb1801) were used to define the immunophenotype of 13 melanoma cell lines. Immunoreactions could be detected in 12 out of 13 cell lines by using the indirect immunofluorescence technique. In 7 of these the majority of cells displayed cytoplasmic staining whereas positive nuclei were detected in only a few cells. Two cell lines had predominantly nuclear reactivity, while the remaining 3 cell lines showed signals in both locations. Despite identical nuclear staining patterns, the 3 MAbs produced qualitatively distinct cytoplasmic immunoreactions. PAb240 and DO-1, which showed similar staining frequencies, appeared more sensitive in the detection of p53 protein than did PAb1801. Immunoprecipitations of lysates from each of the cell lines, with MAbs DO-1 and 1801 (which bind to both wild-type and mutant p53 species) detected 53-kDa proteins, whereas PAb240 (which recognizes the mutant conformation of the protein in this type of assay) detected 53-kDa proteins in only 4 cell lines. Nucleotide sequencing of exons 5 to 9 of TP53 in these latter cell lines showed that each has homozygous point mutations in the locus, whereas in the others no TP53 alterations were found. Three of the 4 mutations were C-to-T transversions, alterations possibly caused by damage from UV-light. Our findings indicate that immunostaining with p53 antibodies, although common in malignant melanoma, results from the presence of mutant p53 protein in about 30% of the cases tested. Neither immunostaining with PAb240 nor the patterns of intracellular distributions of the signals are sufficient to detect TP53 mutations.
Antibodies, Monoclonal↗
The receptors for prolactin and growth hormone are localized in the same region of human chromosome 5.
Prolactin receptor (PRLR) and growth hormone receptor (GHR) are encoded by members of a gene family containing regions of identical sequences. To determine their chromosomal locations, cDNA probes for these genes were used. Analysis of hybridization to several somatic cell hybrids, together with hybridization in situ to metaphase chromosomes, resulted in the assignment of the loci for both receptors to human chromosome 5 in the region p13----p14. Thus, these proteins may be encoded by a cluster of related genes that evolved from a common ancestral gene, in a manner consonant with that of their ligands.
Blotting, Southern↗
[Various activities of the nucleolus organizer region in normal and leukemic bone marrow cells: semiquantitative data and computer- assisted image analysis by silver staining].
A cytochemical technique with silver nitrate staining was used to study the nucleolar organizer activity in metaphase spread of bone marrow cells from 13 patients with acute lymphocytic leukemia (ALL), 11 patients with chronic myelogenous leukemia (CML), 7 patients with acute myelogenous leukemia (AML), and 4 normal persons. Additionally, computer-assisted image analysis was used to quantitate the amount of silver staining in interphase nuclei of bone marrow cells from 6 untreated ALL patients, 3 normal subjects and 1 bone-marrow-transplant recipient. The results obtained have indicated that the nucleolar organizer reactivity (NOR) is significantly lower in the control group than that in ALL patients. NOR activity level is significantly lower in both CML patients in chronic phase, and AML patients than in the ALL group, and is similar to that in the control group. When the data obtained for the interphase nuclei were compared with those obtained for the metaphase spread, a strong correlation was recorded between the fraction of bone-marrow metaphases stained positively with silver, the average number of silver-positive nucleolar organizer regions per metaphase, and the amount of silver staining in the interphase nuclei. Silver staining used for the detection of these disease-related differences in NOR activity can serve as a diagnostic procedure in evaluating human leukemias. The computer-assisted image analysis of bone marrow cell interphase nuclei would be useful for more accurate resolving biological and medical problems.
Bone Marrow↗
Computer-assisted image analysis of silver staining in normal and leukemic bone marrow.
Computer-assisted image analysis was used to quantitate the amount of silver staining in interphase nuclei of bone marrow cells from acute lymphocytic leukemia (ALL) patients. When we compared the data obtained for the interphase nuclei with that obtained for the metaphase spreads, we found a strong correlation between the fraction of bone-marrow metaphases stained positively with silver, the average number of silver-positive nucleolus organizer regions per metaphase, and the amount of silver staining in the interphase nuclei. Computer-assisted image analysis of interphase nuclei can be used, therefore, to differentiate normal from ALL bone-marrow samples.
Bone Marrow↗
Differential nucleolus organizer activity in normal and leukemic bone marrow.
A cytochemical technique that uses silver nitrate staining has been used to study the nucleolus organizer activity in bone marrow cells from 13 patients with acute lymphocytic leukemia (ALL), 11 patients with chronic myelogenous leukemia (CML), 7 patients with acute myelogenous leukemia (AML), and 4 healthy persons. Our results indicate that the nucleolus organizer region (NOR) activity was significantly lower in the control group than in the ALL patients. The NOR activity level was significantly lower in both the CML patients in chronic phase and the AML patients than in the ALL group and similar to the control group. These disease-related differences in NOR activity as detected by silver staining can be used as diagnostic procedure in evaluating human leukemias.
Bone Marrow↗
Differential silver-positive nucleolus organizer region activity in normal and malignant murine tissues.
Transcriptionally active nucleolus organizer regions (NORs) were analyzed using a silver-staining technique. The levels of silver-positive NOR activity for normal murine bone marrow and thymus cells were established, and significant differences in ribosomal RNA gene activity were observed. When tumor cells originating from these two tissue types were also studied, significant differences were seen not only between the normal and malignant tissues, but between the two tumor types as well. These differences in ribosomal RNA gene activity with respect to cell type and malignancy may be useful diagnostically.
Animals↗
Ag-NOR staining in human chromosomes: differential staining in normal and leukemic bone-marrow samples.
A silver staining technique developed by Goodpasture and Bloom (1975) stains a specific protein associated with the activity of ribosomal cistrons during the preceding interphase. By counting the number of chromosomes with darkly stained nucleolus organizer regions (NORs), the number of active NORs per metaphase can be determined. A comparison of NOR activity in bone-marrow cells from leukemic patients in different stages of disease with that of bone marrow from normal, healthy individuals was conducted and differential NOR activity was detected. The control group showed significantly lower NOR activity when compared with a group of patients with acute lymphocytic leukemia (ALL). These preliminary data indicate that this simple cytochemical technique can be effectively used to differentiate between normal and ALL bone-marrow samples.
Bone Marrow↗
Cytogenetic characterization and DNA content analysis of Ad 2-transformed rat embryo brain cells.
An adenovirus type 2-transformed rat embryo brain cell line (F 17 A2AS) and two of its subclones (F 17 CI, F 17 C2) have been studied using chromosome banding and flow cytometric techniques. In determining the modal chromosome number, a bimodal distribution was observed in each of the cell lines. In each case the first numerical mode fell in the hypertriploid or hypotetraploid range while the second represented a mode in the hypertetraploid range. Analysis of Giemsa-banded karyotypes revealed the presence of several marker chromosomes. In most cases the origins of the markers could be established from their characteristics Giemsa-banding patterns. In particular, chromosome 2 was involved in the formation of several marker chromosomes. The DNA content analysis confirmed the bimodal chromosome distribution with values in the near tetraploid and near pentaploid range for each cell line.
Adenoviridae↗