DNA Sequence Amplification in Mammalian Cells

Hamlin, Joyce L.; Milbrandt, Jeffrey; Heintz, Nicholas H.; Azizkhan, Jane Clifford

doi:10.1016/s0074-7696(08)61487-4

Cited by 170 publications

(67 citation statements)

References 146 publications

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“…Under certain growth conditions, the encoded gene product can provide cells with a selective growth advantage. To characterize the molecular events of gene amplification, many cultured cell lines selected for drug resistance, in which drug resistance genes are amplified, have been studied extensively (Hamlin et al, 1984;Stark and Wahl, 1984;Stark, et al, 1989;Schimke, 1988).…”

Section: Introductionmentioning

confidence: 99%

Double minute chromosomes carrying the human multidrug resistance 1 and 2 genes are generated from the dimerization of submicroscopic circular DNAs in colchicine-selected KB carcinoma cells.

Schoenlein

Shen

Barrett

et al. 1992

MBoC

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This study characterizes amplified structures carrying the human multidrug resistance (MDR) genes in colchicine-selected multidrug resistant KB cell lines and strongly supports a model of gene amplification in which small circular extrachromosomal DNA elements generated from contiguous chromosomal DNA regions multimerize to form cytologically detectable double minute chromosomes (DMs). The human MDR1 gene encodes the 170-kDa Pglycoprotein, which is a plasma membrane pump for many structurally unrelated chemotherapeutic drugs. MDR1 and its homolog, MDR2, undergo amplification when KB cells are subjected to stepwise selection in increasing concentrations of colchicine. The structure of the amplification unit at each step of drug selection was characterized using both highvoltage gel electrophoresis and pulsed-field gel electrophoresis (PFGE) techniques. An 890-kb submicroscopic extrachromosomal circular DNA element carrying the MDR1 and MDR2 genes was detected in cell line KB-ChR-8-5-1 1, the earliest step in drug selection in which conventional Southern/hybridization analyses detected MDR gene amplification. When KB-ChR-8-5-11 was subjected to stepwise increases in colchicine, this circular DNA element dimerized as detected by PFGE with and without digestion with Not 1, which linearizes the 890-kb amplicon. This dimerization process, which also occurred at the next step of colchicine selection, resulted in the formation of cytologically detectable DMs revealed by analysis of Giemsa-stained metaphase spreads.

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Section: Introductionmentioning

confidence: 99%

Double minute chromosomes carrying the human multidrug resistance 1 and 2 genes are generated from the dimerization of submicroscopic circular DNAs in colchicine-selected KB carcinoma cells.

Schoenlein

Shen

Barrett

et al. 1992

MBoC

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“…Many genes, possibly any gene, can be amplified in various organisms and, if a suitable selective agent or marker exists, amplification of a specific DNA can be identified (reviews [1][2][3]). Typical examples are amplification of drug resistance genes in the presence of cytotoxic agents [4] and of oncogenes in neoplasms [5].…”

Section: Introductionmentioning

confidence: 99%

Characterization of DNA rearrangements of N‐myc gene amplification in three neuroblastoma cell lines by pulsed‐field gel electrophoresis

Katô¹,

Okamura²,

Kurosawa³

et al. 1989

FEBS Letters

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We characterized N-myc gene amplification in three human neuroblastoma cell lines (IMR-32, TGW, GOTO). Rearrangements in long-range regions surrounding amplified N-myc genes were examined by pulsed-field gel electrophoresis. Since rare-cutting enzymes completely digested DNA at the middle of the N-myc gene, we were able to construct a physical map upstream and downstream of the germline N-myc gene, and to obtain information on restriction sites surrounding amplified N-myc genes. This method enables us to envisage the organization of amplified units over a long range. Digestion patterns differed considerably among the germline and the three cell lines, but were simple in each case. We estimated that the minimal distance between neighboring N-myc genes is at least several hundred kilobases. Our data suggest that amplification units contain several DNA fragments derived from different loci, but that they are homogeneous.

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“…Moreover, labeling of silver grains with the v-myc probe distributes randomly over the entire segment (Misawa et al, submitted). Fhe results suggest that this segment originated from band 8q24.1 which is the native site of this protooncogene (Neel et al, 1982;Taub et al, 1982), or that dmin, where the c-myc is also amplified in HL-60 cells (Misawa et aI., submitted), is integrated into band 8q24.1 at the site of sequence homology, although the integration of the extrachromosomal DNA sequences can potentially occur anywhere in the genome (Cowell, 1982;Hamlin et al, 1984). Dmin vary in size among different metaphases.…”

Section: Discussionmentioning

confidence: 98%

“…Balaban-Malenbaum and Gilbert (1980) compared the amount of DNA in HSR-containing chromosomes with that in normal homologues from the same human neuroblastoma cells, and they found that the DNA content of HSR-bearing chromosomes was 50-250~ greater. However, in a wide variety of HSR-bearing mammalian cells the length of HSR can range from barely detectable to 15-20~ of the entire condensed mitotic genome length (Hamlin et al, 1984).…”

Section: Discussionmentioning

confidence: 99%

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Determination of chromosomal area of double minute chromosomes and a homogeneously staining region in HL-60 human leukemia cells by the use of a color image analyzer

et al. 1986

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SummaryThe surface area of chromosomes was measured in two sublines of HL-60 human leukemia cells using a color image analyzer. One subline, HL-60 (drain), had double minute chromosomes (dmin) and the other line, HL-60 (HSR), showed an abnormal chromosome #8 (8q +) which contained a homogeneously staining region (HSR) within the long arm at band q24. Drain were not seen in the latter cells. The area of individual chromosomes analyzed from metaphase plates of Giemsa-stained photographic prints proved to be reasonably accurate and reproducible. Moreover, the relative area of each chromosome correlated well both with the relative length of corresponding chromosomes and the relative DNA content. The results indicate that the mean area of a single drain represents 0.16% of the total genomic area of HL-60 (dmin) cells. The average number of dmin per cell was 8.14, and the total area of all dmin in a representative cell was 1.32% of the entire genome. The 8q+ chromosome had 1.46 times the area of the normal homologous chromosome #8, and the HSR itself had 1.30% of the total chromosomal area of HL-60 (HSR) cells. Thus, perhaps coincidentally, the relative amount of DNA in the HSR in an HL-60 (HSR) cell was similar to the total found in multiple dmin in HL-60 (drain) cells.

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DNA Sequence Amplification in Mammalian Cells

Cited by 170 publications

References 146 publications

Double minute chromosomes carrying the human multidrug resistance 1 and 2 genes are generated from the dimerization of submicroscopic circular DNAs in colchicine-selected KB carcinoma cells.

Double minute chromosomes carrying the human multidrug resistance 1 and 2 genes are generated from the dimerization of submicroscopic circular DNAs in colchicine-selected KB carcinoma cells.

Characterization of DNA rearrangements of N‐myc gene amplification in three neuroblastoma cell lines by pulsed‐field gel electrophoresis

Determination of chromosomal area of double minute chromosomes and a homogeneously staining region in HL-60 human leukemia cells by the use of a color image analyzer

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