Amplification, gene

A diagnostic method using fluorescence labeled DNA probes to detect and quantify the number complementary chromosomal sequences on a cellular resolution. A related technique that also allows assessment of gene amplifications, but without precise quantification of copy numbers is the chromogenic in situ hybridization (CISH). Here, instead of a fluorescent dye an enzyme that can generate a colored precipitate in the tissue samples is coupled to the DNA probe. 

Figure 39-18. Schematic representation of the amplification of chorion protein genes s36 and s38. (Reproduced, with permission, from Chisholm R Gene amplification during development. Trends Biochem Sci 1982,7 161.)...

Keil H, PA Williams (1985) A new class of TOL plasmid deletion mutants in Pseudomonas putida MT15 and their reversion by tandem gene amplification. J Gen Microbiol 131 1023-1033. 

Lucke-Huhle C, Pech M, Herrlich P. 1986. Selective gene amplification in mammalian cells after exposure to 60Co J rays 241Am a particles, or UV light. Radiat Res 106 345-355. 

Thymidylate synthase (TS) is the rate-limiting enzyme in the DNA synthetic pathway and the target for 5-FU and folate analogs (Figure 14.3). Compared to normal tissues, TS is often overexpressed in tumor cells, probably as a result of tumor suppression loss of function, gene amplification or other mechanisms. Acute induction of TS protein as well as stable amplification of TS-specific genes may be associated with resistance to fluoropyrimidine derivatives [118, 119], and an inverse correlation between tumor TS expression and clinical response was found [120-122]. 

Berger SH, Jenh CH, Johnson LF et al. Thymidylate synthase overproduction and gene amplification in fluorodeoxyuri-dine-resistant human cells. Mol Pharmacol 1985 28 461—467. 

Konecny G,Thomssen C, Luck H, et al. Her-2/neu gene amplification and response to paclitaxel in patients with metastatic breast cancer. J. Natl. Cancer Inst. 2004 96 1141-1151. 

Lucke-Huhle, C., B. Gloss, and P. Herrlich. 1990. Radiation-induced gene amplification in rodent and human cells. Acta Biol. Hungarica 41 159-171. 

Carboxylesterases are well-represented in insects and are sometimes important in the development of resistance to insecticides. Thus, a well-characterized carboxylesterase E4 is responsible for resistance to organophosphorus insecticides in the aphid (Myzuspersicae) [107]. In the California Culex mosquito, the esterase B1 is 500-fold more abundant in organophosphate-resistant than in susceptible insects. The increase of esterase levels is the result of gene amplification, i.e., the resistant animals have an increased number of copies of the structural esterase gene [108],... 

In mouse cerebellum and cerebral cortex by IHC and WB (Zehnder et al, 2001). Gene amplification for 25-hydroxyvitamin D(3) 1,alpha-hydroxylase and nonfunctional mRNA splice variants in human glioblastoma multiforme (Maas et al, 2001 Diesel et al, 2004, 2005). 

Gene amplification 1 Many oncogenes are present in multiple copies erbB amplified in certain breast cancers Dihydrofolate reductase genes are amplified in some tumors, leading to drug resistance... 

Allen, J. D., Biinkhuis, R. F., Wijnholds, J., and Schinkel, A. H. (1999) The mouse Bcrpl/ Mxr/Abcp gene amplification and overexpression in cell lines selected for resistance to topo-tecan, mitoxantrone, or doxorubicin. Cancer Res. 59, 4237-4241. 

Augmented drug extrusion increased synthesis of the P-glycoprotein that extrudes drugs from the cell (e.g., anthracyclines, vinca alkaloids, epipodophyllotoxins, and paclitaxel) is re-ponsible for multi-drug resistance (mdr-1 gene amplification). 

Schimke RT (1986) Methotrexate resistance and gene amplification. Mechanisms and implications. Cancer 57 1912-1917... 

Bright-Field In Situ Hybridization Methods to Discover Gene Amplifications and Rearrangements in Clinical Samples... 

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