Time-continuous branching walk models of unstable gene amplification

1994 ◽  
Vol 56 (2) ◽  
pp. 337-357 ◽  
Author(s):  
Marek Kimmel ◽  
David N. Stivers
Keyword(s):  
Gene Amplification ◽  
Unstable Gene

scholarly journals Unstable amplification of two extrachromosomal elements in alpha-difluoromethylornithine-resistant Leishmania donovani.

1992 ◽  
Vol 12 (12) ◽  
pp. 5499-5507 ◽  
Author(s):  
S Hanson ◽  
S M Beverley ◽  
W Wagner ◽  
B Ullman
Keyword(s):  
Gene Amplification ◽  
Leishmania Donovani ◽  
Molecular Mechanisms ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Unstable Gene ◽  
Extrachromosomal Elements ◽  
Circular Dnas ◽  
Amplification Mechanism

We describe the first example of unstable gene amplification consisting of linear extrachromosomal DNAs in drug-resistant eukaryotic cells. alpha-Difluoromethylornithine (DFMO)-resistant Leishmania donovani with an amplified ornithine decarboxylase (ODC) gene copy number contained two new extrachromosomal DNAs, both present in 10 to 20 copies. One of these was a 140-kb linear DNA (ODC140-L) on which all of the amplified copies of the odc gene were located. The second was a 70-kb circular DNA (ODC70-C) containing an inverted repeat but lacking the odc gene. Both ODC140-L and ODC70-C were derived from a preexisting wild-type chromosome, probably by a conservative amplification mechanism. Both elements were unstable in the absence of DFMO, and their disappearance coincided with a decrease in ODC activity and an increase in DFMO growth sensitivity. These results suggest the possibility that ODC70-C may play a role in DFMO resistance. These data expand the diversity of known amplification mechanisms in eukaryotes to include the simultaneous unstable amplification of both linear and circular DNAs. Further characterization of these molecules will provide insights into the molecular mechanisms underlying gene amplification, including the ability of linear amplified DNAs to acquire telomeres and the determinants of chromosomal stability.

Time-continuous branching walk models of unstable gene amplification

1994 ◽  
Vol 56 (2) ◽  
pp. 337-357 ◽  
Author(s):  
M KIMMEL ◽  
D STIVERS
Keyword(s):  
Gene Amplification ◽  
Unstable Gene

Unstable amplification of two extrachromosomal elements in alpha-difluoromethylornithine-resistant Leishmania donovani

1992 ◽  
Vol 12 (12) ◽  
pp. 5499-5507
Author(s):  
S Hanson ◽  
S M Beverley ◽  
W Wagner ◽  
B Ullman
Keyword(s):  
Gene Amplification ◽  
Leishmania Donovani ◽  
Molecular Mechanisms ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Unstable Gene ◽  
Extrachromosomal Elements ◽  
Circular Dnas ◽  
Amplification Mechanism

We describe the first example of unstable gene amplification consisting of linear extrachromosomal DNAs in drug-resistant eukaryotic cells. alpha-Difluoromethylornithine (DFMO)-resistant Leishmania donovani with an amplified ornithine decarboxylase (ODC) gene copy number contained two new extrachromosomal DNAs, both present in 10 to 20 copies. One of these was a 140-kb linear DNA (ODC140-L) on which all of the amplified copies of the odc gene were located. The second was a 70-kb circular DNA (ODC70-C) containing an inverted repeat but lacking the odc gene. Both ODC140-L and ODC70-C were derived from a preexisting wild-type chromosome, probably by a conservative amplification mechanism. Both elements were unstable in the absence of DFMO, and their disappearance coincided with a decrease in ODC activity and an increase in DFMO growth sensitivity. These results suggest the possibility that ODC70-C may play a role in DFMO resistance. These data expand the diversity of known amplification mechanisms in eukaryotes to include the simultaneous unstable amplification of both linear and circular DNAs. Further characterization of these molecules will provide insights into the molecular mechanisms underlying gene amplification, including the ability of linear amplified DNAs to acquire telomeres and the determinants of chromosomal stability.

Reevaluation of gene amplification in medulloblastomas

2004 ◽  
Vol 216 (03) ◽  
Author(s):  
T Lenschen ◽  
J Mühlisch ◽  
H Jürgens ◽  
C Plass ◽  
D Smiraglia ◽  
...  
Keyword(s):  
Gene Amplification

HER-2 gene amplification in pancreatic cancer

2004 ◽  
Vol 42 (05) ◽  
Author(s):  
K Borka ◽  
A Kiss ◽  
A Tőkés ◽  
P Kaliszky ◽  
P Kupcsulik ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Gene Amplification ◽  
Her 2

A PILOT STUDY OF HER-2/NEU GENE AMPLIFICATION ASSESSED BY FLUORESCENCE IN SITU HYBRIDIZATION (FISH) IN GASTRIC CANCER

2014 ◽  
pp. 15-20
Author(s):  
Van Huy Tran ◽  
Thi Minh Thi Ha ◽  
Trung Nghia Van ◽  
Viet Nhan Nguyen ◽  
Phan Tuong Quynh Le ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Cancer Patients ◽  
Gene Amplification ◽  
Cancer Tissue ◽  
Tissue Samples ◽  
Her 2 ◽  
Gastric Cancer Patients

Background: HER-2/neu is a predictive biomarker for treatment of gastric cancer using trastuzumab in combination with chemotherapy. This study aimed to evaluate the status of HER-2/neu gene amplification using fluorescence in situ hybridization (FISH) in gastric cancer. Patients and methods: thirty six gastric cancer patients were assessed HER-2/neu gene amplification by FISH using PathVysionTM HER-2 DNA Probe kit (including HER-2/neu probe and CEP-17 probe) with biopsy and surgical specimens. Results: The HER-2/neu gene amplification was observed in three cases (8.3%), the HER-2/neu gene amplification rate in Lauren’s intestinal-type and diffuse-type were 11.8% and 5.2%, respectively. Conclusion: We applied successfully FISH technique with gastric cancer tissue samples. This technique could be performed as routine test in gastric cancer in order to select patients that benefit from trastuzumab in combination with chemotherapy.

Sign in / Sign up

Export Citation Format

Share Document