scholarly journals Variation in topoisomerase I gene copy number as a mechanism for intrinsic drug sensitivity

1996 ◽  
Vol 74 (4) ◽  
pp. 508-512 ◽  
Author(s):  
HL McLeod ◽  
WN Keith
Keyword(s):  
Copy Number ◽  
Topoisomerase I ◽  
Drug Sensitivity ◽  
Gene Copy Number ◽  
Gene Copy ◽  
I Gene

Assessment of the topoisomerase I gene copy number as a predictive biomarker of objective response to irinotecan in metastatic colorectal cancer

2013 ◽  
Vol 49 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Sune Boris Nygård ◽  
Ib Jarle Christensen ◽  
Signe Lykke Nielsen ◽  
Hans Jørgen Nielsen ◽  
Nils Brünner ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Metastatic Colorectal Cancer ◽  
Copy Number ◽  
Topoisomerase I ◽  
Objective Response ◽  
Gene Copy Number ◽  
Predictive Biomarker ◽  
Gene Copy ◽  
I Gene

scholarly journals DNA Topoisomerase I Gene Copy Number and mRNA Expression Assessed as Predictive Biomarkers for Adjuvant Irinotecan in Stage II/III Colon Cancer

2015 ◽  
Vol 22 (7) ◽  
pp. 1621-1631 ◽  
Author(s):  
Sune Boris Nygård ◽  
Ben Vainer ◽  
Signe Lykke Nielsen ◽  
Fred Bosman ◽  
Sabine Tejpar ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Mrna Expression ◽  
Copy Number ◽  
Topoisomerase I ◽  
Gene Copy Number ◽  
Predictive Biomarkers ◽  
Gene Copy ◽  
Dna Topoisomerase I ◽  
Dna Topoisomerase ◽  
I Gene

Competitive Polymerase Chain Reaction for the Quantification of N-myc Gene Copy Number in Neuroblastoma

Tumor Biology ◽  
1996 ◽  
Vol 17 (5) ◽  
pp. 262-270 ◽  
Author(s):  
Akira Inoue ◽  
Ziaul Hasan ◽  
Hiromichi Hemmi ◽  
Naotoshi Kanda ◽  
Yasuhide Hayashi ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Copy Number ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Chain Reaction ◽  
Competitive Polymerase Chain Reaction ◽  
Polymerase Chain ◽  
I Gene

scholarly journals Mechanisms of Topoisomerase I (TOP1) Gene Copy Number Increase in a Stage III Colorectal Cancer Patient Cohort

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e60613 ◽  
Author(s):  
David Hersi Smith ◽  
Ib Jarle Christensen ◽  
Niels Frank Jensen ◽  
Bo Markussen ◽  
Maria Unni Rømer ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Patient ◽  
Copy Number ◽  
Topoisomerase I ◽  
Colorectal Cancer Patient ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Patient Cohort ◽  
Number Increase ◽  
Copy Number Increase

scholarly journals Estimating Copy-Number Proportions: The Comeback of Sanger Sequencing

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 283
Author(s):  
Eyal Seroussi
Keyword(s):  
Copy Number ◽  
Sanger Sequencing ◽  
Cytosine Methylation ◽  
Direct Sequencing ◽  
Information Source ◽  
Gene Copy Number ◽  
Cost Effective ◽  
Gene Copy ◽  
Base Editing ◽  
Recent Developments

Determination of the relative copy numbers of mixed molecular species in nucleic acid samples is often the objective of biological experiments, including Single-Nucleotide Polymorphism (SNP), indel and gene copy-number characterization, and quantification of CRISPR-Cas9 base editing, cytosine methylation, and RNA editing. Standard dye-terminator chromatograms are a widely accessible, cost-effective information source from which copy-number proportions can be inferred. However, the rate of incorporation of dye terminators is dependent on the dye type, the adjacent sequence string, and the secondary structure of the sequenced strand. These variable rates complicate inferences and have driven scientists to resort to complex and costly quantification methods. Because these complex methods introduce their own biases, researchers are rethinking whether rectifying distortions in sequencing trace files and using direct sequencing for quantification will enable comparable accurate assessment. Indeed, recent developments in software tools (e.g., TIDE, ICE, EditR, BEEP and BEAT) indicate that quantification based on direct Sanger sequencing is gaining in scientific acceptance. This commentary reviews the common obstacles in quantification and the latest insights and developments relevant to estimating copy-number proportions based on direct Sanger sequencing, concluding that bidirectional sequencing and sophisticated base calling are the keys to identifying and avoiding sequence distortions.

scholarly journals Nongenotoxic ABCB1 activator tetraphenylphosphonium can contribute to doxorubicin resistance in MX-1 breast cancer cell line

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raimonda Kubiliute ◽  
Indre Januskeviciene ◽  
Ruta Urbanaviciute ◽  
Kristina Daniunaite ◽  
Monika Drobniene ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Line ◽  
Protein Level ◽  
Copy Number ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Common Mechanism ◽  
Dna Hypomethylation ◽  
Mesenchymal Transition ◽  
Molecular Features

AbstractHyperactivation of ABC transporter ABCB1 and induction of epithelial–mesenchymal transition (EMT) are the most common mechanism of acquired cancer chemoresistance. This study describes possible mechanisms, that might contribute to upregulation of ABCB1 and synergistically boost the acquisition of doxorubicin (DOX) resistance in breast cancer MX-1 cell line. DOX resistance in MX-1 cell line was induced by a stepwise increase of drug concentration or by pretreatment of cells with an ABCB1 transporter activator tetraphenylphosphonium (TPP+) followed by DOX exposure. Transcriptome analysis of derived cells was performed by human gene expression microarrays and by quantitative PCR. Genetic and epigenetic mechanisms of ABCB1 regulation were evaluated by pyrosequencing and gene copy number variation analysis. Gradual activation of canonical EMT transcription factors with later activation of ABCB1 at the transcript level was observed in DOX-only treated cells, while TPP+ exposure induced considerable activation of ABCB1 at both, mRNA and protein level. The changes in ABCB1 mRNA and protein level were related to the promoter DNA hypomethylation and the increase in gene copy number. ABCB1-active cells were highly resistant to DOX and showed morphological and molecular features of EMT. The study suggests that nongenotoxic ABCB1 inducer can possibly accelerate development of DOX resistance.

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