What is overexpression of genes?
Gene overexpression is the switching on of genes in aging cells. Most of these have been demonstrated in senescent human fibroblasts and are functionally associated with the degradation of the ECM and the production of cytokines (i.e., these are deleterious functions that will lead to tissue damage).
What is amplification in gene expression?
Gene amplification refers to an increase in the number of copies of the same gene rather than to an increase in its rate of transcription. It results from gene duplication that has been repeated many times over, producing from 100 to 1000 copies of the gene.
How gene amplification can regulate gene expression?
Developmentally regulated gene amplification serves to increase the number of templates for transcription, yielding greatly increased protein and/or RNA product for gene(s) at the amplified loci. The studies indicate a regulatory role for chromatin structure and transcriptionally active genes near the origins.
Why is overexpression of genes bad?
Because overexpression of wild-type genes can cause mutant phenotypes, it has been exploited by geneticists working in tractable genetic systems as a parallel approach to loss-of-function screens.
What is gene amplification and how it occurs?
What causes overexpression of gene?
Gene overexpression or downregulation can be due to processes such as gene amplification, activating mutation, or epigenetic activation.
What is the purpose of gene amplification in gene therapy?
The presence of gene amplification can have a prognostic and a diagnostic value and can help in orienting therapy in specific tumour types. The amplified DNA is primarily produced through recombination-based pathways and can be located either within chromosomes or on extra-chromosomal acentric elements.
How is overexpression of cyclins related to gene amplification?
One of the mechanisms behind overexpression is gene amplification of the cyclins’ genes at the DNA level. However, the overexpression may also be caused at the posttranslational level. The prognostic value of cyclin overexpression may be different whether overexpression is caused by gene amplification or by impaired degradation.
How is the amplification of the MDM2 gene detected?
mdm2 gene amplification was detected in 35% of the samples by differential polymerase chain reaction, all of which overexpressed MDM2. These results suggest that the amplification and/or overexpression of mdm2 may be one of the major molecular events occurring in the tumorigenesis of ependymomas.
What is the prognostic value of cyclin overexpression?
The prognostic value of cyclin overexpression may be different whether overexpression is caused by gene amplification or by impaired degradation. This may especially be important regarding cyclin A.