Chromosomal instability (CIN) refers to a higher than normal rate of missegregation of chromosomes or parts of chromosomes during mitosis due to defective cell cycle quality control mechanisms, resulting in copy number alterations (CNAs) or aneuploidy.
What causes chromosome instability?
One way that Chromosome Instability can be acquired is by exposure to ionizing radiation. Radiation is known to cause DNA damage, which can cause errors in cell replication, which may result in chromosomal instability. Chromosomal instability can in turn cause cancer.
How is chromosomal instability measured?
The number of fluorescent foci present within a cell can be used as a surrogate marker for chromosome copy numbers, and this can be monitored through multiple rounds of cell division. Thus, both population heterogeneity and the temporal dynamics of copy number gains or losses can be quantified to evaluate N-CIN.
What makes chromosomes stable and how?
Maintenance of chromosome stability involves the function of at least 723 genes in yeast (3). Each specific gene is implicated in chromosome stability because loss-of-function (4–8) or over-expression (9) of the specific gene causes chromosome instability.
What is genomic instability?
Genomic instability is a characteristic of most cancer cells. It is an increased tendency of genome alteration during cell division. Cancer frequently results from damage to multiple genes controlling cell division and tumor suppressors.
What is a microsatellite instability?
Listen to pronunciation. (MY-kroh-SA-teh-lite in-stuh-BIH-lih-tee) A change that occurs in certain cells (such as cancer cells) in which the number of repeated DNA bases in a microsatellite (a short, repeated sequence of DNA) is different from what it was when the microsatellite was inherited.
What is chromosome spread?
DNA:DNA in situ hybridization is usually carried out on chromosome spread preparations where chromosome and nuclei are released from cells and spread on a glass microscope slide. … Ideally, cells and nuclei should be spread to a single layer and there should be little or no contact between cells and nuclei.
How do you test for genomic instability?
PCR is the gold standard for detecting MSI. PCR is used to amplify known microsatellite regions, and the lengths of the short tandem repeats (PCR products) are compared in tumor and normal DNA to determine the state of MSI [37, 67, 68].
What causes loss of heterozygosity?
Loss of heterozygosity (LOH) is defined as the loss of one parent’s contribution to the cell, can be caused by direct deletion, deletion due to unbalanced rearrangements, gene conversion, mitotic recombination, or loss of a chromosome (monsomy).
What is the gain or loss of whole chromosomes?
These changes can occur during the formation of reproductive cells (eggs and sperm), in early fetal development, or in any cell after birth. A gain or loss in the number of chromosomes from the normal 46 is called aneuploidy. A common form of aneuploidy is trisomy, or the presence of an extra chromosome in cells.
Which of these provides stability chromosomes?
An important role in genomic stability is carried out by the telomeres . Telomeres are known to maintain chromosome structure and function by preventing end-to-end fusions and degradation of the chromosome ends .