Search results
Results from the WOW.Com Content Network
It has been known that centromere misregulation contributes to mis-segregation of chromosomes, which is strongly related to cancer and miscarriage. Notably, overexpression of many centromere genes have been linked to cancer malignant phenotypes. Overexpression of these centromere genes can increase genomic instability in cancers.
The CENPA protein is a histone H3 variant which replaces one or both canonical H3 histones in a subset of nucleosomes within centromeric chromatin. [ 9 ] [ 10 ] CENPA has the greatest sequence divergence of the histone H3 variants, with just 48% similarity to canonical histone H3, and has a highly diverged N-terminal tail that lacks many well ...
Mitosis appearances in breast cancer. In histopathology, the mitosis rate (mitotic count or mitotic index) is an important parameter in various types of tissue samples, for diagnosis as well as to further specify the aggressiveness of tumors. For example, there is routinely a quantification of mitotic count in breast cancer classification. [74]
A distinct type of extrachromosomal DNA, denoted as ecDNA, is commonly observed in human cancer cells. [2] [3] [4] ecDNA found in cancer cells contain one or more genes that confer a selective advantage. ecDNA are much larger than eccDNA, and are visible by light microscopy. ecDNA in cancers generally range in size from 1-3 MB and beyond. [2]
The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms. This number, along with the visual appearance of the chromosome, is known as the karyotype , [ 1 ] [ 2 ] [ 3 ] and can be found by looking at the chromosomes through a microscope .
The SWI/SNF ATPase BRG1 (or SMARCA4) is the most frequently mutated chromatin remodeling ATPase in cancer. [27] Mutations in this gene were first recognized in human cancer cell lines derived from lung. [28] In cancer, mutations in BRG1 show an unusually high preference for missense mutations that target the ATPase domain.
When the chromatin decondenses, the DNA is open to entry of molecular machinery. Fluctuations between open and closed chromatin may contribute to the discontinuity of transcription, or transcriptional bursting. Other factors are probably involved, such as the association and dissociation of transcription factor complexes with chromatin.
That neocentromeres and conventional centromeres do not share consistent chromatin environment should also be taken into account in questioning the epigenetic regulation of centromere formation. [19] The N-terminal tails of histones can be modified in several ways, including phosphorylation , acetylation , methylation and ubiquitination .