What is meant by clonal evolution of cancer?
What is meant by clonal evolution of cancer?
Clonal evolution involves the interplay of selectively advantageous or ‘driver’ lesions, selectively neutral or ‘passenger’ lesions, and deleterious lesions, as well as lesions that increase the rate of other genetic changes (‘mutator’ lesions)13,14, and changes to the micro-environment15 that change the fitness …
What is clonal selection in cancer?
Table 1
| Burnet’s Clonal Selection Theory | Tumor Evolution Theory |
|---|---|
| Focuses on the functions of lymphocytes, specifically their response to antigens that attack the body | Focuses on the significance of natural selection in the development of cancers |
What is the role of treatment in cancer clonal evolution?
When tumor cells escape natural defense mechanisms and grow uncontrolled, the ensuing expansion processes can be countered by specific drug treatments. In this context, clonal evolution plays an important role determining tumor responses to treatment.
What is a clonal mutation?
Mutations that appear clonal across a tumour are those mutations present in all taken samples.
What is meant by clonal expansion?
Definition. The proliferation of B-lymphocytes and T-lymphocytes activated by clonal selection in order to produce a clone of identical cells. This enables the body to have sufficient numbers of antigen-specific lymphocytes to mount an effective immune response.
What is meant by clonal?
(klōn) 1. A group of cells or organisms that are descended from and genetically identical to a single progenitor, such as a bacterial colony whose members arose from a single original cell.
What is meant by the clonal selection hypothesis?
Key Terms. clonal selection: An hypothesis which states that an individual lymphocyte (specifically, a B cell) expresses receptors specific to the distinct antigen, determined before the antibody ever encounters the antigen. Binding of Ag to a cell activates the cell, causing a proliferation of clone daughter cells.
What does clonal population mean?
When cells divide by mitosis two genetically identical, therefore clonal, daughter cells are produced. Cells in a person’s body are usually clonal (as they arose from a single cell) and populations of bacteria and viruses are also often clonal.
What is clonal expansion and selection?
What is clonal expansion so important?
Clonal expansion of lymphocytes is a hallmark of vertebrate adaptive immunity. A small number of precursor cells that recognize a specific antigen proliferate into expanded clones, differentiate and acquire various effector and memory phenotypes, which promote effective immune responses.
What does clonal expansion mean?
What is the difference between clonal selection and clonal expansion?
Clonal selection is the theory that specific antigen receptors exist on lymphocytes before they are presented with an antigen due to random mutations during initial maturation and proliferation. After antigen presentation, selected lymphocytes undergo clonal expansion because they have the needed antigen receptor.
What is punctuated copy number evolution (pcne)?
An alternative model is punctuated copy number evolution (PCNE), in which CNAs are acquired in short bursts of crisis, followed by stable clonal expansions that form the tumor mass ( Supplementary Fig. 1 ).
What is clonal evolution and how does it work?
Clonal evolution involves the interplay of selectively advantageous or ‘driver’ lesions, selectively neutral or ‘passenger’ lesions, and deleterious lesions, as well as lesions that increase the rate of other genetic changes (‘mutator’ lesions), and changes to the micro-environment that change the fitness effects of those lesions.
What is somatic/clonal evolution?
Clonal evolution models of tumor heterogeneity Somatic/clonal evolution is the process of sequential acquisition of vertically transmittable genetic/epigenetic elements in multicellular organisms. Cancer is the result of somatic evolution.
How long does it take for a clonal expansion to occur?
For the initial clonal expansion to occur premalignant clones need to have a relative fitness advantage over their competitors. It is estimated that the premalignant phase can take several years.
