Cell proliferation is the process by which ''a cell grows and divides to produce two daughter cells''.
Cell proliferation leads to an
exponential increase in cell number and is therefore a rapid mechanism of
tissue growth
Tissue growth is the process by which ''a tissue increases its size''. In animals, tissue growth occurs during embryonic development, post-natal growth, and tissue regeneration. The fundamental cellular basis for tissue growth is the process ...
. Cell proliferation requires both
cell growth
Cell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. Cell growth occurs when the overall rate of cellular biosynthesis (production of biomolecules or anabolism) is greater th ...
and
cell division
Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there ...
to occur at the same time, such that the average size of cells remains constant in the population. Cell division can occur without cell growth, producing many progressively smaller cells (as in
cleavage of the zygote), while cell growth can occur without cell division to produce a single larger cell (as in growth of
neurons). Thus, cell proliferation is not synonymous with either cell growth or cell division, despite the fact that these terms are sometimes used interchangeably.
Stem cells undergo cell proliferation to produce proliferating "transit amplifying" daughter cells that later
differentiate to construct
tissues during normal
development and tissue growth, during
tissue regeneration
In biology, regeneration is the process of renewal, restoration, and tissue growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Every species is capable of ...
after
damage, or in
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
.
The total number of cells in a population is determined by the rate of cell proliferation minus the rate of
cell death.
Cell size depends on both cell growth and cell division, with a disproportionate increase in the rate of cell growth leading to production of larger cells and a disproportionate increase in the rate of cell division leading to production of many smaller cells. Cell proliferation typically involves balanced cell growth and cell division rates that maintain a roughly constant cell size in the exponentially proliferating population of cells. Cell proliferation occurs by combining cell growth with regular "G1-
S-
M-G2"
cell cycle
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and sub ...
s to produce many
diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectiv ...
cell progeny.
In single-celled organisms, cell proliferation is largely responsive to the availability of
nutrients
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excr ...
in the environment (or laboratory
growth medium).
In
multicellular
A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism.
All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially ...
organisms, the process of cell proliferation is tightly controlled by
gene regulatory networks encoded in the
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...
and executed mainly by
transcription factors including those regulated by
signal transduction pathways elicited by
growth factors during
cellcell communication in
development. Recently it has been also demonstrated that cellular bicarbonate metabolism, which is responsible for cell proliferation, can be regulated by mTORC1 signaling.
[ In addition, intake of ]nutrients
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excr ...
in animals can induce circulating hormones of the Insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism ...
/ IGF-1 family, which are also considered growth factors, and that function to promote cell proliferation in cells throughout the body that are capable of doing so.
Uncontrolled cell proliferation, leading to an increased proliferation rate, or a failure of cells to arrest their proliferation at the normal time, is a cause of cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
.
References
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Cellular processes