Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 262

Asymmetric cell division is an essential cellular mechanism that allows an organism to maintain a sufficient number of cells of each type. In C. elegans, asymmetric cell division allows the production of two daughter cells that have the potential to proceed toward their own distinct path. One cell fate for nematode stem cells involves the distal tip, which is a region that consists of cells that constantly divide, thus generating more cells in its pool. The other cell fate is that of the differentiating cell and progresses into a specific germ cell that determines the sex of the organism.

Other than its role in development, asymmetric cell division has also been associated with the production of cancer stem cells. Previous studies have suggested that tumors might have arisen from a subpopulation of stem cells that are capable of self-renewal. This incessant expansion of cells is a hallmark of both normal stem cells and cancer cells and thus it is possible that the same mechanism of asymmetric cell division could be pursued for the control of cancer progression. The detailed events of asymmetric cell division may also be used as targets of novel pharmaceutical products that aim to prevent the further proliferation of cancer stem cells. Current studies are investigating various extracellular and intracellular signals that regulate the processes of self-renewal and differentiation of stem cells in C. elegans, with the hope of gathering more information on the components and steps involved in each mechanism.

The activities of self-renewal and proliferation are key features that are tightly controlled by various external and internal signals, which vary according to their effective distance, wherein some signals are directly secreted onto the target protein whereas others can elicit a response despite their location from a distal region of the body. C. elegans has served as a highly useful animal model to study the mechanisms behind the survival and maintenance of stem cells. Although it presents similarities with other model organisms, it also possesses unique features that are still useful in the elucidation of tissue homeostasis.

Rhea U. Vallente

Independent Scholar

See Also: Adult Stem Cells: Overview; Cancer Stem Cells: Overview; Stem Cell Niche.