Telomerase, Cell Immortality, and Cancer
This extract was created in the absence of an abstract.
Excerpt
An important hallmark of cancer is aberrant growth control. Genetic changes that confer a growth advantage to the tumor cell are observed on numerous levels. Some of the best understood are mutations in proto-oncogenes and tumor suppressor genes that are linked to signal transduction pathways, cell cycle control, or cell-cell/cell-matrix interactions that regulate growth, movement, differentiation, survival, apoptosis, and genetic stability (Hartwell 1992; Weinberg 1992; Hunter 1993; Runger et al. 1994; Workman 1994). However, in addition to aberrant growth control, many cancer cells possess another important feature which distinguishes them from normal somatic cells: unlimited replicative capacity.
Hayflick first described the limited replicative capacity of normal human fibroblasts more than 30 years ago (for review, see Hayflick 1965; Goldstein 1990). Since then, numerous other somatic cell types, including epithelial cells, endothelial cells, myoblasts, astrocytes, and lymphocytes, have also shown evidence of a mitotic clock which limits their division capacity (Stanulis...
