1984 Chapters (Layout Features)

Mechanisms of neoplastic transformation at the cellular level

Pollack, Robert

A major question in biology today is: What are the differences in behavior between normal cells and cells that either come from or can become tumors? A partial answer is forthcoming from somatic tissue cells grown in dishes and flasks. Even this success may be surprising, since cell cultures contain an element of artifact: insofar as they are growing, often at lower densities than found in vivo, they may be intentionally different from the cells in the tissue they mimic. In the adult body, many cells are not growing; rather, they are sitting in a matrix of other cells and their mutually secreted products in assemblies called tissues. A typical tissue has epithelia and mesodermal and fibroblast cells separated by an acellular basement membrane. The epithelial side is the topologic outside of the tissue. All epithelial cells are in contact with either neighboring cells or a collagen-based matrix. Blood vessels are on the mesodermal side, along with a nondividing cell called the fibroblast. Fibroblasts normally are quiescent.