J. Grabbe et al., STEM-CELL FACTOR, A NOVEL CUTANEOUS GROWTH-FACTOR FOR MAST-CELLS AND MELANOCYTES, Archives of dermatological research, 287(1), 1994, pp. 78-84
Mechanisms affecting mast cell and melanocyte growth and function are
still poorly understood. This report summarizes the current state of k
nowledge on a recently described growth factor for both these cell typ
es and for primitive haematopoietic stem cells. Stem cell factor (SCF)
, also named mast cell growth factor or kit-ligand, has only recently
been cloned and has been shown to be encoded on human chromosome 12. I
t may be of specific importance in cutaneous physiology and pathology
since it is produced by several cell types in the skin (e.g. fibroblas
ts, keratinocytes, endothelial cells) and since it affects melanocyte
and mast cell growth, survival, secretion and adhesion as well as migr
ation into tissues. Defects in the genes encoding for the SCF receptor
(c-kit-protein) have been shown to be responsible for human piebaldis
m. A pathogenetic role in mastocytosis has recently been proposed, but
remains to be proven. SCF receptor expression is decreased on cells o
f some malignant cell lines compared to their physiological counterpar
ts, making it unlikely that SCF is a key factor in malignant transform
ation and cellular hyperproliferation. In haematopoiesis, SCF acts pri
marily in concert with other growth factors, and we show here that alo
ne in serum-free culture it has no effect on mast cell growth. Further
more, there is evidence that besides SCF, additional mast cell growth
factors are secreted by fibroblasts and keratinocytes, suggesting a co
mplex orchestration of several growth factors in the regulation of cut
aneous growth and differentiation in which SCF plays only one part.