Proto cells, growth

RAO G N and berk b c (1992) Active oxygen species stimulate vascular smooth muscle cell growth and proto-oncogene expression Circulation Research 70, 593-9. 

Spritz, R. A., Holmes, S. A., Ramesar, R., Greenberg, J., Curtis, D., and Beighton, P. (1992). Mutations of the KIT (mast/stem cell growth factor receptor) proto-oncogene account for a continuous range of phenotypes in human piebaldism. Am. J. Hum. Genet. 51 1058-1065. 

Of course, the critical importance of Ras and most other small G proteins in cell growth and differentiation is highlighted by the consideration, stated above, that several forms of these proteins are proto-oncogenes (see also... 

Normal version (proto-oncogene) is usually involved in promoting cell growth/proliferation Normal version of gene is typically involved in controlling ceU proliferation (e.g., ceU cycle control, cell adhesion control)... 

Proto-oncogenes can be classified into many different groups, based upon their normal function within cells or based upon sequence homology to other known proteins. Proto-oncogenes have been identified at all levels of the various signal transduction cascades that control cell growth, proliferation and differentiation. 

In addition to its acute effects on contractile function of vascular and cardiac muscle, ET-1 influences cell growth, proliferation and migration. ET-1 stimulates DNA synthesis, as indicated by increased H-thymidine uptake [31-33], stimulates cellular Na /H exchange [33] and increases the expression of the proto-oncogenes, c-fos and c-myc [31] in vascular smooth muscle cells. ET-1 also induces cardiac gene expression [34]. 

Our main concern here is the dynamics of these molecule numbers A, of the species i in relationship with the condition of the recursive growth of the (proto)cell. In our model there are four basic parameters the total number of molecules N, the total number of molecular species k, the mutation rate p, and the reaction path rate p. By carrying out simulations of this model (choosing a variety of parameter values N, k, p, and p) and also by taking various random networks, we have found that the behaviors are classified into the following three phases [32,33] ... 

All normal cells have proto-oncogenes in their nucleus. There are at least 70 different proto-oncogenes in the cell. Such genes are considered to play an important role in the regulation of cell growth and differentiation. However, they can be activated into oncogenes, which then induce neoplastic transformation. 

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