Characteristic features of proliferation and differentiation of cambial and daughter cells in morphofunctional zones in normal epithelium and cancer in age aspect

Abstract

Work of cambial cells of normal epithelium occurs in morphofunctional zone consisting of two subunits with 12 cells in each. 12 pairs of maternal and daughter cells which have turned out at their division, create the electric field making a differentiation of daughter cells. But it is necessary to relax the cortex of epidermal daughter cells by expression of the SH3 domain of Src-kinase in them with the help of dermal cells that leads to depression of RhoA activity in epidermal cells and the further activation of the SH2 domain of Src in them responsible for a differentiation. With the years, the number of epidermal cambial cells falls from 12 in 20 years to 7 in 75+ in consequence of depression of influence of dermal cells on cambial epidermal cells, which results in dropping of expression of SH2 domain and change of a differentiation of epidermal daughter cells. The reduction of the number of cambial cells to threshold size (6) leads to sharp falling of expression of SH2 domain of Src in daughter cells. This involves augmentation RhoA in relation to Src, falling of formation of stresses-fibrils, microtubules. The stretching of nucleus is sharply decreased, which conducts to formation of incomplete loops of chromosomes, simultaneously nearby a centromere and telomere, thus the cell gets features of an epitheliocyte and a fibroblast, the transcription of proteins is broken, and the daughter epithelial cell becomes malignant.