ELECTRON-MICROSCOPIC ANALYSIS OF THE RELATIONSHIP BETWEEN NUCLEAR MATRIX STABILITY AND CELL-DIFFERENTIATION

Two cell lines, the less differentiated CC2/CUHK2 and the more differe ntiated CC3/CUHKE3, were used to study the difference in nuclear matri x stability against DNase I digestion, The nuclear matrix was almost t otally extracted when the CC3/CUHK3 cells were digested with 100 mu g/ ml DNase 1, while that of the CC2/CUHK2 cells was still present even w hen 200 mu g/ml DNase 1 was used, It is suggested that more differenti ated cells have a less stable nuclear matrix while the less differenti ated ones have a more stable nuclear matrix, The same phenomenon was a lso abserved in normal human and rat cervical epithelia. The nuclear m atrix of the poorly differentiated basal cells was more stable than th at of the more differentiated superficial cells. This cell differentia tion stage dependent stability of the nuclear matrix is probably relat ed to the nuclear activity and gene expression.