DNA content, chromatin texture and nuclear morphology in benzo[a]pyrene-transformed human breast epithelial cells after microcell-mediated transfer of chromosomes 11 and 17.

BACKGROUND

A relation between the changes in DNA content and chromatin supra-organization and the expression of gradual steps of tumorigenesis has been assessed by image analysis in human breast epithelial cells (MCF-10F) treated with benzo[a]pyrene (BP) (cell lines BP1, BP1-E, BP1-Tras, and others).

METHODS

Because abnormal chromosomes 11 and 17 have been associated with neoplastic progression in BP-transformed MCF-10F cells, image analysis of Feulgen-stained tumorigenic BP1-E cells with the microcell-mediated chromosome transfer of normal chromosomes 11 and 17 was carried out.

RESULTS

A tendency of DNA amount distribution and nuclear size restoration to values typical of non-transformed MCF-10F cells was demonstrated, especially after the transfer of chromosome 17. No reversion in chromatin texture was found after the transfer of chromosome 11 or 17.

CONCLUSIONS

Although the presence of a normal chromosome 17 should be considered among the necessary steps for tumorigenic human breast epithelial cells to recover their normality, a more complex genome balance is required for the entire nuclear chromatin of these cells to recover its totally normal supra-organization and expression.