Ha-ras oncogene effect on DNA content and chromatin supraorganization in benzo[a]pyrene-transformed human breast epithelial cells.
When transfected to benzo[a]pyrene (BP)-transformed MCF-10F human breast epithelial cells (BP1 cell line) the c-Ha-ras oncogene has proven to enhance the neoplastic changes initiated by exposure to BP, giving rise to an aggressive tumorigenic cell line, BP1-Tras. We have previously demonstrated by image analysis that BP affects the DNA content and the chromatin supraorganization of MCF-10F cells. Here Feulgen-stained BP1-Tras cells were studied by image analysis in order to evaluate possible additional changes in DNA content and chromatin texture induced by insertion of the ras oncogene. A high variability in DNA content also including polyploidy or near-polyploidy, and an increase in the packing states of the chromatin which became still condensed in BP1 cells were found in BP1-Tras cells. The results differed from those reported for the BP1-E1 cell line which is also an aggressive tumorigenic cell line, but was attained through progressive passages of BP-transformed cells. It was demonstrated that different patterns of changes in DNA content and chromatin organization may be involved in equally aggressive tumorigenic BP-transformed cell lines originated from the same cell line by different mechanisms.
Mello
M L
ML
Department of Cell Biology, Institute of Biology, UNICAMP, SP, Brazil. mlsmello@obelix.unicamp.br
de Campos Vidal
B
B
Russo
J
J
D001564:Benzo(a)pyrene / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D002461:Cell Line, Transformed; D002843:Chromatin / Q000235:genetics*; D004396:Coloring Agents; D004273:DNA, Neoplasm / Q000032:analysis*; D004847:Epithelial Cells / Q000166:cytology; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D019044:Image Cytometry; D012394:Rosaniline Dyes
D002843:Chromatin; D004396:Coloring Agents; D004273:DNA, Neoplasm; C007722:Feulgen stain; D012394:Rosaniline Dyes; D001564:Benzo(a)pyrene