Nucleus image properties and cell death in MCF-10F cells grown on slide substrates differing in nature and size.

The immortalized human breast epithelial cell line MCF-10F is an important tool for studies on experimental tumorigenesis induced by drugs, transfected Ha-ras oncogene, and hormones. Considering that many relevant data have thus far been established only for MCF-10F cells cultivated on glass, and that there are data showing different cell death ratios for tumorigenic cells obtained from benzo[a]pyrene (BP)-transformed MCF-10F cells cultivated on plastic compared with glass, nuclear parameters estimated by image analysis and cell death ratios were compared for cells grown on plastic and glass substrates differing in chamber surface sizes and working culture medium volumes. It was concluded that for slides with a growth size equal to 9.4 cm2, plastic substrate was more advantageous than glass for growing MCF-10F cells because although the apoptotic ratios (AR) for the cells grown on plastic are low as it would be expected for nontransformed cells, they are bigger than those reported for the BP-transformed MCF-10F cells cultivated on the same substrate but closer to those of the BP-transformed MCF-10F cells receiving a normal chromosome 17. In addition, the plastic substrate did not induce variable nuclear image results as those found in the latter. The 0.5-cm2-sized chambers on plastic slides proved to be inadequate for cell nuclear image analysis and cell death studies on account of the variable geometric, densitometric, and textural results and ARs produced and the unpublished consideration of a very slow growth rate generated under this growth condition.

RNA relocation and persistence of nucleolus-like bodies at mitosis in benzo[a]pyrene-transformed human breast epithelial cells after microcell-mediated transfer of chromosomes 11 and 17.

RNA relocation and the incidence of nucleolus-like bodies accumulated during mitosis were studied cytochemically in benzo[a]pyrene (BP)-transformed human breast epithelial MCF-10F cells after microcell-mediated transfer of normal chromosomes 11 and 17. The changes resulting from the transfer of these two chromosomes in tumorigenic MCF-10F cells (BP1-E cell line) were examined, since alterations in these chromosomes are involved in the expression of the transformed and tumorigenic phenotypes in the MCF-10F cell series. In addition, the frequency of nucleolus-like bodies decreases drastically with transformation and tumorigenicity in MCF-10F cells, thus being conceivable that it would be affected in presence of normal chromosomes 11 or 17. The pattern of RNA relocation associated with the mitotic spindle did not vary in the cell lines analyzed. The introduction of chromosome 17 in BP1-E cells either decreased or did not affect the frequency of persistent nucleolus-like bodies. In contrast, in cells which received a normal chromosome 11, the frequency of nucleolus-like bodies was closer to that of non-transformed MCF-10F cells. These results suggest that a normal chromosome 11 but not chromosome 17 contributes to the maintenance of an RNA surplus which accumulates in nucleolus-like bodies during cell division of the human breast epithelial cells, at least in vitro. Some loci which were retained in the BP1-E cells which received a normal chromosome 11 are probably involved with the control of RNA transcript production. Figure 1 on http://www.esacp.org/acp/2001/23-3,4/mello.htm