Effect of steroid and serum starvation on a human breast cancer adenocarcinoma cell line.

Objective: Breast cancer is one of the most frequent cancers in women. Although there are many treatment protocols for this disease, there are still many patients who do not respond satisfactorily to the current treatment protocols. A better understanding of the nature of the tumor cells might provide a guide for better therapeutic procedures. In this study, the effect of metabolic stress was assessed on the human adenocarcinoma MCF-7 cell line. The cells were seeded in culture plates and after reaching log phase of their growth, cells were exposed to phenol red free-media supplemented with 10%, 0.5%, 0.25% and 0% charcoal-treated serum for 1 to 6 consecutive days. At 24-hour intervals, the cells' ability to proliferate (trypan blue assay), cells mitochondrial content (MTT assay) and intracellular protein content (SRB assay) was assessed. In each day of the study, the cells were released in complete media containing 10% serum for 24 hours and the effect of release was observed on cells. This study showed reduced basal growth rate and proliferation in response to harsh environmental conditions. Protein content of the cells also decreased. Mitochondrial content/activity of the cells however did not decrease, but instead a relative increase was observed at some time points. Releasing the cells caused increased cell proliferation in media with up to 0.5% serum, with an increase in intracellular protein content, although no significant mitochondrial function increase was observed. The results of this study confirm the adaptation of MCF-7 cells to environmental harsh conditions.