Effects of gossypol on the cell cycle phases in T-47D human breast cancer cells.

Since gossypol, a naturally occurring component of cottonseed oil, exhibits a broad spectrum of activities, we have examined it as an antitumor agent on breast cancer. The effects of different concentrations of gossypol on the T-47D human breast cancer cell cycle phases were studied using cytometric image processing on Feulgen stained nuclei. The proportion of cells at different cell cycle phases was determined by discriminate analysis of the image parameters and gave good classification ranging from 86 to 100%. Gossypol was found to increase the G0/G1 fraction of the T-47D cells. This cell kinetic alteration by gossypol was shown to be dose dependent and reversible. Complete reversal of the effect of gossypol was observed after four days with a simple change to gossypol-free medium. The cells then progressed into S and G2/M phase, thus indicating that gossypol-treated cells remain viable. Gossypol was shown to have a strong inhibitory effect on cellular proliferation in T-47D cells. It was also found that this agent is only toxic to cells at the highest dose tested (10 microM). The results of this study may be of clinical significance in the treatment of breast cancer, since gossypol shows strong antiproliferative properties.