[The effects of site-directed chemotherapy due to E2 as a drug carrier to the human endometrial adenocarcinoma cells in vitro].

The effects of Estracyt, a Nitrogen mustard (HN2) derivative of estradiol-17 beta versus the free HN2 on cell kinetics of the estrogen receptor positive human endometrial cancer cell line HEC-1 were investigated using flow cytometry. The results were as follows. The cell killing effects of Estracyt existed in a dependency on dose and time, whereas those of HN2 were dependent on dose alone. HN2 at 1 microgram/ml showed a marked increase in S phase and decrease in G0+1 phase. However, with equivalent doses of Estracyt at 10 micrograms/ml, even more remarkable was the accumulation in the G2+M phase. Synchronization at S phase with MTX showed no increase in sensitivity to these drugs on cells in S phase. Based on the above results, it was suggested that the free HN2 had an affect regardless of the cell cycle phase, whereas the effects of Estracyt corresponded to the cell cycle phase and Estracyt might have a fixed population of non-target cells existing in the G0+1 and S phase. Synchronization in the G1 phase with Sodium n-butylate could increase the target effects of Estracyt in S phase.