TY - JOUR

T1 - Endocrine sensitivity of the receptor-positive T61 human breast carcinoma serially grown in nude mice

AU - Brünner, N

AU - Spang-Thomsen, M

AU - Skovgaard Poulsen, H

AU - Engelholm, S A

AU - Nielsen, A

AU - Vindeløv, L

N1 - Keywords: Animals; Breast Neoplasms; Castration; Cell Division; Cell Line; DNA; Estradiol; Female; Flow Cytometry; Humans; Male; Mice; Mice, Nude; Middle Aged; Receptors, Estrogen; Receptors, Progesterone; Tamoxifen; Time Factors

PY - 1985

Y1 - 1985

N2 - A study was made on the effect of ovariectomy, 17 beta-oestradiol, and tamoxifen on the oestrogen and progesterone receptor-positive T61 human breast carcinoma grown in nude mice. The effect of the treatment was evaluated by the specific growth delay calculated on the basis of Gompertz growth curves, and by the changes in the cell cycle distribution monitored by flow cytometric DNA analysis. The results demonstrated that both oestradiol and tamoxifen induced a temporary growth delay, whereas ovariectomy of the host had no effect on the growth of the tumour. The oestradiol-induced tumour growth delay was accompanied by a decrease in the G1 fraction, an accumulation of cells in the S-phase, and polyploidy, whereas neither treatment with tamoxifen nor ovariectomy influenced cell cycle distribution. The results indicate that oestradiol and tamoxifen have different mechanisms of action. In addition, they were interpreted as indicating different mechanisms regulating ovarian-dependent tumour growth, on the one hand, and oestrogen and tamoxifen-induced tumour growth inhibition, on the other. The results support the view that the presence of receptors may be of importance but is not a sufficiently clear marker to allow prediction of the endocrine sensitivity of individual breast tumours.

AB - A study was made on the effect of ovariectomy, 17 beta-oestradiol, and tamoxifen on the oestrogen and progesterone receptor-positive T61 human breast carcinoma grown in nude mice. The effect of the treatment was evaluated by the specific growth delay calculated on the basis of Gompertz growth curves, and by the changes in the cell cycle distribution monitored by flow cytometric DNA analysis. The results demonstrated that both oestradiol and tamoxifen induced a temporary growth delay, whereas ovariectomy of the host had no effect on the growth of the tumour. The oestradiol-induced tumour growth delay was accompanied by a decrease in the G1 fraction, an accumulation of cells in the S-phase, and polyploidy, whereas neither treatment with tamoxifen nor ovariectomy influenced cell cycle distribution. The results indicate that oestradiol and tamoxifen have different mechanisms of action. In addition, they were interpreted as indicating different mechanisms regulating ovarian-dependent tumour growth, on the one hand, and oestrogen and tamoxifen-induced tumour growth inhibition, on the other. The results support the view that the presence of receptors may be of importance but is not a sufficiently clear marker to allow prediction of the endocrine sensitivity of individual breast tumours.

M3 - Journal article

C2 - 3967950

VL - 35

SP - 59

EP - 64

JO - International Journal of Cancer

JF - International Journal of Cancer

SN - 0020-7136

IS - 1

ER -