TY - JOUR
T1 - Combined effects of estradiol, leuprorelin, tamoxifen and medroxyprogesterone acetate on cell growth and steroid hormone receptors in breast cancer cells
AU - Sica, Gigliola
AU - Iacopino, Fortunata
AU - Cuna, Gioacchino Robustelli della
AU - Marchetti, Paolo
AU - Marini, Luca
PY - 1994/10
Y1 - 1994/10
N2 - Both tamoxifen and medroxyprogesterone acetate have a direct antitumor effect and are widely used in breast cancer therapy. Luteinizing-hormone-releasing hormone analogs inhibit the growth of breast cancer cells and could represent an alternative treatment for patients affected by breast cancer. Our study was carried out to investigate the effect of leuprorelin (TAP-144) alone or combined with tamoxifen or medroxyprogesterone acetate in human breast cancer cells. Ineffective when used in the absence of estrogens, TAP-144 inhibited the estrogen-stimulated growth of MCF-7, CG-5 and ZR-75-1 cells cultured in medium supplemented with charcoaltreated serum. The growth of estrogen-unresponsive MDA-MB-231 cells was not affected by TAP-144. The combination of TAP-144 with tamoxifen in CG-5 cells did not determine any enhancement of inhibition of cell growth, whereas in both CG-5 and MCF-7 cells, when 1 μM TAP-144 was associated with 0.1 μM medroxyprogesterone acetate, cell growth inhibition was increased, resulting in a subadditive effect. Progesterone receptor levels of CG-5 cells were significantly increased by TAP-144 in the presence of 17β-estradiol with respect to those present in control and 17β-estradiol-treated cells.
AB - Both tamoxifen and medroxyprogesterone acetate have a direct antitumor effect and are widely used in breast cancer therapy. Luteinizing-hormone-releasing hormone analogs inhibit the growth of breast cancer cells and could represent an alternative treatment for patients affected by breast cancer. Our study was carried out to investigate the effect of leuprorelin (TAP-144) alone or combined with tamoxifen or medroxyprogesterone acetate in human breast cancer cells. Ineffective when used in the absence of estrogens, TAP-144 inhibited the estrogen-stimulated growth of MCF-7, CG-5 and ZR-75-1 cells cultured in medium supplemented with charcoaltreated serum. The growth of estrogen-unresponsive MDA-MB-231 cells was not affected by TAP-144. The combination of TAP-144 with tamoxifen in CG-5 cells did not determine any enhancement of inhibition of cell growth, whereas in both CG-5 and MCF-7 cells, when 1 μM TAP-144 was associated with 0.1 μM medroxyprogesterone acetate, cell growth inhibition was increased, resulting in a subadditive effect. Progesterone receptor levels of CG-5 cells were significantly increased by TAP-144 in the presence of 17β-estradiol with respect to those present in control and 17β-estradiol-treated cells.
KW - Breast neoplasms
KW - Estrogen and progesterone receptors
KW - Leuprorelin
KW - Medroxyprogesterone acetate
KW - Tamoxifen
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U2 - 10.1007/BF01212815
DO - 10.1007/BF01212815
M3 - Article
C2 - 7929532
AN - SCOPUS:0027978565
VL - 120
SP - 605
EP - 609
JO - Journal of Cancer Research and Clinical Oncology
JF - Journal of Cancer Research and Clinical Oncology
SN - 0171-5216
IS - 10
ER -