Title: Effect of ovariectomy, hypophysectomy and/or GnRH administration oon the cell proliferation of the MXT mouse hormone-dependent mammary tumor
Authors: de Launoit, Y. ×
Kiss, R.
Danguy, A.
Paridaens, Robert #
Issue Date: 1988
Publisher: Pergamon
Series Title: European journal of cancer vol:23 pages:1433-1450
Abstract: The MXT tumor is an experimental mammary neoplasm which is maintained by serial transplantation using B6D2F1 mice, and which contains significant amounts of estrogen and progesterone receptors. The aim of the present study is to examine the effects of ovariectomy (OVX) or ovariectomy plus hypophysectomy (OVX-HX) on both the macroscopic growth and the cell proliferation of this tumor. This cell proliferation was evaluated by means of in vivo tritiated thymidine autoradiography. In addition, we investigated the effects of a GnRH analog (Gonadorelin: HRF, 5-oxo-Pro-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-hydrochloride) on MTX tumor cell proliferation on 7 day-OVX and 5 day-HX (OVX-HX) mice. The uterine luminal epithelium was chosen to monitor the methodology. Our data clearly demonstrate that there is a delay in the growth of MXT tumors grafted into hypophysectomized animals and, to a lesser degree, ovariectomized animals. With respect to proliferation, castration induced a dramatic decrease of the thymidine labelling index (TLI) in the tissue used to monitor the methodology (the uterine luminal epithemium); in contrast, no cell proliferation was induced by hypophysectomy or HRF administration. In 4-week-old MXT tumors, ovariectomy also markedly decreased the TLI within a few days of its taking place. However hypophysectomy, performed on castrated animals, induced a significant and transient increase of cell proliferation in this neoplasm, an increase which lasted from the 2nd to the 5th day following the operation. The high basal level of MXT cell proliferation recorded in OVX-HX animals decreased dramatically after the administration of HRF between 12 and 48 h prior to the sacrifice of the animals. It is concluded that the HRF exerts a direct effect on the MXT tumor cells, and this HRF might be essential for their growth.
ISSN: 0959-8049
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Laboratory of Experimental Oncology
× corresponding author
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science