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Mammary adenocarcinomas induced by medroxyprogesterone acetate: Hormone dependence and egf receptors of BALB/c In vivo sublines
Author(s) -
Lanari Claudia,
Kordon Edith,
Molinolo Alfredo,
Pasqualini Christiane Dosne,
Charreau Eduardo H.
Publication year - 1989
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910430518
Subject(s) - medroxyprogesterone acetate , endocrinology , medicine , in vivo , receptor , hormone , medroxyprogesterone , biology , transplantation , mammary gland , epidermal growth factor , mammary tumor , microgram , in vitro , cancer , biochemistry , breast cancer , microbiology and biotechnology
Mammary adenocarcinomas were induced by medroxyprogesterone acetate (MPA) in female BALB/c mice. From 5 primary tumors, 9 different sublines were established by s.c. transplantation into syngeneic female mice; these developed after a long latent period (4‐12 months). Each subline was transplanted both into 4 mice treated with 40mg of MPA depot (s.c. contralaterally to the tumor inoculum) and into 4 non‐treated mice. Of the 9 sublines, 6 proved to be hormonedependent (MPA‐D) and 3 hormone‐independent or autonomous (MPA‐I). However, even the autonomous lines, when treated with MPA, showed a slight increase in growth. All MPA‐D lines had a high content of ER (20‐254 fmoles/mg of protein), PR (63‐710), PRL‐R (44‐74) and low or nondetectable EGF‐R. Of the 3 MPA‐I sublines that were studied, 2 showed a high content of ER (16‐125), PR (27‐708), PRL‐R (19‐70) and EGF‐R (29‐65) while the other one had a low content of ER (0‐36), PR (0‐13), no EGF‐R and moderate PRL‐R (15‐52). Spontaneous mammary tumors of BALB/c and C3H origin, which also showed an MPA‐l pattern of tumor growth, had high levels of EGF‐R. We postulate that MPA has a direct effect on mammary tumor cells in MPA‐D lines and that the expression of EGF‐R is correlated with an autonomous pattern of growth.