Hormonal influences on the differentiation and growth of embryonic mouse mammary glands in organ culture

1959 ◽  
Vol 1 (4) ◽  
pp. 413-435 ◽  
Author(s):  
Etienne Y. Lasfargues ◽  
Margaret R. Murray
Keyword(s):  
Organ Culture ◽  
Mammary Glands ◽  
Embryonic Mouse

Effect of Vitamin C Plus Reducing Agents on Production of Cartilage by Embryonic Mouse Radii Grown in Organ Culture

1970 ◽  
Vol 5 (4) ◽  
pp. 282
Author(s):  
Henry H. Jones ◽  
Margaret McHardy-Young ◽  
James Breeden ◽  
Geraldine Gribble
Keyword(s):  
Vitamin C ◽  
Organ Culture ◽  
Reducing Agents ◽  
Embryonic Mouse

scholarly journals Functional Significance of Selective Expression of ERα and ERβ in Mammary Gland Organ Culture

2021 ◽  
Vol 22 (23) ◽  
pp. 13151
Author(s):  
Rajendra G. Mehta
Keyword(s):  
Organ Culture ◽  
Functional Significance ◽  
Precancerous Lesions ◽  
Mammary Glands ◽  
Short Exposure ◽  
Preneoplastic Lesions ◽  
Organ Cultures ◽  
Regulated Gene Expression ◽  
Microarray Analyses ◽  
Map Kinase Pathways

Thoracic pair of mammary glands from steroid hormone-pretreated mice respond to hormones structurally and functionally in organ culture. A short exposure of glands for 24 h to 7,12 Dimethylbenz(a)anthracene (DMBA) during a 24-day culture period induced alveolar or ductal lesions. Methods: To differentiate the functional significance of ERα and ERβ, we employed estrogen receptor (ER) knockout mice. We compared the effects of DMBA on the development of preneoplastic lesions in the glands in the absence of ERα (αERKO) and ERβ (βERKO) using an MMOC protocol. Glands were also subjected to microarray analyses. We showed that estradiol can be replaced by EGF for pretreatment of mice. The carcinogen-induced lesions developed under both steroids and EGF pretreatment protocols. The glands from αERKO did not develop any lesions, whereas in βERKO mice in which ERα is intact, mammary alveolar lesions developed. Comparison of microarrays of control, αERKO and βERKO mice showed that ERα was largely responsible for proliferation and the MAP kinase pathways, whereas ERβ regulated steroid metabolism-related genes. The results indicate that ERα is essential for the development of precancerous lesions. Both subtypes, ERα and Erβ, differentially regulated gene expression in mammary glands in organ cultures.

CORRELATION BETWEEN THE EFFECTS OF HORMONES ON THE SYNTHESIS OF DNA IN EXPLANTS FROM INDUCED RAT MAMMARY TUMOURS AND THE GROWTH OF THE TUMOURS

1974 ◽  
Vol 62 (2) ◽  
pp. 225-240 ◽  
Author(s):  
D. LEWIS ◽  
R. C. HALLOWES
Keyword(s):  
Organ Culture ◽  
Dna Synthesis ◽  
Culture Medium ◽  
Mammary Glands ◽  
Sprague Dawley ◽  
Culture Techniques ◽  
Mammary Tumours ◽  
Sprague Dawley Rats

SUMMARY Explants from 32 mammary tumours induced in Sprague—Dawley rats by 9,10-dimethyl-1,2-benzanthracene (DMBA) were maintained in organ culture for up to 48 h. Insulin, corticosterone, prolactin, growth hormone and oestradiol were added to the culture medium in various combinations and their effects on the DNA synthesis of the explants was studied. DNA synthesis was stimulated by insulin in explants from 30 out of the 32 tumours examined and this group of 30 responsive tumours could be further subdivided. Explants from 16 tumours showed a greater rate of DNA synthesis in medium containing insulin plus corticosterone plus prolactin than in medium containing insulin alone and this higher rate was decreased by oestradiol; this group is referred to as 'prolactin-responsive'. Explants from the remaining 14 tumours did not show a greater rate of DNA synthesis in medium that contained insulin plus corticosterone plus prolactin than in medium containing insulin alone and neither rate was decreased by oestradiol; this group is referred to as 'insulin-responsive'. Explants from two tumours were not stimulated by insulin and these tumours are referred to as 'non-responsive'. After oophorectomy or administration of ergocryptine to tumour-bearing rats, the prolactin-responsive tumours regressed whereas the non-responsive tumours continued to grow. Explants taken from prolactin-responsive tumours 2 weeks after either oophorectomy or administration of ergocryptine were still prolactin-responsive but those taken from insulin-responsive tumours 2 weeks after the same treatment were now also prolactin-responsive. The non-responsive tumours remained non-responsive. The effects of hormones on the DNA synthesis in vitro of explants from growing DMBA-induced tumours were thus different from those on explants of mammary glands from virgin or pregnant Sprague—Dawley rats. It was concluded that it was possible to predict by organ culture techniques the response in vivo of growing mammary tumours to oophorectomy and ergocryptine administration.

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