The Contribution of Hypoxia-Inducible Factor (HIF) -1 Alpha to Normal Mammary Gland Development and Mammary Tumorigenesis

2003 ◽  
Author(s):  
Tiffany N. Seagroves
Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3577-3588 ◽  
Author(s):  
Mark D. Aupperlee ◽  
Kyle T. Smith ◽  
Anastasia Kariagina ◽  
Sandra Z. Haslam

Abstract Progesterone is a potent mitogen in the mammary gland. Based on studies using cells and animals engineered to express progesterone receptor (PR) isoforms A or B, PRA and PRB are believed to have different functions. Using an immunohistochemical approach with antibodies specific for PRA only or PRB only, we show that PRA and PRB expression in mammary epithelial cells is temporally and spatially separated during normal mammary gland development in the BALB/c mouse. In the virgin mammary gland when ductal development is active, the only PR protein isoform expressed was PRA. PRA levels were significantly lower during pregnancy, suggesting a minor role at this stage of development. PRB was abundantly expressed only during pregnancy, during alveologenesis. PRA and PRB colocalization occurred in only a small percentage of cells. During pregnancy there was extensive colocalization of PRB with 5-bromo-2′-deoxyuridine (BrdU) and cyclin D1; 95% of BrdU-positive cells and 83% of cyclin D1-positive cells expressed PRB. No colocalization of PRA with either BrdU or cyclin D1 was observed at pregnancy. In the virgin gland, PRA colocalization with BrdU or cyclin D1 was low; only 27% of BrdU-positive cells and 4% of cyclin D1-positive cells expressed PRA. The implication of these findings is that different actions of progesterone are mediated in PRB positive vs. PRA-positive cells in vivo. The spatial and temporal separation of PR isoform expression in mouse mammary gland provides a unique opportunity to determine the specific functions of PRA vs. PRB in vivo.


PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e101546 ◽  
Author(s):  
Michael K. G. Stewart ◽  
Isabelle Plante ◽  
John F. Bechberger ◽  
Christian C. Naus ◽  
Dale W. Laird

2020 ◽  
Vol 32 (8) ◽  
pp. 774
Author(s):  
Vahid Atashgaran ◽  
Pallave Dasari ◽  
Leigh J. Hodson ◽  
Andreas Evdokiou ◽  
Simon C. Barry ◽  
...  

Female mice heterozygous for a genetic mutation in transcription factor forkhead box p3 (Foxp3) spontaneously develop mammary cancers; however, the underlying mechanism is not well understood. We hypothesised that increased cancer susceptibility is associated with an underlying perturbation in mammary gland development. The role of Foxp3 in mammary ductal morphogenesis was investigated in heterozygous Foxp3Sf/+ and wildtype Foxp3+/+ mice during puberty and at specific stages of the oestrous cycle. No differences in mammary ductal branching morphogenesis, terminal end bud formation or ductal elongation were observed in pubertal Foxp3Sf/+ mice compared with Foxp3+/+ mice. During adulthood, all mice underwent normal regular oestrous cycles. No differences in epithelial branching morphology were detected in mammary glands from mice at the oestrus, metoestrus, dioestrus and pro-oestrus stages of the cycle. Furthermore, abundance of Foxp3 mRNA and protein in the mammary gland and lymph nodes was not altered in Foxp3Sf/+ mice compared with Foxp3+/+ mice. These studies suggest that Foxp3 heterozygosity does not overtly affect mammary gland development during puberty or the oestrous cycle. Further studies are required to dissect the underlying mechanisms of increased mammary cancer susceptibility in Foxp3Sf/+ heterozygous mice and the function of this transcription factor in normal mammary gland development.


2000 ◽  
pp. 257-269 ◽  
Author(s):  
R Kumar ◽  
R K Vadlamudi ◽  
L Adam

Homeostasis in normal tissue is regulated by a balance between proliferative activity and cell loss by apoptosis. Apoptosis is a physiological mechanism of cell loss that depends on both pre-existing proteins and de novo protein synthesis, and the process of apoptosis is integral to normal mammary gland development and in many diseases, including breast cancer. The mammary gland is one of the few organ systems in mammals that completes its morphologic development postnatally during two discrete physiologic states, puberty and pregnancy. The susceptibility of the mammary gland to tumorigenesis is influenced by its normal development, particularly during stages of puberty and pregnancy that are characterized by marked alterations in breast cell proliferation and differentiation. Numerous epidemiologic studies have suggested that specific details in the development of the mammary gland play a critical role in breast cancer risk. Mammary gland development is characterized by dynamic changes in the expression profiles of Bcl-2 family members. The expression of Bcl-2 family proteins in breast cancer is also influenced by estradiol and by progestin. Since the ratio of proapoptotic to antiapoptotic proteins determines apoptosis or cell survival, hormone levels may have important implications in the therapeutic prevention of breast cancer.


2004 ◽  
Vol 33 (1) ◽  
pp. 195-207 ◽  
Author(s):  
M Boutinaud ◽  
JH Shand ◽  
MA Park ◽  
K Phillips ◽  
J Beattie ◽  
...  

We have used quantitative RT-PCR to analyse the mRNA expression profile of the major components of the IGF axis in different stages of murine mammary gland development, including late pregnancy, lactation and involution. We have shown that all the genes studied, IGF-I, IGF-II, IGF receptor (IGFR) and IGF-binding protein (IGFBP)-1 to -6, were expressed in every stage, albeit at greatly differing levels and displaying unique expression profiles between developmental stages. IGF-I was always expressed at significantly higher levels than either IGF-II or IGFR. This suggests that IGF-I may be the more important IGF during mammary morphogenesis. Overall, IGFBP-3 demonstrated the highest level of expression of any of the IGFBP genes throughout all the developmental stages studied. However, within developmental stages, by far the highest level of expression of any of the IGFBPs was that of IGFBP-5 at day 2 of involution; this was almost an order of magnitude higher than any of the other IGFBP levels recorded. This corroborated our previous findings that the levels of IGFBP-5 protein are highly elevated in the involuting mammary gland, and demonstrated that this up-regulation of IGFBP-5 operates at the level of transcriptional control or message stability. Comparison of the expression profile for these different genes would strongly suggest that they are likely to have differential functions throughout mammary gland development, and also highlights potential interactions and co-regulation between different members of this axis. In addition, our results have identified some similarities and differences in the expression of IGFBPs between the mouse mammary epithelial cell line, HC11, and the normal mammary gland which are worthy of study, most notably the differential regulation of IGFBP-2 and the site of expression of IGFBP-4 and -6. Overall, this study has demonstrated the importance and complexity of the IGF axis during mammary gland development and provides a valuable resource for future research in this area.


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