R. van Amerongen
- The influence of tamoxifen on normal mouse mammary gland homeostasis
- Breast Cancer Research
- Volume | Issue number
- 16 | 4
- Number of pages
- Document type
- Faculty of Science (FNWI)
- Swammerdam Institute for Life Sciences (SILS)
Introduction: Lineage tracing using inducible genetic labelling has emerged to be a powerful method for interrogating the developmental fate of cells in intact tissues. A common induction mechanism is the use of tamoxifen-dependent Cre recombinase (CreER and CreERT2), but the effects of tamoxifen at doses normally used in lineage tracing studies on normal adult mammary gland homeostasis are not known.
Methods: We used flow cytometry and immunostaining of intact glands to determine if varying doses of tamoxifen skews the distribution and the apoptosis and proliferation status of different types of mammary epithelial cells in vivo. We also examined how tamoxifen influences the number of progenitor and mammary repopulating units (MRUs).
Results: Our results indicate that inverted question mark5 mg/25 g body weight of tamoxifen induces a transient increase in cell proliferation and in the number of basal cells in the adult mammary epithelium up to seven days after tamoxifen administration. However, in the medium term (three weeks), all doses of tamoxifen inverted question mark1 mg/25 g body weight results in a decrease in the number of basal and EpCAM+CD49b inverted question mark luminal cells and a decrease in progenitor cell function. Tamoxifen at doses inverted question mark5 mg/25 g body weight induced a transient increase in caspase-3 mediated apoptotic cell death within the mammary epithelium. However, mammary epithelial cell numbers in all subpopulations were restored to their original levels by eight weeks. No long lasting effects of tamoxifen on mammary repopulating unit numbers or on pubertal ductal development were observed.
Conclusion: Tamoxifen can skew the distribution of mammary cell types in a dose dependent manner, and thus caution must be taken when interpreting lineage tracing studies using high doses of tamoxifen, particular when short duration analyses of a quantitative nature are being performed.
- go to publisher's site
- With additional files
- Supplementary materials
If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library, or send a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible.