How does tamoxifen induce Cre?
It utilizes a mutated estrogen receptor (ER) fused to Cre as a transgene (Cre-ER), which only becomes activated and then translocates into the nucleus upon binding of the active tamoxifen (TAM) metabolite 4-hydroxytamoxifen (4-OHT), which mutates the ER.
What is CreERT2?
CreERT2 encodes a Cre recombinase (Cre) fused to a mutant estrogen ligand-binding domain (ERT2) that requires the presence of tamoxifen for activity. We have previously shown that heterozygous Na(V)1.8-Cre mice will delete loxP flanked genes specifically in nociceptive sensory neurons from embryonic day 14.
How long does it take for Cre recombinase to work?
By lipofection, it would take about one day for the Cre to be expressed and then it should be immediately active.
What is the mechanism of action of tamoxifen?
Tamoxifen (TAM) is known to have a dual mechanism of action: (1) to compete with 17β-estradiol (E2) at the receptor site and to block the promotional role of E2 in breast cancer; and (2) to bind DNA after metabolic activation and to initiate carcinogenesis.
What is tamoxifen induction?
Introduction. Tamoxifen is widely used for the induction of genomic recombination in mice (double-)transgenic for floxed genes and Tamoxifen specific estrogen receptors (ER) coupled to Cre-recombinase (supplemental Table 1) (Hayashi and McMahon 2002).
Why is tamoxifen used in mice?
Tamoxifen is widely used for the induction of genomic recombination in mice (double-)transgenic for floxed genes and Tamoxifen specific estrogen receptors (ER) coupled to Cre-recombinase (supplemental Table 1) (Hayashi and McMahon 2002).
Is Tamoxifen toxic to mice?
These results identify the toxic effects of higher doses of TAM administered, particularly when given IP. Treating mice with high dose of TAM increases YFP induction among CD45+ cells but also results in liver injury. (A) Frequency of YFP-expressing CD45+ cells after PO administration of TAM at 3 or 6 mg.
Does tamoxifen stop periods?
Fertility, pregnancy and tamoxifen For some women, continued use of tamoxifen means periods become less regular, lighter or stop altogether. Generally, your periods will start again once you stop taking tamoxifen, as long as you have not gone through the menopause naturally while taking the drug.
What does tamoxifen do to your brain?
A team from the University of Rochester Medical Center has shown scientifically what many women report anecdotally: that the breast cancer drug tamoxifen is toxic to cells of the brain and central nervous system, producing mental fogginess similar to “chemo brain.”
What does tamoxifen do to the body?
Tamoxifen is a type of hormonal therapy known as a selective estrogen receptor modulator (SERM). The drug attaches to hormone receptors (specific proteins) in breast cancer cells. Once the medication is inside the cells, it stops the cancer from accessing the hormones they need to multiply and grow.
How long does tamoxifen stay in a mouse?
Mouse age also plays an important role, because aged mice showed a high mortality rate after 2 × 200 mg/kg of tamoxifen administration, and they were unable to degrade tamoxifen or its metabolites within 6 days.
What is inducible Cre?
11. Inducible Cre can be leaky. Cre is sequestered in the cytoplasm when it is fused to the ligand binding domain of the estrogen receptor, and enters the nucleus when exposed to tamoxifen.
Where is Cre recombinase expressed?
The Cre recombinase gene expression may be under the control of the Tet-On system, itself under the control of a cell-specific promoter.
What does creert2 stand for?
Mutant Estrogen Receptor (ERT2) ligand-binding domain fusions with Cre recombinase are a key tool for spatio-temporally controlled genetic recombination with the Cre/lox system. CreERT2 is efficiently activated in a concentration-dependent manner by the Tamoxifen metabolite trans-4-OH-Tamoxifen (tra …
How is creert2 activated by tamoxifen?
CreERT2 is efficiently activated in a concentration-dependent manner by the Tamoxifen metabolite trans-4-OH-Tamoxifen (tra … In Vivo Performance and Properties of Tamoxifen Metabolites for CreERT2 Control
Is CRE ERT2 sensitive to 4-OH-Tam?
While this protein complex is impervious to natural ligands, it is highly sensitive to synthetic estrogen antagonists, such as 4-OH-TAM 12, 13 which liberate the Cre ERT2 for recombination of floxed alleles in the cell nucleus.
How effective is 4-OH-Tam in glast-creert2 Knockin mice?
Others have also demonstrated a more efficient Cre activity in GLAST-CreERT2 knockin mice after i.p. injection of tamoxifen when compared to oral gavage 18. The minimal effective concentration of 4-OH-TAM has been determined at 38 ± 22 ng/g 24.