Low Dose, Low Cost Estradiol Pellets Can Support MCF-7 Tumour Growth in Nude Mice without Bladder Symptoms

Abstract

MCF-7 cells are a slow growing estrogen receptor (ER) positive human breast cancer cell line that is commonly used to model estrogen responsive breast cancer cell growth in-vitro and tumour growth in-vivo. These tumours require estrogen supplementation, and in-vivo doses of between 0.72mg and 2mg estradiol pellets are commonly implanted in the dorsal flank of ovariectomised, immunocompromised mice. We wanted to grow MCF-7 tumours in immunocompromised mice without the need to be ovariectomised. When we treated immunocompromised mice with 0.72mg pellets to induce MCF7 tumour growth, the mice developed urosepsis. We have now shown that lower doses of estradiol pellets, 0.3mg and 0.5mg, induce elevated serum estrogen levels and maintain tumour growth, without causing urosepsis. Supplementation for only one week did not support sustained MCF7 tumour growth. In conclusion, 0.3mg and 0.5mg silastic pellets can be used to stimulate ER+ breast cancer growth in ovary-intact, immune compromised mice.

Mimicking Sampson’s Retrograde Menstrual Theory in Rats: A New Rat Model for Ongoing Endometriosis-Associated Pain

“…This is in contrast to the mouse model, where recipients continuously received estrogen via a silastic implant, enabling proliferation of the lesions [9]. These implants, however, are also associated with urinary retention and bladder cystitis [32], two phenotypes that might interfere with the endometriosis-associated pain measurements. By relying on the natural estrus cycle, the use of estrogen pellets becomes redundant, thus evading these interfering bladder pain phenotypes.…”

Calmodulin-like protein 3 is an estrogen receptor alpha coregulator for gene expression and drug response in a SNP, estrogen, and SERM-dependent fashion

“…6 ). Of importance, both E2 and drug concentrations used in these studies were within physiological and therapeutic ranges [ 33 – 35 ].…”

Enrichment and detection of bone disseminated tumor cells in models of low tumor burden

“…We 17 and others 18 , 19 have reported that the human MCF7 (ER+) cell line is non-proliferative in the lung and bone and induces little osteolytic bone destruction, and have proposed this cell line as a clinically relevant model of tumor dormancy. Previous literature reports that MCF7 cells require exogenous 17β-estradiol (E2) to form orthotopic tumors and bone metastases 20 , 21 ; however, E2 results in a dramatic increase in bone volume 22 and perturbation of normal bone microarchitecture in tumor-inoculated as well as naïve mice. Further, estrogen supplementation causes adverse urinary tract effects resulting in mice being sacrificed before the experimental end-point 20 , 23 .…”