Enhancing Progestin Therapy with a Glucagon-Like Peptide 1 Agonist for the Conservative Management of Endometrial...

Obesity is a major risk factor for endometrial cancer. In addition to hormone therapy with progestins, glucagon like peptide-1 receptor (GLP-1R) agonists such as semaglutide may be helpful to achieve weight loss during conservative treatment of endometrial hyperplasia or cancer.

We theorized that the combination of semaglutide and the progestin levonorgestrel would be useful as a novel treatment or prevention regimen and tested this hypothesis using endometrial cancer cell lines and patient-derived organoids (PDOs).

Hec50, KLE, and Ishikawa endometrial cancer cells express GLP-1R, as determined by both qPCR and Western blotting, and GLP-1R agonist treatment induces GLP-1R mRNA transcription through positive feedback mechanisms in cell models. PDOs from six individuals with grade 1 endometrial carcinomas were treated with progesterone, levonorgestrel, semaglutide, or levonorgestrel + semaglutide. Multiple models demonstrated a significant reduction in viability in response to combinatorial treatment, and the effect was noted in models from both PR high- and PR low-expressing tumors. Most interesting was the induction not only of the membrane GLP-1R with treatment, but also the significant upregulation of nuclear and membrane progesterone receptors-PR and PGRMC1/2, respectively-indicating a potential positive feedback loop between semaglutide and progestins such as levonorgestrel.

In summary, we identify synergistic molecular cross-talk between the GLP-1R and steroid hormone receptor pathways, with the potential to enhance the anticancer activity of levonorgestrel when combined with semaglutide.