Scientists at KU Leuven have managed to grow three–dimensional models of the endometrium in a dish. These so–called endometrial organoids can help shed light on the underlying mechanisms of the menstrual cycle. They also make it possible to study endometrial cancer and other diseases of the uterus in a lab dish.

Little is understood about the underlying mechanisms of endometrium cycling and disease, mainly because we lack good culture models for endometrial tissue.

KU Leuven researchers have now shown that cells from uterus biopsies can be made to grow into three–dimensional structures that imitate the menstrual cycle in a dish. “These tiny structures reproduce the endometrium’s normal responses to oestrogen and progesterone,” explains Matteo Boretto from the KU Leuven Department of Development and Regeneration and first author on the study. “Oestrogen makes the endometrial tissue thicken. Progesterone then makes it mature and fold. Finally, when you remove both hormones the organoids imitate the cell shedding at the end of the menstrual cycle.”

The endometrial organoids produced in the lab represent a part of the structure that makes up the uterus. The researchers hope that it will soon be possible to grow these organoids together with other endometrial cells for a more complete model of the uterus.

This may lead to better treatments for diseases of the endometrium and the fertility problems they cause. “In the meantime, our new organoid model already offers several exciting possibilities,” says Professor Hugo Vankelecom from the KU Leuven Department of Development and Regeneration and lead author of the study. “It will boost our understanding of how the uterus responds to hormones during the menstrual cycle. The method will also make it possible to grow organoids from the tissue of patients with endometrial diseases such as atrophy (thinning) and cancer. Endometrial biopsies are usually very small in size, so having a reliable technique to grow and expand the tissue in a dish is a big step forward: it allows for an in–depth study of the disease that simply wasn’t possible before. Last but not least, the endometrial organoids will allow us to test the efficiency and toxicity of new drugs for endometrial diseases. This may lead to better treatments for these diseases and the fertility problems they cause. All this makes our new model potentially interesting for companies as well.”

The study was published in the journal Development.