A GHRH Antagonist Peptide Shrinks Endometriosis Tissue in Mice and Cell Cultures

The study combined in vitro and in vivo approaches. Researchers first confirmed GHRH receptor SV1 expression in human endometrial tissue using Western blots and qRT-PCR. They then tested MIA-602 in a mouse xenotransplant model where human endometrial tissue from endometriosis patients was implanted into mice. Cell culture experiments used endometrial stromal cells and two established endometriosis cell lines (12-Z and 49-Z) to measure proliferation and signaling pathway changes.

Endometriosis affects an estimated 10% of reproductive-age women and current treatments — hormonal suppression and surgery — have significant limitations and side effects. Finding that endometriosis tissue expresses GHRH receptors opens a completely new treatment target. A peptide antagonist that can shrink endometriosis by blocking growth signaling could offer an alternative to hormonal therapy without the same endocrine side effects.

This study is part of a broader research program led by Nobel laureate Andrew Schally exploring GHRH antagonists as anti-proliferative agents beyond their original growth hormone context. The finding that endometriosis expresses the SV1 receptor adds this condition to a growing list of diseases — including several cancers — where GHRH antagonist peptides show therapeutic potential. It represents a shift from hormonal suppression toward targeted receptor-based therapy for endometriosis.

This is a preclinical study using a mouse xenotransplant model, which may not fully replicate human endometriosis. The mouse model uses immunodeficient (nude) mice, removing the immune component of the disease. Sample sizes for human tissue analysis are not specified. The drug has not been tested in human clinical trials for endometriosis. Long-term effects and side effects of GHRH antagonism are unknown. The endometriosis cell lines used may not perfectly represent all forms of the disease.