# The Human Myometrial Transcriptome and the DNA Methylome of Testosterone-treated Patients Resemble the Myometria from Fibroid Patients

## TL;DR

Testosterone treatment in patients leads to myometrial changes similar to those seen in fibroid patients, suggesting a possible link between elevated testosterone and fibroid development.

## Contribution

This study is the first to show that testosterone induces myometrial transcriptomic and methylation changes resembling those in fibroid patients.

## Key findings

- Testosterone-treated myometrial tissues clustered with fibroid tissues in transcriptomic and methylation profiles.
- Fibroid-associated genes like TGFβ3, CCND1, SERPINE1, and FGFR1 were upregulated in testosterone-treated and fibroid samples.
- DNA methylation in testosterone-treated tissues was closer to fibroid tissues, but no correlation with gene expression was found.

## Abstract

Uterine fibroids, or leiomyomas, are noncancerous tumors of the myometrium and the most common tumors in women, with a cumulative incidence of approximately 80% by age 50. Currently, hysterectomy is the only definitive cure, and effective non-hormonal therapeutics are lacking. Understanding the etiology of fibroids may lead to alternative, less invasive treatments. Several obstetric disorders, including polycystic ovary syndrome (PCOS), have been linked to uterine fibroids, and women with PCOS often exhibit hormonal imbalances, particularly elevated serum testosterone levels. However, the impact of testosterone on the myometrium remains poorly understood. We hypothesize that elevated testosterone may increase the risk of developing uterine fibroids. Using RNA sequencing and MethylationEPIC array analyses, we compared myometrial tissue from women without fibroids (MyoN, n = 33), with fibroids (MyoF, n = 66), and after testosterone therapy as part of clinical care for gender dysphoria (MyoT, n = 7). The transcriptomic and methylation profiles of MyoT clustered with MyoF and were distinct from MyoN. We identified 1,321 differentially expressed protein-coding genes between MyoT and MyoN, while only 494 were found between MyoT and MyoF. Disease ontology analysis of MyoT vs. MyoN revealed enrichment of the fibroid tumor gene set. Fibroid associated genes including TGFβ3, CCND1, SERPINE1, and FGFR1 were upregulated in MyoT and MyoF samples compared to MyoN samples. The DNA methylation profiles of MyoT were closer to those of MyoF, but no correlation was observed between methylation status and gene expression. Our preliminary data suggest that exogenous testosterone induces transcriptional and methylation changes in the myometrium consistent with those observed in MyoF tissues. These findings suggest that elevated testosterone may be associated with an increased risk of developing uterine fibroids.

The online version contains supplementary material available at 10.1007/s43032-025-01893-9.