Poster Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

Extracellular matrix (ECM) and Wnt signalling nexus in human uterine leiomyomas (#293)

Yi-An Ko 1 , M. Fairuz B. Jamaluddin 1 , Pradeep S. Tanwar 1
  1. University of Newcastle, Newcastle, NSW, Australia

Uterine leiomyomas (fibroids) are the most prevalent benign tumours that occur in 60% of premenopausal women.  The majority of these women are presented with symptoms ranging from pain and discomfort to infertility.  The main treatment for this disease is still limited to hysterectomy and myomectomy which creates enormous healthcare burden worldwide. Understanding of the mechanisms involved in the pathogenesis of fibroids is likely to reveal new and unique targets for the development of non-surgical treatments for this disease.


Recent advancement in genetic sequencing has revealed the most prevalent mutation in Mediator Subunit 12 gene (MED12) which contributes to 70% of the fibroids. Hyperactivation of WNT/b-catenin signalling was also identified in fibroid development. MED12 is known to regulate Wnt signalling and can bind directly to b-catenin to assist the downstream transcription.  Med12 knockout studies have revealed that this gene is essential for early mouse embryonic development. Despite the known connection between MED12 and WNT/b-catenin signalling, little is known for whether MED12 deletion/mutations contribute to fibroid pathogenesis through WNT/b-catenin signalling.


In the present study, we examined the MED12 mutational status of fibroid tumours (N=19) against the paired adjacent normal myometrium (n=12). The expression status of WNT/b-catenin signalling was examined using real-time PCR (qPCR) and mass spectrometry, and confirmed with western blot and Immunohistochemistry (IHC). The result showed no direct association between MED12 mutation status and b-catenin in both RNA and protein level, which suggests the mutation in MED12 gene is not the cause of b-catenin upregulation.  By culturing primary leiomyoma cell on the different stiffness of hydrogels, we observed increased level of b-catenin expression with increased ECM stiffness suggesting that excessive ECM, but not MED12 mutations, is responsible for b-catenin activation in uterine fibroids.  In conclusion, our study revealed a novel mechanism of b-catenin activation in human uterine fibroids.