Estrogen-sensitive tissues and cancer

Our Research

In the field of endocrinology and cancer, our group brings fundamental and translational data to contribute to the development of menopause hormone treatment (MHT) with optimized benefit/risk ratio. In that view, our research projects are focused on the characterization of the impact of several MHT on several target tissues including breast cancer, mammary gland, endometrium or brain, revealing their molecular mechanisms of action. We are also interested in several sex-related cellular and molecular interactions occurring in tumor microenvironment, contributing to angiogenesis and lymphangiogenesis. 

Impact of Estetrol on mammary gland development, breast cancer progression and menopause 

One of our goals is to anticipate the effect of menopause hormone treatment (MHT) on estrogen-sensitive tissues and to generate robust translational data (Gallez 2021, Cancers (Basel). 2021 May 20;13(10):2486. doi: 10.3390/cancers13102486). Thus, to model human treatments and to define MHT effects on physiology or pathophysiology, it is essential to adapt the pattern of MHT administration to in vivo animal models in a way that closely mimics MHT exposure in women. In that view, we recently compared estetrol (E4, a natural estrogen) pharmacokinetic between women and mice (Gallez 2023, Int J Mol Sci. 2023 Jun 3;24(11):9718. doi: 10.3390/ijms24119718). Our results highlight the importance to carefully consider the most appropriate dose and route of estrogen administration to be used in predictive preclinical animal models to mimic specific human treatments. 

For this pharmacokinetic study, we developed the quantitation of E4 on whole blood microsampling (10µl) in collaboration with Prof. M. Fillet and G. Piel (CIRM, ULiège, Belgium) (Nys 2017, J Pharm Biomed Anal. 2017 Jun 5;140:258-265. doi: 10.1016/j.jpba.2017.02.060). We also characterized that the accurate control of E2 release with long-term releasing devices increases the reliability and the reproducibility of preclinical animal studies, especially in breast cancer models (Gérard 2017, J Mammary Gland Biol Neoplasia. 2017 Mar;22(1):1-11. doi: 10.1007/s10911-016-9368-1). 

In addition to previous studies showing that E4 acts as a weak estrogen by stimulating the growth of hormone-dependent breast cancer only at concentrations exceeding menopausal therapeutic needs (Gérard 2015, Oncotarget. 2015 Jul 10;6(19):17621-36. doi: 10.18632/oncotarget.4184), we recently evidenced that E4 was neutral on breast cancer growth even when it was combined to progestogens such as progesterone or drospirenone for menopause indication (Gallez 2021, Cancers (Basel). 2021 May 20;13(10):2486. doi: 10.3390/cancers13102486). Through in vivo observations using MMTV-PyMT transgenic mice, MCF7 cell xenograft and breast cancer PDX and through transcriptomic analyses, our translational preclinical research evidenced that combining a progestogen to E4 is neutral on breast cancer growth and dissemination, with very limited transcriptional impact. 

We showed that E4 differs from estradiol (E2) as it exhibits a distinctive and tissue specific activation profile of ERα (Abot 2014, EMBO Mol Med. 2014 Oct;6(10):1328-46. doi: 10.15252/emmm.201404112). E4 acts as an agonist of the nuclear form of ERα (genomic pathway), but it can antagonize the membrane-anchored form of ERα (Membrane Initiated Steroid Signaling, MISS pathway) in some tissues such as the endothelium. To further study in-depth these two molecular pathways, we demonstrated that the inclusion of estrogen into nanovehicle such as liposome produced pharmacological tools specifically stimulating the ERα genomic pathway (Gallez 2020, Int J Pharm. 2020 Jan 5;573:118861. doi: 10.1016/j.ijpharm.2019.118861). 

We studied the impact of E4 on mammary gland development and observed that E4 is a weak estrogen because it was 100 times less potent than E2 to stimulate murine mammary development (Gérard 2015, J Endocrinol. 2015 Jan;224(1):85-95. doi: 10.1530/JOE-14-0549). This is currently the only study available in the scientific literature focusing on the impact of E4 on the mammary gland. To quantify the growth and morphological changes observed in mammary gland upon various treatments, we have developed an automated method of image analysis (Blacher 2016, Endocrinology. 2016 Apr;157(4):1709-16. doi: 10.1210/en.2015-1601). 

MHT and endometrium 

Since the endometrium is highly sensitive to estrogens and, as a consequence, is an important side target of menopause hormone treatments (MHT), we are developing experimental models to study the impact of MHT on human endometrium and potentially anticipate their effects. 

Unraveling the Dynamics of Estrogen and Progesterone Signaling in the Endometrium: An Overview. 
Dias Da Silva I, Wuidar V, Zielonka M, Pequeux C. Cells. 2024 Jul 23;13(15):1236. doi: 10.3390/cells13151236 

Tumour microenvironment 

Estrogens play pleiotropic roles in pathophysiology, especially in tumor microenvironment (Wuidar, Adv Exp Med Biol. 2021;1329:499-533. doi: 10.1007/978-3-030-73119-9_23). Our works highlighted that estrogen and female microenvironment sustain more efficiently the development of estrogen receptor-negative tumors such as lung cancer or melanoma (Pequeux 2012, Cancer Res. 2012 Jun 15;72(12):3010-9. doi: 10.1158/0008-5472.CAN-11-3768). Especially, estrogens increase lymph/angiogenesis and vascular normalization through an ERa-dependent pathway. In accordance, treatment by ERa antagonist or tamoxifen decreases lung tumour growth and lymph/angiogenesis in females but not in males (Dubois, Endocr Relat Cancer. 2019 Feb;26(2):201-216. doi: 10.1530/ERC-18-0328). We also evidenced in collaboration with Dr. F. Lenfant (INSERM Toulouse, France) that both nuclear and membrane ERα actions are essential for the pro-tumor effects of E2, while tamoxifen completely suppresses E2-induced tumor growth in vivo by inhibiting angiogenesis and promoting vessel. These processes occur through a reprogramming of endothelial gene expression, impacting the regulation of certain transcription factors (Febrisy, Theranostics. 2024 Jan 1;14(1):249-264. doi: 10.7150/thno.87306. eCollection 2024). 

We reinforced our expertise in breast and lung cancer pathophysiology and metastasis dissemination. In collaboration with Prof. A. Noël and D. Cataldo (ULiège), we contributed to characterize the implication of stromal integrin α11 to breast cancer development (Primac, J Clin Invest. 2019 Jul 9;129(11):4609-4628. doi: 10.1172/JCI125890) and the impact of ozone on metastasis dissemination to the lung (Rocks, Thorax. 2019 Aug;74(8):768-779. doi: 10.1136/thoraxjnl-2018-211990). 

Estrogen and neuroprotection

We are focusing our work on Neonatal Hypoxic-ischemic encephalopathy (HIE), a recognized rare disease (ORPHA:137577). It remains a serious condition that causes significant mortality and morbidity in newborns. HIE results from the incapacity of the newborn brain to accommodate the hypoxic stress. Even though different therapeutic strategies have been developed recently, neonatal HIE still remains a challenge for perinatal medicine and an unmet medical need. We demonstrated for the first time that Estetrol is neuroprotective in experimental HIE. Based on experimental results provided by our team, the European Medicines Agency (EMA) granted Estetrol with the orphan drug designation (ODD). 

In addition, we are also interested in the impact of estrogen on auditory function, in collaboration with Prof. Delacroix and Malgrange (GIGA-Neurosciences, ULiège, Belgium). 

Main publications of the team in the field

Auditory function and dysfunction: estrogen makes a difference. 
Delhez A, Lefebvre P, Péqueux C, Malgrange B, Delacroix L. Cell Mol Life Sci. 2020 Feb;77(4):619-635. doi: 10.1007/s00018-019-03295-y. 

Use of liposome-encapsulated estetrol for treatment of neonatal hypoxic-ischemic encephalopathy. 
Tskitishvili E, Palazzo C, Foidart JM, Piel G, Pequeux C. Brain Res. 2023 Jun 15;1809:148369. doi: 10.1016/j.brainres.2023.148369. 

Development of injectable liposomes and drug-in-cyclodextrin-in-liposome formulations encapsulating estetrol to prevent cerebral ischemia of premature babies. 
Palazzo C, Laloy J, Delvigne AS, Nys G, Fillet M, Dogne JM, Pequeux C, Foidart JM, Evrard B, Piel G. Eur J Pharm Sci. 2019 Jan 15;127:52-59. doi: 10.1016/j.ejps.2018.10.006. 

Estrogen receptors and estetrol-dependent neuroprotective actions: a pilot study. 
Tskitishvili E, Pequeux C, Munaut C, Viellevoye R, Nisolle M, Noël A, Foidart JM. J Endocrinol. 2017 Jan;232(1):85-95. doi: 10.1530/JOE-16-0434 

Use of estetrol with other steroids for attenuation of neonatal hypoxic-ischemic brain injury: to combine or not to combine? 
Tskitishvili E, Pequeux C, Munaut C, Viellevoye R, Nisolle M, Noël A, Foidart JM. Oncotarget. 2016 Jun 7;7(23):33722-43. doi: 10.18632/oncotarget.9591 

Estetrol attenuates neonatal hypoxic-ischemic brain injury.
Tskitishvili E, Nisolle M, Munaut C, Pequeux C, Gerard C, Noel A, Foidart JM. Exp Neurol. 2014 Nov;261:298-307. doi: 10.1016/j.expneurol.2014.07.015.