Heterogeneity of estrogen receptor α and progesterone receptor distribution in lesions of deep infiltrating endometriosis of untreated women or during exposure to various hormonal treatments

<p>Deep infiltrating endometriosis (DIE) responds variably to hormonal therapy. Mutations in cancer driver genes have been identified in a fraction of the ectopic endometrial epithelial cells, suggesting a functional heterogeneity of these lesions. To evaluate the phenotype heterogeneity of cells in DIE, we measured the expression of estrogen receptor α (ERα) and of progesterone receptor (PR) in DIE of untreated women or under various treatments. We analyzed the luminal epithelial height (LEH), immunoreactive epithelial staining (IRS) and stromal staining intensity (SSI) of ERα and PR. We observed a high variability in the same gland, among distinct glands in the same sample and among distinct patients receiving the same treatment. LEH variability was primarily due to epithelial cells heterogeneity in a gland, secondarily to the glands randomly evaluated on the same section, and tertiary to the patient category. Variability in IRS and SSI scores was primarily the consequence of their heterogeneity in the same woman and to a lesser extent to variability among patients. LEH and SSI were not modified according to treatment. IRS for PR was lower in treated patients. This heterogeneity of ERα and PR distribution could explain why endocrine treatments are unable to cure this condition.</p

Flow chart of the experimental design (A) and representative histology of a sheep cortex section (B).

<p>Ovaries were harvested from two ewes and fully cut into cortical fragments. Subsequently, each fragment was serially and completely sectioned, and approximately 40 H&E sections, each 30 µm apart from one another, were further used for the follicular quantification (A). The uneven repartition of follicles within the sheep ovarian cortex is obvious (B). The left part of the H&E section is completely devoid of primordial follicles, whereas the right part contains mostly primordial follicles. Primordial follicles (plain arrows) and secondary follicles (arrowhead).</p

Variance components of the random-effects fragments and sections and their respective standard errors.

<p>Variance components of the random-effects fragments and sections and their respective standard errors.</p

Representative illustration of the primordial follicular quantification.

<p>Mean primordial follicle densities (number/mm²) of 40 sections per fragment for 20 fragments from the same ovary (A) are shown. An example of the primordial follicle density within serial sections (at a 30-µm distance) of three fragments from the same ovary is also illustrated (a, b and c) (B).</p

Results of the Monte-Carlo simulations.

<p>The probability of detecting an effect on the primordial follicular density (i.e., power) was calculated with the fixed effects arbitrarily set at 50, 25 and 10% and a confidence level of alpha  = 0.05 for various combinations of the numbers of ovary fragments and sections per fragment.</p

Follicle quantification in the whole ovaries.

<p>Follicle quantification in the whole ovaries.</p

Additional file 1: of Supplementation of transport and freezing media with anti-apoptotic drugs improves ovarian cortex survival

Statistical analyses between the different conditions and treatments. Table S1 and Table S2. Primordial follicular density. Table S3 and Table S4. Density of morphologically normal primordial follicules. Table S5. Density of proliferative granulosa cells between treatments. Table S6. Density of global proliferative cells between treatments. (XLSX 38 kb