Hormone Control Related Genes in Women With Endometriosis

The development of endometriosis is Estrogen driven

Key Points

Highlight

• The expression level of the estrogen receptor-beta (ERβ), encoded by the ESR2 gene, may have an important role in the pathogenesis of endometriosis.
  

Importance

• Knowing the relationship between ESR2 and CYP19A1 gene expression and endometriosis may help formulate and develop new therapeutic concepts and strategies for this disease.

What is done here?

• The paraffin blocks of two types of tissue specimens from patients with endometriosis (n= 100) and control (n= 100) were examined and compared.
• RNA isolated from 63 endometriomas, 10 cases of abdominal wall endometriosis, 17 peritoneal endometriosis, 10 deeply infiltrating endometriosis, and 100 healthy tissues; were reverse transcribed to cDNA.
• Gene expression of ESR2 and CYP19A1 was quantified using the Real-Time polymerase chain reaction method.

Key results

• The expression of the ESR2 gene is higher in abdominal wall endometriosis nodules compared to healthy control tissues.
• There is no significant difference in the expression of CYP19A1 between two study groups.
• The level of CPY19A1 expression in the group of endometrioma and peritoneal endometriosis is associated with the Revised American Society for Reproductive Medicine stage.

Limitation of the study

• The sample size of the study is small.

Lay Summary

Endometriosis is an estrogen-dependent disease.  The development of endometriosis is stimulated by the specific ability to receive the estrogen that is needed for growth and differentiation of endometrial cells and has numerous biological functions in eutopic and ectopic endometrium.

Estrogen is produced from testosterone and androstenedione by the action of enzyme P450 cytochrome aromatase, which is the product of the gene CYP19A1 gene.  The target cells can receive estrogen through estrogen receptors, ERα and ERβ encoded by the genes ESR1 and ESR2, respectively. Among the two receptors, ERβ is the main estrogen receptor in patients with endometriosis. ERS2 and CYP19A1 genes are important in the regulation of hormones in women with endometriosis.

This study aimed to assess gene expressions of estrogen receptor (ESR2) and cytochrome P450 family member (CYP19A1) in the framework of the risk for endometriosis.  

The gene expression of ESR2 and CYP19A1 was quantified in patients with several types of endometriosis, and healthy controls. Moreover, the relationship between gene expressions and the prevalence of endometriosis among Polish women was determined.

The study demonstrated a significant increase of ESR2 gene expression in the group of women with endometriosis, indicating a role in its pathogenesis. The ERS2 gene expression was found to be higher in the endometriosis nodules of the abdominal wall, reflecting a significant role of the ESR2 gene in the pathogenesis of abdominal wall endometriosis. Even though there was no significant difference in the expression of CYP19A1 between the groups of endometriosis and controls, the expression levels of the CYP19A1 gene were associated with the revised ASRM clinical staging of the patients.

The authors of this study, lead by Szaflik et al., suggested that the reduction of CYP19A1 gene expression resulted from epigenetic modification in the regulatory regions of the gene. Demethylation of the CpG islands in the CYP19A1 gene may be important in the regulation of aromatase levels. 

Although there are only a few studies on the expression of CYP19A1 and ESR2  genes in patients with endometriosis, the findings from the study contribute to a broader knowledge of the effects of genetic factors and information on the molecular mechanisms on the development of endometriosis. In knowing the relationship between ESR2 and CYP19A1 gene expression and endometriosis, it may help design and develop new therapeutic concepts and strategies for the disease.

The article is published in the journal named "InVivo-International Journal of Experimental and Clinical Pathophysiology and Drug Research" recently.

Research Source: https://pubmed.ncbi.nlm.nih.gov/32606145/