Women with endometriosis may experience different genetic and chemical changes in the uterine cells that may be influenced by hormonal fluctuations when compared with those who do not have the condition, new research finds.
Endometriosis is a chronic and painful disease that affects around one-in-10 women. The condition occurs when tissue that normally grows inside of the uterus – the endometrium – begins to grow in other places, most commonly the ovaries and fallopian tubes, according to the Mayo Clinic. Its exact cause is unknown and treatments have varying degrees of success, positioning the common condition as a priority for many reproductive researchers and gynecologists.
“The findings raise the possibility that differences in methylation patterns could one day be used to diagnose endometriosis and develop customized treatment plans for patients,” said Stuart B. Moss, PhD, of the National Institute of Child Health and Human Development's Fertility and Infertility Branch, in a statement.
To determine how endometriosis may influence an individual’s genetic properties, the researchers compared DNA methylation in both the uterine cells and in other parts of the body. DNA methylation is the binding of compounds, or methyl groups, to DNA and can alter gene activity as well as contribute to important processes within the body, including embryonic development and the turning “off” of certain gene signals, notes Nature. Methylation was compared in both women with endometriosis and those with no gynecological disorders.
Certain hormones are known to regulate genes in select tissues, including the lining of the uterus. The researchers also analyzed how methylation patterns and gene function responded to two hormones important to the female reproductive system: progesterone and a form of estrogen known as estradiol. Test subjects were given each hormone independently and again in combination.
Methylated regions of the uterine cells were shown to vary depending on the stage or severity of a person’s endometriosis – the condition is evaluated in four stages, from mild to severe. DNA methylation and gene functioning were also shown to respond differently when exposed to the hormones, both individually and when they were given in combined doses. Because the type of methylation varies depending on the stage of endometriosis, the study authors conclude that there may be two subtypes of the disease rather than just degrees.
Though the researchers note their small sample size as a limitation, they add that the findings reveal unique responses and pre-existing abnormalities in women with endometriosis and can help to inform future therapies and treatments.