Scientists may be one step closer to solving the mystery behind endometriosis — what doctors say is a common health problem for women. In their latest study, scientists at the University of Liverpool in the UK have discovered what may be triggering this condition. Their findings were recently published in the journal Human Reproduction.
'Endometriosis occurs when cells of the inner lining of the womb are found growing outside of the uterus,' explained Dr Dharani Hapangama from the Department of Reproductive and Developmental Medicine, University of Liverpool. 'At the time of a woman's menstruation cycle these cells, called endometrial cells, are shed and can be expelled into the abdominal cavity,' he said. 'If these cells continue to live and are implanted in the pelvis and abdomen it can cause severe pain and in serious cases can lead to infertility.'
The telomerase enzyme, found in cells and the inner lining of the womb, patrols the end parts of chromosomes, called telomeres. These telomeres hold the two ends of the chromosomes together and ensure that they stay intact during cell division. The researchers found that telomerase is released by cells in the inner lining of the womb at the beginning and towards the end of the menstrual cycle in women suffering from this condition. Cancer cells also contain this enzyme, which seemingly replicates DNA sequences during cell division in chromosomes, experts say.
The lead researcher went on to say that the team found the telomere to be unusually long in women with endometriosis. 'During menstruation, telomeres normally shorten in length with each cycle of cell division until they reach a certain length at which they can no longer divide,' Dr Hapangama commented. 'The enzyme can extend the length of the telomeres so that they can continue to divide and this can happen in some special cells, such as sperm and egg cells, but not normally in cells that make up the organs of the body.'
'Women who have endometriosis express this enzyme in both the early and late stages of the menstrual cycle which means that the cells will continue to divide and lose their "focus" in supporting the establishment of a pregnancy,' he said. Due to this, the womb's lining 'may be more hostile to an early pregnancy', Dr Hapangama explained. 'The cells that are shed at this late stage in the menstrual cycle may be more "aggressive" and more able to survive and implant outside the uterus, causing pain in the pelvic or abdomen area.'
In general, endometriosis emerges in the lower region of the female pelvis causing extreme pain and discomfort. Around 50% of the cases involve the ovary, and the condition is also responsible for half of the infertility cases.
More than 88 million women worldwide are affected by endometriosis. While the condition affects around 15% of women of reproductive age, up to 4% of the cases are diagnosed in the postmenopausal period.