Apoptosis in normal ovaries of women with and without endometriosis

The aim of this study was to evaluate the factors predisposing to implants of endometriotic lesions in normal ovarian cortexes of women with and without endometriosis by assessing the expression of pro-apoptotic and anti-apoptotic factors and follicular density. Ovarian biopsies were performed during laparoscopy in 18 patients with endometrioma and in 10 healthy women. Detection of apoptosis was performed with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling assay. p53 and BCL2 proteins were assessed by immunohistochemistry. Quantitative real-time polymerase chain reaction was performed to evaluate BAX, BAK, BCL2, BCL-XL, survivin and β-actin (ACTB) expression. The p53 protein was positive in a significantly higher number of secondary follicles, whereas the B-cell chronic lymphocytic leukaemia/lymphoma 2 (BCL2) protein was positive in all follicles in unaffected tissue of endometriotic women, compared with the controls. Overexpression of the BCL2 and survivin genes and a decreased BAX and BAK gene expression were observed in the endometriotic group although only the difference in survivin expression was significant (P = 0.016). The BCL2/BAX ratio showed an increased value in the ovarian cortex in controls compared with endometriosis patients. In conclusion, the reduction of apoptosis in unaffected tissue in women with endometriosis suggests that they may be predisposed to develop endometriosis.