Increased levels of biglycan in endometriomas and peritoneal fluid samples from ovarian endometriosis patients.

In our previous low-density-array gene-expression analysis we found an increased expression of biglycan gene in ovarian endometriosis patients. In the present study we evaluated biglycan expression at the protein level in tissue, serum and peritoneal fluid (PF) from ovarian endometriosis patients, patients with benign ovarian cysts and healthy women. Twenty samples of endometriomas and 27 of control tissues (benign ovarian cysts and eutopic endometrium of healthy women) were obtained laparoscopically or by curettage. Serum and PF samples were collected from 56 ovarian endometriosis patients and 40 controls (patients with benign cysts and healthy women). Tissue biglycan levels and serum and PF biglycan concentrations were determined by Western blotting and ELISA, respectively. Biglycan was detected in endometriomas and in benign cysts tissues but differed in glycosylation levels. The PF biglycan concentrations were significantly increased in ovarian endometriosis patients (mean ± SD=220.3 ± 190.5 pg/mg protein) compared to the whole control group (101.9 ± 94.7 pg/mg protein, p<0.001), while serum concentrations did not differ significantly. Biglycan appears to be involved in ovarian pathologies and probably has different roles in benign cysts as compared to ovarian endometriomas.