Endometriosis is a condition where the uterine inner layer, endometrium, is found in pelvic cavity and/or in ovaries or on the surface of bladder or rectum. The prevalence of disease in women in their reproductive age is 2-10%, and up to 50% in women with unsolved infertility and/or pain symptoms. Women with endometriosis suffer from chronic pelvic pain caused by innervation and inflammation at locations of endometriotic lesions. Diagnosis is an invasive procedure and treatments are not always effective or bring up severe side effects and, therefore, new information on possible therapeutic targets and diagnosis for endometriosis are essential. The complexity of different types of endometriosis as well as heterogeneous nature of endometrium tissue along its modulation with menstrual cycle makes disease difficult to study in the lab.
The work described in the lecture discusses how a phased mass spectrometry-based approach for discovery, screening, and validation of protein biomarkers with diagnostic value was followed. Technically the workflow was optimized in terms of sample sensitivity and robustness, allowing quantification of several 1000 proteins with a technical CV of 10 % in 10s of patient tissue types. For quantitative analysis, several different approaches were studied including five statistical methods that were evaluated for use with label-free quantitative proteomics data.
Initially we characterized and reported high quality SRM transitions for 168 disease markers, that were then subsequently screened and reduced to a single assay containing 93 synthetic peptides that are currently being used in a multiplexed SRM and SWATH analysis in 100 serum samples from patients. Methods established, study setup and our most recent findings on our MS analysis will be reported.