We are developing uniqe prostate cancer test, based on measuring the ammount of urine exosomal proteins

Developing reliable blood or urine biomarkers for prostate cancer (PCa), particularly to improve early detection of aggressive disease as well as identifying new targets for efficient follow-up therapies, will ultimately lead to better patient survival.  Currently, the most commonly used serum biomarker for prostate cancer is prostate specific antigen (PSA). Additionally, detection of the non-coding RNA PCA3 in urine, a-methylacyl-CoA racemase (AMACR), and the TMPRSS2-ERG fusion are suggested to be useful.  However, each of these biomarkers has well described limitations in their clinical use.   

 Emerging sources for new biomarker candidates of prostate cancer, and all cancer types, have focused on use of a family of tumor-derived membranous extraceullar microvesicles, also generically called exosomes. Exosomes and microvesicles are small membrane vesicles secreted into the extracellular environment by various cell types and contain a broad array of biologically active material, e.g. proteins, mRNA, depending on the cell type and origin. Several cellular components of the tumor microenvironment and cancer cells secrete exosomes that function in an autocrine or paracrine manner to promote tumor-induced immune suppression, angiogenesis, and premetastatic niche formation.  A major function of the prostate gland is the production and secretion of exosomes, also called prostasomes, as a reproductive component of seminal fluids. Multiple studies have shown that prostate-derived microvesicles can be isolated from cells, plasma, urine, and human tissues and could represent a novel biomarker source.