Membrane vesicles in ovarian cancer fluids: A new potential marker

The rate of membrane vesicle shedding by tumor cells is probably related to their invasive capability. In order to verify whether the vesicle amount c ould be utilized as a marker of different pathologies, we analyzed biologic al fluids obtained from 33 patients with gynecological diseases. In fluids of benign serous cysts, vesicle content was extremely low; in cystoadenomas and fibromas generally it was low. On the contrary, large amounts of vesic les were found in malignant tumor fluids. Gelatin zymographies showed the p resence of MMP-2 and MMP-9 in all vesicles except in those recovered from f luids of some serous cysts. A positive correlation between tumor malignancy and both vesicle-amount and vesicle-associated MMP-2 activity was noticed. We also analyzed vesicle content in ascitic fluids recovered from two carc inomas at different times during clinical treatment. In both cases, tumor p rogression, not monitored by Ca 125 levels, was pointed out by an increased amount of vesicles in ascites. These findings suggest that vesicle content in biological fluids could represent a new useful marker of tumor aggressi veness and tumor progression.