Clinical Impact of Down-Regulated Plasma miR-92a Levels in Non-Hodgkin's Lymphoma

BACKGROUND: We undertook a study to evaluate the clinical relevance of miR-92a in plasma obtained from non-Hodgkin's lymphoma (NHL) patients, because the miR-17-92 polycistronic miRNA cluster plays a crucial role in lymphomagenesis and affects neo-angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Plasma miR-92a values in NHL were extremely low (<5%), compared with healthy subjects (P<.0001), irrespective of lymphoma sub-type. The very low plasma level of miR-92a increased in the complete response (CR) phase but did not reach the normal range, and the plasma level was lower again in the relapse phase. Patients in CR or CR unconfirmed with a plasma miR-92a level of less than the cut-off level showed a significantly high relapse rate compared with patients with normalized plasma miR-92a level. CONCLUSIONS/SIGNIFICANCE: The current results therefore indicate that the plasma miR-92a value could be a novel biomarker not only for diagnosis but also for monitoring lymphoma patients after chemotherapy.