Abstract
VPS33B is reported to be a tumor suppressor in hepatocellular carcinoma, nasopharyngeal carcinoma, colon cancer, and lung adenocarcinoma. Here, we observed that reduced VPS33B protein level was an unfavorable factor that promoted the pathogenesis of non-small cell lung cancer (NSCLC) in clinical specimens. We achieved lentivirus-mediated stable overexpression of VPS33B in NSCLC cells. Increased VPS33B reduced cell cycle transition and cell proliferation of NSCLC cells in vivo and in vitro. Knocking down VPS33B restored cell growth. Mechanism analysis indicated that miR-192-3p was induced by VPS33B and acted as a tumor suppressor of cell growth in NSCLC. Further, c-Myc or p53 was identified as a transcription factor that bound to the miR-192-3p promoter and regulated its expression. miR-192-3p directly targeted cell cycle-promoted factor CCNB1 and suppressed NSCLC cell growth. VPS33B modulated c-Myc/p53/miR-192-3p signaling to target CCNB1 by reducing activation of the Ras/ERK pathway. Our study reveals a novel molecular basis for VPS33B as a tumor suppressor to participate in the pathogenesis of NSCLC.