OBJECTIVETo investigate the value of serum miR-17-92 cluster in the diagnosis of retinoblastoma (RB).

METHODSSerum samples were collected from 20 children with RB and 20 healthy controls. Quantitative real-time PCR was used to measure the expression of miR-17-92 cluster. The expression of miR-17-92 cluster was compared between children with different stages of RB and the changes in the expression of miR-17-92 cluster after multimodality therapy were analyzed. The receiver operating characteristic (ROC) curve was used to investigate the value of serum miR-17-92 cluster in the diagnosis of RB.

RESULTSCompared with the healthy controls, the children with RB had significantly higher relative expression of miR-17-3P, miR-17-5P, miR-18a, and miR-20a in serum (P<0.05), and miR-18a showed the greatest increase. There were no significant differences in the relative expression of miR-19a, miR-19b-1, and miR-92a-1 between children with RB and healthy controls (P>0.05). There were no significant differences in the expression of miR-17-5P, miR-17-3P, miR-18a, and miR-20a between the children with early-to-moderate stage of RB and those with advanced stage of RB (P>0.05), but there were significant reductions after multimodality therapy (P<0.05). In the diagnosis of RB, the areas under the ROC curve (AUCs) for serum miR-17-3P, miR-17-5P, miR-18a, and miR-20a were 0.770, 0.755, 0.828, and 0.665 respectively, and miR-18a had the largest AUC, with a sensitivity of 90% and a specificity of 65%.

CONCLUSIONSmiR-17-3P, miR-17-5P, miR-18a, and miR-20a are highly expressed in the serum of children with RB, and miR-18a may be used as a new marker for the diagnosis of RB.