Objective: MicroRNAs are short, noncoding RNA molecules that negatively regulate the stability and translational efficiency of target mRNAs. They are critical regulators of growth and development. Our aim was to identify microRNAs involved in the growth and regulation of infantile hemangiomas. In addition, we searched for the presence of Piwi-interacting RNAs in hemangioma tissue as another regulator of infantile hemangiomas. Methods: RNA was extracted from hemangioma specimens from 3 clinical, age-based categories: proliferative (N = 16), quiescent (N = 8), and involuting (N = 9). RNAs from human dermal microvascular endothelial cells were used as controls. MicroRNA microarray was performed, and the expression profiles of the hemangiomas and endothelial cells were compared using the t test. 5' End-labeling of RNA of our hemangioma specimens was performed for Piwi-interacting RNA detection. Results: Analysis confirmed statistically significant downregulated (N = 18) and upregulated (N = 15) microRNAs. Piwi-interacting RNA analysis did not detect Piwi-interacting RNA transcripts in the hemangioma specimens. Conclusions: The differential expression of microRNAs found in our hemangioma specimens provides insight into the regulation of hemangioma formation and proliferation, quiescence, and fibrofatty involution. Piwi-interacting RNA transcripts were not detected in the hemangioma specimens. These novel findings will help in establishing new therapeutic and diagnostic initiatives for these tumors.
Keywords: Piwi-interacting RNA; infantile hemangioma; miRNA; microRNA; microarray profiling.