Emerging role of circular RNAs in the pathogenesis of retinoblastoma

Retinoblastoma (Rb) accounts for 3% of all childhood cancers. It is the most common intraocular malignant tumor with a highly aggressive and metastatic phenotype. Gaining a more comprehensive understanding of the molecular mechanisms underlying the proliferation, metastasis, migration, invasive apoptosis, and autophagy processes associated with this cancer would facilitate the design of therapeutic modalities and the identification of novel tumor markers. Recent investigations have shown the contribution of circular RNAs (circRNAs) in the evolution of Rb. Several circRNAs, including circ_0000034, circ_0000527, circ_0075804, circ_0099198, circFAM158A, and circVAPA, promote the progression and metastasis of Rb. However, some circRNAs, such as circ_0001649, circMKLN1, and circTET1, play a tumor suppressive role. In this regard, circRNAs can regulate cancer-developing processes including cell proliferation, apoptosis, migration, invasion, and tumor growth. This review summarizes the functional roles of circRNAs in Rb and their potential clinical applications for diagnosis and prognosis, and provides a comprehensive understanding of the role of circRNAs in the pathophysiology of Rb.