The Critical Role Of Circular RNA In CM And NB Tumorigenesis

Objectives: Conjunctival melanoma(Conjunctival Melanoma,CM)is a rare but fatal ocular malignant tumor with high blindness rate and mortality,which seriously affects patients’ quality of life and life safety.At present,the basic research of CM mainly focuses on DNA levels such as mutations and deletions of genes,and few scholars pay attention to the epigenetic mechanism of CM pathogenesis.Circular RNA(circRNA)is an important emerging member of epigenetics in recent years,and it plays various regulatory roles in tumorigenesis.This study focused on circRNA-related research and analysis of CM.Materials and methods: For patients with clinical diagnosis of CM,CM tissue specimens and adjacent tissues were obtained by surgical resection,and deep sequencing of circRNA was performed,and the sequencing results were analyzed.Specifically expressed circRNAs were selected based on the analysis results.The loop-forming properties of circRNA were identified by actinomycin D treatment,RNase R digestion and first-generation sequencing.Effects of circRNA on phenotype of CM cells were measured by CM stable cell lines,CCK8 assay,plate colony formation assay,soft agar colony formation assay and subcutaneous tumor formation assay.The downstream exploration of circRNA was carried out by RIP experiment and bioinformatics.Results: Deep sequencing of circRNA in CM tissues and adjacent tissues identified mutiple dysregulated circRNAs.CircMTUS1 was highly expressed in patient tissues and CM cell lines.Knockdown of circMTUS1 could significantly inhibit the growth and proliferation of CM cell lines in vivo and in vitro.The downstream of CircMTUS1 might be hsa-miR-622 and hsa-miR-1208,and circMTUS1 might act miRNA sponge to regulate the expression of target genes.Conclusions: CircMTUS1 was a circular RNA and was highly upregulated in CM.CircMTUS1 might act as an oncogene by sponging hsa-miR-1208 of hsa-miR-622.Objectives: Neuroblastoma is the most common extracranial solid tumor in children and has a high degree of malignancy.The cause of neuroblastoma is not known at present,but studies have reported that non-coding RNA plays an important role in it.Circular RNA is a kind of non-coding RNA that has been studied in recent years and circHIPK3 has been confirmed to be enriched in the nervous system such as brain and involved in the occurrence and progression of various malignant tumors.This study focused on the role of circHIPK3,a neuronal enriched circular RNA,in neuroblastoma.Materials and methods: CircHIPK3 was identified as a circular RNA in neuroblastoma by means of actinomycin D,RNase R and sequencing.The expression of circHIPK3 was detected in neuroblastoma specimens.The neuroblastoma circHIPK3 stable cell lines were established,and the biological effects of circHIPK3 on neuroblastoma were studied by CCK8 assay and transwell assay.Bioinformatics,luciferase reporter gene assay and RNA pull down verify the binding of circHIPK3 to downstream miR-637.The rescue experiment further validated the relationship between circHIPK3 and miR-637.Bioinformatics,luciferase reporter gene assay and RNA pull down assay verified the binding of circHIPK3 to downstream miR-637.The rescue experiment further validated the relationship between circHIPK3 and miR-637.The western blot experiments verified the effect of circHIPK3 on the downstream AKT1 protein of miR-637.Results: circHIPK3 is a circular RNA in neuroblastoma and is in a high expression state.Knockdown of circHIPK3 significantly inhibited proliferation,colony formation and migration of neuroblastoma cells.MiR-637 binds to circHIPK3 in neuroblastoma and affects downstream AKT1 expression.Conclusions: CircHIPK3 is highly expressed in neuroblastoma and acts as an oncogene.CircHIPK3 acts as an sponge of miR-637 to affect downstream AKT1 expression and thus promoting cancer progression in neuroblastoma.