Long Non-coding RNA CBR3 Antisense RNA 1 is Downregulated in Colorectal Cancer and Inhibits miR-29a-Mediated Cell Migration and Invasion.

Although CBR3 Antisense RNA 1 (CBR3-AS1) has been characterized as an oncogenic long non-coding RNA (lncRNA) in several cancers, a recent study reported the downregulation of CBR3-AS1 in colorectal cancer (CRC). Therefore, we analyzed its role in CRC. CBR3-AS1 and microRNA-29a (miR-29a) expression in tissue samples from CRC patients were analyzed by RT-qPCR. The interaction between CBR3-AS1 and miR-29a was predicted by IntaRNA and validated by RNA pull-down assay. The location of CBR3-AS1 was analyzed by nuclear fractionation assay. CBR3-AS1 overexpression was performed to analyze its role in miR-29a expression. The roles of CBR3-AS1 and miR-29a in CRC cell migration and invasion were analyzed by Transwell assay. CBR3-AS1 was downregulated, and miR-29a was upregulated in CRC. CBR3-AS1 and miR-29a directly interacted with each other. CBR3-AS1 was localized in both nucleus and cytoplasm fractions. CBR3-AS1 overexpression failed to alter miR-29a expression but reduced its enhancing effects on cell invasion and migration. CBR3-AS1 is downregulated in CRC and inhibits miR-29a-mediated cell migration and invasion by sponging miR-29a.