circZC3HAV1 Regulates TBC1D9 to Affect the Biological Behavior of Colorectal Cancer Cells.

Background: Colorectal cancer (CRC) is one of the most frequently diagnosed cancers all over the world, which accounts for a large proportion of cancer-associated deaths. The regulatory function of circular RNAs (circRNAs) has been affirmed in diverse cancers. circ_0082628, named circRNA zinc finger CCCH-type containing antiviral 1 (circZC3HAV1), has been discovered to be significantly downregulated in CRC tissues. Nevertheless, the function and mechanism of circZC3HAV1 in CRC remain unclear.

Purpose: We targeted at studying the specific role and mechanism of circZC3HAV1 in CRC cells.

Methods: The expression of the genes was detected by quantitative real-time polymerase chain reaction (qPCR). The binding relationship among different genes was verified by mechanism assays. Functional assays were carried out to reveal the role of different RNAs in CRC cell malignant behaviors.

Results: circZC3HAV1 was significantly downregulated in CRC cells. circZC3HAV1 overexpression hampered CRC cell migratory and invasive abilities. As for the mechanism, circZC3HAV1 competitively bound with microRNA-146b-3p (miR-146b-3p) to enhance the expression of TBC1 domain family member 9 (TBC1D9). Rescue assays demonstrated circZC3HAV1 sponged miR-146b-3p and upregulated TBC1D9 to restrict migration and invasion of CRC cells.

Conclusion: circZC3HAV1 could upregulate TBC1D9 via absorbing miR-146b-3p, consequently inhibiting migratory and invasive capabilities of CRC cells.