Circ_0001461 Regulates Colorectal Cancer Growth, Movement and Immune Escape Through miR-532-3p/AMOTL2.

Abstract

Colorectal cancer (CRC), as a common malignant tumor of gastrointestinal tract, has become one of the important diseases threatening human health. Circ_0001461 has been proven to be closely associated with the occurrence and development of various cancers. This study explored the function and possible mechanism of circ_0001461 in CRC. The RNA expression level was detected using qRT-PCR. The viability, apoptosis or invasion ability of CRC cells were explored by CCK-8, flow cytometry or Transwell experiment, respectively. The protein expression level in cells was analyzed by Western blot (WB). IFN-γ, IL-2 or TNF-α levels were investigated via ELISA experiment. The targeting relationship between circ_0001461, miR-532-3p and AMOTL2 was confirmed via dual-luciferase reporter experiment, RNA pull-down experiment and RIP assay. The protein expression in tissues was explored by IHC staining. Tumor volumes, body weights, tumor weights and apoptosis levels were detected in xenograft mouse model. Circ_0001461 was greatly expressed in CRC samples and was associated with poor prognosis. Silencing circ_0001461 reduced cell proliferation, increased cell apoptosis rate, decreased invasion ability and inhibited immune escape in vitro. Additionally, silencing circ_0001461 prominently shortened the tumor volume and tumor weight in vivo. Circ_0001461 targeted miR-532-3p to regulate AMOTL2 expression. AMOTL2 was the downstream targets of miR-532-3p. Downregulation of miR-532-3p or overexpression of AMOTL2 abolished the effect of silencing circ_0001461. Collectively, our research demonstrated that the circ_0001461 played a certain regulatory role in growth, movement and immune escape of colon cancer via miR-532-3p/AMOTL2 axis.