Propofol suppresses colorectal cancer development by the circ-PABPN1/miR-638/SRSF1 axis

Propofol has recently been attracted increasing attention for its anti-tumor property in cancers, including colorectal cancer (CRC). However, the anti-tumor molecular determinants of propofol largely remain to be elucidated.

The levels of circRNA poly(A) binding protein nuclear 1 (circ-PABPN1, hsa_circ_0031288), microRNA (miRNA)-638 and serine and arginine-rich factor 1 (SRSF1) were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell viability, colony formation, apoptosis, invasion, and migration were detected by the Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, transwell, and wound-healing assays, respectively. Animal studies were used to evaluate the biological action of circ-PABPN1 in the propofol-mediated anti-CRC effect. Targeted relationships among circ-PABPN1, miR-638 and SRSF1 were validated by dual-luciferase reporter assays.

Our data showed the anti-tumor activity of propofol in CRC, as evidenced by the repression in cell viability, colony formation, invasion, migration and the promotion in cell apoptosis in vitro, as well as the suppression in tumor growth in vivo. Circ-PABPN1 was overexpressed in CRC tissues and cells, and propofol down-regulated circ-PABPN1 in a dose-dependent manner. Moreover, circ-PABPN1 was a functional effector of propofol in suppressing CRC development in vitro and in vivo. Circ-PABPN1 directly targeted miR-638, and SRSF1 was a direct target of miR-638. Propofol repressed CRC development in vitro by up-regulating miR-638 or down-regulating SRSF1. Furthermore, propofol regulated SRSF1 expression by the circ-PABPN1/miR-638 axis in CRC cells.

Our current findings identified the circ-PABPN1/miR-638/SRSF1 axis as a novel anti-tumor mechanism of propofol in CRC, providing a new rationale for developing propofol as a promising therapeutic agent for CRC.