LAIR-1 suppresses cell growth of ovarian cancer cell via the PI3K-AKT-mTOR pathway.

Recently, over-expression of LAIR-1 has been found in some solid cancers, including ovarian cancer. The role of LAIR-1 in cancer progression needs further investigation. In this study, we identified the LAIR-1 cDNA sequence of the ovarian cancer cells HO8910. Using SKOV3 cells, we confirmed the finding from our previous study that LAIR-1 could suppress in vitro cell proliferation and cell migration. We also found LAIR-1 overexpression can induce apoptosis of SKOV3 cells. We revealed LAIR-1 suppressed cell growth by inhibiting the PI3K-AKT-mTOR axis. Moreover, the LAIR-1 antitumor activity and its mechanism were also identified in vivo. We used Co-IP assay and mass spectrometry to identify potential LAIR-1-binding proteins in LAIR-1 overexpressing SKOV3 cells. MS analysis identified 167 potentially interacting proteins. GO analyses indicated a possible involvement of LAIR-1 in mRNA processing through its interaction with some eukaryotic translation initiation factors (eIF4E1B, eIF2S3, eIF3D, eIF4G2, eIF5B) and eukaryotic translation elongation factors (eEF1A2 and eEF1B2). Our findings suggest that LAIR-1 may suppress the growth of ovarian cancer cells by serving as a modulator that suppresses PI3K-AKT-mTOR directly or regulating protein synthesis at the translational level. Our results indicate that a LAIR-1-based strategy may prevent or suppress the progression of ovarian cancer.