Silencing eL31 suppresses the progression of colorectal cancer via targeting DEPDC1.

Background: Colorectal cancer (CRC) is one of the most commonly diagnosed human malignancies. Ribosomal protein L31 (RPL31, aka eL31) is a component of the 60S large ribosomal subunit, and its expression pattern and functional role in CRC have not been reported.

Methods: Herein, we identified that eL31 protein level was dramatically increased in CRC tissues through using IHC analysis. More notably, elevated eL31 was associated with larger tumor size and shorter overall survival. Besides, we evaluated the effects of eL31 depletion on CRC cell phenotypes in vitro.

Results: The data indicated that eL31 knockdown restricted CRC cell proliferation, migration and colony formation whilst enhancing cell apoptosis. Importantly, eL31 was also essential for CRC tumor growth in vivo, as demonstrated by impaired tumor growth markers and reduced Ki67 levels in xenografts from eL31-depleted cells. In addition, our evidence indicated that DEP domain containing 1 (DEPDC1) was a potential downstream target of eL31 in regulating CRC. Consistently, DEPDC1 depletion restrained CRC cell proliferation and migration, as well as facilitated cell apoptosis. More interestingly, DEPDC1 depletion could reverse the promotion effects of eL31 elevation on CRC cells.

Conclusions: Identification of eL31's function in CRC may pave the way for future development of more specific and more effective targeted therapy strategies against CRC.