USP13 Regulates the Breast Tumor Proliferation and Migration through the Stabilization of PDCD4 Protein

Background: Programmed cell death protein 4 (PDCD4), which serves as a tumor suppressor protein, plays a important role in cell proliferation,apoptosis, cell migration and DNA-damage response.However, the exact mechanism for the deubiquitination of PDCD4 remain unclear. Methods: : Western blotting was used to detect the expression of PDCD4 in the breast cancer tissues and BC cell lines. We identified the potential PDCD4 associated deubiquitinase by RNAi screening. GST-Pull down and domain-mapping analysis were used to reveal that USP13 and PDCD4 directly interact with each other.Flow cytometry was used to detect the changes of G1 to S phase. Soft agar assay was used to measure the changes of the cell proliferation efficiency. Results: : The expression of PDCD4 was decreased in the breast cancer tissues and BC cell lines. USP13 as a potential PDCD4 associated deubiquitinase. USP13 physically interacted with PDCD4 and greatly increased the steady state of PDCD4 through the ubiquitin-proteasome pathway.Importantly, silencing of the USP13 facilitated cell cycle from G1 to Sphase, promoted breast tumor cells proliferation and migration through downregulation of PDCD4. Conclusions: : Together, these results suggest that USP13 plays an important role in the breast tumor proliferation and migration through modulating PDCD4 stability.