TRIM25 promotes glioblastoma cell growth and invasion via regulation of the PRMT1/c-MYC pathway by targeting the splicing factor NONO
Ubiquitination plays an important role in proliferating and invasive characteristic of glioblastoma (GBM), similar to many other cancers. Tripartite motif 25 (TRIM25) is a member of the TRIM family of proteins, which are involved in tumorigenesis through substrate ubiquitination. Here, we found TRIM25 is upregulated in GBM and promotes glioblastoma cell growth and invasion, both in vitro and in vivo. Subsequently, we screened a panel of proteins that interact with TRIM25; mass spectrometry and co-immunoprecipitation showed that NONO was a potential substrate of TRIM25. TRIM25 knockdown reduced the K63-linked ubiquitination of NONO, which suppressed the splicing function of NONO. The dysfunctional NONO further leads to the retention of the second intron in the pre-mRNA of PRMT1 and inhibit the activation of the PRMT1/c-MYC pathway. In summary, we demonstrated that TRIM25 promotes glioblastoma cell growth and invasion by regulating the PRMT1/c-MYC pathway through mediation of the splicing factor NONO. Efforts to target the E3 ligase activity of TRIM25 or the complex interactions between TRIM25 and NONO may be useful in the treatment of GBM. Overall design: Comparative gene expression profiling analysis of RNA-seq data for LN229 cells and its KD derivatives (shTRIM25).