TTC22 increasing total m6A RNA level and colon cancer metastasis via RPL4-WTAP-YTHDF1 axis

ABSTRACT: WTAP is an essential component of the RNA N-6-methyladenosine (m6A) modification complexes that guides METLL3-METLL14 heteroduplexes to target RNAs in the nucleus of mammalian cells. Through mining the genotype-tissue expression (GTEx) datasets, we initially found that TTC22 expression was highly correlated with WTAP and FTO in many normal human tissues. Our experimental results indicate that TTC22 could directly capture RNA binding protein RPL4, induce the binding between RPL4 and WTAP mRNA in the cytoplasm, which increased the m6A level, induced alterative splicing, enhanced the stability and translation efficiency of WTAP mRNA, and consequently upregulated the level of total m6A RNA. These results indicate that WTAP mRNA is a m6A target and there is a positive feedback loop between total m6A and WTAP expression. YTHDF1 was found to be an essential m6A WTAP mRNA binding protein. Downregulation of RPL4, WTAP, or YTHDF1 expression could reverse TTC22-enhanced total m6A RNA level. m6A-specific antibody immunoprecipitated RNA-sequencing (meRIP-seq) demonstrated that TTC22 caused dramatic expression changes of genes related to metabolic pathways, ribosome biogenesis, and RNA spliceosome. Furthermore, we also found that TTC22 upregulated the expression of epithelial-mesenchymal transition (EMT)-related gene SNAI1 via m6A, and promoted metastasis of colon cancer in vitro and in mice. In conclusion, our study illustrates that WTAP mRNA is a m6A target using YTHDF1 as the binding protein. TTC22 could upregulate the levels of WTAP expression and total m6A RNA through the PRL4 binding. The m6A-mediated upregulation of SNAI1 expression may contribute to TTC22-enhanced colon cancer metastasis.

ORGANISM(S): Homo sapiens

PROVIDER: GSE188521 | GEO | 2024/11/10

REPOSITORIES: GEO