It is not easy being a cancer cell, so such cells may need help from factors other than oncogenes that contribute to the cancer cell phenotype. Bublik et al. identify such a factor in protein fibroblast growth factor 13 (FGF13). FGF13 does not function like a regular growth factor. Instead, it acts in the nucleolus to repress transcription of ribosomal RNA and inhibit protein synthesis. Furthermore, it is tightly linked to the action of the tumor suppressor p53. The p53 protein inhibits expression of the FGF13 gene, which also encodes a microRNA that in turn down-regulates p53, forming a negative feedback loop. FGF13 may help cancer cells avoid the toxic effects of excessive protein synthesis and could therefore be targeted for cancer therapy.
