Ribosomal Proteins and Cancer

Abstract

The translation process consists of translation factors and ribosomes. Ribosomal components include ribosomal proteins (RP) and ribosomal RNA. Many RPs are involved in assembling ribosomal particles and or stabilizing important regions of rRNA. Besides their conventional roles, RPs have been reported to exhibit secondary functions that have not yet been fully characterized in other cellular processes such as DNA repair, apoptosis, drug resistance, proliferation, and growth inhibition. Since cancer cells require a large amount of protein, they need ribosomes that work much more efficiently than normal cells. Several tumor suppressors and oncogenic proteins control the progression of cancer cells by regulating ribosome biogenesis and protein synthesis. Interestingly, free RPs also have diverse roles in tumorigenesis or tumor suppression. The physiological link between RPs and cancers has been extensively reviewed and elucidated on several pathways, including their interaction with the p53-MDM2 complex. The first evidence of an association between RPs and cancer came from observing the haploinsufficiency of eS4 in Turner Syndrome and eS19 mutation in Diamond-Blackfan Anemia. In the following years, the roles of different RPs in various cancer types such as colorectal cancer, breast cancer, lung adenocarcinoma, T-cell acute lymphoblastic leukemia, prostate cancer, breast cancer, gastric carcinomas, ovarian cancer, and liver cancer have been the subject of research. Apart from their effects on carcinogenesis, it was also emphasized that RPs could be evaluated as predictive biomarkers for diagnosis, prognosis, and treatment for some cancer types. In addition, some studies have been conducted on the use of these proteins in cancer treatment. Identifying novel extra-ribosomal functions of some RPs has identified these proteins as a new class of oncogenic or tumor suppressor factors. Suppression and stimulation of the expression of these novel oncogenic and tumor suppressor proteins, respectively, are considered could open up new therapeutic strategies in cancer therapy.