Toward an understanding of cancer-associated ribosomal protein mutations

Ribosomal proteins (RPs) are essential structural and functional components of the ribosome, and their disruption during embryogenesis generally results in embryonic lethality. Nevertheless, cancer genomes frequently harbor somatic missense mutations and gene deletions in RP genes in patterns that suggest selective advantages, often linked to inactivation of the tumor suppressor protein p53 pathway. This review discusses the landscape of RP mutations in cancer and their mechanistic consequences. RP mutations are detected across multiple malignancies, including glioblastoma, melanoma, T-cell acute lymphoblastic leukemia, as well as in congenital ribosomopathies, such as Diamond-Blackfan anemia, which confer an elevated lifetime risk of developing cancer. Cancer-associated RP mutations disturb ribosome homeostasis, compromise translational fidelity, and trigger proteotoxic and ribosomal stress, yet without halting tumor growth. Some RP mutants occupy structurally sensitive positions within the ribosome, altering mRNA selectivity and quality control. In turn, cancer cells may adapt through compensatory mechanisms, including the upregulation of RP paralogs, activation of proteostasis regulators, and rewiring of stress response pathways. Rather than a loss-of-function event, an RP mutation may create a persistent ribosomal disequilibrium that fundamentally alters cellular functions. Such changes in a cancer cell could generate interesting therapeutic vulnerabilities and targets, such as dependence on stress signaling, proteasome activity, or RP paralog expression.