Rrp8, or ribosomal RNA processing 8, is a nucleolar Rossman fold-like methyltransferase involved in RNA modification, specifically the N1-methyladenosine (m1A) modification of ribosomal RNA [3,4]. It has been associated with ribosome biogenesis pathways and is crucial for maintaining normal cellular function. Genetic models like Caenorhabditis elegans have been used to study its role in rRNA modification [3].

In hepatocellular carcinoma (HCC), both knockdown and knockout of Rrp8 in functional studies significantly attenuated the proliferation and migration of liver cancer cells. Knockout of Rrp8 decreased the phosphorylation of MEK1/2 and β-catenin-(Y654) signalling pathway components, downregulated downstream signalling effectors such as Cyclin D1 and N-cadherin, and upregulated E-cadherin. Also, Rrp8 was strongly associated with immune infiltration and an unfavourable prognosis in HCC [1]. In podocytes, loss of Profilin1 led to downregulation of Rrp8, resulting in mitotic catastrophe. Overexpression of Rrp8 in Pfn1-KO podocytes partially rescued the phenotype in vitro [2].

In conclusion, Rrp8 is essential for RNA modification and ribosome biogenesis. Its study through gene knockout models has revealed its significance in cancer, especially HCC, where it is associated with immune infiltration, prognosis, and cancer cell proliferation and migration. In kidney diseases, it is involved in maintaining podocyte integrity. These findings provide potential therapeutic targets for related diseases.