Dataset Information

Small molecule RBI2 disrupts ribosome biogenesis through pre-rRNA depletion

ABSTRACT: In all domains of life, the rate of protein synthesis is directly linked to the rates of cell growth and proliferation. Consequently, highly proliferative cancer cells are especially sensitive to perturbations in ribosome biogenesis. While ribosome synthesis and cancer have a well-established relationship, only recently has ribosome biogenesis drawn interest as a cancer therapeutic target. Here, we have exploited the relationship between ribosome biogenesis and cancer cell proliferation by using a potent ribosome biogenesis inhibitor: RBI2 (Ribosome Biogenesis Inhibitor 2) to perturb cancer cell growth and viability. We demonstrate that RBI2 significantly decreases cell viability in malignant melanoma cells and breast cancer cell lines. Treatment with RBI2 dramatically and rapidly decreases ribosomal RNA (rRNA) synthesis, without affecting the occupancy of RNA polymerase I (Pol I) on the ribosomal DNA template. Next-generation RNA sequencing (RNA-seq) reveals that RBI2 and previously described ribosome biogenesis inhibitor CX-5461 induce distinct changes in the transcriptome. Investigation of the content of the pre-rRNAs through RT-qPCR reveals an increase in polyadenylation of cellular rRNA after treatment with RBI2, a known pathway by which rRNA degradation occurs. Northern blotting revealed that RBI2 does not appear to impair or alter rRNA processing. Collectively, these data suggest that RBI2 inhibits rRNA synthesis distinctly from other previously described ribosome biogenesis inhibitors, potentially through a novel pathway that upregulates turnover of premature rRNAs.

ORGANISM(S): Homo sapiens

PROVIDER: GSE188262 | GEO | 2021/11/08

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Osteoarthritis (OA) is a chronic debilitating joint disease which is strongly associated with ageing. OA involves pathological cellular processes in all joint structures and affects articular cartilage integrity, leading to dysfunctional joint articulation. The biomolecular processes that catalyze the disturbances in the articular chondrocyte phenotype leading to OA are poorly understood, and it is expected that a comprehensive understanding of the avenues leading to catabolic changes and disruption of articular chondrocyte homeostasis will provide important cues for future treatments of the condition. Chondrocytes are specialized secretory cells with highly active protein translational machinery, enabling the synthesis and maintenance of the protein-rich cartilage extracellular matrix (ECM). Disturbances in chondrocyte protein translation in cartilage development and OA are connected to mTOR activity, ER stress, unfolded protein response (UPR)and CHOP-mediated apoptosis. These responses change the downstream translational activity of the biosynthesized ribosome. The assembled mammalian ribosome is built from ribosomal RNAs (rRNAs), together with more than 80 different protein subunits. At the heart of the ribosome, the 18S rRNA guides the decoding of the mRNA message, while an ancient ribozyme activity in the 28S rRNA forms the core of the peptidyltransferase center that polymerizes the amino acid sequence encoded by the mRNA into functional proteins. Post-transcriptional maturation of rRNAs is an integral part of the biosynthesis of ribosomes and ribonucleolytic processing of the major 47S rRNA precursor into mature 18S, 5.8S, and 28S rRNAs is rate limiting for ribosome biogenesis. The U3 small nucleolar RNA (snoRNA) is an evolutionarily highly conserved box C/D-class snoRNA which catalyzes the endoribonucleolytic processing of the 5’ external transcribed spacer (ETS) of the 47S pre-rRNA by base complementarity-guided pre-rRNA substrate recognition and plays a crucial role in the maturation of 18S rRNA. Although extensively studied in yeast, it was only recently demonstrated that U3 snoRNA is indispensable for rRNA maturation in human cells. Pathways controlling ribosome activity have previously been described in the regulation of chondrocyte homeostasis. We here now postulate that not only ribosome activity is involved in chondrocyte homeostasis, but that OA pathophysiological situations can also cause alterations in chondrocyte ribosome biogenesis with consequences for cellular protein translation. Since U3 snoRNA-driven rRNA production is rate-limiting in ribosome biogenesis, we hypothesized that the U3 snoRNA is critical for chondrocyte homeostasis. In this study we therefor aimed to determine whether OA pathophysiological conditions interact with chondrocyte U3 snoRNA levels, thereby influencing rRNA levels and chondrocyte translation capacity.

Dataset Information

Small molecule RBI2 disrupts ribosome biogenesis through pre-rRNA depletion

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure