bioRxiv Science⌕ Search

bioRxiv · 10.1101/2021.12.03.471189

Glutamine deficiency in solid tumors confers resistance to ribosomal RNA synthesis inhibitors

Abstract

Ribosome biogenesis involves the processing of precursor ribosomal RNAs (pre-rRNAs) and sequential assembly with ribosomal proteins. Here we report that nutrient deprivation severely impairs pre-rRNA processing and leads to the accumulation of unprocessed rRNAs. Upon nutrient restoration, the accumulated pre-rRNAs are processed into mature rRNAs that are utilized for ribosome biogenesis. Failure to accumulate pre-rRNAs under nutrient deprivation leads to perturbed ribosome assembly during nutrient restoration and subsequent apoptosis via uL5/uL18-mediated activation of p53. Restoration of glutamine alone activates p53 by triggering uL5/uL18 translation. Induction of uL5/uL18 protein synthesis by glutamine was dependent on the translation factor eukaryotic elongation factor 2 (eEF2), which was in turn dependent on Raf/MEK/ERK signalling. Depriving cells of glutamine prevents the activation of p53 by rRNA synthesis inhibitors. Our data reveals a mechanism that cancer cells can exploit to suppress p53-mediated apoptosis during fluctuations in environmental nutrient availability.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Pan, M., Zorbas, C., Sugaya, M., Ishiguro, K., Kato, M., Nishida, M., Zhang, H., Candeias, M. M., Okamoto, A., Ishikawa, T., Soga, T., Aburatani, H., Sakai, J., Matsumura, Y., Suzuki, T., Proud, C. G., Lafontaine, D. L. G., Osawa, T.. 2021-12-04. Glutamine deficiency in solid tumors confers resistance to ribosomal RNA synthesis inhibitors. https://doi.org/10.1101/2021.12.03.471189

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

EWSR1::ATF1 hyperactivation via TRIM11 depletion triggers lethal metabolic rewiring in clear cell sarcoma

Clear cell sarcoma (CCS) is an ultra-rare and aggressive soft tissue sarcoma driven by the EWSR1::ATF1 fusion oncoprotein. Currently, no effective and well-tolerated treatment options are available to CCS patients. Direct inhibition of fusion transcription factors is precluded by the absence of defined ligand-binding pockets, whereas their abundance is under the control of the ubiquitin-proteasome system (UPS), offering an alternative avenue for biology-guided treatment. Here we show the abundance of EWSR1::ATF1 is tightly regulated by the UPS, and that release of this constraint is lethal to CCS cells. A reporter-based CRISPR/Cas9 knockout screen of UPS components identified TRIM11 as an E3 ligase that regulates turnover of EWSR1::ATF1, which it recognises as a neosubstrate without altering wild-type EWSR1 or ATF1. Depletion of TRIM11 increased nuclear fusion protein abundance, amplified the fusion-driven transcriptional programs and reduced viability. Proteomic analysis identified the cataplerotic enzyme phosphoenolpyruvate carboxykinase 1 (PCK1), a direct EWSR1::ATF1 target, as the key mediator of lethal effects of fusion hyperactivation. Extracellular flux analysis, isotope tracing and quantitative metabolomics revealed excessive cataplerotic carbon withdrawal and impaired oxidative phosphorylation as the underlying mechanism. In patient tumors, high PCK1 expression associated with metastatic transcriptome programs and disease presentation, as well as shorter survival. Taken together, we report that hyperactivation of EWSR1::ATF1 opens a metabolic vulnerability, establishing TRIM11 as an actionable dependency and PCK1 as a candidate prognostic biomarker in CCS.

cancer biology↗

Glycolysis and interferon transcription in melanoma immunotherapy

Glycolysis and interferon signalling have both been associated with responses to PD-1 blockade, but their joint transcriptional relationship with treatment outcome remains uncertain. We examined whether a state with high glycolysis and low interferon- response was associated with reduced disease control in melanoma. Fixed Hallmark gene sets were scored by single-sample gene set enrichment analysis in GSE91061, GSE78220 and an additional Liu cohort. Disease control analyses included 47, 26 and 100 patients. Conditional odds ratios for the joint state were 6.06 (exact 95% confidence interval, 1.04 to 65.61), 0.35 (0.026 to 3.11) and 1.03 (0.39 to 2.73), respectively. Holm-adjusted P values for the two initial comparisons were 0.073 and 0.365. The additional exploratory P value was 1.000. Continuous models and analyses that omitted each patient in turn did not provide consistent evidence of an adverse association. IFN scores were negatively correlated with DNA-derived tumour purity in 102 patients (Spearman {rho} = -0.671). Among 40 patients with paired biopsies, disease control was associated with higher on-treatment IFN scores after baseline adjustment, although the paired subset had lower baseline glycolysis than patients without paired profiles. In patient-level single-cell analyses, the baseline CD8 T cell correlation weakened when an alternative rank score used a common gene background. The defined joint state was not consistently associated with poorer disease control across cohorts. Bulk IFN scores were related to tumour purity, and cellular correlations were sensitive to scoring choices. These transcriptomic results do not measure pyruvate concentration, glycolytic flux or STAT1 pyruvylation.

cancer biology↗

Psychoneuroimmunology of Viral Hepatitis and Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Hepatocellular carcinoma (HCC) and viral hepatitis (VH) are recognized primarily as hepatic diseases, yet they impose a substantial neuropsychiatric disorders (NPDs) encompassing depression, anxiety, cognitive impairment, and fatigue. Whether these manifestations reflect psychological reactions or biologically grounded psychoneuroimmune dysfunction remains poorly understood. Here, we present a pre-registered systematic review and meta-analysis (PROSPERO 2026 CRD420251081757) synthesizing evidence from 24 studies combining psychosocial outcomes with immune dysregulation markers across HCC and VH populations. Bibliometric and network analyses identified a growing psychoneuroimmunology research hub linking cytokine signaling, microglial activation, blood-brain barrier (BBB) disruption, and gut-liver-brain axis dysregulation to the neuropsychiatric phenotype of these diseases. Meta-analysis revealed a pooled hazard ratio (HR) of 1.92 (95% CI: 1.09-3.39) for adverse outcomes in HCC and a pooled HR of 2.28 (95% CI: 1.48-3.52) for depression associated to genetic variants in VH. TNF-a, but not IL-6, showed a tendency toward lower levels in VH patients with versus without NPDs, suggesting differential inflammatory roles. The literature, however, remains fragmented by heterogeneous designs and a paucity of longitudinal data. A psychoneuroimmunological approach, integrating immune, endocrine, neural, and psychosocial dimensions, is essential for capturing the full systemic impact of HCC and VH and should inform future mechanistic research and multidisciplinary clinical strategies.

cancer biology↗