Multi-omic profiling reveals an RNA processing rheostat that predisposes to prostate cancer

Extracellular Microvesicle MicroRNAs and Imaging Metrics Improve the Detection of Aggressive Prostate Cancer: A Pilot Study

Background/Objectives: Prostate cancer (PCa) is the most diagnosed cancer in men worldwide. Early diagnosis of the disease provides better treatment options for these patients. Recent studies have demonstrated that plasma-based extracellular vesicle microRNAs (miRNAs) are functionally linked to cancer progression, metastasis, and aggressiveness. The use of magnetic resonance imaging (MRI) as the standard of care provides an overall assessment of prostate disease. Quantitative metrics (radiomics) from the MRI provide a better evaluation of the tumor and have been shown to improve disease detection. Methods: We conducted a study on prostate cancer patients, analyzing baseline blood plasma and MRI data. Exosomes were isolated from blood plasma samples to quantify miRNAs, while MRI scans provided detailed tumor morphology. Radiomics features from MRI and miRNA expression data were integrated to develop predictive models, which were evaluated using ROC curve analysis, highlighting the multivariable model's effectiveness. Results: Our findings indicate that the univariate feature-based model with the highest Youden's index achieved average areas under the receiver operating characteristic (ROC) curve of 0.76, 0.82, and 0.84 for miRNA, MR-T2W, and MR-ADC features, respectively, in identifying clinically aggressive (Gleason grade) disease. The multivariable feature-based model yielded an average area under the curve (AUC) of 0.88 and 0.95 using combinations of miRNA markers with imaging features in MR-ADC and MR-T2W, respectively. Conclusions: Our study demonstrates that combining miRNA markers with MRI-based radiomics improves the identification of clinically aggressive prostate cancer.

Pan-cancer and multiomics: advanced strategies for diagnosis, prognosis, and therapy in the complex genetic and molecular universe of cancer

The pan-cancer and multi-omics approach is motivated by the genetic and molecular complexity inherent in the varied types of cancer. This method presents itself as a crucial resource for advancing early diagnosis, defining prognoses and identifying treatments that share common bases between different forms of tumors. The aim of this article is to explore pan-cancer analysis in conjunction with multi-omics strategies, evaluating laboratory, computational, clinical procedures and their consequences, as well as examining the tumor microenvironment, epigenetics and future directions of these technologies in patient management. To this end, a literature review was conducted using PUBMED, resulting in the selection of 260 articles, of which 81 were carefully chosen to support this analysis. The pan-cancer methodology is applied to the study of this microenvironment with the aim of investigating its common characteristics through multiomics data. The development of new therapies depends on understanding the oncogenic pathways associated with different cancers. Thus, the integration of multi-omics and pan-cancer analyzes offers an innovative perspective in the search for new control points, metabolic pathways and markers, in addition to facilitating the identification of patterns common to multiple cancer types, allowing the development of targeted treatments. In this way, the convergence of multiomics and clinical approaches promotes a broad view of cancer biology, leading to more effective and personalized therapies.

Structural insights into human ELAC2 as a tRNA 3' processing enzyme

Human elaC ribonuclease Z 2 (ELAC2) removes the 3' trailer of precursor transfer ribonucleic acid (pre-tRNA). Mutations in ELAC2 are highly associated with the development of prostate cancer and hypertrophic cardiomyopathy. However, the catalytic mechanism of ELAC2 remains unclear. We determined the cryogenic electron microscopy structures of human ELAC2 in various states, including the apo, pre-tRNA-bound and tRNA-bound states, which enabled us to identify the structural basis for its binding to pre-tRNA and cleavage of the 3' trailer. Notably, conformational rearrangement of the C-terminal helix was related to feeding of the 3' trailer into the cleavage site, possibly explaining why its mutations are associated with disease. We further used biochemical assays to analyse the structural effects of disease-related mutations of human ELAC2. Collectively, our data provide a comprehensive structural basis for how ELAC2 recruits pre-tRNA via its flexible arm domain and guides the 3' trailer of pre-tRNA into the active centre for cleavage by its C-terminal helix.

Illuminating mitochondrial translation through mouse models

Mitochondria are hubs of metabolic activity with a major role in ATP conversion by oxidative phosphorylation (OXPHOS). The mammalian mitochondrial genome encodes 11 mRNAs encoding 13 OXPHOS proteins along with 2 rRNAs and 22 tRNAs, that facilitate their translation on mitoribosomes. Maintaining the internal production of core OXPHOS subunits requires modulation of the mitochondrial capacity to match the cellular requirements and correct insertion of particularly hydrophobic proteins into the inner mitochondrial membrane. The mitochondrial translation system is essential for energy production and defects result in severe, phenotypically diverse diseases, including mitochondrial diseases that typically affect postmitotic tissues with high metabolic demands. Understanding the complex mechanisms that underlie the pathologies of diseases involving impaired mitochondrial translation is key to tailoring specific treatments and effectively targeting the affected organs. Disease mutations have provided a fundamental, yet limited, understanding of mitochondrial protein synthesis, since effective modification of the mitochondrial genome has proven challenging. However, advances in next generation sequencing, cryoelectron microscopy, and multi-omic technologies have revealed unexpected and unusual features of the mitochondrial protein synthesis machinery in the last decade. Genome editing tools have generated unique models that have accelerated our mechanistic understanding of mitochondrial translation and its physiological importance. Here we review the most recent mouse models of disease pathogenesis caused by defects in mitochondrial protein synthesis and discuss their value for preclinical research and therapeutic development.

Germline status and micronutrient availability regulate a somatic mitochondrial quality control pathway via short-chain fatty acid metabolism

Reproductive status, such as pregnancy and menopause in women, profoundly influences metabolism of the body. Mitochondria likely orchestrate many of these metabolic changes. However, the influence of reproductive status on somatic mitochondria and the underlying mechanisms remain largely unexplored. We demonstrate that reproductive signals modulate mitochondria in the Caenorhabditis elegans soma. We show that the germline acts via an RNA endonuclease, HOE-1, which despite its housekeeping role in tRNA maturation, selectively regulates the mitochondrial unfolded protein response (UPRmt). Mechanistically, we uncover a fatty acid metabolism pathway acting upstream of HOE-1 to convey germline status. Furthermore, we link vitamin B12's dietary intake to the germline's regulatory impact on HOE-1-driven UPRmt. Combined, our study uncovers a germline-somatic mitochondrial connection, reveals the underlying mechanism, and highlights the importance of micronutrients in modulating this connection. Our findings provide insights into the interplay between reproductive biology and metabolic regulation.

A POLR3B-variant reveals a Pol III transcriptome response dependent on La protein/SSB

RNA polymerase III (Pol III, POLR3) synthesizes tRNAs and other small non-coding RNAs. Human POLR3 pathogenic variants cause a range of developmental disorders, recapitulated in part by mouse models, yet some aspects of POLR3 deficiency have not been explored. We characterized a human POLR3B:c.1625A>G;p.(Asn542Ser) disease variant that was found to cause mis-splicing of POLR3B. Genome-edited POLR3B1625A>G HEK293 cells acquired the mis-splicing with decreases in multiple POLR3 subunits and TFIIIB, although display auto-upregulation of the Pol III termination-reinitiation subunit POLR3E. La protein was increased relative to its abundant pre-tRNA ligands which bind via their U(n)U-3'-termini. Assays for cellular transcription revealed greater deficiencies for tRNA genes bearing terminators comprised of 4Ts than of ≥5Ts. La-knockdown decreased Pol III ncRNA expression unlinked to RNA stability. Consistent with these effects, small-RNAseq showed that POLR3B1625A>G and patient fibroblasts express more tRNA fragments (tRFs) derived from pre-tRNA 3'-trailers (tRF-1) than from mature-tRFs, and higher levels of multiple miRNAs, relative to control cells. The data indicate that decreased levels of Pol III transcripts can lead to functional excess of La protein which reshapes small ncRNA profiles revealing new depth in the Pol III system. Finally, patient cell RNA analysis uncovered a strategy for tRF-1/tRF-3 as POLR3-deficiency biomarkers.

ELAC2 is a functional prostate cancer risk allele

Stentenbach and colleagues have unveiled a functional role of a human germline mutation found in the ribonuclease (RNase) Z enzyme, ELAC2, in prostate cancer. Here, we discuss the importance of these findings in enhancing our understanding of how risk variants enable prostate cancer progression and the post-transcriptional mechanisms underlying oncogenesis.