TRMT112 Drives A Tumor Growth and Metastasis-Promoting Program in Triple-Negative Breast Cancer

Ribosomal RNA Modifying Proteins (RRMPs) are integral to ribosome biogenesis, executing post-transcriptional modifications that influence translation fidelity and efficiency. Dysregulation of RRMPs has been increasingly implicated in cancer progression, yet their collective role across malignancies remains largely unexplored. Here, we performed a multi-omics analysis of 22 RRMPs across diverse cancer types using The Cancer Genome Atlas, the Molecular Taxonomy of Breast Cancer International Consortium, and additional high-throughput datasets. Our analysis revealed widespread genomic alterations and transcriptional dysregulation of RRMPs across malignancies, with distinct expression patterns in breast cancer subtypes. Notably, Triple-Negative Breast Cancer (TNBC) exhibited the highest RRMPs enrichment, which correlated with increased genomic instability including elevated tumor mutational burden and aneuploidy scores, and poor survival outcomes. Among the RRMPs, tRNA methyltransferase activator subunit 11-2 (TRMT112) emerged as a key regulator of tumor progression. Functional assays demonstrated that TRMT112 knockdown in TNBC cells significantly reduced proliferation, migration, invasion, and metastatic potential, whereas its overexpression enhanced these tumorigenic properties. Polysome profiling and RNA sequencing of actively translated transcripts revealed that TRMT112 reprograms the translational landscape by promoting pro-metastatic and stromal remodeling pathways while suppressing immune-related processes. In vivo studies using an orthotopic breast cancer model further confirmed that TRMT112 depletion impairs tumor growth and reduces metastatic burden. Collectively, our findings establish RRMPs as critical modulators of cancer progression and identify TRMT112 as a key driver of aggressive phenotypes in TNBC. The dysregulation of TRMT112 across breast cancer subtypes highlights its potential as both a prognostic biomarker and a therapeutic target. These insights provide a mechanistic foundation for future interventions aimed at targeting TRMT112-driven translational programs in aggressive breast cancer. Overall design: To investigate how silencing or overexpressing TRMT112 affects transcript translation and associated protein networks, we performed polysome profiling in the breast cancer cell lines MDA-MB-231, SUM159, and BT-549. Polysomes were isolated from these cells using a sucrose gradient fractionation system. RNA-seq was subsequently performed on the polysome fractions to identify transcripts actively translated by ribosomes under TRMT112 knockdown and overexpression conditions. This approach allowed us to assess how TRMT112 modulates translational activity and impacts gene expression at the level of protein synthesis.