Biology subjects

Aguilo, F.

Publications and source records attributed to Aguilo, F..

7 recordsLinked to original sources

bioRxiv2025

METTL3-mediated m6A modification of DNMT1 enhances ovarian cancer progression

High-grade serous carcinoma (HGSC), the most lethal subtype of ovarian cancer, is often diagnosed at advanced stages owing to its asymptomatic progression and lack of early detection markers. In this study, we identified a critical oncogenic role of the RNA methyltransferase METTL3 and the N6-methyladenosine (m6A) RNA modification pathway in HGSC. Depletion of METTL3 or its binding partner METTL14 impairs ovarian cancer proliferation and tumor progression. Mechanistically, m6A deposition enhances the translation of DNA methyltransferase DNMT1, an epigenetic repressor that silences tumor suppressor genes. Pharmacologic inhibition of DNMT1 led to DNA hypomethylation and upregulation of the tumor suppressors TNFAIP3 and FBXO32. Consistently, METTL3 depletion also increased the expression of these genes supporting a model in which METTL3 sustains oncogenesis by maintaining DNMT1 protein levels and repressing anti-tumor pathways. These findings position METTL3-mediated RNA modifications and DNMT1 as promising therapeutic targets in HGSC.

cancer biology↗

bioRxiv2025

METTL3 regulates exocytosis independently of m6A

RNA modification pathways are often mis-regulated in various cancers, with N6-methyladenosine (m6A) having a pivotal role in cancer progression and metastasis. Methyltransferase-like 3 (METTL3), a core component of the m6A methyltransferase complex, functions not only as an m6A writer but also promotes tumorigenesis through m6A-independent mechanisms. Here, we show that METTL3 is mislocalized to the cytoplasm in breast cancer tumors from patients, contributing to the oncogenic phenotype. Cytoplasmic METTL3 interacts with EXOC7, a key regulator of exocytosis, promoting its stabilization. Additionally, METTL3 regulates m6A-dependent alternative splicing of EXOC7. Silencing METTL3 impairs vesicle trafficking and the breast cancer secretome - effects that do not rely on its enzymatic activity but instead involve METTL3-mediated stabilization of EXOC7 and potentially other exocyst components. Furthermore, METTL3 knockdown impairs invadopodia formation, collagen matrix invasion, and focal adhesion morphology in vitro, while inhibition of METTL3 catalytic activity does not. Our findings uncover non-catalytic roles of METTL3 in regulating exocytosis and the cancer secretome.

molecular biology↗

bioRxiv2025

Fibrillarin shapes oncogenic protein pools and ribosomal composition in triple-negative breast cancer

Fibrillarin (FBL), a core component of the C/D box snoRNP complex, catalyzes 2-O-methylation (Nm) of ribosomal RNA (rRNA), influencing ribosome heterogeneity and oncogene translation. In triple-negative breast cancer (TNBC), FBL dysregulation creates an aberrant Nm signature. This study explores role of FBL in TNBC progression via translation-driven mechanisms. FBL knockdown impaired tumorigenic traits, induced metabolic stress, and reduced the translation efficiency of oncogenes, including metastasis-associated protein 1 (MTA1), interleukin-1 receptor-associated kinase 1 (IRAK1), and thymosin beta 10 (TMSB10). RiboMethSeq analysis revealed differential rRNA Nm site sensitivity to FBL depletion. Additionally, FBL knockdown lowered RPS28 protein levels, suggesting its misincorporation into ribosomes. Notably, silencing RPS28 also suppressed oncogenic traits and downregulated MTA1, IRAK1, and TMSB10, highlighting its role in FBL-mediated translation. These findings uncover a complex interplay between FBL, rRNA Nm modifications, and RPS28 in shaping oncogenic protein pools and ribosomal composition in TNBC. Targeting this pathway could offer novel therapeutic strategies for this aggressive cancer subtype.

molecular biology↗

bioRxiv2023

coRIC map: a framework for the exploration of multifaceted subcellular RNA-binding proteins

The ability of RNA-binding proteins (RBPs) to form complexes with other biomolecules underpins a broad range of functions and remarkable structural properties. Understanding the precise spatiotemporal dynamics of RBPs and their interacting partners in the steady state and upon perturbation is key to deciphering these aspects. Here, we present the coRIC (compartmentalized RNA Interactome Capture) map, an experimental resource and analytical pipeline to study the subcellular dynamics of RBPs through multimodal dataset integration and machine learning. Using this approach, we have generated an atlas comprising 1,768 RBPs distributed in a broad panel of subcellular compartments and delineated their intermolecular and intercompartmental relationships. We have also defined the hierarchy of RBP-containing complexes at multiple scales across the cell, uncovering previously unknown functions of multiple RBPs. Furthermore, we have investigated the changes in RBP complex composition and subcellular distribution in response to C9ORF72 amyotrophic lateral sclerosis/frontotemporal dementia dipeptide repeats and DNA damage stress. The coRIC map provides a valuable new approach for defining the roles of RBPs in homeostasis and disease.

cell biology↗

bioRxiv2023

The catalytic-independent function of LSD1 modulates the epigenetic landscape of mouse embryonic stem cells

Lysine-specific histone demethylase 1 (LSD1), which demethylates mono- or di-methylated histone H3 on lysine 4 (H3K4me1/2), is essential for early embryogenesis and development. Here we show that LSD1 is dispensable for embryonic stem cell (ESC) self-renewal but is required for ESC growth and differentiation. Reexpression of a catalytically-dead LSD1 (LSD1MUT) recovers the proliferation capability of ESCs, yet the enzymatic activity of LSD1 is essential to ensure proper differentiation. Indeed, a gain of H3K4me1 in Lsd1 knockout (KO) ESCs does not lead to major changes in global gene expression programs related to stemness. However, ablation of LSD1 but not LSD1MUT results in decreased DNMT1 and UHRF1 proteins coupled to global hypomethylation. We show that both LSD1 and LSD1MUT control protein stability of UHRF1 and DNMT1 through interaction with the ubiquitin-specific peptidase 7 (USP7) and, consequently, inhibiting DNMT1 and UHRF1 ubiquitylation. Our studies elucidate for the first time a novel mechanism by which the scaffolding function of LSD1 controls DNA methylation in ESCs.

molecular biology↗

bioRxiv2022

METTL3 regulates breast cancer-associated alternative splicing switches

Alternative splicing (AS) enables differential inclusion of exons from a given transcript, thereby contributing to the transcriptome and proteome diversity. Aberrant AS patterns play major roles in the development of different pathologies, including breast cancer. N6-methyladenosine (m6A), the most abundant internal modification of eukaryotic mRNA, influences tumor progression and metastasis of breast cancer, and it has been recently linked to AS regulation. Here, we identify a specific AS signature associated with breast tumorigenesis in vitro. We characterize for the first time the role of METTL3 in modulating breast cancer-associated AS programs, expanding the role of the m6A-methyltransferase in tumorigenesis. Specifically, we find that both m6A deposition in splice site boundaries and in splicing and transcription factor transcripts, such as PHF5A and MYC, direct AS switches of specific breast cancer-associated transcripts. Finally, we show that five of the AS events validated in vitro are associated with a poor overall survival rate for patients with breast cancer, suggesting the use of these AS events as a novel potential prognostic biomarker.

cell biology↗

bioRxiv2021

ZFP207 controls pluripotency by multiple post-transcriptional mechanisms

The pluripotent state is not solely governed by the action of the core transcription factors Oct4, Sox2, and Nanog, but also by a series of co-transcriptional and post-transcriptional events, including alternative splicing (AS) and the interaction of RNA-binding proteins (RBPs) with defined subpopulations of RNAs. Zinc Finger Protein 207 (ZFP207) is an essential transcription factor for mammalian embryonic development. Here, we employ multiple functional analyses to characterize the role of ZFP207 in mouse embryonic stem cells (ESCs). We find that ZFP207 plays a pivotal role in ESC maintenance, and silencing of Zfp207 leads to severe neuroectodermal differentiation defects. In striking contrast to human ESCs, ZFP207 does not transcriptionally regulate stem cell and neuronal-related genes but exerts its effects by control AS networks and acting as an RBP. Our study expands the role of ZFP207 to maintain ESC identity, and underscores ZFP207 functional versatility with key roles in neural fate commitment.

cell biology↗