Biology subjects

Federico, C.

Publications and source records attributed to Federico, C..

4 recordsLinked to original sources

bioRxiv2026

The KRAS G12C Inhibitor Divarasib Stabilizes RBM39 and Antagonizes Aryl-Sulfonamide Degraders

KRAS G12C inhibitors have demonstrated meaningful clinical benefit in KRAS G12C-mutant non-small cell lung cancer (NSCLC), yet responses remain heterogeneous and treatment-associated toxicities persist for reasons that are incompletely understood. Cysteine profiling indicates that these covalent inhibitors are highly selective for mutant KRAS; however, such approaches cannot detect noncovalent engagement of additional non-RAS proteins. Here, we used a protein-folding stability profiling technique, stability of proteins from rates of oxidation (SPROX), to identify protein targets of the clinical KRAS G12C inhibitor, divarasib (GDC-6036), in KRAS-mutant NSCLC lysates. SPROX revealed a focused set of candidate interactors, including the essential splicing factor RBM39, which was reproducibly stabilized at both divarasib concentrations tested. We subsequently confirmed that divarasib directly and noncovalently binds to RBM39 protein. In NSCLC cells, divarasib increased RBM39 protein abundance and antagonized RBM39 degradation induced by the aryl-sulfonamide molecular glue indisulam through a post-transcriptional mechanism. Divarasib and RBM39 degraders reciprocally antagonized each other's cytotoxicity, and RBM39 knockdown modestly reduced divarasib-induced cell death. Mechanistically, divarasib-mediated RBM39 stabilization regulated both INSR expression and alternative splicing, altered downstream insulin receptor signaling, and contributed to divarasib-associated cytotoxicity. Consistent with these findings, RBM39 and INSR expression were positively correlated across multiple human cancer types. Collectively, these findings identify RBM39 as a previously unrecognized noncovalent target of divarasib and uncover an RBM39-INSR signaling axis that modulates cellular responses to both divarasib and RBM39 degraders.

pharmacology and toxicology↗

bioRxiv2024

Ascitic fluid protects against ferroptosis and enables the peritoneal spread of ovarian cancer

One of the most common sites of metastasis in ovarian cancer (OVCA) is the peritoneum. Often, this spread is accompanied by the accumulation of a fluid called ascites in the peritoneal cavity. Despite its common occurrence in metastatic OVCA patients, ascites and its influence on the peritoneal spread of OVCA are poorly understood. Interestingly, OVCA cells are vulnerable to ferroptosis, a type of cell death caused by lipid peroxidation. Hence, how these ferroptosis-sensitive OVCA cells persist in their spread to the peritoneum remains unknown. Here, we show that ascites robustly protects OVCA cells and patient-derived organoids against ferroptosis and enhances the peritoneal spread of OVCA cells in mice. Mechanistically, ascites downregulates the mitochondrial enzyme, 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), which contributes to an increase in lipid droplets. Additionally, upon ferroptosis induction, ascites represses the upregulation of the transferrin receptor, TFRC, thereby decreasing cellular labile iron levels. Furthermore, we show that lipid-lowering fibrates reverse cellular changes induced by ascites, and they attenuate the peritoneal spread of OVCA cells in mice. Our findings implicate the importance of ascites in ferroptosis protection and the peritoneal spread of OVCA, and they suggest that targeting the ferroptosis protection by ascites may present a novel therapeutic approach to limit OVCA metastasis.

cancer biology↗

bioRxiv2022

Engineered model of t(7;12)(q36;p13) AML recapitulates patient-specific features and gene expression profiles

Acute myeloid leukaemia carrying the translocation t(7;12)(q36;p13) is an adverse-risk leukaemia uniquely observed in infants. Despite constituting up to 30% of cases in under 2-year-olds, it remains poorly understood. Known molecular features are ectopic overexpression of the MNX1 gene and generation of a fusion transcript in 50% of patients. Lack of research models has hindered understanding of t(7;12) biology, which has historically focused on MNX1 overexpression rather than the cytogenetic entity itself. Here, we employed CRISPR/Cas9 to generate t(7;12) in the human K562 cell line, and in healthy CD34+ haematopoietic progenitors where the translocation was not sustained in long-term cultures or through serial replating. In contrast, in K562 cells, t(7;12) was propagated in self-renewing clonogenic assays, with sustained myeloid bias in colony formation and baseline depletion of erythroid signatures. Nuclear localisation analysis revealed repositioning of the translocated MNX1 locus to the interior of t(7;12)-harbouring K562 nuclei - a known phenomenon in t(7;12) patients which associates with ectopic overexpression of MNX1. Crucially, the K562-t(7;12) model successfully recapitulated the transcriptional landscape of t(7;12) patient leukaemia. In summary, we engineered a clinically-relevant model of t(7;12) acute myeloid leukaemia with the potential to unravel targetable molecular mechanisms of disease.

cancer biology↗

bioRxiv2021

Long Noncoding RNA RROL Provides Chromatin Scaffold for MYC-WDR82 Interaction to Impact Lipid Metabolism and Tumor Cell Growth in Multiple Myeloma

Long noncoding RNAs (lncRNA) can drive the tumorigenesis and be susceptible to therapeutic intervention. To define the landscape of therapeutically actionable lncRNA dependencies in multiple myeloma (MM), we coupled our extensive lncRNA transcriptomic profile with lncRNA targeted CRISPR interference viability screen and identified RNA Regulator of Lipogenesis (RROL) as a leading lncRNA dependency in MM. RROL shares its origin with the microRNA locus MIR17HG, however supports the proliferation and survival of MM cells in a microRNA- and DROSHA- independent manner. We found that RROL provides a chromatin scaffold for the functional interaction between c-MYC and WDR82 to promote the regulation of the lipogenic pathways via the transcriptional control of the rate-limiting enzyme ACC1 in MM cells. Inhibition of RROL with clinically applicable antisense molecules disrupts its transcriptional and functional activities causing potent anti-tumor effects both in vitro and in vivo in two pre-clinical animal models. This study establishes lncRNA RROL as a therapeutically actionable dependency with a unique mechanism of action in support of myeloma cell growth.

cancer biology↗