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SALGADO, G.

Publications and source records attributed to SALGADO, G..

2 recordsLinked to original sources

Self-Assembled Nucleolipid G-Quadruplexes Act as Multitarget Decoys for Oncogene Suppression in Pancreatic Cancer

KRAS mutations drive multiple cancers and represent an important therapeutic target, together with other oncogenic regulators such as MYC, KIT, and BCL2 that are critically involved in pancreatic cancer. Here we describe a novel therapeutic strategy based on stable nucleolipid-modified G-quadruplexes (NLG4). Cell viability assays demonstrate that NLG4 strongly inhibit pancreatic cancer cell proliferation, whereas non-lipidic G-quadruplex sequences display minimal activity under comparable conditions. Owing to their distinctive physicochemical properties, including stabilization of parallel G-quadruplex structures and self-assembly into micellar aggregates, NLG4 efficiently internalize into cells and interact with key G-quadruplex unfolding factors such as UP1. This interaction leads to a marked downregulation of KRAS, c-MYC, c-KIT, and BCL2 expression. Suppression of these oncogenes profoundly affects pancreatic cancer cell fate, as evidenced by reduced expression of proliferation (Ki67) and anti-apoptotic (BCL2) markers. In addition, NLG4 treatment decreases inflammatory signaling mediated by NF-{kappa}B and inhibits major pro-proliferative kinase pathways, including ERK, AKT, and phosphorylated AKT. The therapeutic relevance of this decoy strategy is further supported by the observed potentiation of gemcitabine antitumor activity. Overall, these findings highlight NLG4 as a promising anticancer approach that simultaneously targets multiple oncogenic pathways through G-quadruplex-based decoy mechanisms, with translational potential for future pancreatic cancer treatment.

biochemistry↗

Recognition and Resolution of KRAS 5'UTR RNA G-Quadruplexes by hnRNPA1

The KRAS oncogene, central to cellular signaling via MAPK and PI3K-AKT pathways, is a notorious cancer driver frequently activated in pancreatic, colorectal, and lung carcinomas. Regulation of human KRAS oncogene expression is important due to its capital role in cell growth, proliferation, and survival. Misregulation of its expression contributes directly to the development and progression of multiple types of cancer. In previous studies, the role of G-quadruplexes elements in both the promoter and 5 UTR regions have shown to play important roles in KRAS expression, particularly when these G4s elements interact with regulatory protein hnRNPA1. In this study, we reveal that KRAS expression is also modulated at the post-transcriptional level through the formation of RNA G-quadruplexes (rG4s) situated at the 5 untranslated region (5UTR) of the mRNA. Biophysical and binding studies were carried out to probe the interaction. Through isothermal titration calorimetry (ITC), we quantified a strong binding affinity between the UP1 domain of hnRNPA1 and short-nucleotide RNA segments capable of adopting different G-quadruplex fold. The binding interaction is characterized by a favorable Gibbs free energy change in the range of {Delta}G {approx} -32 to -34 kJ/mol, suggesting a specific and energetically favorable association. One-dimensional and two-dimensional 1H-15N HSQC NMR spectroscopy revealed pronounced chemical shift changes in residues of both RNA recognition motifs (RRMs) of UP1, signifying direct contact with the rG4 structure.

biophysics↗