Biology subjects

Rocco, S. A.

Publications and source records attributed to Rocco, S. A..

3 recordsLinked to original sources

bioRxiv2023

Iron Oxide Nanoparticles Coated with Biodegradable Block-Copolymer PDMAEMA-b-PMPC and Functionalized with Aptamer for HER2 Breast Cancer Cell Identification

Hybrid nanoparticles have shown promise in biomedical applications; however, their seamless integration into clinical settings remains challenging. Here, we introduce a novel metal oxide polymer hybrid nanoparticle (NP) with a high affinity for nucleic acids. Iron oxide nanoparticles (IONP) were initially synthesized via the co-precipitation method and subjected to comprehensive characterization. Subsequently, block copolymers were synthesized using the Reversible Addition-Fragmentation Chain Transfer (RAFT) technique, employing the zwitterionic PMPC (Poly (2 Methacryloyloxyethyl Phosphorylcholine)) and the cationic PDMAEMA (Poly(2 (Dimethylamino) Ethyl Methacrylate)) with varying degrees of polymerization. In vitro cytotoxicity studies demonstrated the biocompatibility of the synthesized nanoparticles, with no observed toxicity up to a concentration of 150 {micro}g/mL. The cationic polymer PDMAEMA facilitated the facile coating of IONP, forming the IONPP complex, consisting of a 13.27 metal core and a 3.1 nm block-copolymer coating. Subsequently, the IONPP complex was functionalized with a DNA aptamer specifically targeting the human epidermal growth factor receptor 2 (HER2) in breast cancer, forming IONPPP. The block-copolymer exhibited an EC50 of 7.07 {micro}g/mL and demonstrated enhanced recognition efficiency in HER2-amplified SKBR3 cells. Our study presents a comprehensive IONPPP characterization capable of binding short DNA sequences and targeting proteins such as HER2. This newly developed nanoparticle holds significant potential for cancer cell identification and isolation, offering promising prospects in cancer research and clinical applications. 1. Statement of significanceDespite recent advancements in biomedical research, developing sensitive and specific tools for recognizing biological motifs, such as cell receptors and proteins in complex biological solutions, remains a challenge. Furthermore, current approaches often rely on complex biological derivatives like antibodies, lacking a cost-effective delivery strategy. Our study proposes creating and characterizing a novel hybrid metal oxide polymer nanoparticle named IONPPP, functionalized with a DNA aptamer designed to recognize HER2-positive cells. HER2 is a clinically actionable marker for gastric, gastroesophageal, and, particularly, breast cancers. This unique combination of a metal core with an external polymeric structure offers the potential for identification, isolation, and even theragnostic applications, benefiting from its low toxicity and high specificity. 2. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/543859v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@ff36a9org.highwire.dtl.DTLVardef@15da74corg.highwire.dtl.DTLVardef@1929c6aorg.highwire.dtl.DTLVardef@5afd2f_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2020

Using a fragment-based approach to identify novel chemical scaffolds targeting the dihydrofolate reductase (DHFR) from Mycobacterium tuberculosis

Dihydrofolate reductase (DHFR), a key enzyme involved in folate metabolism, is a widely explored target in the treatment of cancer, immune diseases, bacteria and protozoa infections. Although several antifolates have proved successful in the treatment of infectious diseases, none have been developed to combat tuberculosis, despite the essentiality of M. tuberculosis DHFR (MtDHFR). Herein, we describe an integrated fragment-based drug discovery approach to target MtDHFR that has identified hits with scaffolds not yet explored in any previous drug design campaign for this enzyme. The application of a SAR by catalog strategy of an in house library for one of the identified fragments has led to a series of molecules that bind MtDHFR with low micromolar affinities. Crystal structures of MtDHFR in complex with compounds of this series demonstrated a novel binding mode that differs from other DHFR antifolates, thus opening perspectives for the development of novel and relevant MtDHFR inhibitors.

biochemistry↗

bioRxiv2017

Cadmium exposure inhibits branching morphogenesis and causes alterations consistent with HIF-1α inhibition in human primary breast organoids

BackgroundDevelopmental cadmium exposure in vivo disrupts mammary gland differentiation, while exposure of breast cell lines to cadmium causes invasion consistent with the epithelial-mesenchymal transition (EMT). The effects of cadmium on normal human breast stem cell development have not been measured.\n\nObjectiveThe objective of this study was to quantify the effects of cadmium exposure on normal breast stem cell proliferation and differentiation.\n\nMethodsWe tested the effects of two physiologically relevant doses of cadmium: 250M and 2.5M on reduction mammoplasty patient-derived breast cells using the mammosphere assay, organoid formation in 3D hydrogels, and tested for molecular alterations using RNA-seq. We functionally validated our RNA-seq findings with a HIF-1 transcription factor activity reporter line and pharmaceutical inhibition of HIF-1 in mammosphere and organoid formation assays.\n\nResults2.5M cadmium reduced primary and secondary mammosphere formation and branching structure organoid formation rates by 33%, 40%, and 83%, respectively. Despite no changes in mammosphere formation, 0.25M cadmium treatment inhibited branching organoid formation in hydrogels by 68%. RNA-seq revealed that cadmium treatment downregulated genes associated with extracellular matrix formation and EMT, while upregulating genes associated with metal response including metallothioneins and zinc transporters. In the RNA-seq data, cadmium treatment also downregulated HIF-1 target genes including LOXL2, ZEB1, and VIM. Cadmium treatment significantly inhibited HIF-1 activity in a luciferase assay, and the HIF-1 inhibitor acriflavine ablated mammosphere and organoid formation.\n\nDiscussionThese findings show that cadmium, at doses relevant to human exposure, inhibited human mammary gland development, potentially through disruption of HIF-1 activity. These findings do not support cadmium being a breast cancer initiator via induction of stem cell proliferation, but instead implicate cadmium as an inhibitor of mammary gland morphogenesis.

pharmacology and toxicology↗