Pyrimidinone Associated Triazole Carboxamides: Synthesis, Characterization, Cytotoxicity and DNA Binding Studies

Background: Pyrimidinones and its derivatives are present in many anti-cancer agents. It has been reported that these substances were proven to have significant activities against different types of human cancers. The incorporation of [1,2,3]-triazole, a nitrogen-rich unit not only increases the efficacy but also increases the lipophilicity of the drug molecule. As our research was to synthesize newer molecules of effective cytotoxicity, we focused on pyrimidinone and [1,2,3]-triazoles systems, as important scaffolds with the expectation of potential cytotoxic properties. Methods: Novel series of [1,2,3]-triazole carboxamides (5a-j) were synthesized, starting from 3-(2- chloroethyl)-2-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrimidin-4-one. The structure of all the synthesized compounds was elucidated based on IR, 1H-NMR, 13C-NMR and LC-MS data. Compounds were focused for their in vitro cytotoxicity against A375 melanoma cancer cell lines, MDA-MB-231 breast cancer cell lines and HEK 293-Human embryonic kidney cell lines using colorimetric MTT assay. The potent compound was evaluated for the DNA binding studies. Results: Most of the Pyrimidinone conjugated [1,2,3]-triazole carboxamides found to be selective towards melanoma cancer cell lines than breast cancer cell lines. Compounds 5d, 5i and 5b were effective against A375 cancer cell lines and are found to be non-toxic against HEK 293-Human embryonic kidney cell lines. The potent compound 5d showed good intrinsic binding constant (Kb) value 3.12 x 103 M-1 in UV based DNA titration. Conclusion: Newly synthesized Pyrimidinone conjugated [1,2,3]-triazole carboxamide derivatives showed the significant cytotoxicity and the potent compound showed good intrinsic binding constant in UV based DNA titration.

GENE-38. IDH1MUT INDUCES N6-METHYLADENOSINE (m6A) RNA HYPERMETHYLATION VIA D-2-HG IN GLIOMA

INTRODUCTION IDH1 MUT confers slower tumor growth rates and improved prognoses for glioma patients, but the precise mechanisms underlying these clinically relevant benefits remain largely unknown. IDH1MUT gliomas produce high levels of D-2-HG, a putative oncometabolite that inhibits a range of α-ketoglutarate-dependent dioxygenases. D-2-HG-mediated inhibition of TET-family proteins involved in DNA demethylation is known to be a key driver leading to the oncogenic DNA hypermethylation phenotype (known as G-CIMP) seen in IDH1MUT gliomas. Recent evidence indicates that D-2-HG also functionally inhibits FTO and AlkBH5, two dioxygenases responsible for demethylation of RNA N6-methyladenosine (m6A) sites. This study sought to determine if D-2-HG mediates an increase in m6A content in IDH1MUT gliomas. METHODS Total RNA was isolated from patient tumor samples, patient-derived gliomaspheres, human embryonic kidney cell (HEK293T), normal human astrocyte (NHA), and U87 glioma model systems expressing either IDH1MUT or IDH1WT. Relative abundance of m6A modifications was determined both quantitatively and qualitatively using colorimetric ELISA-like assays and m6A-antibody dot blots, respectively. RESULTS Quantification of m6A abundance in IDH1MUT patient tumor samples and patient-derived gliomaspheres revealed an increase in m6A content compared to IDH1WT samples. Forced expression of IDH1MUT in HEK293T, NHA, and U87 cells increased intracellular D-2-HG content and global m6A abundance in purified RNA. Additionally, D-2-HG treatment of IDH1WT cell lines increased m6A abundance, including in IDH1WT gliomaspheres. Conversely, inhibition of D-2-HG generation in IDH1MUT cell lines decreased m6A abundance. Data will also be presented suggesting that increased m6A abundance is associated with decreased cellular proliferation. CONCLUSIONS These results indicate that increased intracellular D-2-HG arising in the context of IDH1MUT mediates increases in RNA m6A methylation in glioma. The association with m6A hypermethylation and reduced growth suggests that RNA methylation provides a novel therapeutic target.

Polyethylene Glycol-Coated Gold Nanoparticles as DNA and Atorvastatin Delivery Systems and Cytotoxicity Evaluation

The application of nanoscience and nanotechnology in medicine has been useful in the diagnosis, monitoring, and treatment of many diseases. Gold nanoparticles are commonly used for medical imaging studies, biosensors, drug delivery systems, and gene therapy. It has been reported that nanoparticles coated with specific polymers improve the biocompatibility and stability and decrease the cytotoxicity of the nanoparticles. In this work, we performed transfection studies of gold nanoparticles coated with polyethylene glycol, synthetized by two different methods, in a human embryonic kidney cell culture (HEK 293), by using plasmids pSV-β-Gal and pIRES2-EGFP. In addition, we also evaluated the cell uptake of a fluorescent drug (atorvastatin) using the synthetized gold nanoparticles as carriers. Furthermore, the study of cell viability after the interaction between these cells and the nanoparticles was performed. It was shown that the polyethylene glycol-coated gold nanoparticles presented transfection efficiency and cell uptake greater than 45% in each case. These results suggest that the synthetized gold nanoparticles coated with polyethylene glycol could be used successfully and safely as DNA and drug delivery systems.

One-Pot Aqueous Synthesis of Fluorescent Ag-In-Zn-S Quantum Dot/Polymer Bioconjugates for Multiplex Optical Bioimaging of Glioblastoma Cells

Cancer research has experienced astonishing advances recently, but cancer remains a major threat because it is one of the leading causes of death worldwide. Glioblastoma (GBM) is the most malignant brain tumor, where the early diagnosis is vital for longer survival. Thus, this study reports the synthesis of novel water-dispersible ternary AgInS2 (AIS) and quaternary AgInS2-ZnS (ZAIS) fluorescent quantum dots using carboxymethylcellulose (CMC) as ligand for multiplexed bioimaging of malignant glioma cells (U-87 MG). Firstly, AgInS2 core was prepared using a one-pot aqueous synthesis stabilized by CMC at room temperature and physiological pH. Then, an outer layer of ZnS was grown and thermally annealed to improve their optical properties and split the emission range, leading to core-shell alloyed nanostructures. Their physicochemical and optical properties were characterized, demonstrating that luminescent monodispersed AIS and ZAIS QDs were produced with average sizes of 2.2 nm and 4.3 nm, respectively. Moreover, the results evidenced that they were cytocompatible using in vitro cell viability assays towards human embryonic kidney cell line (HEK 293T) and U-87 MG cells. These AIS and ZAIS successfully behaved as fluorescent nanoprobes (red and green, resp.) allowing multiplexed bioimaging and biolabeling of costained glioma cells using confocal microscopy.

Anti-Oxiflammatory Profile of Date Extracts (Phoenix sylvestris)

Fruit of date palm (Phoenix sylvestrisL.) is edible and used as an anti-geriatric, anti-oxidant ethnomedicine. In this study, three different types ofdateextracts, methanolic, acidic ethanolic and basic ethanolicwere evaluated for their putative in vitro scavenging effects on reactive oxygen species (ROS), where scavenging of hydroxyl radicals (basic ethanolic>acidic ethanolic>methanolic), superoxide radicals (acidic ethanolic>basic ethanolic>methanolic), DPPH radicals (acidic ethanolic>methanolic>basic ethanolic), nitric oxide (NO) (methanolic>acidic ethanolic>basic ethanolic) and inhibition of lipid peroxidation (basic ethanolic>acidic ethanolic> methanolic) were found to occur in a dose dependent manner. Their flavonoid and phenolic contents proved to be the source of this potent free radical scavenging activity and indicated a direct correlation with their total anti-oxidant capacity. On human embryonic kidney cell line (HEK) and murine RAW macrophages, bacterial lipopolysaccharide (LPS) induced inflammation, the date extracts applied therapeutically, inhibit intracellular oxidative stress significantly. This reinstatement of cellular homeostasis presumably occurs via mitochondrial pathways.