Induction of Paraptotic Cell Death in Breast Cancer Cells by a Novel Pyrazolo[3,4-h]quinoline Derivative through ROS Production and Endoplasmic Reticulum Stress

Chemotherapy has been a standard intervention for a variety of cancers to impede tumor growth, mainly by inducing apoptosis. However, development of resistance to this regimen has led to a growing interest and demand for drugs targeting alternative cell death modes, such as paraptosis. Here, we designed and synthesized a novel derivative of a pyrazolo[3,4-h]quinoline scaffold (YRL1091), evaluated its cytotoxic effect, and elucidated the underlying molecular mechanisms of cell death in MDA-MB-231 and MCF-7 breast cancer (BC) cells. We found that YRL1091 induced cytotoxicity in these cells with numerous cytoplasmic vacuoles, one of the distinct characteristics of paraptosis. YRL1091-treated BC cells displayed several other distinguishing features of paraptosis, excluding autophagy or apoptosis. Briefly, YRL1091-induced cell death was associated with upregulation of microtubule-associated protein 1 light chain 3B, downregulation of multifunctional adapter protein Alix, and activation of extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase. Furthermore, the production of reactive oxygen species (ROS) and newly synthesized proteins were also observed, subsequently causing ubiquitinated protein accumulation and endoplasmic reticulum (ER) stress. Collectively, these results indicate that YRL1091 induces paraptosis in BC cells through ROS generation and ER stress. Therefore, YRL1091 can serve as a potential candidate for the development of a novel anticancer drug triggering paraptosis, which may provide benefit for the treatment of cancers resistant to conventional chemotherapy.

Investigation of the Optical Properties of a Novel Class of Quinoline Derivatives and Their Random Laser Properties Using ZnO Nanoparticles

Quinoline Schiff bases display potential applications in optoelectronics and laser fields because of their unique optical properties that arise from extensive delocalization of the electron cloud, and a high order of non-linearity. In this context, a new class of conjugated quinoline-derivative viz. N-(quinolin-3-ylmethylene)anilines were synthesized from 2-hydroxyquinoline-3-carbaldehyde in two good yielding steps. The ability of these imines to accept an electron from a donor is denoted by their electron acceptor number and sites, which is calculated using density functional theory (DFT). The optical properties such as FT-IR, Raman, UV-VIS, and EDS spectra were calculated using TD-DFT, which also provided the energy gap, HOMO-LUMO structure. The optical properties of the synthesized imino quinolines were experimentally studied using photoluminescence and absorption spectroscopy. The properties such as Stokes shift and quantum yield were calculated using experimental data. Furthermore, the compound bearing a methyl group on the aryl ring and ZnO nanoparticles (hydrothermally synthesized) were dissolved in toluene, and optically excited with a 355 nm nanosecond laser, which produced a random laser.

Investigations on Corrosion Inhibitory Effect of Newly Quinoline Derivative on Mild Steel in HCl Solution Complemented with Antibacterial Studies

This study analyzed the corrosion inhibitory effects and the antibacterial action of the quinoline derivative, namely N'-(2-hydroxybenzylidene)-2-(quinolin-8-yloxy)acetohydrazide (NHQA). NHQA prevention of corrosion behavior was investigated using weight loss experiments on mild steel coupons in hydrochloric acid. Weight loss tests achieved improved inhibition performance for NHQA, and the high inhibitor efficiency was reached at 303 K, of 93.4 percent at 500 ppm NHQA. Moreover, the effect of immersion time on carbon steel corrosion was investigated using strategies for weight loss. The NHQA mechanism for corrosion inhibition was also examined. These findings confirm that the NHQA molecules can be used in industrial applications as a possible corrosion inhibitor. In an aqueous solution, the synthesized compound (NHQA) can also be used as an antimicrobial agent. The microbial inhibitive efficacy of NHQA against Gram-positive (Staphyloccocus aureus) and Gram-negative bacteria (Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae, and Pseudomonas aeruginosa) was evaluated employee a disc diffusion technique. NHQA has considerable inhibition efficacy toward all investigated bacteria.

EFFLUX PUMP OVEREXPRESSION PROFILING IN ACINETOBACTER BAUMANNII AND STUDY OF NEW 1-(1-NAPHTHYLMETHYL)-PIPERAZINE ANALOGS AS POTENTIAL EFFLUX INHIBITORS

Overexpression of efflux pumps extruding antibiotics currently used for the treatment of Acinetobacter baumannii infections has been described as an important mechanism causing antibiotic resistance. The first aim of this work was to phenotypically evaluate the overexpression of efflux pumps on a collection of 124 ciprofloxacin resistant A. baumannii strains. An overexpression of genes encoding one or more efflux pumps was obtained for 19 out of the 34 strains with a positive phenotypic efflux (56%). The most frequent genes overexpressed were those belonging to the RND family, with adeJ being the most prevalent (50%). Interestingly, efflux pump genes coding for MATE and MFS families were also overexpressed quite frequently: abeM (32%) and abaQ (26%). The second aim was to synthesize 1-(1-NaphthylMethyl)-Piperazine analogs as potential new efflux pump inhibitors and biologically evaluate them against strains with a positive phenotypic efflux. Quinoline and pyridine analogs were found to be more effective than their parent compound 1-(1-NaphthylMethyl)-Piperazine. Stereochemistry also played an important part in the inhibitory activity as quinoline derivative ( R )-3a was identified as being the most effective and less cytotoxic. Its inhibitory activity was also correlated to the number of efflux pumps expressed by a strain. The results obtained in this work suggest that quinoline analogs of 1-(1-NaphthylMethyl)-Piperazine are promising leads in the development of new anti- Acinetobacter baumannii therapeutic alternatives, in combination with antibiotics for which an efflux-mediated resistance is suspected.

An 8-Hydroxy-Quinoline Derivative Protects Against Lipopolysaccharide-Induced Lethality in Endotoxemia by Inhibiting HMGB1-Mediated Caspase-11 Signaling

Sepsis, an inflammatory syndrome secondary to infection, is the leading cause of in-hospital lethality. It is evidenced that LPS, the major pathological component of the Gram-negative bacteria membrane, predominantly contributes to the pathogenesis of sepsis. Cytoplasmic lipopolysaccharide (LPS) can be sensed by the noncanonical inflammasome and triggers the oligomerization of caspase-11, resulting in pyroptosis and lethal immune responses in sepsis. A previous study has shown that hepatocyte-released high mobility group box 1 (HMGB1) mediates caspase-11–dependent lethality in sepsis by delivering extracellular LPS into the cytosol. Here, we established a phenotypic screening system using recombinant HMGB1 plus LPS in mouse peritoneal macrophages, identifying a novel 8-hydroxyquinoline derivative named 7-[phenyl (pyridin-2-ylamino) methyl] quinolin-8-ol (8-ol, NSC84094) that can specifically inhibit HMGB1-mediated caspase-11 signaling. 8-ol targets directly to HMGB1 and changes the secondary conformation, consequently disrupting the interaction between LPS and HMGB1 and inhibiting the HMGB1-mediated delivery of LPS into the cytosol. Intervention of 8-ol significantly reduced the release of IL-1α and IL-1β and protected against caspase-11–mediated organ injury and lethality in endotoxemic mice. Thus, this study clearly suggests that the HMGB1–caspase-11 pathway is a potential drug target in lethal immune disorders and might open a new avenue in the treatment of sepsis.

Quinoline-3-Carboxylic Acids “DNA Minor Groove-Binding Agent

Background: The lead compounds from the series of 2, 4-disubstituted quinoline-3-carboxylic acid derivatives were selected for the in-silico mechanistic study. The compounds were found selective and potent for the cancer cell. Moreover, the relevant ADME in-silico data also support the safety of lead. Objective- The objective of the study is to correlate the interaction of DNA and quinoline derivative, which was reported with the fluorescence microscopy images of cells in-vitro data in the recently published data. Methods: The detailed interaction study with the DNA dodecanucleotide sequenced d(CGCGAATTCGCG) shows the present lead bounds with the A/T minor groove region of a B-DNA duplex through important major and minor hydrogen-bonds. Result: The present in-silico study supports the interactions of the drug with DNA with sufficient binding interactions and energy. The present study also gives vital information related to the mechanism of drug action, which was initially declared as a DNA targeting molecule through a fluorescence based target study. Conclusion: The substitution at 2nd position (the carbonyl group) of the lead was revealed as a hydrogen bond donor/acceptor for the adenine and guanine nucleic acid-base pair. The in-silico prediction also confirmed the interaction pattern of the lead with the DNA, which will be further utilized for drug development.