Browsing by Author "Singh A.K."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Bulbine frutescens phytochemical inhibits notch signaling pathway and induces apoptosis in triple negative and luminal breast cancer cells
    (Elsevier Inc., 2019) Kushwaha P.P.; Vardhan P.S.; Kapewangolo P.; Shuaib M.; Prajapati S.K.; Singh A.K.; Kumar S.
    Breast cancer (BCa) is the most commonly diagnosed lethal cancer in women worldwide. Notch signaling pathway is directly linked to BCa recurrence and aggressiveness. Natural remedies are becoming a prime choice to overcome against cancer due to lesser side effect and cost-effectiveness. Bulbine frutescens (Asphodelaceae), a traditional medicinal plant in South Africa possess bioactive flavonoids and terpenoids. Polar (methanol) and non-polar (hexane) B. frutescens plant extracts were prepared. GC–MS analysis revealed the differential presence of secondary metabolites in both methanolic and hexane extracts. We hereby first time evaluated the anticancer potential of B. frutescens methanolic and hexane extract in triple-negative and luminal BCa cells. B. frutescens extracts significantly decreased cell viability (IC50 4.8–28.4 μg/ml) and induced cell cycle arrest at G1 phase in MDA-MB-231 and T47D cells as confirmed by spectrophotometry and flow cytometry technique. RT-PCR analysis of cell cycle (cyclin D1, CDK4, and p21) and apoptosis modulating genes (caspase 3, Bcl2 and survivin) revealed upexpression of p21, and caspase 3, and down expression of cyclin D1, CDK4, Bcl2 and survivin genes in extract-treated BCa cells. Fluorescence spectrophotometry and confocal microscopy showed B. frutescens induced nuclear morphology and mitochondrial integrity disruption, and increased reactive oxygen species production in MDA-MB-231 and T47D cells. Flow cytometric apoptosis analysis of B. frutescens extracts treated MDA-MB-231 cells showed ≈13% increase in early apoptotic population in comparison to non-treated cells. Dual-Luciferase Reporter assay confirmed notch promoter inhibitory activity of B. frutescens extracts. Moreover, RTPCR analysis showed down regulation of notch responsive genes (Hes1 and Hey1) at transcription levels in extract-treated BCa cells. Western Blot analysis showed increased procaspase 3 protein expression in extract-treated BCa cells. In all the assays methanolic extract showed better anti-cancer properties. Literature-based identification of methanol soluble phytochemicals in B. frutescens and in silico docking study revealed Bulbineloneside D as a potent ϒ-secretase enzyme inhibitor. In comparison to standard notch inhibitor, lead phytochemical showed two additional hydrophobic interactions with Ala80 and Leu81 amino acids. In conclusion, B. frutescens phytochemicals have cell cycle arrest, ROS production, apoptosis induction, and mitochondria membrane potential disruption efficacy in breast cancer cells. B. frutescens phytochemicals have the ability to downregulate the notch signaling pathway in triple-negative and luminal breast cancer cells.
  • No Thumbnail Available
    Item
    MicroRNA Targeting Nicotinamide Adenine Dinucleotide Phosphate Oxidases in Cancer
    (Mary Ann Liebert Inc., 2020) Kushwaha P.P.; Gupta S.; Singh A.K.; Prajapati K.S.; Shuaib M.; Kumar S.
    Significance: Reactive oxygen species (ROS) production occurs primarily in the mitochondria as a by-product of cellular metabolism. ROS are also produced by nicotinamide adenine dinucleotide phosphate (NADPH) oxidases in response to growth factors and cytokines by normal physiological signaling pathways. NADPH oxidase, a member of NADPH oxidase (NOX) family, utilizes molecular oxygen (O2) to generate ROS such as hydrogen peroxide and superoxide. Imbalance between ROS production and its elimination is known to be the major cause of various human diseases. NOX family proteins are exclusively involved in ROS production, which makes them attractive target(s) for the treatment of ROS-mediated diseases including cancer. Recent Advances: Molecules such as Keap1/nuclear factor erythroid 2-related factor 2 (Nrf2), N-methyl-d-aspartic acid (NMDA) receptors, nuclear factor-kappaB, KRAS, kallistatin, gene associated with retinoic-interferon-induced mortality-19, and deregulated metabolic pathways are involved in ROS production in association with NADPH oxidase. Critical Issues: Therapeutic strategies targeting NADPH oxidases in ROS-driven cancers are not very effective due to its complex regulatory circuit. Tumor suppressor microRNAs (miRNAs) viz. miR-34a, miR-137, miR-99a, and miR-21a-3p targeting NADPH oxidases are predominantly downregulated in ROS-driven cancers. miRNAs also regulate other cellular machineries such as Keap1/Nrf2 pathway and NMDA receptors involved in ROS production and consequently drug resistance. Here, we discuss the structure, function, and metabolic role of NADPH oxidase, NOX family protein-protein interaction, their association with other pathways, and NADPH oxidase alteration by miRNAs. Moreover, we also discuss and summarize studies on NADPH oxidase associated with various malignancies and their therapeutic implications. Future Directions: Targeting NADPH oxidases through miRNAs appears to be a promising strategy for the treatment of ROS-driven cancer.