Displaying publications 1941 - 1960 of 3312 in total

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  1. Fulltext Bioactivities of Lyngbyabellins from Cyanobacteria of Moorea and Okeania Genera
    Fathoni I, Petitbois JG, Alarif WM, Abdel-Lateff A, Al-Lihaibi SS, Yoshimura E, et al.
    Molecules, 2020 Sep 01;25(17).
    PMID: 32882989 DOI: 10.3390/molecules25173986
    Cyanobacteria are reported as rich sources of secondary metabolites that provide biological activities such as enzyme inhibition and cytotoxicity. Ten depsipeptide derivatives (lyngbyabellins) were isolated from a Malaysian Moorea bouillonii and a Red Sea Okeania sp.: lyngbyabellins G (1), O (2), P (3), H (4), A (7), 27-deoxylyngbyabellin A (5), and homohydroxydolabellin (6). This study indicated that lyngbyabellins displayed cytotoxicity, antimalarial, and antifouling activities. The isolated compounds were tested for cytotoxic effect against human breast cancer cells (MCF7), for antifouling activity against Amphibalanus amphitrite barnacle larvae, and for antiplasmodial effect towards Plasmodium falciparum. Lyngbyabellins A and G displayed potent antiplasmodial effect against Plasmodium, whereas homohydroxydolabellin showed moderate effect. For antifouling activity, the side chain decreases the activity slightly, but the essential feature is the acyclic structure. As previously reported, the acyclic lyngbyabellins are less cytotoxic than the corresponding cyclic ones, and the side chain increases cytotoxicity. This study revealed that lyngbyabellins, despite being cytotoxic agents as previously reported, also exhibit antimalarial and antifouling activities. The unique chemical structures and functionalities of lyngbyabellin play an essential role in their biological activities.
    Matched MeSH terms: MCF-7 Cells
  2. Fulltext Anticancer Molecular Mechanism of Protocatechuic Acid Loaded on Folate Coated Functionalized Graphene Oxide Nanocomposite Delivery System in Human Hepatocellular Carcinoma
    Buskaran K, Bullo S, Hussein MZ, Masarudin MJ, Mohd Moklas MA, Fakurazi S
    Materials (Basel), 2021 Feb 09;14(4).
    PMID: 33572054 DOI: 10.3390/ma14040817
    Liver cancer is listed as the fifth-ranked cancer, responsible for 9.1% of all cancer deaths globally due to its assertive nature and poor survival rate. To overcome this obstacle, efforts have been made to ensure effective cancer therapy via nanotechnology utilization. Recent studies have shown that functionalized graphene oxide (GO)-loaded protocatechuic acid has shown some anticancer activities in both passive and active targeting. The nanocomposites' physicochemical characterizations were conducted. A lactate dehydrogenase experiment was conducted to estimate the severity of cell damage. Subsequently, a clonogenic assay was carried out to examine the colony-forming ability during long-term exposure of the nanocomposites. The Annexin V/ propidium iodide analysis showed that nanocomposites induced late apoptosis in HepG2 cells. Following the intervention of nanocomposites, cell cycle arrest was ascertained at G2/M phase. There was depolarization of mitochondrial membrane potential and an upregulation of reactive oxygen species when HepG2 cells were induced by nanocomposites. Finally, the proteomic profiling array and quantitative reverse transcription polymerase chain reaction revealed the expression of pro-apoptotic and anti-apoptotic proteins induced by graphene oxide conjugated PEG loaded with protocatechuic acid drug folic acid coated nanocomposite (GOP-PCA-FA) in HepG2 cells. In conclusion, GOP-PCA-FA nanocomposites treated HepG2 cells exhibited significant anticancer activities with less toxicity compared to pristine protocatechuic acid and GOP-PCA nanocomposites, due to the utilization of a folic acid-targeting nanodrug delivery system.
    Matched MeSH terms: Hep G2 Cells
  3. Japanese encephalitis virus disrupts blood-brain barrier and modulates apoptosis proteins in THBMEC cells
    Al-Obaidi MMJ, Bahadoran A, Har LS, Mui WS, Rajarajeswaran J, Zandi K, et al.
    Virus Res, 2017 04 02;233:17-28.
    PMID: 28279803 DOI: 10.1016/j.virusres.2017.02.012
    Japanese encephalitis (JE) is a neurotropic flavivirus that causes inflammation in central nervous system (CNS), neuronal death and also compromises the structural and functional integrity of the blood-brain barrier (BBB). The aim of this study was to evaluate the BBB disruption and apoptotic process in Japanese encephalitis virus (JEV)-infected transfected human brain microvascular endothelial cells (THBMECs). THBMECs were overlaid by JEV with different MOIs (0.5, 1.0, 5.0 and 10.0) and monitored by electrical cell-substrate impedance sensing (ECIS) in a real-time manner in order to observe the barrier function of THBMECs. Additionally, the level of 43 apoptotic proteins was quantified in the virally infected cells with different MOIs at 24h post infection. Infection of THBMEC with JEV induced an acute reduction in transendothelial electrical resistance (TEER) after viral infection. Also, significant up-regulation of Bax, BID, Fas and Fasl and down-regulation of IGFBP-2, BID, p27 and p53 were observed in JEV infected THBMECs with 0.5 and 10 MOIs compared to uninfected cells. Hence, the permeability of THBMECs is compromised during the JEV infection. In addition high viral load of the virus has the potential to subvert the host cell apoptosis to optimize the course of viral infection through deactivation of pro-apoptotic proteins.
    Matched MeSH terms: Vero Cells; Endothelial Cells/metabolism*; Endothelial Cells/virology
  4. Insight into delivery of dermal fibroblast by non-biodegradable bacterial nanocellulose composite hydrogel on wound healing
    Loh EYX, Fauzi MB, Ng MH, Ng PY, Ng SF, Mohd Amin MCI
    Int J Biol Macromol, 2020 Sep 15;159:497-509.
    PMID: 32387606 DOI: 10.1016/j.ijbiomac.2020.05.011
    In skin tissue engineering, a biodegradable scaffold is usually used where cells grow, produce its own cytokines, growth factors, and extracellular matrix, until the regenerated tissue gradually replaces the scaffold upon its degradation. However, the role of non-biodegradable scaffold remains unexplored. This study investigates the potential of a non-biodegradable bacterial nanocellulose/acrylic acid (BNC/AA) hydrogel to transfer human dermal fibroblasts (HDF) to the wound and the resulting healing effects of transferred HDF in athymic mice. Results demonstrated that the fabricated hydrogel successfully transferred >50% of HDF onto the wound site within 24 h, with evidence of HDF detected on day 7. The gene and protein study unveiled faster wound healing in the hydrogel with HDF group and characterized more mature newly formed skin microstructure on day 7, despite no visible differences. These findings give a new perspective regarding the role of non-biodegradable materials in skin tissue engineering, in the presence of exogenous cells, mainly at the molecular level.
    Matched MeSH terms: Cells, Cultured
  5. C-terminal splice variants of P/Q-type Ca2+ channel CaV2.1 α1 subunits are differentially regulated by Rab3-interacting molecule proteins
    Hirano M, Takada Y, Wong CF, Yamaguchi K, Kotani H, Kurokawa T, et al.
    J Biol Chem, 2017 06 02;292(22):9365-9381.
    PMID: 28377503 DOI: 10.1074/jbc.M117.778829
    Voltage-dependent Ca2+ channels (VDCCs) mediate neurotransmitter release controlled by presynaptic proteins such as the scaffolding proteins Rab3-interacting molecules (RIMs). RIMs confer sustained activity and anchoring of synaptic vesicles to the VDCCs. Multiple sites on the VDCC α1 and β subunits have been reported to mediate the RIMs-VDCC interaction, but their significance is unclear. Because alternative splicing of exons 44 and 47 in the P/Q-type VDCC α1 subunit CaV2.1 gene generates major variants of the CaV2.1 C-terminal region, known for associating with presynaptic proteins, we focused here on the protein regions encoded by these two exons. Co-immunoprecipitation experiments indicated that the C-terminal domain (CTD) encoded by CaV2.1 exons 40-47 interacts with the α-RIMs, RIM1α and RIM2α, and this interaction was abolished by alternative splicing that deletes the protein regions encoded by exons 44 and 47. Electrophysiological characterization of VDCC currents revealed that the suppressive effect of RIM2α on voltage-dependent inactivation (VDI) was stronger than that of RIM1α for the CaV2.1 variant containing the region encoded by exons 44 and 47. Importantly, in the CaV2.1 variant in which exons 44 and 47 were deleted, strong RIM2α-mediated VDI suppression was attenuated to a level comparable with that of RIM1α-mediated VDI suppression, which was unaffected by the exclusion of exons 44 and 47. Studies of deletion mutants of the exon 47 region identified 17 amino acid residues on the C-terminal side of a polyglutamine stretch as being essential for the potentiated VDI suppression characteristic of RIM2α. These results suggest that the interactions of the CaV2.1 CTD with RIMs enable CaV2.1 proteins to distinguish α-RIM isoforms in VDI suppression of P/Q-type VDCC currents.
    Matched MeSH terms: HEK293 Cells
  6. Fulltext Punicalagin Regulates Apoptosis-Autophagy Switch via Modulation of Annexin A1 in Colorectal Cancer
    Ganesan T, Sinniah A, Chik Z, Alshawsh MA
    Nutrients, 2020 Aug 13;12(8).
    PMID: 32823596 DOI: 10.3390/nu12082430
    Punicalagin (PU), a polyphenol extracted from pomegranate (Punica granatum) husk is proven to have anti-cancer effects on different types of cancer including colorectal cancer (CRC). Its role in modulating endogenous protein as a means of eliciting its anti-cancer effects, however, has not been explored to date. Hence, this study aimed to investigate the role of PU in modulating the interplay between apoptosis and autophagy by regulating Annexin A1 (Anx-A1) expression in HCT 116 colorectal adenocarcinoma cells. In the study, selective cytotoxicity, pro-apoptotic, autophagic and Anx-A1 downregulating properties of PU were shown which indicate therapeutic potential that this polyphenol has against CRC. Autophagy flux analysis via flow cytometry showed significant autophagosomes degradation in treated cells, proving the involvement of autophagy. Proteome profiling of 35 different proteins in the presence and absence of Anx-A1 antagonists in PU-treated cells demonstrated a complex interplay that happens between apoptosis and autophagy that suggests the possible simultaneous induction and inhibition of these two cell death mechanisms by PU. Overall, this study suggests that PU induces autophagy while maintaining basal level of apoptosis as the main mechanisms of cytotoxicity via the modulation of Anx-A1 expression in HCT 116 cells, and thus has a promising translational potential.
    Matched MeSH terms: HCT116 Cells
  7. Fulltext Lung-infiltrating T helper 17 cells as the major source of interleukin-17A production during pulmonary Cryptococcus neoformans infection
    Movahed E, Cheok YY, Tan GMY, Lee CYQ, Cheong HC, Velayuthan RD, et al.
    BMC Immunol, 2018 Nov 08;19(1):32.
    PMID: 30409128 DOI: 10.1186/s12865-018-0269-5
    BACKGROUND: IL-17A has emerged as a key player in the pathologies of inflammation, autoimmune disease, and immunity to microbes since its discovery two decades ago. In this study, we aim to elucidate the activity of IL-17A in the protection against Cryptococcus neoformans, an opportunistic fungus that causes fatal meningoencephalitis among AIDS patients. For this purpose, we examined if C. neoformans infection triggers IL-17A secretion in vivo using wildtype C57BL/6 mice. In addition, an enhanced green fluorescence protein (EGFP) reporter and a knockout (KO) mouse models were used to track the source of IL-17A secretion and explore the protective function of IL-17A, respectively.

    RESULTS: Our findings showed that in vivo model of C. neoformans infection demonstrated induction of abundant IL-17A secretion. By examining the lung bronchoalveolar lavage fluid (BALF), mediastinal lymph node (mLN) and spleen of the IL-17A-EGFP reporter mice, we showed that intranasal inoculation with C. neoformans promoted leukocytes lung infiltration. A large proportion (~ 50%) of the infiltrated CD4+ helper T cell population secreted EGFP, indicating vigorous TH17 activity in the C. neoformans-infected lung. The infection study in IL-17A-KO mice, on the other hand, revealed that absence of IL-17A marginally boosted fungal burden in the lung and accelerated the mouse death.

    CONCLUSION: Therefore, our data suggest that IL-17A is released predominantly from TH17 cells in vivo, which plays a supporting role in the protective immunity against C. neoformans infection.

    Matched MeSH terms: Th17 Cells
  8. Improved DNA Delivery Efficiency of Bacterial Vectors by Co-Delivery with Exogenous Lipid and Antimicrobial Reagents
    Osahor AN, Narayanan K
    Methods Mol Biol, 2021;2211:15-27.
    PMID: 33336267 DOI: 10.1007/978-1-0716-0943-9_2
    Gene delivery using invasive bacteria as vectors is a robust method that is feasible for plasmid and artificial chromosome DNA construct delivery to human cells presenting β1 integrin receptors. This technique is relatively underutilized owing to the inefficiency of gene transfer to targeted cell populations. Bacterial vectors must successfully adhere to the cell membrane, internalize into the cytoplasm, undergo lysis, and deliver DNA to the nucleus. There are limited studies on the use of exogenous reagents to improve the efficiency of bacteria-mediated gene delivery to mammalian cells. In this chapter, we describe how cationic lipids, conventionally used for DNA and protein transfection, as well as antimicrobial compounds, can be used to synergistically enhance the adherence of invasive bacterial vectors to the cell membrane and improve their predisposition to internalize into the cytoplasm to deliver DNA. Using simple combinatorial methods, functional DNA transfer can be improved by up to four-fold of invaded cell populations. These methods are easy to perform and are likely to be applicable for other bacterial vectors including Listeria and Salmonella.
    Matched MeSH terms: Cells, Cultured
  9. Fulltext Increased fucoxanthin in Chaetoceros calcitrans extract exacerbates apoptosis in liver cancer cells via multiple targeted cellular pathways
    Foo SC, Yusoff FM, Imam MU, Foo JB, Ismail N, Azmi NH, et al.
    Biotechnol Rep (Amst), 2019 Mar;21:e00296.
    PMID: 30581767 DOI: 10.1016/j.btre.2018.e00296
    In this study, anti-proliferative effects of C. calcitrans extract and its fucoxanthin rich fraction (FxRF) were assessed on human liver HepG2 cancer cell line. Efficacy from each extract was determined by cytotoxicity assay, morphological observation, and cell cycle analysis. Mechanisms of action observed were evaluated using multiplex gene expression analysis. Results showed that CME and FxRF induced cytotoxicity to HepG2 cells in a dose and time-dependent manner. FxRF (IC50: 18.89 μg.mL-1) was found to be significantly more potent than CME (IC50: 87.5 μg.mL-1) (p 
    Matched MeSH terms: Hep G2 Cells
  10. Dietary cocoa inhibits colitis associated cancer: a crucial involvement of the IL-6/STAT3 pathway
    Saadatdoust Z, Pandurangan AK, Ananda Sadagopan SK, Mohd Esa N, Ismail A, Mustafa MR
    J Nutr Biochem, 2015 Dec;26(12):1547-58.
    PMID: 26355019 DOI: 10.1016/j.jnutbio.2015.07.024
    Patients with inflammatory bowel disease (IBD) are at increased risk for developing ulcerative colitis-associated colorectal cancer (CRC). The interleukin-6 (IL-6)/signal transducer and activator of transcription (STAT)-3 signaling regulates survival and proliferation of intestinal epithelial cells and play an important role in the pathogenesis of IBD and CRC. Cocoa is enriched with polyphenols that known to possess antioxidant, anti-inflammatory and antitumor activities. Here, we explored the antitumor effects and mechanisms of cocoa diet on colitis-associated cancer (CAC) using the azoxymethane/dextran sulfate sodium model, with a particular focus on whether cocoa exerts its anticancer effect through the IL-6/STAT3 pathway. We found that cocoa significantly decreased the tumor incidence and size in CAC-induced mice. In addition to inhibiting proliferation of tumor epithelial cells, cocoa suppressed colonic IL-6 expression and subsequently activation of STAT3. Thus, our findings demonstrated that cocoa diet suppresses CAC tumorigenesis, and its antitumor effect is partly mediated by limiting IL-6/STAT3 activation. In addition, cocoa induces apoptosis by increased the expressions of Bax and caspase 3 and decreased Bcl-xl. Thus, we conclude that cocoa may be a potential agent in the prevention and treatment of CAC.
    Matched MeSH terms: Epithelial Cells
  11. Fulltext Fabrication of Adipose-Derived Stem Cell-Based Self-Assembled Scaffold under Hypoxia and Mechanical Stimulation for Urethral Tissue Engineering
    Rashidbenam Z, Jasman MH, Tan GH, Goh EH, Fam XI, Ho CCK, et al.
    Int J Mol Sci, 2021 Mar 25;22(7).
    PMID: 33805910 DOI: 10.3390/ijms22073350
    Long urethral strictures are often treated with autologous genital skin and buccal mucosa grafts; however, risk of hair ingrowth and donor site morbidity, restrict their application. To overcome this, we introduced a tissue-engineered human urethra comprising adipose-derived stem cell (ASC)-based self-assembled scaffold, human urothelial cells (UCs) and smooth muscle cells (SMCs). ASCs were cultured with ascorbic acid to stimulate extracellular matrix (ECM) production. The scaffold (ECM) was stained with collagen type-I antibody and the thickness was measured under a confocal microscope. Results showed that the thickest scaffold (28.06 ± 0.59 μm) was achieved with 3 × 104 cells/cm2 seeding density, 100 μg/mL ascorbic acid concentration under hypoxic and dynamic culture condition. The biocompatibility assessment showed that UCs and SMCs seeded on the scaffold could proliferate and maintain the expression of their markers (CK7, CK20, UPIa, and UPII) and (α-SMA, MHC and Smootheline), respectively, after 14 days of in vitro culture. ECM gene expression analysis showed that the ASC and dermal fibroblast-based scaffolds (control) were comparable. The ASC-based scaffold can be handled and removed from the plate. This suggests that multiple layers of scaffold can be stacked to form the urothelium (seeded with UCs), submucosal layer (ASCs only), and smooth muscle layer (seeded with SMCs) and has the potential to be developed into a fully functional human urethra for urethral reconstructive surgeries.
    Matched MeSH terms: Stem Cells
  12. Fulltext Diabetes-associated autoantibodies among young diabetes mellitus patients in Malaysia
    Hasni Mahayidin, Siti Zulaikha Zakariah, Noor Ashidah Ishah, Xu Ann Wee, Masita Arip, Nurhanani Mohamed Nor
    Malaysian Journal of Medicine and Health Sciences, 2020;16(2):118-125.
    MyJurnal
    Introduction: Diabetes-associated autoantibodies (DAA) is the hallmark of T1DM and LADA which are frequently tested in young diabetes patients. It was noted that up to 10-15% of patients with initial diagnosis of T2DM also exhibit DAA. Regardless of the classification, the presence of DAA suggests an underlying islet autoimmunity which lead to progressive pancreatic β-cell failure. There is limited data reported on DAA in young diabetes patients in Malaysia. This study aims to determine the frequency of DAA positivity and its association with demographic and clinical characteristics among this cohort. Methods: A retrospective study using secondary data obtained from Al- lergy and Immunology Research Centre, Institute for Medical Research, Malaysia. This study included 194 diabetes patients who were diagnosed before the age of 40 years old and tested for GADA, ICA, IA2A and IAA. Results: From 194 patients, 91 (46.9%) were positive for least one of the following DAA: ICA (79, 40.7%), GADA (61, 31.4%), IA2A (37, 19.1%) and IAA (9, 4.6%). Multiple positivity was higher (73.6%) compared to single positivity. Highest com- bination of double positivity was ICA+GADA (54, 59.3%) and triple positivity was ICA+GADA+IA2A (25, 27.5%). Simultaneous positivity of four autoantibodies was seen in only one (1.1%) patient. ICA, GADA and IA2A were asso- ciated with age group and ethnicity (all p < 0.001). Only IA2A was associated with gender (p = 0.012). Conclusions: GADA, ICA ad IA2A are more significant in young Malaysian diabetes patients. IAA has a very low frequency in this studied population.

    Matched MeSH terms: Insulin-Secreting Cells
  13. Fulltext Differential Response of Gestational Tissues to TLR3 Viral Priming Prior to Exposure to Bacterial TLR2 and TLR2/6 Agonists
    Rasheed ZBM, Lee YS, Kim SH, Rai RK, Ruano CSM, Anucha E, et al.
    Front Immunol, 2020;11:1899.
    PMID: 32983111 DOI: 10.3389/fimmu.2020.01899
    Background: Infection/inflammation is an important causal factor in spontaneous preterm birth (sPTB). Most mechanistic studies have concentrated on the role of bacteria, with limited focus on the role of viruses in sPTB. Murine studies support a potential multi-pathogen aetiology in which a double or sequential hit of both viral and bacterial pathogens leads to a higher risk preterm labour. This study aimed to determine the effect of viral priming on bacterial induced inflammation in human in vitro models of ascending and haematogenous infection. Methods: Vaginal epithelial cells, and primary amnion epithelial cells and myocytes were used to represent cell targets of ascending infection while interactions between peripheral blood mononuclear cells (PBMCs) and placental explants were used to model systemic infection. To model the effect of viral priming upon the subsequent response to bacterial stimuli, each cell type was stimulated first with a TLR3 viral agonist, and then with either a TLR2 or TLR2/6 agonist, and responses compared to those of each agonist alone. Immunoblotting was used to detect cellular NF-κB, AP-1, and IRF-3 activation. Cellular TLR3, TLR2, and TLR6 mRNA was quantified by RT-qPCR. Immunoassays were used to measure supernatant cytokine, chemokine and PGE2 concentrations. Results: TLR3 ("viral") priming prior to TLR2/6 agonist ("bacterial") exposure augmented the pro-inflammatory, pro-labour response in VECs, AECs, myocytes and PBMCs when compared to the effects of agonists alone. In contrast, enhanced anti-inflammatory cytokine production (IL-10) was observed in placental explants. Culturing placental explants in conditioned media derived from PBMCs primed with a TLR3 agonist enhanced TLR2/6 agonist stimulated production of IL-6 and IL-8, suggesting a differential response by the placenta to systemic inflammation compared to direct infection as a result of haematogenous spread. TLR3 agonism generally caused increased mRNA expression of TLR3 and TLR2 but not TLR6. Conclusion: This study provides human in vitro evidence that viral infection may increase the susceptibility of women to bacterial-induced sPTB. Improved understanding of interactions between viral and bacterial components of the maternal microbiome and host immune response may offer new therapeutic options, such as antivirals for the prevention of PTB.
    Matched MeSH terms: Epithelial Cells/drug effects; Epithelial Cells/immunology; Epithelial Cells/metabolism
  14. Fulltext Selective cytotoxicity effects of cytobiotics produced by lactic acid bacteria isolated from Malaysian foods
    Hooi Ling Foo
    Malaysian Journal of Medicine and Health Sciences, 2019;15(108):7-7.
    MyJurnal
    Probiotics are live microorganisms and when consumed in adequate amounts will confer health benefit on the host. Probiotic effects of Lactic Acid Bacteria (LAB) have been reported extensively, which rely generally on the viability of LAB cells. However, we have reported extensively the prominent probiotic effects of cell less postbiotics metabolites produced by various strains of Lactobacillus plantarum isolated from Malaysian foods on rats, poultry and pigs. L. plantarum is a major species of LAB. Despite the emerging evidence of anticancer properties of LAB, very limited information is available on the cytotoxic and antiproliferative activities of cytobiotic metabolites produced by LAB. Recently, we have documented the selective antiproliferative and cytotoxicity of cytobiotic produced by six strains of L. plantarum on normal human primary cells, breast, colorectal, cervical, liver and leukemia cancer cell lines via MTT assay, trypan blue exclusion method and BrdU assay. Haemolytic assay was used to determine the toxicity of cytobiotic using human and various animal red blood cells. The cytotoxicity mode was subsequently determined for selected UL4 cytobiotic on MCF-7 cells due to its pronounced cytotoxic effect by fluorescent microscopic ob-servation using AO/PI dye reagents and flow cytometric analyses. The selective cytotoxicity effect on various cancel cells that occurred in a strain-specific and cancer cell type-specific manner whilst sparing the normal cells will be discussed in the presentation. Moreover, the antiproliferative effects and induction of late apoptosis effects against selected malignant cancer cells will be discussed further in the presentation. This report reveals the vast potential of cytobiotics produced by L. plantarum strains as functional supplement and as an adjunctive treatment for cancer.
    Matched MeSH terms: MCF-7 Cells
  15. Fulltext Cytotoxic and anticancer properties of the Malaysian mangrove pit viper (Trimeresurus purpureomaculatus) venom and its disintegrin (purpureomaculin)
    Tan CH, Liew JL, Navanesan S, Sim KS, Tan NH, Tan KY
    J Venom Anim Toxins Incl Trop Dis, 2020;26:e20200013.
    PMID: 32742279 DOI: 10.1590/1678-9199-JVATITD-2020-0013
    Background: The Asiatic pit vipers from the Trimeresurus complex are medically important venomous snakes. These pit vipers are often associated with snakebite that leads to fatal coagulopathy and tissue necrosis. The cytotoxic venoms of Trimeresurus spp.; however, hold great potential for the development of peptide-based anticancer drugs.

    Methods: This study investigated the cytotoxic effect of the venom from Trimeresurus purpureomaculatus, the mangrove pit viper (also known as shore pit viper) which is native in Malaysia, across a panel of human cancer cell lines from breast, lung, colon and prostate as well as the corresponding normal cell lines of each tissue.

    Results: The venom exhibited dose-dependent cytotoxic activities on all cell lines tested, with median inhibition concentrations (IC50) ranging from 0.42 to 6.98 µg/mL. The venom has a high selectivity index (SI = 14.54) on breast cancer cell line (MCF7), indicating that it is significantly more cytotoxic toward the cancer than to normal cell lines. Furthermore, the venom was fractionated using C18 reversed-phase high-performance liquid chromatography and the anticancer effect of each protein fraction was examined. Fraction 1 that contains a hydrophilic low molecular weight (approximately 7.5 kDa) protein was found to be the most cytotoxic and selective toward the breast cancer cell line (MCF7). The protein was identified using liquid chromatography-tandem mass spectrometry as a venom disintegrin, termed purpureomaculin in this study.

    Conclusion: Taken together, the findings revealed the potent and selective cytotoxicity of a disintegrin protein isolated from the Malaysian T. purpureomaculatus venom and suggested its anticancer potential in drug discovery.

    Matched MeSH terms: MCF-7 Cells
  16. microRNA-548m suppresses cell migration and invasion by targeting aryl hydrocarbon receptor in breast cancer cells
    Nor WMFSBW, Chung I, Said NABM
    Oncol Res, 2020 Oct 27.
    PMID: 33109304 DOI: 10.3727/096504020X16037933185170
    Breast cancer is the most commonly diagnosed cancer among women and one of the leading causes of cancer mortality worldwide, in which the most severe form happens when it metastasizes to other regions of the body. Metastasis is responsible for most treatment failures in advanced breast cancer. Epithelial-mesenchymal transition (EMT) plays a significant role in promoting metastatic processes in breast cancer. MicroRNAs (miRNAs) are highly conserved endogenous short non-coding RNAs that play a role in regulating a broad range of biological processes, including cancer initiation and development, by functioning as tumor promoters or tumor suppressors. Expression of miR-548m has been found in various types of cancers, but the biological function and molecular mechanisms of miR-548m in cancers have not been fully studied. Here, we demonstrated the role of miR-548m in modulating EMT in the breast cancer cell lines MDA-MB-231 and MCF-7. Expression data for primary breast cancer obtained from NCBI GEO datasets showed that miR-548m expression was downregulated in breast cancer patients compared with healthy group. We hypothesize that miR-548m acts as a tumor suppressor in breast cancer. Overexpression of miR-548m in both cell lines increased E-cadherin expression and decreased the EMT-associated transcription factors SNAI1, SNAI2, ZEB1 and ZEB2, as well as MMP9 expression. Consequently, migration and invasion capabilities of both MDA-MB-231 and MCF-7 cells were significantly inhibited in miR-548m-overexpressing cells. Analysis of 1059 putative target genes of miR-548m revealed common pathways involving both tight junction and the mTOR signaling pathway, which has potential impacts on cell migration and invasion. Furthermore, this study identified aryl hydrocarbon receptor (AHR) as a direct target of miR-548m in breast cancer cells. Taken together, our findings suggest a novel function of miR-548m in reversing the EMT of breast cancer by reducing their migratory and invasive potentials, at least in part via targeting AHR expression.
    Matched MeSH terms: MCF-7 Cells
  17. Scrobiculosides A and B from the deep-sea sponge Pachastrella scrobiculosa
    Jomori T, Shiroyama S, Ise Y, Kohtsuka H, Matsuda K, Kuranaga T, et al.
    J Nat Med, 2019 Sep;73(4):814-819.
    PMID: 31054009 DOI: 10.1007/s11418-019-01315-6
    Two new steroidal saponins, scrobiculosides A and B, were isolated from the deep-sea sponge Pachastrella scrobiculosa, collected at a depth of 200 m off Miura Peninsula, Japan. The aglycones of scrobiculosides A and B feature a vinylic cyclopropane and a ∆24,25 exomethylene on the side chains, respectively. Both saponins have a common sugar moiety composed of β-D-galactopyranosyl-(1 → 2)-6-acetyl-β-D-glucopyranoside, with the exception of an acetyl group on C6″ in scrobiculoside A. Scrobiculoside A exhibited cytotoxicity against HL-60 and P388 cells, with IC50 values of 52 and 61 μM, respectively.
    Matched MeSH terms: HL-60 Cells
  18. Fulltext Annexin II Light Chain p11 Interacts With ENaC to Increase Functional Activity at the Membrane
    Cheung TT, Ismail NAS, Moir R, Arora N, McDonald FJ, Condliffe SB
    Front Physiol, 2019;10:7.
    PMID: 30800070 DOI: 10.3389/fphys.2019.00007
    The epithelial Na+ channel (ENaC) provides for Na+ absorption in various types of epithelia including the kidney, lung, and colon where ENaC is localized to the apical membrane to enable Na+ entry into the cell. The degree of Na+ entry via ENaC largely depends on the number of active channels localized to the cell membrane, and is tightly controlled by interactions with ubiquitin ligases, kinases, and G-proteins. While regulation of ENaC endocytosis has been well-studied, relatively little is understood of the proteins that govern ENaC exocytosis. We hypothesized that the annexin II light chain, p11, could participate in the transport of ENaC along the exocytic pathway. Our results demonstrate that all three ENaC channel subunits interacted with p11 in an in vitro binding assay. Furthermore, p11 was able to immunoprecipitate ENaC in epithelial cells. Quantitative mass spectrometry of affinity-purified ENaC-p11 complexes recovered several other trafficking proteins including HSP-90 and annexin A6. We also report that p11 exhibits a robust protein expression in cortical collecting duct epithelial cells. However, the expression of p11 in these cells was not influenced by either short-term or long-term exposure to aldosterone. To determine whether the p11 interaction affected ENaC function, we measured amiloride sensitive Na+ currents in Xenopus oocytes or mammalian epithelia co-expressing ENaC and p11 or a siRNA to p11. Results from these experiments showed that p11 significantly augmented ENaC current, whereas knockdown of p11 decreased current. Further, knockdown of p11 reduced ENaC cell surface population suggesting p11 promotes membrane insertion of ENaC. Overall, our findings reveal a novel protein interaction that controls the number of ENaC channels inserted at the membrane via the exocytic pathway.
    Matched MeSH terms: Epithelial Cells
  19. Chitosan based thermosensitive injectable hydrogels for controlled delivery of loxoprofen: development, characterization and in-vivo evaluation
    Ahmad U, Sohail M, Ahmad M, Minhas MU, Khan S, Hussain Z, et al.
    Int J Biol Macromol, 2019 May 15;129:233-245.
    PMID: 30738157 DOI: 10.1016/j.ijbiomac.2019.02.031
    Oral drug delivery is natural, most acceptable and desirable route for nearly all drugs, but many drugs like NSAIDs when delivered by this route cause gastrointestinal irritation, gastric bleeding, ulcers, and many undesirable effects which limits their usage by oral delivery. Moreover, it is almost impossible to control the release of a drug in a targeted location in body. We developed thermo-responsive chitosan-co-poly(N-isopropyl-acrylamide) injectable hydrogel as an alternative for the gastro-protective and controlled delivery of loxoprofen sodium as a model drug. A free radical polymerization technique was used to synthesize thermo-responsive hydrogel by cross-linking chitosan HCl with NIPAAM using glutaraldehyde as cross-linker. Confirmation of crosslinked hydrogel structure was done by Fourier transform infrared spectra (FTIR). The thermal stability of hydrogel was confirmed through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The scanning electron microscopy (SEM) was performed to evaluate the structural morphology of cross-linked hydrogel. To evaluate the rheological behavior of hydrogel with increasing temperature, rheological study was performed. Swelling and in vitro drug release studies were carried out under various temperature and pH conditions. The swelling study revealed that maximum swelling was observed at low pH (pH 1.2) and low temperature (25 °C) compared to the high range of pH and temperature and it resulted in quick release of the drug. The high range of pH (7.4) and temperature (37 °C) however caused controlled release of the drug. The in vivo evaluation of the developed hydrogel in rabbits demonstrated the controlled release behavior of fabricated system.
    Matched MeSH terms: Vero Cells
  20. In Vitro Cytotoxic Activity of Clinacanthus nutans Leaf Extracts Against HeLa Cells
    Haron NH, Md Toha Z, Abas R, Hamdan MR, Azman N, Khairuddean M, et al.
    Asian Pac J Cancer Prev, 2019 Feb 26;20(2):601-609.
    PMID: 30806066
    Objective: This study was conducted to investigate the antiproliferative activity of extracts of Clinacanthus nutans
    leaves against human cervical cancer (HeLa) cells. Methods: C. nutans leaves were subjected to extraction using 80%
    methanol or water. The methanol extract was further extracted to obtain hexane, dichloromethane (DCM), and aqueous
    fractions. The antiproliferative activity of the extracts against HeLa cells was determined. The most cytotoxic extract
    was furthered analyzed by apoptosis and cell cycle assays, and the phytochemical constituents were screened by gas
    chromatography-mass spectrometry (GC-MS). Results: All of the extracts were antiproliferative against HeLa cells, and
    the DCM fraction had the lowest IC50 value of 70 μg/mL at 48 h. Microscopic studies showed that HeLa cells exposed
    to the DCM fraction exhibited marked morphological features of apoptosis. The flow cytometry study also confirmed
    that the DCM fraction induced apoptosis in HeLa cells, with cell cycle arrest at the S phase. GC-MS analysis revealed
    the presence of at least 28 compounds in the DCM fraction, most of which were fatty acids. Conclusion: The DCM
    fraction obtained using the extraction method described herein had a lower IC50 value than those reported in previous
    studies that characterized the anticancer activity of C. nutans against HeLa cells.
    Matched MeSH terms: HeLa Cells
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