Displaying publications 41 - 60 of 99 in total

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  1. Fulltext 13C based proteinogenic amino acid (PAA) and metabolic flux ratio analysis of Lactococcus lactis reveals changes in pentose phosphate (PP) pathway in response to agitation and temperature related stresses
    Azizan KA, Ressom HW, Mendoza ER, Baharum SN
    PeerJ, 2017;5:e3451.
    PMID: 28695065 DOI: 10.7717/peerj.3451
    Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To gain insights into cellular metabolism, 13C metabolic flux analysis and gas chromatography mass spectrometry (GC-MS) were used to measure the flux ratios of active pathways in the central metabolism of L. lactis when subjected to three conditions varying in temperature (30°C, 37°C) and agitation (with and without agitation at 150 rpm). Collectively, the concentrations of proteinogenic amino acids (PAAs) and free fatty acids (FAAs) were compared, and Pearson correlation analysis (r) was calculated to measure the pairwise relationship between PAAs. Branched chain and aromatic amino acids, threonine, serine, lysine and histidine were correlated strongly, suggesting changes in flux regulation in glycolysis, the pentose phosphate (PP) pathway, malic enzyme and anaplerotic reaction catalysed by pyruvate carboxylase (pycA). Flux ratio analysis revealed that glucose was mainly converted by glycolysis, highlighting the stability of L. lactis' central carbon metabolism despite different conditions. Higher flux ratios through oxaloacetate (OAA) from pyruvate (PYR) reaction in all conditions suggested the activation of pyruvate carboxylate (pycA) in L. lactis, in response to acid stress during exponential phase. Subsequently, more significant flux ratio differences were seen through the oxidative and non-oxidative pentose phosphate (PP) pathways, malic enzyme, and serine and C1 metabolism, suggesting NADPH requirements in response to environmental stimuli. These reactions could play an important role in optimization strategies for metabolic engineering in L. lactis. Overall, the integration of systematic analysis of amino acids and flux ratio analysis provides a systems-level understanding of how L. lactis regulates central metabolism under various conditions.
    Matched MeSH terms: Threonine
  2. Fulltext Natural sources, biological effects, and pharmacological properties of cynaroside
    Bouyahya A, Taha D, Benali T, Zengin G, El Omari N, El Hachlafi N, et al.
    Biomed Pharmacother, 2023 May;161:114337.
    PMID: 36812715 DOI: 10.1016/j.biopha.2023.114337
    Cynaroside is a flavonoid, isolated from several species belonging to the Apiaceae, Poaceae, Lamiaceae, Solanaceae, Zingiberaceae, Compositae and other families and it can be extracted from seeds, roots, stems, leaves, barks, flowers, fruits, aerial parts, and the whole plant of these species. This paper discloses the current state of knowledge on the biological/pharmacological effects and mode of action to better understand the numerous health benefits of cynaroside. Several research works revealed that cynaroside could have beneficial effects on various human pathologies. Indeed, this flavonoid exerts antibacterial, antifungal, antileishmanial, antioxidant, hepatoprotective, antidiabetic, anti-inflammatory, and anticancer effects. Additionally, cynaroside exhibits its anticancer effects by blocking MET/AKT/mTOR axis by decreasing the phosphorylation level of AKT, mTOR, and P70S6K. For antibacterial activity, cynaroside reduces biofilm development of Pseudomonas aeruginosa and Staphylococcus aureus. Moreover, the incidence of mutations leading to ciprofloxacin resistance in Salmonella typhimurium was reduced after the treatment with cynaroside. In addition, cynaroside inhibited the production of reactive oxygen species (ROS), which reduced the damage to mitochondrial membrane potential caused by hydrogen peroxide (H2O2). It also enhanced the expression of the anti-apoptotic protein Bcl-2 and lowered that of the pro-apoptotic protein Bax. Cynaroside abrogated the up-regulation of c-Jun N-terminal kinase (JNK) and p53 protein expression triggered by H2O2. All these findings suggest that cynaroside could be used to prevent certain human diseases.
    Matched MeSH terms: TOR Serine-Threonine Kinases
  3. Therapeutic Potential of Albumin Nanoparticles Encapsulated Visnagin in MDA-MB-468 Triple-Negative Breast Cancer Cells
    Alsrhani A, Elderdery AY, Alzahrani B, Alzerwi NAN, Althobiti MM, Rayzah M, et al.
    Molecules, 2023 Apr 04;28(7).
    PMID: 37049991 DOI: 10.3390/molecules28073228
    Breast cancer is among the most recurrent malignancies, and its prevalence is rising. With only a few treatment options available, there is an immediate need to search for better alternatives. In this regard, nanotechnology has been applied to develop potential chemotherapeutic techniques, particularly for cancer therapy. Specifically, albumin-based nanoparticles are a developing platform for the administration of diverse chemotherapy drugs owing to their biocompatibility and non-toxicity. Visnagin, a naturally derived furanochromone, treats cancers, epilepsy, angina, coughs, and inflammatory illnesses. In the current study, the synthesis and characterization of albumin visnagin (AV) nanoparticles (NPs) using a variety of techniques such as transmission electron microscopy, UV-visible, Fourier transform infrared, energy dispersive X-ray composition analysis, field emission scanning electron microscopy, photoluminescence, X-Ray diffraction, and dynamic light scattering analyses have been carried out. The MTT test, dual AO/EB, DCFH-DA, Annexin-V-FITC/PI, Propidium iodide staining techniques as well as analysis of apoptotic proteins, antioxidant enzymes, and PI3K/Akt/mTOR signaling analysis was performed to examine the NPs' efficacy to suppress MDA-MB-468 cell lines. The NPs decreased cell viability increased the amount of ROS in the cells, disrupted membrane integrity, decreased the level of antioxidant enzymes, induced cell cycle arrest, and activated the PI3K/Akt/mTOR signaling cascade, ultimately leading to cell death. Thus, AV NPs possesses huge potential to be employed as a strong anticancer therapy alternative.
    Matched MeSH terms: TOR Serine-Threonine Kinases
  4. Fulltext Oral hyperpigmented lesions--a case study
    Kwa SK, Gupta ED
    Aust Fam Physician, 2013 Jul;42(7):490-1.
    PMID: 23826603
    An overweight woman, aged 58 years, presented for follow up of hypertension, diabetes and dyslipidaemia. She was noted to have hyperpigmented brown macules on the inner surface of the lower lip and buccal mucosa (Figure 1). She stated that she had first noticed these lesions when aged in her 40s. Her mother died at age 58 years from gastric cancer with extensive metastases, and her brother died at age 45 years from colon cancer with spread to the liver and lungs.
    Matched MeSH terms: Protein-Serine-Threonine Kinases/genetics
  5. Mutations in the mammalian target of rapamycin pathway regulators NPRL2 and NPRL3 cause focal epilepsy
    Ricos MG, Hodgson BL, Pippucci T, Saidin A, Ong YS, Heron SE, et al.
    Ann Neurol, 2016 Jan;79(1):120-31.
    PMID: 26505888 DOI: 10.1002/ana.24547
    Focal epilepsies are the most common form observed and have not generally been considered to be genetic in origin. Recently, we identified mutations in DEPDC5 as a cause of familial focal epilepsy. In this study, we investigated whether mutations in the mammalian target of rapamycin (mTOR) regulators, NPRL2 and NPRL3, also contribute to cases of focal epilepsy.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  6. The role of mTOR signalling pathway in hypoxia-induced cognitive impairment
    Abdo Qaid EY, Zulkipli NN, Zakaria R, Ahmad AH, Othman Z, Muthuraju S, et al.
    Int J Neurosci, 2021 May;131(5):482-488.
    PMID: 32202188 DOI: 10.1080/00207454.2020.1746308
    Hypoxia has been associated with cognitive impairment. Many studies have investigated the role of mTOR signalling pathway in cognitive functions but its role in hypoxia-induced cognitive impairment remains controversial. This review aimed to elucidate the role of mTOR in the mechanisms of cognitive impairment that may pave the way towards the mechanistic understanding and therapeutic intervention of hypoxia-induced cognitive impairment. mTORC1 is normally regulated during mild or acute hypoxic exposure giving rise to neuroprotection, whereas it is overactivated during severe or chronic hypoxia giving rise to neuronal cells death. Thus, it is worth exploring the possibility of maintaining normal mTORC1 activity and thereby preventing cognitive impairment during severe or chronic hypoxia.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  7. Fulltext LRRK2 N551K and R1398H variants are protective in Malays and Chinese in Malaysia: A case-control association study for Parkinson's disease
    Gopalai AA, Lim JL, Li HH, Zhao Y, Lim TT, Eow GB, et al.
    Mol Genet Genomic Med, 2019 Nov;7(11):e604.
    PMID: 31487119 DOI: 10.1002/mgg3.604
    BACKGROUND: The LRRK2 gene is associated with Parkinson's disease (PD) as a number of mutations within the gene have been shown to be susceptibility factors. Studies on various global populations have determined that mutations such as G2019S, G2385R, and R1628P in LRRK2 increase the risk of developing PD while the N551K-R1398H haplotype is associated with conferring protection against developing PD. Here we report a study looking at the N551K and R1398H variants for the first time in the Malaysian population.

    METHODS: Cases (523) which conformed to the United Kingdom PD Brain Bank Criteria for PD were recruited through trained neurologists and age- and ethnically matched controls (491) were individuals free of any neurological disorder. The N551K and R1398H mutations were genotyped using the Taqman SNP genotyping assay.

    RESULTS: A significant protective association for N551K was found in those of Malay ancestry, with a protective trend seen for R1398H. A meta-analysis of Chinese individuals in this cohort with other published cohorts of Chinese ancestry indicated a significant protective role for N551K and R1398H.

    CONCLUSION: This study reports that the N551K-R1398H haplotype is also relevant to the Malaysian population, with a significant protective effect found in those of Malay and Chinese ancestries.

    Matched MeSH terms: Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics*
  8. Unveiling the connection: Long-chain non-coding RNAs and critical signaling pathways in breast cancer
    Thapa R, Afzal O, Gupta G, Bhat AA, Almalki WH, Alzarea SI, et al.
    Pathol Res Pract, 2023 Sep;249:154736.
    PMID: 37579591 DOI: 10.1016/j.prp.2023.154736
    Breast cancer is a complex and diverse condition that disrupts multiple signaling pathways essential for cell proliferation, survival, and differentiation. Recently, the significant involvement of long-chain non-coding RNAs (lncRNAs) in controlling key signaling pathways associated with breast cancer development has been discovered. This review aims to explore the interaction between lncRNAs and various pathways, including the AKT/PI3K/mTOR, Wnt/β-catenin, Notch, DNA damage response, TGF-β, Hedgehog, and NF-κB signaling pathways, to gain a comprehensive understanding of their roles in breast cancer. The AKT/PI3K/mTOR pathway regulates cell growth, survival, and metabolic function. Recent data suggests that specific lncRNAs can influence the functioning of this pathway, acting as either oncogenes or tumor suppressors. Dysregulation of this pathway is commonly observed in breast cancer cases. Moreover, breast cancer development has been associated with other pathways such as Wnt/β-catenin, Notch, TGF-β, Hedgehog, and NF-κB. Emerging studies have identified lncRNAs that modulate breast cancer's growth, progression, and metastasis by interacting with these pathways. To advance the development of innovative diagnostic tools and targeted treatment options, it is crucial to comprehend the intricate relationship between lncRNAs and vital signaling pathways in breast cancer. By fully harnessing the therapeutic potential of lncRNAs, there is a possibility of developing more effective and personalized therapy choices for breast cancer patients. Further investigation is necessary to comprehensively understand the role of lncRNAs within breast cancer signaling pathways and fully exploit their therapeutic potential.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  9. Nanocomposites of iron oxide, sodium alginate, and eugenol induce apoptosis via PI3K/Akt/mTOR signaling in Hep3 cells and in vivo hepatotoxicity in the zebrafish model
    Elderdery AY, Alzerwi NAN, Alzahrani B, Alsrhani A, Alsultan A, Rayzah M, et al.
    Int J Biol Macromol, 2024 Jan;256(Pt 2):127490.
    PMID: 37979758 DOI: 10.1016/j.ijbiomac.2023.127490
    Hepatic cancer is among the most recurrently detected malignancies worldwide and one of the main contributors to cancer-associated mortality. With few available therapeutic choices, there is an instant necessity to explore suitable options. In this aspect, Nanotechnology has been employed to explore prospective chemotherapeutic approaches, especially for cancer treatment. Nanotechnology is concerned with the biological and physical properties of nanoparticles in the therapeutic use of drugs. In the current work, formulation, and characterization of α-Fe2O3-Sodium Alginate-Eugenol nanocomposites (FSE NCs) using several approaches like SEM and TEM, UV-visible, FTIR, and PL spectroscopy, XRD, EDAX, and DLS studies have been performed. With an average size of 50 nm, the rhombohedral structure of NCs was identified. Further, their anticancer activity against Hep3B liver cancer cell lines has been performed by cell viability, dual staining, DCFH-DA, Annexin-V/-FITC/PI, cell cycle analysis methods, and PI3K/Akt/mTOR signaling proteins were studied to assess the anticancer effects of the NCs in Hep3B cells. Also, anti-cancer activity on animal modeling in-vivo using zebra fishes to hematological parameters, liver enzymes, and histopathology study effectiveness was noticed. Moreover, the NCs reduced the viability, elevated the ROS accumulation, diminished the membrane integrity, reduced the antioxidants, blocked the cell cycle, and triggered the PI3K/Akt/mTOR signaling axis that eventually resulted in cell death. As a result, FSE NCs possess huge potential for use as a possible anticancer candidate.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  10. Inhibition of transforming growth factor-β via the activin receptor-like kinase-5 inhibitor attenuates pulmonary fibrosis
    Koh RY, Lim CL, Uhal BD, Abdullah M, Vidyadaran S, Ho CC, et al.
    Mol Med Rep, 2015 May;11(5):3808-13.
    PMID: 25585520 DOI: 10.3892/mmr.2015.3193
    Idiopathic pulmonary fibrosis is a chronic pulmonary disease that is characterized by formation of scar tissue in lungs. Transforming growth factor-β (TGF-β) is considered an important cytokine in the pathogenesis of this disease. Hence, the antifibrotic effect of an inhibitor of the TGF-β type I receptor, namely, SB 431542, was investigated in our study. SB 431542 was used to treat TGF-β-treated IMR-90 cells; the expression of α-smooth muscle actin (α-SMA) was detected at the protein level by using an anti-α-SMA antibody, and at the gene level by reverse transcription-quantitative PCR. The effect of the inhibitor on cell proliferation was determined by a cell growth assay. The inhibitor was also administered into bleomycin-treated mice. Histopathological assessment and determination of total collagen levels were carried out to evaluate the severity of lung fibrosis in these mice. Our results demonstrated that treatment with SB 431542 inhibits TGF-β‑induced α-SMA expression in lung fibroblasts, at both the protein and the mRNA levels (P<0.05). However, the inhibitor did not significantly reduce lung fibroblast proliferation. In the bleomycin-induced pulmonary fibrosis mouse model, bleomycin treatment caused important morphological changes, accompanied by an increase in the collagen level of the lungs. Early treatment with SB 431542 prevented the manifestation of histopathological alterations, whereas delayed treatment significantly decreased the collagen level (P<0.05). These results suggest that inhibition of TGF-β signaling, via inhibition of the activin receptor-like kinase-5 (ALK-5) by SB 431542, may attenuate pulmonary fibrosis.
    Matched MeSH terms: Protein-Serine-Threonine Kinases/antagonists & inhibitors*; Protein-Serine-Threonine Kinases/metabolism
  11. Temporal proteomic profiling of Chlamydia trachomatis-infected HeLa-229 human cervical epithelial cells
    Tan GM, Lim HJ, Yeow TC, Movahed E, Looi CY, Gupta R, et al.
    Proteomics, 2016 05;16(9):1347-60.
    PMID: 27134121 DOI: 10.1002/pmic.201500219
    Chlamydia trachomatis is the leading causative agent of bacterial sexually transmitted infections worldwide which can lead to female pelvic inflammatory disease and infertility. A greater understanding of host response during chlamydial infection is essential to design intervention technique to reduce the increasing incidence rate of genital chlamydial infection. In this study, we investigated proteome changes in epithelial cells during C. trachomatis infection by using an isobaric tags for relative and absolute quantitation (iTRAQ) labeling technique coupled with a liquid chromatography-tandem mass spectrometry (LC-MS(3) ) analysis. C. trachomatis (serovar D, MOI 1)-infected HeLa-229 human cervical carcinoma epithelial cells (at 2, 4 and 8 h) showed profound modifications of proteome profile which involved 606 host proteins. MGST1, SUGP2 and ATXN10 were among the top in the list of the differentially upregulated protein. Through pathway analysis, we suggested the involvement of eukaryotic initiation factor 2 (eIF2) and mammalian target of rapamycin (mTOR) in host cells upon C. trachomatis infection. Network analysis underscored the participation of DNA repair mechanism during C. trachomatis infection. In summary, intense modifications of proteome profile in C. trachomatis-infected HeLa-229 cells indicate complex host-pathogen interactions at early phase of chlamydial infection.
    Matched MeSH terms: TOR Serine-Threonine Kinases/genetics*; TOR Serine-Threonine Kinases/metabolism
  12. Fulltext DAP Kinase-Related Apoptosis-Inducing Protein Kinase 2 (DRAK2) Is a Key Regulator and Molecular Marker in Chronic Lymphocytic Leukemia
    Szoltysek K, Ciardullo C, Zhou P, Walaszczyk A, Willmore E, Rand V, et al.
    Int J Mol Sci, 2020 Oct 16;21(20).
    PMID: 33081245 DOI: 10.3390/ijms21207663
    Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the Western World and it is characterized by a marked degree of clinical heterogeneity. An impaired balance between pro- and anti-apoptotic stimuli determines chemorefractoriness and outcome. The low proliferation rate of CLL cells indicates that one of the primary mechanisms involved in disease development may be an apoptotic failure. Here, we study the clinical and functional significance of DRAK2, a novel stress response kinase that plays a critical role in apoptosis, T-cell biology, and B-cell activation in CLL. We have analyzed CLL patient samples and showed that low expression levels of DRAK2 were significantly associated with unfavorable outcome in our CLL cohort. DRAK2 expression levels showed a positive correlation with the expression of DAPK1, and TGFBR1. Consistent with clinical data, the downregulation of DRAK2 in MEC-1 CLL cells strongly increased cell viability and proliferation. Further, our transcriptome data from MEC-1 cells highlighted MAPK, NF-κB, and Akt and as critical signaling hubs upon DRAK2 knockdown. Taken together, our results indicate DRAK2 as a novel marker of CLL survival that plays key regulatory roles in CLL prognosis.
    Matched MeSH terms: Protein-Serine-Threonine Kinases/genetics; Protein-Serine-Threonine Kinases/metabolism*
  13. Fulltext LMTK3 confers chemo-resistance in breast cancer
    Stebbing J, Shah K, Lit LC, Gagliano T, Ditsiou A, Wang T, et al.
    Oncogene, 2018 06;37(23):3113-3130.
    PMID: 29540829 DOI: 10.1038/s41388-018-0197-0
    Lemur tyrosine kinase 3 (LMTK3) is an oncogenic kinase that is involved in different types of cancer (breast, lung, gastric, colorectal) and biological processes including proliferation, invasion, migration, chromatin remodeling as well as innate and acquired endocrine resistance. However, the role of LMTK3 in response to cytotoxic chemotherapy has not been investigated thus far. Using both 2D and 3D tissue culture models, we found that overexpression of LMTK3 decreased the sensitivity of breast cancer cell lines to cytotoxic (doxorubicin) treatment. In a mouse model we showed that ectopic overexpression of LMTK3 decreases the efficacy of doxorubicin in reducing tumor growth. Interestingly, breast cancer cells overexpressing LMTK3 delayed the generation of double strand breaks (DSBs) after exposure to doxorubicin, as measured by the formation of γH2AX foci. This effect was at least partly mediated by decreased activity of ataxia-telangiectasia mutated kinase (ATM) as indicated by its reduced phosphorylation levels. In addition, our RNA-seq analyses showed that doxorubicin differentially regulated the expression of over 700 genes depending on LMTK3 protein expression levels. Furthermore, these genes were found to promote DNA repair, cell viability and tumorigenesis processes / pathways in LMTK3-overexpressing MCF7 cells. In human cancers, immunohistochemistry staining of LMTK3 in pre- and post-chemotherapy breast tumor pairs from four separate clinical cohorts revealed a significant increase of LMTK3 following both doxorubicin and docetaxel based chemotherapy. In aggregate, our findings show for the first time a contribution of LMTK3 in cytotoxic drug resistance in breast cancer.
    Matched MeSH terms: Protein-Serine-Threonine Kinases/genetics; Protein-Serine-Threonine Kinases/metabolism*
  14. Fulltext Curculigoside and polyphenol-rich ethyl acetate fraction of Molineria latifolia rhizome improved glucose uptake via potential mTOR/AKT activated GLUT4 translocation
    Ooi J, Azmi NH, Imam MU, Alitheen NB, Ismail M
    J Food Drug Anal, 2018 10;26(4):1253-1264.
    PMID: 30249324 DOI: 10.1016/j.jfda.2018.03.003
    Adipose tissue is one of the major organs responsible for rapid restoration of postprandial glucose fluxes. Being the major isoform of glucose transporter in adipose tissue, regulations of insulin-dependent GLUT4 trafficking have always been of research interest. The present study aimed to examine the molecular mechanisms underlying the efficacy of curculigoside and polyphenol-rich ethyl acetate fraction (EAF) of Molineria latifolia rhizome in triggering glucose uptake. We assessed the adipogenic potential and glucose uptake stimulatory activity of curculigoside and EAF by employing a murine 3T3-L1 adipocyte model. The transcriptional and translational expressions of selected intermediates in the insulin signalling pathway were evaluated. While curculigoside neither promoted adipogenesis nor activated peroxisome proliferator activated receptor gamma, treatment with polyphenol-rich EAF resulted otherwise. However, both treatments enhanced insulin-stimulated uptake of glucose. This was coupled with increased availability of GLUT4 at the plasma membrane of the differentiated adipocytes although the total GLUT4 protein level was unaffected. In addition, the treatment increased the phosphorylation of both AKT and mTOR, which have been reported to be associated with GLUT4 translocation. The present findings proposed that curculigoside and EAF increased glucose transport activity of 3T3-L1 adipocytes via GLUT4 translocation as a result of potential mTOR/AKT activation. The more potent efficacy observed with EAF suggested potential synergistic and multi-targeted action.
    Matched MeSH terms: TOR Serine-Threonine Kinases/genetics; TOR Serine-Threonine Kinases/metabolism*
  15. Rapamycin synergizes cisplatin sensitivity in basal-like breast cancer cells through up-regulation of p73
    Wong SW, Tiong KH, Kong WY, Yue YC, Chua CH, Lim JY, et al.
    Breast Cancer Res Treat, 2011 Jul;128(2):301-13.
    PMID: 20686837 DOI: 10.1007/s10549-010-1055-0
    Recent gene expression profiling studies have identified five breast cancer subtypes, of which the basal-like subtype is the most aggressive. Basal-like breast cancer poses serious clinical challenges as there are currently no targeted therapies available to treat it. Although there is increasing evidence that these tumors possess specific sensitivity to cisplatin, its success is often compromised due to its dose-limiting nephrotoxicity and the development of drug resistance. To overcome this limitation, our goal was to maximize the benefits associated with cisplatin therapy through drug combination strategies. Using a validated kinase inhibitor library, we showed that inhibition of the mTOR, TGFβRI, NFκB, PI3K/AKT, and MAPK pathways sensitized basal-like MDA-MB-468 cells to cisplatin treatment. Further analysis demonstrated that the combination of the mTOR inhibitor rapamycin and cisplatin generated significant drug synergism in basal-like MDA-MB-468, MDA-MB-231, and HCC1937 cells but not in luminal-like T47D or MCF-7 cells. We further showed that the synergistic effect of rapamycin plus cisplatin on basal-like breast cancer cells was mediated through the induction of p73. Depletion of endogenous p73 in basal-like cells abolished these synergistic effects. In conclusion, combination therapy with mTOR inhibitors and cisplatin may be a useful therapeutic strategy in the treatment of basal-like breast cancers.
    Matched MeSH terms: Protein-Serine-Threonine Kinases/genetics; Protein-Serine-Threonine Kinases/metabolism; TOR Serine-Threonine Kinases/genetics; TOR Serine-Threonine Kinases/metabolism
  16. Bisleuconothine A Induces Autophagosome Formation by Interfering with AKT-mTOR Signaling Pathway
    Wong CP, Seki A, Horiguchi K, Shoji T, Arai T, Nugroho AE, et al.
    J Nat Prod, 2015 Jul 24;78(7):1656-62.
    PMID: 26176165 DOI: 10.1021/acs.jnatprod.5b00258
    We have previously reported that bisleuconothine A (Bis-A), a novel bisindole alkaloid isolated from Leuconotis griffithii, showed cytostatic activity in several cell lines. In this report, the mechanism of Bis-A-induced cytostatic activity was investigated in detail using A549 cells. Bis-A did not cause apoptosis, as indicated by analysis of annexin V and propidium iodide staining. Expression of all tested apoptosis-related proteins was also unaffected by Bis-A treatment. Bis-A was found to increase LC3 lipidation in MCF7 cells as well as A549 cells, suggesting that Bis-A cytostatic activity may be due to induction of autophagy. Subsequent investigation via Western blotting and immunofluorescence staining indicated that Bis-A induced formation but prevented degradation of autophagosomes. Mechanistic studies showed that Bis-A down-regulated phosphorylation of protein kinase B (AKT) and its downstream kinase, PRAS40, which is an mTOR repressor. Moreover, phosphorylation of p70S6K, an mTOR-dependent kinase, was also down-regulated. Down-regulation of these kinases suggests that the increase in LC3 lipidation may be due to mTOR deactivation. Thus, the cytostatic activity shown by Bis-A may be attributed to its induction of autophagosome formation. The Bis-A-induced autophagosome formation was suggested to be caused by its interference with the AKT-mTOR signaling pathway.
    Matched MeSH terms: TOR Serine-Threonine Kinases/drug effects
  17. Fulltext DRD and GRIN2B polymorphisms and their association with the development of impulse control behaviour among Malaysian Parkinson's disease patients
    Zainal Abidin S, Tan EL, Chan SC, Jaafar A, Lee AX, Abd Hamid MH, et al.
    BMC Neurol, 2015;15:59.
    PMID: 25896831 DOI: 10.1186/s12883-015-0316-2
    Impulse control disorder (ICD) and behaviours (ICB) represent a group of behavioural disorders that have become increasingly recognised in Parkinson's disease (PD) patients who previously used dopaminergic medications, particularly dopamine agonists and levodopa. It has been suggested that these medications can lead to the development of ICB through the abnormal modulation of dopaminergic transmission and signalling in the mesocorticolimbic dopaminergic system. Several studies have reported an association between polymorphisms in the dopamine receptor (DRD) and N-methyl-D-aspartate 2B (GRIN2B) genes with the development of ICB in PD (PD-ICB) patients. Thus, this study aimed to investigate the association of selected polymorphisms within the DRD and GRIN2B genes with the development of ICB among PD patients using high resolution melt (HRM) analysis.
    Matched MeSH terms: Protein-Serine-Threonine Kinases/genetics
  18. Functional and structural characterisation of common cytochrome P450 2D6 allelic variants-roles of Pro34 and Thr107 in catalysis and inhibition
    Dong AN, Ahemad N, Pan Y, Palanisamy UD, Yiap BC, Ong CE
    Naunyn Schmiedebergs Arch Pharmacol, 2019 08;392(8):1015-1029.
    PMID: 31025144 DOI: 10.1007/s00210-019-01651-0
    One major source of inter-individual variability in drug pharmacokinetics is genetic polymorphism of the cytochrome P450 (CYP) genes. This study aimed to elucidate the enzyme kinetic and molecular basis for altered activity in three major alleles of CYP2D6, namely CYP2D6*2, CYP2D6*10 and CYP2D6*17. The E. coli-expressed allelic variants were examined using substrate (venlafaxine and 3-cyano-7-ethoxycoumarin[CEC]) and inhibitor (quinidine, fluoxetine, paroxetine, terbinafine) probes in enzyme assays as well as molecular docking. The kinetics data indicated that R296C and S486T mutations in CYP2D6*2 have caused enhanced ligand binding (enhanced intrinsic clearance for venlafaxine and reduced IC50 for quinidine, paroxetine and terbinafine), suggesting morphological changes within the active site cavity that favoured ligand docking and binding. Mutations in CYP2D6*10 and CYP2D6*17 tended to cause deleterious effect on catalysis, with reduced clearance for venlafaxine and CEC. Molecular docking indicated that P34S and T107I, the unique mutations in the alleles, have negatively impacted activity by affecting ligand access and binding due to alteration of the substrate access channel and active site morphology. IC50 values however were quite variable for quinidine, fluoxetine and terbinafine, and a general decrease in IC50 was observed for paroxetine, suggesting ligand-specific altered susceptibility to inhibition in the alleles. This study indicates that CYP2D6 allele selectivity for ligands was not solely governed by changes in the active site architecture induced by the mutations, but that the intrinsic properties of the substrates and inhibitors also played vital role.
    Matched MeSH terms: Threonine/genetics
  19. [Zn(phen)(O,N,O)(H2O)] and [Zn(phen)(O,N)(H2O)] with O,N,O is 2,6-dipicolinate and N,O is L-threoninate: synthesis, characterization, and biomedical properties
    Chin LF, Kong SM, Seng HL, Tiong YL, Neo KE, Maah MJ, et al.
    J Biol Inorg Chem, 2012 Oct;17(7):1093-105.
    PMID: 22825726 DOI: 10.1007/s00775-012-0923-y
    Two ternary Zn(II) complexes, with 1,10-phenanthroline (phen) as the main ligand and a carboxylate-containing ligand [dipicolinate (dipico) or L-threoninate (L-Thr)] as the subsidiary ligand, were prepared and characterized by elemental analysis, Fourier transform IR, UV, and fluorescence spectroscopy, X-ray diffraction, molar conductivity, and electrospray ionization mass spectrometry. X-ray structure analysis shows that both [Zn(phen)(dipico)(H(2)O)]·H(2)O (1) and [Zn(phen)(L-Thr)(H(2)O)Cl]·2H(2)O (2) have octahedral geometry about the Zn(II) atom. Both complexes can inhibit topoisomerase I, and have better anticancer activity than cisplatin against nasopharyngeal cancer cell lines, HK1 and HONE-1, with concentrations causing 50 % inhibition of cell proliferation (IC(50)) in the low micromolar range. Complex 2 has the highest therapeutic index for HK1. Both Zn(II) complexes can induce cell death by apoptosis. Changing the subsidiary ligand in the Zn(II) complexes affects the UV-fluorescence spectral properties of the coordinated phen ligand, the binding affinity for some DNA sequences, nucleobase sequence-selective binding, the phase at which cell cycle progression was arrested for treated cancer cells, and their therapeutic index.
    Matched MeSH terms: Threonine/chemistry*
  20. The Emerging Role of the Hippo Pathway in Lung Cancers: Clinical Implications
    Teoh SL, Das S
    Curr Drug Targets, 2017 Nov 30;18(16):1880-1892.
    PMID: 27628948 DOI: 10.2174/1389450117666160907153338
    BACKGROUND: The incidence of lung cancers has increased globally. Increased exposure to tobacco, passive smoking, less consumption of vegetables and fruits and occupational exposure to asbestos, arsenic and chromium are the main risk factors. The pathophysiology of lung cancer is complex and not well understood. Various microRNAs, genes and pathways are associated with lung cancers. The genes involved in lung cancers produce proteins involved in cell growth, differentiation, different cell cycles, apoptosis, immune modulation, tumor spread and progression. The Hippo pathway (also known as the Salvador-Warts-Hippo pathway) is the latest emerging concept in cancers. The Hippo pathway plays an important role in controlling the size of the tissue and organ by virtue of its action on cell proliferation and apoptosis.

    OBJECTIVE: In the present review, we highlight the mammalian Hippo pathway, role of its core members, its upstream regulators, downstream effectors and the resistance cases in lung cancers.

    RESULTS: Specific interaction of Mer with cell surface hyaluronan receptor CD44 is vital in cell contact inhibition, thereby activating Hippo pathway. Both transcription co-activators YAP and TAZ (also known as WWTR1, being homologs of Drosophila Yki) are important regulators of proliferation and apoptosis, and serve as major downstream effectors of the Hippo pathway. Mutation of NF2, the upstream regulator of Hippo pathway is linked to the cancers.

    CONCLUSION: Targeting YAP and TAZ may be important for future drug delivery and treatment.

    Matched MeSH terms: Protein-Serine-Threonine Kinases/metabolism
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