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  1. Lee YT, Tan YJ, Oon CE
    Eur J Pharmacol, 2018 Sep 05;834:188-196.
    PMID: 30031797 DOI: 10.1016/j.ejphar.2018.07.034
    Molecular targeted therapies are revolutionized therapeutics which interfere with specific molecules to block cancer growth, progression, and metastasis. Many molecular targeted therapies approved by the Food and Drug Administration (FDA), have demonstrated remarkable clinical success in the treatment of a myriad of cancer types including breast, leukemia, colorectal, lung, and ovarian cancers. This review provides an update on the different types of molecular targeted therapies used in the treatment of cancer, focusing on the fundamentals of molecular targeted therapy, its mode of action in cancer treatment, as well as its advantages and limitations.
  2. Lee YT, Tan YJ, Oon CE
    Acta Pharm Sin B, 2023 Feb;13(2):478-497.
    PMID: 36873180 DOI: 10.1016/j.apsb.2022.09.010
    Cancer is the second leading cause of mortality globally which remains a continuing threat to human health today. Drug insensitivity and resistance are critical hurdles in cancer treatment; therefore, the development of new entities targeting malignant cells is considered a high priority. Targeted therapy is the cornerstone of precision medicine. The synthesis of benzimidazole has garnered the attention of medicinal chemists and biologists due to its remarkable medicinal and pharmacological properties. Benzimidazole has a heterocyclic pharmacophore, which is an essential scaffold in drug and pharmaceutical development. Multiple studies have demonstrated the bioactivities of benzimidazole and its derivatives as potential anticancer therapeutics, either through targeting specific molecules or non-gene-specific strategies. This review provides an update on the mechanism of actions of various benzimidazole derivatives and the structure‒activity relationship from conventional anticancer to precision healthcare and from bench to clinics.
  3. Lee YT, Tan YJ, Oon CE
    Biomedicines, 2023 Nov 15;11(11).
    PMID: 38002059 DOI: 10.3390/biomedicines11113059
    Growing evidence has highlighted that mitochondrial dysfunction contributes to drug-induced toxicities and leads to drug attrition and post-market withdrawals. The acetylation or deacetylation of mitochondrial proteins can affect mitochondrial functions as the cells adapt to various cellular stresses and other metabolic challenges. SIRTs act as critical deacetylases in modulating mitochondrial function in response to drug toxicity, oxidative stress, reactive oxygen species (ROS), and energy metabolism. We previously showed that a recently characterised SIRT inhibitor (BZD9L1) is non-toxic in rodents in a short-term toxicity evaluation. However, the impact of BZD9L1 on mitochondrial function is unknown. This work aims to determine the effects of BZD9L1 on mitochondrial function in human normal liver and kidney-derived cell lines using the Agilent Seahorse Cell Mito Stress Test to complement our short-term toxicity evaluations in vivo. The Mito Stress assay revealed that BZD9L1 could potentially trigger oxidative stress by inducing ROS, which promotes proton leak and reduces coupling efficiency in liver-derived THLE cells. However, the same was not observed in human kidney-derived HEK293 cells. Interestingly, BZD9L1 had no impact on SIRT3 protein expression in both cell lines but affected SOD2 and its acetylated form at 72 h in THLE cells, indicating that BZD9L1 exerted its effect through SIRT3 activity rather than protein expression. In contrast, BZD9L1 reduced SIRT1 protein expression and impacted the p53 protein differently in both cell lines. Although BZD9L1 did not affect the spare respiratory capacity in vitro, these findings call for further validation of mitochondrial function through assessment of other mitochondrial parameters to evaluate the safety of BZD9L1.
  4. Lee YT, Mohd Ismail NI, Wei LK
    PLoS One, 2021;16(1):e0245038.
    PMID: 33439913 DOI: 10.1371/journal.pone.0245038
    BACKGROUND: Ischemic stroke is one of the non-communicable diseases that contribute to the significant number of deaths worldwide. However, the relationship between microbiome and ischemic stroke remained unknown. Hence, the objective of this study was to perform systematic review on the relationship between human microbiome and ischemic stroke.

    METHODS: A systematic review on ischemic stroke was carried out for all articles obtained from databases until 22nd October 2020. Main findings were extracted from all the eligible studies.

    RESULTS: Eighteen eligible studies were included in the systematic review. These studies suggested that aging, inflammation, and different microbial compositions could contribute to ischemic stroke. Phyla Firmicutes and Bacteroidetes also appeared to manipulate post-stroke outcome. The important role of microbiota-derived short-chain fatty acids and trimethylamine N-oxide in ischemic stroke were also highlighted.

    CONCLUSIONS: This is the first systematic review that investigates the relationship between microbiome and ischemic stroke. Aging and inflammation contribute to differential microbial compositions and predispose individuals to ischemic stroke.

  5. Tan YJ, Lee YT, Mancera RL, Oon CE
    Life Sci, 2021 Nov 01;284:119747.
    PMID: 34171380 DOI: 10.1016/j.lfs.2021.119747
    BZD9L1 was previously described as a SIRT1/2 inhibitor with anti-cancer activities in colorectal cancer (CRC), either as a standalone chemotherapy or in combination with 5-fluorouracil. BZD9L1 was reported to induce apoptosis in CRC cells; however, the network of intracellular pathways and crosstalk between molecular players mediated by BZD9L1 is not fully understood. This study aimed to uncover the mechanisms involved in BZD9L1-mediated cytotoxicity based on previous and new findings for the prediction and identification of related pathways and key molecular players. BZD9L1-regulated candidate targets (RCTs) were identified using a range of molecular, cell-based and biochemical techniques on the HCT 116 cell line. BZD9L1 regulated major cancer pathways including Notch, p53, cell cycle, NFκB, Myc/MAX, and MAPK/ERK signalling pathways. BZD9L1 also induced reactive oxygen species (ROS), regulated apoptosis-related proteins, and altered cell polarity and adhesion profiles. In silico analyses revealed that most RCTs were interconnected, and were involved in the modulation of catalytic activity, metabolism and transcription regulation, response to cytokines, and apoptosis signalling pathways. These RCTs were implicated in p53-dependent apoptosis pathway. This study provides the first assessment of possible associations of molecular players underlying the cytotoxic activity of BZD9L1, and establishes the links between RCTs and apoptosis through the p53 pathway.
  6. Huan WY, Wan Azlan WA, Lee YT
    Asia Pac Psychiatry, 2023 Mar;15(1):e12524.
    PMID: 36575636 DOI: 10.1111/appy.12524
    Cotard's syndrome is a rare neuropsychiatric disorder characterized by marked nihilistic delusions. This report describes an Indonesian woman from a small town in Malaysia who was diagnosed with depression and Cotard's delusion. The diagnosis was confirmed after thorough history-taking, clinical examination, and relevant laboratory tests. Herein, we highlight the unique psychopathology of a possible Cotard's syndrome subtype and efficacy of pharmacological combination strategies, rather than monotherapy and electroconvulsive therapy, for its treatment.
  7. Chang CY, Lee YT, Liu KS, Wang YL, Tsao SM
    J Microbiol Immunol Infect, 2007 Jun;40(3):272-5.
    PMID: 17639170
    Chromobacterium violaceum is a facultative anaerobic, Gram-negative bacillus which inhabits stagnant water in tropical and subtropical regions. We describe the case of an 80-year-old female patient with C. violaceum bacteremia due to traumatic wound infected by contaminated water and soil. She had persistent fever, hypotension and neutrophilic leukocytosis on admission. Two sets of blood cultures yielded C. violaceum. The patient was successfully treated with levofloxacin. Since the first case from Malaysia in 1927, about 150 cases have been reported in the world literature. To our knowledge, six other cases have been reported previously from Taiwan, including two children and four adults. Of the total of seven patients from Taiwan, four had a fatal outcome within several days, while the three survivors were apparently free of vital organ involvement. Although human infections caused by C. violaceum are rare, clinicians should be aware of this potentially fatal infection as part of the differential diagnosis of sepsis associated with a history of exposure to stagnant water.
  8. Zhu JR, Tomlinson B, Ro YM, Sim KH, Lee YT, Sriratanasathavorn C
    Curr Med Res Opin, 2007 Dec;23(12):3055-68.
    PMID: 18196620
    BACKGROUND: Most studies investigating the benefits of statins have focused on North American and European populations. This study focuses on evaluating the lipid-lowering effects of rosuvastatin and atorvastatin in Asian patients.

    OBJECTIVES: The DIrect Statin COmparison of LDL-C Values: an Evaluation of Rosuvastatin therapY (DISCOVERY)-Asia study is one of nine independently powered studies assessing the efficacy of starting doses of statins in achieving target lipid levels in different countries worldwide. DISCOVERY-Asia was a 12-week, randomised, open-label, parallel-group study conducted in China, Hong Kong, Korea, Malaysia, Taiwan, and Thailand.

    RESULTS: A total of 1482 adults with primary hypercholesterolaemia and high cardiovascular risk (> 20%/10 years, type 2 diabetes, or a history of coronary heart disease) were randomised in a 2 : 1 ratio to receive rosuvastatin 10 mg once daily (o.d.) or atorvastatin 10 mg o.d. The percentage of patients achieving the 1998 European Joint Task Force low-density lipoprotein cholesterol (LDL-C) goal of < 3.0 mmol/L at 12 weeks was significantly higher in the rosuvastatin group (n = 950) compared with the atorvastatin group (n = 471) (79.5 vs. 69.4%, respectively; p < 0.0001). Similar results were observed for 1998 European goals for total cholesterol (TC), and the 2003 European goals for LDL-C and TC. LDL-C and TC levels were reduced significantly more with rosuvastatin compared with atorvastatin. Both drugs were well-tolerated and the incidence and type of adverse events were similar in each group.

    TRIALS REGISTRATION: The trial registry summary is available at http://www.clinicaltrials.gov/; ClinicalTrials.gov Identifier: NCT00241488

    CONCLUSIONS: This 12-week study showed that the starting dose of rosuvastatin 10 mg o.d. was significantly more effective than the starting dose of natorvastatin 10 mg o.d. at enabling patients with primary hypercholesterolaemia to achieve European goals for LDL-C and TC in a largely Asian population in real-life clinical practice. The safety profile of rosuvastatin 10 mg is similar to that of atorvastatin 10 mg in the Asian population studied here, and is consistent with the known safety profile of rosuvastatin in the white population.

  9. Tan YJ, Lee YT, Yeong KY, Petersen SH, Kono K, Tan SC, et al.
    Future Med Chem, 2018 Sep 01;10(17):2039-2057.
    PMID: 30066578 DOI: 10.4155/fmc-2018-0052
    AIM: This study aims to investigate the mode of action of a novel sirtuin inhibitor (BZD9L1) and its associated molecular pathways in colorectal cancer (CRC) cells.

    MATERIALS & METHODS: BZD9L1 was tested against metastatic CRC cell lines to evaluate cytotoxicity, cell cycle and apoptosis, senescence, apoptosis related genes and protein expressions, as well as effect against major cancer signaling pathways.

    RESULTS & CONCLUSION: BZD9L1 reduced the viability, cell migration and colony forming ability of both HCT 116 and HT-29 metastatic CRC cell lines through apoptosis. BZD9L1 regulated major cancer pathways differently in CRC with different mutation profiles. BZD9L1 exhibited anticancer activities as a cytotoxic drug in CRC and as a promising therapeutic strategy in CRC treatment.

  10. Lye HS, Lee YT, Ooi SY, Teh LK, Lim LN, Wei LK
    Front Biosci (Elite Ed), 2018 03 01;10:344-351.
    PMID: 29293462
    Aging, which affects most of the multi-cellular organisms, is due to a potentially complex set of mechanisms that collectively cause a time-dependent decline of physiological functions. Aging restrains longevity and leads to neurodegenerative diseases including dementia, Alzheimer's disease and lacunar stroke. Human microbiota is now considered to have a strong impact on the progression of aging. The impact of aging and the risk of neurodegenerative diseases can be reduced by using probiotics, or preferably by combining probiotics and prebiotics, also known as synbiotics, that can drastically modify the composition of gut microbiome.
  11. Wang QM, Cui H, Han SJ, Black-Schaffer R, Volz MS, Lee YT, et al.
    Neurosci Lett, 2014 May 21;569:6-11.
    PMID: 24631567 DOI: 10.1016/j.neulet.2014.03.011
    Noninvasive transcranial direct current stimulation (tDCS) and methylphenidate (MP) are associated with motor recovery after stroke. Based on the potentially complementary mechanisms of these interventions, we examined whether there is an interactive effect between MP and tDCS. In this preliminary study, we randomized subacute stroke subjects to receive tDCS alone, MP alone or combination of tDCS and MP. A blinded rater measured safety, hand function, and cortical excitability before and after treatment. None of the treatments caused any major or severe adverse effects or induced significant differences in cortical excitability. Analysis of variance of gain score, as measured by Purdue pegboard test, showed a significant between-group difference (F(2,6)=12.167, p=0.008). Post hoc analysis showed that the combination treatment effected greater Purdue pegboard gain scores than tDCS alone (p=0.017) or MP alone (p=0.01). Our preliminary data with nine subjects shows an interesting dissociation between motor function improvement and lack of motor corticospinal plasticity changes as indexed by transcranial magnetic stimulation in subacute stroke subjects.
  12. Tan YJ, Lee YT, Petersen SH, Kaur G, Kono K, Tan SC, et al.
    Ther Adv Med Oncol, 2019;11:1758835919878977.
    PMID: 31632470 DOI: 10.1177/1758835919878977
    Background: This study aims to investigate the combination effect of a novel sirtuin inhibitor (BZD9L1) with 5-fluorouracil (5-FU) and to determine its molecular mechanism of action in colorectal cancer (CRC).

    Methods: BZD9L1 and 5-FU either as single treatment or in combination were tested against CRC cells to evaluate synergism in cytotoxicity, senescence and formation of micronucleus, cell cycle and apoptosis, as well as the regulation of related molecular players. The effects of combined treatments at different doses on stress and apoptosis, migration, invasion and cell death mechanism were evaluated through two-dimensional and three-dimensional cultures. In vivo studies include investigation on the combination effects of BZD9L1 and 5-FU on colorectal tumour xenograft growth and an evaluation of tumour proliferation and apoptosis using immunohistochemistry.

    Results: Combination treatments exerted synergistic reduction on cell viability on HCT 116 cells but not on HT-29 cells. Combined treatments reduced survival, induced cell cycle arrest, apoptosis, senescence and micronucleation in HCT 116 cells through modulation of multiple responsible molecular players and apoptosis pathways, with no effect in epithelial mesenchymal transition (EMT). Combination treatments regulated SIRT1 and SIRT2 protein expression levels differently and changed SIRT2 protein localization. Combined treatment reduced growth, migration, invasion and viability of HCT 116 spheroids through apoptosis, when compared with the single treatment. In addition, combined treatment was found to reduce tumour growth in vivo through reduction of tumour proliferation and necrosis compared with the vehicle control group. This highlights the potential therapeutic effects of BZD9L1 and 5-FU towards CRC.

    Conclusion: This study may pave the way for use of BZD9L1 as an adjuvant to 5-FU in improving the therapeutic efficacy for the treatment of colorectal cancer.

  13. Oon CE, Subramaniam AV, Ooi LY, Yehya AHS, Lee YT, Kaur G, et al.
    World J Gastrointest Oncol, 2023 May 15;15(5):810-827.
    PMID: 37275453 DOI: 10.4251/wjgo.v15.i5.810
    BACKGROUND: The development of new vasculatures (angiogenesis) is indispensable in supplying oxygen and nutrients to fuel tumor growth. Epigenetic dysregulation in the tumor vasculature is critical to colorectal cancer (CRC) progression. Sirtuin (SIRT) enzymes are highly expressed in blood vessels. BZD9L1 benzimidazole analogue is a SIRT 1 and 2 inhibitor with reported anticancer activities in CRC. However, its role has yet to be explored in CRC tumor angiogenesis.

    AIM: To investigate the anti-angiogenic potential of BZD9L1 on endothelial cells (EC) in vitro, ex vivo and in HCT116 CRC xenograft in vivo models.

    METHODS: EA.hy926 EC were treated with half inhibitory concentration (IC50) (2.5 μM), IC50 (5.0 μM), and double IC50 (10.0 μM) of BZD9L1 and assessed for cell proliferation, adhesion and SIRT 1 and 2 protein expression. Next, 2.5 μM and 5.0 μM of BZD9L1 were employed in downstream in vitro assays, including cell cycle, cell death and sprouting in EC. The effect of BZD9L1 on cell adhesion molecules and SIRT 1 and 2 were assessed via real-time quantitative polymerase chain reaction (qPCR). The growth factors secreted by EC post-treatment were evaluated using the Quantibody Human Angiogenesis Array. Indirect co-culture with HCT116 CRC cells was performed to investigate the impact of growth factors modulated by BZD9L1-treated EC on CRC. The effect of BZD9L1 on sprouting impediment and vessel regression was determined using mouse choroids. HCT116 cells were also injected subcutaneously into nude mice and analyzed for the outcome of BZD9L1 on tumor necrosis, Ki67 protein expression indicative of proliferation, cluster of differentiation 31 (CD31) and CD34 EC markers, and SIRT 1 and 2 genes via hematoxylin and eosin, immunohistochemistry and qPCR, respectively.

    RESULTS: BZD9L1 impeded EC proliferation, adhesion, and spheroid sprouting through the downregulation of intercellular adhesion molecule 1, vascular endothelial cadherin, integrin-alpha V, SIRT1 and SIRT2 genes. The compound also arrested the cells at G1 phase and induced apoptosis in the EC. In mouse choroids, BZD9L1 inhibited sprouting and regressed sprouting vessels compared to the negative control. Compared to the negative control, the compound also reduced the protein levels of angiogenin, basic fibroblast growth factor, platelet-derived growth factor and placental growth factor, which then inhibited HCT116 CRC spheroid invasion in co-culture. In addition, a significant reduction in CRC tumor growth was noted alongside the downregulation of human SIRT1 (hSIRT1), hSIRT2, CD31, and CD34 EC markers and murine SIRT2 gene, while the murine SIRT1 gene remained unaffected, compared to vehicle control. Histology analyses revealed that BZD9L1 at low (50 mg/kg) and high (250 mg/kg) doses reduced Ki-67 protein expression, while BZD9L1 at the high dose diminished tumor necrosis compared to vehicle control.

    CONCLUSION: These results highlighted the anti-angiogenic potential of BZD9L1 to reduce CRC tumor progression. Furthermore, together with previous anticancer findings, this study provides valuable insights into the potential of BZD9L1 to co-target CRC tumor vasculatures and cancer cells via SIRT1 and/or SIRT2 down-regulation to improve the therapeutic outcome.

  14. Othman MY, Halepota HF, Le Linn Y, Lee YT, Chang KTE, Ahamed SH, et al.
    Pediatr Surg Int, 2021 Aug;37(8):1049-1059.
    PMID: 33963920 DOI: 10.1007/s00383-021-04915-0
    PURPOSE: Complete upfront resection of pediatric gastrointestinal lymphomas is recommended over biopsy whenever feasible, but either approach may have adverse sequelae. We sought to compare gastrointestinal and oncological outcomes of pediatric gastrointestinal lymphomas who underwent attempted upfront resection or biopsy of the presenting bowel mass.

    METHODS: We retrospectively reviewed charts of children with gastrointestinal lymphomas treated on LMB89 and LMB96 protocols from 2000 to 2019 who underwent upfront gastrointestinal surgery, and compared resection and biopsy groups.

    RESULTS: Of 33 children with abdominal lymphomas, 20 had upfront gastrointestinal surgery-10 each had resection or biopsy. Patients with attempted upfront resections had fewer postoperative gastrointestinal complications compared to biopsies (10% vs. 60%, p = 0.057), but longer time to chemotherapy initiation (median 11.5 vs. 4.5 days, p 

  15. Hussein HR, Chang CY, Zheng Y, Yang CY, Li LH, Lee YT, et al.
    Nanotechnology, 2024 Feb 09;35(17).
    PMID: 38262054 DOI: 10.1088/1361-6528/ad21a2
    Heparins are a family of sulfated linear negatively charged polysaccharides that have been widely used for their anticoagulant, antithrombotic, antitumor, anti-inflammatory, and antiviral properties. Additionally, it has been used for acute cerebral infarction relief as well as other pharmacological actions. However, heparin's self-aggregated macrocomplex may reduce blood circulation time and induce life-threatening thrombocytopenia (HIT) complicating the use of heparins. Nonetheless, the conjugation of heparin to immuno-stealth biomolecules may overcome these obstacles. An immunostealth recombinant viral capsid protein (VP28) was expressed and conjugated with heparin to form a novel nanoparticle (VP28-heparin). VP28-heparin was characterized and tested to determine its immunogenicity, anticoagulation properties, effects on total platelet count, and risk of inducing HIT in animal models. The synthesized VP28-heparin trimeric nanoparticle was non-immunogenic, possessed an average hydrodynamic size (8.81 ± 0.58 nm) optimal for the evasion renal filtration and reticuloendothelial system uptake (hence prolonging circulating half-life). Additionally, VP28-heparin did not induce mouse death or reduce blood platelet count when administered at a high dosein vivo(hence reducing HIT risks). The VP28-heparin nanoparticle also exhibited superior anticoagulation properties (2.2× higher prothrombin time) and comparable activated partial thromboplastin time, but longer anticoagulation period when compared to unfractionated heparin. The anticoagulative effects of the VP28-heparin can also be reversed using protamine sulfate. Thus, VP28-heparin may be an effective and safe heparin derivative for therapeutic use.
  16. Ge N, Brugge WR, Saxena P, Sahai A, Adler DG, Giovannini M, et al.
    Endosc Ultrasound, 2019 9 26;8(6):418-427.
    PMID: 31552915 DOI: 10.4103/eus.eus_61_19
    Background and Objectives: Currently, pancreatic cystic lesions (PCLs) are recognized with increasing frequency and have become a more common finding in clinical practice. EUS is challenging in the diagnosis of PCLs and evidence-based decisions are lacking in its application. This study aimed to develop strong recommendations for the use of EUS in the diagnosis of PCLs, based on the experience of experts in the field.

    Methods: A survey regarding the practice of EUS in the evaluation of PCLs was drafted by the committee member of the International Society of EUS Task Force (ISEUS-TF). It was disseminated to experts of EUS who were also members of the ISEUS-TF. In some cases, percentage agreement with some statements was calculated; in others, the options with the greatest numbers of responses were summarized.

    Results: Fifteen questions were extracted and disseminated among 60 experts for the survey. Fifty-three experts completed the survey within the specified time frame. The average volume of EUS cases at the experts' institutions is 988.5 cases per year.

    Conclusion: Despite the limitations of EUS alone in the morphologic diagnosis of PCLs, the results of the survey indicate that EUS-guided fine-needle aspiration is widely expected to become a more valuable method.

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