Displaying publications 1 - 20 of 55 in total

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  1. Sivaramakarthikeyan R, Iniyaval S, Saravanan V, Lim WM, Mai CW, Ramalingan C
    ACS Omega, 2020 May 05;5(17):10089-10098.
    PMID: 32391496 DOI: 10.1021/acsomega.0c00630
    Synthesis of a series of benzimidazole-ornamented pyrazoles, 6a-6j has been obtained from arylhydrazine and aralkyl ketones via a multistep synthetic strategy. Among them, a hybrid-possessing para-nitrophenyl moiety connected to a pyrazole scaffold (6a) exerted the highest anti-inflammatory activity, which is superior to the standard, diclofenac sodium. While executing the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, a hybrid-possessing para-bromophenyl unit integrated at the pyrazole structural motif (6i) exhibited the highest activity among the hybrids examined. Besides, evaluation of anticancer potency of the synthesized hybrids revealed that the one containing a para-fluorophenyl unit tethered at the pyrazole nucleus (6h) showed the highest activity against both the pancreatic cancer cells (SW1990 and AsPCl) investigated. Considerable binding affinity between B-cell lymphoma and the hybrid, 6h has been reflected while performing molecular docking studies (-8.65 kcal/mol). The outcomes of the investigation expose that these hybrids could be used as effective intermediates to construct more potent biological agents.
  2. Er JL, Goh PN, Lee CY, Tan YJ, Hii LW, Mai CW, et al.
    Apoptosis, 2018 Jun;23(5-6):343-355.
    PMID: 29740790 DOI: 10.1007/s10495-018-1459-6
    Pancreatic adenocarcinoma (PDAC) is a highly aggressive cancer with a high chance of recurrence, limited treatment options, and poor prognosis. A recent study has classified pancreatic cancers into four molecular subtypes: (1) squamous, (2) immunogenic, (3) pancreatic progenitor and (4) aberrantly differentiated endocrine exocrine. Among all the subtypes, the squamous subtype has the worst prognosis. This study aims to utilize large scale genomic datasets and computational systems biology to identify potential drugs targeting the squamous subtype of PDAC through combination therapy. Using the transcriptomic data available from the International Cancer Genome Consortium, Cancer Cell Line Encyclopedia and Connectivity Map, we identified 26 small molecules that could target the squamous subtype of PDAC. Among them include inhibitors targeting the SRC proto-oncogene (SRC) and the mitogen-activated protein kinase kinase 1/2 (MEK1/2). Further analyses demonstrated that the SRC inhibitors (dasatinib and PP2) and MEK1/2 inhibitor (pimasertib) synergized gemcitabine sensitivity specifically in the squamous subtype of PDAC cells (SW1990 and BxPC3), but not in the PDAC progenitor cells (AsPC1). Further analysis revealed that the synergistic effects are dependent on SRC or MEK1/2 activities, as overexpression of SRC or MEK1/2 completely abrogated the synergistic effects SRC inhibitors (dasatinib and PP2) and MEK1/2 inhibitor (pimasertib). In contrast, no significant toxicity was observed in the MRC5 human lung fibroblast and ARPE-19 human retinal pigment epithelial cells. Together, our findings suggest that combinations of SRC or MEK inhibitors with gemcitabine possess synergistic effects on the squamous subtype of PDAC cells and warrant further investigation.
  3. Hii LW, Lim SE, Leong CO, Chin SY, Tan NP, Lai KS, et al.
    BMC Complement Altern Med, 2019 Sep 14;19(1):257.
    PMID: 31521140 DOI: 10.1186/s12906-019-2663-9
    BACKGROUND: Clinacanthus nutans extracts have been consumed by the cancer patients with the hope that the extracts can kill cancers more effectively than conventional chemotherapies. Our previous study reported its anti-inflammatory effects were caused by inhibiting Toll-like Receptor-4 (TLR-4) activation. However, we are unsure of its anticancer effect, and its interaction with existing chemotherapy.

    METHODS: We investigated the anti-proliferative efficacy of polar leaf extracts (LP), non-polar leaf extracts (LN), polar stem extract (SP) and non-polar stem extracts (SN) in human breast, colorectal, lung, endometrial, nasopharyngeal, and pancreatic cancer cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assay. The most potent extracts was tested along with gemcitabine using our established drug combination analysis. The effect of the combinatory treatment in apoptosis were quantified using enzyme-linked immunosorbent assay (ELISA), Annexin V assay, antibody array and immunoblotting. Statistical significance was analysed using one-way analysis of variance (ANOVA) and post hoc Dunnett's test. A p-value of less than 0.05 (p may synergise with gemcitabine in the anti-tumor mechanism.

  4. Tiong JJL, Kho HL, Mai CW, Lau HL, Hasan SS
    BMC Med Educ, 2018 Jul 17;18(1):168.
    PMID: 30016945 DOI: 10.1186/s12909-018-1274-3
    BACKGROUND: This study was carried out to gauge the prevalence of academic dishonesty among academics in Malaysian universities. A direct comparison was made between academics of healthcare and non-healthcare courses to note the difference in the level of academic integrity between the two groups. In addition, the predisposing factors and implications of academic dishonesty, as well as the different measures perceived to be effective at curbing this problem were also investigated.

    METHODS: A cross-sectional study design with mixed qualitative and quantitative approaches was employed and data collection was carried out primarily using self-administered questionnaire.

    RESULTS: Approximately half (52.5%, n = 74) of all respondents (n = 141) reported having personally encountered at least one case of academic dishonesty involving their peers. The results also revealed the significantly higher prevalence of various forms of academic misconduct among healthcare academics compared to their non-healthcare counterparts. Although respondents were generally conscious of the negative implications associated with academic dishonesty, more than half of all cases of misconduct were not reported due to the indifferent attitude among academics. Low levels of self-discipline and integrity were found to be the major factors leading to academic misdeeds and respondents opined that university managements should be more proactive in addressing this issue.

    CONCLUSIONS: The outcome of this study should serve as a clarion call for all relevant stakeholders to start making immediate amends in order to improve the current state of affairs in academia.

  5. Yow HY, Tiong JJL, Mai CW, van der Werf E, Zainuddin ZM, Toh CC, et al.
    BMC Urol, 2021 Jun 29;21(1):95.
    PMID: 34187440 DOI: 10.1186/s12894-021-00860-1
    BACKGROUND: Nocturia is widely prevalent condition with detrimental effects on quality of life and general health. In Malaysia, there is a lack of up-to-date prevalence study on nocturia. This study aimed to investigate the prevalence of nocturia and awareness pertaining to nocturia among Malaysian adults.

    METHODS: A cross-sectional population-based study was conducted among Malaysian adults aged ≥ 18 years old. The data was collected by mixed mode self-administered questionnaire from May 2019 to September 2019. Nocturia was defined as one or more voids at night.

    RESULTS: There were a total of 4616 respondents with 74.5% of response rate. The overall prevalence of nocturia among Malaysian adults was found to be 57.3%. In multivariate analysis, respondents aged 31-40 (1.91 [1.52-2.40]) or > 60 years old (2.03 [1.48-2.71]), and those who presented with hypertension (2.84 [2.28-3.53]), diabetes mellitus (1.78 [1.42-2.25]), renal disease (3.58 [1.93-6.63]) or overactive bladder (1.61 [1.10-2.35]) were associated with higher prevalence of nocturia. A significantly lower disease prevalence (p 

  6. Chappel L, Wong LC, Leong CO, Mai CW, Meikle IT, Stanforth SP, et al.
    Bioorg Med Chem Lett, 2020 02 15;30(4):126910.
    PMID: 31882300 DOI: 10.1016/j.bmcl.2019.126910
    Six N-nitroaryl-2-amino-1,3-dichloropropane derivatives have been prepared and evaluated against 18 cancer cell lines and two non-cancerous cell lines. Analysis of cell viability data and IC50 values indicated that the presence of a trifluoromethyl group in the nitroaryl moiety is an important structural feature associated with the compounds' cytotoxicities.
  7. Hii LW, Chung FF, Soo JS, Tan BS, Mai CW, Leong CO
    Breast Cancer Res Treat, 2020 Feb;179(3):615-629.
    PMID: 31784862 DOI: 10.1007/s10549-019-05504-5
    PURPOSE: Breast cancer stem cells (CSCs) are a small subpopulation of cancer cells that have high capability for self-renewal, differentiation, and tumor initiation. CSCs are resistant to chemotherapy and radiotherapy, and are responsible for cancer recurrence and metastasis.

    METHODS: By utilizing a panel of breast cancer cells and mammospheres culture as cell-based screening platforms, we performed high-throughput chemical library screens to identify agents that are effective against breast CSCs and non-CSCs. The hit molecules were paired with conventional chemotherapy to evaluate the combinatorial treatment effects on breast CSCs and non-CSCs.

    RESULTS: We identified a total of 193 inhibitors that effectively targeting both breast CSCs and non-CSCs. We observed that histone deacetylase inhibitors (HDACi) synergized conventional chemotherapeutic agents (i.e., doxorubicin and cisplatin) in targeting breast CSCs and non-CSCs simultaneously. Further analyses revealed that quisinostat, a potent inhibitor for class I and II HDACs, potentiated doxorubicin-induced cytotoxicity in both breast CSCs and non-CSCs derived from the basal-like (MDA-MB-468 and HCC38), mesenchymal-like (MDA-MB-231), and luminal-like breast cancer (MCF-7). It was also observed that the basal-like breast CSCs and non-CSCs were more sensitive to the co-treatment of quisinostat with doxorubicin compared to that of the luminal-like breast cancer subtype.

    CONCLUSION: In conclusion, this study demonstrates the potential of HDACi as therapeutic options, either as monotherapy or in combination with chemotherapeutics against refractory breast cancer.

  8. Tan BS, Kang O, Mai CW, Tiong KH, Khoo AS, Pichika MR, et al.
    Cancer Lett, 2013 Aug 9;336(1):127-39.
    PMID: 23612072 DOI: 10.1016/j.canlet.2013.04.014
    6-Shogaol has been shown to possess many antitumor properties including inhibition of cancer cell growth, inhibition of cancer metastasis, induction of apoptosis in cancer cells and induction of cancer cell differentiation. Despite its prominent antitumor effects, the direct molecular target of 6-shogaol has remained elusive. To identify the direct targets of 6-shogaol, a comprehensive antitumor profile of 6-shogaol (NSC752389) was tested in the NCI-60 cell line in an in vitro screen. The results show that 6-shogaol is COMPARE negative suggesting that it functions via a mechanism of action distinct from existing classes of therapeutic agents. Further analysis using microarray gene profiling and Connectivity Map analysis showed that MCF-7 cells treated with 6-shogaol display gene expression signatures characteristic of peroxisome proliferator activated receptor γ (PPARγ) agonists, suggesting that 6-shogaol may activate the PPARγ signaling pathway for its antitumor effects. Indeed, treatment of MCF-7 and HT29 cells with 6-shogaol induced PPARγ transcriptional activity, suppressed NFκB activity, and induced apoptosis in breast and colon cancer cells in a PPARγ-dependent manner. Furthermore, 6-shogaol is capable of binding to PPARγ with a binding affinity comparable to 15-delta prostaglandin J2, a natural ligand for PPARγ. Together, our findings suggest that the antitumor effects of 6-shogaol are mediated through activation of PPARγ and imply that activation of PPARγ might be beneficial for breast and colon cancer treatment.
  9. Liew K, Yu GQS, Wei Pua LJ, Wong LZ, Tham SY, Hii LW, et al.
    Cancer Lett, 2021 Apr 28;504:81-90.
    PMID: 33587980 DOI: 10.1016/j.canlet.2021.02.006
    Despite recent in advances in the management of nasopharyngeal carcinoma (NPC), development of targeted therapy remains challenging particularly in patients with recurrent or metastatic disease. To search for clinically relevant targets for the treatment of NPC, we carried out parallel genome-wide functional screens to identified essential genes that are required for NPC cells proliferation and cisplatin resistance. We identified lymphocyte-specific protein tyrosine kinase (LCK) as a key vulnerability of both proliferation and cisplatin resistance. Depletion of endogenous LCK or treatment of cells with LCK inhibitor induced tumor-specific cell death and synergized cisplatin sensitivity in EBV-positive C666-1 and EBV-negative SUNE1 cells. Further analyses demonstrated that LCK is regulating the proliferation and cisplatin resistance through activation of signal transducer and activator of transcription 5 (STAT5). Taken together, our study provides a molecular basis for targeting LCK and STAT5 signaling as potential druggable targets for the management of NPC.
  10. Shyam S, Greenwood D, Mai CW, Tan SS, Mohd Yusof BN, Moy FM, et al.
    Cancers (Basel), 2021 Mar 02;13(5).
    PMID: 33801191 DOI: 10.3390/cancers13051036
    (1) Background: We studied the association of both conventional (BMI, waist and hip circumference and waist-hip ratio) and novel (UK clothing sizes) obesity indices with pancreatic cancer risk in the UK women's cohort study (UKWCS). (2) Methods: The UKWCS recruited 35,792 women from England, Wales and Scotland from 1995 to 1998. Cancer diagnosis and death information were obtained from the National Health Service (NHS) Central Register. Cox's proportional hazards regression was used to evaluate the association between baseline obesity indicators and pancreatic cancer risk. (3) Results: This analysis included 35,364 participants with a median follow-up of 19.3 years. During the 654,566 person-years follow up, there were 136 incident pancreatic cancer cases. After adjustments for age, smoking, education and physical activity, each centimetre increase in hip circumference (HR: 1.03, 95% CI: 1.01-1.05, p = 0.009) and each size increase in skirt size (HR: 1.12, 95% CI: 1.02-1.23, p = 0.041) at baseline increased pancreatic cancer risk. Baseline BMI became a significant predictor of pancreatic cancer risk (HR: 1.04, 95% CI: 1.00-1.08, p = 0.050) when latent pancreatic cancer cases were removed. Only baseline hip circumference was associated with pancreatic cancer risk (HR: 1.03, 95% CI: 1.00-1.05, p = 0.017) when participants with diabetes at baseline were excluded to control for reverse causality. (4) Conclusion: Hip circumference and skirt size were significant predictors of pancreatic cancer risk in the primary analysis. Thus, hip circumference is useful to assess body shape relationships. Additionally, standard skirt sizes offer an economical and objective alternative to conventional obesity indices for evaluating pancreatic cancer risk in women.
  11. Looi CK, Hii LW, Chung FF, Mai CW, Lim WM, Leong CO
    Cancers (Basel), 2021 Apr 08;13(8).
    PMID: 33918087 DOI: 10.3390/cancers13081786
    Epstein-Barr virus (EBV) infection is recognised as one of the causative agents in most nasopharyngeal carcinoma (NPC) cases. Expression of EBV viral antigens can induce host's antiviral immune response by activating the inflammasomes to produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and IL-18. These cytokines are known to be detrimental to a wide range of virus-infected cells, in which they can activate an inflammatory cell death program, called pyroptosis. However, aberrant inflammasome activation and production of its downstream cytokines lead to chronic inflammation that may contribute to various diseases, including NPC. In this review, we summarise the roles of inflammasomes during viral infection, how EBV evades inflammasome-mediated immune response, and progress into tumourigenesis. The contrasting roles of inflammasomes in cancer, as well as the current therapeutic approaches used in targeting inflammasomes, are also discussed in this review. While the inflammasomes appear to have dual roles in carcinogenesis, there are still many questions that remain unanswered. In particular, the exact molecular mechanism responsible for the regulation of the inflammasomes during carcinogenesis of EBV-associated NPC has not been explored thoroughly. Furthermore, the current practical application of inflammasome inhibitors is limited to specific tumour types, hence, further studies are warranted to discover the potential of targeting the inflammasomes for the treatment of NPC.
  12. Looi CK, Foong LC, Chung FF, Khoo AS, Loo EM, Leong CO, et al.
    Cell Biol Toxicol, 2023 Dec;39(6):2501-2526.
    PMID: 37755585 DOI: 10.1007/s10565-023-09830-9
    Nasopharyngeal carcinoma (NPC) is a distinct type of head and neck cancer that is highly associated with Epstein-Barr virus (EBV) infection. EBV acts as an epigenetic driver in NPC tumorigenesis, reprogramming the viral and host epigenomes to regulate viral latent gene expression, and creating an environment conducive to the malignant transformation of nasopharyngeal epithelial cells. Targeting epigenetic mechanisms in pre-clinical studies has been shown promise in eradicating tumours and overcoming immune resistance in some solid tumours. However, its efficacy in NPC remains inclusive due to the complex nature of this cancer. In this review, we provide an updated understanding of the roles of epigenetic factors in regulating EBV latent gene expression and promoting NPC progression. We also explore the crosstalk between epigenetic mechanisms and immune evasion in NPC. Particularly, we discuss the potential roles of DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors in reversing immune suppression and augmenting antitumour immunity. Furthermore, we highlight the advantages of combining epigenetic therapy and immune checkpoint inhibitor to reverse immune resistance and improve clinical outcomes. Epigenetic drugs have the potential to modulate both epigenetic mediators and immune factors involved in NPC. However, further research is needed to fully comprehend the diverse range of epigenetic modifications in NPC. A deeper understanding of the crosstalk between epigenetic mechanisms and immune evasion during NPC progression is crucial for the development of more effective treatments for this challenging disease.
  13. Hii LW, Chung FF, Mai CW, Yee ZY, Chan HH, Raja VJ, et al.
    Cells, 2020 04 04;9(4).
    PMID: 32260399 DOI: 10.3390/cells9040886
    Cancer stem cells (CSCs) represent rare tumor cell populations capable of self-renewal, differentiation, and tumor initiation and are highly resistant to chemotherapy and radiotherapy. Thus, therapeutic approaches that can effectively target CSCs and tumor cells could be the key to efficient tumor treatment. In this study, we explored the function of SPHK1 in breast CSCs and non-CSCs. We showed that RNAi-mediated knockdown of SPHK1 inhibited cell proliferation and induced apoptosis in both breast CSCs and non-CSCs, while ectopic expression of SPHK1 enhanced breast CSC survival and mammosphere forming efficiency. We identified STAT1 and IFN signaling as key regulatory targets of SPHK1 and demonstrated that an important mechanism by which SPHK1 promotes cancer cell survival is through the suppression of STAT1. We further demonstrated that SPHK1 inhibitors, FTY720 and PF543, synergized with doxorubicin in targeting both breast CSCs and non-CSCs. In conclusion, we provide important evidence that SPHK1 is a key regulator of cell survival and proliferation in breast CSCs and non-CSCs and is an attractive target for the design of future therapies.
  14. Yeong KY, Tan SC, Mai CW, Leong CO, Chung FF, Lee YK, et al.
    Chem Biol Drug Des, 2018 01;91(1):213-219.
    PMID: 28719017 DOI: 10.1111/cbdd.13072
    Both sirtuin and poly(ADP-ribose)polymerase (PARP) family of enzymes utilize NAD+ as co-substrate. Inhibitors of sirtuins and PARPs are important tools in drug discovery as they are reported to be linked to multiple diseases such as cancer. New potent sirtuin inhibitors (2,4,6-trisubstituted benzimidazole) were discovered from reported PARP inhibitor scaffold. Interestingly, the synthesized compounds have contrasting sirtuin and PARP-1 inhibitory activities. We showed that modification on benzimidazoles may alter their selectivity toward sirtuin or PARP-1 enzymes. This offers an opportunity for further discovery and development of new promising sirtuin inhibitors. Molecular docking studies were carried out to aid the rationalization of these observations. Preliminary antiproliferative studies of selected compounds against nasopharyngeal cancer cells also showed relatively promising results.
  15. Chung FF, Mai CW, Ng PY, Leong CO
    Curr Cancer Drug Targets, 2016;16(1):71-8.
    PMID: 26563883
    Cytochrome P450, family 2, subfamily W, polypeptide 1 (CYP2W1) is a newly identified monooxygenase enzyme that is expressed specifically in tumor tissues and during fetal life. Particularly, high expression of CYP2W1 was observed in up to 60% of colorectal cancers and its expression correlated with poor survival. CYP2W1 has been shown to metabolize various endogenous substrates including lysophospholipids and several procarcinogens, such as polycyclic aromatic hydrocarbon. The specific substrate for CYP2W1, however, is currently unknown. Due to its tumor-specific expression and its unique catalytic activities in colorectal cancers, CYP2W1 was deemed as an interesting target in colorectal cancer therapy. This review sought to summarize the current understanding of the CYP2W1 biology and biochemistry, its genetic polymorphisms and cancer risk, and its implication as a tumor-specific diagnostic and therapeutic target.
  16. Wu YS, Lee ZY, Chuah LH, Mai CW, Ngai SC
    Curr Cancer Drug Targets, 2019;19(2):82-100.
    PMID: 29714144 DOI: 10.2174/1568009618666180430130248
    Despite advances in the treatment regimen, the high incidence rate of breast cancer (BC) deaths is mostly caused by metastasis. Recently, the aberrant epigenetic modifications, which involve DNA methylation, histone modifications and microRNA (miRNA) regulations become attractive targets to treat metastatic breast cancer (MBC). In this review, the epigenetic alterations of DNA methylation, histone modifications and miRNA regulations in regulating MBC are discussed. The preclinical and clinical trials of epigenetic drugs such as the inhibitor of DNA methyltransferase (DNMTi) and the inhibitor of histone deacetylase (HDACi), as a single or combined regimen with other epigenetic drug or standard chemotherapy drug to treat MBCs are discussed. The combined regimen of epigenetic drugs or with standard chemotherapy drugs enhance the therapeutic effect against MBC. Evidences that epigenetic changes could have implications in diagnosis, prognosis and therapeutics for MBC are also presented. Several genes have been identified as potential epigenetic biomarkers for diagnosis and prognosis, as well as therapeutic targets for MBC. Endeavors in clinical trials of epigenetic drugs against MBC should be continued although limited success has been achieved. Future discovery of epigenetic drugs from natural resources would be an attractive natural treatment regimen for MBC. Further research is warranted in translating research into clinical practice with the ultimate goal of treating MBC by epigenetic therapy in the near future.
  17. Mai CW, Chung FF, Leong CO
    Curr Drug Targets, 2017;18(11):1259-1268.
    PMID: 27993111 DOI: 10.2174/1389450117666161216125344
    BACKGROUND: Recent reports indicate that the tumor microenvironment plays a pivotal role in cancer development and progression, leading to a paradigm shift in the way cancer is studied and targeted. In contrast to traditional approaches, where only tumor cells are targeted for the treatment, an emerging approach is to develop therapeutics which target the tumor microenvironment while complementing or enhancing current treatments. Legumain (LGMN) is a newly identified target which is highly expressed in the tumor microenvironment and in tumor cells, and holds potential both as a biomarker and as a therapeutic target.

    CONCLUSION: This review will be the first to summarize the expression of LGMN in common cancers, as well as its roles in tumorigenesis and metastasis. This review also discusses the current developments and future prospects of targeting LGMN through the development of DNA vaccines, azopeptides, small molecule inhibitors and LGMN activated prodrugs, highlighting the potential of LGMN as a target for cancer therapeutics.

  18. Murthy S, Hazli UHAM, Kong KW, Mai CW, Leong CO, Rahman NA, et al.
    Curr Org Synth, 2019;16(8):1166-1173.
    PMID: 31984923 DOI: 10.2174/1570179416666191003095253
    BACKGROUND: Sesamol is a widely used antioxidant for the food and pharmaceutical industries. The oxidation products of this compound may be accumulated in foods or ingested. Little is known about its effect on human health.

    OBJECTIVE: It is of great interest to identify the oxidation products of sesamol that may be beneficial to humans. This study was undertaken to identify the oxidation products of sesamol and investigate their antioxidant and cytotoxic activities.

    MATERIALS AND METHODS: Using the ferricyanide oxidation approach, four oxidation products of sesamol (2, 3, 20 & 21) have been identified. Structural elucidation of these compounds was established on the basis of their detailed NMR spectroscopic analysis, mass spectrometry and x-ray crystallography. Additionally, a formation mechanism of compound 20 was proposed based on high-resolution mass spectrometry-fragmentation method. The antioxidant activities of these compounds were determined by the DPPH, FRAP, and ABTS assays. The in vitro antiproliferative activity of these compounds was evaluated against a panel of human cancer cell lines as well as non-cancerous cells.

    RESULTS: Two oxidation products of sesamol were found to contain an unusual methylenedioxy ring-opening skeleton, as evidenced by spectroscopic and x-ray crystallographic data. Among all compounds, 20 displayed impressive antiproliferative activities against a panel of human cancer cell lines yet remained non-toxic to noncancerous cells. The antioxidant activities of compound 20 are significantly weaker than sesamol as determined by the DPPH, FRAP, and ABTS assays.

    CONCLUSION: The oxidation products of sesamol could be a valuable source of bioactive molecules. Compound 20 may be used as a potential lead molecule for cancer studies.

  19. Chong YS, Mai CW, Leong CO, Wong LC
    Cutan Ocul Toxicol, 2018 Mar;37(1):52-60.
    PMID: 28554225 DOI: 10.1080/15569527.2017.1335748
    PURPOSE: Dysfunction of the microRNA (miRNA)-processing enzyme DICER1 and Alu RNA accumulation are linked to the pathogenesis of age-related macular degeneration (AMD). This study determined the optimal dose of lutein (LUT) and zeaxanthin (ZEA) to protect human retinal pigment epithelium (RPE) cells against hydrogen peroxide (H2O2). The effect of the optimal dose of LUT and ZEA as DICER1 and Alu RNA modulators in cultured human RPE cells challenged with H2O2 was investigated.

    MATERIALS AND METHODS: ARPE-19 cells were pre-treated with LUT, ZEA, or both for 24 h before 200 μM H2O2 challenge. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. DICER1 and Alu RNA were quantified by western blotting and real-time polymerase chain reaction, respectively.

    RESULTS: H2O2 increased cell Alu RNA expression and decreased cell viability of ARPE-19, but had no significant impact on the DICER1 protein level. LUT, alone and in combination with ZEA pre-treatment, prior to H2O2 challenge significantly improved cell viability of ARPE-19 and reduced the level of Alu RNA compared to the negative control.

    CONCLUSIONS: These results support the use of LUT alone, and in combination with ZEA, in AMD prevention and treatment. This study is also the first to report LUT modulating effects on Alu RNA.

  20. Mai CW, Yaeghoobi M, Abd-Rahman N, Kang YB, Pichika MR
    Eur J Med Chem, 2014 Apr 22;77:378-87.
    PMID: 24675137 DOI: 10.1016/j.ejmech.2014.03.002
    In the present study, a series of 46 chalcones were synthesised and evaluated for antiproliferative activities against the human TRAIL-resistant breast (MCF-7, MDA-MB-231), cervical (HeLa), ovarian (Caov-3), lung (A549), liver (HepG2), colorectal (HT-29), nasopharyngeal (CNE-1), erythromyeloblastoid (K-562) and T-lymphoblastoid (CEM-SS) cancer cells. The chalcone 38 containing an amino (-NH2) group on ring A was the most potent and selective against cancer cells. The effects of the chalcone 38 on regulation of 43 apoptosis-related markers in HT-29 cells were determined. The results showed that 20 apoptotic markers (Bad, Bax, Bcl-2, Bcl-w, Bid, Bim, CD40, Fas, HSP27, IGF-1, IGFBP-4, IGFBP-5, Livin, p21, Survivin, sTNF-R2, TRAIL-R2, XIAP, caspase-3 and caspase-8) were either up regulated or down regulated.
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