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Tan M, Lim E, Koe X, Tay Y, Teah Y, Rusli N, Jamil M, Adenan M, Wahab H, Wischmeyer E, Wei H. In vitro safety assessments of mitragynine, an euphoric compound isolated from Kratom, a herb-based legal high. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.2095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Luntz M, Malatskey S, Tan M, Bar-Meir E, Ruimi D. Volume of Mastoid Pneumatization: Three-Dimensional Reconstruction with Ultrahigh-Resolution Computed Tomography. Ann Otol Rhinol Laryngol 2016; 110:486-90. [PMID: 11372935 DOI: 10.1177/000348940111000516] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The volume of the mastoid air cell system was measured in 69 patients with normal middle ears. All patients underwent axial ultrahigh-resolution computed tomography. Mastoid pneumatization was marked on each axial slice, and 3-dimensional reconstruction was performed. The volumes were measured with a volumetric algorithm. A polyethylene tubing phantom with a density similar to that of bone on computed tomography was devised. The polyethylene tubing was tied in a particular fashion so as to create interconnecting air spaces with a known volume. The phantom was scanned with the imaging parameters used for scanning the temporal bone. The air in the tubing was marked, and 3-dimensional reconstruction for the marked phantom air was performed. The volume of the interconnecting air spaces was measured and found to be identical to its known volume, thereby verifying the accuracy of the method used. The mean mastoid volume was 6.61 cm3. The smallest volume measured was 1.3 cm3, and the largest was 12.7 cm3. The importance of this technique lies in its high accuracy, ease of use, and ability to directly correlate mastoid size and clinical findings.
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Nag S, Tan M, Weinstein M. Parental Use of Sun Protection for Their Children – Does Skin Colour Matter? Paediatr Child Health 2016. [DOI: 10.1093/pch/21.supp5.e64b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
BACKGROUND: Excessive sun exposure during childhood years is a known risk factor for skin cancer. Fifty percent of lifetime UV exposure is acquired by age 19, highlighting the potential for prevention strategies in childhood. Existing guidelines from established pediatric, dermatology and cancer prevention societies are general and not specific to any skin phototype.
OBJECTIVES: Our primary objective was to compare the frequency of adequate sun protection used by parents of children with different skin phototypes. Our secondary objective was to explore parental attitudes and beliefs on sun safety for their children.
DESIGN/METHODS: Parents of children between the ages of 6 months to 6 years were systematically recruited. Parents received self-administered questionnaires containing 40-items that examine the amount of sun protection parents used on their children, as well as their attitudes and beliefs about sun safety. Parents were also requested to self-assess their child’s Fitzpatrick Phototype (FP), and based on this response, they were divided into two groups: “lighter-skinned” (FP I-III) and “darker-skinned” (FP IV-VI). Guidelines from the Canadian Dermatology Association (CDA) on sun safety were used to quantify adequate sun protection.
RESULTS: A total of 183 parents completed the questionnaires, and 150 eligible parents (the first 25 of each FP) were included in the study. Overall, only 17% of parents used adequate sun protection for their children. Parents of lighter-skinned children were significantly more likely to use adequate sun protection (OR=17.0). As their child got older, parents were also significantly less likely to use adequate sun protection for them (OR=0.64). A significantly larger portion of parents of lighter-skin children believe that sun exposure was harmful (OR=14.2) and perceived more value in sun protection (OR=14.2), whereas parents of darker-skin children were significantly more likely to believe that darker skin tones provided more sun protection (OR=4.1).
CONCLUSION: Our study suggests that parental sun protection efforts were overall low, but especially in parents of darker-skinned children. The identified underlying attitudes and beliefs can aid in the design and delivery of sun protection interventions in the future, to ensure sun safety for all children, especially in a multiracial population.
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Yang Y, Luo YY, Wu S, Tang YD, Rao XD, Xiong L, Tan M, Deng MZ, Liu H. Association between C677T and A1298C polymorphisms of the MTHFR gene and risk of male infertility: a meta-analysis. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr7631. [PMID: 27173242 DOI: 10.4238/gmr.15027631] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Published studies on the association between the C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene and male infertility risk are controversial. To obtain a more precise evaluation, we performed a meta-analysis based on published case-control studies. We conducted an electronic search of PubMed, EMBASE, the Cochrane Library, the Web of Science, and the China Knowledge Resource Integrated Database for papers on MTHFR gene C677T and A1298C polymorphisms and male infertility risk. Pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were used to assess the strength of association in homozygote, heterozygote, dominant, recessive, and additive models. Statistical heterogeneity, test of publication bias, and sensitivity analysis were carried out using the STATA software (Version 13.0). Overall, 21 studies of C677T (4505 cases and 4024 controls) and 13 studies of A1298C (2785 cases and 3094 controls) were included in this meta-analysis. For C677T, the homozygote comparison results were OR = 1.629, 95%CI (1.215- 2.184), and the recessive model results were OR = 1.462 (1.155- 1.850). For A1298C, the homozygote comparison results were OR = 1.289 (1.029-1.616), and the recessive model results were OR = 1.288 (1.034-1.604). In conclusion, the current meta-analysis showed that the MTHFR C677T polymorphism was associated with a significantly increased male infertility risk in the Asian and overall populations, but not in the Caucasian population, and there was a significant association between the A1298C polymorphism and male infertility risk in the Asian, Caucasian, and overall groups.
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Liu Y, Zhao R, Wang H, Luo Y, Wang X, Niu W, Zhou Y, Wen Q, Fan S, Li X, Xiong W, Ma J, Li X, Tan M, Li G, Zhou M. miR-141 is involved in BRD7-mediated cell proliferation and tumor formation through suppression of the PTEN/AKT pathway in nasopharyngeal carcinoma. Cell Death Dis 2016; 7:e2156. [PMID: 27010857 PMCID: PMC4823963 DOI: 10.1038/cddis.2016.64] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 02/24/2016] [Accepted: 02/24/2016] [Indexed: 12/21/2022]
Abstract
Bromodomain containing 7 (BRD7) was identified as a nuclear transcriptional regulatory factor. BRD7 functions as a tumor suppressor in multiple cancers, including nasopharyngeal carcinoma (NPC). In this study, we reported a novel mechanism of BRD7 in NPC progression. We demonstrated that the expression of miR-141 was remarkably increased in NPC tissues and was negatively correlated with the expression of BRD7 and the survival rate of NPC patients. Decreased expression levels of miR-141, including the primary, the precursor and the mature forms of miR-141, were found in BRD7-overexpressing HEK293, 5-8F and HNE1 cells compared the control cells, while there was no obvious effect on the expression levels of the two critical enzymes Drosha and Dicer. BRD7 can negatively regulate the promoter activity of miR-141, while no obvious binding site of BRD7 was found in the potential promoter region of miR-141. Moreover, ectopic expression of miR-141 can significantly promote cell proliferation and inhibit apoptosis in NPC, and rescuing the expression of miR-141 in BRD7-overexpressing NPC cells could partially reverse the tumor suppressive effect of BRD7 on cell proliferation and tumor growth in vitro and in vivo. Furthermore, the activation of the PTEN/AKT pathway mediated by the overexpression of BRD7 could be inhibited by rescuing the expression of miR-141, which accordingly results in the partial restoration of cell proliferation and tumor growth. Our findings demonstrate that the BRD7/miR-141/PTEN/AKT axis has critical roles in the progression of NPC and provide some promising targets for the diagnosis and treatment of NPC.
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Liu X, Xie H, Zheng H, Ren Y, Wang S, Tan M, Sun G, Wang B, Yu W, Ma X. In situgrafting MPEG on the surface of cell-loaded microcapsules for protein repellency. INT J POLYM MATER PO 2016. [DOI: 10.1080/00914037.2015.1074905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Dean-Colomb W, Tan M, Tang W, Ambs S, Yates C. Abstract P5-08-38: Low lactate dehydrogenase B expression correlates with decreased distant-metastasis free- and recurrence-free survival post-chemotherapy in basal-like breast cancer. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p5-08-38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background:
Metabolism is an important differentiating feature of cancer cells. Lactate dehydrogenases (LDH A/B) are metabolically important proteins involved in the critical inter-conversion of pyruvate to lactate and vice versa. Several reports suggest that LDHB levels are elevated in TNBC, compared to other breast cancer subtypes. However, we recently published that LDHB levels are low in TNBC cell lines and restoring LDHB results in decreased cell proliferation, oxidative phosphorylation, and reversal of EMT. Furthermore, in a small patient cohort, we have shown that although LDHB levels are higher in TNBC patients compared to non-TNBC patients, LDHB levels where consistently lower when compared to LDHA levels. Thus, we set out to determine if either "Hi" or "Low" LDHA and LDHB levels effect patient survival.
Methods:
Utilizing the publically available datasets contained within kmplot,which contains gene expression data and relapse free and overall survivall, we determined mean levels of LDHA and LDHB in breast cancer patients. To analyze the prognostic value, patient samples were split into two groups based upon expression above the mean (considered high expressors, "Hi") or below the mean (considered low expressors, "Low"). The two patient cohorts were compared by a Kaplan-Meier survival plot, and the hazard ratio with 95% confidence intervals and logrank P value calculated. Groups were further stratified based upon LDH levels prior to- and post-chemotherapy.
Results:
We found that in patients with luminal A and luminal B breast cancer, there were no significant changes in either LDHA (p=0.1) or LDHB (p=0.21) on distant metastasis-free (DMFS) or recurrence–free (RFS) survival. However, in the basal subtype (i.e. patients with ER negative and PR negative breast cancer), low levels of LDHB was significantly associated with poorer DMFS (p=0.025) (n=240) prior to chemotherapy and both DMSF (p=0.048) (n=176) and RFS (p=0.0082) (n=388) post-chemotherapy. Examining the mean expression values for each of these patient populations, we did not observe any significant changes in DMSF or RFS pre or post-chemotherapy, suggesting an intrinsic feature of basal-like patients with low LDHB expression to have a more aggressive phenotype. Interestingly, we did observe significance in RFS (n=581, p=0.0043) in patient with "Hi" LDHA expression pre-chemotherapy, however there was no significant associations of LDHA with RFS (p=0.19) (n=388) or DMSF (n=176, p=0.75) post-chemotherapy.
Conclusion:
These findings, coupled with our cell line data, showing overexpressing LDHB in TNBC cell lines results in decreased proliferation with increased mitochondrial damage and apoptosis, suggests that lower levels of LDHB expression is indeed associated with an aggressive breast cancer phenotype that undergoes EMT and the Warburg effect. This could contribute to the lack of pathological response after chemotherapy and thus increased risk for later metastasis. Additionally, given the very large number of patients examined within these independent datasets, these findings further suggest that low LDHB expression is a robust prognostic biomarker of clinical outcome in patients with a basal-like phenotype.
Citation Format: Dean-Colomb W, Tan M, Tang W, Ambs S, Yates C. Low lactate dehydrogenase B expression correlates with decreased distant-metastasis free- and recurrence-free survival post-chemotherapy in basal-like breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-38.
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Tan M, Rosa P, Le ST, Iqbal MA, Phillips ID, Harper P. Transmission performance improvement using random DFB laser based Raman amplification and bidirectional second-order pumping. OPTICS EXPRESS 2016; 24:2215-2221. [PMID: 26906797 DOI: 10.1364/oe.24.002215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate that a distributed Raman amplification scheme based on random distributed feedback (DFB) fiber laser enables bidirectional second-order Raman pumping without increasing relative intensity noise (RIN) of the signal. This extends the reach of 10 × 116 Gb/s DP-QPSK WDM transmission up to 7915 km, compared with conventional Raman amplification schemes. Moreover, this scheme gives the longest maximum transmission distance among all the Raman amplification schemes presented in this paper, whilst maintaining relatively uniform and symmetric signal power distribution, and is also adjustable in order to be highly compatible with different nonlinearity compensation techniques, including mid-link optical phase conjugation (OPC) and nonlinear Fourier transform (NFT).
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Haglund E, Gustavsson JS, Bengtsson J, Haglund Å, Larsson A, Fattal D, Sorin W, Tan M. Demonstration of post-growth wavelength setting of VCSELs using high-contrast gratings. OPTICS EXPRESS 2016; 24:1999-2005. [PMID: 26906776 DOI: 10.1364/oe.24.001999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate, for the first time, post-growth wavelength setting of electrically-injected vertical-cavity surface-emitting lasers (VCSELs) by using high-contrast gratings (HCGs) with different grating parameters. By fabricating HCGs with different duty cycle and period, the HCG reflection phase can be varied, in effect giving different optical cavity lengths for HCG-VCSELs with different grating parameters. This enables fabrication of monolithic multi-wavelength HCG-VCSEL arrays for wavelength-division multiplexing (WDM). The GaAs HCG is suspended in air by removing a sacrificial layer of InGaP. Electrically-injected 980-nm HCG-VCSELs with sub-mA threshold currents indicate high reflectivity from the GaAs HCGs. Lasing over a wavelength span of 15 nm was achieved, enabling a 4-channel WDM array with 5 nm channel spacing. A large wavelength setting span was enabled by an air-coupled cavity design and the use of only the HCG as top mirror.
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Wu H, Wang H, Liao H, Lv Y, Song X, Ma X, Tan M. Multifunctional Nanostructures for Tumor-Targeted Molecular Imaging and Photodynamic Therapy. Adv Healthc Mater 2016; 5:311-8. [PMID: 26626703 DOI: 10.1002/adhm.201500668] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 10/04/2015] [Indexed: 01/26/2023]
Abstract
A multifunctional ICG-FA-PPD nanostructure is constructed by a facile self-assembly method through the negatively charged indocyanine green (ICG)- and positively charged folic acid-modified PEI-PEG-gadoteric acid (FA-PPD). The resulting ICG-FA-PPD is not only able to be used for targeting tumors, magnetic resonance imaging (MRI), and near-infrared imaging, but, more importantly, it enables photodynamic therapy for tumor.
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Taguchi M, Schwalb N, Rong Y, Vanegas DC, Garland N, Tan M, Yamaguchi H, Claussen JC, McLamore ES. pulSED: pulsed sonoelectrodeposition of fractal nanoplatinum for enhancing amperometric biosensor performance. Analyst 2016; 141:3367-78. [DOI: 10.1039/c6an00069j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A technique for deposition of fractal nanometal as a transducer in electrochemical sensing is described. The effect(s) of duty cycle and deposition time were explored, and two sensors are demonstrated.
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Tan M, Jolly L, Murtaza M, Camonis J, Wood S. ISDN2014_0080: Usp9x regulates axon specification and growth. Int J Dev Neurosci 2015. [DOI: 10.1016/j.ijdevneu.2015.04.066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Liao H, Jiang C, Liu W, Vera JM, Seni OD, Demera K, Yu C, Tan M. Fluorescent Nanoparticles from Several Commercial Beverages: Their Properties and Potential Application for Bioimaging. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8527-8533. [PMID: 26372844 DOI: 10.1021/acs.jafc.5b04216] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The presence of nanoparticles in beverages has raised great concern in terms of potential impacts to consumer health. Herein, carbon dots in beverages kvass, pony malta, pilsner beer, Vivant Storm, and Profit were identified. They were shown to have a strong fluorescence under the excitation of ultraviolet light. The emission peaks shift to longer wavelengths accompanied by a remarkable fluorescence intensity decrease. The carbon dots are in the nanosized range and roughly spherical in appearance. Elemental analysis by X-ray photoelectron spectroscopy demonstrated the composition of Kvass carbon dots to be C 83.17%, O 13.83%, and N 3.00%. No cytotoxicity was found at concentrations up to 20 mg/mL for human tongue squamous carcinoma cells, and they can be directly applied in both carcinoma and onion epidermal cell imaging. This work represents the first report of the carbon dots present in beverages, providing valuable insights into these nanoparticles for future biological imaging.
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Wang B, Wang S, Wang Y, Lv Y, Wu H, Ma X, Tan M. Highly fluorescent carbon dots for visible sensing of doxorubicin release based on efficient nanosurface energy transfer. Biotechnol Lett 2015; 38:191-201. [DOI: 10.1007/s10529-015-1965-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 09/22/2015] [Indexed: 12/29/2022]
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Tan M, Li X, Wu H, Wang B, Wu J. N-doped carbon dots derived from bovine serum albumin and formic acid with one- and two-photon fluorescence for live cell nuclear imaging. Colloids Surf B Biointerfaces 2015; 136:141-9. [PMID: 26381697 DOI: 10.1016/j.colsurfb.2015.09.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 08/22/2015] [Accepted: 09/03/2015] [Indexed: 11/28/2022]
Abstract
Carbon dots with both one- and two-photon fluorescence have drawn great attention for biomedical imaging. Herein, nitrogen-doped carbon dots were facilely developed by one-pot hydrothermal method using bovine serum albumin and formic acid as carbon sources. They are highly water-soluble with strong fluorescence when excited with ultraviolet or near infrared light. The carbon dots have a diameter of ~8.32 nm and can emit strong two-photon induced fluorescence upon excitation at 750 nm with a femtosecond laser. X-ray photoelectron spectrometer analysis revealed that the carbon dots contained three components, C, N and O, corresponding to the peak at 285, 398 and 532 eV, respectively. The Fourier-transform infrared spectroscopy analysis revealed that there are carboxyl and carboxylic groups on the surface, which allowed further linking of functional molecules. pH stability study demonstrated that the carbon dots are able to be used in a wide range of pH values. The fluorescence mechanism is also discussed in this study. Importantly, these carbon dots are biocompatible and highly photostable, which can be directly applied for both one- and two-photon living cell imaging. After proper surface functionalization with TAT peptide, they can be used as fluorescent probes for live cell nuclear-targeted imaging.
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Wang Y, Wang B, Liao H, Song X, Wu H, Wang H, Shen H, Ma X, Tan M. Liposomal nanohybrid cerasomes for mitochondria-targeted drug delivery. J Mater Chem B 2015; 3:7291-7299. [PMID: 32262837 DOI: 10.1039/c5tb01197c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mitochondrial dysfunctions cause numerous human disorders and the development of mitochondria-targeted nanocarriers for drug delivery has aroused great attention. Herein, we report the synthesis of a liposomal nanohybrid cerasome modified with triphosphonium (TPP) for drug delivery to the mitochondrial matrix. The cerasomes were observed to possess an average size of about 38 nm in diameter, and the theoretical simulation of GBEMP mapping demonstrated that the amphiphilic organotrialkoxysilanes were stable as a bilayer equilibrium conformation after self-assembly. The cerasomes showed good stability, excellent biocompatibility and sustainable drug release behavior. Moreover, the TPP-targeted cerasomes resulted in greater drug accumulation in mitochondria, thus leading to a greater antitumor effect as compared to non-targeted cerasomes by using doxorubicin as a modal drug. The specific accumulation of TPP-targeted cerasomes within mitochondria was also confirmed by using JC-1 as the fluorescent probe to analyze the mitochondrial transmembrane potential change.
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Chung VY, Tan M, Tan TZ, Kuay KT, Ye J, Thiery JP, Huang RY. Abstract AS03: Epithelial-mesenchymal transition driven by transcriptional feedback loops contributes to intertumoral molecular heterogeneity in the metastasis and relapse of epithelial ovarian cancer. Clin Cancer Res 2015. [DOI: 10.1158/1557-3265.ovcasymp14-as03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Epithelial ovarian cancer (EOC) is highly heterogeneous with five molecular subgroups, Epi-A, Epi-B, Mes, Stem-A and Stem-B, being identified. The mechanisms behind the clonal evolution and intertumoral molecular heterogeneity are not fully elucidated. Previously, we performed EOC profiling meta-analysis to identify epithelial-mesenchymal transition (EMT) as the crucial mechanism for molecular heterogeneity. Transcription factors SNAI1, SNAI2, ZEB1, ZEB1, TWIST1, and GRHL2 were identified as crucial regulators for the Mes subtype which has undergone EMT. Here, we utilized three in-vitro EOC cell lines, PEO1, OVCA420, and OVCA429, to model the EMT-driven clonal evolution by manipulating the expression levels of these EMT transcriptional regulators. We analysed the molecular subtypes of matched primary tumor versus peritoneal metastases. Six out of 11 pairs showed concordant molecular subtypes. We also analysed a dataset of matched primary tumor versus omental metastases. Four out of 9 pairs showed concordant molecular subtypes. Among the 10 pairs showing a shift of molecular subtypes, 5 out of 5 omental metastases were designated as Mes. The variation in the evolution of molecular heterogeneity can be explained by the differences in the EMT transcriptional cross-regulation of the in-vitro models. Manipulating EMT regulators in PEO1 did not induce any transcriptional cross-regulation with no molecular subtype switching observed. However, manipulating EMT regulators in OVCA420 and OVCA429 caused hierarchical transcriptional control and feedback loop regulation, respectively. The OVCA429 model showed molecular subtype switch from Epi-A to Mes. In conclusion, the heterogeneity caused by EMT-driven clonal evolution is the consequence of transcriptional feedback loops of EMT regulators.
Citation Format: Chung VY, Tan M, Tan TZ, Kuay KT, Ye J, Thiery JP & Huang RY. Epithelial-mesenchymal transition driven by transcriptional feedback loops contributes to intertumoral molecular heterogeneity in the metastasis and relapse of epithelial ovarian cancer [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS03.
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Giaccone G, Bazhenova LA, Nemunaitis J, Tan M, Juhász E, Ramlau R, van den Heuvel MM, Lal R, Kloecker GH, Eaton KD, Chu Q, Dunlop DJ, Jain M, Garon EB, Davis CS, Carrier E, Moses SC, Shawler DL, Fakhrai H. A phase III study of belagenpumatucel-L, an allogeneic tumour cell vaccine, as maintenance therapy for non-small cell lung cancer. Eur J Cancer 2015; 51:2321-9. [PMID: 26283035 DOI: 10.1016/j.ejca.2015.07.035] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 07/12/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Treatment options after first-line chemotherapy are limited in non-small cell lung cancer (NSCLC). Belagenpumatucel-L is a therapeutic vaccine comprised of 4 transforming growth factor (TGF)-β2-antisense gene-modified, irradiated, allogeneic NSCLC cell lines that may be useful for maintenance after initial treatment. METHODS Stage III/IV NSCLC patients who did not progress after platinum-based chemotherapy were randomised 1:1 to receive maintenance belagenpumatucel-L or placebo. Patients were eligible for randomisation between one and four months from the end of induction chemotherapy. The primary endpoint was overall survival. RESULTS This phase III trial enrolled 270 patients in the belagenpumatucel-L arm and 262 in the control arm. Belagenpumatucel-L was well tolerated with no serious safety concerns. There was no difference in survival between the arms (median survival 20.3 versus 17.8months with belagenpumatucel-L versus placebo, respectively; hazard ratio (HR) 0.94, p=0.594). There were also no differences in progression-free survival (4.3months versus 4.0 for belagenpumatucel-L vs placebo, respectively; HR 0.99, p=0.947). A prespecified Cox regression analysis demonstrated that the time elapsed between randomisation and the end of induction chemotherapy had a significant impact on survival (p=0.002) and that prior radiation was a positive prognostic factor (median survival 28.4months with belagenpumatucel-L versus 16.0months with placebo; HR 0.61, p=0.032). CONCLUSIONS Although the overall trial did not meet its survival endpoint, improved survival for belagenpumatucel-L is suggested in patients who were randomised within 12weeks of completion of chemotherapy and in those who had received prior radiation. Further studies of belagenpumatucel-L in NSCLC are warranted.
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Shen Z, Wu H, Yang S, Ma X, Li Z, Tan M, Wu A. A novel Trojan-horse targeting strategy to reduce the non-specific uptake of nanocarriers by non-cancerous cells. Biomaterials 2015; 70:1-11. [PMID: 26295434 DOI: 10.1016/j.biomaterials.2015.08.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 08/09/2015] [Indexed: 12/22/2022]
Abstract
One big challenge with active targeting of nanocarriers is non-specific binding between targeting molecules and non-target moieties expressed on non-cancerous cells, which leads to non-specific uptake of nanocarriers by non-cancerous cells. Here, we propose a novel Trojan-horse targeting strategy to hide or expose the targeting molecules of nanocarriers on-demand. The non-specific uptake by non-cancerous cells can be reduced because the targeting molecules are hidden in hydrophilic polymers. The nanocarriers are still actively targetable to cancer cells because the targeting molecules can be exposed on-demand at tumor regions. Typically, Fe3O4 nanocrystals (FN) as magnetic resonance imaging (MRI) contrast agents were encapsulated into albumin nanoparticles (AN), and then folic acid (FA) and pH-sensitive polymers (PP) were grafted onto the surface of AN-FN to construct PP-FA-AN-FN nanoparticles. Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), transmission electron microscope (TEM) and gel permeation chromatography (GPC) results confirm successful construction of PP-FA-AN-FN. According to difference of nanoparticle-cellular uptake between pH 7.4 and 5.5, the weight ratio of conjugated PP to nanoparticle FA-AN-FN (i.e. graft density) and the molecular weight of PP (i.e. graft length) are optimized to be 1.32 and 5.7 kDa, respectively. In vitro studies confirm that the PP can hide ligand FA to prevent it from binding to cells with FRα at pH 7.4 and shrink to expose FA at pH 5.5. In vivo studies demonstrate that our Trojan-horse targeting strategy can reduce the non-specific uptake of the PP-FA-AN-FN by non-cancerous cells. Therefore, our PP-FA-AN-FN might be used as an accurately targeted MRI contrast agent.
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Song X, Wu H, Li S, Wang Y, Ma X, Tan M. Ultrasmall Chitosan-Genipin Nanocarriers Fabricated from Reverse Microemulsion Process for Tumor Photothermal Therapy in Mice. Biomacromolecules 2015; 16:2080-90. [PMID: 26075349 DOI: 10.1021/acs.biomac.5b00511] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nanocarriers play an important role in improving the photo- and thermal-stability of photosensitizers to gain better pharmacokinetics behavior in tumor photothermal therapy. Herein, PEGylated chitosan (CG-PEG; PEG: polyethylene glycol) nanoparticles with ultrasmall size (∼5 nm) were prepared through a water-in-oil reverse microemulsion method using genipin as a cross-linker. Particle size and zeta-potential can be tuned by varying the molar ratio between chitosan amino groups and genipin. CG-PEG-ICG (ICG: indocyanine green) nanoparticles were fabricated by adding ICG to CG-PEG aqueous solution through a self-assembly method via electrostatic interaction. The resultant CG-PEG-ICG nanoparticles exhibited improved photo- and thermal-stability, good biocompatibility, and low toxicity. When irradiated with a laser, the cells incubated with CG-PEG-ICG nanoparticles showed very low cell viability (15%), indicating the CG-PEG-ICG nanoparticles possess high in vitro photothermal toxicity. Moreover, the CG-PEG nanocarriers can significantly alter the biodistribution and prolong the retention time of ICG in the mice body after intravenous injection. In vivo photothermal study of tumors injected with CG-PEG-ICG nanoparticles containing ICG at a concentration greater than 100 μg·mL(-1) (100 μL) induced irreversible tissue damage. The growth of U87 tumors was dramatically inhibited by CG-PEG-ICG nanoparticles, demonstrating that the CG-PEG nanoparticles may act as potential ICG nanocarriers for effective in vivo tumor photothermal therapy.
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271
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Tan M, Quintal L. Pembrolizumab: a novel antiprogrammed death 1 (PD-1) monoclonal antibody for treatment of metastatic melanoma. J Clin Pharm Ther 2015; 40:504-507. [DOI: 10.1111/jcpt.12304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/18/2015] [Indexed: 01/01/2023]
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272
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Tan M, Nitz J, Boughen J, Fu S. Centre of gravity position in bipedal steady-stance is associated with performance of timed up and go but not functional reach. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.1459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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273
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Tan M, Tang C, Zhang Y, Cheng Y, Cai L, Chen X, Gao Y, Deng Y, Pan M. SIRT1/PGC-1α signaling protects hepatocytes against mitochondrial oxidative stress induced by bile acids. Free Radic Res 2015; 49:935-45. [PMID: 25789761 DOI: 10.3109/10715762.2015.1016020] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Oxidative stress and mitochondrial dysfunction are hypothesized to contribute to the pathogenesis of chronic cholestatic liver diseases. Silent information regulator 1 (SIRT1) attenuates oxidative stress and improves mitochondrial biogenesis in numerous mitochondrial-related diseases; however, a functional role for SIRT1 in chronic liver cholestasis, characterized by increased levels of toxic bile acids, remains unknown. We show decrease in SIRT1 levels and its activity and impairment of mitochondrial biogenesis in the liver of patients with extrahepatic cholestasis. Moreover, we found that glycochenodeoxycholic acid (GCDCA) stimulated cytotoxicity, disrupted the mitochondrial membrane potential, increased reactive oxygen species production, and decreased mitochondrial mass and mitochondrial DNA content in L02 cells. Consistent with this finding, GCDCA was found to decrease SIRT1 protein expression and activity, thus promoting the deacetylation of peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC-1α), a key enzyme involved in mitochondrial biogenesis and function. Conversely, GCDCA-induced mitochondrial injury was efficiently attenuated by SIRT1 overexpression. In summary, these findings indicate that the loss of SIRT1 may play a crucial role in the pathogenesis of liver damage observed in patients with extrahepatic cholestasis. The findings also indicate that genetic supplementation of SIRT1 can ameliorate GCDCA-induced hepatotoxicity through the activation of PGC-1α-dependent mitochondrial biogenesis.
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274
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Zhang J, Lv Y, Wang B, Zhao S, Tan M, Lv G, Ma X. Influence of microemulsion-mucin interaction on the fate of microemulsions diffusing through pig gastric mucin solutions. Mol Pharm 2015; 12:695-705. [PMID: 25608210 DOI: 10.1021/mp500475y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mucus layer, a selective diffusion barrier, has an important effect on the fate of drug delivery systems in the gastrointestinal tract. To study the fate of microemulsions in the mucus layer, four microemulsion formulations with different particle sizes and lipid compositions were prepared. The microemulsion-mucin interaction was demonstrated by the fluorescence resonance energy transfer (FRET) method. Moreover, the microemulsions were observed aggregated into micron-sized emulsions by laser confocal microscopy. We concluded the microemulsion-mucin interaction not only led to microemulsions closely adhered to mucins but also destroyed the structure of microemulsions. At last, the diffusion of blank microemulsions and microemulsion-carried drugs (resveratrol and hymecromone) through mucin solutions was determined by the fluorescence recovery after photobleaching (FRAP) method and the Franz diffusion cell method. The results demonstrated the diffusion of microemulsions was significantly hindered by mucin solutions. The particle size of microemulsions had a negligible effect on the diffusion coefficients. However, the type of lipid played an important role, which could form hydrophobic interactions with mucins. Interestingly, microemulsion-carried drugs with different core/shell locations seemed to suffer different fates in the mucin solutions. The drug incorporated in the oil core of microemulsions, resveratrol, was transported through the mucus layer by the carriers, while the drug incorporated in the surfactant shell of microemulsions, hymecromone, was separated from the carriers and diffused toward the epithelium in the form of free molecules.
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Tan M, Uppal S. The use of smartphones for intra-operative photography - how we do it. Clin Otolaryngol 2015; 39:130-1. [PMID: 24841058 DOI: 10.1111/coa.12227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2014] [Indexed: 11/30/2022]
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