1.Tannic acid-induced apoptosis in FaDu hypopharyngeal squamous cell carcinoma
Loan Thi TA ; Trang Thi Kieu NGUYEN ; Hoon YOO
International Journal of Oral Biology 2019;44(2):43-49
Tannic acid (TA) is a water-soluble polyphenol compound found in various herbal plants. We investigated the chemopreventive effects of TA on FaDu hypopharyngeal squamous carcinoma cells. In an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, TA showed dose-dependent cytotoxicity with a half maximal inhibitory concentration (IC50) of 50 µM. Cell cycle analysis and immunofluorescence imaging demonstrated that under low-dose (25 µM) treatment, FaDu cells were arrested in G2/M phase, and as the dose of TA was increased, apoptosis was induced with the increase of cell population at sub-G1 phase. The expressions of various cyclins, including cyclin D1 and cyclin-dependent kinases (CDK-1 and CDK-2), were down-regulated at low doses of TA, whereas apoptotic effectors such as cleaved caspase 3, cleaved caspase 7, and poly (ADP-ribose) polymerase (PARP) were expressed in a dose-dependent manner in Western blotting. In addition, TA-induced apoptosis of FaDu cells might be mediated by the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase pathway, with the upregulation of p-AKT/p-PKB (phosphorylated protein kinase B) and p-ERK. Overall, our data support the hypothesis that TA is a potential candidate agent for the treatment of hypopharyngeal cancer.
Apoptosis
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Blotting, Western
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Carcinoma, Squamous Cell
;
Caspase 3
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Caspase 7
;
Cell Cycle
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Cyclin D1
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Cyclin-Dependent Kinases
;
Cyclins
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Epithelial Cells
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Fluorescent Antibody Technique
;
Hypopharyngeal Neoplasms
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Phosphotransferases
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Protein Kinases
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Tannins
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Up-Regulation
2.Antitumor effects of valdecoxib on hypopharyngeal squamous carcinoma cells
Nguyen Thi Kieu TRANG ; Hoon YOO
The Korean Journal of Physiology and Pharmacology 2022;26(6):439-446
The antitumoral effects of valdecoxib (Val), an United States Food and Drug Administration-approved anti-inflammatory drug that was withdrawn due to the side effects of increased risk of cardiovascular adverse events, were investigated in hypopharyngeal squamous cell carcinoma cells by performing a cell viability assay, transwell assay, immunofluorescence imaging, and Western blotting. Val markedly inhibited cell viability with an IC50 of 67.3 μM after 48 h of treatment, and also downregulated cell cycle proteins such as Cdks and their regulatory cyclin units. Cell migration and invasion were severely suppressed by inhibiting integrin α4/FAK expression. In addition, Val activated the cell cycle checkpoint CHK2 in response to excessive DNA damage, which led to the activation of caspase-3/9 and induced caspase-dependent apoptosis. Furthermore, the signaling cascades of the PI3K/AKT/ mTOR and mitogen-activated protein kinase pathways were significantly inhibited by Val treatment. Taken together, our results indicate that Val can be used for the treatment of hypopharyngeal squamous cell carcinoma.
3.Preparation and characterization of rutile phase TiO₂ nanoparticles and their cytocompatibility with oral cancer cells
Vu Phuong DONG ; Nguyen Thi Kieu TRANG ; Hoon YOO
International Journal of Oral Biology 2019;44(3):108-114
In the present study, rutile phase titanium dioxide nanoparticles (R-TiO₂ NPs) were prepared by hydrolysis of titanium tetrachloride in an aqueous solution followed by calcination at 900℃. The composition of R-TiO₂ NPs was determined by the analysis of X-ray diffraction data, and the characteristic features of R-TiO₂ NPs such as the surface functional group, particle size, shape, surface topography, and morphological behavior were analyzed by Fourier-transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, and zeta potential measurements. The average size of the prepared R-TiO₂ NPs was 76 nm, the surface area was 19 m²/g, zeta potential was −20.8 mV, and average hydrodynamic diameter in dimethyl sulfoxide (DMSO)–H₂O solution was 550 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological observations revealed that R-TiO₂ NPs were cytocompatible with oral cancer cells, with no inhibition of cell growth and proliferation. This suggests the efficacy of R-TiO₂ NPs for the aesthetic white pigmentation of teeth.
Dimethyl Sulfoxide
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Dynamic Light Scattering
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Hydrodynamics
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Hydrolysis
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Microscopy, Electron, Scanning
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Microscopy, Electron, Transmission
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Mouth Neoplasms
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Nanoparticles
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Particle Size
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Pigmentation
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Spectrometry, X-Ray Emission
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Spectrum Analysis
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Titanium
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Tooth
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X-Ray Diffraction
4.Probiotic potential of lactic acid bacteria isolated from Vietnamese sour-fermented fish product
Nguyen Pham Anh Thi ; Tran Huu Hau ; Nguyen Thi Nhu Huynh ; Huynh Van Liem ; Tran Kieu Dieu Thi ; Do Phuong Kieu ; Dang Huy Hoa ; Nguyen Thanh Nha ; Nguyen Pham Thien Trang ; Le Nguyen Khoi Nguyen ; Truong Thi Bich Van ; Do Tan Khang
Malaysian Journal of Microbiology 2022;18(2):222-226
Aims:
To isolate and characterize the lactic acid bacteria (LAB) strains from the “mam chua ca ro” (sour fermented fish) in the South of Vietnam and investigate their potential anti-bacterial properties.
Methodology and results:
Four LAB strains (MCR1, MCR2, MCR3 and MCR4) were isolated from the "mam chua ca ro" product and their anti-bacterial activity was determined using the spot assay and the paper disc diffusion method. The isolated LABs can inhibit Escherichia coli ATCC 25922, Staphyloccocus aureus ATCC 25923 and Vibrio parahaemolyticus BV016 and produce bacteriocin to control the growth of E. coli ATCC 25922 and S. aureus ATCC 25923, except V. parahaemolyticus. MCR2 was chosen to sequence 16S rRNA of Pediococcus acidilactic.
Conclusion, significance and impact of study
On the basis of their prominent anti-pathogenic bacteria activity, LAB strains isolated from Vietnamese sour-fermented fish products were verified as prospective probiotics.
Lactobacillales--isolation &
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purification
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Pediococcus acidilactici