Int J Oral Biol.  2019 Jun;44(2):43-49. 10.11620/IJOB.2019.44.2.43.

Tannic acid-induced apoptosis in FaDu hypopharyngeal squamous cell carcinoma

• Ta LT
• Nguyen TT
• Yoo H

• KMID: 2452746
• DOI: http://doi.org/10.11620/IJOB.2019.44.2.43

Abstract

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.

Keyword

Apoptosis; Hypopharyngeal cancer; FaDu cells; Tannic acid

MeSH Terms

Apoptosis*
Blotting, Western
Carcinoma, Squamous Cell*
Caspase 3
Caspase 7
Cell Cycle
Cyclin D1
Cyclin-Dependent Kinases
Cyclins
Epithelial Cells*
Fluorescent Antibody Technique
Hypopharyngeal Neoplasms
Phosphotransferases
Protein Kinases
Tannins
Up-Regulation
Caspase 3
Caspase 7
Cyclin D1
Cyclin-Dependent Kinases
Cyclins
Phosphotransferases
Protein Kinases
Tannins