Quercetin induces tongue squamous cell carcinoma cell apoptosis via the JNK activation-regulated ERK/GSK-3α/β-mediated mitochondria-dependent apoptotic signaling pathway

Chun-Fa Huang; Shing-Hwa Liu; Tsung-Jung Ho; Kuan-I Lee; Kai-Min Fang; Wu-Chia Lo; Jui-Ming Liu; Chin-Ching Wu; Chin-Chuan Su

doi:10.3892/ol.2022.13198

Quercetin induces tongue squamous cell carcinoma cell apoptosis via the JNK activation-regulated ERK/GSK-3α/β-mediated mitochondria-dependent apoptotic signaling pathway

Oncol Lett. 2022 Mar;23(3):78. doi: 10.3892/ol.2022.13198. Epub 2022 Jan 11.

Authors

Chun-Fa Huang^{1

2}, Shing-Hwa Liu³, Tsung-Jung Ho^{4

5

6}, Kuan-I Lee⁷, Kai-Min Fang⁸, Wu-Chia Lo⁸, Jui-Ming Liu⁹, Chin-Ching Wu¹⁰, Chin-Chuan Su¹¹

Affiliations

¹ School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan, R.O.C.
² Department of Nursing, College of Medical and Health Science, Asia University, Taichung 413, Taiwan, R.O.C.
³ Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, R.O.C.
⁴ Integration Center of Traditional Chinese and Modern Medicine, Hualien Tzu Chi Hospital, Hualien 970, Taiwan, R.O.C.
⁵ Department of Chinese Medicine, Hualien Tzu Chi Hospital, Hualien 970, Taiwan, R.O.C.
⁶ School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien 970, Taiwan, R.O.C.
⁷ Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 427, Taiwan, R.O.C.
⁸ Department of Otolaryngology, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan, R.O.C.
⁹ Department of Urology, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan 330, Taiwan, R.O.C.
¹⁰ Department of Public Health, China Medical University, Taichung 404, Taiwan, R.O.C.
¹¹ Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua 500, Taiwan, R.O.C.

Abstract

Tongue squamous cell carcinoma (SCC) is a most common type of oral cancer. Due to its highly invasive nature and poor survival rate, the development of effective pharmacological therapeutic agents is urgently required. Quercetin (3,3',4',5,7-pentahydroxyflavone) is a polyphenolic flavonoid found in plants and is an active component of Chinese herbal medicine. The present study investigated the pharmacological effects and possible mechanisms of quercetin on apoptosis of the tongue SCC-derived SAS cell line. Following treatment with quercetin, cell viability was assessed via the MTT assay. Apoptotic and necrotic cells, mitochondrial transmembrane potential and caspase-3/7 activity were analyzed via flow cytometric analyses. A caspase-3 activity assay kit was used to detect the expression of caspase-3 activity. Western blot analysis was performed to examine the expression levels of proteins associated with the MAPKs, AMPKα, GSK3-α/β and caspase-related signaling pathways. The results revealed that quercetin induced morphological alterations and decreased the viability of SAS cells. Quercetin also increased apoptosis-related Annexin V-FITC fluorescence and caspase-3 activity, and induced mitochondria-dependent apoptotic signals, including a decrease in mitochondrial transmembrane potential and Bcl-2 protein expression, and an increase in cytosolic cytochrome c, Bax, Bak, cleaved caspase-3, cleaved caspase-7 and cleaved poly (ADP-ribose) polymerase protein expression. Furthermore, quercetin significantly increased the protein expression levels of phosphorylated (p)-ERK, p-JNK1/2 and p-GSK3-α/β, but not p-p38 or p-AMPKα in SAS cells. Pretreatment with the pharmacological JNK inhibitor SP600125 effectively reduced the quercetin-induced apoptosis-related signals, as well as p-ERK1/2 and p-GSK3-α/β protein expression. Both ERK1/2 and GSK3-α/β inhibitors, PD98059 and LiCl, respectively, could significantly prevent the quercetin-induced phosphorylation of ERK1/2 and GSK3-α/β, but not JNK activation. Taken together, these results suggested that quercetin may induce tongue SCC cell apoptosis via the JNK-activation-regulated ERK1/2 and GSK3-α/β-mediated mitochondria-dependent apoptotic signaling pathway.

Keywords: JNK/ERK/GSK3; apoptosis; mitochondria; quercetin; tongue squamous cell carcinoma.

Grants and funding

This study was supported by grants from the Changhua Christian Hospital, Changhua, Taiwan (grant no. 110-CCH-IRP-057), the Taichung Tzu chi Hospital, The Buddhist Tzuchi Medical Foundation (grant no. TTCRD 109-13), the Far Eastern Memorial Hospital, New Taipei City, Taiwan (grant no. FEMH-2013-C-028) and the China Medical University, Taichung, Taiwan (grant no. CMU109-S-64).