Plumbagin suppresses epithelial to mesenchymal transition and stemness via inhibiting Nrf2-mediated signaling pathway in human tongue squamous cell carcinoma cells.
Tongue squamous cell carcinoma (TSCC) is the most common malignancy in oral and maxillofacial tumors with highly metastatic characteristics. Plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone; PLB), a natural naphthoquinone derived from the roots of Plumbaginaceae plants, exhibits various bioactivities, including anticancer effects. However, the potential molecular targets and underlying mechanisms of PLB in the treatment of TSCC remain elusive. This study employed stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomic approach to investigate the molecular interactome of PLB in human TSCC cell line SCC25 and elucidate the molecular mechanisms. The proteomic data indicated that PLB inhibited cell proliferation, activated death receptor-mediated apoptotic pathway, remodeled epithelial adherens junctions pathway, and manipulated nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated oxidative stress response signaling pathway in SCC25 cells with the involvement of a number of key functional proteins. Furthermore, we verified these protein targets using Western blotting assay. The verification results showed that PLB markedly induced cell cycle arrest at G2/M phase and extrinsic apoptosis, and inhibited epithelial to mesenchymal transition (EMT) and stemness in SCC25 cells. Of note, N-acetyl-l-cysteine (NAC) and l-glutathione (GSH) abolished the effects of PLB on cell cycle arrest, apoptosis induction, EMT inhibition, and stemness attenuation in SCC25 cells. Importantly, PLB suppressed the translocation of Nrf2 from cytosol to nucleus, resulting in an inhibition in the expression of downstream targets. Taken together, these results suggest that PLB may act as a promising anticancer compound via inhibiting Nrf2-mediated oxidative stress signaling pathway in SCC25 cells. This study provides a clue to fully identify the molecular targets and decipher the underlying mechanisms of PLB in the treatment of TSCC.
Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China.
Shu-Ting
ST
Pan
Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA.
Yiru
Y
Qin
Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA ; Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, Guizhou, People's Republic of China.
Zhi-Wei
ZW
Zhou
Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, Guizhou, People's Republic of China.
Zhi-Xu
ZX
He
Research Center for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing, People's Republic of China.
Xueji
X
Zhang
Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USA.
Tianxin
T
Yang
Department of Colorectal Surgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China.
Yin-Xue
YX
Yang
Cancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing, People's Republic of China.
Dong
D
Wang
Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA.
Shu-Feng
SF
Zhou
Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China.
Jia-Xuan
JX
Qiu
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D051267:NF-E2-Related Factor 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009285:Naphthoquinones / Q000494:pharmacology*; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D060066:Protein Interaction Maps; D021381:Protein Transport; D040901:Proteomics / Q000379:methods; D015398:Signal Transduction / Q000187:drug effects*; D000077195:Squamous Cell Carcinoma of Head and Neck; D013997:Time Factors; D014062:Tongue Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D009285:Naphthoquinones; C014758:plumbagin
EMT; Nrf2; PLB; SILAC; stemness; tongue squamous cell carcinoma