Fisetin inhibits human melanoma cell invasion through promotion of mesenchymal to epithelial transition and by targeting MAPK and NFκB signaling pathways.
Malignant melanoma is responsible for approximately 75% of skin cancer-related deaths. BRAF plays an important role in regulating the mitogen-activated protein kinase (MAPK) signaling cascade in melanoma with activating mutations in the serine/threonine kinase BRAF occurring in 60-70% of malignant melanomas. The BRAF-MEK-ERK (MAPK) pathway is a key regulator of melanoma cell invasion. In addition, activation of NFκB via the MAPK pathway is regulated through MEK-induced activation of IKK. These pathways are potential targets for prevention and treatment of melanoma. In this study, we investigated the effect of fisetin, a phytochemical present in fruits and vegetables, on melanoma cell invasion and epithelial-mesenchymal transition, and delineated the underlying molecular mechanism. Treatment of multiple human malignant melanoma cell lines with fisetin (5-20 µM) resulted in inhibition of cell invasion. BRAF mutated melanoma cells were more sensitive to fisetin treatment, and this was associated with a decrease in the phosphorylation of MEK1/2 and ERK1/2. In addition, fisetin inhibited the activation of IKK leading to a reduction in the activation of the NFκB signaling pathway. Treatment of cells with an inhibitor of MEK1/2 (PD98059) or of NFκB (caffeic acid phenethyl ester) also reduced melanoma cell invasion. Furthermore, treatment of fisetin promoted mesenchymal to epithelial transition in melanoma cells, which was associated with a decrease in mesenchymal markers (N-cadherin, vimentin, snail and fibronectin) and an increase in epithelial markers (E-cadherin and desmoglein). Employing three dimensional skin equivalents consisting of A375 cells admixed with normal human keratinocytes embedded onto a collagen-constricted fibroblast matrix, we found that treatment of fisetin reduced the invasive potential of melanoma cells into the dermis and increased the expression of E-cadherin with a concomitant decrease in vimentin. These results indicate that fisetin inhibits melanoma cell invasion through promotion of mesenchymal to epithelial transition and by targeting MAPK and NFκB signaling pathways.
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Harish Chandra
HC
Pal
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Samriti
S
Sharma
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Leah Ray
LR
Strickland
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America ; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Santosh K
SK
Katiyar
Department of Pediatrics Infectious Disease, Children's of Alabama, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Mary E
ME
Ballestas
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America ; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Mohammad
M
Athar
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America ; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Craig A
CA
Elmets
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America ; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
Farrukh
F
Afaq
D015703:Antigens, CD; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D054338:Cell Transdifferentiation / Q000187:drug effects*; D004354:Drug Screening Assays, Antitumor; D005419:Flavonoids / Q000494:pharmacology*; D044948:Flavonols; D006801:Humans; D020935:MAP Kinase Signaling System; D008545:Melanoma; D016328:NF-kappa B / Q000378:metabolism; D009361:Neoplasm Invasiveness; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D014746:Vimentin / Q000378:metabolism
D015703:Antigens, CD; D000972:Antineoplastic Agents, Phytogenic; C513384:CDH1 protein, human; D015820:Cadherins; D005419:Flavonoids; D044948:Flavonols; D016328:NF-kappa B; D014746:Vimentin; C017875:fisetin