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TNF‐α Drives Matrix Metalloproteinase‐9 in Squamous Oral Carcinogenesis
Author(s) -
Hohberger Laurie,
Wuertz Beverly R. K.,
Xie Hongwei,
Griffin Tim,
Ondrey Frank
Publication year - 2008
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1097/mlg.0b013e318174e09b
Subject(s) - carcinogenesis , tumor necrosis factor alpha , microbiology and biotechnology , cancer research , reporter gene , biology , luciferase , matrix metalloproteinase , real time polymerase chain reaction , gene expression , gene , chemistry , immunology , transfection , biochemistry
Objectives/Hypothesis: It is well known that invasion is a seminal event in the progression of oral and other head and neck carcinoma sites. We have previously demonstrated tumor necrosis factor (TNF)‐α and its dependent cytokines are upregulated in saliva during oral carcinogenesis. TNF‐dependent events stimulate nuclear factor (NF)‐κB and many NF‐κB‐dependent genes are associated with cancer progression. Materials and Methods: In the present study, we examined NF‐κB stimulation of matrix metalloproteinase (MMP)‐9 in a precancerous keratinocyte cell line that models leukoplakia (Rhek cells). We stimulated Rhek cells with both TNF‐α and phorbol myristate acetate, known stimulants of NF‐κB. We then assayed MMP‐9 transcription and secretion by luciferase reporter genes, quantitative real‐time polymerase chain reaction, and fluorometric enzyme‐linked immunosorbent serologic assay. Results: We discovered that the MMP‐9 promoter was significantly stimulated by phorbol myristate acetate and TNF‐α on luciferase reporter gene assays. Further, we uncovered that functional MMP‐9 promoter activation was accompanied by significant increases in MMP‐9 gene expression, as judged by quantitative real‐time polymerase chain reaction. Functional activation of the MMP‐9 protein was stimulated by TNF‐α and PMA on a fluorescent enzyme‐linked immunosorbent serologic assay. Finally, we searched our salivary proteomic database for increases in MMP‐9 and discovered it was the third most significant protein in salivas of oral cavity cancer patients over normal controls. Conclusions: We conclude the milieu cytokine, TNF‐α, has the capacity to provide stimulation of events related to early invasion of oral cavity cancer, as judged by its ability to stimulate MMP‐9.