Interplay Between Keratin and Vimentin Expression in Oral Cancer

<p>Previous research in our laboratory found that inhibiting expression of vimentin, a marker of epithelial-to mesenchymal transition, inhibited cell growth and motility in vitro and in vivo. Tumors derived from vimentin knockdown cells showed features of epithelial redifferentiation and increased expression of differentiation-specific keratins. It is unknown what causes re-expression of keratins when vimentin is inhibited. Although, canonical Wnt signaling may activate NF-κB and repress of keratin and/or induce vimentin expression through β-catenin. We hypothesize that downregulation of differentiation-specific keratins contributes to tumor progression, mediated directly or indirectly by expression of vimentin. Vimentin-negative HN4 cells were transfected with plasmids encoding wild-type, PKCε-phosphomimetic, or unphosphorylatable versions of vimentin. Expression of vimentin was confirmed by western blot and immunofluorescence. Effects on cell growth and motility were determined using MTT, cell proliferation, and wound-closure assays. These results indicate that mutation of vimentin PKCε-phosphorylation sites cause changes in proliferation and filament assembly. Treatment of cells with an NF-κB inhibitor or 5-Aza-C, which allows re-expression of the Wnt inhibitor DKK3, led to a decrease in proliferation. These results suggest that inhibiting Wnt signaling removes the inhibition on GSK-3β and prevents activation of NF-κB, which decreases proliferation.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Physiology

Year dc:date.available

2010

Author dc:creator

• McGinn, Mary Catherine

Contributors dc:contributor

• W. Andrew Yeudall

• vimentin
• keratin
• oral cancer
• Wnt signaling
• Life Sciences
• Physiology

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/49

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1048