Sales KU, Giudice FS, Castilho RM, Salles FT, Squarize CH, Abrahao AC, Pinto DS. Cyclin D1-induced proliferation is independent of beta-catenin in head and neck cancer.
Oral Dis 2013;
20:e42-8. [PMID:
23730900 DOI:
10.1111/odi.12124]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 04/04/2013] [Accepted: 04/18/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE
Head and neck squamous cell carcinoma (HNSCC) progression and metastasis have previously been associated with the activation of phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) and Wnt signalling pathways, which lead to the activation of pro-proliferative genes, such as cyclin D1. The current study aims to investigate whether there is a crosstalk between these pathways in HNSCC and which pathway is more likely to regulate cyclin D1.
MATERIAL AND METHODS
Two HNSCC and a control keratinocyte cell lines were treated with EGF and wortmannin to respectively activate and block the PI3K-Akt and Wnt pathways. Partial and total levels of cyclin D1, beta-catenin and Akt were evaluated by Western blotting and immunofluorescence. Twenty-four paraffin-embedded samples of human HNSCC, as well as normal oral mucosa biopsies, were also immunohistochemically evaluated for beta-catenin and cyclin D1 expression.
RESULTS
Following both treatments, change in cyclin D1 protein was correlated with Akt levels only. Cytoplasmic staining for beta-catenin and loss of its membranous expression in the HNSCC invasive areas were found in 92% of the HNSCC biopsies.
CONCLUSION
Taken together, we show that the change in cyclin D1 levels is more likely to be due to the EGFR-Akt pathway activation than due to beta-catenin nuclear translocation.
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