BACKGROUND: T cell factor 4 (TCF-4) mediates a nuclear response to wingless/int (Wnt) signals by interacting with beta-catenin. Axis inhibition protein (axin) is an important negative regulator of the Wnt signaling pathway. Our aims were to examine the relationship between axin and TCF-4 and to explore the effects of axin on the development of lung cancer. METHODS: Expression levels of axin and TCF-4 were examined in 107 lung cancer specimens by immunohistochemistry. The axin gene was transfected into lung cancer BE1 cells. The expression levels of axin, beta-catenin, and TCF-4 were detected with immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) experiments. Apoptosis, proliferation, and the invasive ability of lung cancer cells were examined using flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), and Matrigel invasive assays. RESULTS: Preserved axin expression correlated negatively with TCF-4 expression (P = .031). Axin expression differed with respect to degree of differentiation (P = .025) and histological tumor type (P = .031). TCF-4 expression differed relative to tumor, node metastasis (TNM) stage (P = .024). BE1 cells transfected with axin (BE1-axin cells) exhibited a significant decrease in TCF-4 expression. The level of apoptosis in BE1-axin cells was significantly increased, while the proliferative and invasive abilities of BE1-axin cells were decreased. CONCLUSION: These results suggest that reduced expression of axin or augmented expression of TCF-4 is associated with the malignant behavior of lung cancers. Overexpression of axin can downregulate expression of TCF-4 and can inhibit the ability of lung cancer cells to proliferate and invade.
BACKGROUND:T cell factor 4 (TCF-4) mediates a nuclear response to wingless/int (Wnt) signals by interacting with beta-catenin. Axis inhibition protein (axin) is an important negative regulator of the Wnt signaling pathway. Our aims were to examine the relationship between axin and TCF-4 and to explore the effects of axin on the development of lung cancer. METHODS: Expression levels of axin and TCF-4 were examined in 107 lung cancer specimens by immunohistochemistry. The axin gene was transfected into lung cancer BE1 cells. The expression levels of axin, beta-catenin, and TCF-4 were detected with immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) experiments. Apoptosis, proliferation, and the invasive ability of lung cancer cells were examined using flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), and Matrigel invasive assays. RESULTS: Preserved axin expression correlated negatively with TCF-4 expression (P = .031). Axin expression differed with respect to degree of differentiation (P = .025) and histological tumor type (P = .031). TCF-4 expression differed relative to tumor, node metastasis (TNM) stage (P = .024). BE1 cells transfected with axin (BE1-axin cells) exhibited a significant decrease in TCF-4 expression. The level of apoptosis in BE1-axin cells was significantly increased, while the proliferative and invasive abilities of BE1-axin cells were decreased. CONCLUSION: These results suggest that reduced expression of axin or augmented expression of TCF-4 is associated with the malignant behavior of lung cancers. Overexpression of axin can downregulate expression of TCF-4 and can inhibit the ability of lung cancer cells to proliferate and invade.
Authors: Yi Chen; Mike Gruidl; Elizabeth Remily-Wood; Richard Z Liu; Steven Eschrich; Mark Lloyd; Aejaz Nasir; Marilyn M Bui; Emina Huang; David Shibata; Timothy Yeatman; John M Koomen Journal: J Proteome Res Date: 2010-08-06 Impact factor: 4.466