Figure 2
From: Clusterin expression can be modulated by changes in TCF1-mediated Wnt signaling
Evaluation of dnTCF-Wnt-model system: Expression of exogenous gene products and phenotypic change. Doxycycline-inducible dominant negative (dn) versions of TCF1 and TCF4 factors, the effectors of the Wnt pathway, were over-expressed in stably transfected LS174T derived cell lines. (A) Proliferation was halted in LS174T derived cell lines after induction of both dnTCFs. This was visualised by methyl violet staining of cell cultures after 5 days of induction. (B) Similar results were obtained by manually counting cells in a haemocytometer after cells had been cultured in the presence (+) or absence (-) of induction for 4 days. Data are presented as the mean ± standard deviation from 3 separate experiments. (C) Induction of exogenous gene products, dnTCFs, was detected by western blot with cell lysates from LS174T derived cell lines 0, 12, and 24 hr after induction. Control cells are LS174T cells without any dnTCF expression vector. (D) Both dnTCF1 and dnTCF4 abrogate β-catenin/TCF driven transcription of the Wnt-target gene, c-MYC, as analyzed by western blot with cell lysates from LS174T derived cell lines 0 and 12 hr after induction.