Figure 5

MT1G inhibited the activity of PI3K/Akt pathway and phosphorylation of tumor suppressor Rb in thyroid cancer cells. Thyroid cancer cell lines K1 and FTC133 stably transfected with pEGFP-N1-MT1G or empty vector were starved overnight and harvested. Cell lysates were collected and subjected to Western blotting assays. (A) The antibodies against phospho-Akt^Ser473 (p-Akt), total-Akt (t-Akt), and Mdm2 were used to determine the effect of MT1G on the activity of PI3K/Akt signaling. (B) The effect of MT1G on the p53 signaling pathway was determined by blotting p53 and its downstream targets, p21, Bak and Smac. (C) The expression of E-cadherin and Vimentin were used to evaluate the effect of MT1G on cell migration and invasion. (D) The antibody against phospho-Rb^Ser811 (p-Rb) was used to determine the effect of MT1G on the Rb/E2F signaling. Shown in the lower portion of the panel is a quantitative illustration of levels of p-Rb protein using densitometry to measure the density of the corresponding bands on Western blot shown in the upper portion of the panel. GAPDH was used for quality control of Western blotting.