Changes in the titer of anti-phospho-eEF2 aAb as a marker of early tumor progression in mice and humans.

<p><b>A.</b> Human and mouse amino acid sequences of eEF2 in the region of Thr56. The 12 residues corresponding to the synthetic peptide (phosphorylated on Thr56) used in our immunoassay are indicated (red frame); note the perfect identity between mouse and human sequences. <b>B.</b> Detection of commercial anti-phospho-Thr56 eEF2-antibodies using our immunoassay; dashed lines show the 95% confidence band of the linear regression. <b>C.</b> Detection of anti-phospho-Thr56 eEF2 aAb in the serum of control or HCT116 tumor-bearing mice (n = 3). ***P<0.001. <b>D.</b> Time course of HCT116 tumor growth as determined by measurements of tumor diameters (n = 7 per group). <b>E.</b> Detection of anti-phospho-Thr56 eEF2 aAb at the indicated time of HCT116 tumor progression. *P<0.05, **P<0.01, ***P<0.001 (n = 6–7 per group). Note that at day 7 post-implantation, tumors are not detectable (see panel D) but a positive signal is detected in the immunoassay. <b>F.</b> Graph represents the detection of anti-phospho-Thr56 eEF2 aAb in the serum of control subjects (n = 6) and patients with adenomatous polyps (n = 14) or carcinoma (n = 9). *P<0.05, **P<0.01. Of note, K-means clustering identified two subpopulations of patients (see black and red symbols) among individuals diagnosed with adenomatous polyps (P<0.001) and carcinoma (P<0.01); the same partition was observed in 100 independent runs by varying the random initialization of K-means algorithm.