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. 2015 Mar 3;17(1):32. doi: 10.1186/s13058-015-0540-0

Table 1.

Changes in protein levels and phosphorylation pre- and post-metformin a

Variable Premetformin Postmetformin Change P-value
Median (Q1, Q3) Median (Q1, Q3) Median (Q1, Q3)
Insulin receptor 4.5 (3, 6) 4 (2, 5) 0 (−1, 0) 0.0375
OCT1 ND 7 (6, 7) ND ND
Cytoplasmic p-Akt (S473) 6 (5.5, 7) 3 (3, 5) −2 (−3, −1) <0.0001
Nuclear p-Akt (S473) 4 (2, 5.5) 3 (2, 4.5) 0 (−2, 1) 0.206
Overall p-Akt (S473) 5 (4, 6) 3.5 (2.5, 4.5) −1.5 (−2.5, −0.2) 0.0001
p-ERK (T202/Y204) 7 (6, 7) 4 (3, 6) −2 (−4, 0) <0.0001
p-AMPK (T172) 7 (5.2, 7) 5 (4, 6) −1.5 (−3, 0) 0.0034
p-ACC (S79) 5 (4, 6) 4 (3, 5) −1 (−2, 1) 0.0193

aND, Not determined; OCT1, Organic cation transporter 1; p-ACC, Phosphorylated acetyl coenzyme A carboxylase; p-AMPK, Phosphorylated AMP-activated protein kinase; p-ERK, Phosphorylated extracellular signal-regulated kinase. The median, first quartile (Q1) and third quartile (Q3) data are listed. Allred scoring was used for each protein. OCT1 expression was examined only in the post-metformin treatment surgical specimens. The P-values are derived from Wilcoxon signed-rank tests, which test whether the change scores are distributed symmetrically around zero. The median change for the insulin receptor (IR) registered as zero because of the discrete nature of the data, but the change in IR expression was not symmetric around zero (P = 0.04 by Wilcoxon signed-rank test), with 18 of 38 tumors registering a reduction versus 8 that increased (no change in 12, and 1 unevaluable).