(-)-Epicatechin stimulates caspase 3 cleavage and expression in Panc-1 cells.

<p>Panc-1 cells were exposed to 0 or 20 µM (-)-epicatechin for 1 hour, then exposed to 6 Gy of radiation, and incubated for 72 hours. (-)-Epicatechin stimulates pro-caspase 3 expression and cleavage.</p

(-)-Epicatechin is a flavanol that selectively stimulates mitochondrial respiration in pancreatic cancer cells.

<p>(A) Oxygen consumption by cytochrome c oxidase (COX) from Panc-1 cells exposed to different (-)-epicatechin concentrations. Turnover is defined as consumed O₂ (nM)/(min · total protein (mg)). Respiration rates are increased by (-)-epicatechin in a concentration-dependent manner. *p<0.05, compared to 0 µM (-)-epicatechin. (B) Oxygen consumption by cytochrome c oxidase (COX) from human normal fibroblast (HNF) cells exposed to 0 or 100 µM (-)-epicatechin. Respiration rates are not increased by 100 µM (-)-epicatechin.</p

(-)-Epicatechin does not sensitize normal cells to radiation.

<p>(A) 20 µM (-)-Epicatechin does not sensitize HNF cells to radiation (REF = 0.9). (B) (-)-Epicatechin alone does not inhibit colony formation in HNF (p>0.05).</p

(-)-Epicatechin inhibits p21 expression and does not stimulate checkpoint kinase protein 2 phosphorylation at threonine 68 in HNF cells.

<p>(A) (-)-Epicatechin inhibits p21 expression. Protein levels in 20 µM (-)-epicatechin treated samples were normalized to samples treated with 6 Gy, and *p<0.05. (B) 20 µM (-)-epicatechin does not stimulate Chk2 phosphorylation. Protein levels in (-)-epicatechin treated samples were normalized to samples that were treated with 6 Gy.</p

The effect of (-)-epicatechin on ETC protein expression in combination with radiation.

<p>(A) A representative blot for ETC protein expression in Panc-1 cells that were treated with 0–200 µM (-)-epicatechin and 0 or 6 Gy. (B) (-)-Epicatechin alone does not significantly change ETC protein expression. Protein levels are normalized to the untreated control. (B) (-)-Epicatechin induced minimal changes in ETC protein expression when combined with 6 Gy. Values were normalized to 6 Gy alone, and * p<0.05 relative to 6 Gy/0 µM (-)-epicatechin.</p

(-)-Epicatechin sensitizes cancer cells to radiation.

<p>(A) (-)-Epicatechin sensitizes Panc-1 cells to radiation with an average REF = 1.7 (B) (-)-Epicatechin sensitizes U87 cells to radiation with an average REF of 1.5. (C) (-)-Epicatechin sensitizes MIA PaCa-2 cells to radiation with an average REF = 1.2.</p

(-)-Epicatechin stimulates checkpoint kinase protein 2 phosphorylation at threonine 68 and p21 expression in Panc-1 cells.

<p>(A) (-)-Epicatechin stimulates p21 expression. Protein levels in 20 µM (-)-epicatechin treated samples were normalized to samples treated with 6 Gy. (B) 20 µM (-)-epicatechin stimulates Chk2 phosphorylation. Protein levels in (-)-epicatechin treated samples were normalized to samples that were treated with 6 Gy, and *p<0.05.</p