Oral administration of metformin inhibited pancreatic cancer xenograft growth.

<p>A, Xenograft at sacrifice. Eight hundred milligrams per liter of metformin was diluted in the drinking water of <i>nu</i>/<i>nu</i> mice 72 h before injection of pancreatic cancer cells. Mice were sacrificed 18 or 24 days after the implantation. Xenografts from mice treated with oral metformin were much smaller than those from untreated mice. B, Effect of oral administration of metformin on growth of xenografts. Eight hundred milligrams per liter of metformin was diluted in the drinking water of <i>nu</i>/<i>nu</i> mice 72 h before injection of pancreatic cancer cells. Tumors were measured every 3 days after the injection and tumor volume (V) was calculated according to V = (length × width²)/2. Xenograft growth was significantly inhibited by oral administration of metformin. Error bars represent the standard deviation. ^*<i>P</i><0.05.