Is treatment with 6-mercaptopurine for colitis associated with the development of colorectal cancer?

Background: Patients with ulcerative colitis and Crohn's colitis have an increased risk of colon cancer influenced by the duration, extent, and severity of disease. Surveillance colonoscopy serves to detect cancer and precancerous dysplasia at the earliest possible time. Reduction of inflammation should theoretically reduce the development of cancer.

Aquaporin 1 regulates GTP-induced rapid gating of water in secretory vesicles.

The swelling of secretory vesicles has been implicated in exocytosis, but the underlying mechanism of vesicle swelling remains largely unknown. Zymogen granules (ZGs), the membrane-bound secretory vesicles in exocrine pancreas, swell in response to GTP mediated by a G(alpha)i3 protein. Evidence is presented here that the water channel aquaporin-1 (AQP1) is present in the ZG membrane and participates in rapid GTP-induced vesicular water gating and swelling.