Increased fluid secretion after adenoviral-mediated transfer of the human aquaporin-1 cDNA to irradiated miniature pig parotid glands

The treatment of most head and neck cancer patients includes ionizing radiation (111). Salivary glands in the IR field suffer irreversible damage. Previously, we reported that adenoviral (Ad)mediated transfer of the human aquaporin-1 (hAQP1) cDNA to rat submandibular glands following IR restored salivary flow to near normal levels. It is unclear if this strategy is useful in larger animals. Herein, we evaluated AdhAQP1-mediated gene transfer after parotid gland IR (20 Cy) in the miniature pig. Sixteen weeks following IR, salivation from the targeted gland was decreased by > 80%. AdhAQP1 administration resulted in a dose-dependent increase in parotid salivary flow to similar to 80% of pre-IR levels on day 3. A control Ad vector was without significant effect. The effective AdhAQP1 dose was 2.5 x 105 pfu/mu l infusate, a dose that leads to comparable transgene expression in murine and minipig salivary glands. Three days after Ad vector administration little change was observed in clinical chemistry and hematology values. These findings demonstrate that localized delivery of AdhAQP1 to IR-damaged salivary glands increases salivary secretion, without significant general adverse events, in a large animal model.