Successful xenografting of cryopreserved primary pancreatic cancers

In order to assess the suitability of cryopreserved neoplastic tissues for xenografting into nude (nu/nu) mice, we compared the take rate in 28 sample s of pancreatic ductal carcinoma. Eleven fresh samples were implanted in nu /nu mice, and 17 were frozen in cryopreserving solution and implanted at a later time. All samples were examined for the presence of neoplastic tissue in cryostat sections. A total of 15 tumors grew in the animals; five from the freshly implanted samples and ten from those cryopreserved. Ten xenogra fted tumors were characterized for alterations in p53, K-rns, and p16 genes , which were found in six, eight, and nine cases, respectively. Our results demonstrate that the take rate for xenografting is comparable between cryo preserved and fresh tissue samples. The procedure allows for the exchange o f tumor material between institutions and permits the establishment of cent ralized facilities for the storage of an array of different primary tumor s amples suitable for the production of in vivo models of cancers.