Intraperitoneal administration of an adenovirus vector carrying REIC/Dkk-3 suppresses peritoneal dissemination of scirrhous gastric carcinoma.

Expression levels of the novel tumor suppressor gene REIC/Dkk-3 are reduced in many human cancers. We have previously showed that an adenovirus vector carrying REIC/Dkk-3 (Ad-REIC) induced apoptosis of cancer cells selectively and exerted bystander antitumor effects via ER stress. We examined possible effects of Ad-REIC in a peritoneal dissemination model of scirrhous gastric carcinoma (SGC). Among various types of gastric cancer, SGC continues to be associated with the worst prognosis due to a high incidence of metastases in the peritoneal cavity. We found that a single intraperitoneal injection of Ad-REIC suppressed tumor dissemination and disease progression. Immunomodulation by Ad-REIC led to recruitment of natural killer cells inside tumor nodules. We conclude that Ad-REIC gene therapy may be a potential tool in combinatorial approaches to achieve curative effects in SGC.