Vital immunostaining of human gastric and colorectal cancers grafted into nude mice: a preclinical assessment of a potential adjunct to videoendoscopy

Videoendoscopy has not significantly advanced diagnostic accuracy beyond th at attainable by convention at fiberscopy, with respect to microcarcinomas of the digestive tract. We suspected that after the labeling of these lesio ns with an agent detectable by videoendoscope, digital processing of the im ages could facilitate endoscopic diagnosis of microcarcinomas. We have deve loped a navel antibody labeled with an indocyanine green (ICG) derivative t hat is evident by videoendoscope. However, the binding of such an exogenous antibody in vivo to tumor surfaces has not been described. In this prelimi nary study, after transplanting human gastric cancer or colorectal cancer i nto nude mice, we successfully bound the tumors in vivo with an anti-MUC1 m ucin antibody, as subsequently confirmed by the performing of immunohistoch emistry with a secondary antibody. The antibody labeled with an ICG derivat ive may therefore be clinically useful in detecting gastrointestinal microc arcinoma by videoendoscopy.