ObjectiveTo detect the protein expression of SHH and its downstream transcriptional factor GLI1 in Peutz-Jeghers syndrome (PJS) and to investigate the roles of SHH and GLI1 in the development and carcinogenesis of PJS polyps. MethodsImmunohistochemical (IHC) staining was employed to detect the expression and localization of SHH and GLI1 protein in 20 PJS polyp samples, 25 adenomatous polyp tissues, 25 colon adenocarcinoma samples, and 20 normal intestinal mucosal tissues. ResultsIHC revealed that SHH protein and GLI1 protein were mainly localized on cell membrane and in the cytoplasm, and the nuclear staining of GLI1 protein in the colon adenocarcinoma was increased. The expression of the two proteins gradually increased in order in the normal intestinal mucosa, PJS polyp, adenomatous polyp, and colon adenocarcinoma(P<0.001). Spearman rank correlation showed that SHH expression was significantly correlated with GLI1 expression in PJS polyp(rp=0.503,P=0.024) . ConclusionSHH-GLI1 is present in the tissues of normal intestinal mucosa, PJS polyp, adenomatous polyp, and colon adenocarcinoma, and the expression has an increasing tendency in the above tissues, indicating SHH-GLI1 signal pathway may be associated with the development and carcinogenesis of PJS polyp.