OBJECTIVETo detect the mRNA and protein expression of interferon-inducible transmembrane protein-1 (IFITM1) in Peutz-Jeghers syndrome (PJS) and investigate the role of IFITM1 in the occurrence, development and carcinogenesis of PJS polyps.

METHODSReverse transcription-PCR was employed to detect the mRNA expression of IFITM1 in 16 PJS polyp samples, adenomatous polyp tissues, colon adenocarcinoma samples, and normal intestinal mucosal tissues. The protein expression and localization of IFITM1 in these tissues (32 cases for each) were detected with immunohistochemical (IHC) staining.

RESULTSThe IFITM1 mRNA expression was detected in all these tissues, and the expression intensity increased in the order of normal intestinal mucosa, PJS polyp, adenomatous polyp, and colon adenocarcinoma (F=92.704, P=0.000). IHC revealed that IFITM1 protein was localized mainly on the cell membrane and in the cytoplasm, with increased expression intensity in the same order as its mRNA and showing significant differences between the tissues by several rank-sum test (Kruskal-Wallis H, chi(2)=37.036, p=0.000).

CONCLUSIONThe expression level of IFITM1 is associated with the progression of the carcinogenetic process in PJS polyp, and can be used as a sensitive biomarker for diagnosis and prognostic evaluation of PJS.