Maspin highlights colorectal serrated polyps: preliminary findings.

AIMS Maspin, a 42-kDa serine proteinase inhibitor, is a tumor suppressor protein that stimulates apoptosis and inhibits motility, invasion and cancer metastasis. Mutant maspin leads to partial loss of tumor suppressor function, decreased susceptibility to apoptosis and to malignant progression. We recently found maspin expression (ME) in the cytoplasm of serrated colonic lesions, such as hyperplastic polyps (HP) and sessile serrated adenoma/polyps (SSA/P). MATERIALS AND METHODS ME was investigated in 10 colorectal lesions: three HP, three SSA/P and four conventional colorectal adenomas (CCRA). RESULTS Widespread cytoplasmic ME (comprising the entire height and width of the lesion) was present in the three HP and in the three SSA/P. In contrast, ME was only focally expressed in the four CCRA. ME was not present in the normal mucosa adjacent to those lesions. CONCLUSION These preliminary findings suggest that maspin might be of help in discriminating between serrated colonic lesions (HP and SSA/P) and CCRA.