Immunhistochemical analysis for expression of calpain 1, calpain 2 and calpastatin in endometrial cancer.

Calpains (CAPN) are intracellular, non-lysosomal cytoplasmic cysteine endopeptidases and they are expressed ubiquitously. Their endogenous specific inhibitor is calpastatin. When calcium is present, calpastatin and calpain attach to each other, inhibiting the protease. The calpain system plays an important role in many processes including apoptosis, necrosis, ischaemia and exocytosis. The role of calpains in pathogenesis or further tumour progression has been proved in related studies. This study focused on the expression of the enzymes calpain 1, calpain 2 and the inhibitor calpastatin in normal and malignant endometrial tissue.Immunohistochemical stainings were performed on paraffin slices and staining intensity, percentage of positive cells and international ratio score were evaluated.The endometrial carcinoma showed a higher expression of calpastatin than benign endometrial tissue.