Characterization of mast cells according to their content of tryptase and chymase in normal and neoplastic human uterine cervix.

Mast cells (MC) have been associated with diverse human cancers. The primary function of these cells is to store and release a number of biologically active mediators, including the serine proteases tryptase and chymase. These proteases have been closely related with angiogenesis and tumor invasion, two critical steps during tumor progression. In the present work we analyzed the presence of MC in human uterine cervix from both normal and neoplastic tissues by using metachromatic, immunohistochemical, and enzymohistochemical staining. Tryptase-positive (MCT)- and tryptase/chymase-positive (MCTC)-mast cells were found in both normal and neoplastic tissues. The phenotype predominantly expressed in normal tissues as well as in benign and malignant lesions of the uterine cervix was the MCT. The total number of MC remained constant through the different stages of malignant transformation (cervical intraepithelial neoplasia grade 1-3) but a significant increase in the invasive carcinoma (IC) group was observed, this increase being mainly due to the MCT phenotype. Furthermore, we detected abundant MCT but not MCTC infiltrating tumors in sections of IC. Regarding the potent angiogenic properties described for tryptase, these findings suggest that in advanced stages of malignancy the significant number of MCT distributed within the cervical tissues could provide an effective mechanism to create the abundantly vascularized microenvironment required for tumor cells to proliferate and disseminate.