Immunohistochemical analysis of α1-integrins in cervical cancer

OBJECTIVE: The purpose of this study was to determine and compare the expression of the α2-, α3-, α4- and α5-subunits of the β1-family of integrins in both the normal and the carcinomatous cervix. STUDY DESIGN: A total of 22 solid tissue specimens (18 cancer and 4 normal) were analyzed immunohistochemically. The double-stain technique used an avidin-biotin complex kit to identify the various integrins and alkaline phosphatase-anti-alkaline phosphatase kit to identify the epithelial cells. Staining intensity, the main outcome measured, was graded as absent, weak, moderate, or strong. Statistical analysis was performed with the Wilcoxon rank sum test for no nonparametric data. RESULTS: The α2- and α3-integrins stained the normal cervix epithelilum more intensely than the stroma (p = 0.03). The α4- and α5-integrins stained both the stroma and the normal epithelium similarly. The α2-integrin was absent in the stroma of all 18 cancer specimens despite being present in the epithelial regions of 14 to 18 cancers. The α3-integrin had a greater staining intensity in the stroma of the cancers than in the epithelial regions (p = 0.002). Both α4- and α5-integrins were absent in the epithelial regions of the cancers but present in the stroma. CONCLUSIONS: The distribution and intensity of integrin expression in cervical cancer differ from their expression in the normal cervix. In particular, the fibronectin receptors, α4 and α5, were absent in the epithelial regions of the cervical cancers, and α3 also had diminished expression in the malignant epithelium. These changes correlate well with the changes expected in malignant transformation