Aberrant connexin 43 and 26 expression in cervical dysplasia.

OBJECTIVE: To determine whether connexin (Cx) expression is altered in cervical dysplasia. STUDY DESIGN: Cx proteins form gap junctions and are expressed in squamous epithelia including ectocervix. We used multispectral imaging to perform a quantitative immunohistochemical survey of Cx43 Cx26 in 37 archival human cervical specimens. RESULTS: Cx43 expression was very low in normal cervix (100%), but was increased in low-grade squamous intraepithelial lesions (LSILs) (64%), primarily in a parabasal distribution. High-grade squamous intraepithelial lesions (HSILs) showed weak full-thickness Cx43 staining (53%) or lacked Cx43 (47%). An aberrant increase in Cx43 expression was often (62%) present in histologically normal areas of specimens that elsewhere harbored dysplasia. Cx26 was highly expressed in the basal layer of normal ectocervix (100%). In LSIL, 57% showed a decrease in Cx26 and the rest showed no change relative to the normal pattern. In HSIL, Cx26 was expressed in the full thickness of the epithelium, at a high level in 80% of cases and a low level in the rest. CONCLUSION: Cx alteration is moderately consistent in cervical dysplasia, and for Cx43 can precede histologic changes. The resulting changes in Cx signaling may be important in the pathogenesis of cervical intraepithelial neoplasia.

Immunohistochemical expression of galectin-3 in benign and malignant thyroid lesions.

CONTEXT: The expression of galectin-3, a human lectin, has been shown to be highly associated with malignant behavior of thyroid lesions. DESIGN: We studied the immunohistochemical expression pattern of galectin-3 in a variety of follicular-derived thyroid lesions (13 benign and 62 malignant), including Hürthle cell and follicular carcinoma, papillary carcinomas and variants, and anaplastic and poorly differentiated carcinomas. RESULTS: Immunoreactivity was strongest in papillary thyroid carcinomas, whereas staining was less intense in Hürthle cell and anaplastic carcinomas, and even weaker in the follicular variant of papillary thyroid carcinoma. Staining was absent or weak in the 3 follicular thyroid carcinomas and was negative in both insular carcinomas. In several tumors, staining was stronger at the advancing invasive edge of the lesion than in the central portion of the tumor. Galectin-3 was also expressed focally and weakly in reactive follicular epithelium and entrapped follicles in chronic lymphocytic thyroiditis. A variety of thyroid lesions showed prominent endogenous, biotin-like activity, which could cause flaws in interpretation if a biotin-detection system were used. CONCLUSION: We conclude that galectin-3 immunostaining, when used in biotin-free detection systems, may be useful as an adjunct to distinguish benign from malignant thyroid lesions.