Immunohistochemical characterization of FHIT expression in normal human tissues.

Background Fragile histidine triad (FHIT) is a tumor suppressor gene that is commonly inactivated in human tumors. Interestingly, the normal pattern of FHIT expression is largely unknown. Aim This study is aimed to characterize the expression of FHIT protein in normal human tissues. Materials and methods A total of 119 normal human tissue specimens were analyzed for the FHIT expression using immunohistochemistry technique. The inclusion criteria included: normal/inflammatory tissue with no evidence of cellular atypia. Results All studied specimens were stained positively with FHIT and showed either nuclear or cytoplasmic expression. Interestingly, the pattern of FHIT staining was similar among different specimens from each organ. FHIT is located predominantly in the nucleus, although cytoplasmic staining is also present in some cell types. Oral squamous epithelium, breast ductal epithelium, squamous and tubal metaplastic epithelium of the uterine cervix, esophageal squamous epithelium, salivary glands, an...