APC EXPRESSION IN NORMAL HUMAN TISSUES

The tumour suppressor gene APC codes for a 2843-amino acid protein who se precise functions are still poorly understood, This paper describes the development of two nem antisera to APC (to amino- and carboxy-ter minal epitopes) which permit localization of the protein by immunohist ochemistry in archival paraffin sections, The protein is expressed in a wide variety of normal epithelial tissues, Its distribution frequent ly coincides with the location of post-replicative cells within tissue s, Staining patterns demonstrate that the APC protein, although often diffusely cytoplasmic in distribution, may also accumulate in the apic al and immediately subapical regions, or along the lateral margins of certain cells, These results indicate that APC is significant in many tissues in addition to the colorectal epithelium. They are compatible with a function related to signalling at the adherens junction and pos sibly with other more complex roles in cells committed to terminal dif ferentiation. (C) 1997 by John Wiley & Sons, Ltd.