Immunohistochemical analysis of BRCA1 expression in normal human buccal cells.

While tumor suppressor properties of BRCA1 are well documented, less is understood concerning the normal function of this protein in healthy adult tissues. We demonstrate here that BRCA1 protein is expressed in human buccal cells. Expression of BRCA1 mRNA transcripts in buccal cells was confirmed by PCR of reverse transcribed RNA. Three BRCA1 antibodies, D20, MS110 and MS13, reacted positively with cytospin deposited buccal cells, demonstrating apparent cytoplasmic and nuclear distribution of BRCA1 protein. Double antibody immunofluorescent, binding of D20 and MS110 was differentially distributed. We conclude that buccal cells provide a cell source for exploration of BRCA1 protein function in normal human adults.