MUCIN GENES EXPRESSED BY HUMAN FEMALE REPRODUCTIVE-TRACT EPITHELIA

Recent characterizations of mucins at the molecular level indicate tha t at least eight mucin genes are expressed by epithelia of mucosal sur faces. The purpose of this study was to determine whether these cloned mucins, designated MUC1, MUC2, MUGS, MUC4, MUC5AC, MUC5B, MUC6, and M UC7, are expressed by epithelia of the female reproductive tract. Nort hern blot analysis, in situ hybridization, and immunohistochemistry we re performed using RNA and tissue from surgically removed human reprod uctive tract specimens including endocervix, ectocervix, vagina, endom etrium, and fallopian tube. Complementary DNA to the tandem repeat reg ions of MUCs 1, 2, 3, 5AC, 5B, and 6; oligonucleotides to the tandem r epeat regions of MUCs 4, 6, and 7; and antibodies that recognize uniqu e mucin tandem repeats were used. The data demonstrate that the endoce rvical epithelium expresses five mucin genes: MUCs 1, 4, 5AC, 5B, and 6. The ectocervical and vaginal epithelia express MUCs 1 and 4, althou gh vaginal expression of MUC4 appears patchy. Endometrial epithelium e xpresses MUC1 and low amounts of MUC6. MUC6 immunoreactivity was detec ted only in scattered endometrial glands located in the basalis region in specimens from pre- and postmenopausal women. The only mucin detec ted in the fallopian tube was MUC1. These data indicate that the endoc ervical epithelium expresses multiple mucin genes and that the stratif ied epithelia of the ectocervix and vagina also produce mucins that ma y function in reproductive processes and protection of the reproductiv e tract tissues.