We have demonstrated for the first time, by Northern analysis, the presence of the S-100 calcium binding proteins MRP8 (also called ''cystic fibrosis protein') and MRP14 mRNAs in cultured human tracheal gland cells, obtained from normal and cystic fibrosis (CF) patients. A significant increase of these mRNAs in cells of CF origin (as well as that of CFTR mRNA) is shown. These results allow us to assume a potential pretranslational regulation of MRP8 and MRP14 gene expression related to the presence of a mutated CFTR gene. (C) 1994 Academic Press, Inc.