Induction of NCAM expression in mouse olfactory keratin-positive basal cells in vitro

The expression of neural cell adhesion molecule (NCAM) by olfactory keratin+ basal cells was investigated in vitro. In primary cultures from embryonic day 14.5 or newborn mouse olfactory epithelium (OE), flat keratin+ basal cells were negative for NCAM-immunostaining. Transforming-growth factor-beta 1, beta 2 (TGF-beta 1, beta 2) or a high concentration of Ca2+ induced these cells to express NCAM. We obtained a cell line, designated DBC1.2, from embryonic day 14.5 mouse OE. All DBC1.2 cells were positive for keratin-immunostaining, whereas nearly all cells were negative for NCAM-immunostaining. Therefore, DBC1.2 cells seemed to derive from dark basal cells. DBC1.2 cells were also induced to express NCAM by the treatment with TGF-beta s or a high Ca2+ concentration. Western blotting revealed that the components of the NCAM expressed by DBC1.2 were 120 and 140 kDa, but not 180 kDa, isoforms. Since NCAM is the cell adhesion molecule mainly expressed in nervous tissues, these results suggest a cell lineage relationship or interactions between olfactory keratin+ basal cells and olfactory sensory neurons.