Cl2 transport in an immortalized human epithelial cell line (NCM460) derived from the normal transverse colon

Sahi, Jasminder, Selvaraj G. Nataraja, Thomas J. Layden, Jay L. Goldstein, M. P. Moyer, and Mrinalini C. Rao. Cl2 transport in an immortalized human epithelial cell line (NCM460) derived from the normal transverse colon. Am. J. Physiol. 275 (Cell Physiol. 44): C1048–C1057, 1998.—Cells of a newly described, immortalized, epithelial, human transverse colonic cell line, NCM460, reach ,90% confluence on plastic and develop transepithelial resistances of 120–250 V · cm2 on porous substrates. Its utility as a model for the transverse human colon was validated by comparing second messenger-mediated Cl2 transport, using the fluorescent probe 6-methoxy-quinolyl acetoethyl ester, in NCM460 cells and colonocytes isolated from human transverse crypts. Basal Cl2 influx was increased (P , 0.01) by PGE1 (1 μM), forskolin (1 μM), 8-bromoadenosine 3858-cyclic monophosphate (100 μM), heat-stable Escherichia coli enterotoxin (STa; 1 μM), 8-bromoguanosine 3858-cyclic monophosphate (100 μM), histamine (1 μM), and phorbol 12,13-dibutyrate (1 μM) in both cell types. The Cl2 channel blocker diphenylamine 2-carboxylic acid (50 μM) and the Na1-K1-2Cl2 cotransport inhibitor furosemide (1 μM), but not the K1 channel blocker Ba21 (3 mM), inhibited these Cl2 permeabilities. These cells possess transcripts for cystic fibrosis transmembrane conductance regulator, Na1-K1-2Cl2 cotransporter, STa receptor, and intestine-specific cGMP-dependent protein kinase II. Thus cAMP-, cGMP-, and Ca21-dependent secretagogues act on NCM460 and primary colonocytes to stimulate Cl2 transport. This validates the utility of NCM460 as a model for transverse colonic crypts and is the first demonstration of a colonic cell line whose origin is known.