The leukocyte antigen CD43 is expressed in different cell lines of nonhematopoietic origin.

CD43 is an abundant transmembrane sialoglycoprotein in leukocyte-type cell lines, but it has also been suggested to be present in colon adenomas and colon carcinomas. We have now shown that CD43 is expressed in a variety of cell lines of different origins (CaSKI, A549, 293, MTSV1-7, MCF7, HT-1080, Jurkat, K562, COLO 205, HT-29, Caco-2, DLD-1 and SW480). The level of expression of CD43 mRNA was analyzed by reverse transcriptase-polymerase chain reaction and that of the protein by immunoprecipitation and Western blot, flow cytometry and confocal microscopy using two monoclonal anti-CD43 antibodies (L10 and 4D2). As all cell lines expressed CD43, it is suggested that CD43 has a more fundamental function than previously believed and thus cannot be considered only as a specific leukocyte marker.