To determine whether cell growth conditions impacted carbohydrate expressio
n, HT29 cells were gradually transferred from a conventional glucose-contai
ning media to a glucose-free galactose containing media. Indirect immunoflu
orescence on acetone fixed cells showed increased expression of sialyl Lewi
s A antigen (CA19-9), sialyl Lewis C (DUPAN2) and Tn/sialyl-Tn on the surfa
ce of HT29 cells grown in the glucose-free galactose containing media compa
red to those grown in the glucose containing media. Sialyltransferases resp
onsible for the synthesis for these sialylated epitopes were increased in t
he galactose-fed HT29 cells. Media overlying the cells was subjected to iso
pycnic ultracentrifugation in cesium chloride and the fractions derived fro
m both glucose and galactose media with equivalent buoyant densities of 1.5
6 g/L, which are predicted to contain mucin glycoforms, were further separa
ted by HPLC using a Mono-Q anion exchange column. The chromatograph of elue
nt from the sample derived from the cells growing in the galactose containi
ng media showed an increased peak that reacted with the anti-sialyl Lewis A
antibody, CA19-9. These results show that alteration of in vitro culture c
onditions may cause HT29 colonic carcinoma cells to alter the expression of
sialylated carbohydrates.