Processing of asparagine-linked oligosaccharides is an early biochemical marker of the enterocytic differentiation of HT-29 cells.
The inability of HT-29 cells to undergo an enterocytic differentiation when grown in a glucose-containing (Glc+) medium has been recently correlated to an overall impairment of N-glycan processing. These results were obtained using confluent HT-29 cells in which the differentiation characteristics are fully expressed under differentiation permissive conditions (glucose-deprived medium, Glc-). Whether these changes of N-glycan processing appear progressively during the cell growth or are already present from the beginning of the culture was investigated in this work by comparing the actual status of N-glycan processing in both exponentially growing Glc+ and Glc- HT-29 cells. Under these conditions, HT-29 cells do not express any characteristics of enterocytic differentiation, even when grown in differentiation permissive conditions. We show here that the conversion of high-mannose to complex glycoproteins is, however, severely reduced in HT-29 cells grown in differentiation non-permissive conditions (HT-29 Glc+) whatever the phase of growth studied. In contrast, HT-29 cells grown in differentiation permissive conditions (HT-29 Glc-) display a normal pattern of N-glycan processing in both the exponential and the stationary phase of growth. We also show that both growing and confluent HT-29 Glc+ cells accumulate Man GlcNAc2 species, thus suggesting that there is an important regulatory point at this level. We therefore conclude that the N-glycan processing may be used as an early biochemical probe for the enterocytic differentiation of HT-29 cells. Whether these early changes result from an early metabolic regulation or are the consequence of a genetic control remains to be studied.
Ogier-Denis
E
E
Unité de Recherches sur la Biologie et Pathologie Moléculaires des Glycoprotéines, (INSERM U180), UER des Saints-Pères, France.
Bauvy
C
C
Aubery
M
M
Codogno
P
P
Sapin
C
C
Rousset
M
M
Zweibaum
A
A
Trugnan
G
G
D001216:Asparagine / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D004734:Energy Metabolism; D005947:Glucose / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008358:Mannose / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000378:metabolism*
D006023:Glycoproteins; D009844:Oligosaccharides; D001216:Asparagine; D005947:Glucose; D008358:Mannose