| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-154 |
Sentence |
denotes |
The relative activities of the C2GnT1 and ST3Gal-I glycosyltransferases determine O-glycan structure and expression of a tumor-associated epitope on MUC1. |
| T2 |
155-248 |
Sentence |
denotes |
In breast cancer, the O-glycans added to the MUC1 mucin are core 1- rather than core 2-based. |
| T3 |
249-502 |
Sentence |
denotes |
We have analyzed whether competition by the glycosyltransferase, ST3Gal-I, which transfers sialic acid to galactose in the core 1 substrate, is key to this switch in MUC1 glycosylation that results in the expression of the cancer-associated SM3 epitope. |
| T4 |
503-668 |
Sentence |
denotes |
Of the three enzymes known to convert core 1 to core 2, by the addition of GlcNAc to GalNAc in core1 C2GnT1 is the dominant enzyme expressed in normal breast tissue. |
| T5 |
669-797 |
Sentence |
denotes |
Expression of C2GnT1 is low or absent in around 50% of breast cancers, whereas expression of ST3Gal-I is consistently increased. |
| T6 |
798-874 |
Sentence |
denotes |
Mapping of ST3Gal-I and C2GnT1 within the Golgi pathway showed some overlap. |
| T7 |
875-1064 |
Sentence |
denotes |
To examine functional competition, the enzymes were overexpressed in T47D cells, which normally make core 1-based structures, have no detectable C2GnT1 activity and express the SM3 epitope. |
| T8 |
1065-1232 |
Sentence |
denotes |
Overexpression of C2GnT1 resulted in loss of binding of SM3 to MUC1, accompanied by a decrease in the GalNAc/GlcNAc ratio, indicative of a switch to core 2 structures. |
| T9 |
1233-1362 |
Sentence |
denotes |
Transfection of a C2GnT1 expressing line with ST3Gal-I restored SM3 binding and reduced GlcNAc incorporation into MUC1 O-glycans. |
| T10 |
1363-1535 |
Sentence |
denotes |
Thus, even when C2GnT1 is expressed, the O-glycans added to MUC1 become core 1-dominated structures, provided expression of ST3Gal-I is increased as it is in breast cancer. |
