The ST3Gal.I expression correlates with the sialyltransferase activity towards T antigen in bladder cancer cell lines. A: The relative mRNA levels of ST3Gal.I, ST3Gal.II and ST3Gal.IV genes were analyzed in 5637, HT1376, MCR and T24 bladder cancer cell lines, by Real Time PCR. Values infer the number of mRNA molecules of a certain gene per 1000 molecules of the average of the endogenous controls (β-actin and GAPDH). Results are the mean of 3 independent assays. B: The sialyltransferase activity towards Galβ1,3GalNAcα1-O-Benzyl glycoside was assessed in sample homogenates of 5637, HT1376, MCR and T24 bladder cancer cell lines, as described in the Methods section. In the four analyzed bladder cancer cell lines, the ST3Gal.1 mRNA levels are correlated with the observed sialyltransferase activity towards the T antigen (r = 0.99; p = 0.001).