Assessment of Sialyltransferase Expression in Human Breast Multiplex Reverse Transcription Polymerase Chain Reaction

Increased sialv lation, especially involving the Sialyl-Lewis" and SialylLewisx determinants, has been reported in breast cancer. A multiplex reverse transcription-PCR method was used here to determine the expres sion of five sialyltransferases (ST3Gal HI, ST6Gal I, ST3Gal IV, ST3Gal I, and ST3Gal II) in 49 patients surgically treated for locoregional breast cancer. We assessed the relationship between these expressions and clin ical, pathological, and biological features. The most expressed sialyltransferase was ST3Gal III, which is involved in Sialyl-Lewis" synthesis. ST3Gal III expression was positively correlated to ST6Gal I and ST3Gal IV expressions, to tumor size, and to the number of involved axillary nodes. Patients with high ST3Gal III expression had a shorter overall survival. High ST6Gal I expression was associated with histoprognostic grade III. ST6Gal I expression was negatively correlated to expression of progesterone receptor. In conclusion, high ST3Gal III and ST6Gal I expressions in human breast tumors are associated with poor prognosis markers.